Household Magnetic Fields and Childhood Leukemia: A Critical Analysis

Abstract

For the past two decades, considerable interest and concern have been expressed, particularly in the lay media, over the hazards of exposure to the electric and magnetic fields from high-voltage transmission lines, electric appliances in the home, and video display terminals. Laboratory research and observations on human populations indicate that electric fields from these sources do not constitute a health hazard to humans or animals. There are reports, however, of an apparent association between magnetic fields and cancer or leukemia in selected populations. The quality of these reports and the validity of the conclusions, however, are questionable. Nevertheless, these studies have generated considerable public anxiety. This is exemplified by an article published in the New Yorker magazine (July 1990). The author relates in graphic detail accounts of a suspected cancer cluster on a single street in a community in Connecticut. Resources for this investigative report were largely second-hand accounts from newspapers and personal interviews with small nuclei of residents that suggested a relationship with exposure to electric and magnetic fields from a nearby electric substation. This article fanned the fires of public concern about electric and magnetic field-induced health dangers despite the fact that state and local health officials emphasized there was no evidence to confirm a connection. Almost weekly discussions in newspapers and magazines and on television, as well as the publicity given to a forthcoming Environmental Protection Agency report, have exacerbated the concern. ENVIRONMENTAL FACTORS Humans are exposed to a wide variety of natural and artificial electromagnetic fields. The predominant natural magnetic field is the earth's static magnetic field, which has a strength of about 0.5 G. Electric power is transmitted as direct current and/or as alternating current (AC) at 50 or 60 Hz.