Kidney and bone retention functions in the human metabolism of uranium

Abstract

The retention of uranium by bone and kidney has been re-evaluated taking account of recently published data for a man who had been occupationally exposed to natural uranium aerosols and for adults who had ingested uranium at the normal dietary levels. For lifetime occupational exposure to uranium aerosols the new retention functions yield a greater retention in bone and a smaller retention in kidney than the earlier ones, which are based on acute intakes of uranium by terminal patients. Hence bone replaces kidney as the critical organ. The occupational (MPC)a for 238U and U-nat based on radiological considerations and the new retention functions are slightly lower than for the earlier ones. For 238U the (MPC)a determined by chemical toxicity remains the more restrictive.