Radiation Doses and Cause-Specific Mortality Among Workers at a Nuclear Materials Fabrication Plant

Abstract

A historical cohort mortality study was conducted among 6,781 white male employees from a nuclear weapons materials fabrication plant for the years 1947-1979. Exposures of greatest concern are alpha and gamma radiation emanating primarily from insoluble uranium compounds. Among monitored workers, the mean cumulative alpha radiation dose to the lung was 8.21 rem, and the mean cumulative external whole body penetrating dose from gamma radiation was 0.96 rem. Relative to US white males, the cohort experienced mortality deficits from all causes combined, cardiovascular diseases, and from most site-specific cancers. Mortality excesses of lung and brain and central nervous system cancers were seen from comparisons with national and state rates. Dose-response trends were detected for lung cancer mortality with respect to cumulative alpha and gamma radiation, with the most pronounced trend occurring for gamma radiation among workers who received greater than or equal to 5 rem of alpha radiation. These trends diminished in magnitude when a 10-year latency assumption was applied. Under a zero-year latency assumption, the rate ratio for lung cancer mortality associated with joint exposure of greater than or equal to 5 versus less than 1 rem of both types of radiation is 4.60 (95% confidence limits (CL) 0.91, 23.35), while the corresponding result, assuming a 10-year latency, is 3.05 (95% CL 0.37, 24.83). While these rate ratios, which are based on three and one death, respectively, lack statistical precision, the observed dose-response trends indicate potential carcinogenic effects to the lung of relatively low-dose radiation. There are no dose-response trends for mortality from brain and central nervous system cancers.

Exposure assessment for a cohort of workers at a former uranium processing facility

“…Mean cumulative external dose at FMPC (13.4 mGy) was slightly larger than that estimated for the Y-12 uranium facility by Watkins et al 22 (mean 8.7 mGy) and Checkoway et al 23 (mean 9.6 mGy). Dupree-Ellis et al 24 estimated a mean cumulative external dose of 48 mGy for the Mallinckrodt uranium processing facility.…”

Cancer mortality in relation to monitoring for radionuclide exposure in three UK nuclear industry workforces

“…whe strength of prior evidence for an excess of lung cancer in nuclear industry workers monitored for exposure to radionuclides is not strong for workers in the UK or USA (Wilkinson et al 1987: Beral et al, 1988Checkoway et al, 1988;Gilbert et al, 1989;Wmg et al 1991;Fraser et al, 1993). However, workers exposed to plutonium in the radiochemical plant at Mayak, Russia, have a large excess risk of lung cancer (Koshurnikova et al 1997).…”

Depleted and Natural Uranium: Chemistry and Toxicological Effects

“…However, several epidemiological studies have found no increased mortality in uranium workers due to renal disease (Checkoway et al, 1988;Polednak & Frome, 1981). It has also been noted that renal injury resulting from uranium exposure can be diagnosed within days of exposure (ATSDR, 1999).…”

“…In studies focusing on the effects associated with inhaled uranium in miners, no adverse health effects were noted in workers who were exposed to up to 9000-10,000 µg natural uranium/m 3 . Additionally, no increase in overall deaths has been reported due to uranium exposure in mills and metal processing plants (Checkoway et al, 1988). Cooper et al (1982) investigated the respiratory effects of acute exposure (less than 15 d) to various insoluble uranium compounds, and found severe nasal congestion and hemorrhaging in 100% of the exposed rats.…”