Workers at computer factories appear to be at greater risk for dying of several kinds of cancers. In the largest study of its kind, looked at the deaths of more than 30,000 IBM workers. They had been employed at IBM factories in the United States for more than five years.

The researcher found increased rates of death from a number of cancers. "In males, the biggest excess was actually in melanoma of the skin, but also kidney cancer, brain cancer, and also Non-Hodgkins Lymphoma," he reports. "The melanoma excess was about two times higher than would have been expected and kidney and brain cancer was 1.6 times higher or about 60 percent elevated. And Non-Hodgkins Lymphoma about 30 percent elevated."

Clapp also found higher death rates for all these cancers in women employees, as well as an increase in breast cancer. Researchers theorize that long-term exposure to solvents and other chemicals used in the manufacturing process is responsible.

Clapp says this study is significant because of its size. "There have been other small studies published in the UK and Taiwan of workers at one factory and IBM itself published a study a year ago, looking at 3 factories. But this one looked at deaths in the entire company. So it had more deaths to look at and had more robust findings."

The study was done as part of a lawsuit filed against IBM by several former workers. Clapp compared the records kept by the company with death rates in communities surrounding the factories where the workers were employed. But as the computer industry goes global, he says his results have implications beyond US borders. "These are the kinds of techniques and technologies that are being outsourced or shipped overseas. And so there are people now being exposed to the same chemicals in mainland China that used to be the exposures that people in California got, but they've been exported so to speak."

Clapp says these results are consistent with other cancer studies that have found increased cancer rates for workers exposed to solvents.