Ate ee le Ci de tallest ld JiataieW Eathensath aes RADIUM-226 IN THE DIET OF TWO U. S. CITIES I. M. Fisenne and H. W. Keller A revised estimate of the daily radium-226 dietary intake in three cities (New York City, Chicago and San Francisco) was reported in April 1969. °)) At that timé, a comparison of the 1960 and 1966 diet estimates showed that the 1966 values were from 27% to 50% lower than the 1960 values. This difference was due to the change in the analytical procedure for radium-226. To obtain a more representative estimate of dietary intake, a second food sampling from the New York City and San Francisco was analyzed for radium-226. No Ghicago diet samples were available for analyses, since food sampling from this city was terminated in 1968. Samples of New York City and San Francisco area tap water were also analyzed for radium-226, The HASL food sampling program is described in HASL-200. ¢”? The tap water samples from New York City represent an integrated one month collection. The San Francisco area tap water sample was collected on a single day. The radium-226 diet level estimates are shown in Tables 1 and 2. Duplicate sample analyses are also listed. The yearly consumption , figures are taken from a U. S. Department of Agriculture report. (3) The average daily intake of radium-226 in the two cities may be com- puted from these data. San Francisco 1.7 pCi/day 0.8 pCi/day tw New York City were ae wo me . oe Se os re ore Sn — cp ree a peer ee FE aTLe ae eae