ASSESSMENT OF BIOAEROSOL CONTAMINATION IN AN URBAN WASTEWATER TREATMENT PLANT IN TEHRAN, IRAN

Introduction: Recently contact with bioaerosols has been presented as an important problem which endangers human being's health. In this study bioaerosol concentration was measured in wastewater treatment (WWTP) units in west of Tehran. Materials and methods: Passive sampling was carried out around three process and operational units, in 100 m from last unit of wastewater treatment plant and in administrative building. In total 440 samples were collected. The transport culture medium used for bacterial samples was the tryptic soy agar, and for fungal samples, it was dextrose agar. Sampling was carried out according to the sampling calendar of Environmental Protection Agency (EPA) in 2013 for 1 h every 6 days and in the plates of 9 cm. Results:The results showed that aerobic digester with an average of 3303 CFU/Plate had the greatest effect on emission of bacterial bioaerosols. In addition grit chamber with an average of 586.3 CFU/Plate had a highest impact on fungal emission. Among the bacteria, Bacillus spp. Staphylococcus spp. and Micrococcus spp. were dominant. The highest emission of bacterial aerosol is in July and the lowest is in March. Furthermore, fungi such as Cladosporium spp. Penicillium spp. and Alternaria spp. were the dominant types in the wastewater treatment plant. The highest emission of fungal aerosols is in March and the lowest emission is in July. Conclusions: According to the results, operational and processing units of WWTP influence pollution load and dispersion of bioaerosols. Therefore, appropriate environmental health management in WWTP could be one of the important factors reducing dispersion of bioaerosols.