Brain tumor risk in children in relation to use of electric blankets and water bed heaters. Results from the United States West Coast Childhood Brain Tumor Study.

The possible relation between the occurrence of brain tumors in children and exposure to electric blankets or electrically heated water beds was investigated in a multicenter, population-based case-control study conducted on the West Coast of the United States. Information on maternal exposure during pregnancy or direct exposure to the subject child was collected by in-person interview from the mothers of 540 case children and 801 control children. Cases were 19 years of age or younger and were diagnosed between 1984 and 1991. Controls were recruited using a random digit dialing procedure. The risk of brain tumor occurrence from in utero exposure to either electric blankets (odds ratio (OR) = 0.9, 95% confidence interval (Cl) 0.6-1.2) or heated water beds (OR = 0.9, 95% Cl 0.6-1.3) was not elevated. Brain cancer risk did not vary by use in any trimester of pregnancy, and children with mothers who reported use throughout their pregnancy had no increased risk. Similar results were observed for exposure to the child, in that no association between brain cancer and use of electric blankets (OR = 1.0, 95% Cl 0.6-1.7) or heated water beds (OR = 1.2, 95% Cl 0.7-2.0) was observed. Risks did not vary significantly by age, sex, race, socioeconomic status, or histologic category for either in utero exposure or child's exposure. This study provides no evidence to support the hypothesis that there is a relation between brain cancer occurrence in children and 50-/60-Hz magnetic field exposure from the use of electric blankets and heated water beds.