After three La Niña years in a row, many Australians are now hosting a silent but stubborn house guest: Mould. It’s insiduous – inside walls, under floors and carpet, or at the back of your wardrobe, mould can be anywhere, and it thrives in damp conditions. Mould can cause serious health issues, so, it’s best to get on top it before it claims its territory on your house.
Mould spores travel through the air and cling to surfaces – anything from skin to furniture and carpet – and, if the conditions are damp enough (anything above 60 per cent indoor humidity), mould can thrive. People with asthma and allergies are more susceptible to mould allergy (which triggers hayfever-like symptoms), but it can also cause a more serious condition: Chronic Inflammatory Response Syndrome (CIRS), a progressive multi-system illness that shares similarities with chronic fatigue.
“Allergy is often a localised problem in the nasal passages and/or skin while CIRS affects almost the whole body and is often much more severe than allergy … the limbic system in the brain seems to get sensitised,” says Dr Sandeep Gupta, a specialist general practitioner at Lotus Holistic Medicine in Queensland. “Both can co-exist in the same person but the initial research suggests there are certain gene types more prone to CIRS. This still needs to be confirmed in published studies.”
According to naturopath Briana Gunn, director of Healthy For Life, anyone exposed to mould can become unwell. “It’s a toxin for everyone but different people have different tolerances for exposure before they develop symptoms.”
Briana says that anyone exposed to mould can develop skin rashes, fatigue or even mood changes, but that around 24 per cent of Australians have a genetic susceptibility that increases their risk of more serious consequences.
“Their immune system is unable to correctly identify, immobilise and remove mould from the body once it has been breathed in, eaten or touched,” she explains. “When exposed to mould, other parts of the immune system still sense that there is a foreign pathogen in the body and attempt to disable it, which triggers a cascade of inflammation.”
Mould is even thought to affect brain function. As a leading medical expert on dementia and author of Can Adventure Prevent Dementia? A Guide to Outwitting Alzheimer’s, Dr Helena Popovic says that mould toxicity can cause problems with speech, comprehension, arithmetic, planning, problem solving, balance and co-ordination and may even cause ‘inhalational Alzheimer’s’.
“All these particles can enter the brain from our blood where they induce inflammation and oxidative stress, interfere with brain-cell metabolism and trigger production of a protein called amyloid beta, which is a potent anti-fungal agent and also the hallmark of Alzheimer’s,” she explains.
“Mycotoxins also damage brain blood vessels, reducing delivery of oxygen and essential nutrients. If mould toxicity remains undiagnosed and untreated, it can lead to debilitating symptoms and significantly reduce quality of life.”
How to spot mould
When detecting mould, here is what to look out for:
- A musty smell.
- Spotted clothing or shoes.
- Ceilings or walls that are warped.
- Dark spots on gyprock walls.
- Rising damp.
- A leaking roof or downpipe.
Why is preventing mould important?
Anyone exposed to mould can develop skin rashes, fatigue, mood changes, or other health issues. If left unchecked, for some people, mould can cause a serious health called Chronic Inflammatory Response Syndrome (CIRS).
CIRS is a progressive multi-system illness that shares similarities with chronic fatigue. “The immune system is unable to correctly identify, immobilise and remove mould from the body once it has been breathed in, eaten or touched,” says naturopath Brianna Gun. “Other parts of the immune system still sense that there is a foreign pathogen in the body and attempt to disable it.”
There is no single test that can confirm CIRS. But here’s what you can do:
- Check out the Shoemaker symptom cluster test (toxicmould.org) If you have eight or more different groups of symptoms (six for children), see a professional.
- At-home test: Take the Visual Contrast Sensitivity (VCS) test (vcstest.com), a free online test to measure your ability to see contrast, which declines with CIRS (though it’s not considered a diagnostic tool).
- See a doctor: Consult a doctor about an HLA DR/DR halotype gene test, which can indicate a susceptibility, and/or for urine tests, nasal swabs and a brain PET scan, to look for changes in glucose uptake in the brain.
- Call a professional mould inspector to confirm contamination.

How to prevent mould in your house
Ideally, rather than attempting to rid your house of mould, it’s better to prevent it from occurring in the first place. Here are some prevention methods:
- Cross-ventilation: On dry days, open windows and doors on either side of a room for airflow. Keep it closed on wet days to prevent rain and humidity from entering the home.
- Dehumidifiers: Run for 2 hours a day in each room.
- Use kitchen and bathroom exhaust fans.
- Oil of cloves or vinegar: Dilute in water and spray on bathroom grout.
- Fix any leaks fast.
- Avoid drying wet clothes on a rack indoors.
- Prevent the spread: If the mould spores look hairy or powdery, they may seed more mould growth when cleaning. Spritz with a vinegar solution before wiping to prevent this. Wear gloves and a mask.