The beginning, middle, and end: development of a job exposure matrix for three chemicals over four decades for one epidemiologic study.
Source
American Industrial Hygiene Conference and Exposition, May 9-15, 1998, Atlanta, Georgia. Fairfax, VA: American Industrial Hygiene Association, 1998 May; :40
Abstract
The process to develop a job exposure matrix (]EM) includes the identification, acquisition, assembly, manipulation, interpretation, and application of data. Original industrial hygiene data collected over 40 years (at a gaseous diffusion plant) were used to estimate airborne concentrations of uranium, nickel, and fluorides. This process began with the identification of about 16,000 industrial hygiene surveys and initially covered over 100 buildings. Sampling methods ranged from Greenberg-Smith impingers to current day filter cassettes. Unification of contaminant identities and units was necessary to facilitate subsequent exposure characterization. A total of 5220 industrial hygiene sample results were used in the final JEM. Problems encountered during data processing included censored data, missing limits of detection, unknown sample volumes and durations, and unsampled time intervals. Buildings ultimately included in the JEM were those with 50 or more samples. Industrial hygiene data were pooled by decade based on historical knowledge of site activities and to compensate for unsampled periods. The skewness of the historic industrial hygiene data prompted the development of exceedance values for the uranium and fluoride data assigned to a decade. Exceedance values represented the proportion of airborne contaminant values that exceeded an occupational exposure limit during a decade. Reference exposure limits used were the threshold limit values existing at the start of plant operations. The process enabled an assignment of exposure based on the proportion of time contaminant levels may have exceeded an advisory level, utilizing contaminant data collected during the time period of interest. The effort required to produce the JEM was more involved than the final product suggests.
Keywords
Epidemiology; Job-analysis; Employee-exposure; Occupational-exposure; Industrial-hygiene; Information-systems; Exposure-assessment; Exposure-levels; Exposure-limits; Air-contamination; Uranium-compounds; Nickel-compounds; Fluoride-compounds; Fluorides; Air-samples; Air-sampling; Sampling; Sampling-methods; Impingers; Filters
CAS No.
7440-61-1; 7440-02-0; 16984-48-8
Source Name
American Industrial Hygiene Conference and Exposition, May 9-15, 1998, Atlanta, Georgia
