To generate quantitative exposure estimates for use in retrospective occupational cohort mortality studies of the hardmetal industry.
Job-exposure matrices (JEMs) were constructed for cobalt, tungsten, and nickel over the time period 1952 to 2014. The JEMs consisted of job class categories, based on job titles and processes performed, and exposure estimates calculated from available company industrial hygiene measurements.
Exposure intervals of one-half order magnitude were established for all three agents. Eight job classes had significantly decreasing time trends for cobalt exposure; no significant time trends were detected for tungsten or nickel exposures.
The levels of exposures determined for this study were similar to or lower than those previously reported for the hardmetal industry during the 1952 to 2014 study period.
Division of Environmental and Occupational Health Sciences, School of Public Health, University of Illinois at Chicago, Chicago, Illinois (Drs Kennedy, Esmen); Center for Occupational Biostatistics and Epidemiology, Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania (Dr Buchanich, Ms Zimmerman, Dr Marsh); Institute of Occupational Medicine, Edinburgh, UK (Dr Sleeuwenhoek).
Address correspondence to: Kathleen J. Kennedy, PhD, Environmental and Occupational Health Sciences, School of Public Health, University of Illinois at Chicago, Chicago, IL 60612 (firstname.lastname@example.org).
Funding Sources: This project was sponsored by grants from the Pennsylvania Department of Health and by a research subcontract between the University of Illinois at Chicago and the University of Pittsburgh, through funding by the International Tungsten Industry Association. Study design, conduct, analysis, and conclusions are those of the authors.
The research proposal was approved by the Institutional Review Boards of the University of Illinois at Chicago and the University of Pittsburgh.
Conflict of Interest: The authors declare no conflict of interest.