In Chapter 5, the focus is communicating with the public about the information and conclusions presented in both the NCI and the IOM/NRC report. The key conceptual and technical issues examined include the characteristics of risk communication, the matter of credibility of sources of information, the effectiveness of different strategies of risk communication, the need to involve the affected parties in the communication process, and the need to assess the effectiveness of different ways of formulating risk and communicating it to the various interested publics. An example of a method to assist individuals in estimating their personal thyroid cancer risk is provided in Addendum 5. As historical context relevant to understanding government actions and policies during the period of atmospheric weapons testing, a summary of dose limits for exposures of the thyroid for members of the public during this period is included in Appendix E.
Chapter 6 briefly considers directions for future research that might refine the risk estimates and reduce their inherent uncertainties.
An important determinant of the public's reaction to the information about iodine-131 exposure and risks associated with that exposure is that the aboveground nuclear tests were purposive, man-made phenomena that left behind a toxic residue. Since the tests ended, governments and residents of areas adjacent to the test sites have engaged in intermittent, often acrimonious debate about the possible health effects. The historical and political contexts surrounding the Nevada testing program and its aftermath combined with the technical nature of the analyses of iodine-131 exposure, health risks, and screening strategies will make it difficult to communicate information in ways that will be perceived as equally credible and understandable by all those concerned about the consequences of the testing program. The rest of this report offers guidance to the Department of Health and Human Services, but it is only one step in the process of developing credible and helpful communication with the public.