HHE Report No. HETA-89-136-1991, Blue Range Mining Company, Lewistown, Montana.
NIOSH 1989 Oct:20 pages
In response to a request from the Blue Range Mining Company (SIC- 1041), Lewistown, Montana, an investigation was made of possible employee exposures to lead (7439921) in the fire assay process used to separate noble metals from their ores using dry reagents and heat. An 8 hour time weighted average (TWA) lead concentration of 850 micrograms/cubic meter of air (microg/m3) was noted in the personal breathing zone sample for the assayist, which was above the Mine Safety and Health Administration (MSHA) standard of 150microg/m3 at an 8 hour TWA. The employees in the assay laboratory reported an increased frequency and intensity of symptoms consistent with lead poisoning compared with nonassay laboratory employees. One of the four laboratory employees had a blood lead level of 50 micrograms/deciliter, which was above the OSHA action level of 30microg/m3. The mean free erythrocyte protoporphyrin levels were significantly higher among the assay laboratory employees compared to other employees. The authors conclude that a hazard did exist during the fire assay operations. Recommendations to management on measures to reduce this exposure are provided.
NIOSH-Author; NIOSH-Health-Hazard-Evaluation; NIOSH-Technical-Assistance-Report; Region-8; HETA-89-136-1991; Hazard-Confirmed; Lead-poisoning; Blood-analysis; Mineral-processing;
Hazard Evaluation and Technical Assistance;
NTIS Accession No.
Hazard Evaluations and Technical Assistance Branch, NIOSH, U.S. Department of Health and Human Services, Cincinnati, Ohio, Report No. HETA-89-136-1991, 20 pages, 20 references