Exposure to magnetic fields among electrical workers in relation to leukemia risk in Los Angeles County

Authors

  • Dr. Stephanie J. London MD, DrPH,

    Corresponding author
    1. Department of Preventive Medicine, University of Southern California School of Medicine, Los Angeles
    • U.S.C. School of Medicine, PMB B 306, 1420 San Pabio St., Los Angeles, CA 90033
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  • Joseph D. Bowman PhD,

    1. Department of Preventive Medicine, University of Southern California School of Medicine, Los Angeles
    Current affiliation:
    1. National Institute of Occupational Safety and Health, Cincinnati, OH
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  • Eugene Sobel PhD,

    1. Department of Preventive Medicine, University of Southern California School of Medicine, Los Angeles
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  • Duncan C. Thomas PhD,

    1. Department of Preventive Medicine, University of Southern California School of Medicine, Los Angeles
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  • David H. Garabrant MD, MS,

    1. Department of Preventive Medicine, University of Southern California School of Medicine, Los Angeles
    Current affiliation:
    1. Department of Environmental and Industrial Health, University of Michigan School of Public Health, Ann Arbor
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  • Neil Pearce MBBS,

    1. Department of Medicine, Wellington School of Medicine, Wellington Hospital, Wellington, New Zealand
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  • Leslie Bernstein PhD,

    1. Department of Preventive Medicine, University of Southern California School of Medicine, Los Angeles
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  • John M. Peters MD, SCD

    1. Department of Preventive Medicine, University of Southern California School of Medicine, Los Angeles
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Abstract

To Address the hypotheses that electrical workers are exposed to higher magnetic fields and are at higher risk of leukemia than nonelectrical workers, we performed a registry-based case-control study among men aged 20–64 years with known occupation who were diagnosed with cancer in Los Angeles County between 1972 and 1990. Controls were men with cancers other than those of the central nervous system or leukemia. Magnetic field measurements on workers in each electrical occupation and in a random sample of occupations presumed to be nonelectrical were used to estimate magnetic field exposures for each occupation. Among men in electrical occupations, 121 leukemias were diagnosed. With the exception of electrical engineers, magnetic field exposures were higher among workers in electrical occupations than in nonelectrical occupations. A weakly positive trend in leukemia risk across average occupational magnetic field exposure was observed (odds ratio [OR] per 10 milligauss increase in average magnetic field = 1.2, 95% confidence interval [CI] 1.0–1.5). A slightly stronger association was observed for chronic myloid leukemia, although only 28 cases occurred among electrical workers (OR 10 milligauss increase = 1.6, 95% CI = 1.2–2.0). The results were not materially altered by adjustment for exposure to several agents known or suspected to cause leukemia. Although not conclusive, these results are consistent with findings from studies based on job title alone that electrical workers may be at slightly increased risk of leukemia.

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