1976 Hanford americium exposure incident: organ burden and radiation dose estimates.

A Hanford worker received an intake of 241Am by skin absorption and inhalation which was later evaluated to be in excess of 1 mCi. The skin was the main pathway for introduction of 241Am into the body; however inhalation was also a significant pathway. Intensive DTPA therapy prevented 99% of 241Am which entered the blood stream from being deposited in the internal organs. Retention and distribution of 241Am in various internal organs and tissues was determined from sequential measurements in vivo using several arrangements of externally located scintillation detectors. The organ and tissue retention and distribution have been followed for longer than 5 yr. Excretion patterns and estimates of radiation dose to the lung, liver, bone and skin are described.