Smoke exposure at western wildfires

Smoke exposure measurements among firefighters at wildfires in the Western United States between 1992 and 1995 showed that although most exposures wer e not significant, between 3 and 5 percent of the shift-average exposures e xceeded occupational exposure limits for carbon monoxide and respiratory ir ritants. Exposure to benzene and total suspended particulate was not signif icant, although the data for the latter were limited in scope. The highest short-term exposures to smoke occurred during initial attack of small wildf ires, but the shift-average exposures were less during initial attack than those at extended (project) fire assignments because of unexposed time duri ng the shift. Among workers involved in direct attack of actively burning a reas and maintaining fireline boundaries, peak exposure situations could be several times greater than recommended occupational exposure limits for sh ort-term exposures. The study found that exposure to acrolein, benzene, for maldehyde, and respirable particulate matter could be predicted from measur ements of carbon monoxide. Electrochemical dosimeters for carbon monoxide w ere the best tool for routinely assessing smoke exposure, so long as qualit y assurance provisions were included in the monitoring program. Suggested p rocedures for reducing overexposure to smoke include (1) hazard awareness t raining, (2) routinely monitoring smoke exposure, (3) evaluating health ris ks and applicable exposure criteria, (4) improving health surveillance and injury recordkeeping, (5) limiting use of respiratory protection when other mitigation is not feasible, and (6) involving workers, managers, and regul ators to develop a smoke exposure management strategy.