Ivancho Naletoski Anthony G. Luckins Gerrit Viljoen *Editors*

Nuclear and Radiological Emergencies in Animal Production Systems, Preparedness, Response and Recovery

Nuclear and Radiological Emergencies in Animal Production Systems, Preparedness, Response and Recovery

Ivancho Naletoski • Anthony G. Luckins Gerrit Viljoen Editors

# Nuclear and Radiological Emergencies in Animal Production Systems, Preparedness, Response and Recovery

*Editors* Ivancho Naletoski Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture Animal Production and Health Section Vienna, Austria

Gerrit Viljoen Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture Animal Production and Health Section Wien, Wien, Austria

ISBN 978-3-662-63020-4 ISBN 978-3-662-63021-1 (eBook) https://doi.org/10.1007/978-3-662-63021-1

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Anthony G. Luckins Schiehallion Blairgowrie, UK

## **Foreword**

Nuclear and radiological emergencies (NREs) can result in the release of substantial amounts of radioactive substances (radionuclides) into the environment. Through their migration in the environment, radionuclides may contaminate various commodities affecting animal production systems, thus posing a risk for food safety and security.

The International Atomic Energy Agency (IAEA) has already established standards for preparedness and response to NREs (GSR Part 7), which defne the requirements for the management of nuclear and radiological emergency responses at national and local levels. Additionally, international conventions such as the "Convention on Early Notifcation of a Nuclear Accident", the "Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency" as well as the "Joint Radiation Emergency Management Plan of the International Organizations" (EPR-JPLAN) emphasize the role of regional collaboration and the involvement of international organizations, such as IAEA, the Food and Agricultural Organization of the United Nations (FAO) and the World Health Organization (WHO) in the management of NREs.

Veterinary authorities, as key stakeholders of animal production systems, have already a well-defned international structure and standards established to monitor the production processes on a daily basis (www.oie.int). These standards are aimed at ensuring food security and safety of the products of animal origin aimed for human consumption. Moreover, the standards and regulations developed and accepted by the World Organization for Animal Health (OIE) are transferred directly or through other relevant international organizations (primarily FAO) into the national legislations of countries and are consequently implemented at national levels. These administrative acts specify the technical roles of all offcially designated institutions in Member States (MS), and usually address the roles and responsibilities of the competent authorities (head veterinary offces), laboratories, feld veterinary services, farmers and processing industries.

In the context of preparedness for response to emergencies in general (emergency/disaster management), there are also well-established strategies at international level [Hyogo Framework for Action 2005–2015 and Sendai Frameworks for Disaster Risk Reduction 2015–2030 of the United Nations Offce for Disaster Risk Reduction (UNDRR), FAO]. For veterinary authorities, however, there is still no technical link between the IAEA standards for response to NREs and disaster management plans at international and national levels. To achieve this, clear mapping of the stakeholders and their roles in NREs is needed, such as farming entities (structure and farming systems), designated offcials (nuclear safety authorities) and the executive institutions, including the veterinary authorities through their offcial designees.

This book elaborates the threats to animal production systems before, during and after NREs, the risks of contamination of products of animal origin, and the procedures to prevent placement of contaminated animal products on the market for human consumption. It also presents the key decision-making criteria and management options for response to NREs. This publication defnes the roles of the veterinary authorities in mitigating or preventing public health risks caused by NREs.

Director Qu Liang Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture, Vienna, Austria

## **Acknowledgements**

The editors want to thank to their colleagues in the Department of Nuclear Safety and Security/Incident and Emergency Center at IAEA – Ms Elena Buglova, Mr Ignacio Ramon De La Vega, Mr Motomitsu Kunihiko and Ms Kouts Katerina as well as Ms Brown Joanne in the Division of Radiation, Transport and Waste Safety for the critical review and the useful advises to improve the content of the book.

Special thanks to the colleagues in the Department of Technical Cooperation at IAEA, especially the Programme Management Offcer Mr. Christoph Henrich (Project: RER/9/037: Enhancing National Capabilities for Response to Nuclear and Radiological Emergencies; Component: Re-enforcing Veterinary Authorities to Respond to Nuclear Emergencies) for the enthusiastic support during the development of this book.

## **Introduction**

Major nuclear and radiological emergencies (NREs) can have implications at local, national and international level. The response to NREs requires a competent decision-making structure, clear communication and effective information exchange.

National veterinary services have the responsibility to plan, design and manage animal production system in their countries. These activities cover animal health, animal movement control, production control and improvement, and control of the products of animal origin before their placement on the market.

Release of radionuclides after NREs can cause substantial contamination in the animal production systems. Critical responsibility of veterinary authorities is therefore to prevent such contamination, establish early response mechanisms to mitigate the consequences and prevent placement of contaminated products of animal origin on the market for human consumption.

This book summarizes the concepts of preparedness and response to emergencies/disasters in general (including nuclear and radiological emergencies), a short, refresher course in radiobiology, migration of the radionuclides upon release in the environment, as well as the critical technical points for effective management of nuclear and radiological emergencies.

The book is primarily aimed for the national veterinary services in member states of the International Atomic Energy Agency.

## **Contents**


## **About the Contributors**

**Viktar S. Averyn** (PhD) is Doctor of Biological Sciences, professor, and winner of the prize given by the government of the Russian Federation in the feld of science and technology. He is dean of the Faculty of Biology at F. Skaryna Gomel State University. His main scientifc activities are aimed at developing effcient and economically viable ways of sustainable development of contaminated areas, improving measures to protect the population in case of accidents at nuclear power plants and long-term residence in the territory of radioactive contamination. Scientifc support and maintenance of rehabilitation and protective measures.

**Brenda Howard** (PhD, MBE) has worked for 40 years on environmental transfer processes of radionuclides (especially for farm animals) and mitigation of the impact of the Chernobyl and Fukushima Daiichi nuclear accidents. Professor Howard has contributed to, and edited, a variety of IAEA publications and chaired working groups under EMRAS and MODARIA programmes. She also contributes as an expert reviewing information on terrestrial and freshwater ecosystems contaminated after the Fukushima Daiichi accident as part of the Expert Group for the United Nations Scientifc Committee on the Effects of Atomic Radiation (UNSCEAR). She has an honorary professorship at the University of Nottingham and is a fellow of the Centre for Ecology and Hydrology.

**Kevin Kelleher** (PhD) works in the Emergency Preparedness Unit of Ireland's Environmental Protection Agency. Dr Kelleher's work includes the development of procedures and training of people responding to nuclear or radiological emergencies in Ireland and is a member of the IAEA's Emergency Preparedness and Response Standards Committee. Prior to this, Dr Kelleher worked in the Radiation Monitoring Unit of the EPA monitoring the levels of radioactivity in the environment and has assisted the IAEA in Technical Co-operation Projects in Fukushima measuring the activity concentrations in the marine environment and advising the local government of the Fukushima prefecture on the display of radioactivity monitoring data to the public after the Fukushima Daiichi accident.

**Anne Nisbet** (PhD, CRadP) is radiation recovery lead at Public Health England. Dr Nisbet has over 30 years' experience in radiation protection at Public Health England and its predecessor organization, the National Radiological Protection Board. She has worked as an expert in the feld of environmental assessments, radioecology, emergency planning, response and recovery, stakeholder engagement, and communication strategies. At the national level, she has the responsibility to provide advice to the UK for public health protection in the event of radiation emergencies. Since 2005, Dr Nisbet has taken the lead on producing UK and European Recovery Handbooks and contributed to the development of the US 'Rad Decon App'. Internationally, she has served as a member of the International Commission on Radiological Protection (ICRP) Committee 4 since 2013 as well as on its various task groups. She has also worked for a wide range of other international organizations/bodies, such as International Atomic Energy Agency, Nuclear Energy Agency and US National Council on Radiation Protection and Measurements. Dr Nisbet has a BSc (Hons) degree in applied biology and a PhD in environmental geochemistry, both from London University, Imperial College of Science and Technology. She carried out her postdoctoral work on biosphere studies at Macaulay Land Use Research Institute in Aberdeen.

**Gary Vroegindewey** DVM, MSS, DACVPM. Dr Vroegindewey is director of the One Health Program at Lincoln Memorial University College of Veterinary Medicine. Dr Vroegindewey is a veterinarian with a Master of Strategic Studies degree and is specialty boarded in the American College of Veterinary Preventive Medicine. He has consulted with the World Organization for Animal Health (OIE), World Health Organization, UN Food and Agriculture Organization, and International Atomic Energy Agency. Dr Vroegindewey previously served in the United States Department of Defense as Director, Veterinary Service Activity, and Assistant Corps Chief, US Army Veterinary Corps, and Subject Matter Expert on Disaster Medicine and Bioterrorism.

## **Abbreviations**



## **Chapter 1 National Veterinary Services Roles and Responsibilities in Preparing for and Responding to Nuclear and Radiological Emergencies**

**Gary Vroegindewey**

National Veterinary Services have a wide range of regulatory and operational responsibilities as directed by their respective countries. These responsibilities could include animal health, animal welfare, food safety, zoonotic disease surveillance and control, import and export regulations, trade in livestock and livestock products, disaster management, and other functional areas (OIE 2017). In many cases veterinary services are resourced to meet minimal capability needed for animal health and trade. Therefore, veterinary services may lack the authorities and capacities to meet the unique requirements presented in disaster situations including NREs.

Disasters by defnition are those events that exceed the normal capacity to respond at some level (Akshat 2017). Animals and animal-related issues are increasingly part of disaster management and risk reduction due to their economic, health, welfare, and social aspects (PETS ACT 2006). In addition to the livestock and food chain issues, National Veterinary Services may be called on to prepared for and respond to NREs in other special animal categories such as search and rescue animals, service animals, laboratory animals, zoo and aquatic exhibition animals, and wildlife.

Veterinary services are generally trained and experienced in dealing with biological animal disasters such at the incursion of a transboundary disease of economic importance to the livestock industry such as African swine fever or foot-and-mouth disease. However, there is less experience and capability to deal with non-biological disasters such as foods, drought, earthquakes, tornadoes, volcanic eruption, and extreme weather events. The foundation for National Veterinary Services in general, and disaster preparedness and response specifcally is the legislative framework and authorities to perform specifed functions. National legislation

G. Vroegindewey (\*)

College of Veterinary Medicine, Lincoln Memorial University, Harrogate, TN, USA e-mail: Gary.Vroegindewey@lmunet.edu

<sup>©</sup> The Author(s) 2021 1

I. Naletoski et al. (eds.), *Nuclear and Radiological Emergencies in Animal Production Systems, Preparedness, Response and Recovery*, https://doi.org/10.1007/978-3-662-63021-1\_1

needs to be reviewed to ensure veterinary service disaster management and disaster risk reduction authorities are included. National disaster preparedness and contingency plans should address the animal health and welfare component and detail the roles and responsibilities of each department and ministry including the lead authority for each type of event. National Veterinary Services should use these documents to develop an all-hazards approach for their specifc disaster preparedness contingency plans (AVMA 2012). Technological disasters such as chemical spills, toxic gas releases, and NREs present an even greater challenge since many veterinary services will not have authorities and capabilities established for these types of events (Vroegindewey 2014).

Global natural and climate disasters in 2017 affected over 95 million people with over 9600 deaths, costing over \$335 billion dollars (US) (CRED 2017). Many if not most of these disasters have an animal component that requires veterinary response. The need for effective local, national, regional, and international capabilities is highlighted by the United Nations Offce for Disaster Risk Reduction (UNISDR) Sendai Framework for Disaster Risk Reduction 2015–2030 (UNISDR 2015) that builds on the previous Hyogo Framework for Action 2005–2015 Building the Resilience of Nations and Communities to Disasters (UNISDR 2005). These two documents provide a framework for nations to build their own disaster preparedness, disaster contingency, and disaster risk reduction plans. Included in the Sendai framework are seven global targets:


In addition, there are four priorities for action including understanding disaster risk, strengthening disaster risk governance, investing in disaster risk reduction, and enhancing disaster preparedness. These targets and priorities for action can be used by intergovernmental organizations, governments, and National Veterinary Services as a roadmap toward building effcient and effective disaster management programs including those addressing NREs.

A study conducted by the World Organization for Animal Health (OIE) in 2014 on the preparedness of National Veterinary Services to respond to natural disasters and bioterrorism demonstrated signifcant gaps in authorities and capabilities (Vroegindewey 2014). The study surveyed European and Western Asian countries' National Veterinary Services with 48 responses out of 53 countries queried. There was a wide range of responses on national legislation and incorporation of animalfocused disaster management into National Disaster Response Plans. Twenty-one percent of the respondents indicated that no national legislation addressed animals in disasters. Sixty-six percent of the countries indicated the absence of guidelines,

standards, handbooks, and references for dealing with disasters. While livestock was covered by 81% of the National Disaster Response Plans, there were fewer plans that covered companion animals (52%), zoo and aquatic exhibit animals (52%), and wildlife (42%). A review of the OIE list of Performance of Veterinary Services publicly published evaluations indicated only 4 of 27 National Veterinary Services had the highest level of residue surveillance programs including radionuclides and 17 of 27 had no or very limited capacity reported (OIE 2019). These numbers underscore the scope of work that veterinary services will need to accomplish to meet the needs of society in disaster scenarios including NREs. Many National Veterinary Services did not use guidelines for disaster preparedness and response despite the availability of numerous international publications and guidelines for National Veterinary Services to meet these disaster-focused operational requirements.

OIE has published general guidelines such as OIE Guidelines on Disaster Management and Risk Reduction in Relation to Animal Health and Welfare and Veterinary Public Health (OIE 2016). This guideline provides general principles for disaster management. The OIE Terrestrial Animal Health Code 2017 (OIE 2017) provides high-level guidance on legislative authorities and operational guidelines for animal disease incursions but limited information on disasters with the primary focus on mass depopulation and disposal of animals in natural disaster and disease situations. There are no specifc references for NREs included. The United Nation Food and Agricultural Organization (FAO) has published the Good Emergency Management Practice: The Essentials, a comprehensive guide for preparing for and responding to animal health emergencies (FAO 2011). This detailed guide focuses on animal health emergencies with an emphasis on Transboundary Animal Diseases (TAD). It can be used as a framework to develop veterinary service preparedness plans, contingency plans, operational plans, and standard operating procedures (SOP), which can be used to easily integrate the requirements of the existing IAEA standards on preparedness and response to NREs.

One area that has not been signifcantly addressed in standards and guidelines is the need for training in behavioral health resilience and providing medical and behavioral health support to responders before, during, and after the termination of the emergency phases of a disaster event.

Disaster risk management (DRM) has emerged as a focus in the international disaster management for identifying risk and risk analysis to prepare for, mitigate, and respond to disasters. FAO published a guideline disaster risk management systems analysis (FAO 2008) that details the process for DRM and provides a toolbox for development of protection strategies in line with IAEA requirements.

NREs such as Chernobyl, Fukushima Daiichi, Kyshtym, Windscale, and Three Mile Island illustrate the potential for radiological events that would require national veterinary service preparedness and response. The IAEA has published numerous requirements and guidelines that are relevant to the National Veterinary Services for NREs. The IAEA publication Joint Radiation Emergency Management Plan of the International Organizations provides (IAEA 2013) high-level national and regional guidance for management of NRE with specifc functions and organizational links for information and support (IAEA 2002a). Food and food chain issues are addressed in this document.

The IAEA safety standards detail general requirements and specifc guidelines which are applicable to veterinary service responders. IAEA safety standard Preparedness and Response for a Nuclear or Radiological Emergency GSR-7, 2015, outlines the general high-level requirements for preparing for and responding to NREs (IAEA 2015). This set of requirements include:


The IAEA General Safety Guide GSG-2, 2011, Criteria for Use in Preparedness and Response for a Nuclear or Radiological Emergency (IAEA 2011) provides a starting point for veterinary services to train personnel. The safety guide was cosponsored by FAO, the World Health Organization (WHO), the Pan American Health Organization (PAHO), and the International Labour Offce (ILO). The overall goal of GSG-2 is to "Present a coherent set of generic criteria that form a basis for developing the operational levels needed for decision making concerning protective actions and other response actions necessary to meet the emergency response objectives."

In addition to the criteria, Operational Interventional Level (OIL) provides guidance for responders to take appropriate actions. The IAEA defnes the OILs (IAEA 2017) as "A calculated level, measured by instruments in the feld or determined by laboratory analysis, that corresponds to an intervention level or action level. OILs are typically expressed in terms of dose rates or of activity of radioactive material released, time integrated air concentration, ground or surface concentration or activity concentrations of radionuclides in environmental food or water samples. An OIL is a type of action level that is used immediately and directly (without further assessment) to determine the appropriate protective actions on the basis of an environmental measurement."

OIL values for food, milk, and drinking water and associated actions provide a baseline for veterinary service decision-making in NREs (IAEA 2017). For example, at OIL 3 the criteria state:

If other food is available in the territories where OIL 3 is exceeded, stop consuming local produce (e.g., vegetables), milk from grazing animals and rainwater until they have been screened and declared safe. However, if restriction of consumption is likely to result in severe malnutrition or dehydration because replacement food, milk or water is not available, these items may be consumed for a short time until replacements are available.

These plain language criteria based on technical data provide National Veterinary Services with a defensible basis that can be used to explain the rationale for actions to be taken during a NRE.

The IAEA General Safety Guide GSG-11, 2018, Arrangements for the Termination of a Nuclear or Radiological Emergency (IAEA 2018b) provides guidelines that can be used by veterinary services to support operational response activities to assist in termination of the NRE. The document specifes that food, milk, and drinking water restrictions may continue after the termination of the NRE due to the continued risk to public health from products in the food chain and continued contamination to livestock, water, and foodstuffs. Monitoring will be required to ensure that agricultural products meet international trade standards. Comprehensive routine monitoring programs would be established until acceptable levels are achieved.

Codex Alimentarius has published the CODEX General Standard for Contaminants and Toxins in Food and Feed (CODEX STAN 193–1995) (CODEX 2015) that "lists the maximum levels and associated sampling plans of contaminants and natural toxicants in food and feed which are recommended by the CAC to be applied to commodities moving in international trade." It also states that "This standard includes only maximum levels of contaminants and natural toxicants in feed in cases where the contaminant in feed can be transferred to food of animal origin and can be relevant for public health." These guidelines are established for radionuclides in foods that are traded internationally for human consumption; however, the criteria can be applied in conjunction with a national standard which may be more restrictive (FAO-WHO 1989).

Guidelines and standards are critical to but not suffcient for effective NRE preparedness and response. National Veterinary Services need to integrate the requirements and recommendations of these standards. These requirements can be broken down into several organizational and operational components: legislation, leadership, organization, training, personnel, material, facilities, and fnance.

Specifc veterinary service contingency plans and standard operating procedures (SOP) for NREs should be developed and coordinated across government departments and ministries and be refected in the regional and national plans.

Veterinary leadership at the national, departmental, and ministry level must be committed to the preparation for, and response to NREs. Effective preparedness and response plan would include the following:


National Veterinary Services need to develop the organizational capacity to prepare for and respond to NREs. This includes developing the structures and personnel to work at the feld level, veterinary headquarter levels, and national emergency operations/coordination center. Trained designated personnel should be available to direct the veterinary response, communicate with national and regional authorities, and communicate with the public and animal health stakeholders as well as intergovernmental organizations (IGO) such as IAEA, OIE, FAO, WHO, and other IGO entities. Stakeholders are any individual or group that has an interest in any decision or activity of an organization (ISO 2010). Specifc units need to be identifed as the lead for each of the functions required for preparedness and response. Veterinary service personnel need to be identifed and trained to fll each contingency and operational plan role from feld work to headquarters to national operation centers. Laboratory personnel need to be trained and available to accomplish required analysis that may be outside the normal scope of day-to-day testing.

Training and education are key components for National Veterinary Services personnel. While generally experienced in dealing with day-to-day animal health and welfare issues, many are not trained and experienced in dealing with technological disasters such as NREs. The OIE recommendation guideline Competency of Graduate Veterinarians ("Day 1 graduates") to assure National Veterinary Services of Quality (OIE 2012) includes risk analysis as a competency but does not include competency in disaster management and disaster risk reduction nor specifc competencies in NRE capabilities. Therefore, new graduates and veterinary personnel will need to be trained, educated, and assessed on their skills in this arena. The training should include all personnel with a designated task in NREs. This includes leadership, headquarters, feld operations, laboratory, and other functional areas. The training can include technical training such as performing specifc laboratory analysis for radionuclides in animal or food samples; use of dosimeters and monitoring devices; proper use of personal protective equipment (PPE); decontamination, destruction, and disposal of contaminated food and nonfood materials; as well as nontechnical operational requirements. Examples of these nontechnical skills are risk assessment, risk communications, team building, working in national emergency operation centers, developing NRE contingency plans and SOP, and similar operational and organizational skillsets. Training is accomplished at the individual level, team level, and the organizational level. Training should be tracked by individual and organization to ensure there is complete coverage, newly hired personnel are trained, and refresher training and recertifcation are accomplished. The effectiveness of the training should be validated through testing and exercising the response plans and modifed to meet any training gaps that are identifed.

Veterinary personnel will need to be hired, trained, and assessed through all levels of the organization for both day-to-day operations and emergency operations such as a NRE event. Backup and reserve personnel need to be identifed for each function position. Critical positions should be identifed and resourced. Prior experiences with NRE events such as the Japan Earthquake-Tsunami-Fukushima reactor NRE demonstrate that veterinary service personnel in the affected area may be part of the affected population and unable to effectively perform their assigned duties; therefore a backup system of trained personnel should be available (OIE 2019). Increased workload during a NRE event may require adding personnel to cover the expanded scope of the event, and these added personnel will also require refresher or just-in-time training and equipping. Additional personnel required can be established through bilateral and regional mutual support agreements, establishing and training a reserve veterinary force, coordinating with the military as part of Military Support to Civilian Operations, and contracting civilian personnel.

National Veterinary Services will need to identify and acquire the material needed to train for and respond to NREs. Some of these materials are not used daily and may require special purchasing, stockpiling, and maintaining with a logistical distribution plan. The specifc types of items that may be required for a NRE include personal dosimeters, various types of in situ radiation monitoring devices, PPE, specialized radiation detection laboratory equipment, decontamination facilities, and other items. General emergency response materials will be required including communications equipment, computers, transportation assets, protective sheltering, animal handling equipment, and other general use items.

National Veterinary Services will need to identify and acquire facilities suffcient to conduct daily operations as well as contingency operations at the national, regional, and local level. Increased space may be required to meet the operational surge of response activity and may be pre-identifed and contracted for before an event. Emergency operation centers, increased laboratory requirements, decontamination areas, and animal carcass disposal sites must be considered. Contingency plans should identify critical infrastructure requirements and where those activities would take place in case that facility is within an exclusion zone.

Resourcing for National Veterinary Services to execute daily and emergent operations can be a challenge. Requirements for material, personnel, facilities, and operational activities should be identifed and brought to the national governmental level for legislative and funding support. Funding should be identifed for compensation for livestock that may need to be depopulated. Even if this level of funding is unlikely to be committed ahead of a disaster having a NRE, the existence of operational requirements document will expedite the release of funds.

National Veterinary Services have multiple resources beyond these guidelines to meet their operational requirements for NREs. OIE has expanded its disaster focus beyond animal diseases to include all hazards and is incorporating disaster training into its operational mandate (OIE 2016). The WHO, OIE, and FAO have collaborated on sharing responsibilities and coordinating global activities to address health risks at the animal-human-ecosystems interfaces. The focus of this Tripartite Concept Note is with animal and zoonotic diseases, but these collaborative relationships can be built upon for other disasters including NREs (FAO-OIE-WHO 2010). The IAEA has launched a program to support National Veterinary Services (IAEA 2018a) to address multiple facets of NRE preparedness and response including:


In addition, the Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture provides a concept of operations for notifcation and advisory information (IAEA 2019).

In 2005 the IAEA established the Incident and Emergency Centre (IEC – https:// www.iaea.org/about/organizational-structure/department-of-nuclear-safety-andsecurity/incident-and-emergency-centre) which is the global focal point for international emergency preparedness, communication, and response to nuclear and radiological incidents and emergencies, regardless of whether they arise from accident, negligence, or deliberate act. It is the world's center for the coordination of international emergency preparedness and response assistance. This center was created in response to the increase use of nuclear applications as well as emerging issues of the intentional malicious use of nuclear and radiological material. The IEC operates the IAEA Incident and Emergency System (IES). The IEC has four focus areas: IES Preparedness, IES Operation, Member State preparedness, and emergency communications and outreach. These last two focus areas could support National Veterinary Services to prepare for, and respond to NREs.

The IES includes training, emergency response exercising, and on-call capability. The IES activities are in compliance with the Convention on Early Notifcation of a Nuclear Accident (IAEA 2002b) and the Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency (IAEA 2002a), including operations of the IAEA Response and Assistance Network (RANET) and the ability to provide assistance mission upon request. They can assist Member States in developing their emergency preparedness and response framework and arrangements and provide safety standards and other technical guidance, education and training, and conducting Emergency Preparedness Reviews (EPREV missions). Specifc guidance and advice are available for essential tasks such as public communication for NREs through different IAEA publications on public communication and provision of training on these topics.

National Veterinary Services have critical roles in the preparedness and response to NREs to protect public health through control of products of animal origin. Assessment of current NRE risks, authorities, and capabilities would be a starting point to identify needs to meet governmental and societal responsibilities. The complexity of NREs in regard to National Veterinary Services can be seen in these four major NREs. Using these models of NREs, National Veterinary Services can do an assessment of what roles and responsibilities they would need to fulfll to have an effcient and effective response to meet their designated requirements.

The Kyshtym NRE in the Urals of the USSR was not a nuclear power plant accident; it was a release of radionuclides from a storage tank due to the failure of a cooling system. In the early phase after the NRE, the major contributor to the dose to humans was the internal exposure from 144Ce and 95Zr largely from crops (Standring et al. 2009). The maximum concentration of 144Ce or 95Zr in agricultural products on land closest to source areas (up to 20 km) reached 10–10,000 kBq/kg. For milk, the key isotope contributing to internal dose was long-lived 90Sr and, to a much lesser extent, 137Cs.

The Windscale NRE occuredwhen there was a buildup of Wigner energy which led to a fre that released radionuclides into the atmosphere in the north of the UK. Milk from dairy cows grazing adjacent lowland areas was contaminated by short-lived 131I, and a limit was set for radioiodine in milk of 0.1 μCi/L (3700 Bq/L). Sheep grazing upland areas were also contaminated by 137Cs. Po-210 may also have contaminated animal tissues but received little attention at the time.

The Chernobyl NRE occurred during an experiment when there was a surge of power followed by two explosions. There was a release of radionuclides over a period of 10 days, and the fallout contaminated large areas of the terrestrial environment with a major impact on both agricultural animal production and extensive animal production on poor land and game animal harvesting largely from forests. The most severely affected areas within 100 km of the nuclear power plant in the USSR were Ukraine, Belarus, and the Russian Federation, but other areas of Eastern and Western Europe were also contaminated, especially where the passage of the contaminated fallout in the atmosphere coincided with heavy rainfall. Therefore, problems with animal products were widely experienced not only within the former Soviet Union but also in many other countries in Europe (USSR Ministry Agriculture 1977).

After the Fukushima Daiichi NRE in Japan there was a system failure that led to a loss of cooling capacity of the power plant and resulted in several releases of radionuclides due to venting and hydrogen explosions. These releases contributed to contamination of agricultural areas. A key difference in this event compared with the other NREs is that animal products were relatively less contaminated because most dairy and other livestock animals are housed indoors in Japan.

Numerous national, regional, and international guidelines and resources are available to support the strengthening of National Veterinary Services to prepare for and respond to all disasters and particularly the unique complex issues present with NREs. Understanding the requirements, planning and preparing, training, and exercising National Veterinary Service capabilities and capacities will better prepare National Veterinary Services to perform their role and responsibilities in NREs. This will support the protection of animal health and welfare and veterinary public health and maintain the economic viability of the animal sector.

## **References**


The opinions expressed in this chapter are those of the author(s) and do not necessarily refect the views of the International Atomic Energy Agency, its Board of Directors, or the countries they represent.

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The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

## **Chapter 2 Short Refresher of Radiobiology**

**Viktar S. Averyn**

## **2.1 Atoms and Isotopes**

The atoms are built up of a nucleus, containing positive (protons) and neutral (neutrons) particles, surrounded by negative particles (electrons), circulating around the "atomic orbit". The number of the protons in the nucleus is giving the atomic number of the element (usually labelled as "Z"), and the sum of the neutrons and protons in the nucleus is giving the atomic or mass number of the element (usually labelled as "A"). The number in the electrons in the atomic orbit is always equal to the number of protons in the nucleus. However, as the mass of the electrons is almost equal to zero, they do not infuence the whole atomic mass.

The atomic number and the mass number are defning the properties of the atoms. The oxygen, for example, has eight protons and eight neutrons in the nucleus. If oxygen would have seven protons and seven neutrons, it would be nitrogen. The description of the atomic and mass numbers for atoms or isotopes in the periodic system is expressed by convention as shown in Fig. 2.1.

Some of the atoms have the same number of protons but different number of neutrons. Accordingly, their atomic number will be the same, but the mass number will be greater for the difference in the number of neutrons. These atoms are called **isotopes**. Isotopes, by their nature, can be stable (they do not decay) or, more often, unstable. A schematic example of the hydrogen isotopes deuterium and tritium is given in Fig. 2.2.

An example of the difference between atoms and their respective isotopes is shown in Table 2.1.

V. S. Averyn (\*)

Faculty of Biology, Francisk Skorina Gomel State University, Gomel, Belarus

<sup>©</sup> The Author(s) 2021 13

I. Naletoski et al. (eds.), *Nuclear and Radiological Emergencies in Animal Production Systems, Preparedness, Response and Recovery*, https://doi.org/10.1007/978-3-662-63021-1\_2


**Fig. 2.1** The mass number (A) is the sum of protons and neutrons in the nucleus of the atom, the atomic number (Z) is the number of protons in the nucleus and the neutron number is labelled as N. From practical reasons, atoms and isotopes are labelled only with A and Z numbers. The N number can be calculated as difference between A and Z (N = A−Z)

**Fig. 2.2** Schematic example of the hydrogen isotopes deuterium and tritium. (Adapted from IAEA 2004)



\*Note the different number of neutrons in the atoms (blue font) and their respective stable isotopes (red font)

## **2.2 Defnition of Radiation**

Radiation in its wider defnition refers to the energy emitted from various sources of the whole electromagnetic spectrum, such as heat, ultraviolet and visible light, microwaves, radio waves, x-rays, low-frequency radiation (such as used in alternate electric transmission, ultrasound thermal radiation) and ionizing radiation.

The ionizing radiation is the energy emitted from the atomic or subatomic structures in a form of waves (γ rays) or particles (α or ß), as a result of the instability of the isotopes. With the increase of the atomic and mass number, the neutron-toproton ratio increases, leading to formation of unstable isotopes or so-called "excited" state of the nucleus. Such isotopes tend to reach the "ground" state through the release of α, ß, or γ ionizing radiation (IAEA/WHO 2002).

## **2.3 Types of Ionizing Radiation**

**Alpha (α) particles (α decay, α radioactivity)** are produced when two neutrons and two protons (i.e. the nucleus of helium) are released from an excited nucleus of the isotopes with higher mass numbers (Z > 83, such as uranium, thorium and radium), as shown schematically in Fig. 2.3.

Therefore, the consequence of the α decay is decreased in the atomic number of the resulting decay (daughter) isotope by 2 and decrease in the mass number by 4 (Fig. 2.4).

The alpha particles are positively charged and because of their large mass (4), they cannot penetrate deep in the body. They can reach a distance of few centimetres through open air and cannot penetrate a sheet of paper. However, once entered in the body, usually by inhalation (lungs) or ingestion GI tract, they may cause short range but devastating consequences for the cell's structures (IAEA 2004). An example of alpha decay is shown in Fig. 2.5.

**Beta (**ß**) particles (**ß **decay,** ß **radioactivity)** are generated when the nucleus of an isotope has too many protons or neutrons (neutron or proton defciency, respectively) and are the result of the tendency of the nucleus to rearrange itself to a more stable confguration. Consequently, there are two types of ß decay, the ß− and ß+ decay.

## *2.3.1 ß− Decay*

In case when the nucleus has too many neutrons (it is proton defcient), the neutrons (n) are converted to protons (p) by releasing an electron (ß− particle), under high speed (approximately the speed of light) and a particle without mass and charge, called anti-neutrino (ΰ). The changes during ß− decay may be described as follows:

n → p + ß− + ΰ (Fig. 2.6)

Thus, during ß− decay, the atomic number of the resulting decay (daughter) isotope increases for 1, while the mass number remains the same (Fig. 2.7).

An example of ß− decay is shown in Fig. 2.8.

**Fig. 2.3** Schematic example of α decay. (Adapted from IAEA/ WHO 2002)

**Fig. 2.4** General pattern of the changes in the atomic and the mass number of the resulting decay product (Y) from the source isotope (X) during α decay

**Fig. 2.5** Examples of an α decay are shown in following examples. \*Note: the decrease in the atomic and the mass number of the resulting daughter isotopes (blue font) compared to the respective numbers of the decaying parent isotope (red fonts)

**Fig. 2.6** Schematic example of ß−decay. Note the change of the yellow-flled neutron (n) to a redflled proton (p), following the long arrow. (Adapted from IAEA/WHO 2002)

**Fig. 2.7** General pattern of the changes in the atomic number of the resulting daughter product (Y) from the source parent isotope (X) during ß− decay


**Fig. 2.8** Example of a ß− decay of 131I to 131Xe. \*Note the increase of the atomic number by maintaining the same mass number of the resulting daughter isotope (blue font) compared to the respective numbers of the decaying parent isotope (red fonts)

## *2.3.2 ß+ Decay*

In case when the nucleus has too many protons (it is neutron defcient), the protons (p) are converted to neutrons (n) by releasing a positron (positively charged electron, ß+ particle), under high speed (approximately the speed of light) and a particle without mass and charge, called neutrino (υ). The changes during ß+ decay may be described as follows:

p → n + ß+ + υ (Fig. 2.9)

Thus, during ß+ decay, the atomic number of the resulting decay (daughter) isotope decreases for 1, while the mass number remains the same (Fig. 2.10).

An example of ß+ decay is shown in Fig. 2.11.

## *2.3.3 Electron Capture*

In case when the nucleus has protons in excess (situation similar to the ß+ decay), the protons (p) may be converted to neutrons (n) by the phenomenon called electron capture. In such cases, the orbital electrons are captured by the protons which convert to neutrons by emitting a neutrino (υ).

The changes during electron capture may be described as follows:

#### p + e → n + υ (Fig. 2.12)

Thus, during the electron capture (similar as during the ß+ decay), the atomic number of the resulting decay (daughter) isotope decreases for 1, while the mass number remains the same (Fig. 2.13). An example of electron capture is shown in Fig. 2.14.

**Fig. 2.9** Schematic example of ß+ decay. Note the change of the red-flled proton (p) to a yellowflled neutron (n), following the long arrow. (Adapted from IAEA/WHO 2002)

**Fig. 2.10** General pattern of the changes in the atomic number of the resulting decay product (Y) from the source isotope (X) during ß+ decay

**Fig. 2.11** Example of a ß+ decay of 18F to 18O. \*Note the decrease of the atomic number by maintaining the same mass number of the resulting daughter isotope (blue font) compared to the respective numbers of the decaying parent isotope (red fonts)

**Fig. 2.12** Schematic example of the electron capture. Note the orbital electron is captured by the proton from the nucleus. (From IAEA/ WHO 2002)


**Fig. 2.13** General pattern of the changes in the atomic number of the resulting decay product (Y) from the source isotope (X) during electron capture

**Fig. 2.14** Example of an electron capture of the 125I to 125Te. \*Note: the decrease of the atomic number by maintaining the same mass number of the resulting daughter isotope (blue font) compared to the respective numbers of the decaying parent isotope (red fonts). (From IAEA/ WHO 2002)

During the electron capture, specifc x-rays are emitted, and, in some cases, where an excess of energy remains, γ rays are also emitted (IAEA/WHO 2002).

**Gamma (γ) rays (γ radioactivity)** are high-energy electromagnetic rays (similar to x-rays) which are produced in the atomic nucleus. They have no electrical charge and an extremely high frequency (over 1019 Hz) and energy (over 100 keV). For this reason, they have highly penetrating potential. Their release may be induced through excitation of the atomic nucleus by other decay processes, such as α or ß decay (Fig. 2.15).

**Fig. 2.15** Example of gamma decay of the 60Co to 60Ni


## **2.4 Physical Half-Life of Radioactive Isotopes**

Each radioactive isotope, by emission of certain particles and/or rays, expends the energy (radioactivity) and tends towards stabilization. The time required to expend half of the radioactivity is called physical half-life of the radioactive isotope and is most commonly labelled as *T*1/2. Each isotope has specifc physical half-life; thus the calculation of *T*1/2 is based on the isotope constant, as follows:

$$T\_{1/2} = \text{Ln2} \,\%\text{ }\lambda.$$

where *λ* is a radioactive constant specifc for the isotope.

Very often, it is necessary to predict the activity of certain isotope, after a certain time (*A*). This can be also calculated, based on the initial radioactivity (*A*0), the isotope constant (*λ*) and the elapsed period (*t*), as follows:

$$A = A\_0 + e^{(-\\\\\lambda x)},$$

where the "*e*" is the natural logarithm and has the value of 271,828.

A list of the most important isotopes, the ionizing particles/rays are emitting, and the physical half-lives are shown in Table 2.2. The schematic overview of the radioactive decay of isotopes with short (131I, 8 days), long (137Cs, 30 years) and very long ( 239Pu, 24,390 years) half-life is shown in Fig. 2.16.

## **2.5 Biological Half-Life of the Radioactive Isotopes**

Once entered into the body of animals, via the intestines or inhalation, a part of the ingested radionuclides is absorbed into the blood stream, and the rest is excreted via the faeces or exhaled. The amount entered into the blood stream is distributed among the different tissues. The distribution pathways vary for different isotopes. Some isotopes are distributed throughout the body, and some are incorporated into certain organs. Absorbed radionuclides can be excreted in urine or endogenously excreted in the faeces. The time required for a radioactive isotope to lose half of its activity in the body is called the biological half-life (*T <sup>b</sup>* 1 2/ ) which depends on the metabolic characteristics of each isotope and is not related to the physical half-life of the isotope (*T <sup>p</sup>* 1 2/ ). Some of the isotopes may have short *T*1/2 and long *<sup>T</sup> <sup>b</sup>* 1 2/ , and the opposite also occurs.


**Table 2.2** List of most important radioisotopes, occurring after a NRE, their mass number, type of decay and the physical half-life

**Fig. 2.16** Schematic overview of the radioactive decay of three isotopes with different half-life (simulation of a 5-year period)

## **2.6 Effective Half-Life of the Radioactive Isotopes in the Body of Animals**

The effective half-life (*T*1 2/ eff ) is the time required to lose half of the overall activity in the body and is a result of the interrelation between the *T <sup>p</sup>* 1 2/ and *T <sup>b</sup>* 1 2/ . The *T*1 2/ eff can be calculated according to the following equation:

$$T\_{1/2}^{\text{eff}} = \left(T\_{1/2}^{\rho} \times T\_{1/2}^{\rho}\right) / \left(T\_{1/2}^{\rho} + T\_{1/2}^{\rho}\right)$$

Example: Iodine-131 has a *T <sup>p</sup>* 1 2/ of 8 days and a *T <sup>b</sup>* 1 2/ of 138 days. The *T*1 2/ eff can be calculated as:

$$T\_{1/2}^{\text{eff}} = \left(8 \times 138\right) / \left(8 + 138\right) = 1 \,\text{104} / 146 = 7.6 \,\text{days}.$$

## **2.7 Decay Chains and Ingrowth**

The radioactive isotopes undergo radioactive decay through numerous transformations. Until the last decay, with each transformation, these radionuclides emit particles (energy) and become another isotope (Fig. 2.17). This stepwise decay ends with formation of a stable atom or isotope and is called decay chain of the specifc isotope.

The result of the decay chain is a dynamic change of the concentration of different between-products (isotopes); unit of the fnal stable product is formed. Through this process, the concentration of the source nucleotide continuously decreases, and the concentration of between products increases, until the fnal, stable element achieves the maximal concentration. This process is called ingrowth (Fig. 2.18).

Information and knowledge related to the decay chain and the ingrowth are of utmost importance for the waste management or post-accident mitigation strategies, even though some of these processes may continue over thousands of years!

There are three natural (uranium, thorium and actinium) and one artifcial (americium) decay series, for which detailed information on the type of radiation, energy and half-lives of parent and daughter isotopes are calculated (US Department of Energy 1997). Detailed calculation of the decay and growth of individual parent and daughter isotopes, respectively, is given in IAEA/UNESCO (2000).

## **2.8 Units of Radioactivity**

The radioactivity of the isotopes represents decays per time unit. According to the SI system, the measure for radioactivity is Becquerel (Bq) and represents one disintegration per second. The conventional unit, Curie (Ci), has been defned as activity of 1 g of 226Ra (IAEA 2004) and equals 37 × 109 disintegrations per second. Accordingly, 1 Ci = 3.7 × 1010 Bq or 1 Ci = 3.7 GBq and 1 Bq = 2.703 × 10−11 Ci.

## **2.9 Specifc Radioactivity**

Specifc radioactivity is the radioactivity per mass or volume of certain material. It is expressed as Bq/kg (mass) or Bq/m3 (volume). The legislation limits for animal products are based on the specifc radioactivity.

## **2.10 Radiation Dose**

The radiation dose is the amount of radiation energy (amount of radiation exposures) absorbed by the body and is defned by two variables:


**Fig. 2.19** A schematic example of the capacity for penetration of α and β particles and γ rays through different materials (IAEA 2004)

tance (linear energy transfer or LET). The LET depends on the size of the particles, their charge and their energy. Larger and charged particles (α and β) have higher LET compared to γ rays. Schematic example of the capacity for penetration of the ionizing radiation through different substances is shown in Fig. 2.19.

The biological effect of different radiation particles/rays is measured by the quality factor (Q). The Q factor is a correction for different types of radiation particles/rays, used to correct for the biological effect caused by these particles. For electrons, x-rays and gamma rays, the Q is taken to be 1; for alpha particles it is 20 and for neutrons varies from 5 to 20, depending on neutron energy (Table 2.3). The biological impact is specifed by the dose equivalent (H), which is the product of the absorbed dose D and the quality factor (Radiation weighting factors) Q (H = QxD). Consequently, if an organism has absorbed a dose of 1 Gy of gamma rays, the dose equivalent would be 1 Sv, whereas for the same absorbed dose of alpha particles, the dose equivalent would be 20 Sv. In older literature, instead of Sievert, the Rem unit is used, which is a product of Rads × Q. The Sievert is 100 times higher than the Rem (1 Sv = 100 Rem).

## **2.11 Effective Dose Equivalent**

Even if same biological dose is absorbed by different organs or biological systems, the overall risk may vary depending on the organ/biological system affected. The effective dose equivalent is therefore discounted for the appropriate weighting factor, in order to refect the overall risk. Estimated weighting factors for some parts of the body are shown in Table 2.4.

**Table 2.3** The quality factors (Q) of different types of ionizing (Gusev et al. 2001)



#### **Table 2.4** The estimated weighting factors for selected organs of the human body (ICRP 2012)

## **2.12 Lethal Dose**

The effective dose equivalent that will cause death in 50% of the exposed individuals is called 50% lethal dose (LD50), and it is different for different species.

LD50 in different animal species is shown in Table 2.5.

A simplifed way for interpretation of the units of radiation mentioned above is shown in Table 2.6.

## **2.13 Interaction of the Ionizing Radiation with the Matter**

Based on their mass and the energy of the ionizing radiation, different sources have different capacities of penetration through the matter. They have also different biological action when entered into the body of humans and animals.

During penetration, the ionizing particles are causing electrical interactions with the matter, either by interactions with the electrons (α, β and γ) or interactions with the atomic nuclei (neutrons). The energy that is lost during the penetration of the ionizing radiation causes vibrations of the atomic and molecular structures, which results in short heat production in biological tissues. Ionization and the consequent


**Table 2.5** LD 50% for different animal species (Gy) (Yarmonenko 1988)

**Table 2.6** Illustration of simplifed ways of interpretation of different units for measuring radiation exposure (Gusev et al. 2001)


chemical changes are actually the reason for the harmful biological effects of the ionizing radiation (IAEA 2004).

## **2.14 The Sources of Man-Made Environmental Contamination**

Continuous nuclear tests (UNSCEAR 1977), radiation accidents and large-scale nuclear disasters (Dyachenko 2008) have led to the omnipresent pollution of the biosphere by radioactive hazardous substances such as 137Cs and 90Sr. Nowadays, the typical density of land contamination caused by these radionuclides makes up a few tens of kBq/m2 .

Four hundred twenty-three nuclear explosions were conducted in the atmosphere during the period of nuclear testing in 1945–1980. Altogether, they discharged around 5.9 × 1917 Bq of 90Sr and approximately 9.5 × 1017 Bq of 137Cs. The presenttime deposition density of these radionuclides in the mid-latitudes of the Northern Hemisphere, from both nuclear testing and global fallouts, makes up 1.1 and 1.8 kBq/m2 , respectively.

The radiation accident of 27 September 1957 that had occurred at "Mayak" reprocessing nuclear facility in Chelyabinsk region, USSR, involved the explosion of 70–80 tons of high-activity nuclear wastes with a total activity of around 7.4 × 1017 Bq, of which approximately 7.4 × 1016 Bq was released into the environment. The contribution of 90Sr and 137Cs in the total discharged activity was 2 × 1015 and 3 × 1013 Bq, respectively. The extensive radioactive trace with a total area over 1000 km2 and 90Sr contamination level of 74 kBq/m2 had spread over USSR's Chelyabinsk, Sverdlovsk and Tyumen regions (Aleksakhin 2006; Avramenko et al. 1997).

On 26 April 1986, the radiation disaster at the Chernobyl NPP was accompanied by powerful releases of radioactive materials into the atmosphere. The total activity of radioactive materials released from the nuclear core in the accident was (1–2) × 1018 Bq, with a share of 137Cs equalling to 3.6 × 1016 Bq and that of 90Sr equalling to 8.0 × 1015 Bq (IAEA 2008).

Two hundred sixty-fve thousand hectares of the agricultural lands in Belarus are contaminated by either 137Cs or and 90Sr with the deposition densities of above 1480 kBq/m2 and 111 kBq/m2 , respectively (CMRB 1997). A particular challenge for the country has been the production of foods in compliance with the regulation values in the areas where land contamination by cesium-137 is 5–40 Ci/km2 . The total area of such lands in the republic is 415.6 thousand hectares, of which 35.7 thousand hectares is simultaneously contaminated by 90Sr with a density of 1–3 Ci/ km2 (Annenkov and Averin 2003).

The most important and equally complicated task of the regional development strategy is about overcoming the consequences of the Chernobyl disaster. The strategy of sustainable development of the areas affected by radioactive contamination should be built with taking into account the need to improve the living standards and the overall wellbeing of the residents on the basis of environmentally radiological and socio-economic recovery of such areas. The following efforts are planned to help to reach this objective:


## **References**


The opinions expressed in this chapter are those of the author(s) and do not necessarily refect the views of the International Atomic Energy Agency, its Board of Directors, or the countries they represent.

**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 3.0 IGO license (http://creativecommons.org/licenses/by/3.0/igo/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the International Atomic Energy Agency, provide a link to the Creative Commons license and indicate if changes were made.

 Any dispute related to the use of the works of the International Atomic Energy Agency that cannot be settled amicably shall be submitted to arbitration pursuant to the UNCITRAL rules. The use of the International Atomic Energy Agency's name for any purpose other than for attribution, and the use of the International Atomic Energy Agency's logo, shall be subject to a separate written license agreement between the International Atomic Energy Agency and the user and is not authorized as part of this CC-IGO license. Note that the link provided above includes additional terms and conditions of the license.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

## **Chapter 3 Measurement of Radioactivity**

**Viktar S. Averyn**

## **3.1 Measuring Instruments**

Three basic types of measuring instruments used for the purposes of radiation control and monitoring are spectrometers, radiometers and dosimeters (Gurachevsky 2010).

*Spectrometers* (Fig. 3.1) provide the most complete information about radiation. The most frequently used ones are spectrometers for measuring gamma-ray spectra. They are equipped with semiconductor or scintillation detectors that have highenergy resolution. The most informative part of the gamma-spectrum from the particular radionuclide is the total absorption peak. Its position is determined by the energy of gamma-radiation, and its height – by the intensity. In this manner, spectrometers are used for both qualitative and quantitative analyses of the content of the sample as they can determine not only the composition of radionuclides in the sample but also their activities. The role of processing the spectra is usually played by personal computers.

In measuring radiation from beta- and alpha-particles, because of their low penetrating power, the layer of the sample closest to the detector contributes to the detected radiation. Penetration of radiation should not be obstructed by the walls of a sample vessel placed inside the detector or because of the walls of its entrance window. This interference can be totally avoided by dissolving a sample in the liquid scintillator.

To enhance sensitivity of the measuring device, the samples are preprocessed using a thermal scavenging technique to the point of being partially ashed. Liquid samples, e.g. water or milk, are frst fltered through fbrous cationites, then dried and used as samples.

V. S. Averyn (\*)

Faculty of Biology, Francisk Skorina Gomel State University , Gomel, Belarus

<sup>©</sup> The Author(s) 2021 29

I. Naletoski et al. (eds.), *Nuclear and Radiological Emergencies in Animal Production Systems, Preparedness, Response and Recovery*, https://doi.org/10.1007/978-3-662-63021-1\_3

**Fig. 3.1** Gamma-beta spectrometer. (From: Gurachevsky 2010)

**Fig. 3.2** Gammaradiometer. (From: Gurachevsky 2010)

The most complicated spectrometers are alpha-spectrometers. Since alpharadiation has a very low penetrating ability, the measurements are typically carried out in a vacuum chamber using a semiconductor detector. Importantly, the composition of radionuclides is determined by measuring "thin" samples placed on special plates using a technique called electrode position. The total activity, on the other hand, is a much easier task, since it can be determined by measuring "thick" samples obtained through attrition and chemical or thermal concentration methods.

The main purpose of radiometers is measuring the specifc activity and activity concentration (volumetric activity) of the sources of ionizing radiation. The most commonly used are radiometers for measuring gamma-emitting radionuclides.

The simplest radiometers are able to determine activity by counting all detector pulses with the deduction of the background with account for the geometry. However, the most effcient radiometers are those with discriminative characteristics which can offer selective properties to react only to radiations emitted from a particular radionuclide. Such partition becomes possible due to the built-in electronic circuits able of selecting detector signals of certain amplitudes and a microprocessor for data processing. Modern-day radiometers, such as RKG-AT1320 (Fig. 3.2), are just like a downsized version of spectrometers.

#### 3 Measurement of Radioactivity

**Fig. 3.3** X-ray and gammaradiation dosimeter. (From: Gurachevsky 2010)

Whole-body counters (WBC), used for measuring the activity of 137Cs in a human body, can also be classifed as radiometers. A typical WBC has a chair equipped with several scintillation detectors intended for different parts of the body. Using the resulting readings, one can assess the internal radiation dose of a person. The WBC for measuring the content of strontium-90 is a considerably more complex device. There are only a few whole-body counters of that kind in the world.

*Dosimeters* (Fig. 3.3) are aimed at assessing the equivalent or effective radiation doses. The simplest devices are suited only to be able to detect photon radiations, i.e. gamma- and X-rays. A typical dosimeter is built using inexpensive Geiger-Mueller counters, the signals of which do not yield information about the photon energy. Diverse contribution into the absorbed dose made by the photons of different energy levels is taken into account by adjusting the energy response through flter compensation.

## *3.1.1 Personnel Dosimeters*

Personnel exposed to ionizing radiation are monitored to determine their occupational exposure. Although this consists primarily of monitoring external exposure, it is also necessary to assess the need to monitor internal exposure and, if necessary, incorporate it into a worker's total monitoring system. External monitoring can be accomplished by using photographic flm or thermoluminescent or pocket dosimeters (Fig. 3.4).

## **3.2 Measuring Contamination Levels in Live Farm Animals**

Animal products represent as a major contributor to the internal dose, and live monitoring of animals is an integral part of many remedial actions. Radiocaesium can be measured in live animals using a robust gamma-monitor applied to the muscle mass of a restrained animal. Live monitoring is a rapid, simple, inexpensive and effective

**Fig. 3.4** Different types of pocket dosimeters. (From: Gurachevsky 2010)

**Fig. 3.5** MKS-01 Sovetnik. (From: Gurachevsky 2010)

method of monitoring contamination for gamma-emitting radionuclides. The monitoring needs to be conducted using a robust and portable, preferably lead-shielded, NaI detector, linked to (or with integral) single or multichannel analysers (RIARAE 1993; Brynilsen and Strand 1994). In areas of elevated external dose, it may be necessary to ensure adequate shielding to attain suffciently low minimum detachable levels in the detector. Live monitoring of livestock is largely relevant for gamma-emitters, notably radiocaesium. It can be carried out on the farm and also at slaughterhouses. These measurements are performed largely before slaughtering to confrm that intervention levels are not exceeded.

Some dosimeters, e.g. a modern device MKS-АТ6130 (Fig. 3.3), can detect the fux density of beta-rays from the contaminated surface. In this mode, the flterequipped lid, hinged on special joints, is ficked open. Since the fux density measurement is typically related to radiometry objectives, such devices are called dosimeters-radiometers.

Another multipurpose instrument worth mentioning is the MKS-01 Sovetnik dosimeter-radiometer (Fig. 3.5). It uses a large-volume scintillation detector (196 cm3 ) and original algorithms of functioning and information processing.

In its dose measuring mode, Sovetnik has a signifcantly higher sensitivity as compared to more simplifed instruments, with only 2–3 s needed to reach 10% statistical error of the measurement. For this reason, the use of Sovetnik in its "dosimeter" function is very effcient in controlling the homogeneity of the produce batches. As a radiometer, Sovetnik is exceptionally convenient for measuring contamination levels in live farm animals, notably the cattle.

*Photographic flm dosimeter* is sensitive to ionizing radiation, and when it is used as a monitor, the amount of flm darkening is a measurement of radiation exposure. The flmstrip and holder constitute the flm monitor, called a *flm badge*. This flm badge has a small, open window that allows the flm to be exposed with most X-ray and gamma-radiation and high-energy beta-radiation. The flm badge also contains a set of plastic and metal flters. Since different types and energies of radiation will be attenuated differently by these flters, the pattern on the processed flm may be used to determine the type, approximate energy, and intensity of exposure. Since flm response is energy dependent, this approximate energy determination allows the use of a flm energy response calibration curve. Such monitors can be used for exposures as low as 0.01 mSv and as high as several Sv.


## **References**


The opinions expressed in this chapter are those of the author(s) and do not necessarily refect the views of the International Atomic Energy Agency, its Board of Directors, or the countries they represent.

**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 3.0 IGO license (http://creativecommons.org/licenses/by/3.0/igo/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the International Atomic Energy Agency, provide a link to the Creative Commons license and indicate if changes were made.

 Any dispute related to the use of the works of the International Atomic Energy Agency that cannot be settled amicably shall be submitted to arbitration pursuant to the UNCITRAL rules. The use of the International Atomic Energy Agency's name for any purpose other than for attribution, and the use of the International Atomic Energy Agency's logo, shall be subject to a separate written license agreement between the International Atomic Energy Agency and the user and is not authorized as part of this CC-IGO license. Note that the link provided above includes additional terms and conditions of the license.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

## **Chapter 4 Preparedness and Response to Nuclear and Radiological Emergencies in Animal Production Systems in the Context of IAEA Safety Standards**

**Kevin Kelleher**

## **4.1 Relevant IAEA Publications on Emergency Preparedness and Response for Animal Production Systems**

The IAEA has published Safety Standards and Scientifc and Technical Publications to assist in developing an adequate level of preparedness and response for a NRE and includes:


This chapter outlines how these requirements and guidelines apply to animal production systems to protect the food chain and water supply, prevent the ingestion of contaminated or potentially contaminated food and protect international trade. The generic criteria at which protective actions and other response actions to be taken in response to a NRE are described and the actions that can be implemented during each phase of any NRE for animal production systems are summarised.

The goals of emergency preparedness and response to a NRE are outlined in the IAEA's General Safety Requirements Part 7 (IAEA 2015). These goals include avoiding or minimising the occurrence of severe health effects due to chronic

K. Kelleher (\*)

Environmental Protection Agency, Dublin, Ireland e-mail: K.Kelleher@epa.ie

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radiation exposure, reducing the risk of stochastic effects (e.g. increased cancer) and mitigation of the consequences of an emergency.

## **4.2 Phases of a Nuclear or Radiological Emergency**

The arrangements, protective actions and other response actions outlined in this publication are implemented at various phases of a nuclear or radiological emergency to ensure there is adequate preparedness and response to a NRE. The stage at which the protective actions and other response actions are implemented is important to ensure their maximum effectiveness in emergency preparedness and response. Figure 4.1 outlines the various phases and exposure situations for a nuclear or radiological emergency. The phases of the emergency exposure situation are defned only for planning purposes to ensure adequate provisions are in place for an effective response in an emergency. However, during the response to a NRE, it is diffcult to clearly distinguish between these various phases, especially between the early response phase and transition phase (IAEA 2015).

## *4.2.1 The Preparedness Stage*

The preparedness stage is the stage at which adequate capabilities are in place for an effective emergency response in a nuclear or radiological emergency. This capability consists of a set of elements that include but are not limited to:


**Fig. 4.1** Temporal sequence of the various phases and exposure situations for a nuclear or radiological emergency (IAEA 2018a)

This is the time to ensure an emergency management system is established and maintained and that roles and responsibilities for preparedness and response for a nuclear or radiological emergency are clearly specifed and clearly assigned. This can be achieved through the fulflment of various requirements outlined in the IAEA GSR Part 7 (IAEA 2015).

#### **4.2.1.1 Hazard Assessment**

Requirement 4 of GSR Part 7 (IAEA 2015) requires that a hazard assessment is conducted to provide a graded approach to a nuclear or radiological emergency. The purpose of the hazard assessment is to identify facilities, activities or sources that would require appropriate response actions in the event of an emergency. These facilities are grouped based on their threat level and their potential consequences from Categories I to V (IAEA 2015). For animal production systems, the categories of primary concern are:


These are typically nuclear power plants, research reactors and nuclear-powered vessels.1 A severe accident at Category I or Category II facilities can result in the distribution of radioactivity over a wide geographical area, leading to contamination of the environment and subsequent contamination of the food chain. For example, the Chernobyl and Fukushima Daiichi accidents are Category I facilities that gave rise radioactive contamination of the environment and food. Hazard assessments should be conducted periodically and bring together information at a national, regional, local and, where appropriate, international level. The results of hazard assessment should be coordinated and shared at a national level with representatives of all organisations that have a role in response to a nuclear or radiological emergency. This is to ensure that all governmental bodies and organisations, including those responsible for agriculture and food production, are in engaged in the hazard analysis.

<sup>1</sup>Category III facilities are those that would not warrant actions off-site, for example, industrial irradiation facilities or hospitals.

Category IV are activities or acts that are at an unspecifed location, for example, the transport of nuclear or radioactive material.

#### **4.2.1.2 Development, Justifcation and Optimisation of a Protection Strategy**

A protection strategy is developed, justifed and optimised based on the hazards identifed and on the potential consequences of a nuclear or radiological emergency. Optimisation of the protection strategy can be assisted with the setting of generic criteria. The generic criteria are typically expressed in terms of the dose to humans that would be received if no actions were taken (projected dose) or dose that has been received. The generic criteria are within a range of 20–100 mSv (IAEA 2015) and are set at these levels to avoid the occurrence of severe health effects due to radiation exposure and to reduce the risk of stochastic effects. If the generic criteria are exceeded, protective actions and other response actions are implemented. Table 4.1 outlines the generic criteria for protective actions and other response

**Table 4.1** Generic criteria for protective actions and other response actions for food, milk and drinking water to reduce the risk of stochastic effects through the ingestion of contaminated food, milk or drinking water (IAEA 2015)


actions related to food, milk, drinking water and nonfood commodities such as animal feed in an emergency to reduce the risk of stochastic effects.

Generic criteria are based on doses that need to be determined in the preparedness phase taking into account a large number of factors (IAEA 2015). The generic criteria can contain considerable uncertainties; therefore, they cannot be used directly in emergency response where urgent actions are required. Instead a set of operational criteria are derived, in advance, from the generic criteria that can be used directly in an emergency to allow the effective implementation of protective actions including food milk and drinking water restrictions and their associated arrangements. The operational criteria are:


The relationship between generic criteria and operational criteria are outlined in Fig. 4.2.

**Fig. 4.2** The system of generic criteria and operational criteria


**Table 4.2** Codex guideline levels for radionuclides in foods with contamination following a nuclear or radiological emergency for use in international trade (CODEX STAN 2006)

#### **4.2.1.3 International Trade of Food Following a Nuclear or Radiological Emergency**

The trade of food internationally following a nuclear or radiological emergency is governed by the Joint FAO/WHO Codex Alimentarius Commission Guidelines for radionuclides in food (CODEX STAN 2006). Similar to the generic criteria for the restriction of food traded internationally outlined in Table 4.1, the guideline levels are based on a reference level of 1 mSv per year. Assuming 10% of the diet consumed is from imported food, guideline values have been determined for 20 radionuclides for infant foods and other foods other than infant foods. The 20 radionuclides have been divided into four groups based on their radiotoxicity and are outlined in Table 4.2. If food traded internationally are below the guideline levels, then they are deemed safe for human consumption. As these values are only guideline levels, if they are exceeded, national governments will need to determine whether these foods can be traded and consumed within their jurisdiction.

#### **4.2.1.4 OILs for Triggering Food, Milk and Drinking Water Restrictions**

The IAEA have derived default OILs for use in a nuclear or radiological emergency based on generic criteria (IAEA 2011). Default OIL values need to be established in the preparedness phase in order to make decisions quickly in the urgent and early phases of an emergency when information is limited.

In the early phase of an emergency, surface contamination measurements are relatively easy to obtain using feld survey instruments. OIL 1, OIL 2 and OIL 3 are measurements of ground contamination calling for urgent protective actions, early protective actions and restrictions to be implemented to keep the dose to any person below the generic criteria (for examples of generic criteria, see Table 4.1). This includes the implementation of the appropriate restrictions on food, milk and


**Table 4.3** Default OILs for deposition (IAEA 2011)

drinking water. Table 4.3 outlines the default OILs for ground/surface contamination and the response action for food, milk and drinking water if the OIL is exceeded.

If ground/surface contamination measurements indicate the exceedance of generic criteria, food, milk and drinking water, restrictions may be put in place. Further analysis will be required to confrm or lift these restrictions. This requires the analysis of food, milk and drinking water samples. OIL 5 is a screening of potentially contaminated foodstuffs for gross alpha and beta activity. If the gross alpha and beta screening levels are below the OIL 5 values, then the foodstuff is safe to consume in the emergency phase. If the screening level is exceeded, then additional analysis is required to determine the radionuclide-specifc concentrations in the food, milk or drinking water; this analysis is based on the use of OIL 6. The collection and analysis of food, milk and drinking water sample analysis of specifc radionuclides and comparison with their corresponding OIL 6 values are very time-consuming and complex. Comprehensive activity concentrations in


**Table 4.4** Default OILS for contamination of food milk and drinking water (IAEA 2011)

food, milk and drinking water may not be readily available in the timeframes required for effective decision-making in the early stages of an emergency. Therefore, the IAEA has defned an additional OIL 7 but for light water reactor emergencies only (IAEA 2013a) (Table 4.3). The OIL 7 values are defned through 131I and 137Cs as marker radionuclides (but they consider all other radionuclides that are likely to be discharged as a result of an emergency at a light water reactor).

Table 4.4 outlines the default OILs for food milk and water along with the response action if the OIL is exceeded.

Restrictions on food, milk and drinking water can be implemented based on generic criteria or OILs only if they are non-essential and there are alternative sources of food, milk or drinking water available. These restrictions cannot be implemented if they would result in severe malnutrition, dehydration or other severe health impacts (IAEA 2015).

For nonfood commodities, for example, animal feed response actions such as restrictions on its use or trade can be developed using OILC values. Methods for the derivation of OILC values are outlined in IAEA GSG-11 (IAEA 2018a).


**Table 4.5** Suggested sizes for emergency zones and distances for light water reactors (IAEA 2013a)

#### **4.2.1.5 Emergency Planning Zones and Emergency Planning Distances**

In accordance with the development of a protection strategy as outlined in IAEA's GSR Part 7 (IAEA 2015), arrangements need to be made in the preparedness stage to ensure effective decision-making in the taking of urgent protective actions, early protective actions and other response actions. Given the limitations on the information available in the urgent and early phases of an emergency, the response actions are assisted through the establishment of specifc off-site emergency planning zones and emergency planning distances (IAEA 2007a). These emergency planning zones and distances are applicable to facilities in Emergency Preparedness Categories I and II and in areas in Emergency Preparedness Category V.

The emergency planning zones and distances include a precautionary action zone (PAZ), an urgent protective action planning zone (UPZ), an extended planning distance (EPD) and an ingestion and commodities planning distance (ICPD). These zones and distances range from a few up to hundreds of kilometres and are contiguous across country borders. Table 4.5 outlines the suggested sizes for the emergency planning zones and emergency planning distances for light water reactors, based on their power levels, but the actual boundaries of these need to be defned by local conditions and landmarks (e.g. roads and rivers) so that they are easily identifed during an emergency. An example of these zones and distances for light water reactors can be seen in Fig. 4.3 (IAEA 2013a).

## *4.2.2 Emergency Exposure Situation*

A nuclear or radiological emergency can be declared as a result of an actual or potential release of radioactivity.

Once a nuclear or radiological emergency has been declared, prompt action is required during the emergency exposure situation. The emergency exposure situation can be divided into three phases as outlined in Fig. 4.1. The timeline of these phases is dependent on the nature and scale of the nuclear or radiological emergency. The sequence of protective actions as a result of a nuclear or radiological emergency is outlined in Fig. 4.4.

**Fig. 4.4** Temporal sequence of various types of protective actions and recovery options for a nuclear or radiological emergency (IAEA 2018a)

#### **4.2.2.1 The Urgent Response Phase**

The urgent response phase is the period in which actions must be taken within hours or days to be effective; these are the precautionary and urgent protective actions that have been predetermined in the preparedness phase and are based on observables and conditions at a facility (e.g. the declaration of a general emergency).

Precautionary urgent protective actions are implemented before or shortly after a release of radioactive material to avoid severe deterministic effects. For Category I facilities, the precautionary urgent protective actions include the consumption of an ITB agent, the safe evacuation of the PAZ beyond the UPZ and food, milk and drinking water restrictions. These precautionary urgent protective actions should take place within an hour of the declaration of a general emergency (IAEA 2013a).

Urgent protective actions need to be implemented within hours or days of the declaration of an emergency to maximise their effectiveness. These actions include evacuation, short-term sheltering, actions to reduce inadvertent ingestion, decontamination of individuals and protection of the food and water supplies, restrictions on signifcantly contaminated food and water supplies and the provision of instructions to protect agricultural products. These urgent protective actions are implemented within the predetermined emergency planning zones and distances.

Within the UPZ, urgent protective actions can include sheltering or evacuation, administering of ITB agents, actions to reduce inadvertent ingestion and instructions to the public not to consume food that may have been directly contaminated or to consume milk from animals that may graze on contaminated ground.

The principle urgent protective action within the EPD is to take actions to reduce inadvertent ingestion by keeping hands away from the mouth, not to drink, eat or smoke until hands are washed, and to avoid activities that could result in the creation of dust that could be ingested.

The urgent protective actions within the ICPD are to place grazing animals on protected feed if feasible, to protect food and drinking water sources and to stop the consumption and distribution of non-essential local produce, wild-grown produce, milk from grazing animals and animal feed until the levels of contamination have been assessed.

Environmental monitoring should also begin as soon as practicable to implement the appropriate restrictions on food and drinking water from rainwater where they may be contaminated to levels requiring restrictions. In practice, it may only be feasible to conduct ground/surface monitoring in the PAZ and UPZ to determine whether OIL 3 has been exceeded and food restrictions are required. Further and more comprehensive environmental monitoring will be required during the subsequent phases of the emergency.

Following the declaration of an emergency, specifc urgent protective actions can be implemented before and shortly after the release of radioactivity to the environment to reduce the risk of contamination of animals. Such actions include (Nisbet et al. 2015):


These urgent protective actions are applicable for areas in threat Categories I, II and V.

#### **4.2.2.2 The Early Response Phase**

At the early response phase, the radiological situation has been suffciently characterised to enable the implementation of actions that are effective within days or weeks; these are the early protective actions.

Early protective actions are those pre-established in the preparedness phase and are based on operational criteria, such as OILs, until more detailed characterisation of radioactivity in the environment and laboratory analysis of food, milk and water samples are conducted in the transition phase.

The environmental monitoring, sampling and laboratory analysis can be used to start adjusting the initial protective actions implemented in the urgent response phase to confrm the adequacy of the controls in place, to provide for additional protective actions or to remove restrictions. This could lead to:


There may also be a need to revise the OIL values and to extend monitoring and assessment beyond the initial emergency planning zones and distances to take into account the conditions during the emergency. This could lead to additional restrictions or the lifting of restrictions on food, milk and drinking water in certain areas.

Consideration also needs to be given to the protection of international trade and commercial interests, and restrictions can be placed on food and commodities from affected areas until it has been verifed that they do not exceed internationally agreed criteria for trade (IAEA 2013b).

The early response phase is the time where other agricultural countermeasures can begin to be implemented in order to protect the food chain and to avert dose over longer time periods. In addition to the early protective actions listed above, the other protective actions considered most effective for animal production systems in the early phase are (Nisbet et al. 2015):


#### **4.2.2.3 The Transition Phase**

The transition phase commences once the radioactive source is under control, the situation is stable and the radiological situation is well understood. Once this occurs there is a progression to the point at which the emergency can be terminated through the reduction of long-term exposures and the improvement of living conditions in the affected areas (IAEA 2018a).

At this phase of the emergency the actions implemented are, in a large part, remedial or recovery actions as the more disruptive protective actions have been implemented in the urgent and early response phases. Furthermore, the actions in the transition phase are not driven by urgency and can be justifed and optimised through consultation with interested parties, whereas in the earlier phases of an emergency, consultation with interested parties is limited.

A number of aspects need to be considered at the preparedness phase when establishing arrangements for the transition phase. Three key elements to be considered for animal production systems are:


The protective actions that were implemented in the urgent and early response phases are based on operational criteria that were predetermined in the emergency preparedness phase and on the limited environmental monitoring that is conducted in the early response phase.

OILs can be used to consider which specifc protective actions can be lifted or adapted. For example, restrictions on food, milk and drinking water in the urgent and early response phases were based on EALs and OIL3. OIL 5, OIL 6 and/or OIL 7 can be used to adjust any restrictions imposed. In the transition phase, a comprehensive sampling and monitoring programme is carried out to determine the levels of radioactivity in the environment and in food, milk and drinking water. This detailed radiological characterisation can be used to determine the dose in the future after protective actions have been lifted, i.e. the residual dose. The residual dose can be determined once the exposure pathways have been characterised and the urgent and early protective actions are known.

The fnal decision on the adapting or lifting protective actions are based on these residual dose assessments. In order to terminate an emergency, the residual dose should be in the order of 20 mSv effective dose in a year (IAEA 2015). In the transition phase, after more comprehensive sampling and monitoring of food, milk and drinking water, the actual dose from ingestion can be calculated, and its contribution to the residual dose can be estimated to determine whether this protective action can be adapted or lifted (IAEA 2018a).

The lifting or adapting of protective actions may also be possible through the implementation of decontamination and dose reduction techniques. In animal production systems, the techniques that can be used in the transition phase for dose reduction are (Nisbet et al. 2015):


#### **4.2.2.4 Radioactive Waste Management**

The management of radioactive waste increases in importance in the transition phase of an emergency response as, earlier in an emergency, the focus is primarily on implementing protective actions. Large-scale nuclear or radiological emergencies can generate large volumes of radioactive waste capable of overwhelming national capabilities for radioactive waste management and delaying the termination of an emergency. The waste generated during a nuclear or radiological emergency can be as a result of the emergency situation or could arise from the protective actions or other response actions implemented during the emergency (IAEA 1987, 2013b).

Before the disposal of any waste arising from a nuclear or radiological emergency, it needs to be identifed, characterised and categorised taking into account the various radiological and non-radiological (chemical, biological, physical and mechanical) aspects of the waste. This should be based on regulations on radioactive waste management that should be developed in the preparedness phase. Methodologies also need to be developed in advance for the identifcation of appropriate storage options and sites and the predisposal management of radioactive waste through segregation, packing, transport and storage. Arrangements should also be made to minimise the amount of waste declared as radioactive waste through the introduction of clearance levels for waste materials or through the reuse or recycling of the waste.

Consideration should also be given to obtain international assistance in waste management.

In animal production systems, the management of animal remains also needs to be given special consideration. For animal production systems, management options need to be identifed for the disposal of animal carcasses. Workers handling the animal carcasses need to be trained in basic radiation protection principles, and they need to be provided with the appropriate equipment to ensure their exposure to radioactivity is kept to a minimum (IAEA 2013b).

The disposal options that can be considered in the transition phase include (Nisbet et al. 2015):


#### **4.2.2.5 Dealing with Non-radiological Consequences**

In the early stages of emergency response, the radiological issues typically outweigh non-radiological consequences, but in the transition phase, as doses tend to decrease with the effective implementation of protective and recovery actions, nonradiological factors become increasingly important. These non-radiological consequences include psychosocial, economic and political factors and require the active participation of the public and other interested parties in the transition phase. This can include the psychosocial impact of farm and veterinary workers in areas affected by radioactive contamination. For example, farmers concern about growing or selling produce (Takebayahi et al. 2017).

A nuclear or radiological emergency and the protective actions implemented in the emergency response phase can have a detrimental impact on the economy, trade and people's livelihood. Therefore, compensation for the damage caused by nuclear or radiological emergencies may be required in these instances. This was demonstrated in the United Kingdom in the wake of the Chernobyl accident in 1986 where farmers where compensated for market losses incurred on sheep sold at auction (Kerr and Mooney 1988; IAEA 2018a).

## *4.2.3 The Termination of a Nuclear or Radiological Emergency*

The termination of a nuclear or radiological emergency is based on a formal decision that is made public and is made in consultation with interested parties. The termination of the emergency takes into consideration both radiological and nonradiological consequences and can be implemented at different times and in different geographical areas depending on the nature and scale of the emergency (IAEA 2015).

A nuclear or radiological emergency can only be terminated once a number of general and specifc prerequisites have been met. The source of the nuclear or radiological emergency should be under control, the future development of the situation is well understood and no further signifcant releases or exposures should be expected. All of the urgent and early protective actions should be implemented, with the possibility that some may already be lifted or adapted, and the radiological situation should be well characterised with doses assessed for the affected populations. This includes the dose ingested through the consumption of food from animal production systems. The radiological situation should be assessed against the appropriate reference levels, generic criteria and operational criteria to determine whether the residual dose of the affected population is at or below approximately 20 mSv per year (IAEA 2018a).

Once all the prerequisites for the termination of an emergency have been met, the emergency exposure situation ends, and the end of the emergency can be declared.

## *4.2.4 Planned or Existing Exposure Situation*

Once the emergency has been terminated the situation moves to either a planned or existing exposure situation (Fig. 4.1).

Nuclear or radiological emergencies that do not result in a signifcant release of radioactivity into the environment and do not result in long-term exposure of individuals due to residual radioactive material can transition to a planned exposure situation. In these circumstances, these situations are not expected to result in an exposure situation that differs from one that existed prior to the emergency (IAEA 2018a).

An emergency that has resulted in a signifcant release of radioactive material to the environment, typically a nuclear emergency, will result in exposure during the emergency and in the long term due to residual radioactivity in the environment. For these situations, once the end of an emergency has been declared, the situation transitions to an existing exposure situation (IAEA 1987, 2013b, 2018a).

The IAEA requirements and guidance for planned and existing exposure situations are governed by additional IAEA safety standards series publications and include but not limited:


#### **4.2.4.1 Restrictions on Food, Milk and Drinking Water After the Termination of an Emergency**

Once the end of an emergency has been declared, any restrictions implemented on food, milk or drinking water are no longer governed by the requirements for emergency exposure situations (IAEA 2016). Instead, for existing exposure situations, the framework is governed by the WHO Guidelines for Drinking-Water Quality (WHO 2011) and the IAEA GSR Part 3 (IAEA 2013c). The WHO Guidelines for drinking water quality sets a reference level of 0.1 mSv per year for consumption of drinking water from all sources of radioactivity. Requirement 51 of GSR Part 3 requires regulatory bodies to establish reference levels for exposure due to food, feed and drinking water based on a dose that doesn't exceed a value of about 1 mSv per year.

For food used in international trade, the Codex Alimentarius guidelines outlined above still apply in an existing exposure situation (CODEX STAN 2006).

Following any nuclear or radiological emergency, it is important that arrangements remain in place to reassure the public and interested parties (such as trading partners) that the food meets international standards. This can be achieved through a testing and certifcation system that can verify that food products are safe and do not exceed the reference levels and internationally agreed criteria for trade (IAEA 2013a).

## **References**


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## **Chapter 5 Environmental Pathways of Radionuclides to Animal Products in Different Farming and Harvesting Systems**

**Brenda Howard**

This chapter briefy describes the NREs which released large amounts of radionuclides that had the potential to cause signifcant contamination of animals and animal products. It then describes the key environmental and metabolic pathways of animals and animal product contamination. The different methods used to quantify the transfer of radionuclides between relevant environmental pathways are also described. Radionuclide-specifc information is provided in subsequent sections. Observed effects on agricultural and game animals after two NREs are also described.

## **5.1 Major Nuclear or Radiological Emergencies Causing Animal and Animal Product Contamination**

There have been a range of different NREs that have contaminated animal and animal products. Animal products have been contaminated after all of the four largest NREs that have occurred from nuclear reactors or waste storage facilities. Estimated radionuclide releases from these four sources are listed in Table 5.1. Most of the radionuclides listed in Table 5.1 may be important contributors to internal exposure to humans via animal products after a NRE.

Although many different radionuclides can be released following a NRE, some are short-lived, and others do not readily transfer into food. Additional radionuclides, not listed above, of potential relevance for animal products after NREs include 3 H, 14C, 35S, 60Co, 95Nb, 99Tc, 103Ru, 106Ru, 110Ag, 129I, 132Te, 192Ir, 235U and 241Am. The relative importance of these different radionuclides varies depending on the magnitude of the release and on environmental and agricultural husbandry

B. Howard (\*)

School of Biosciences, Nottingham University, Nottingham, UK

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**Table 5.1** Estimated releases of selected radioisotopes for the four largest NREs which led to animal product contamination

a Pu alpha

b 241Pu

characteristics. For animals and animal products, it also depends heavily on the extent to which the radioisotopes are accumulated by animal tissues – this issue is addressed in Sect. 5.4.3.

Examples of the features controlling the contamination of animal products and their consequences are given in this chapter based on information acquired after each of the four NREs.

## **5.2 Key Environmental Processes Controlling Animal Product Contamination**

There are a large number of different environmental factors which affect the extent to which radionuclides, such as those listed in Table 5.1, will accumulate in animals and animal products in the human food chain. Some factors are more important in the emergency phase after a NRE whilst others are more relevant in the transition to recovery phases.

They include:


Some of these processes are highly dependent on which radionuclides have been released (such as soil fxation and gut absorption), whereas others are not (such as interception and human dietary preferences).

There are defnable situations where there is substantial transfer of radionuclides into food products caused by particular features of the release or the contaminated system. In such situations, the feature is considered to be radioecologically sensitive to that radionuclide (Howard 2000). A typical example is the presence of certain soil types which fail to permanently fx radiocaesium ions to soil particles, thereby allowing continued transfer into the soil solution and subsequent uptake by plants and then animals (Fig. 5.1).

Milk and meat products can become contaminated rapidly, especially if radionuclides are released to the atmosphere. Radionuclides in milk can be a major source of internal dose via the human food chain soon after a release. Radioiodine (especially 131I), radiocaesium (134Cs and 137Cs) and 90Sr are often key components of ingestion dose via animal products, potentially over decades for 137Cs and 90Sr. The radioactive contamination of animals and animal products impacts not only on farmers and consumers but also on agricultural and regulatory ministries and the

**Fig. 5.1** Routes of radionuclide transfer in the environment (IAEA 2006a)

food industry. Professional groups that may be involved in the response to a NRE need to be informed about how animal products become contaminated and what controls the extent to which major radionuclides will be retained in, or lost from, animal tissues.

There are a number of different routes through which agricultural, free-ranging domesticated animals and game animals may become contaminated with radionuclides released from NREs. The key routes of contamination are:


The relative importance of the above routes of contamination of animal products in the human food chain depends on the environmental pathways. The importance of these pathways depends on many factors such as the time of year that the NRE happened, the radionuclides released and the prevailing animal production or harvesting practices in affected areas.

Other characteristics that affect the extent of radionuclide contamination of animal products include the characteristics of the land used for production (such as the soil type and plant uptake rates), the extent of gastrointestinal absorption, the metabolic fate in the animal and the rate of loss from tissues (principally in urine, faeces and milk). These pathways are described in more detail below, focusing on aspects relating to the human food chain.

## *5.2.1 Vegetation Interception*

The interception and retention of radionuclides by plants which are then consumed by grazing or browsing animals is a key process in the emergency phase after a NRE. It provides a fast and effective route for initial transfer of recently deposited radionuclides to animal products.

Once radionuclides are released into the air (or to water), various physical and chemical processes infuence the extent to which they are transported and dispersed in the environment. The physical and chemical forms of the radionuclide, and the turbulence of the receiving medium (such as air movements and water fow), play an important role during the initial phase.

Other processes affect the transfer of radionuclides from the air (or the water column) to the receiving surface. Potential deposition mechanisms include:


Radionuclides interact with solid materials such as soil particles and sediments in many different ways including electrostatic attraction and the formation of chemical bonds. The radionuclide activity concentration per unit mass of solid is affected by the surface area available for adsorption per unit mass or volume and is, therefore, greater for smaller objects. In terrestrial areas, the interception of radionuclides by vegetation occurs for both wet and dry deposition.

*Wet deposition* occurs when radionuclides in air are washed out by precipitation. Vegetation surfaces retain a fraction of radionuclides deposited with the rain, with the remaining fractions falling onto the ground. The fraction of radionuclides in the air that is initially intercepted is an important quantity in radioecological models because direct deposition can lead to relatively high activity concentrations in pasture grazed by animals, and other feed crops.

Plants with a relatively high biomass per unit area will intercept more radionuclides in wet deposition, associated with a higher interception fraction. Other factors such as the capacity of the canopy to retain water, ionic form of the radionuclide, precipitation amount and intensity, vegetation maturity and leaf area index (LAI – upper-side green leaf area per unit ground surface area) can all infuence the extent of interception of wet deposition (IAEA 2009). For example, the interception fraction of 137Cs by grass was reported to decline with increasing intensity of rainfall from 0.1 to 0.2 for low rates of up to 1 mm of rainfall to an order of magnitude lower at higher rates of 11 mm of rainfall (Kinnersley et al. 1997).

Most of the intercepted radionuclides are gradually transferred to the soil and are only temporarily present on the surface of the vegetation. Radionuclide activity concentrations on vegetation may be reduced by various physical processes, including wash-off by rain or irrigation, surface abrasion, leaf bending from wind action, resuspension, tissue senescence, leaf fall, herbivore grazing, growth and evaporation.

Interception and retention of radionuclides on plant surfaces is a critical process in the emergency phase after a NRE. If a NRE occurs before the growing season, the likely transfer of radionuclides to grazing animals will be low, but may still occur if stored feed is not covered or animals are kept outdoors. Conversely, a NRE occurring at the height of the growing season with light rainfall when plant biomass is high and animals are outside grazing pasture may present an immediate problem to responding authorities. After the Chernobyl NRE, dairy cows in affected areas of the USSR were grazing pasture which had suffcient leaf mass in late April and early May to intercept signifcant amounts of radioiodine and radiocaesium.

*Dry deposition* is dependent on the characteristics of the intercepting surface, usually quantifed using the surface roughness (Heinemann and Vogt 1980), which generally increases as the plant canopy develops. The extent of interception for dry deposition depends on the standing biomass of plants, the chemical form and the particle size of the deposit. Interception is similar for small (up to a few micrometres diameter) particles, but as particle size increases, interception decreases probably because larger particles roll off the plant surface more easily than smaller ones. Furthermore, if vegetation is moist or wet, absorption increases possibly due to an enhanced stickiness. Particles with a diameter up to a few micrometres are relatively more important because larger particles from a radioactive cloud are rapidly depleted. As for wet deposits, the extent of interception of dry deposits depends on many factors including plant yield, particle size, the crop, the chemical form and whether the receiving surface characteristics are wet or dry.

Although relatively minor in comparison to the above routes, stored crops intended as fodder for animals may become contaminated by surface deposits of radionuclides if they are not covered outdoors.

Information is available on how to quantify interception in IAEA documents TECDOC 1616 and TRS 472 (IAEA 2009, 2010).

## *5.2.2 Chemical Form of the Released Radionuclides*

The chemical form of the released radionuclides impacts on many different pathways, including the extent of interception, the rate at which radionuclides are released into the soil solution and are then available for plant uptake and the ability of the radionuclide to be absorbed in the animal's GI tract. Examples of the impact of chemical form will be given in the relevant sections below.

## *5.2.3 Radionuclide Behaviour in Soils*

Plants take up nutrients and pollutants from the soil solution, so the radionuclide activity concentration in soil solution is a critical determining factor for plant uptake. The activity concentration of radionuclides in soil solution is determined by processes infuencing the loss of radionuclides that are adsorbed onto soil components that move into the soil solution usually by competitive ion exchange (quantifed as the cation exchange capacity). The concentration and composition of other elements present in the soil are important in determining radionuclide distribution between soil and soil solution. The amount and nature of clay minerals in soils and the concentrations of competitive major cations are often key factors in determining exchange mechanisms in soils of radionuclides, but other factors, such as microbial activity, may also affect radionuclide mobility.

In the emergency and transition phases of a NRE, radionuclide movement into the soil solution may be relatively high, leading to high initial contamination of plants via root uptake. With time the availability of radionuclides in soil solution tends to reduce as radionuclides gradually adsorb to soil components. The rate of reduction varies with radionuclide and soil type.

Vertical migration of radionuclides down the soil column arises from various transport mechanisms including convection, dispersion, diffusion and biological mixing. Radionuclides can also migrate to deeper soil layers at faster rates when there is a high amount of rainfall over a short period of time, especially if there are surface cracks in dry soil or when soils contain a relatively large proportion of sand particles. Soil-dwelling animals can also relocate material both laterally and vertically during the construction of burrows, tunnels and chambers, and the roots of plants can cause a similar effect.

Large-scale lateral migration of radionuclides can also occur in catchments and is often associated with soil erosion or heavy rainfall events such as typhoons. The distribution of radionuclides in sediment or soil layers of the foodplain can be considerably altered by such events.

A high rate of radionuclide vertical migration in soil matter may be benefcial as it will remove radionuclides out of the rooting zone, thereby reducing external doses and plant uptake for surface routing species. However, for many undisturbed soils, most of the deposited radiocaesium is retained in the upper 10 cm layer.

## *5.2.4 Radionuclide Transfer from Soil to Crops*

The uptake of radionuclides, as for other trace elements by plant roots, is a competitive physiological process (IAEA 2010). The processes infuencing radionuclide transport from soil to plants vary with both radionuclide and soil type. The fraction of deposited radionuclides taken up by plant roots can differ by orders of magnitude between different elements and between different physico-chemical forms of the same radionuclide. There are also differences in radionuclide uptake between plant species growing on the same soil type.

There will probably be a decrease with time in the activity concentrations of most radionuclides in plants after a short-duration release of radionuclides into the environment due to the gradual fxation by soils (and sediments) discussed above.

After the initial emergency exposure situation of a few months to a year, the dominant processes determining radionuclide movement in farming systems change. The extent to which radionuclides transfer from soil into agricultural products during the later planned or existing exposure situation depends not only on the density of contamination but also on soil type, moisture regime, texture, agrochemical properties and the plant species. The impact of differing radioecological sensitivities of soils is often more important in explaining spatial variation in transfer of radionuclides in agricultural systems. Therefore, identifcation of radioecologically sensitive areas for animals and animal products is based on both the deposition density of different radionuclides and their mobility within different types of soil.

In terrestrial systems, wind action and rain "splash" on the soil can reintroduce radionuclides to the air where they can be ingested (if deposited on vegetation

surfaces) or inhaled by animals. Such resuspension and soil adhesion are infuenced by the height and type of the plant canopy as well as weather (wind, rain), soil type and animal trampling. Grazed plants are likely to include radionuclides associated with soil adhered to the plant, as well as being incorporated within the plant itself. For radionuclides with a low transfer from soil to plant, the soil adhered on the surface of pasture grass may be the major source of radionuclide ingested by grazing ruminants. For example, root uptake of plutonium is negligible compared to direct contamination of leaves via adhered soil from rain splash or resuspension, so most ingested plutonium will be associated with adhered soil, especially for pastures with a low plant biomass.

## *5.2.5 Quantifcation of Radionuclide Transfer to Plants and Fodder Crops*

The transfer from soil to plants is commonly quantifed using the concentration ratio (CR) (also called a transfer factor (TF)), which is equal to the plant mass activity concentration (often in Bq/kg dw), divided by soil activity concentration, Bq/kg (dw). Available CR transfer parameter values for a wide range of radionuclides and crops for different soil types are available free in the downloadable TECDOC 1616 (IAEA 2009) and TRS 472 (IAEA 2010).

## *5.2.6 Intake and Absorption of Radionuclides by Animals*

The transfer of radionuclides from plants (and soil) to herbivores occurs mainly by ingestion, although uptake via water can contribute to intake in the emergency phase if water sources have become contaminated after the deposition of radionuclides.

Animal products can be contaminated within a few hours of radionuclide release, mainly by the consumption of contaminated food and, to a lesser extent, water. Contamination through the skin is infrequent and absorption by inhalation is marginal for most radionuclides. The most radioecologically sensitive scenario is that of animals grazing outdoors that are directly consuming contaminated plants which have intercepted radionuclides on their surfaces.

For radionuclides that are not readily taken up by plants, soil adhesion can represent the most important route of intake especially since topsoil tends to be much more contaminated than plant material (IAEA 1994). In some instances, soil ingestion by animals may be deliberate (e.g. to obtain essential minerals), but soil can also be ingested by licking or preening of fur, feathers or offspring (Whicker and Schultz 1982). Radionuclides that are adsorbed to soil matrices may be less bioavailable than when incorporated into plant material for transfer into animal products.

Animals that are housed in pens and barns and given previously stored food (as long as that is protected from fallout) will not be signifcantly affected although the source of water would need to be identifed. Surface water systems can be initially directly contaminated by deposited radionuclides, but dilution in water bodies normally greatly reduces the radionuclide activity concentrations in water.

## *5.2.7 Gastrointestinal Absorption*

Absorption of radionuclides from the gastrointestinal tract (GI tract) of animals depends on, amongst other factors, the physico-chemical form of the radionuclide, the composition of the feed and the nutritional status of the animal.

Although absorption can occur through the skin and lungs, oral ingestion of radionuclides in feed, and subsequent absorption through the GI tract, is the major route of entry of radionuclides. The absorbed fraction (Fa) is defned as the fraction of that ingested by animals that is transferred through the GI tract and is a key factor determining the extent of radionuclide contamination of animal tissues and milk. The absorbed fraction depends on many different factors including metabolic status (e.g. age, lactation state, physiological condition), chemical and physical speciation of the radionuclide and the presence of competing ions.

The method of determination of GI tract absorption is important. An apparent absorption is derived from information on the whole-body intake and excretion of the radionuclide. A true absorption value is measured in a metabolic study that involves injection of a tracer which enables determination of endogenous faecal excretion (i.e. direct transfer from blood to the intestine). Endogenous secretion from tissues into the gut occurs for the key radionuclide, radiocaesium, so it is important to distinguish whether reported values refer to an apparent or true absorption value.

Available information on the fractional absorption values for radionuclides in ruminants is available in the TECDOC 1616 and TRS 472 (IAEA 2009, 2010). Fractional absorption values for the most well-studied radionuclide elements are given in Table 5.2. The number of data available on Fa in ruminants for different radionuclides varies, and, therefore, so does the confdence attributable to each


**Table 5.2** Range in fractional GI tract absorption values (Fa) for different elements in domestic ruminants

Howard et al. (2016a)



ICRP (2006)

value. The Fa values vary from almost negligible, in the case of actinides such as plutonium, to 100% for radioiodine (Howard et al. 2009a, 2016a). Data on Fa for iodine, caesium and strontium are considered in more detail in Sect. 6.4.

The compiled ruminant Fa values for radionuclides or stable elements are similar to those reported by the International Commission on Radiological Protection (ICRP) shown in Table 5.3 for humans (and relevant for other monogastric animals such as pigs). Therefore, if ruminant-specifc Fa values are not available, those given for humans may be used instead.

After absorption, radionuclides circulate in the blood to different tissues as discussed below.

## *5.2.8 Quantifcation of Radionuclide Transfer to Animal Products*

To quantify the transfer of radionuclides to milk and meat, two types of parameter values are commonly used: transfer coeffcients (*Fm* for milk and *Ff* for other tissues) and concentration ratios (CR) as follows:

Transfer coeffcient (d/kg or d/L)

$$F\_m \text{ or } F\_f = \frac{\text{Equilibrium activity concentration in food product} \left( Bq/\lg f \text{\#} \right)}{\text{Daily intake of radionucible} \left( Bq/\text{d} \right)}$$

Concentration ratio

$$CR = \frac{\text{Equilibrium activity concentration in food product} \left( Bq/kg \, f \% \right)}{\text{Radionuclide activity concentration in feed} \left( Bq/kg \, dw \right)}$$

Transfer coeffcient values can be derived by dividing a CR value by the daily dietary intake (in kg/d), and, conversely, CR values can be derived by multiplying the transfer coeffcient value by the daily dietary intake (in kg/d). Over the last 40 years following the introduction of the transfer coeffcient concept, many studies have been conducted to determine values for a range of radionuclide – animal product combinations.

To accurately estimate intake, both the dietary composition and relative contamination of each component (in *Bq*/kg dw) need to be quantifed. Estimates of the feed intake of animals are more accurate in experimental studies under controlled conditions, whereas in feld studies the intake is often not measured, which can lead to variability in reported *Ff* and *Fm* values.

The typical diet of agricultural animals varies between and within countries, and with the season according to feeding regimes (including whether the animals graze outdoors or are kept indoors), and is related to live weight, maintenance requirements and milk production rates. Regional data on animal nutrition requirements relevant to the region and farming system being considered can be used to derive dietary intake information. Preferably feed intake estimates would either be based on agricultural production criteria or acquired directly from the farming community. Grassy vegetation tends to be much more highly contaminated than other components of the diet, so all radionuclide intake can be assumed to come from this part of the diet when animals are consuming grass-based fodder. In published international cow milk datasets, some Fm and Ff values are based on estimated daily dry matter intake (DMI) many of which are best estimates or recommended values that do not take account of changes in the factors discussed above. Although the lack of measured daily DMI introduces uncertainty, it is unlikely to change derived Fm values by more than a factor of 3.

Transfer coeffcients of radionuclides to milk and meat are generally lower for large animals, such as cattle, than for small animals, such as sheep, goats and hens. However, this is a side effect of the defnition of the Fm and Ff because transfer coeffcients incorporate daily DMI which increases with animal size. A higher Fm or Ff value does not mean that animal products from small animals will be more highly contaminated than those from larger animals, as was mistakenly reported in the past.

An alternative, simpler, approach to quantify transfer is to remove the dietary intake used in the estimation of Fm and calculate the CR – the equilibrium ratio between the radionuclide activity concentration in the animal food product (Bq/kg fw) divided by the radionuclide activity concentration in the feedstuff ingested (Bq/kg dw) (Howard et al. 2009a, b, 2016b; Smith and Beresford 2005). For most radionuclides, the compiled CR data gives similar values between different livestock species; therefore those derived for one species could be applied to another, providing a more generic parameter than the transfer coeffcient. The advantage, especially for feld studies, is that daily DMI does not need to be calculated or a value assumed. To apply CR values when a number of different feed types are consumed suggests that the relative proportions of each dietary component need to be known. However, if the grassy component is the main source of radionuclide contamination (which is normally the case), then the intake from other components, especially if imported, can be discounted.

Tables of available CR and Tag values for various animal products are provided for radionuclides in TRS 472 (IAEA 2010) and are discussed in more detail in TECDOC 1616 (IAEA 2009). More recent analysis of transfer parameters for goat and cow milk is provided in Howard et al. (2016b, 2017). Using available CR geometric mean values given in these two papers, the predicted radionuclide activity concentrations at equilibrium have been calculated for feed that contains 1000 Bg/ kg dw. The fgures show the considerable difference in transfer to milk and meat for different radionuclides. For cow milk (Fig. 5.2), the relatively high transfer of I, Cs and Sr is evident, and U is also high although there are only seven reported values for this radionuclide and therefore less confdence in the value. For meat the transfer of Cs and I is also relatively high. There is no data for Sr probably because transfer to these products is low and not a cause for concern (Fig. 5.3). Furthermore, other radionuclides may be important for meat, notably S, U and Co. Notably, Po, which is an alpha emitter, has mid-range CR values for both milk and meat although based on relatively few data.

The aggregated transfer coeffcient is often used to quantify radionuclide transfer in non-intensive systems (termed a Tag, with units of m2 /kg) especially for animals and animal products. Tag is equal to the plant mass or animal tissue activity concentration (Bq/kg dw or fw) per unit area deposition density in the soil (Bq/m2 ). Tag values are easier to apply in the emergency response and the transition phases after a NRE as authorities will probably initially report contamination in deposition density units of Bq/m2 . Tag were frst proposed as more suitable for game animals after the Chernobyl NRE (Howard et al. 1991, 1996a, b). The determination of the

**Fig. 5.2** Predicted activity concentrations of some radionuclides in cow milk from dairy cows given feed that contains 1000 Bg/kg dw. Note the plot uses a logarithmic axis

**Fig. 5.3** Predicted activity concentrations of some radionuclides in meat for animals given feed that contains 1000 Bg/kg dw. Note the plot uses a logarithmic axis

underlying data for the deposition to soil needed to estimate aggregated transfer coeffcients (Tag) (Howard et al. 1991, 1996a, b) is a key component in the use of the Tag value. The spatial resolution of the data is limited, and the animals considered have different sizes of home range from which they derive their food, which introduces an averaging effect but unavoidably includes uncertainties.

The use of Tag amalgamates a large number of underlying processes and is inevitably less precise than other measures described above that can be used if dietary intake is known or can be reliably estimated. Tag values rather than CR values are commonly used for free-ranging animals and for game animals in forested areas. Tag values are provided for some radionuclides in TRS 472 (IAEA 2010) and are discussed in more detail in TECDOC 1616 (IAEA 2009).

## *5.2.9 Quantifcation of the Time Dependency of Radionuclide Activity Concentrations in Animal Products*

Assessments of the transfer of radionuclides via the human food chain are often based on equilibrium models using the parameter values given above. Such parameter values have limitations as they are not directly applicable to dynamic situations such as that which occurs after a NRE when radionuclide activity concentrations can change rapidly in the frst few days or weeks. Once the release of radionuclides ceases, radionuclide activity concentrations in animals and animal products decline with time. Models that simulate the dynamic accumulation and excretion of radionuclides in farm animals and animal products often use biological half-lives *T <sup>b</sup>* 1 2/ combined with Ff, Fm or CR values to estimate the change with time (IAEA 2009; Brown and Simmonds 1995).

#### *5.2.10 Biological Half-Life (T <sup>b</sup>* 1 2/ *) in Animal Tissues*

It is important to have some knowledge of the rate of loss from animals of ingested (or inhaled) radionuclides released after NREs. *T <sup>b</sup>* 1 2/ values are used to quantify how quickly agricultural or other animals will become decontaminated if they are fed uncontaminated feed or removed from the contaminated area. *T <sup>b</sup>* 1 2/ is defned as the time it takes for a given activity concentration in a tissue or an animal product, such as muscle, thyroid or milk, to reduce to half of its original activity concentration by processes excluding physical decay. *T <sup>b</sup>* 1 2/ values have been compiled in tables for different animal products by Fesenko et al. (2015).

*T b* 1 2/ for milk are normally described using a single exponential function. For cow milk, *T <sup>b</sup>* 1 2/ values for different radionuclides are similar at about 2 days after a single administration (Fesenko et al. 2015). For all radionuclides considered, the *T <sup>b</sup>* 1 2/ varied within a narrow range of 0.6–3.5 days with the shortest values for 131I and 132Te. The key message is that if grazing animals are removed from contaminated areas, or given uncontaminated (clean) feed, the radionuclide contamination of the milk will rapidly decline. If animals have been eating contaminated feed for a number of weeks, the rate of reduction in milk may be slower due to release and redistribution of radionuclides retained in different tissues.

There is variation in *T <sup>b</sup>* 1 2/ values due to age, species and tissues. Some differences occur because metabolic rate decreases with increasing body size. The *T <sup>b</sup>* 1 2/ tends to be longer for larger animals. For example, 137Cs loss from muscle is faster for small ruminants such as sheep and goats than for larger ruminants such as cattle. Compiled *T b* 1 2/ values for muscle of cattle reported by Fesenko et al. (2015) for isotopes of Sr, Cs and I are summarized in Table 5.4. The loss is best described by two exponential components. Data for other tissues and agricultural animals are summarized in this publication.


**Table 5.4** Range of values for biological half-lives of radionuclide activity concentrations and fraction of loss of radionuclide in the frst component in muscles of cattle

Summarized from Fesenko et al. (2015)

Losses of radionuclides from soft tissues tend to be shorter than those from bone (Fesenko et al. 2015). The *T <sup>b</sup>* 1 2/ values are relatively short for 132Te, 137Cs and 106Ru, whereas they are longer if the radionuclides associate with proteins or colloids (e.g. 144Ce). The longest *T <sup>b</sup>* 1 2/ values are for radionuclides which are deposited in bone, notably plutonium, americium and 90Sr with half-life of 600–3100 days in cattle. Animals and animal products often have fast and slow components of retention in tissues that are described by double exponential functions.

Some tissues which accumulate certain elements (and their radioisotopes) for metabolic requirements need to retain the elements and, consequently, have long *T <sup>b</sup>* 1 2/ values. Key examples are thyroid which accumulates iodine (and, therefore, radioisotopes of iodine such as 131I) and bone which accumulates Ca and its analogue 90Sr.

## *5.2.11 Ecological and Effective Half-Lives*

The long-term time-dependent behaviour of radionuclides in animal tissues can also be quantifed using ecological or effective half-lives which integrates all biological, environmental and ecological processes that cause a decrease of radionuclide activity concentrations in an animal product.

The ecological half-life, *T eco* 1 2/ , describes the reduction of amount of radionuclide (Bq) or activity concentration (Bq/kg) in a specifc environmental medium. The ecological half-life for animal products is equal to the time required for the radionuclide activity concentration in a target specifc animal tissue (or milk) to decrease by a factor of 2. It does not include the effects of physical radioactive decay of an isotope. Instead of estimating, *T eco* 1 2/ , from radionuclide activity concentrations, the analysis can also be applied to transfer parameters described above such as the CR or the Tag.

Effective half-lives are derived when the reduction in activity concentration, CR or Tag due to physical decay has been considered in the data. The effective half-life (*T eff* 1 2/ ) is defned as the time required to lose half of the radionuclide activity concentration (or the value of a transfer parameter) in the target (such as an animal tissue) and is a result of the interrelation between the physical (*T <sup>p</sup>* 1 2/ ) and biological (*T <sup>b</sup>* 1 2/ ) half-lives. The *T eff* 1 2/ can be calculated according to the following equation:

$$T\_{1/2}^{s\emptyset} = \left(T\_{1/2}^{\rho} \times T\_{1/2}^{\b}\right) / \left(T\_{1/2}^{\rho} + T\_{1/2}^{\b}\right)$$

For 131I which has a *T <sup>p</sup>* 1 2/ of 8 days and, for example, a *T <sup>b</sup>* 1 2/ of 138 days, the *T eff* 1 2/ can be calculated as:

$$T\_{1/2}^{\circ \circ} = \left(8 \times 1.38\right) / \left(8 + 1.38\right) = 1 \, 104 \, / 146 = 7.6 \, \text{days}.$$

Long-term time series data of radiocaesium and radiostrontium activity concentrations in animal products can be used to provide such values. The data for changes with time are ftted with either a single or double exponential giving either a single *T eff* 1 2/ or two *T eff* 1 2/ with an estimate of the proportion of loss that can be attributed to each component.

There are three prime sources of information on radionuclide half-lives in animal products: the Kyshtym and Chernobyl NREs and global fallout.

After the Chernobyl NPP NRE, there was a short-duration release with wellknown characteristics, high contamination levels and varying environmental characteristics (such as soil and climate). As a result, extensive data on the changes with time of 137Cs in animals have been obtained. Although the Fukushima NRE was also a relatively short-pulse release, there were few data for animals and animal products reported due to the disruption caused by the tsunami and earthquake and the relatively low importance of animal products because many agricultural animals were housed.

Global fallout represented a variable source term of radionuclides for the environment, as deposition of radionuclides occurred over a number of years, with maximum deposition observed in 1962–1964. A decade after the peak deposition period, when external contamination of plants was no longer occurring, long-term monitoring data provided an opportunity for deriving long-term effective half-lives for 90Sr and 137Cs.

## **5.3 Monitoring Animal Food Products**

Monitoring the presence of radioactivity entering the food chain is of prime importance to ensure the safety of animal products reaching the human consumer. Milk is a major constituent of the diet for children, and the presence of 90Sr, 131I and 137Cs needs to be carefully assessed. Regular examination of dairy and agricultural produce has been an important role of the veterinary and relevant authorities in many countries for many years. For example, milk in Europe is routinely analysed from the vicinity of nuclear sites to assess the exposure from ingested foodstuffs to the local population. The NREs at Chernobyl and Fukushima Daiichi intensifed surveillance globally.

After NREs, national monitoring programmes have been implemented and maps of the deposition of radioactive contamination prepared. The strategies for monitoring need to adapt to the changing characteristics of contamination that occur with time. Initially, 131I is potentially the major hazard in milk, after which monitoring for 137Cs in milk and meat is more likely to dominate. Therefore, sampling of milk from contaminated areas is given a high priority. Fortunately, collection and analysis of milk is much easier for 131I and radiocaesium than for other animal products. Analysis of milk from individual farms will give detailed information about the extent and character of the contamination. However, there is also some advantage in sampling milk from bulk sources such as tankers, which gives data representing several hundred cows sourced from a wide area.

If the radionuclide activity concentration in an animal product is above the intervention level, management options such as decontamination by clean feeding, or administration of Cs binders, which reduce its absorption in the gut, can be used to

lower the activity concentration before slaughter (see management options and datasheets). The time period needed to do this can be assessed based on measured radionuclide activity concentrations in muscle and the corresponding radiation safety standard (intervention level), utilizing knowledge of *T <sup>b</sup>* 1 2/ .

The use of live monitoring reduces the need to condemn meat and provides important information on the effectiveness of options which aim to reduce contamination of animals. Live monitoring has been used extensively after the Chernobyl NRE in both the USSR (subsequently termed the former Soviet Union (fSU) countries) and Western Europe to measure radiocaesium in a wide range of live ruminants and also for carcasses of wild animals to inform hunters of the contamination levels in the meat. The advantage of live monitoring is that estimates of radiocaesium activity concentrations can be made without the need to slaughter the animal. Live monitoring was less widely used after the Fukushima NRE due to the relatively low radiocaesium activity concentrations. Blood sampling and analysis was also used to assess animal product contamination.

## **5.4 Radionuclide Transfer to Intensively Farmed Agricultural Animals**

Although many different radionuclides may be released in a NRE, only a few present potentially serious health hazards to humans and animals. There are three key radionuclides: radioiodine, radiocaesium and radiostrontium, which are environmentally mobile in many production systems and which transfer readily to animal products. Because of their importance, specifc text on these three radionuclides is included for each subsection describing environmental transfer rates below.

This section describes various factors which infuence radionuclide transfer in intensively managed systems which are normally fertilized, and where the farm animals are in a good condition with high milk and meat production rates. Data for CR are provided in tables for different radionuclides and animal products based on compilations that were published by the IAEA (which used the term Transfer factor) in IAEA (2009, 2010).

## *5.4.1 Soil and Plant Aspects*

Soil is the main terrestrial sink of long-lived radionuclides deposited on the landscape, so the interaction between radionuclides and different soil characteristics is particularly important after the initial phase. In some cases, a substantial proportion of the radionuclide may become strongly associated with soil components and thereby becomes less mobile.

#### **5.4.1.1 Radioiodine**

The geochemistry of iodine is dominated by its volatility. The volatilization of organo-iodine compounds and elemental iodine from biological and non-biological sources in the oceans is a major component of its global cycle. Iodine is strongly enriched in soils 50–80 km inland from marine systems. Some wetland soils also form terrestrial sources of volatilized iodine. The dominant species of iodine in the aerobic soil environment are I−, IO3 <sup>−</sup> and I2.

Stable 127I is normally present in soils at an average concentration of 5 mg/kg dw. Typically, terrestrial plants and food crops contain from 0.07 to 10 mg/kg dw of stable I (127I). There is another natural isotope of iodine, 129I, that is much less abundant and which can be released during some nuclear activities, including NREs, but has a much lower radiological impact than 131I.

Radioiodine dissolves in water and moves easily from the atmosphere into different components of the environment. However, it readily absorbs to various soil components such as organic matter and soil minerals which limits the uptake of iodine through the plant root system. The two naturally occurring isotopes usually behave similarly although soil to plant uptake rates have been shown to differ in some soils (IAEA 2009).

The importance of soil to plant transfer for short-lived radioiodine isotopes, especially 131I, is generally thought to be negligible because of the short physical half-life of the iodine isotopes of relevance for internal dose to humans. After NRE, the interception by plants of the short-lived 131I in the emergency and transition phase is important, but in the longer term, accumulation of iodine in plants is only relevant for 129I.

The transfer of radioiodine from soil to plant in the emergency phase after NREs has received little attention from the research and radiation protection community. There are few compiled data for iodine transfer to plants (Table 5.5) with CR values varying from 0.1 to 5.0 for vegetative plant mass. No CR values for iodine are given for soil to grass species in TRS 472 (IAEA 2010). CR values for iodine are low for soils with a high cation exchange capacity and organic matter content. For grain (rye and wheat), which can be components of animals' diet, iodine CR values vary from 5 × 10−<sup>4</sup> to 8 × 10−<sup>3</sup> .


**Table 5.5** Soil to plant transfer factors for I (IAEA 2009, 2010) a


**Table 5.5** (continued)

a N - sample number, GM - goemetric mean - The mean is a geometric mean except where the number of data values (N) is less than 3, in which case it is an arithmetic mean. Further statistical information is given for a wider range of radionuclides in TECDOC 1616 and TRS 472 (IAEA 2009, 2010)

#### **5.4.1.2 Radiocaesium**

Radiocaesium has a high biological and ecological mobility as stable caesium is an alkali element, which is a chemical analogue of the biologically important element, potassium. Stable caesium exists in the environment in the 1+ oxidation state with concentrations ranging between 0.3 and 25 mg/kg dw. Radiocaesium is highly mobile in soils of both agricultural and free-ranging farming and harvesting systems in the emergency phase after NRE deposition.

In the transition phase and the subsequent existing exposure situation, after radiocaesium has been lost from the surfaces of plants, root uptake of radiocaesium from soil dominates. During the year following the Chernobyl NRE, the 137Cs activity concentration in plants declined by a factor of between 3 and 100 as root uptake from different soil types became the dominant contamination route. The most important process controlling plant root uptake of radiocaesium is the interaction between soil matrix and soil solution which depends primarily on the cation exchange capacity of the soil. For mineral soils, this is infuenced by the concentrations and types of clay minerals and the concentrations of competitive major cations, especially potassium and ammonium. The extent of selective, irreversible absorption differs for different clay minerals. Sorption of caesium to organic colloids and dissolved organic matter is not important in most (but not all) soils, so caesium is relatively more mobile in peaty and sandy soils. Organic soils often contain suffcient illitic clay minerals to immobilize radiocaesium present in organic soils, but the organic matter holds the clay in an expanded state, thereby maintaining availability of radiocaesium for plant uptake (Hird et al. 1995).

Accumulation of radiocaesium into crops and pasture is related to soil texture. On sandy soils, uptake of radiocaesium by plants is approximately twice as high as on loam soils mainly due to the lower concentrations of potassium in sand. Radiocaesium uptake from poor, often unfertilized, soils tends to exceed that of plants grown on fertile agricultural soils by several orders of magnitude. The highest 137Cs uptake by roots from soil to plants occurs in poor highly organic, boggy soils, which are one to two orders of magnitude higher than in sandy soils. Agricultural practices often reduce the transfer of radionuclides from soils to plant by physical dilution (e.g. ploughing) or by adding competitive elements during normal fertilization procedures. For radiocaesium, application of its analogue, potassium, is highly effective in reducing transfer to crops.

In TRS 472 (IAEA 2010), CR values for caesium have been given for a wide range of different plant groups (Table 5.6). Caesium uptake from soil by a single crop is less than 0.1% of the soil's content (Menzel 1963). CR values vary considerably from about 10−<sup>3</sup> up to about 1.0. Variations in the accumulation of 137Cs by plants due to differences in soil properties are up to a factor of 100, and the effect of biological features of plants causes up to a further tenfold variation (Alexakhin and Korneyev 1991). Mean caesium CR values are a factor of 2–10 lower than those of


**Table 5.6** Soil to plant for Cs (IAEA 2009, 2010) a


**Table 5.6** (continued)

a The mean is a geometric mean except where the number of data values (N) is less than 3, in which case it is an arithmetic mean. Further statistical information is given for a wider range of radionuclides in TECDOC 1616 and TRS 472 (IAEA 2009, 2010)


**Table 5.7** Radioecological sensitivity for soil-plant transfer of 137Cs/134Cs

strontium in most soils. The radioecological sensitivity of soils for radiocaesium can be broadly divided into the categories listed in Table 5.7.

A substantial proportion of the radiocaesium in soil gradually becomes less available for plant uptake as it becomes irreversibly bound by clay minerals. Differences in radioecological sensitivities of soils after the frst few years can have a signifcant impact on animal production contamination after an NRE. In some areas with low radiocaesium deposition densities and highly radioecologically sensitive soils after the Chernobyl accident, there were high radiocaesium activity concentrations in plants, and hence animals, which persisted for decades. Conversely, some areas of high deposition with soils of low radioecological sensitivity for radiocaesium had only low to moderate radiocaesium activity concentrations in plants and animals.

#### **5.4.1.3 Radiostrontium**

Natural strontium consists of 4 stable isotopes with mass numbers of 84, 86, 87 and 88. The content of stable Sr in the Earth's crust is about 3 × 10−<sup>2</sup> %. The chemical properties of strontium are determined by its position in group 2 of the periodic system and are typical for alkali-earth elements. Strontium is a close analogue of calcium and its behaviour in soils and transfer to plants are highly infuenced by the status of calcium in soils. Strontium is a highly mobile and bioavailable element that exists in the environment in the Sr(II) oxidation state at concentrations in soils that range between 50 and 1000 mg/kg dw. Strontium is usually present in the surface environment as a carbonate or a sulphate mineral. The dominant aqueous strontium species in natural waters over a broad pH range (2–9) is the free divalent Sr2+. Cation exchange is the key mechanism of absorption of Sr in soil.

Strontium is one of the most biologically mobile elements. Plant crops take up about 0.2% to 3% of the strontium in the soil (Menzel 1963). The Kyshtym NRE was the frst instance where large areas were contaminated by radionuclides, and 90Sr was one of the most important radionuclides released. Therefore, there is a large amount of available information on the behaviour of radiostrontium in soils. The uptake of 90Sr from soil to plants is affected by presence of both stable strontium and stable calcium (Gulyakin and Yudintseva 1962, Arkhipov et al. 1969). The interaction with these two stable elements is one of the main contributors to variability in Sr CR values. Strontium uptake by plants is generally highest from soils of low calcium content and, in many cases, of high organic matter content.

A large number of CR values are reported for Sr in TRS 472 (IAEA 2010) which are summarized in Table 5.8. Strontium CR values differ by more than a factor of 100, depending on soil properties and biological features of plants. Most of the variation in CR values of 90Sr can be attributed to the stable strontium concentrations in soil and its interaction with calcium. These two factors largely account for the low CR values, and also the large variability reported between individual plant


**Table 5.8** Soil to plant transfer factors for Sra


#### **Table 5.8** (continued)

a The mean is a geometric mean except where the number of data values (N) is less than 3, in which case it is an arithmetic mean. Further statistical information is given for a wider range of radionuclides in TECDOC 1616 and TRS 472 (IAEA 2009, 2010)

types, which are affected by the need and ability to accumulate calcium. The radioecological sensitivity of soils for radiostrontium can be broadly divided into two categories listed in Table 5.9.

Decrease in exchangeable strontium in soil occurs very slowly, so the availability of soil 90Sr to plants decreases only slightly with time. Relatively higher rates of 90Sr vertical migration occur in sandy soils and lower rates in peat soils.


**Table 5.9** Radioecological sensitivity for soil-plant transfer of 90Sr

#### **5.4.1.4 Other Radionuclides**

Brief information is provided here on the other radionuclides of potential concern after an NRE based on text from IAEA TRS 472 (IAEA 2010) and TECDOC 1616 (IAEA 2009). Further, more detailed information, including CR values, can be accessed in these publications.

Transuranic elements (Am, Cm, Pu, Np) exhibit a complex soil chemistry, because of various degrees of oxidation, absence of stable carriers and high tendencies to complexation and hydrolysis. CR values for transuranic elements vary from about 100 to about 10−<sup>6</sup> . Due to these relatively low CR values, the activity concentrations of these radionuclides in fruits and grains are 10–1000 times lower than in the vegetative parts of plants. Accumulation of these elements decreases in the order Np > Am > Cm > Pu. Hydrolysis is a major factor infuencing the behaviour of Am and Cm in soils. The mobility of Pu depends on its valency form and decreases in the order Pu (V) > Pu (VI) > Pu (III) > Pu (IV).

The fssion products (89Sr, 90Sr, 134Cs, 137Cs, 129I, 131I, 95Zr, 95Nb, 103Ru, 106Ru, 141Ce, 144Ce) include a diverse class of elements. Of these radionuclides, 95Zr, 95Nb, 103Ru, 106Ru and 141Ce, 144Ce are poorly accumulated by agricultural plants because of their strong sorption in soil, leading to low CR values. Soil pH and organic matter content are the most signifcant soil characteristics that infuence the behaviour of these radionuclides. Up to 99% of the plant uptake of these radionuclides is retained in the roots, so there is little transfer to above-ground plant parts that may be consumed by animals. CR values vary by factors of 10–30 for different soils, with the lowest plant uptake for 95Zr and 141Ce, 144Ce.

The activation products (60Co, 65Zn) are radioisotopes of biologically important microelements. They have high mobility in soil-plant systems and, therefore, relatively high CR values. In particular, 65Zn has CR values from 1.0 to 15.0, but it is not likely to be released in large quantities after a NRE.

The behaviour of other radionuclides not mentioned above depends on the oxidation-reduction potential of the soil, the acidity of soil solution and the organic matter content.

## *5.4.2 Dairy Production*

The consumption of milk contaminated by 131I, 90Sr and 137Cs is potentially one of the main contributors to the internal dose to humans after a NRE.

The highest contamination levels in plants are normally reached during the urgent response phase when radionuclides are intercepted by plants and before they are lost from the plant surfaces. At the time of the Chernobyl NPP NRE, vegetation was at different growth stages in different countries that were affected depending on latitude and elevation. In the frst few weeks, interception on plant leaves of dry deposition and atmospheric washout with precipitation were the main pathways of contamination. Because radionuclides were released over a period of 10 days, and plant growth had commenced in the adjacent areas (as it was late April and early May), radionuclides were intercepted by plant surfaces including pasture grass. In contrast, because the Fukushima Daiichi NRE occurred in mid-March, there was much less plant biomass present that could intercept the radionuclides in the atmosphere. Therefore, in the prevailing intensive farming systems, the initial extent of contamination of most plants was much lower than that after the Chernobyl NRE.

In the USSR, the food-production systems at the time of the Chernobyl NRE were largely collective farms and small private subsistence farms. The collective farms had an intensive farming approach using land rotation combined with ploughing and fertilization to improve productivity. In contrast, the traditional small subsistence or "private" farms usually had privately owned livestock which often grazed in forest clearings to which they applied manure to improve yield instead of artifcial fertilizers. Root uptake of radiocaesium becomes the key transfer route to milk after the emergency response phase and the early part of the transition phase. The highest activity concentrations of radionuclides in most agricultural animal product foodstuffs occurred in the growing season of 1986. In many regions of the USSR, as well as in Germany, France and Southern Europe, dairy animals were already grazing outdoors, so some contamination of cow, goat and sheep milk occurred. In contrast, in Northern Europe, in the early spring, most dairy cows, sheep and goats were not yet on pasture; therefore, there was little milk contamination.

The extent of transfer of radionuclides into cow, sheep and goat milk has been reported as both Fm and CR values in the IAEA publications TECDOC 1616 and TRS 472 (IAEA 2009, 2010). The data for cow and goat milk has recently been updated during the IAEA MODARIA programme (Howard et al. 2016a, b, 2017). Fm and CR values for selected radionuclide elements that are most relevant for NRE in the MODARIA tables are shown in Tables 5.10 and 5.11 for cow milk and Tables 5.12 and 5.13 for goat milk, respectively. Available parameter values for other radionuclides/elements can be found in Howard et al. (Howard et al. 2016a, b, 2017).

For some radionuclides released from previous NREs, there are few data, notably for 210Po and 95Zr. Also, data for transuranic elements such as plutonium, americium


**Table 5.10** Transfer coeffcients (Fm, d/kg) for radionuclides relevant for NREs for cow milk

Howard et al. (2017)

**Table 5.11** Concentration ratios (CR, kg/L) for radionuclides relevant for NREs for cow milk


Howard et al. (2017)

and uranium are sparse. However, there are a large number of data for the most important radionuclides, 134Cs, 137Cs, 90Sr and 131I, and, therefore, there is more confdence in these transfer parameter values. Various factors that lead to the variability in the transfer values, such as the effect of the intake of a close stable element analogue to a radionuclide, is discussed for the three most important radionuclide elements below.


**Table 5.12** Transfer coeffcients (Fm, d/kg) for radionuclides relevant for NREs for goat milk\*

*N* Sample size, *AM* arithmetic mean, *ASD* arithmetic standard deviation, *GM* geometric mean, *GSD* geometric standard deviation,

Howard et al. (2016a, b)

\*The mean is a geometric mean except where the number of data values (N) is less than 3, in which case it is a n arithmetic mean. Further statistical information is given for a wider range of radionuclides in TECDOC 1616 and TRS 472 (IAEA 2009, 2010)


**Table 5.13** Concentration ratios (CR, kg/L) for radionuclides relevant for NREs for goat milk\*

*N* Sample size, *AM* arithmetic mean, *ASD* arithmetic standard deviation, *GM* geometric mean, *GSD* geometric standard deviation,

Howard et al. (2016a, b)

\*The mean is a geometric mean except where the number of data values (N) is less than 3, in which case it is a n arithmetic mean. Further statistical information is given for a wider range of radionuclides in TECDOC 1616 and TRS 472 (IAEA 2009, 2010)

#### **5.4.2.1 Radioiodine**

The deposition of atmospheric iodine (mainly from marine sources) onto the aerial parts of plants is an important contributor to stable iodine (127I) in plants and is a major source for grazing animals. Iodine intake by agricultural animals is also enhanced by consumption of cattle feed fortifed with iodine and the use of iodinecontaining sterilants in the dairy industry.

Unlike many of the other radionuclides that affect the food chain, stable iodine is essential for normal growth and development in animals (including humans). It accumulates in various organs and tissues of the body, notably the thyroid. The major function of the thyroid gland is to produce the thyroid hormones, T4 (thyroxine) and the more active T3 (triiodothyronine), so it accumulates iodine from the plasma to produce these compounds.

Raw milk is one of the foods that are most likely rapidly to become contaminated by radioiodine as livestock feeds on grass which has been contaminated by deposited radioiodine. Radioiodine isotopes intercepted by pasture vegetation ingested by grazing animals such as dairy cows, goats and sheep are quickly and completely absorbed through the gut (Howard et al. 1996a, b; Vandecasteele et al. 2000). The consumption of different physico-chemical forms of iodine does not change the extent of true absorption which is consistently complete (i.e. Fa is 1) (Howard et al. 1996a, b; Vandecasteele et al. 2000). Furthermore, there is no reduction in gut absorption of radioiodine isotopes due to enhanced stable iodine intake. Iodine is rapidly absorbed into the blood plasma where it circulates as an iodide and from which it is subsequently accumulated in the thyroid. Radioiodine is also transferred into the mammary gland and excreted via milk. It is also excreted via urine.

The capacity of the thyroid to concentrate iodine magnifes the hazard imposed by 131I as it is accumulated in a similar manner to stable iodine. Therefore, it accumulates in the thyroid and also rapidly transfers into the milk within 30 min of introduction into the body (Thorell 1964). Peak radioiodine activity concentrations will be reached in 6–12 h. Radioactive iodine can also be absorbed via the lung into the plasma.

Goat's milk and sheep's milk contain approximately tenfold higher radioiodine activity concentration than cow's milk. For cows the milk/plasma ratio has been reported as 0.6–5.5, whereas for sheep and goats, it was 2–24 (Lengemann 1970).

In a controlled feeding experiment, using herbage recently contaminated by fallout from the Chernobyl NRE, the transfer coeffcient of 131I to sheep milk was 0.3 ± 0.017 d/L (Howard et al. 1993). These data are similar to Fm values reported for iodine for sheep milk in TRS 472 (IAEA 2010) of 0.23 d/L (geometric mean) and varied from 0.03 to 0.9 d/L. Similar values of Fm (range 0.015–0.020 d/L) after the Chernobyl NRE were reported for stable iodine in dairy cows by Vandecasteele et al. (2000). The daily proportion of 131I intake which was secreted in sheep milk was 5.6 ± 0.035% which is an order of magnitude higher than for cattle and agrees with the higher transfer of stable iodine from plasma to milk which occurs in sheep and goats. The lactation phase does not seem to have a signifcant effect on iodine transfer to milk (Vandecasteele et al. 2000).

As for humans, it is important to establish the effect of stable iodine intake for dairy animals. In controlled experiments, Vandecasteele et al. (2000) reported that the mean Fm values for oral radioiodine to milk increased from 0.020 d/L for a low stable iodine intake to 0.024 d/L for a moderate stable iodine rate. There was a signifcant decrease in the transfer to milk for the high stable dietary iodine intake rate (mean Fm of 0.018 d/L) compared with the moderate treatment. The differences for the three stable iodine treatments were due to differential affnities and saturation levels of the thyroid and milk pathways competing for the available iodine.

Associated modelling studies confrmed that the stable iodine intake may affect the partitioning of iodine between thyroid, milk and excreta (Crout et al. 2000). The

model was used to predict the effects of variation in stable iodine intake and the extent of consequent chemical contamination of milk by stable iodine. The predicted time taken for radioiodine to reach peak concentrations in milk following a deposition event varied signifcantly (ca. 2 days) over a range of stable iodine intakes. Administration of low amounts of stable iodine of <100 mg/d to dairy animals could increase Fm, whereas >150 mg/d stable iodine would reduce radioiodine transfer to milk. However, administration of suffcient stable iodine to reduce the radioiodine transfer to milk would result in stable iodine concentrations in milk that were greatly in excess of internationally advised limits. Therefore, increased stable iodine supplementation should not be used as a countermeasure to reduce radioiodine transfer to milk due to the elevated stable iodine in milk (Howard et al. 1996a, b).

The *T <sup>b</sup>* 1 2/ of 131I measured in ewes that were moved from contaminated pasture to housing and then fed an 131I-free diet was 1 day, accounting for 97.4% of the reduction in the 131I activity concentration in milk. Data on *T <sup>b</sup>* 1 2/ in cow, goat and sheep milk show consistently fast reduction at 1–2 days (Howard et al. 1993; Fesenko et al. 2015), and it is longer in various organs, e.g. thyroid, 100 days; bone, 14 days; and kidney, spleen and reproductive organs, 7 days.

Radioiodine in milk was an important contributor to internal dose in the emergency response phase and the initial part of the transition phase after the Chernobyl NRE. The ingested radioiodine was completely absorbed in the gut and rapidly transferred to the animals' thyroid and milk (within about 1 day). Throughout the contaminated areas of the USSR and parts of Eastern and Western Europe, peak 131I activity concentrations in milk occurred rapidly after deposition in late April or early May 1986 depending on when the radioactive contamination reached each county. Therefore, transfer of 131I to milk was the initial priority.

The 131I activity concentration in milk after the Chernobyl NRE decreased with an *T eff* 1 2/ of 4–5 days due to its short physical half-life and the reduction in iodine activity concentrations on plants due to various removal processes from leaf surfaces. The removal rate, measured as a mean weathering half-life on grass, was about 9 days for radioiodine and 11 days for radiocaesium (Kirchner 1994).

#### **5.4.2.2 Radiocaesium**

Radiocaesium can be ingested or inhaled. The most important isotope with a physical half-life of 30 years is 137Cs. Cs-134 has a shorter physical half-life of ~2 years, so its relative importance declines much faster than that of 137Cs.

After the Chernobyl NRE, from June 1986, radiocaesium was the dominant radionuclide in most environmental samples and in food products contributing to the human food chain. The contamination of milk with radiocaesium decreased during spring 1986 with an *T eff* 1 2/ of about 2 weeks due to weathering, biomass growth and other natural processes. The amount and type of feed ingested by dairy cattle changes considerably during the course of lactation and with season leading to temporal variations in radiocaesium transfer to milk. Radiocaesium activity concentrations increased in many countries during winter 1986/1987 due to cows being fed with contaminated hay harvested in spring/summer 1986.

The physical and chemical form in which radiocaesium is ingested substantially affects the extent of absorption across the gut and the subsequent radiocaesium activity concentrations in animals and animal products. Radiocaesium absorption varies over a 50-fold range, depending upon dietary source (Beresford et al. 2000). Radiocaesium recently deposited after the Chernobyl NRE onto leaf surfaces was initially less available for gut absorption (Fa of 0.24) than that when it was plantincorporated (Howard et al. 1989; Beresford et al. 2000). Once radiocaesium is incorporated into the internal plant structure through leaf absorption or root uptake, it is more highly absorbed in the GI tract (Fa of 0.8–1.0). The absorption of sediment- or soil-associated radiocaesium may be lower than that in plant-incorporated form and will vary for different types of soil (as does plant uptake) (Beresford et al. 2000). The availability for biological uptake of radionuclides associated with fuel particles that were deposited mostly within a 50 km radius of the Chernobyl NPP was lower than for plant-incorporated sources.

There were differing rates of 137Cs transfer to milk in areas with different soil types. The transfer to milk declines in the order as follows: peat bog > sandy and sandy loam > chernozem and grey forest soils.

The *T <sup>b</sup>* 1 2/ of radiocaesium in milk is fast at 1–2 days (Fesenko et al. 2015) so the 137Cs or 134Cs activity concentrations in milk from dairy cows removed from contaminated areas declined rapidly. The long-term time trend of radiocaesium activity concentrations in milk (and meat) roughly follows that for vegetation (with a time lag) and can be divided into two time periods (Fesenko et al. 1997). For the frst 4–6 years after deposition of Chernobyl NRE radiocaesium, there was an initial fast decrease with an ecological half-life between 0.8 and 1.2 years. Later, the rate of decline was slower and varied with soil type (Fesenko et al. 1997).

#### **5.4.2.3 Radiostrontium**

The behaviour of strontium in all organisms is strongly infuenced by the presence of its analogue, calcium. The calcium requirement of an animal varies due to factors such as milk yield and stage of pregnancy (Howard et al. 1997). In response to these requirements, the calcium intake of dairy animals changes throughout the year. Typically, the calcium intake by dairy goats will range from 15 to 30 g/d, whilst that of cows will be 70–150 g/d (Beresford et al. 1998).

The gastrointestinal absorption of radiostrontium is less dependent upon dietary source than that of radiocaesium. Calcium status is generally the controlling infuence on strontium absorption. The absorption of calcium is homeostatically controlled, and the extent of absorption is determined by animals' requirement for growth, milk production, etc. When calcium intake is in excess of requirement than for all sources, the Fa for Sr is 0.1–0.3. For a given calcium requirement, Ca absorption is inversely proportional to dietary Ca intake. Hence, Sr absorption should also be inversely proportional (Comar 1966). Collated data from experiments after the Kyshtym NRE, which included a number of data with relatively low ratios of calcium intake to requirement, and other data reported during the period of global weapons fallout, showed a clear reduction in the Fm of 90Sr with an increasing ratio of intake/requirement for calcium (Beresford et al. 1998).

The use of the reported mean Fm for radiostrontium in Howard et al. (2016b, 2017) is only appropriate for productive agricultural systems where calcium is readily available (Comar 1966; Howard et al. 1997). Fm may be higher in low-productivity regions with low calcium intakes.

The *T <sup>b</sup>* 1 2/ of 90Sr in milk is fast at 1–2 days (Fesenko et al. 2015), so the 90Sr activity concentrations in milk from dairy cows that are removed from contaminated areas will decline rapidly.

## *5.4.3 Meat and Offal Production*

Different radionuclides are accumulated in different tissues. The most important tissue for the food chain of many countries is muscle for which the data is much more extensive than that for other accumulating tissues.

#### **5.4.3.1 Transfer of Radionuclides to Meat**

Within a few weeks of the Chernobyl NRE, there were high reported 137Cs and 134Cs activity concentrations in the muscle of ruminants, resulting in intensive monitoring of meat from cattle, goats, sheep, reindeer, game and fsh. Data on the transfer of radiocaesium to different animals has been reported from many countries after the Chernobyl NRE; there are much more data available for cow meat than for any other agricultural animal. The transfer of radiocaesium to meat is higher than that to milk. The extent of transfer of radionuclides into the meat of different types of animals is given as both Ff and CR values in TRS 472; selected relevant values for Ff are shown in Tables 5.14, 5.15, 5.16, 5.17 and 5.18 and for CR in Table 5.19.


**Table 5.14** Transfer coeffcients for radionuclides relevant for NREs to cow meat d/kg

IAEA (2010)


**Table 5.15** Transfer coeffcients for radionuclides relevant for NREs to sheep meat d/kg

IAEA (2010)

**Table 5.16** Transfer coeffcients for radionuclides relevant for NREs to goat meat d/kg


IAEA (2010)

**Table 5.17** Transfer coeffcients for radionuclides relevant for NREs to pig meat d/kg


IAEA (2010)

**Table 5.18** Transfer coeffcients for radionuclides relevant for NREs to poultry meat d/kg


IAEA (2010)


**Table 5.19**Concentration ratios for radionuclides relevant for NREs to the meat of different animals B. Howard

IAEA (2010)

#### **5.4.3.2 Other Accumulating Tissues**

The transfer of radionuclides to eggs is high compared with meat. Transfer parameter values for eggs are listed in Table 5.20 and are largely based on data from chickens. There are Ff values reported by a number of sources for the three key elements, I, Cs and Sr, but few values for most other elements.

#### **5.4.3.3 Target Tissues for Different Radionuclides**

Some radionuclides accumulate in specifc organs. The key accumulating organs in animals for radionuclides released during NREs is shown in Table 5.21. The table is largely based on a review of Russian language literature which reported Ff values


**Table 5.20** Transfer coeffcients for radionuclides relevant for NREs to egg contents d/kg

IAEA (2010)

**Table 5.21** Accumulating organs for different radionuclides


Fesenko et al. (2018)

for various organs consumed by humans (Fesenko et al. 2018). Radiocaesium is present at similar activity concentration in most soft tissue (and tends to be higher in the kidney, but not consistently) with lower accumulation in bone and adipose tissue. Many heavy metal radionuclides accumulate in the liver. No relevant transfer parameter data for 210Po or 95Zr have been identifed.

## **5.5 Radionuclide Transfer in Non-intensive Animal Production**

The Chernobyl fallout contaminated large areas of the terrestrial environment with a major impact on animal production on unimproved land. Depending on the weather patterns for the frst 2 weeks after the NRE, parts of Eastern and Western Europe were contaminated, especially where the passage of the contaminated fallout in the atmosphere coincided with heavy rainfall. These areas included upland areas and clearings within, or bordering woodland. They are collectively termed here as non-intensive systems (but also called seminatural, extensive systems or free-ranging systems). In these areas, unfertilized, highly organic soils are often used for extensive agricultural production of animal products, mainly for grazing by ruminants, such as sheep, goats, reindeer and cattle, on alpine meadows and upland regions. Therefore, problems with animal products were widely experienced not only within the USSR but also in many other countries in Europe.

The initial impact of radionuclide deposition on these systems, as for intensive systems, depended on the extent of interception by plants consumed by the animals. Thereafter, soil to plant to animal transfer dominated. These systems are potentially important after NREs due to the prevailing soil types and vegetation species which can allow relatively higher, and more prolonged, radiocaesium transfer to animals compared with intensively managed agricultural production (Howard et al. 1991, 1996a, b).

Normal agricultural practices which often reduced the transfer of radionuclides from soils to plant by physical dilution (e.g. ploughing) or by adding competitive elements (e.g. fertilizing) are generally not applied in these systems due to the low depth of soil and presence of stones and rocks. The low potassium status and high organic matter content of the soil in these often-unfertilized areas enhance the movement of radiocaesium from soil constituents into the soil solution from which it can be taken up by plants.

After the Chernobyl NRE, the high radiocaesium uptake from peaty soil in unmanaged (termed extensive) grassland was particularly important for a number of European countries where such land was used for the grazing of ruminants and the production of hay. Contamination with radiocaesium in animal food products from these radioecologically sensitive, non-intensive ecosystems often persisted for decades, even though the original deposition may not have been high (Howard et al. 2002). This is largely because there was prolonged and signifcant plant uptake of

radiocaesium from soil and some plant and other species consumed by animals accumulated high levels of radiocaesium, such as ericaceous species (e.g. heather) and mushrooms.

Animals kept on unimproved land had higher radiocaesium activity concentrations than those from agricultural systems after both the Chernobyl and Fukushima Daiichi NREs. Little information is available for other radionuclides and there is no current evidence of signifcant long-term problems with other radionuclides in these production systems.

## *5.5.1 Dairy Production in Low-Productivity Areas*

In some countries, such as Austria and Norway, non-intensive systems are used during the growing season for dairy animals where suitable upland pastures exist and there are adequate facilities to carry out milking within a suitable distance. Some of these mountainous regions of Western European countries were amongst the most contaminated territories outside of the former USSR after the Chernobyl NRE. In these non-intensive systems, vertical migration rate of 137Cs is slow, so it remains in the upper soil layer where root uptake of nutrients often occurs. A relatively high radiocaesium soil-to-vegetation transfer was reported in some of these pastures (e.g. Norway). Activity concentration of 137Cs in milk in such areas rose quickly in the frst 2 weeks after the dairy animals began to graze these regions (around mid-June) and remained elevated until the animals were removed in the autumn. Activity concentrations of 137Cs in milk on such meadows during summertime were several orders of magnitude higher than in milk from lowland areas and valleys, where intensive agriculture occurs (IAEA 1994; Lettner et al. 2007). The 137Cs activity concentration of milk would have remained above the intervention levels for many years if remediation options had not been applied. For example, 137Cs activity concentrations in milk from Austrian sites remained high even 17 years after the Chernobyl NRE refecting the persistent elevated transfer of radiocaesium from poorer soils in alpine pastures and regions with silicate bedrock.

Considerably longer ecological half-lives have been observed in cow's milk from alpine pastures than in cow's milk from lowland production sites. For the period 1988–2006, Lettner et al. (2007)) derived ecological half-lives of 0.7–1.4 years for the fast loss component and of 9.3–12.7 years for the slow loss component of 137Cs activity concentrations in cow's milk. Later studies showed that the *T eff* 1 2/ and mean altitude of the alpine meadows sites were positively correlated, with higher altitude sites having signifcantly longer half-lives than those at lower altitudes. Depending on the site, half-lives varied from about 4 and 15 years (Lettner et al. 2009).

## *5.5.2 Meat Production in Low-Productivity Areas*

After the Chernobyl NPP, the transfer of radiocaesium to meat of grazing stock in non-intensive areas was also higher than that in lowland regions in several countries, including Norway and the United Kingdom due to the same factors discussed for dairy animals. Free-ranging stock that graze these areas include sheep, cattle and goats; such land is also used for rearing game animals such as grouse, pheasant and partridge.

There was considerable variation in radiocaesium activity concentrations between individual animals within the same grazing areas. Reasons for the variation included individual preferences in the areas being grazed as there was considerable spatial variation on the deposition density of radiocaesium, even within a few metres, and the range of different vegetation species present.

Metabolic variation was also important. For example, there was considerable variability in the radiocaesium activity concentration of muscle between individual sheep in the same free ranging fock in contaminated upland areas of the United Kingdom (Beresford et al. 1996). Certain sheep within a fock were consistently amongst the most contaminated, whereas others were consistently the least contaminated (Beresford et al. 1995; Walters 1988). When ionic radiocaesium was orally administered to 22 sheep under controlled conditions, the Ff varied by threefold. The *T <sup>b</sup>* 1 2/ in muscle varied from 5 to 19 days with a mean of 9.8 days. Changes in live weight and feed intake during the study together accounted for 72% of the variation in the Ff values, and live weight change accounted for 56% of the observed variation in biological half-life. The data suggested that variation in metabolism of radiocaesium contributes to the variability in radiocaesium activity concentrations within sheep focks in areas contaminated by Chernobyl fallout.

Contaminated animals raised for meat production cannot be sampled as easily as the milk from dairy animals. The development of equipment that was suitable for live monitoring of animals *in situ* in these areas was important in managing the situation and developing suitable remediation strategies.

## **5.6 Radionuclide Transfer to Game Animals**

## *5.6.1 Forest Environments*

The primary concern regarding forests from a radiological perspective is the longterm contamination of the forest environment and its products with 137Cs due to its 30-year half-life. However, 134Cs should not be forgotten as it may be present in large quantities and can signifcantly contribute to the contamination of animal products for more than a decade. The meat of game animals grazing in contaminated forests often has high radiocaesium activity concentrations.

Other radionuclides in forests such as the plutonium isotopes are of limited signifcance for animal products due to their low environmental mobility.

Substantial radioactive contamination of forests occurred following the Chernobyl and Fukushima Daiichi NREs. The deposition density of 137Cs in Ukraine, Belarus and Russia exceeded >10 MBq/m2 in some forested areas. In several Western European countries, such as Finland, Sweden, Norway, Germany and Austria, the deposition density of 137Cs was also relatively high compared to other sources such as global fallout. After the Fukushima NRE, the extensive forest catchments in Fukushima prefecture covered about 70% of the most contaminated areas.

In many of the affected countries, the extent of game meat consumption from seminatural areas and forests by the general population was low compared with agricultural animal products. However, there were specifc groups such as hunters who may consume relatively large quantities of game meat. Tree canopies, particularly at forest edges, are effcient flters of atmospheric pollutants of all kinds. The primary mechanism of tree contamination after the NREs was direct interception of radiocaesium of between 60 and 90% of the initial deposition by the tree canopy (Tikhomirov et al. 1994; Kato et al. 2012). Radionuclides on tree surfaces were gradually transferred to the upper layers of soil through natural weathering and wash-off by rainwater. Within a few years after deposition, most of the radiocaesium was transferred from the tree canopy to the underlying soil which became the major repository of radiocaesium contamination within the forest. The upper soil layers acted as a long-term sink and source of radiocaesium contamination of forest vegetation and animals.

A wide range of plants and fungi are consumed by wild animals in forests. Higher transfer of radiocaesium occurred from soil to some plants including grasses, lichens and berries, and also to mushrooms and truffes. Individual plant and fungal species differed greatly in their ability to accumulate radiocaesium, with particularly high radiocaesium activity concentrations in some mushroom species (IAEA 2010). The high levels of contamination in various mushroom species are refected in generally high soil-mushroom Tag values which can vary by a factor of about 2000 (IAEA 2009, 2010).

Contamination of mushrooms in forests is often much higher than that of forest fruits such as bilberries. The Tag values for forest berries range from 0.02 to 0.2 m2 / kg (IAEA 2009, 2010).

The shooting of game animals or snaring of other species is often, but not always, confned to certain seasons, so the short-term impact of radionuclide deposition can initially be highly dependent on when the NRE occurs relative to the shooting season. After the transition phase, the spatial and temporal variability in contamination of game animals is affected by many different factors including:


Signifcant variations occur in the body burden of radiocaesium in game animals due to the seasonal availability of the various components of their diet (IAEA 2009). Species-specifc information on how the above factors affect some of the main species affected by radiocaesium deposition is provided in Table 5.22.


**Table 5.22** General trends for radiocaesium in forest animals

Based on Skuterud et al. (2004), Strebl and Tataruch (2007), IAEA (2009, 2010)


**Table 5.23** Comparison of Tag values for game animals obtained within 5 years after the Fukushima Daiichi and Chernobyl NREs

Tagami et al. (2016), IAEA (2009)

Tag values have been reported in numerous publications, but it is diffcult to identify generally applicable trends due to the wide variation in spatial and temporal trends. Tag values are often higher for wild boar than other species and the difference seems to increase with time. Also Tag values for the larger ruminants such as red deer and moose are often lower than for small deer and wild boar. Tag values compiled for the frst 5 years after the Fukushima Daiichi accident, for three species, are compared with the equivalent period for Chernobyl NRE in Table 5.23.

Since the NREs, the natural decontamination of forest plants and, therefore, animals has been much slower than that in agricultural areas. Wild ruminants with access to agricultural land often have lower radiocaesium concentrations than those grazing inside forests (Kiefer et al. 1996).

The prevailing conditions in many forests, with often low potassium contents and high organic matter contents in the upper soil layers, and consequently high uptake of radiocaesium by some plants and mushrooms, lead to long *T eff* 1 2/ of radiocaesium in game animals. After the Chernobyl NRE, the *T eff* 1 2/ of 137Cs in game meat varied from about 3 to 10 years. Over several decades, the physical decay rate of 137Cs has been the key factor determining the rate of reduction in 137Cs activity concentrations in some forest game animals.

## **5.7 Impacts on the Health of Livestock Exposed to Nuclear Contamination**

A key feature of both the Kyshtym and Chernobyl NREs was the difference in the impact on the health of livestock between the emergency response phase, when there was an initial, intensive short-term radiation impact, and the subsequent transition phase, with a slow decline in the dose rate. Doses from radioactivity that may endanger the health and well-being of livestock are only likely to occur in the immediate vicinity of a major NRE involving a nuclear reactor.

To reliably estimate the impact of post-NRE doses to farm animals, information needs to be collected soon after the NRE for animals remaining in these areas. The limited data available for the period after NRE have been reviewed by Fesenko (2019) for the Kyshtym NRE and Geras'kin et al. (2008) and other sources given below who focused on the Chernobyl NRE.

The exposure routes for animals remaining in areas that have been highly contaminated include:


There are considerable challenges associated with collecting relevant data for agricultural animals after a NRE. It is diffcult to accurately estimate the doses received which vary greatly with location and with time. Some problems experienced after the Chernobyl NRE given by Geras'kin et al. (2008) include:


*Dose Estimation After the Kyshtym NRE* Information from the Kyshtym NRE is summarized here based on a recent review by Fesenko (2019). In contrast to the Chernobyl NRE, the Kyshtym NRE did not release short-lived radioiodine isotopes. Domesticated cattle and sheep were the most exposed agricultural animals after the Kyshtym NRE with initial radiation effects for domesticated animals being observed shortly after the NRE. The decision to evacuate both the public and animals living in the most affected areas was taken 12 days after the NRE. During that time the animals were grazing pasture with a total contamination density (combining all radionuclides released) of around 900-1000 MBq m−<sup>2</sup> and received estimated external doses of 1.4–3.0 Gy. The corresponding doses to the GI tract were higher and reached 4–24 Gy. The radiation doses resulted in a high mortality rate of exposed cattle with symptoms that could be attributed to acute radiation sickness, including bleeding of mucous membranes and leucopoenia.

The cattle grazing slightly further away from the most contaminated area received lower external doses of about 0.1 Gy and doses to the GI tract of 1.0–2.0 Gy. These animals survived although some detrimental changes occurred in the bloodproducing metabolic systems that produce blood components over the frst 6 months.

Similar effects were observed for highly contaminated sheep. Sheep grazing on sites close to the source of the release received external doses of 1.4–3 Gy and absorbed doses to the GI tract of 8–54 Gy during the frst 12 days after the NRE and before evacuation. As for the cattle, the doses caused symptoms of acute radiation sickness and death in most of the animals.

No substantial radiation effects were observed in sheep at less contaminated sites (100–200 MBq m−<sup>2</sup> of total radioactivity). For these sheep, the calculated doses during the frst 12 days after the NRE were 0.1–0.2 Gy, and the GI tract doses were 2–4 Gy. Over the next few months, temporary changes in the blood-producing system of these animals occurred after evacuation.

An absorbed dose of around 1 Gy to the GI tract of large herbivores led to a reduction in wild game populations. Some reduction in the number of moose and roe deer occurred in 1957–1958 in areas where the GI tract doses would have been 10–30 Gy. However, increased mortality of large animals was not documented due to the diffculty in locating animals. At sites with a lower 90Sr deposition density of 37 MBq m−<sup>2</sup> , animals could have received an additional external dose of 2–3 Gy. At such doses, early radiation effects and even death of some animals may have occurred.

*Dose Estimation After the Chernobyl NRE* Appraisals of the effects of radiation on livestock inhabiting the area immediately surrounding the nuclear power plant at Chernobyl have been reported in the last decade (Fesenko et al. 2005; Geras'kin et al. 2008). Initially, there was an acute phase of radiation exposure of approximately 3–4 weeks that was due to the short-lived radionuclides, including 131I deposited on vegetation and the ground surface. High exposure of the thyroids of vertebrates occurred due to inhalation and ingestion of radioiodine isotopes. Approximately 80% of the total radiation dose accumulated by animals were received within the frst three months after the NRE, mostly due to ß-radiation. A second phase of exposure followed in the autumn of 1986 when the short-lived radionuclides had decayed, due to environmental pathways that transported various longer-lived radionuclides. The third stage of radiation exposure, continuing to the present day, is chronic exposure due mainly to 137Cs.

A review of radiation doses and effects by Geras'kin et al. (2008) for the Chernobyl NRE has been used as the source of much of the information summarized here. The large-scale and heterogeneous radioactive contamination of the affected areas led to a variety of responses at different levels of molecular and cellular biological organization. The most affected livestock were within the 30 km Chernobyl NPP zone when the highest exposures occurred during the frst 10–20 days after the NRE. The major contributors to the absorbed dose in this period were short-lived radionuclides.

Radiation damage to agricultural animals was largely caused by the accumulation of various radioiodine isotopes in the thyroid. In the frst 240 days after the NRE, the ratio of absorbed doses from all sources of exposure between the thyroid, GI tract mucosa and whole body was 230:1.2:1 (Alexakhin et al. 1992).

Doses received by farm animals depended on the deposition density of radionuclides at their locations and their residence time in the contaminated regions. Doses to the GI tract mucosa in a few cattle grazing in the 30 km zone reached 10 Gy over the frst month after the NRE. The doses were about 7 Gy to tens of thousands of evacuated animals and about 1 Gy in the remaining livestock (Alexakhin et al. 2004). There was a 69% and 82% reduction in thyroid function in cattle associated with an estimated thyroid dose of 50 Gy and 280 Gy, respectively (Astasheva et al. 1991).

Animals that remained in the exclusion zone for several months had impaired immune responses, lowered body temperatures and cardiovascular disorders. Increased lethality was observed in evacuated cows 5–8 months after the NRE. Damage included partial atrophy or total destruction of the thyroid, liver degeneration, increased amount of visceral fat, gall bladder and spleen enlargement and myocardium dystrophy (Alexakhin et al. 2004).

Changes in the concentration of thyroid hormones and adenylyl cyclase activity in cattle in the frst year after the NRE were reversible. This response indicated that there was a compensatory mechanism for the activation of cyclic AMP system in animals with reduced secretion of thyroid hormones in case of thyroid damage (Shevchenko et al. 1990). Concentrations of thyroid hormone were also low during lactation.

The offspring of exposed cows had reduced live weight, but reproductive capacity returned to normal by 1989 (Astasheva et al. 1991). There was no evidence of an increased occurrence of congenital malformations in offspring of cows that were evacuated from the 30 km zone.

The severity of radiation damage to the thyroid was linked with the stable iodine content in the animal's diet. In sheep from the Belarusian Poliessie, a reduced level of iodine nutrition (that commonly occurred in this area) led to the thyroid accumulating a relatively large proportion of the absorbed radioiodine and 2–2.5-fold higher doses to the thyroid than in controls (Budarkov et al. 1992).

Five months after the Chernobyl NRE, many sheep evacuated from the 30 km zone developed serious haematological alterations in the peripheral circulation (Alexakhin et al. 2004). Leucopenia was reported in 89% of animals and lymphopenia in 90%. Also 54% of sheep exhibited initial and marked anaemia and 34% had serious inhibition of haemopoiesis. Offspring of highly exposed cows had reduced weight, decreased daily live weight gains and disruptions to their hormonal status (Astasheva et al. 1991). Reproduction returned to normal in the spring of 1989. No valid data on an increased occurrence of teratogenesis in offspring of the evacuated from the 30 km zone animals was recorded.

Chronic radiation damage was still detected in sheep and horses that had been in a highly contaminated area nearly 2 years after they had been removed. They were generally in poor condition and emaciated and had decreased thyroid hormone levels.

## **5.8 Routes of Radionuclide Intake via Aquatic Pathways**

Radionuclides released after a NRE enter the aquatic environment via a number of routes. When released into the atmosphere, radionuclides will be deposited onto catchments from which there will be an initial transfer through the catchment via runoff, especially if deposition is associated with rainfall, into streams and rivers which will ultimately be discharged into coastal and open ocean marine systems. After the initial period of radionuclide deposition during the emergency response phase, subsequent transfer from catchments occurs through processes such as runoff, erosion, decontamination activities and forestry practices. The rate of loss of radionuclides from catchments may also be enhanced during heavy rainfall events such as typhoons.

After the Chernobyl NRE, long-lived 137Cs and 90Sr formed the major component of contamination of aquatic ecosystems. Fractions of many radionuclides in sediments in aquatic environments may remain in mobile (or exchangeable) states and may transfer from the sediment compartment to the water column (Boyer et al. 2018). The fraction of a particular radionuclide present in these exchangeable phases will depend on numerous factors including, amongst others, the sediment or soil characteristics, the presence of competing ions, pH and redox conditions.

During the frst few weeks after the NRE, activity concentrations in river waters rapidly decline, because of the physical decay of short-lived isotopes and as radionuclide deposits gradually became absorbed to soils and bottom sediments. In rivers, due to the constant throughfow of water, there is less contamination in the longer term, since contaminated upper layers of bottom sediments tend to be replaced, particularly in food conditions.

The reduction in 90Sr and 137Cs activity concentrations occurred at a similar rate for different rivers in the vicinity of Chernobyl and in rivers in Western Europe (Monte 1995). In small catchments, highly organic soils such as saturated peat soils released up to an order of magnitude more radiocaesium to surface waters than occurred where there were mineral soils present (Smith et al. 2004).

In some lakes radiocaesium activity concentrations in water remained relatively high due to continuing inputs of runoff from organic soils in the catchment. In addition, internal cycling of radiocaesium in lakes with little infow and outfow of water led to much higher activity concentrations in their water and aquatic biota than were typically seen in open lakes and rivers with higher amounts of water infow and outfow. Radionuclide activity concentrations in water declined rapidly in reservoirs and lakes with signifcant infow and outfow of water.

Radionuclides deposited onto lakes or reservoirs are also removed from the water by the sedimentation of particulate material, leading to the long-term removal of radionuclides from the surface layers to bottom sediments. Radiocaesium activity concentrations in lakes decline relatively rapidly during the frst months after fallout followed by slower declines over a period of years as radiocaesium became more strongly absorbed to soils and river bed sediments.

In lakes where the radiocaesium originated from organic soil catchments, the contamination was approximately an order of magnitude higher than in nearby lakes with mineral soil catchments (Hilton et al. 1993). Some lakes in Western Europe with organic catchments had radiocaesium activity concentrations in water and fsh that were similar to those in some lakes in the more highly contaminated areas in Ukraine and Belarus. Long-term contamination can also be caused by remobilization of radionuclides from bed sediments. In shallow "closed" lakes where there were no signifcant surface infow and outfow of water, the bed sediments played a major role in determining radionuclide activity concentration in the water.

## *5.8.1 Radionuclides in Freshwater Fish*

The principal route of accumulation of radionuclides for aquatic animals is via food, but some radionuclides can be directly absorbed from the water. Radionuclide uptake from freshwater is infuenced by the ambient chemistry.

Radionuclide activity concentrations in fsh vary considerably in different species and depend on physiological features such as mass, dietary preferences and preferred habitat within the water column.

There are only limited data on uptake of 131I in fsh. After the Chernobyl NRE, 131I was rapidly absorbed by fsh reaching as high as 6000 Bq/kg fw soon after the contamination of water bodies but within approximately 1 month fell to only 50 Bq/ kg fw (IAEA 2006a). This represents a rate of decline similar to that of its physical decay. The 131I activity concentrations in fsh became insignifcant a few months after the NRE.

There have been many studies on radiocaesium contamination of freshwater fsh. Because of its chemical similarity to caesium, the potassium concentration of lake or river water infuences the rate of accumulation of radiocaesium in fsh. Strong inverse relationships were reported between the potassium concentration in water and that of 137Cs in fsh (Smith et al. 2002). Bioaccumulation factors in lakes with low potassium concentrations could be one order of magnitude higher than that in lakes with high potassium concentration. Thus, fsh from lakes in agricultural areas where runoff of potassium fertilizer is signifcant had lower bioaccumulation factors than fsh from lakes in seminatural areas (Smith et al. 2002).

After the Chernobyl NRE, the accumulation of radiocaesium resulted in activity concentrations in some fsh that were above intervention levels for consumption. The elevated levels persisted for many years in some areas in both the most affected regions of the USSR and parts of Western Europe (Jonsson et al. 1999).

There are relatively high transfer and retention of radiocaesium by some fsh species, despite low radiocaesium activity concentrations in water. Uptake of radiocaesium in small fsh was relatively rapid, with the maximum activity concentrations occurring a few weeks after a NRE (Jonsson et al. 1999; Zibold et al. 2002). Due to the slower uptake rates of radiocaesium in large predatory fsh (e.g. pike, eel), maximum activity concentrations took up to a year after the NRE to be established.

In shallow closed lakes, 137Cs activity concentrations in fsh declined slowly in comparison with fsh in rivers and open lake systems, due to the slow decline in radionuclide activity concentrations noted above. In the long term, 137Cs activity concentrations in predatory fsh were signifcantly higher than non-predatory fsh, and large fsh tended to have higher activity concentrations than small. The increase in activity concentration in large fsh is termed the "size effect" and is due to metabolic and dietary differences. Radiocaesium activity concentration in large predatory fsh could be fve to ten times higher than in non-predatory fsh.

After the Chernobyl NRE, there was a focus on collecting data for radiocaesium from some of the many lakes in Finland. The concentration of 137Cs in pike tissues peaked after only 2 years. Over a 10-year study period, the *T eff* 1 2/ of strontium was 15 years for pike and perch and 9 years for vendace (Saxen 2004). However, sitespecifc characteristics of the lakes led to considerable variation in *T eff* 1 2/ in individual lakes ranging from 7 to 29 years for pike, 11 to 30 years for perch and 7 to 11 years for vendace. Activity concentrations of 137Cs in 20 different species of fsh varied considerably even 15 years after initial contamination, ranging from 16 to 6400 Bq/ kg (Saxén and Sundell 2006).

In a contaminated, closed lake in Russia, the 137Cs activity concentration was two orders of magnitude higher than in fsh in rivers or fow-through lakes in the same region (Travnikova et al. 2004).

Chernobyl fallout 90Sr entered water courses via runoff and remained in the water phase rather than depositing in sediments as rapidly as 137Cs (Outola et al. 2009). Nevertheless, 90Sr activity concentrations in fsh in Finland were much lower than those of 137Cs. Stable strontium and 90Sr behave in a similar chemical and biological manner to calcium in freshwater systems. The 90Sr activity concentration in fsh depended on the water chemistry with higher accumulation associated with (i) low calcium concentration in the water (i.e. "soft water") and (ii) low electrical conductivity. Radiostrontium accumulated in calcium-containing organs such as the skin, bones, fns and head of the fsh (Kaglyan et al. 2008). Depending on the pattern of deposition of radioactive fallout, there were differences in the concentrations in fsh from different lakes. In 15 lakes the average 90Sr activity concentration in fsh muscle was 20 and 60 times higher, respectively, in vendace (a non-predator species) and perch (mixed habit) than in pike (a predator). After the initial deposition from Chernobyl, it took 3 years for 90Sr activity concentrations to reach a peak in pike. After this, concentrations decreased sharply to pre-Chernobyl levels. In contrast, in non-predatory vendace, 90Sr activity concentrations were highest 1–2 years after contamination (Outola et al. 2009).

## **5.9 The Risk for Public Health (Placement on the Market for Human Consumption)**

## *5.9.1 Radioiodine*

After the onset of the NRE, the most immediate and important potential source of internal exposure to radioactivity is the short-lived radioiodine isotopes such as 131I. Radioactive caesium (134Cs and 137Cs), in contrast to radioactive iodine, has a long half-life (134Cs, 2 years; 137Cs, 30 years).

The role of iodine in human health and the importance of iodine sources have been reviewed by Fuge and Johnson (2015); some of the main points from the review are briefy described here. Iodine is an essential element in the human diet, and a defciency can lead to a number of health outcomes collectively termed iodine defciency disorders (IDD). Human intake of iodine is mainly from food with some populations also obtaining appreciable quantities of iodine from drinking water. Plant-derived dietary iodine is generally insuffcient alone. Seafood is an important source of iodine, but other inputs are mainly from sources such as the use of iodized salt and dairy produce.

Radioactive iodine (particularly 131I) in food is of immediate concern due to its rapid transfer to milk from contaminated feed and its accumulation in the thyroid gland. I-131 has a relatively short half-life (8 days), so it will naturally decay over a short time frame. If radioactive iodine is breathed in or swallowed, it will concentrate in the thyroid gland and increase the risk of thyroid cancer.

The uptake of radioactive iodine into the thyroid gland can be decreased or prevented by ingestion of stable iodine in the form of potassium iodide pills. Once the thyroid is saturated with iodine, no further iodine can be incorporated. Iodized table salt should not be used as an alternative to potassium iodide pills as it does not contain suffcient iodine to saturate the thyroid. Furthermore, high salt intake may have adverse health effects.

After the Chernobyl NRE, the 131I activity concentrations in milk were particularly high in privately owned dairy cows which were grazing forest clearings and unimproved land in contaminated areas. Initially, information regarding the need to stop the cows grazing such pasture, and to avoid consuming the milk, was less effective for subsistence households. Consequently, people in these households received relatively high radioiodine doses, leading to elevated rates of thyroid cancers in these areas (IAEA 2006a, b). The impact of 131I consumption was enhanced by the defciency of iodine in the diet of some of the more contaminated areas around the NPP.

## *5.9.2 Radiocaesium*

In contrast to short-lived radioiodine isotopes, radiocaesium (134Cs and 137Cs) has a long half-life (134Cs, 2 years; 137Cs, 30 years).

Over time, radiocaesium can be accumulated in various terrestrial animals, or into rivers, lakes and the sea where fsh and other seafood could take up the radionuclides. Animal products from the wild, such as game meat, may continue to be a radiological problem for a long time. Fish and aquatic microfora may bioconcentrate certain radionuclides, but due to the high dilution of radionuclides in water, contamination tends to be confned relatively locally.

Radiocaesium can stay in the environment for many years and could continue to present a long-term problem for food, and food production, and as a threat to human health. If radiocaesium enters the body, it is distributed uniformly throughout the body's soft tissues, resulting in exposure of those tissues. Compared to some other radionuclides, 137Cs remains in the body for a relatively short time.

## *5.9.3 Other Radionuclides*

Other radionuclides could be of concern, depending on the nature of the NRE and release of specifc isotopes.

## **References**


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## **Chapter 6 Management Options for Animal Production Systems: Which Ones to Choose in the Event of a Nuclear or Radiological Emergency?**

**Anne Nisbet**

## **6.1 Introduction**

If radionuclides are released into a rural area as a result of a NRE, precautionary advice, including food restrictions, will be issued for places where permitted levels of radioactivity in food may be exceeded. The aim is to minimize the risk of people consuming contaminated food. Within few days, preliminary monitoring data may be available to help inform decisions on whether statutory food restrictions are required. These restrictions identify specifc areas where activity concentrations of one or more radionuclides exceed OILs in foodstuffs. The areas subject to food restrictions may be large, and for some long-lived radionuclides, there is potential for a wide range of food production systems to be disrupted for many years, unless some form of intervention is undertaken. The implementation of management options is one form of protective action that will reduce the activity concentrations of radionuclides in foodstuffs to below OILs, thereby providing reassurance to consumers and sustaining production and livelihoods.

## **6.2 Management Options**

Actions intended to reduce or avert radioactive contamination of agricultural products before they reach consumers have previously been referred to as agricultural countermeasures (IAEA 1994). The term 'countermeasure', although widely encountered, is often perceived by stakeholders as being a rather negative action (Nisbet et al. 2005). The term 'management option' has therefore tended to be used

© The Author(s) 2021 107

A. Nisbet (\*)

Public Health England, Centre for Radiation, Chemical & Environmental Hazards, Oxon, UK e-mail: Anne.Nisbet@phe.gov.uk

I. Naletoski et al. (eds.), *Nuclear and Radiological Emergencies in Animal Production Systems, Preparedness, Response and Recovery*, https://doi.org/10.1007/978-3-662-63021-1\_6

in recent years to encompass interventions aimed at reducing or averting contamination, or the likelihood of contamination, of food production systems. They are applied across all phases of the emergency timeline.

A large number of management options for use in intensive livestock production, backyard farms and free-ranging animals have been developed since the NRE at the Chernobyl NPP. Some of these options have been adapted and improved for sitespecifc conditions following the NRE at the Fukushima Daiichi NPP (NEA 2018). To capture relevant information about these management options and record it systematically, a datasheet template was designed (Nisbet et al. 2015). It takes into account criteria that decision-makers might wish to consider when evaluating different management options. A shortened version of the template has been used for the purposes of this book to provide some generic information on the management options that are applicable to animal production systems. This datasheet template can be found in Annex A, Table A1.

Management options can be implemented at different phases following the NRE, from pre-deposition (when there is a threat of release), through the urgent and early phase and into the late phase. Furthermore, the options can be targeted at specifc radionuclides or particular contamination pathways, for example, the transfer from pasture to milk and meat, and during the processing of animal products.

Pre-deposition options, as their name suggests, are actions that need to be implemented prior to the deposition. They prevent radionuclides reaching food products by, for example, the closing of air intake systems at food processing plants, the covering of harvested fodder crops and the sheltering of livestock. These options are radionuclide-independent.

Other management options are implemented when the release of radionuclides to the environment has stopped. These options work by either targeting the live animal or one or more animal-derived food products. Options directed at live animals fall into two main categories: those that involve a change in husbandry practice (e.g. provision of uncontaminated feed) and are radionuclide-independent and those that require the use of additives to prevent or reduce the uptake of specifc radionuclides into animals (e.g. Prussian blue to reduce gut uptake of radiocaesium). Live monitoring is useful in providing reassurance to consumers that contaminated produce is not entering the food chain. In situations where it is not possible to adequately reduce concentrations of radionuclides in live animals, slaughter (also known as culling) followed by disposal must be considered as a last-resort option. To reduce the quantities of waste, processing of contaminated animal products followed by storage (e.g. salting of meat, and cheese or butter production) can be effective at reducing radionuclides to levels below the OILs.

Many management options are of a technical nature involving some form of physical or chemical intervention to reduce transfer of radionuclides in the food chain. Other management options can be considered to have more societal relevance. These include support for self-help measures by local provision of monitoring equipment and the raising of intervention levels for animal products to maintain traditional farming practices and ways of life.

The placing of statutory restrictions on the marketing of animal products can generate considerable volumes of contaminated biodegradable waste. Appropriate routes of disposal need to be identifed, ideally in advance of a NRE. There are many types of disposal routes that can be considered, ranging from relatively simple in situ methods (e.g. landspreading of milk) to offsite commercial treatment facilities (e.g. incineration of animal carcasses).

Table 6.1 provides an alphabetical list of all the management options considered in this chapter. A distinction is made between options directed at live animals and options directed at animal products. There is also an additional category listing options for disposing of waste produce. Datasheets for these management options


**Table 6.1** Management options for animal production systems

a AFCF is also known as Prussian blue can be found in Annex A, based on published information for the UK (Nisbet et al. 2015) and Europe (Nisbet et al. 2009). The datasheets have been shortened and adapted where relevant to backyard production.

## **6.3 Radionuclides of Importance**

During an NRE a mix of radionuclides will be released. The mix depends on both the type of source and the nature of the NRE. However, generally, 134Cs, 137Cs and 131I are of particular interest because of their likelihood of release and subsequent impact on people. This can be due to external exposure from inhabited surfaces (which is dominated by caesium isotopes) or ingestion of contaminated food products (where exposure is dominated by caesium and iodine isotopes). In food production systems, radioiodine tends to cause severe short-term problems, whilst radiocaesium has a longer-term impact. Both radionuclides had a signifcant radiological impact following the NPP NREs at Chernobyl and Fukushima Daiichi. There are other types of NREs (e.g. transport accidents and fres at sites holding radioactive materials) that have the potential to release a wider range of radionuclides into the environment. The most important radionuclides considered to pose a threat to food production systems are 89Sr, 90Sr, 131I, 134Cs, 137Cs, 238Pu and 241Am.

## **6.4 Seasonality and Radioecological Zoning**

The seasons of the year when deposition occurs can have a signifcant infuence on contamination levels in animals and animal products and hence the management strategy adopted. This is particularly the case for MS that house livestock for part or all of the year and provide stored feed. This can lead to seasonal variations in radionuclide concentrations in milk and meat (by up to three orders of magnitude) according to the timing of when (or if) animals are fed contaminated feed or return to contaminated pasture with respect to timing of deposition.

## **6.5 Decision-Aiding Handbooks for Food Production Systems**

In advance of a NRE, decision-makers will need to be in a position to construct a strategy for managing contaminated animal production systems. For small-scale, single radionuclide releases, the strategy may comprise one or two management options that could be applied over the frst few days or weeks following the NRE. For wide-scale releases of multiple radionuclides, a management strategy is likely to be more complex, comprising a series of management options that could be implemented over different phases of emergency response and affecting several types of production system.

The selection of individual options depends on a wide range of criteria including effectiveness, technical feasibility, impact (e.g. agricultural, environmental and societal) and cost. For any one NRE scenario, only a subset of options will be applicable. However, as each NRE will be different in terms of its radiological composition and impact on the food chain, it is not possible to establish a generic strategy. Consequently, handbooks for food production systems (as well as inhabited areas and drinking water supplies) were developed in close collaboration with stakeholders to aid decision-makers in the selection and combining of management options in the UK (Nisbet et al. 2015) and Europe (Nisbet et al. 2009). The handbooks can be used in emergency response, or as a preparatory tool, under noncrisis conditions, to engage stakeholders and to develop local and regional plans. In addition, the handbooks are useful for training purposes and for application during emergency exercises.

The handbook for food production systems contains an eight-step decisionaiding framework. This comprises various look-up tables aimed at helping those developing the recovery strategy to progressively evaluate the options and eliminate those deemed unsuitable. This informs the decision-making process and provides a short list of options. The datasheets can then be used to provide important supporting information on, for example, effectiveness, feasibility, waste generation and cost.

## *6.5.1 Decision-Aiding Framework*

The eight-step decision-aiding process to support the management of contaminated animal production systems is summarized below.


Further guidance on each of the steps is provided in the following subsections.

## *6.5.2 Selection Tables (Step 2)*

Color-coded selection tables are presented for milk (Table 6.2) and meat (Table 6.3). These selection tables provide:



**Table 6.2** Selection table of management options for maintaining production of milk


**Table 6.3** Selection table of management options for maintaining production of meat


The classifcation used in the selection tables is intended to be a guide and requires customization at local or regional level by the relevant stakeholders.


So, for milk, the optimum strategy might be as follows:

a Clean feeding involves the provision of uncontaminated or less contaminated feed

## *6.5.3 Applicability of Management Options for Different Radionuclides (Step 3)*

Most of the information that is available on management options relates to radioactive isotopes of iodine and caesium due to the importance of their radiological impact in previous NREs. For the other radionuclides considered, there are few data to indicate whether a particular management option is applicable or not. Nevertheless, these radionuclides have certain characteristics in terms of their physical half-life, chemical form, mobility in soil and photon energy as well as other characteristics that will give a guide as to whether an option should be considered or eliminated.

Table 6.4 indicates whether a management option is likely to be applicable or not according to radionuclide. An option is considered to be applicable if:


The category of 'not applicable' is attributed to an option if:



**Table 6.4** Applicability of management options for different radionuclides

#### **Key:**

Half-life: d = days, y = years

✓: Selected as target radionuclide (i.e. known or probable applicability)

a: Management option specifc for Cs

b: Management option specifc for radionuclides in Group II of periodic table

c: Comparatively short physical half-life of radionuclide relative to timescale of implementation of the management option

d: No/low photon energy of radionuclide makes detection diffcult

e: Radionuclide has low feed-to-meat or milk transfer, making radical management options inappropriate

f: Low soil-to-plant transfer makes radical management option inappropriate

g: Management option only effective for short-lived radionuclides

Table 6.5 indicates whether a waste disposal option is likely to be applicable or not according to radionuclide. Five criteria were used to assess applicability:



**Table 6.5** Applicability of waste disposal options for different radionuclides

#### **Key:**

Half-life: d = days, y = years

✓: Selected as target radionuclide (i.e. known or probable applicability)

a: Not recommended due to the potential rapid movement of the radionuclide in the ground after burial, taken to be represented by a soil mobility (Kd) of between 0 and 30

b: Not recommended due to comparatively short physical half-life of radionuclide relative to timescale of implementation of the management option

c: Not recommended due to the potential for the radionuclide to concentrate in marine foods, taken to be represented by a concentration ratio in marine foods (fsh, crustaceans and molluscs) of 1000 or more

d: Not recommended as boiling temperature is below temperature of option. Volatilization may occur

# : Nuclides placed or deposited onto surface layers of soil – only plant uptake is considered

† : Nuclides are considered to be buried under clean soil – only mobility is considered

‡ : Maximum temperature at which option is carried out. Operating temperature is typically 850–1100 °C and usually 900 °C

¶ : Maximum temperature at which option is carried out, typically between 100 and 145 °C

## *6.5.4 Key Constraints Affecting Management Options (Step 4)*

Management options invariably have some constraints associated with their implementation. To assist in eliminating unsuitable options, major constraints for each option are presented in Table 6.6 taking into account technical feasibility and capacity, timescales for implementation, waste generation and societal needs. If a major constraint is identifed, it does not necessarily indicate that the management option should be eliminated but does raise awareness of specifc issues that need to be overcome.


**Table 6.6** Key constraints for each management option


**Table 6.6** (continued)

#### **6.5.4.1 Technical Feasibility and Capacity**

An option is considered to be technically feasible if the equipment, techniques and resources required to implement it are available in the affected area or can be obtained from outside the area in suffcient number. The capacity of or scale on which an option can be implemented is determined by available manpower, work rates for equipment and restrictions in minimum or maximum areas of land or volumes of material that can be treated.

#### **6.5.4.2 Timescales for Implementation**

Selection of management options should take into account time-related aspects (e.g. when the NRE happened, the elapsed time, temporal variation in activity concentrations of radionuclides in the environment and their movement through the food chain). In the case of rapidly developing NREs, alerts are only given after the release has started. If the alert comes too late, it will not be possible to implement predeposition options such as the sheltering of dairy animals. For some options, the time of year that the NRE takes place can affect applicability, for example, clean feeding is constrained by the availability of stored clean feed, which tends to be lowest at the start of the growing season. Other options such as incorporation of dietary additives into animal feed or boli take time to organize and prepare, so would not necessarily be available in the urgent phase.

#### **6.5.4.3 Waste Generation**

It is not just the placing of restrictions on foodstuffs or product recall that creates wastes. Several management options also produce contaminated by-products (e.g. slaughtering of dairy cows, processing of milk and meat), and routes for their disposal must be considered at the point at which the option is selected. The following criteria are important when selecting disposal routes:


Disposal routes for contaminated milk include landspreading, anaerobic digestion, discharge through long sea outfalls and incineration. Options for animal carcasses and meat include burial, burning, incineration and landfll.

#### **6.5.4.4 Environmental Impact**

Management options can have positive or negative and direct or indirect impacts on the environment. Direct environmental impacts can include changes in biodiversity from changes in grazing pressure brought about by selective grazing and manipulation of slaughtering times. Pollution of watercourses can occur due to inappropriate landspreading of milk. Indirect effects on the environment can happen, for example, when an individual freedom's is reduced by changes to traditional lifestyles, e.g. restrictions on hunting.

#### **6.5.4.5 Cost**

It is very diffcult to predict the economic cost of implementing management options because of the numerous factors that infuence cost. There are direct costs, such as costs linked to lost production, costs from the implementation of options (labour, equipment, consumables, transport, etc.) and costs from the handling of wastes. Indirect costs include those incurred through the impact on the environment and tourism and loss of market share. The magnitude of these direct and indirect costs will depend on many factors such as the time of year of the NRE. NREs occurring at the start of the growing season have larger consequences for food production systems than those occurring after harvest. Also, relevant is the period of time over which a management option is implemented and the scale of the NRE, as costs are proportional to the area of land affected and the type of land use. Costs for remediating intensive agricultural production are likely to be higher than for small-scale production systems.

## *6.5.5 Effectiveness of Management Options (Step 5)*

The primary aim of many of the management options considered for food production systems is to reduce doses from the consumption of contaminated foodstuffs. Options will be chosen if they reduce activity concentrations in milk and meat to below OILs. Effectiveness is infuenced by both technical and societal criteria (e.g. application rates, duration of treatments, physical and chemical form of the radionuclide in the environment, biological half-live, timeliness of implementation and compliance in implementation). They will vary therefore according to the prevailing circumstances. Some management options are included as supporting measures (e.g. live monitoring) and do not reduce doses in their own right but provide valuable reassurance.

Experimental work and feld-based studies in the regions affected by the NREs such as Chernobyl and Fukushima Daiichi have enabled the effectiveness of various management options to be assessed under feld conditions. Effectiveness is generally expressed as percentage reduction in activity concentration in the target medium (food product) following implementation of a management option. Table 6.7 provides a look-up table on the typical effectiveness of management options for a range of radionuclides and animal products. More detailed information on effectiveness is provided in the datasheets (Annex A).


**Table 6.7** Effectiveness of management options


**Table 6.7** (continued)

## *6.5.6 Management Options Incurring an Additional Dose to Implementers (Step 6)*

Although management options are chosen to reduce doses from ingestion of contaminated produce, additional doses can be received by those responsible for implementing the options, when they are not part of their routine work. These doses are most likely to be received by veterinarians, farmers and those working on the land. Some management options generate secondary wastes that require disposal (e.g. from food restrictions, food processing and the slaughtering of livestock), which may result in workers at waste management facilities receiving additional doses. A number of factors infuence the magnitude of the doses received: radionuclides present, exposure pathways and exposure time. In general, the additional doses received from implementation of management options are trivial. Waste disposal options that concentrate and contain radionuclides are those most likely to incur the largest doses and for which a dose assessment should be carried out. Table 6.8 gives a list of management options for milk and meat, showing whether they result in an additional dose to implementers either directly or through the subsequent generation and management of secondary wastes. Table 6.9


**Table 6.8** Management options incurring additional doses to implementers


**Table 6.9** Additional doses incurred following implementation of waste disposal options

gives a list of waste disposal options, showing whether they result in an additional dose to implementers and members of the public. This information will not necessarily eliminate options but serves to warn the decision-maker that selection of particular options will have implications for wastes and doses, some of which will require further assessment before implementation. It will be important to monitor all locations where disposal of contaminated animal products and carcasses has been carried out.

## *6.5.7 Consideration of the Datasheets (Step 7)*

A subset of options remaining in the selection table after Step 6 are those most likely to be incorporated into the overall management strategy. A closer look at the datasheets contained in Annex A will confrm whether any additional constraints might preclude further options from being considered. This can only be done on a site and incident-specifc basis, according to the prevailing circumstances and in conjunction with all of the relevant stakeholders.

## *6.5.8 Selecting and Combining Options to Develop the Management Strategy (Step 8)*

The management strategy will consist of a number of management options that can be applied either singly or in combination during the pre-deposition phase and/or in the days, weeks, months and even years following the NRE. The strategy is not fxed. It is regularly reviewed and updated according to the effectiveness of the measures, taking into account the views of all the relevant stakeholders. Several hypothetical worked examples have been developed to help illustrate how the decision-aiding framework can be used to select and combine options in the development of a management strategy. These worked examples are presented in Annex B.

## **References**


The opinions expressed in this chapter are those of the author(s) and do not necessarily refect the views of the International Atomic Energy Agency, its Board of Directors, or the countries they represent.

**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 3.0 IGO license (http://creativecommons.org/licenses/by/3.0/igo/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the International Atomic Energy Agency, provide a link to the Creative Commons license and indicate if changes were made.

 Any dispute related to the use of the works of the International Atomic Energy Agency that cannot be settled amicably shall be submitted to arbitration pursuant to the UNCITRAL rules. The use of the International Atomic Energy Agency's name for any purpose other than for attribution, and the use of the International Atomic Energy Agency's logo, shall be subject to a separate written license agreement between the International Atomic Energy Agency and the user and is not authorized as part of this CC-IGO license. Note that the link provided above includes additional terms and conditions of the license.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

## **Chapter 7 Information Systems in Support of the Decision-Making Tools**

**Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture**

Development and dissemination of the information technology throughout the world, as well as the convention potentials for rapid information exchange, primarily via Internet-based platforms, enable for rapid reporting, data collection, data analysis and situation-based decision-making. Such a workfow is especially important in management of rapidly developing emergencies, including NREs. IAEA has already established several such platforms and is intensively working on the improvements and upgrades of the existing ones, as well as on the development of new, sector-specifc information platforms. This chapter gives information on the currently existing/developing IAEA platforms for management of NREs.

## **7.1 The IAEA Unifed System for Information Exchange in Incidents and Emergencies (USIE)**

The IAEA has emergency contact points worldwide that can use various channels to communicate with the agency through its Incident and Emergency Centre (IEC – https://iec.iaea.org/usie/actual/LandingPage.aspx). The Unifed System for Information Exchange in Incidents and Emergencies (USIE) is a secure website maintained by the IAEA to enable countries to exchange urgent notifcations and follow-up information during an emergency.

In an emergency, MS require prompt, authoritative and verifed information about the situation and its potential consequences. The IAEA's IEC maintains a list of emergency contact points in MS, States Party to the Conventions on Early

Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture (\*) Animal Production and Health Section, Vienna, Austria e-mail: i.naletoski@iaea.org

I. Naletoski et al. (eds.), *Nuclear and Radiological Emergencies in Animal Production Systems, Preparedness, Response and Recovery*, https://doi.org/10.1007/978-3-662-63021-1\_7

Notifcation of a Nuclear Accident (IAEA 2002) and on Assistance in the Case of a Nuclear Accident or Radiological Emergency, and in other relevant international organizations. Via the USIE website, as well as by telephone, facsimile, email and video conferencing, the Centre maintains communication with these contact points. The IAEA's Operations Manual for Incident and Emergency Communication (IAEA 2013) outlines the arrangements for emergency communications.

More than 1000 users from over 150 MS are currently registered in USIE. The System not only facilitates the exchange of notifcations and information between countries during an emergency; it also allows them to request information or international assistance. USIE is also used by offcially nominated INES National Offcers, who access it to share information on events rated using the INES (IAEA 2014). While USIE itself is not a public website, information on events obtained from USIE is available publicly on the NEWS website.

To shorten the time needed to share information from national systems to systems used at international level, the IAEA uses the International Radiological Information Exchange data standard (IRIX) as common data standard for information exchange. Developed by the IAEA together with MS and other international organizations, this standard enables the Agency's counterparts to connect their information exchange systems, thereby allowing for an effcient exchange of event details. This is required under the Convention on Early Notifcation of a Nuclear Accident. Details that can be shared using IRIX include information on the status of nuclear installations, releases of radioactive material and radiation levels measured in the environment. The IRIX standard has also been implemented in the USIE system.

## **7.2 Decision Support System for Nuclear Emergencies Affecting Food and Agriculture (DSS4NAFA)**

Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture International Atomic Energy Agency, Vienna, Austria

In the event of a large-scale accident affecting food and agriculture, the management and visualization of data are crucial for effcient response by food and health authorities. Traditional collection and processing of datasets are presently inadequate for large-scale emergency response due to the analogue style of data transfer (often resulting in human errors for data input) and complex decision-making process (data not presented in an intuitive manner) which in turn prevents swift decision-making. However, advancements in information technology systems have allowed for improved real-time management of large volumes of data and optimized decision-making support.

The Soil and Water Management and Crop Nutrition Laboratory, under the Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture, developed the Decision Support System for Nuclear Emergencies Affecting Food and Agriculture

**Fig. 7.1** DSS4NAFA is a cloud-based IT tool that assists in data management and data visualization using state-of-the-art technologies

(DSS4NAFA), to assist decision-makers in responding to large-scale emergencies affecting food and agriculture (Fig. 7.1). The specifc features that set DSS4NAFA apart is its integrated data management, data visualization and decision support capabilities that assist in overcoming the logistical challenges encountered in a nuclear emergency. The modules in DSS4NAFA supports the logistical assignments of sample collection from the feld, sample analysis in the lab, resource optimization and allocation as well as decision support through scenario forecasting. As the system was built such that the data called and time frames set can be customized, the DSS4NAFA system can be used both for nuclear and non-nuclear, routine monitoring and emergency response.

The system platform is accessible on-site through a smartphone application, or via a desktop interface, allowing for streamlined usage and communications. Through the mobile app, which samplers use during the data collection phase, DSS4NAFA allows for reduced human errors and increased information processing speed in the feld and lab. Upon obtaining the radionuclide concentration data, the food restriction dashboard collates the information, including the spatial distribution and time resolution of the accident, and suggests food and planting restrictions based on the level of risk and the specifed tolerance levels. The use of DSS4NAFA reduces the complexity in managing logistics of data collection, forecasting scenarios in data analysis and proposing restriction actions for decision-making support. The combination of these functionalities brings together all stakeholders in the process and increases robust emergency response capabilities.

The DSS4NAFA system was built using open-source tools such as the Ruby on Rails web application framework, the PostgreSQL/PostGIS database system, the PhoneGap/Cordova framework, the Bootstrap User Interface library and the D3 and MapBox leafet libraries. A video providing an overview of the DSS4NAFA system is available online at https://youtu.be/Ut4GzjKabMc.

## **7.3 iVetNet**

iVetNet is an online information platform, developed by the Animal Production and Health Section of the Joint FAO/IAEA Division. The platform is still under development and is composed of multiple modules for support of veterinary entities (primarily laboratories) in information management (sharing of standardized operational procedures, SOPs), support in the development, implementation and maintenance of ISO 17025 standard and exchange of professional experiences among the members of the Veterinary Laboratory (VETLAB) network.

The core of iVetNet is the module of competent entities and staff members, attributed with different categorizations, aimed to easily identify institutions/persons competent for management of specifc problems of veterinary importance. These include disease diagnosis, management of outbreaks, implementation of disease contingency plans as well as management of emergencies affecting animal production systems, such as the NREs.

The module for exchange of validated SOPs is subdivided into categories, such as procedures for disease detection, vector capturing and identifcation, procedures for support of ISO 17025 standard (equipment maintenance, staff management, etc.) as well as procedures for response to nuclear emergencies (the management options of this manuscript).

Validated and verifed SOPs are shared among the registered users of iVetNet and are permanently available for implementation in their environment. All the procedures, including those aimed for response to NREs, are aimed for integration in the national contingency plans of the veterinary authorities in member states.

Currently iVetNet operates with 112 trial users in 45 member states, most of which (33) are in Africa. The aim of the trial group is to perform "feld testing" of iVetNet, identify of gaps and propose improvement measures.

## **References**


The opinions expressed in this chapter are those of the author(s) and do not necessarily refect the views of the International Atomic Energy Agency, its Board of Directors, or the countries they represent.

**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 3.0 IGO license (http://creativecommons.org/licenses/by/3.0/igo/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the International Atomic Energy Agency, provide a link to the Creative Commons license and indicate if changes were made.

 Any dispute related to the use of the works of the International Atomic Energy Agency that cannot be settled amicably shall be submitted to arbitration pursuant to the UNCITRAL rules. The use of the International Atomic Energy Agency's name for any purpose other than for attribution, and the use of the International Atomic Energy Agency's logo, shall be subject to a separate written license agreement between the International Atomic Energy Agency and the user and is not authorized as part of this CC-IGO license. Note that the link provided above includes additional terms and conditions of the license.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

## **Annexes**

## **Annex A: Datasheets on the Management Options**

#### Anne Nisbet

The list of management options applicable for the animal production systems, as well as their categorisation, is shown in Table 6.1. This annex is presenting the details for each management option, into a standardised datasheet template (Table A1).


**Table A1** Datasheet template (Adapted from Nisbet et al. 2015)










138







**Table A1** (continued)




**Table A1** (continued)








147








**10 Suppression of lactation before slaughter**







**13 Addition of clay minerals to feed**
















**Table A1** (continued)




**Table A1** (continued)




**Table A1** (continued)


**Table A1** (continued)






**Table A1** (continued)













**Table A1** (continued)






**Table A1** (continued)






**Table A1** (continued)





**Table A1** (continued)

Copyright notices for all datasheets listed above – contains public sector information licensed under the Open Government Licence v3.0. The datasheets are open source, and no specifc permission is required to use them, but the source should be acknowledged, and it can only be used for non-commercial purposes

## **Annex B: Worked Examples to Illustrate Decision-Aiding Framework**

#### Anne Nisbet

Several hypothetical work examples have been developed to help illustrate how the decision-aiding framework can be used to select and combine options in the development of a management strategy. The examples are as follows:


The examples take users, in a very general way, through the main decision steps and the types of issues that they would need to address in the development of a recovery strategy. It is important to note that the worked examples provided are only illustrative. They have been included solely to support training in the use of the decision framework. The worked examples should not be used as defnitive solutions to the contamination scenario selected.




Table 6.6 provides information on the key constraints for each option Options to be implemented before arrival of the plume (i.e. short-term sheltering of dairy animals, closing air intake systems at processing factories) depend on the period of notifcation given. For most foreseeable future NREs, some form of early notifcation of a possible release would be expected. This makes the implementation of pre-deposition options more likely, especially at increasing distances from the site of the NRE. Constraints such as availability of suitable housing and supplies of alternative clean feeds for the short-term sheltering and subsequent clean feeding of livestock are unlikely to be signifcant in the autumn, as stored clean feed, harvested earlier in the year, would be available. Restrictions on the entry of milk into the food chain are based on statutory food restriction orders and will be legally binding, irrespective of any constraints. Where there is uncertainty that contaminated milk products may have entered the food chain before restrictions had been put in place, product recall is a possible option; both these options require plans for subsequent management of waste milk. Dilution of contaminated milk with clean supplies, and the processing and storage of milk products prior to consumption, while being technically feasible, may undermine consumer confdence In terms of disposal options, biological treatment facilities have very limited capacity for milk and would not be able to provide a major disposal route in this particular scenario. Furthermore, water utilities may oppose entry of contaminated milk to their sites. Disposal of contaminated milk to sea via long sea outfalls may be possible as a last resort option requiring authorisation from the relevant environmental regulator. For milk held on the farm, landspreading of milk is possible according to the suitability of land. An option that 'buys time' is the processing of milk into powder and its storage for a period until a suitable disposal route is found. The requisitioning of such facilities is likely to be very expensive At this stage, the following management options still need to be considered:


**Table B2** Worked example to illustrate a strategy for caesium contamination of lamb (extensive production)


#### **Table B2** (continued)

#### **4 Refer to look-up tables showing checklists of major constraints for each management option, including those for waste disposal**

Table 6.6 provides information on the key constraints for each option There is only one option to be implemented before arrival of the plume (closing air intake systems at processing factories). For most foreseeable future NREs, some form of early notifcation of a possible release would be expected, making implementation more likely, especially at increasing distances from the site of the NRE Clean feeding is constrained by the availability of alternative clean feeds and suitable areas (either fenced areas or barns) in which to provide a supply of clean feed. It is early in the growing season, so there is unlikely to be any stored feed available. There are no barns in the affected upland areas and the erection of fences is not permitted as it is a national park. This option can be eliminated Live monitoring is constrained by the availability of NaI detectors and trained personnel, which would take time to organise. Live monitoring would therefore be a medium- to long-term option Select alternative land use and slaughtering of livestock (for disposal) is a radical option that should only be considered when all other options have been excluded. As there are alternatives, these options can be eliminated Selective grazing requires the availability of less contaminated pasture nearby. In this case, improved lowland pasture can be found in close proximity to the upland areas; it is already used by farmers to 'fnish' the lambs over a 4-week period prior to the lambs being sent to market The administration of AFCF boli to ruminants and the distribution of AFCF salt licks in the upland areas require a supply of AFCF boli and AFCF salt licks, which would not be readily available and take time to manufacture. This would be a medium- to long-term option Restrictions on the entry of contaminated lamb into the food chain are based on statutory food restriction orders and will be legally binding, irrespective of any constraints. Where there is uncertainty that contaminated lamb products may have entered the food chain before restrictions had been put in place, product recall is a possible option In situations where unique traditional lifestyles need to be protected, a special case for raising intervention levels to above those dictated by statutory restrictions can be considered. This would only be appropriate in the absence of other management options, so it is unnecessary in this scenario Similarly, the salting of meat to reduce activity concentrations of 134Cs and 137Cs to below OILs can be considered when other options for reducing contamination in live animals are not possible. This is not necessary in this scenario Provided management options such as selective grazing and live monitoring are put in

place, there should not be large volumes of sheep or lamb meat requiring disposal Burial of carcasses depends on the availability and suitability of land for the construction of a purpose-built burial pit

Rendering and landfll depend on availability of facilities in the area and capacity of the landfll to take biodegradable material

At this stage, the following management options still need to be considered:




**Table B3** Worked example to illustrate a strategy for iodine and caesium contamination of poultry (backyard production)


management options could be eliminated, either because they are specifc for caesium or strontium or because they are unsuitable for radionuclides with short physical half-lives. However, as 134Cs and 137Cs are also involved in contamination of meat in this scenario, only 3 options can be eliminated: addition of calcium to feed (strontium only); burning of carcasses; and incineration of carcasses (volatilisation of 131I**,** 134Cs, 137Cs and release to the environment)

#### **Table B3** (continued)

#### **4 Refer to look-up tables showing checklists of major constraints for each management option, including those for waste disposal**

Table 6.6 provides information on the key constraints for each option Clean feeding not only depends on the availability of alternative supplies of clean feed but also on suitable housing to prevent the animals going outside and ingesting contaminated feed, vegetation and soil. Manipulating slaughter times by prolonging slaughter may be possible if housing and clean feed is available. As the NRE occurred at the end of the growing season, it is likely that alternative clean feed would be available to support prolonging slaughter

The addition of AFCF to feed reduces the gut uptake of any caesium present in the diet. However, it is likely that AFCF will not be immediately available for incorporation into feed, so this should be considered as a later option

The selection of an alternative land use and slaughtering (culling) of poultry (for disposal) only need to be considered if there are no other viable options for reducing contamination in the live animals or meat products. This is unlikely to be situation in this scenario as both clean feeding, manipulation of slaughter times and addition of AFCF to feed are viable alternatives

Restrictions on the entry of contaminated poultry into the food chain are based on statutory food restriction orders and will be legally binding, irrespective of any constraints. Where there is uncertainty that contaminated poultry products may have entered the food chain before restrictions had been put in place, product recall is a possible option

Where poultry is for home consumption (by the farmer and his/her family), access to/ provision of monitoring equipment to measure radionuclide content in meat can be useful. However, it takes time to obtain monitoring kits and to train personnel, so this should be considered as a later option

The salting of meat can be considered for poultry with activity concentrations of 134Cs and 137Cs above OILs, either on a commercial basis or for home consumption. If carried out commercially, there is a risk of generating mistrust in the food chain. However, if food supplies are limited, this is a viable option

Burial of carcasses depends on the availability and suitability of land for the construction of a purpose-built burial pit

Rendering and landfll depend on availability of facilities in the area and capacity of the landfll to take biodegradable material

At this stage, the following management options still need to be considered:


#### **Table B3** (continued)

