Mycotoxin Exposure & Testing

What are mycotoxins?

Mycotoxins are made by some species of mould, including Aspergillus, Penicillium and Fusarium. Well-studied examples include aflatoxins, ochratoxin A, deoxynivalenol (vomitoxin), fumonisins, zearalenone and patulin. Not every mould produces mycotoxins, and the presence of mould doesn't always mean mycotoxins are present.

Potential sources of exposure

• Diet: the main source for most people. Mycotoxins can occur in grains, nuts, coffee, spices, dried fruit and some other foods. In Canada, regulators set limits and monitor levels in food.
• Damp or water-damaged buildings: mould growth indoors can lead to inhaling spores and fragments, which may carry mycotoxins.
• Occupational settings: handling grain, animal feed or mouldy materials.

What the research shows

Well established: High dietary exposure to some mycotoxins causes serious illness. Aflatoxins, for example, are classified as human carcinogens linked to liver cancer. Living in damp, mouldy buildings is consistently associated with respiratory symptoms and asthma.

Uncertain and debated: Whether low-level indoor mycotoxin exposure causes chronic multisystem illness is not established. Research in this area is limited, and studies use differing methods.

Types of testing

• Urine mycotoxin tests are marketed directly to consumers and through some practitioners. They detect mycotoxins or their breakdown products.
• Environmental assessment by a qualified professional looks for moisture problems and mould growth in a building.

Limitations of testing and interpretation

• Many people have detectable mycotoxins from everyday food, so a positive result doesn't show where exposure came from.
• Urine mycotoxin tests aren't standardized for clinical diagnosis, and there are no agreed thresholds linking levels to symptoms.
• A test result can't show whether mycotoxins are causing your symptoms.