EXPOSURE TO MAGNETIC-FIELDS AMONG ELECTRICAL WORKERS IN RELATION TO LEUKEMIA RISK IN LOS-ANGELES-COUNTY

To address the hypotheses that electrical workers are exposed to highe r magnetic fields and are at higher risk of leukemia than nonelectrica l workers, we performed a registry-based case-control study among men aged 20064 years with known occupation who were diagnosed with cancer in Los Angeles County between 1972 and 1990. Controls were men with ca ncers other than those of the central nervous system or leukemia. Magn etic field measurements on workers in each electrical occupation and i n a random sample of occupations presumed to be nonelectrical were use d to estimate magnetic field exposures for each occupation. Among men in electrical occupations, 121 leukemias were diagnosed. With the exce ption of electrical engineers, magnetic field exposures were higher am ong workers in electrical occupations than in nonelectrical occupation s. A weakly positive trend in leukemia risk across average occupationa l magnetic field exposure was observed (odds ratio [OR] per 10 milliga uss increase in average magnetic field = 1.2, 95% confidence interval [CI] 1.0-1.5). A slightly stronger association was observed for chroni c myloid leukemia. although only 28 cases occurred among electrical wo rkers (OR 10 milligauss increase = 1.6, 95% CI = 1.2-2.0). The results were not materially altered by adjustment for exposure to several age nts known or suspected to cause leukemia. Although not conclusive, the se results are consistent with findings from studies based on job titl e alone that electrical workers may be at slightly increased risk of l eukemia. (C) 1994 Wiley-Liss, Inc.