12 The more distant nature of fallout deposition was noticed fn 1945, but not In this case, emphasis was on exposed published until later (Webb, 1949). photographic film rather than exposed human populations. That fallout was present at distances far from the site of detonation was again demonstrated in the early 1950s in enviromental samples (precipitation) that contained high levels of unnatural radioactivity (Mefnke, 1951; Holter and Glasscock, 1952; Clark, 1954). Fallout occurring outside of the test sites, however, was not considered to create any immediate or long-range health hazard (AEC, 1953a). A network of monitoring stations for fallout radioactivity was established in 1951 (Eisenbud, 1957). Fallout 90Sr levels, fran data fran those stations, were published by Eisenbud and Harley (1953). The presence of fallout 1311 jn thyrofd glands was first published by Van Middlesworth (1954). The potential for health erfects from these radionuclides, however, was not a cause for significant discussion in these early papers. Although there was local worry about exposures from the Nevada test site in the early 1950s, serious concern about the health effects of radioactive fallout arose with the detonation of a larger weapon in 1954 (Anonymous, 1954). A detonation on March 1, 1954 in the Central Pacific resulted in fallout that necessitated the evacuation of 28 Americans and 236 native inhabitants fran the Marshal} Islands. Twenty-three fisherman on a Japanese trawler were also exposed to the fallout, and suffered significant medical effects. One of the fishermen died on Septenber 23, 1954 (Arnold, 1954), fran Viver damage (Appendix VI, Conard et al., 1980). The Marshallese manifested early effects as well, and showed a number of late effects, many of then related to exposures of the thyroid gland, One person also died from acute ! 1 myelogenous leukemia (Conard et al., 1975, LANG).