A study of smoke exposure at prescribed fires was done by the USDA Forest Service, Pacific Northwest Research Station and Radian Corporation between 1991 and 1994. This study was done to assess exposure to smoke among firefighters at prescribed fires in the Pacific Northwest. The study compared the relative smoke exposure potential of each job task at a prescribed fire and identified environmental conditions associated with high smoke exposures. The study examined the correlations among pollutants in smoke to determine whether exposure to many pollutants might be estimated from measurements of a single surrogate pollutant. The study also evaluated simple dosimeter technology for routine monitoring of carbon monoxide exposure.