Determinants of exposure to inhalable particulate, wood dust, resin acids,and monoterpenes in a lumber mill environment

In a lumber mill in the northern inland region of British Columbia, Canada, me measured inhalable particulate, resin acid, and monoterpene exposures, and estimated wood dust exposures. Potential determinants of exposure were documented concurrently, including weather conditions, tree species, wood c onditions, jobs, tasks, equipment used, and certain control measures. Over 220 personal samples were taken for each contaminant. Geometric mean concen trations were 0.98 mg/m(3) for inhalable particulate, 0.49 mg/m(3) for esti mated wood dust, 8.04 pg/m(3) for total resin acids, and 1.11 mg/m(3) for t otal monoterpenes. Multiple regression models for all contaminants indicate d that spruce and pine produced higher exposures than alpine fir or mixed t ree species, cleaning up sawdust increased exposures, and personnel enclosu re was an effective means of reducing exposures. Sawing wood in the primary breakdown areas of the mill was the main contributor to monoterpene exposu res, so exposures were highest for the barker operator, the head rig operat or, the canter operator, the board edgers, and a roving utility worker in t he sawmill, and lowest in the planer mills (after kiln drying of the lumber ) and yard. Cleaning up sawdust, planing kiln-dried lumber, and driving mob ile equipment in the yard substantially increased exposures to both inhalab le particulate and estimated wood dust. Jobs at the front end of the sawmil l where primary breakdown of the logs takes place had lower exposures. Resi n acid exposures followed a similar pattern, except that yard driving jobs did not increase exposures. (C) 1999 British Occupational Hygiene Society. Published by Elsevier Science Ltd. All rights reserved.