LAUSR

Purpose The concentration and distribution characteristics of airborne bacteria and fungi were assessed at municipal solid-waste processing and disposal facilities (SWPDFs) of Tehran (Arad Kouh Site). Methods Air samples were obtained from the indoor air of a laboratory and refectory as well as from the air surrounding a conveyor belt, rotary screen, and bailer. Sampling was conducted according to the standard procedure to determine two bacterial species ( Klebsiella spp. and Staphylococcus aureus ), total bacteria and fungi, and Aspergillus fumigates . Results The maximum concentration of Staphylococcus aureus was in the air surrounding the conveyer belt with the average of 993.2 CFU/m 3 . The highest concentrations of total fungi (4958.8 CFU/m 3 ) and Aspergillus fumigates (2114 CFU/m 3 ) were measured in the air surrounding the rotary screen. The mean concentrations of bacterial bioaerosols in a more contaminated sampling location in summer and winter were 1687.6 and 1479.4 CFU/m 3 , respectively. Conclusions There were significant differences between the concentration of bioaerosols in cold and warm seasons. The concentrations of bioaerosols in the air surrounding the rotary screen and conveyer belt were significantly more than those in other sampling locations, but were within the recommended maximum of 10 3 and 10 4 CFU/m 3 .