Electromagnetic fields and breast cancer on Long Island: a case-control study.

The EMF and Breast Cancer on Long Island Study (EBCLIS) was a case-control study designed to evaluate the possible association between exposure to electromagnetic fields (EMFs) and breast cancer. Eligible women were participants in the population-based Long Island Breast Cancer Study Project, were under 75 years of age at enrollment, were residentially stable, and were identified between August 1, 1996, and June 20, 1997. Of those eligible, 576 cases and 585 controls participated in EBCLIS (87% and 83%, respectively). In-home data collection included various spot and 24-hour EMF measurements, ground-current magnetic field measurements, wire mapping of overhead power lines servicing the home, and an interview. Odds ratios and 95% confidence intervals were based on multivariate logistic regression analyses. All odds ratios were close to 1 and nonsignificant. For the highest quartile of 24-hour EMF measurements, the odds ratio was 0.97 (95% confidence interval (CI): 0.69, 1.37) in the bedroom and 1.09 (95% CI: 0.78, 1.51) in the most lived-in room. For the highest exposure category of ground-current measurements, the odds ratio was 1.13 (95% CI: 0.88, 1.44) in the bedroom and 1.08 (95% CI: 0.85, 1.38) in the most lived-in room. These and other EBCLIS results agree with other recent reports of no association between breast cancer and residential EMF exposures.