Mold and Mycotoxins

Indoor fungal contamination — most often Stachybotrys chartarum, Aspergillus and Penicillium species — develops where building dampness persists, and can release viable spores, hyphal fragments and secondary metabolites called mycotoxins (e.g. aflatoxin B1, ochratoxin A, macrocyclic trichothecenes). The 2009 WHO indoor air quality guidelines on dampness and mould conclude that occupants of damp or mouldy buildings have up to a 75% greater risk of respiratory symptoms and asthma, and that ~13% of childhood asthma in the WHO European Region is attributable to damp housing. Aflatoxin B1 is classified by IARC (Monograph 100F, 2012) as a Group 1 human carcinogen; chronic dietary exposure causes hepatocellular carcinoma, especially in HBV-positive populations. Inhalational toxicological evidence is weaker than dietary, but Stachybotrys trichothecenes are potent protein-synthesis inhibitors implicated in sick-building symptoms. Remediation focuses on eliminating moisture, not biocide treatment.