Can Microbial Volatile Metabolites Cause Irritation at Indoor Air Concentrations?

University of Kuopio, Department of Environmental Sciences, Kuopio, Finland; Corresponding author: Prof. Anna-Liisa Pasanen; University of Kuopio, Department of Environmental Sciences, email:

Sensory irritation potency of selected volatile organic compounds assumed to be of microbial origin (MVOCs) was estimated theoretically by using the data of the recent chamber experiments and the results of volatile organic compounds (VOCs) measurements in water-damaged buildings. According to the estimations, a possible risk for complaints of irritation caused by exposure to the mixtures of those MVOCs in moisture problem buildings was evaluated. Exposure to mixtures of the selected non-reactive VOCs at the theoretical airborne concentrations calculated from the data of the chamber experiments would not result in sensory irritation in humans, and, thus, microbial growth in constructions should not increase the probability of irritating symptoms considerably. The data on MVOC concentrations measured in some problem buildings also supported this hyphothesis. Irritation would be expected when the airborne concentrations of single assumed MVOC approach a level of hundreds of m g/m3 or mg/m3.