Estimated dose to man from uranium milling via the beef/milk food-chain pathway.

One of the major pathways of radiological exposure to man from uranium milling operations is through the beef/milk food chain. Studies by various investigators have shown the extent of uptake and distribution of 238U, 234U, 230Th, 226Ra, 210Pb, and 210Po in plants and cattle. These long-lived natural radioisotopes, all nuclides of the uranium decay series, are found in concentrated amounts in uranium mill tailings. In this paper, data from these investigations are used to estimate the dose to man from consumption of beef and milk from cattle that have fed on forage contaminated with the tailings. The estimated doses from this technologically enhanced source are compared with those resulting from average dietary intake of these radionuclides from natural sources.