Exposure to inhalable dust, wheat flour and alpha-amylase allergens in industrial and traditional bakeries

This study was designed to characterize exposure to inhalable dust, wheat flour and alpha-amylase allergens in industrial and traditional bakeries. The study included 70 bakeries from the northern part of Belgium. Based on the degree of automation and a clear division of individual job tasks, four bakeries were identified as industrial and the remaining 66 were identified as traditional ones. Personal, as well as stationary, samples of inhalable dust were collected during full shift periods, usually 5-7 h. The portable pumps aspirated 2 l/min through Teflon personal dust samplers (Millipore, pore size 1.0 microm) mounted in PAS-6 sampling heads. In the collected samples the inhalable dust, wheat flour and alpha-amylase allergens were determined. Wheat flour allergens were measured using enzyme-linked immunosorbent assay inhibition and an antiwheat IgG4 serum pool. The alpha-amylase allergens were measured using a sandwich enzyme immunoassay with affinity-purified polyclonal rabbit IgG antibodies. In total, 440 samples (300 personal and 140 stationary) were processed. The highest inhalable dust exposure was observed in traditional bakeries among bread [geometric mean (GM) 2.10 mg/m3] and bread and pastry workers (GM 1.80 mg/m3). In industrial bakeries the highest dust exposure was measured in bread-producing workers (GM 1.06 mg/m3). Similar relations were observed for wheat flour and alpha-amylase allergens. Bread baking workers in traditional bakeries had the highest exposure to both allergens (wheat flour GM 22.33 microg/m(3), alpha-amylase GM 0.61 ng/m3). The exposure to wheat flour and alpha-amylase allergens in industrial bakeries was higher in bread baking workers (wheat flour GM 6.15 microg/m3, alpha-amylase GM 0.47 ng/m3) than in bread packing workers (wheat flour GM 2.79 microg/m3, alpha-amylase GM 0.15 ng/m3). The data presented suggest that, on average, exposure in the Belgium bakeries studied-industrial as well as traditional-is lower than or similar to bakeries in The Netherlands, Canada, Sweden, the United Kingdom and Finland. Furthermore, the exposure levels in traditional bakeries seem to be higher than in industrial bakeries.