Florida beefwas sampled during May, 1966, and the first halfof 1967 and analyzed for 137Cs to help define the unusual radioecological situation first suggested by radionuclide levels observed in Florida milk. Cesium-I37 levels in grain-fed beef showed a geographic trend with the highest levels, 110-540 pCi/kg, occurring in the southern and south-central parts of the State and the lowest levels, 55-175 pCi/kg, occurring in the northwestern part. Levels in beef showed the same general geographic pattern shown by levels in milk.These findings and the results reported for Florida milk and dairy feeds indicate that this nuclide is concentrated to higher levels in biological materials in much of Florida than would be predicted from the distribution and levels of fallout deposition and from the average concentration by these media in other parts of the country.

Measurement of 137Cs body burdens in nearly 300 persons with the University of Florida whole-body counter from 1965 to date shows that Florida residents had levels of 137Cs two to three times as high as those reported elsewhere in the conterminous United States during the same time period. Analysis of the data by year shows that the levels did not drop with time as rapidly as levels reported in other areas of the United States.Cesium-137 levelsin Florida residents averaged 0.395,0.353, and0.318 nCi/kglean body mass in 1965, 1966 and 1967, respectively. For the entire 1965-1967 period these levels averaged 0.350 and had a range of 0.044-1.667nCi/kg lean body mass. In contrast, non-Florida residents measured at the same facility had an average of 0.151 nCi/kg lean body mass. Reproducibility of the measurements was within 10%.These levels correlate with the reported levels of 137Cs in Florida-produced foods, which in general are much higher than the average for the United States.