Reappraisal of brain tumor risk among U.S. nuclear workers: a 10-year review

A review of cohort mortality studies among workers exposed to ionizing radiation in U.S. nuclear programs was published in this journal 10 years ago. The present review extends that investigation to include four new groups of workers at Fernald (Ohio), Rocketdyne/Atomics International (California), Mallinckrodt Chemical (Missouri), and Los Alamos National Laboratory (New Mexico). The total number of brain tumors has doubled to nearly 300, with 3.8 million person-years of observation among 140,000 U.S. white male workers. This increased risk of brain tumor is highly consistent, persistent, and stable. The sum total of these studies dwarfs the reported experience of any other comparison group. The observed increased brain tumor risk is statistically significant and has changed little since 1991 when it was estimated at 15%. Study results from 1999 and 2000 may suggest a modest growing risk of 25-30%.