Researchers found that while death rates from many causes were lower than national rates, workers had higher-than-expected rates of death from certain cancers.

Among men, leukemia and cancer of the pleura, the tissue covering the lungs and lining the chest cavity, caused an abnormally high number of deaths, while female workers had elevated rates of kidney and skin cancers.

Pleural cancer is strongly related to long-term exposure to asbestos. Some workers at the Savannah River Site were apparently overexposed to asbestos, based on "industrial hygiene" reports from the early 1970s, according to the researchers.

Dr. David B. Richardson and colleagues at the University of North Carolina at Chapel Hill report the findings in the American Journal of Industrial Medicine.

The study included 18,883 employees of the Savannah River Site who were hired prior to 1987 and worked there for at least three months.

When the researchers looked at deaths from all causes and deaths from all cancers as a whole, the workers had rates that were below the US norm. However, as mentioned, there was an excess of certain cancers.

"It is plausible," Richardson and his colleagues write, "that occupational hazards, including asbestos and ionizing radiation, contribute to these excesses."

The findings highlight the importance of ongoing government research into former nuclear workers' health, according to the researchers. This, they write, will be key to understanding "the range of potential occupational health effects," especially diseases that typically take years to become apparent.