The aim of this study was to establish the concentrations of mixed populations of fungi in in door air and to attempt to correlate these concentrations and health complaints of residents. We investigated 68 rooms. These were divided into four groups: rooms without moulds on the walls and with/or without complaints; rooms without moulds on the walls and with/or without complaints. Health problems were noted by those living in the rooms and these were non-specific symptoms such as cough, headache, rhinitis and sore throat. The total concentrations of airborne fungi (monitored by aeroscop) were much higher in mouldy rooms than in the reference rooms. Even if health complaints did not correlate with the total concentrations of airborne fungi, all occupants of rooms where the average concentrations was 2 476 cfu/m 3 reported health complaints. Concentration of fungi in indoor air above 2 000 cfu/m 3 can be considered to be a serious risk factor for health of occupants.

        Key words: fungi, health complaints, indoor air, mouldy rooms, relative humidity, temperature