Electric blanket or mattress cover use and breast cancer incidence in women 50-79 years of age

Previous research has demonstrated inconsistent associations between electr omagnetic radiation, especially from electric blanket use, and breast cance r. Breast cancer risk according to electric blanket or mattress cover use w as examined as part of a multicenter population-based case-control study. B reast cancer patients 50-79 years of age (N = 1949) were identified from st atewide tumor registries in Massachusetts, New Hampshire, and Wisconsin fro m the period June 1994 to July 1995. Women of similar age were randomly sel ected from population lists as controls. Information regarding electric bla nket and mattress cover use and breast cancer risk factors was obtained thr ough telephone interviews. After adjustment for age, body mass index, and o ther breast cancer risk factors, the risk of breast cancer was similar amon g ever-users (relative risk = 0.93; 95% confidence interval = 0.82-1.06) an d lower among current users than among never-users (relative risk = 0.79; 9 5% confidence interval = 0.66-0.95). There was no evidence of a dose respon se relation with increasing number of months that electric blankets had bee n used. This study provides evidence against a positive association between electric blanket or mattress cover use and breast cancer.