Health hazard evaluation report: HETA-89-136-1991, Blue Range Mining Company, Lewistown, Montana.
Cincinnati, OH: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control, National Institute for Occupational Safety and Health, HETA 89-136-1991, 1989 Oct; :1-20
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;
Field Studies; Hazard Evaluation and Technical Assistance
NTIS Accession No.
National Institute for Occupational Safety and Health