Airborne moulds in human environment - health relevance and risk assessment

An overview is given on the spectra and quantities of airborne microfungi in different human environments. Characteristic species spectra can be described when the ratios of different species are taken into account. Certain species can therefore serve as indicators, but only when the air-spora in outdoor air is taken into account: A high ratio of Cladosporium herbarum in indoor air may rather point to a contamination from outdoors (C. cladosporioides and C. sphaerospermum seem more abundant on building materials), while high ratios of A. versicolor and R chrysogenum are indicative of microbial contamination of building material due to moisture. in case of fresh biowaste as emission source high ratios of P glabrum and P roqueforti are likely, while apart from thermotolerant Aspergillus-species P. crustosum and P polonicum are characteristic for older biowaste or compost. Health implications of airborne microfungi are discussed with special regard to the uncertainties in risk assessment with respect to infection, allergy, and intoxication. On the basis of the results from recent studies the options and limitations of risk assessment are summarized, and the need and perspectives for future research are shortly pointed out.