Survey on national practices regarding iodine thyroid blocking in 2016-2017.

Severe nuclear accidents may lead to a release of radioactivity, including radioactive iodine, into the environment. The thyroid gland in the human body needs natural or stable iodine to function properly and this iodine is normally absorbed in small quantities from food. Following a release of radioactive iodine from a nuclear or radiological accident, the body will absorb and accumulate the radioactive iodine in the thyroid gland. This increases the risk of thyroid cancer, especially in children. Since the thyroid gland cannot distinguish between radioactive and stable iodine, stable iodine can be taken to prevent the absorption of radioiodine by the thyroid in the event of a nuclear emergency. This is referred to as Iodine Thyroid Blocking (ITB). In 2017, the World Health Organization published revised guidelines entitled 'Iodine Thyroid Blocking: guidelines for use in planning for and responding to radiological and nuclear emergencies'. The purpose of these guidelines is to support Member States in planning for and implementation of ITB before and during a radiation emergency. To enable the monitoring and measurement of the impact of a specific recommended intervention, a baseline should be established against which the impact will be measured over a certain period of time. With that in mind, a global WHO survey of national policies on ITB was carried out in 2016-2017. Here, an overview of some core findings of this survey is provided.

Public health response and medical management of internal contamination in past radiological or nuclear incidents: A narrative review.

Following a radiological or nuclear emergency, workers, responders and the public may be internally contaminated with radionuclides. Screening, monitoring and assessing any internal contamination and providing necessary medical treatment, especially when a large number of individuals are involved, is challenging. Experience gained and lessons learned from the management of previous incidents would help to identify gaps in knowledge and capabilities on preparedness for and response to radiation emergencies. In this paper, eight large-scale and five workplace radiological and nuclear incidents are reviewed cross 14 technical areas, under the broader topics of emergency preparedness, emergency response and recovery processes. The review findings suggest that 1) new strategies, algorithms and technologies are explored for rapid screening of large populations; 2) exposure assessment and dose estimation in emergency response and dose reconstruction in recovery process are supported by complementary sources of information, including 'citizen science'; 3) surge capacity for monitoring and dose assessment is coordinated through national and international laboratory networks; 4) evidence-based guidelines for medical management and follow-up of internal contamination are urgently needed; 5) mechanisms for international and regional access to medical countermeasures are investigated and implemented; 6) long-term health and medical follow up programs are designed and justified; and 7) capabilities and capacity developed for emergency response are sustained through adequate resource allocation, routine non-emergency use of technical skills in regular exercises, training, and continuous improvement.

GHSI EMERGENCY RADIONUCLIDE BIOASSAY LABORATORY NETWORK - SUMMARY OF THE SECOND EXERCISE.

The Global Health Security Initiative (GHSI) established a laboratory network within the GHSI community to develop collective surge capacity for radionuclide bioassay in response to a radiological or nuclear emergency as a means of enhancing response capability, health outcomes and community resilience. GHSI partners conducted an exercise in collaboration with the WHO Radiation Emergency Medical Preparedness and Assistance Network and the IAEA Response and Assistance Network, to test the participating laboratories (18) for their capabilities in in vitro assay of biological samples, using a urine sample spiked with multiple high-risk radionuclides (90Sr, 106Ru, 137Cs, and 239Pu). Laboratories were required to submit their reports within 72 h following receipt of the sample, using a pre-formatted template, on the procedures, methods and techniques used to identify and quantify the radionuclides in the sample, as well as the bioassay results with a 95% confidence interval. All of the participating laboratories identified and measured all or some of the radionuclides in the sample. However, gaps were identified in both the procedures used to assay multiple radionuclides in one sample, as well as in the methods or techniques used to assay specific radionuclides in urine. Two-third of the participating laboratories had difficulties in determining all the radionuclides in the sample. Results from this exercise indicate that challenges remain with respect to ensuring that results are delivered in a timely, consistent and reliable manner to support medical interventions. Laboratories within the networks are encouraged to work together to develop and maintain collective capabilities and capacity for emergency bioassay, which is an important component of radiation emergency response.

The First Meeting of the WHO Guideline Development Group for the Revision of the WHO 1999 Guidelines for Iodine Thyroid Blocking.

The meeting held in May 2014 in Würzburg, Germany, discussed the scope of the revision of the 1999 WHO guidelines for iodine thyroid blocking (ITB) by following the WHO handbook for guideline development. This article describes the process and methods of developing the revised, evidence-based WHO guidelines for ITB following nuclear and radiological accidents, the results of the kick-off meeting as well as further steps taken to complete the revision.

Managing Internal Radiation Contamination Following an Emergency: Identification of Gaps and Priorities.

Following a radiological or nuclear emergency, first responders and the public may become internally contaminated with radioactive materials, as demonstrated during the Goiânia, Chernobyl and Fukushima accidents. Timely monitoring of the affected populations for potential internal contamination, assessment of radiation dose and the provision of necessary medical treatment are required to minimize the health risks from the contamination. This paper summarizes the guidelines and tools that have been developed, and identifies the gaps and priorities for future projects.

Survey of the WHO-REMPAN network's capability for strengthening preparedness for radiological and nuclear emergencies.

This paper investigates the capacity of the World Health Organization (WHO)-REMPAN network in responding to radiological incidents and nuclear emergencies. A survey developed by the WHO Secretariat and Nagasaki University was sent to all 40 WHO-REMPAN collaborating centres and liaison institutes in order to verify the current situation of the network, identify needs and collect suggestions for future improvements. Most of the responding institutions said they were satisfied with the current status of the network. However, several responses to the survey indicate that better internal communication is needed, as well as a position document to specify the roles, rights and responsibilities of the network members.

WHO's public health agenda in response to the Fukushima Daiichi nuclear accident.

The World Health Organization (WHO) has responded to the 2011 East-Japan earthquake and tsunami through the three levels of its decentralised structure. It has provided public health advice regarding a number of issues relating to protective measures, potassium iodide use, as well as safety of food and drinking water, mental health, travel, tourism, and trade. WHO is currently developing an initial health risk assessment linked to a preliminary evaluation of radiation exposure around the world from the Fukushima Daiichi nuclear accident. Lessons learned from this disaster are likely to help future emergency response to multi-faceted disasters.

First global consensus for evidence-based management of the hematopoietic syndrome resulting from exposure to ionizing radiation.

OBJECTIVE: Hematopoietic syndrome (HS) is a clinical diagnosis assigned to people who present with ≥ 1 new-onset cytopenias in the setting of acute radiation exposure. The World Health Organization convened a panel of experts to evaluate the evidence and develop recommendations for medical countermeasures for the management of HS in a hypothetical scenario involving the hospitalization of 100 to 200 individuals exposed to radiation. The objective of this consultancy was to develop recommendations for treatment of the HS based upon the quality of evidence. METHODS: English-language articles were identified in MEDLINE and PubMed. Reference lists of retrieved articles were distributed to panel members before the meeting and updated during the meeting. Published case series and case reports of individuals with HS, published randomized controlled trials of relevant interventions used to treat nonirradiated individuals, reports of studies in irradiated animals, and prior recommendations of subject matter experts were selected. Studies were extracted using the Grading of Recommendations Assessment Development and Evaluation (GRADE) system. In cases in which data were limited or incomplete, a narrative review of the observations was made. No randomized controlled trials of medical countermeasures have been completed for individuals with radiation-associated HS. The use of GRADE analysis of countermeasures for injury to hematopoietic tissue was restricted by the lack of comparator groups in humans. Reliance on data generated in nonirradiated humans and experimental animals was necessary. RESULTS: Based upon GRADE analysis and narrative review, a strong recommendation was made for the administration of granulocyte colony-stimulating factor or granulocyte macrophage colony-stimulating factor and a weak recommendation was made for the use of erythropoiesis-stimulating agents or hematopoietic stem cell transplantation. CONCLUSIONS: Assessment of therapeutic interventions for HS in humans exposed to nontherapeutic radiation is difficult because of the limits of the evidence.

Literature review and global consensus on management of acute radiation syndrome affecting nonhematopoietic organ systems.

OBJECTIVES: The World Health Organization convened a panel of experts to rank the evidence for medical countermeasures for management of acute radiation syndrome (ARS) in a hypothetical scenario involving the hospitalization of 100 to 200 victims. The goal of this panel was to achieve consensus on optimal management of ARS affecting nonhematopoietic organ systems based upon evidence in the published literature. METHODS: English-language articles were identified in MEDLINE and PubMed. Reference lists of retrieved articles were distributed to conferees in advance of and updated during the meeting. Published case series and case reports of ARS, publications of randomized controlled trials of relevant interventions used to treat nonirradiated individuals, reports of studies in irradiated animals, and prior recommendations of subject matter experts were selected. Studies were extracted using the Grading of Recommendations Assessment Development and Evaluation system. In cases in which data were limited or incomplete, a narrative review of the observations was made. RESULTS: No randomized controlled trials of medical countermeasures have been completed for individuals with ARS. Reports of countermeasures were often incompletely described, making it necessary to rely on data generated in nonirradiated humans and in experimental animals. A strong recommendation is made for the administration of a serotonin-receptor antagonist prophylactically when the suspected exposure is >2 Gy and topical steroids, antibiotics, and antihistamines for radiation burns, ulcers, or blisters; excision and grafting of radiation ulcers or necrosis with intractable pain; provision of supportive care to individuals with neurovascular syndrome; and administration of electrolyte replacement therapy and sedatives to individuals with significant burns, hypovolemia, and/or shock. A strong recommendation is made against the use of systemic steroids in the absence of a specific indication. A weak recommendation is made for the use of fluoroquinolones, bowel decontamination, loperamide, and enteral nutrition, and for selective oropharyngeal/digestive decontamination, blood glucose maintenance, and stress ulcer prophylaxis in critically ill patients. CONCLUSIONS: High-quality studies of therapeutic interventions in humans exposed to nontherapeutic radiation are not available, and because of ethical concerns regarding the conduct of controlled studies in humans, such studies are unlikely to emerge in the near future.

A new handbook on triage, monitoring and treatment of people following malevolent use of radiation.

Through the Euratom 6 Framework Programme, the European Commission is co-sponsoring the specific targeted research project "Triage, Monitoring and Treatment-Handbook for management of the public in the event of malevolent use of radiation" (TMT Handbook). The main aim of the project is to produce a handbook for the effective and timely triage, monitoring, and treatment of people exposed to radiation following a malevolent act. The World Health Organization contributed to this project with development of guidelines on medical and public health response. A training course based on the TMT Handbook was developed. It will help to enhance national capacity for planning and response to acts involving the malevolent use of radiation. The course will also provide a platform to identify common challenges and discuss opportunities for harmonizing response strategies throughout the European Union. Focusing on its medical and public health response aspects, this paper introduces the TMT Handbook and its potential applicability not only as practical guidance for end-users but also as a useful tool for education and training.

WHO-REMPAN for global health security and strengthening preparedness and response to radiation emergencies.

In response to the changing global environment and emerging new issues related to health security, the World Health Organization (WHO) is putting in place new tools for collective defense, such as the revised International Health Regulations (IHR) (2005). The new framework puts additional responsibilities on both Member States and WHO itself in order to effectively implement the IHR (2005) and react effectively in case of public health emergency events of any nature. Since its establishment in 1987, the Radiation Emergency Medical Preparedness and Assistance Network of WHO (WHO-REMPAN) has become an important asset for the organization's capacity to respond to radiation emergencies and to assist its Member States to strengthen their own response capacities. The paper describes in detail the framework for the WHO's role in preparedness and response to radiation emergencies, including Emergency Conventions and IHR (2005), and how the WHO-REMPAN, through its activities (i.e., technical guidelines development, training, education, research, and information sharing), provides a significant contribution to the organization's program of work towards achievement of the global health security goal.

Some considerations for mass casualty management in radiation emergencies.

Radiation emergencies are rather new to humankind, as compared to other types of emergencies such as earthquakes, floods, or hurricanes. Fortunately, they are rare, but because of that, planning for response to large-scale radiation emergencies is least understood. Along with the specific technical aspects of response to radiation emergencies, there are some general guiding principles of responding to mass casualty events of any nature, as identified by the World Health Organization in its 2007 manual for mass casualty management systems. The paper brings forward such general considerations as applicable to radiation mass casualty events, including (1) clear lines of communication; (2) scalability of approach; (3) whole-of-health approach; (4) knowledge based approach; and (5) multisectoral approach. Additionally, some key considerations of planning for mass casualty management systems are discussed, namely, health systems surge capacity and networking, risk and resources mapping, and others.

Global networking for biodosimetry laboratory capacity surge in radiation emergencies.

For the public health management of radiation emergencies, one of the essential components of integrated risk assessment is to quickly and accurately assess and categorize the exposure. In addition to other methods, biodosimetry is instrumental to support decision-making for: 1) efficient secondary triage in a hospital response phase; 2) multi-parameter approach for defining best-treatment strategies for those severely exposed; 3) clinical prognosis and assessment of risk; and 4) reassurance and psychological support for those potentially exposed, or "worried-well." In large-scale events, the number of victims, and especially those worried-well, is likely to overwhelm hospital and laboratory capacities in the accident area. This is already being addressed through the networking approach within several countries and/or regions of the world. The paper reports about WHO's activity toward coordination of these regional efforts and the international collaborative network of biodosimetry laboratory services, WHO BioDoseNet. The network includes more than 30 laboratories around the world and supports the implementation of the revised International Health Regulations, the scope of which since 2007 also covers the field of radionuclear incidents.

Thyroid nodules, polymorphic variants in DNA repair and RET-related genes, and interaction with ionizing radiation exposure from nuclear tests in Kazakhstan.

Risk factors for thyroid cancer remain largely unknown except for ionizing radiation exposure during childhood and a history of benign thyroid nodules. Because thyroid nodules are more common than thyroid cancers and are associated with thyroid cancer risk, we evaluated several polymorphisms potentially relevant to thyroid tumors and assessed interaction with ionizing radiation exposure to the thyroid gland. Thyroid nodules were detected in 1998 by ultrasound screening of 2997 persons who lived near the Semipalatinsk nuclear test site in Kazakhstan when they were children (1949-1962). Cases with thyroid nodules (n = 907) were frequency matched (1:1) to those without nodules by ethnicity (Kazakh or Russian), gender and age at screening. Thyroid gland radiation doses were estimated from fallout deposition patterns, residence history and diet. We analyzed 23 polymorphisms in 13 genes and assessed interaction with ionizing radiation exposure using likelihood ratio tests (LRT). Elevated thyroid nodule risks were associated with the minor alleles of RET S836S (rs1800862, P = 0.03) and GFRA1 -193C>G (rs not assigned, P = 0.05) and decreased risk with XRCC1 R194W (rs1799782, P trend = 0.03) and TGFB1 T263I (rs1800472, P = 0.009). Similar patterns of association were observed for a small number of papillary thyroid cancers (n = 25). Ionizing radiation exposure to the thyroid gland was associated with significantly increased risk of thyroid nodules (age and gender adjusted excess odds ratio/Gy = 0.30, 95% CI 0.05-0.56), with evidence for interaction by genotype found for XRCC1 R194W (LRT P value = 0.02). Polymorphisms in RET signaling, DNA repair and proliferation genes may be related to risk of thyroid nodules, consistent with some previous reports on thyroid cancer. Borderline support for gene-radiation interaction was found for a variant in XRCC1, a key base excision repair protein. Other pathways such as genes in double-strand break repair, apoptosis and genes related to proliferation should also be pursued.