Many studies have suggested that elevated occupational exposures to electromagnetic fields (EMFs) from power lines, appliances, or large electric motors might spike a woman’s risk of developing breast cancer (SN: 1/10/98, p. 29: http://www.sciencenews.org/pages/sn_arc98/1_10_98/bob1.htm). A Swedish study now appears to quash that notion. It found that the 20,400 Stockholm-area women who developed breast cancer over a 23-year period had no higher EMF exposures than did 116,000 cancerfree women from that region.
“We were surprised,” says study leader Ulla M. Forssén of the Karolinska Institute in Stockholm, whose team had found such an EMF-cancer link in an earlier study.
For the new study, Forssén’s team first collected exposure data from 470 women in 49 occupations. Each volunteer wore a device that recorded EMF exposure every 4 seconds for 24 hours. The researchers then applied those workplace-exposure data to the 136,000 women in and around Stockholm and looked for breast cancer patterns.
“We looked at these data backwards and forwards, but we just didn’t find a [cancer] link” to EMFs, says Forssén, now at the University of North Carolina at Chapel Hill. Her team reports its finding in the Feb. 1 American Journal of Epidemiology. Forssén notes that when the scientists applied the new workplace-exposure numbers to women in their previous study, the EMF-cancer link disappeared.