NATIONAL ACADEMY OF SCIENCES STUDY OF STRATEGIES FOR KI DISTRIBUTION AND ADMINISTRATION
Some time has passed since the report of the NAS committee was published (Distribution and Administration of Potassium Iodide in the Event of a Nuclear Accident, Board of Radiation Effects Research, National Research Council, The National Academies Press, 2004), and it is time to assess whether its conclusions and recommendations have had an effect on the availability of KI to the American public. The report reviewed background information on the benefits and risks of KI administration, and on the populations likely to benefit from KI. It then presented an extensive catalogue of existing distribution plans in the 17 states using pre-distribution and in 4 with post-distribution only. Information about programs in 14 countries was also given. In Appendix D a detailed process was described by which communities could design and evaluate potential KI distribution plans. Finally, three sets of conclusions and recommendations were presented, each related to what the committee considered to be the main issues it was charged to evaluate. They are succinctly presented in the Executive Summary of the report. For this critique they are abbreviated, paraphrased and commented upon here.
Benefits and Risks Posed by KI Distribution
The report concluded that KI is an important agent for protection against thyroid-related effects of exposure to radioiodine if taken shortly before or after exposure, but that the Chernobyl accident is not necessarily a good model in planning for incidents in the United States because of differences in reactor design. It recommended that KI should be available to everyone at risk, including infants, children, pregnant women and adults younger than 40 years, and should be taken within a few hours of exposure to inhaled or ingested radioiodine. KI distribution should consider pre-distribution, local stockpiling outside the 10-mile emergency planning zone (EPZ) of nuclear power plants, national stockpiles and distribution capacity.
The report did not define the radius outside the EPZ that KI programs should address. A radius of 20 miles is required by the Bioterrorism Act of 2002 (P.L.107-188) but this is much too restricted in light of the Chernobyl experience. The winds after that accident carried the radioactive plume 150 miles to Bryansk, Russia, where thyroid cancer induced by 131-I was found (Davis S et al, Radiation Res 162:241-248, 2004) and 300 miles to eastern Poland where it was shown that a single dose of KI given 3 days after the accident, combined with restriction of milk intake, reduced the thyroid radiation dose by 70%, and that 40% of this reduction was from protection against inhaled 131-I (Nauman J and Wolff J, Am J Med 94: 524-532, 1993). Although an accident like Chernobyl may be less likely in the USA, the extent of spread of the plume containing 131-I could be similar.
Implementation Issues Related to KI Distribution and Stockpile Programs
The report concluded that a strategy is needed for local agencies to develop boundaries for KI distribution, and that conditions and states vary so much that no single best solution is possible. It recommended that state and local authorities should design and implement distribution plans based on their objectives, on features of their local regions and on risk estimates. It also recommended that the federal government should supplement the states’ programs by maintaining stockpiles and a distribution system that would ensure an adequate supply of KI tablets appropriate for the target populations. It recommended further that a better understanding of strengths, weaknesses, successes and failures, and resource requirements of existing KI distribution plans in the USA would be helpful for future programs.
The text of the report can assist states and localities without KI programs to design theirs by reviewing what others have done, and by following the suggestions given in Appendix D. No suggestions concerning how the recommended follow-up evaluations would be carried out were given. It is necessary to review what federal government agencies have done to provide and maintain the supply of KI needed for the states’ and localities’ programs. The draft of a guidance document from the Radiological Emergency Preparedness Section, Department of Homeland Security and the Department of Health and Human Services has been circulated for comment. The ATA found this draft to be inadequate in scope because it provides only for procurement of KI tablets by states and localities and gives no assistance with distribution or stockpiling.
- HHS KI Guidance Response Letter (December 15, 2004).
- Health and Human Services Guidelines Mislead and Misinform About Important Role of Potassium Iodide in Nuclear Incident, Say Thyroid Experts (Dec. 21, 2004)
Additional Research Needed
The report concluded that there is now sufficient knowledge to estimate thyroid cancer risks from radioiodine. Its recommendations for future research were keyed only to KI distribution plans. It recommended that the plans should include carefully developed and tested public education programs that are subject to continuing evaluation, that a national program for follow-up of persons given KI should be developed, and that the resource requirements of different KI plans should be evaluated by a federal agency. Other areas for research were also discussed in the text.
There is overlap between this section and the previous one emphasizing the need for continuing development and reevaluation of KI distribution plans. The committee, however, did not make recommendations for designing a mechanism that would actively assist the states and localities in creating and evaluating their individual programs. This would presumably require involving a federal or other agency with expertise to deal with the complex social and logistic requirements of such programs. The public’s interest in having the best possible protection against injury from a nuclear incident is fragmented by differing interpretations of need and methods to be employed. Since not all regions have, or will have, KI programs, the committee should have also given advice for individual members of the public concerning how they can provide for their own protection by informing them about KI tablets available for purchase.
The ATA Public Health Committee is awaiting release of a revised guidance document from DHS and DHHS, after which it will consider ways that might improve a still deficient program for protecting the public from thyroid injury resulting from a nuclear incident.