Environmental Risk Factors
Does exposure to electromagnetic fields increase the risk of breast cancer?
No. Nearly a decade ago, three studies reported that men who worked as electricians, telephone linemen, or power company employees had breast cancer more frequently than men in other occupations. The risk estimates were based on a very small number of men: only two cases in the first study. One theory proposed that electromagnetic fields might increase the risk of cancer. Several dozen new studies looked at groups of workers and found that exposure to electromagnetic fields was not associated with breast cancer or other cancers. The researchers did not find higher rates of breast cancer among men who worked near power lines: the earlier findings had turned up merely by chance.
A population-based study in Denmark measured the incidence of cancer over a 17-year period for people with occupational exposures to intermittent or to continuous electromagnetic fields. Among the 79,000 and 4,000 women in these occupational categories, the rates for breast cancer were the same as the rates for the 1.5 million women who had no occupational exposure to electromagnetic fields. Population studies in Finland and the Netherlands found no difference in the risk of breast cancer according to residence near power lines or electrical facilities. The most common household source of exposure to electromagnetic fields is the electric blanket. However, three studies of the risk of breast cancer among women found that those who had never used electric blankets, heated mattress pads, or heated waterbeds developed breast cancer as often as women who used those items frequently.
Because of public concern about exposure to power lines or other magnetic fields, the National Academy of Sciences reviewed all of the scientific articles—hundreds of them—and issued a consensus statement in 1997 that electromagnetic fields were not a health hazard.
