A study is in progress to estimate the contamination of the human food chain by uranium, /sup 230/Th, /sup 226/Ra /sup 210/Pb, and /sup 210/Po originating from tailing piles associated with uranium ore processing mills.^Rabbits, cattle, vegetables, and grass were collected on or near two uranium mill sites.^For controls, similar samples were obtained from areas 20 km or more from the mining and mill operations.^For the onsite rabbits the mean /sup 226/Ra concentrations in muscle, lung, and kidney of 5.5, 14, and 15 pCi/kg wet, respectively, were substantially higher than those in the respective tissues of control animals (0.4, 1.5, and 0.2 pCi/kg).^The levels in liver did not differ significantly between the groups.^The concentrations in bone (femur and vertebra) were about 9000 and 350 pCi/kg ash for the onsite and offsite animals, respectively.^The levels of /sup 210/Pb and /sup 210/Po did not differ significantly for a given tissue between the two groups, except that the /sup 210/Pb level in the kidney was greater in the onsite group.^For cattle, the concentrations in muscle, liver, and kidney do not differ greatly between those grazed near the pile and the controls.^The levels of /sup 226/Ra, and possibly of /sup 210/Pb, appear to be greater in the femur of the animals near the piles.^Vegetables from a residential area on a mill site contained substantially greater concentrations of /sup 226/Ra and /sup 210/Pb than those reported for standard New York City diets.^Grass and cattle dung from land irrigated by water containing 60 pCi/L /sup 226/Ra from uranium mines had concentrations of /sup 226/Ra and /sup 210/Pb 50 and 8 times, respectively, those in control samples.^It is estimated that doubling the normal concentrations in meat and vegetables of uranium and daughter products could increase the dose equivalent rates to the skeletons of persons consuming these foods by 30 or more mrem/yr.
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