Airborne Microbes and Endotoxins in the Work Environment of Two Sanitary Landfills in Finland

Abstract The Andersen sampler was used to study the occurrence of bacteria and fungi in the working air of two large, intensively used landfills in Finland. Endotoxins were also determined. The concentrations of airborne microbes were high in summer in warm windy weather. Mesophilic bacteria exceeded 105 colony-forming units (cfu)/m3 and mesophilic fungi 104 cfu/m3. In 67% of the samples, the concentrations of gram-negative bacteria exceeded 103/m3, which has been suggested to be the threshold limit value (TLV). The endotoxin levels were all below 0.1 μg/m3. A large part of the colony-forming particles were within the respirable size range, about 40% of the bacteria and about 80% of the fungi. The commonly isolated airborne bacteria were Pseudomonas, Enterobacter, and Bacillus spp. The landfill workers should try to work upwind. There are also grounds for using a mask and irrigating the refuse terrace with leachate in dry weather. It is suggested that the traffic on the refuse terrace be decreased by arranging for the private cars to be emptied in the reception area.