Lifetime follow-up of USTUR Case 246 demonstrated the lack of severe biological effects resulting from his exposure to 241Am. Deterministic effects observed were limited to hematological changes, including lymphopenia and thrombocytopenia. These hematological changes were consistent with those observed in experimental animals following actinide exposure. Cataracts were removed from the left and right eyes at 547 and 1,030 d after the accident, respectively, but were considered to be trauma-induced rather than radiation-induced. No abnormal findings were reported from gross or histological examinations of tissue samples removed at autopsy, other than those resulting from the subject's preexisting cardiovascular disease.