Comparison of the indoor air quality in mould damaged and reference buildings in a subarctic climate.

The purpose of this study was to search for objective parameters most relevant to indicate microbial problems of buildings in cold climate. Various indoor characteristics were compared in nine buildings with known history of moisture problems and visible mould (index) and in nine matched reference buildings. The concentrations of airborne viable fungal had a clear difference between the two groups of buildings. In this study, airborne concentrations of viable bacteria, formaldehyde, total volatile organic compounds (TVOC) and the occurrence of house dust mites in these index buildings were compared with the levels of the pollutants in matched reference buildings. Fungal growth and flora on moist building materials were also studied. The concentrations of TVOC were slightly higher in the index buildings than in the reference buildings. However, the differences in the concentrations or appearance of any of the studied pollutants were not significant. These parameters do not seem to be relevant indicators of microbial growth or surrogates of microbial exposure. Thus, fungal concentration and composition of fungal genera in the air still seems to be the best indicator for moisture problems among the studied pollutants. In the moist building materials, some fungal genera, such as Ulocladium and Chaetophoma were detected that were not found in indoor air showing that building material samples give additional information on the microflora of the building.