Mould Exposure & Mycotoxin Testing Explained
Mould is common in Australian homes and workplaces, especially in humid climates or water-damaged buildings — and for some people, ongoing exposure is linked to a real but easily overlooked pattern of symptoms. If you've been searching "mould poisoning" or "mould toxicity test," here's what's actually behind those terms.
What does mould exposure look like?
Symptoms linked to mould exposure vary between people and can include fatigue, brain fog, respiratory irritation, sinus congestion, headaches and skin irritation. Long-term exposure to dampness or mould at home or work increases the risk of developing respiratory symptoms, asthma, and rhinitis, with combined home and workplace exposure showing particularly strong associations. None of these symptoms are specific to mould on their own — which is exactly why exposure history (have you lived or worked somewhere with visible mould or water damage?) matters as much as symptoms when deciding whether testing is worth it.
Is "mould illness" medically accepted?
This is worth addressing directly, because it's a genuinely contested area. Allergic and respiratory effects of indoor fungi are well-established. However, the broader idea of chronic "mould illness" or CIRS (Chronic Inflammatory Response Syndrome) as a defined medical diagnosis is still debated within mainstream medicine, and isn't universally recognised as a standalone condition.
The American College of Medical Toxicology (2025) notes that while allergic effects of indoor fungi are well-documented, the role of inhaled mycotoxins in causing toxic health effects in indoor residential environments remains doubtful due to study limitations. Exposure modeling studies have concluded that even in mouldy environments, the maximum inhalation dose of mycotoxins is generally orders of magnitude lower than demonstrated thresholds for adverse health effects.
Building sickness syndrome is recognized in the medical literature, but no diagnostic test is available - diagnosis relies on a careful history of symptoms and environmental exposures, and exclusion of other causes. Some research has identified structural brain abnormalities in patients with CIRS from water-damaged buildings, though these studies lack the rigorous validation that mainstream medicine requires for diagnostic criteria.
Testing gives you information - a marker of exposure - not a diagnosis. That's why interpretation of results with a practitioner experienced in environmental medicine, alongside your symptoms and history, is essential.
What does a mycotoxin test actually measure?
A mycotoxin test measures mycotoxin metabolites in urine using validated LC-MS/MS methods. However, it's important to understand that mycotoxins detected in urine primarily reflect dietary exposure (from contaminated foods like grains, nuts, and coffee) rather than inhalation from indoor mould.
The most commonly measured urinary mycotoxins include aflatoxin M1, ochratoxin A, deoxynivalenol, zearalenone metabolites, and fumonisin B1 — all of which are predominantly dietary in origin. The short elimination half-life of most mycotoxins means urine testing cannot reliably confirm remote or chronic inhalation exposure from water-damaged buildings. According to the American College of Medical Toxicology, "It is inappropriate to attribute identification of mycotoxins in urine to postulated remote inhalation exposure".
Urine mycotoxin testing is most relevant if you have a known or suspected history of exposure - for example, having lived or worked in a water-damaged building - combined with unexplained symptoms. It doesn't tell you where the mould is or diagnose an illness; it gives you one data point about exposure to work through with a practitioner.
What happens during testing?
Testing is done from home with no GP referral required: you order online, collect a urine sample using the kit provided, and view your results in your dashboard once processed. From there, we'd recommend booking time with a practitioner experienced in environmental or integrative medicine to interpret the result properly in the context of your history and symptoms.
Does a clear result rule out mould as a factor?
Not necessarily. A single mycotoxin test is a snapshot, and results can be affected by timing, hydration and individual metabolism. Additionally, because urine mycotoxin levels primarily reflect recent dietary exposure rather than inhalation from indoor mould, a positive result doesn't necessarily confirm building-related exposure, and interpretation requires careful consideration of all exposure sources. If you have a strong exposure history and ongoing symptoms despite a clear result, that's a conversation for your practitioner rather than something the test alone can settle.
What if I've already been diagnosed or suspect exposure?
If you're past the "is this mould?" stage and focused on recovery, our guide on mould toxicity and nutritional support covers how diet and lifestyle can support your body's detox pathways during recovery.
Next steps
If your symptoms and exposure history line up, testing can be a useful starting point. View the full range of mould and environmental toxin tests, including the Mycotoxin Mould Exposure Test, heavy metal testing, and hair mineral analysis.
The information in this article is for educational purposes only and is not a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of your physician or another qualified healthcare provider with any questions about a medical condition. If you suspect mould exposure or are experiencing related symptoms, consult a healthcare professional for personalised guidance.
