A study of beryllium exposure measurements, part 1: estimation and categorization of average exposures from daily weighted average data in the beryllium industry.
Seiler-DH; Rice-C; Herrick-RF; Hertzberg-VS
Appl Occup Environ Hyg 1996 Feb; 11(2):89-97
A strategy for developing job specific exposure estimates from time weighted average exposures was described and illustrated by applying it to daily weighted average (DWA) beryllium (7440417) exposure data contained in the files of the Industry Wide Studies Branch of NIOSH. The DWA data had been collected by NIOSH and other agencies at five beryllium processing facilities from 1950 through 1978 and were to be used in developing exposure measurements for a NIOSH cohort mortality study of beryllium refinery workers. The data set consisted of 2,249 exposure measurements representing 491 different job titles at the five facilities. The data were first tested to determine if they were lognormally distributed, after which attempts were made to calculate the mean beryllium exposures for each job title. The DWA exposure data were confirmed to be lognormally distributed. Most of the facility/specific job title exposures contained less than 30 data points and 207 of the 491 job titles were represented by only one datum. Small sample size statistics were used to calculate the arithmetic mean (AM) exposures for each job title. A total of 284 facility/specific job titles contained at least two data points over time, and the points were plotted versus time using various group categories to test for possible time trends in the data. Few trends in the job title/specific exposure estimates over time were seen. Of the data plots, 239 were considered to be grouped, that is, all the data points in the plot came within +/-1 log unit of each other. The grouped category accounted for 82% of the job title exposure estimates. Analysis of the plots indicated that AM exposures for a given job title differed substantially between the facilities. For a given year, the data were too sparse to enable estimates of facility/specific job title exposures to be made. The authors note that additional exposure data exist in company records and other archival sources. Utilizing these data would probably improve the exposure estimates, especially for job titles with few data points.
NIOSH-Publication; NIOSH-Author; NIOSH-Grant; Grants-other; Training; Alkaline-earth-metals; Occupational-exposure; Workplace-monitoring; Metal-industry-workers; Job-analysis; Industrial-hygiene
Environmental Health University of Cincinnati 3223 Eden Avenue Cincinnati, OH 45267-0056
Other Occupational Concerns; Grants-other
Applied Occupational and Environmental Hygiene
University of Cincinnati, Cincinnati, Ohio