In 1986, officials of the US Department of Energy revealed that the Hanford Atomic Products Operations in Richland, Washington, had been releasing radioactive material, in particular iodine-131, into the environment over a period of years. This information, which confirmed the suspicions of some people in the Pacific Northwest about what they called the Hanford Reservation or just Hanford, created quite a stir. Both the US Congress and citizens of the Northwest became keenly interested in knowing whether these radiation releases had caused human health effects. They were particularly concerned about whether Hanford releases of iodine-131 had led to an increase in thyroid disease among the population of the area. In 1988, Congress ordered a study of the human health effects of exposure to the iodine-131 released from Hanford. Funded by the Centers for Disease Control and Prevention (CDC), the study was carried out by the Seattle-based Fred Hutchinson Cancer Research Center over the last decade. The study examined estimate of exposure of the thyroid and rates of thyroid disease because iodine-131 concentrates in the thyroid and that organ would be the best indicator of radiation damage in the population. The Centers for Disease Control and Prevention (CDC) asked the National Academy of Sciences-National Research Council (NAS-NRC) to give an independent appraisal of the study methodology, results, and interpretation and of the communication of the study results to the public. Review of the Hanford Thyroid Disease Study Draft Final Report constitutes the response of the NRC subcommittee to that request. To respond to the charge, the NRC subcommittee felt that it needed to go beyond the specific questions addressed to it by CDC and develop a broad understanding and critique of the HTDS and the Draft Final Report. As part of those activities, the subcommittee solicited comments from outside experts and members of the public primarily in a public meeting h