Mycotoxin air sampling in indoor environments - Comparison of risk assessment using Trichothecene screening test and conventional fungal identification methods

Typically fungal risk assessment is based on fungal identification and quantification, but appears often poorly correlated with specific epidemiological health outcomes. In this study, we compared conventional fungal identification methods with a new tests for mycotoxin screening (effect-based of mycotoxins screening test using a MTT-cell culture assay) and quantification of trichothecenes by a Roridin A/trichothecene ELISA test. High volume air sampling (24h) (n=206) was conducted in patient homes or offices (n=96) with environmental symptomatology and visible fungal indoor growth. Approximately two third of the air samples showed mild to high (+ to +++) toxicity in the MTT cytotoxicity test and 19 % of (n=176) of the air filter samples had RoA results of >10 ng/g. Among all the fungi identified, there was only a weak association of viable Stachybotrys fungi and RoA (by Spearman rank order, p=0.009), but not with other fungi. In conclusion, traditional fungal identification methods appear to be a poor predictor of (trichothecene) toxicity results.