preparedness programs. To be effective, such a program would need to be national in scope and in the form of a registry to follow affected people for many years.

Recommendation 3: Research is needed in a number of areas to provide better information to inform policy-makers and health-care providers about the risks posed by radioiodine exposure and methods to minimize long-term health effects. An evaluation of the strengths and weaknesses, successes and failures (short-term and long-term), and resource requirements of the different KI distribution plans implemented in the US and abroad should be conducted by a federal agency to aid states and local regions in designing and implementing effective KI distribution programs.

Research is needed to develop more effective KI distribution programs that address the critical issues of KI availability to appropriate at-risk populations, predistribution approaches to improve long-term public awareness of the location of KI tablets, and effective risk-communication strategies to maximize information transfer and minimize public anxiety. Research is also required to improve understanding the effect of dietary iodine in modifying the carcinogenic risk posed by radioiodine; of the type, frequency, and clinical course of thyroid tumors that develop in those exposed to radioiodine as children; of the risk of thyroid carcinogenesis in adults exposed to radioiodine in fallout; of the risk and mechanisms of autoimmune disease and hypothyroidism after radioiodine exposure; and of the risk of tumor development at other sites after radioiodine exposure.