Authors reply

The authors reply to a letter by Johnson, C.J. which was critical of their report of mortality of plutonium workers at the Rocky Flats Plant. The letter clarifies the method by which the cohort was defined in their study, defends their use of urine bioassays for the assessment of plutonium body burden, and suggests that the report makes a significant contribution to the literature on the potential plutonium has to induce human disease. They state that the results of their studies suggest that increased risk for several cancers cannot be ruled out for persons with plutonium body burdens of 2 nanocuries or more. Their previous recommendation that studies of workers should be continued in future years was reemphasized