Mycotoxins in the ventilation systems of four schools in Finland

Some fungal species have been listed as a problem causing fungi in indoor air and most of this group are known to produce mycotoxins. So far, mycotoxins have been found in building materials and in samples representing settled indoor air dust, as well in air samples from industrial or agricultural environments. The present paper presents the results of a mycological study and mycotoxin analyses of dust collected from mechanical ventilation systems in four school buildings in southern Finland. The aim of this work was to answer the question 'Are there mycotoxins in ventilation systems and if so, from where do they originate?' A total of 40 mycotoxins representing indoor and outdoor sources alike were screened in this study, while cultivable fungi were screened using four different cultivation media. Mycotoxins were present in all ventilation systems studied, both in the supply and the exhaust systems examined. The mycotoxins found included satratoxins, verrucarol, trichodermol, enniatins, beauvericin, peni...