HETA Report No. TA-80-000-105, Forest Service, USDA, Spokane, Washington.
NIOSH 1982 Mar:23 pages
In response to a request from the U.S. Forestry Service (SIC-0851), an investigation was conducted by NIOSH to evaluate the exposure of Forest Service personnel to volcanic ash after the May 18, 1980 eruption of Mount St. Helens. Forest workers in southwestern Washington State were monitored in June and September, 1980 for exposure to airborne dust, total dust, and trace metals. Respirable crystalline silica (14808607) dust exposure was estimated by sieving bulk samples to particles less than 10 micrometers in diameter. Nine of 40 measurements obtained from forestry workers exposed to respirable dust were greater than 1.00mg/m3 during the first survey. The NIOSH recommended exposure level to respirable dust containing 5.5% crystalline silica was 0.91mg/m3. No respirable dust measurements obtained in late summer were above the NIOSH recommended exposure level. The author concludes that forestry workers exposed to dust concentrations below the recommended levels have little risk in developing chronic respiratory impairment from this exposure; however, the recommended exposure levels may have certain limitations and future volcanic activity may increase risk. The author recommends that working conditions should be reassessed in future volcanic eruptions.
NIOSH-Author; NIOSH-Technical-Assistance-Report; Region-10; TA-80-000-105; Hazard-Confirmed; Dust-inhalation; Forestry-workers; Occupational-exposure; Respirable-dust; Mineral-dusts; Silica-dusts; Volcanic-ash;
Hazard Evaluation and Technical Assistance; Field Studies
NTIS Accession No.
Mining Health Hazard Evaluation and Technical Assistance Program, NIOSH, U.S. Department of Health and Human Services, Morgantown, West Virginia, Report No. TA-80-000-105, 23 pages, 8 references