Assess the incidence of leukemia and thyroid in the state of Utah in relation to fallout from the Nevada Test Site between 1950 and 1962. Between June, 1982, and June, 1987, carry out five related studies: an assessment of fallout pattern in Utah, a reconstruction of the milk production, processing, and distribution system in the state during the 1951-1962 time interval, and a milk consumption survey among individuals in the thyroid studies; a case-control study ofthyroid cancer; a cohort study of thyroid disease; a case-control study of leukemia; and a cohort study of leukemia.