93 Microbial Contaminants and Pro-Inflammatory Properties of Organic Dust From Different Occupational Settings

Abstract

Abstract The study aimed to characterize the microbial contamination of dust samples from various occupational environments and to assess their impact on the release of pro-inflammatory cytokines from cell culture. The research was conducted in six occupational settings, including waste sorting and composting plants, a sewage treatment plant, a cement plant using alternative fuel, a power plant co-firing biomass as well as a poultry farm. In total, 76 organic dust samples were collected at 26 workplaces in the above-mentioned plants to assess the concentrations of: inhalable dust fraction, crystalline silica, aerobic and anaerobic bacteria, fungi as well as peptidoglycans, endotoxins and (1→3)-β-D-glucans. The alveolar epithelial cells (A549) were exposed to dust extracts and the levels of pro-inflammatory cytokines (IL-6 and IL-8) were determined. The highest inhalable dust concentrations were found in the power plant samples – 5.60 mg/m3 (SD=9.13). In poultry houses, the highest concentrations were noted for aerobic and anaerobic bacteria – 201129 cfu/m3 (SD=62795) and 72702 cfu/m3 (SD=13532), respectively. In turn, the waste sorting plant workplaces were the most contaminated with fungi – 36335 cfu/m3 (SD=27270), endotoxins – 23.9 ng/m3 (SD=21.5) and SiO2 – 0.024 mg/m3 (SD=0.026). The highest levels of peptidoglycans – 7930 ng/m3 (SD=6049) and (1→3)-β-D-glucans – 180.5 ng/m3 (SD=46.4) were found at workplaces in composting plant. The release of cytokines was significantly dependent (p<0.05) on dust concentrations for composting and cement plants; however, to a lesser extent, their production were also stimulated by aerobic bacteria, fungi, endotoxins and crystalline silica. The microbial characteristics of organic dusts may trigger the pro-inflammatory reactions in workers.