Microbiological indoor and outdoor air quality of selected places in Visakhapatnam city, India

A study on indoor and outdoor air microbiological contamination in various rooms of public places such as RTC Complex, Government School and College building (Government degree college for women) in Visakhapatnam city, India. Investigations were conducted in the period 2014-2015. Air samples were taken twice a day, in the morning and in the afternoon. In all of the tested places a multiple growth of bacteria and significant increase of mould spores were observed in afternoons. The predominant bacteria and moulds isolated from investigated air samples were: Staphylococcus sp., Micrococcus sp., Aspergillus sp., Penicillium sp., Rhizopus sp., Cladosporium sp. and Alternaria sp. Among these microbes the presence of pathogenic and strongly allergenic microorganisms was detected. The results seem to suggest that the concentrations of bioaerosols identified in the studied areas in the afternoon were higher than the values established in the morning for the indoor background – the concentrations of both bacteria and fungal aerosol were higher in the afternoon. The air in the school principal’s room and college laboratory were considered the least contaminated with microbial aerosol due to the specific features of the rooms.