Exposures to Extremely Low Frequency (ELF) Electromagnetic Fields in Occupations with Elevated Leukemia Rates

Abstract

In previous epidemiological studies, elevated leukemia rates have been found in a collection of occupational categories of “electrical workers.” In this study, spot measurements were taken of the Extremely Low Frequency (below 100 Hz) electric and magnetic field exposures of “electrical workers” at 114 work sites at an electric utility, an aerospace firm, a municipal government, motion picture theaters, and TV repair shops. For comparison, the fields were measured in 18 residences and 3 offices. The residential measurements had 95th percentiles at 3.4 × 10^-7 Tesla for magnetic fields and 33.1 volts/meter for electric fields. For magnetic fields, the 95th percentile of the residential measurements was exceeded by 59 percent of the occupational measurements, covering all the “electrical worker” job categories with the exception of radio operators. The highest magnetic field encountered was 1250 × 10^-7 Tesla on a battery-powered fork lift operator, which had not been considered an “electrical worker” occupation previously. Only 25 percent of the occupational electric fields were above the 95th percentile measured in residences, and these were all in the job categories for power line workers, power station operators, and TV repairers. This survey indicates that many “electrical workers” have some exposures to elevated fields. However, the wide variability in field exposures over time and between workers will necessitate better exposure measurements to assess more rigorously the association between leukemia rates and electromagnetic fields. Bowman, J.D.; Garabrant, D.H.; Sobel, E.; Peters, J.M.: Exposures to Extremely Low Frequency (ELF) Electromagnetic Fields in Occupations with Elevated Leukemia Rates. Appl. Ind. Hyg. 3:189–194; 1988.