Assessment of particulates and bioaerosols in eastern Canadian sawmills

The purpose of this study was to quantify and identify the airborne contami nation in eastern Canadian sawmills. Seventeen sawmills were chosen to cove r a wide range of size, geographic distribution, and wood species processed . Within each sawmill different work sites (debarking, sawing, sorting, or planing) were studied separately. Area sampling was performed for exposure assessment. Microbial contaminants were assessed with all-glass impingers 3 0 and six-stage Andersen microbial samplers; appropriate selective media an d culture conditions for bacteria, thermophilic actinomycetes, molds, and y easts were used. Inhalable dust, endotoxins, temperature, and humidity also were measured. Penicillium species were the most predominant molds with up to 40 different Penicillium species identified. Debarking was the working site most highly contaminated by molds, bacteria, and endotoxins (p=0.0001) , At this working site mold levels reached a maximum of 1.5 x 10(6) CFU/m(3 ), whereas the median values for culturable bacteria and endotoxin were 21, 620 CFU/m(3) and 1081 endotoxin units/m(3), respectively. Planing sites wer e the most highly dust contaminated (median: 3.0 mg/m(3)) (p <0.05), Sawmil ls of eastern Canada contain airborne biological contaminants that vary bet ween working sites, and their microflora is different from that previously described in European sawmills.