Power Lines No Cancer Threat
Study Finds Zero Risk from Electromagnetic Fields in Homes
June 27, 2003 -- Overhead power lines don't increase breast-cancer risk, a New York study finds.
The data comes from an extremely thorough study of nearly 600 cancer patients and 600 matched volunteers. Everyone in the study was a long-time resident of either Nassau or Suffolk county on New York's Long Island.
The two counties have unusually high rates of breast cancer. Why? The National Cancer Institute and the National Institute of Environmental Health Sciences tried to find out by funding a series of studies.
The largest of the studies looked at environmental pollution. It's main finding, released last year, showed that residents of the two counties suffered a 50% increase in breast cancer risk from PAH, an ingredient in air pollution. As cancer risks go, that's considered only a "modest" increase in risk. Cigarette smoking ups lung-cancer risk by 900%.
Next, Stony Brook University researcher Elinor Schoenfeld, PhD, and colleagues looked at whether strong electric fields might be the breast-cancer culprit. They report their findings in the July 1 issue of the American Journal of Epidemiology.
"We found no association between electromagnetic field levels ... and breast-cancer risk," Schoenfeld and colleagues conclude. "This study thus provides no empirical evidence suggesting that residential electromagnetic field exposures contribute to the risk of breast cancer on Long Island."
It's not likely they missed anything, the researchers say. They didn't just map overhead power lines. They also took electromagnetic field readings from various spots in all the residents' houses, including 24-hour measures. They took readings from electric lines in the ground and also interviewed each resident.
Did they miss anything? The scientists point to the study's large sample size, its extensive quality control procedures, it's extensive accounting for other factors that might cause cancer. "The lack of association found is unlikely to have been the result of errors," they note.
An earlier study of electric fields and cancer in Seattle, Wash., reached similar conclusions. A third study of the issue is ongoing in California.