Exposure to dust, resin acids, and monoterpenes in softwood lumber mills

A study to assess exposure to potential respiratory hazards in a large lumb er mill processing spruce (Picea engelmannii and glauca), pine (Pinus conto rta), and fir (Abies lasiocarpa) used a random sampling strategy to assess exposures for all jobs in the sawmill, planer mills, and yard. Personal sam ples for inhalable particulate were collected to measure exposure to dust a nd resin acids (abietic acid and pimaric acid). To estimate wood dust expos ure, rather than overall dust, the resin acid content within dust was used in combination with observations of job tasks and proximity to dust sources . Passive dosimeters were used to measure exposure to alpha-pinene, beta-pi nene, Delta(3)-carene, and other unidentified wood volatiles suspected to b e monoterpenes. The GM of the 220 inhalable particulate samples was 1.0 mg/ m(3) whereas the mean abietic acid, pimaric acid, and estimated wood dust l evels were 7.2 mu g/m(3), 0.6 mu g/m(3), and 0.5 mg/m(3), respectively. The GMs of the 222 monoterpene samples were 0.1 mg/m(3) for alpha-pinene, 0.3 mg/m(3) for beta-pinene, 0.1 mg/m(3) for Delta(3)-carene, and 0.5 mg/m(3) f or the unidentified wood volatiles. Monoterpene exposures were much lower t han those observed in other studies conducted in Sweden and Finland. The re sults of this exposure assessment highlight the importance of considering t he content of airborne particulates in lumber mills as well as potential ex posure to wood chemicals.