Assessment of magnetic field exposures for a mortality study at a uranium enrichment plant.
Am Ind Hyg Assoc J 1999 Nov/Dec; 60(6):818-824
A survey of workplace exposures to 60-Hz magnetic fields was carried out at a large uranium enrichment facility to assign exposures for an updated mortality study. Stratified random selection was used to choose workers for measurement in all jobs and areas, to determine whether consistent distinctions could be made between job groups based on average magnetic field exposures. A total of 252 workdays was measured with a personal monitor, and individual average magnetic field exposures ranged from 0.20 to 82.6 mG. A priori job groups showed significant differences between geometric mean exposures, which ranged from 0.80 to 3.51 mG. Most of these groups showed widely ranging exposures, so they were subdivided based on location and job title to improve the precision of the exposure assignments for the mortality study. These final assignments were made up of 26 groups having arithmetic means ranging from 0.43 to 24.9 mG, with most groups defined by location in addition to job title. In general, electrical maintenance workers did not have elevated magnetic field exposures (> 3 mG), but the exposures of the electricians in switchyard (substation) jobs were elevated. Available employment records did not allow most electricians to be distinguished based on location, so they were assigned exposures based on their plantwide average (above 7 mG). An estimated 9% of the work time of this cohort was spent at daily average exposures above 3 mG, despite the very large electric power consumption at this plant.
Magnetic-fields; Magnetic-properties; Mortality-rates; Mortality-data; Uranium-compounds; Uranium-miners; Uranium-mining; Occupational-exposure; Worker-health; Work-environment; Workplace-monitoring; Epidemiology; Exposure-assessment;
Author Keywords: bimodality; exposure assessment for epidemiology; magnetic field exposures; uranium workers
National Institute for Occupational Safety and Health, Mail Stop R-44, 4676 Columbia Parkway, Cincinnati, OH 45226
American Industrial Hygiene Association Journal