Monitoring of fungi and bacteria in the indoor air of primary schools in Edirne city, Turkey

We monitored levels of bacteria and fungi in the indoor air at selected sites of several public primary schools in the city of Edirne, Turkey. Sampling was by the Petri plate method onto both a Rose-Bengal streptomycin agar medium and a 5% sheep-blood agar medium exposed to the air for 10-minute periods. Samples were collected monthly over a period of 6 months between August 2001 and January 2002. A total of 941 microfungi and 2066 bacterial colonies were counted on 90 Petri plates. During this 6-month period, 19 bacterial genera, 15 fungal genera and 48 species of fungi were isolated from the air in the schools. Some bacteria, such as coagulase-negative Staphylococcus, Corynebacterium and Bacillus, were predominant (42.7%, 20.4% and 6.9% of the total, respectively). Penicillium, Cladosporium and Alternaria were the most common fungal genera (42.8%, 19.3% and 10.1% of the total, respectively). Staphylococcus, Acinetobacter, Corynebacterium, Propionibacterium and Pseudo-monas genera were found in every month. Statistical analysis of the data showed a positive correlation between the concentrations of bacteria and air humidity (p = 0.002, R-2 = 0.726) and between bacterial concentrations and age of the schools (p=0.045, R-2 = 0.787). Also, that there was seasonal variation since the concentrations of fungi and bacteria varied according to the months (p = 0.001).