Understanding the hidden dangers of mould

Recognising the impact of mould on health is crucial for taking proactive measures to prevent and mitigate its harmful effects. It has been linked to a broad spectrum of health concerns from respiratory problems and allergies to cognitive impairment and weakened immune function.

By understanding the implications of mould exposure on your health and adopting safe preventive measures, you can create a healthier, mould-free living environment to ensure the wellbeing of you and your loved ones.

What’s the difference between mould, mould spores and mycotoxins?

Mould is a natural part of our environment and ecosystem, speeding up the decomposition of dead leaves and trees. Some mould species are actually beneficial to humans and are used to make antibiotics and ferment foods. Other types, however, commonly found in water-damaged buildings and homes, produce dangerous biotoxins called mycotoxins, which are harmful to our health, particularly in susceptible individuals.

Mould produces tiny particles called spores, which are so tiny they are invisible to the naked eye. Mould reproduces by creating spores that are carried in the air and help mould to grow and spread. All homes contain mould spores, as they enter our homes through open doors and windows or on pets, clothing and shoes. A problem occurs when mould spores come into contact with damp surfaces, which allows them to grow into mould and multiply. Mould spores need the right conditions to grow. They require water and a food source such as dust, carpet, mattresses, clothing, paper, cardboard, upholstery or drywalls. When these materials get wet from leaking plumbing or roofing, or high humidity and condensation, mould spores start to germinate and mould growth will occur within 24 to 48 hours. Warm, damp and humid conditions create the perfect breeding grounds for mould to grow.

When toxic moulds are disturbed they release poisonous mycotoxins and more mould spores. Even when the mould has been removed, mycotoxins and mould spores can still be found in the air and environment.

We can also be exposed to it through our diet. Mould can be found in certain foods such as grains, nuts, spices, coffee and dairy products; however, food mould exposure is usually only short-lived. Mould toxicity is almost always caused by exposure to mould in the home or workplace. Mycotoxin contamination of food is caused by poor growing and harvesting practices, improper food storage and damp conditions during food transportation and processing. Aflatoxins are mycotoxins produced by the Aspergillus mould species and commonly affect crops such as peanuts, corn, soybeans and tree nuts. Aflatoxin B1 is the most toxic, being classified as a carcinogen by the International Agency for Research on Cancer. Soaking, sprouting and fermenting grains, nuts and legumes has been found to significantly reduce aflatoxin levels.

How does mould affect our health?

We breathe in mould spores all the time when we are outdoors and they generally don’t cause issues; however, in sensitive people mould spores can trigger allergic reactions and respiratory problems. Some types can also colonise the nostrils, resulting in a fungal sinus infection.

Mould itself can’t enter the bloodstream. Mycotoxins on the other hand are so damaging because they can enter your bloodstream via the lungs and then circulate around the body. Mycotoxins have also been found to be able to cross the blood–brain barrier. This is why mould toxicity can cause such an array of physical and mental health issues as they can affect any system in the body. If the body can’t remove these biotoxins effectively on their own they can be stored in the body and cause long-term damage and chronic health issues.

When multiple body systems are affected it may indicate the presence of mould toxicity, which is also referred to as “sick building syndrome”. Mycotoxins can activate immune responses, resulting in chronic inflammation, which creates extensive and multiple health issues. Mycotoxins can suppress and damage the immune system, making you more susceptible to infections and illness. Studies suggest that mycotoxin exposure increases a systemic inflammatory response. People can become highly sensitive to chemicals and chronically inflamed due to their immune systems being on high alert from constantly being exposed to toxic varients in their homes. People with autoimmune diseases and compromised immune systems are particularly vulnerable to the effects of mycotoxins.

Mycotoxins can cause lung inflammation and worsen allergies and asthma and trigger chronic fatigue syndrome. They reduce beneficial microbiota in the gut and encourage pathogenic bacteria to grow and can affect cognitive function.

Common symptoms of mould toxicity

Mould symptoms can occur quickly for some people, especially if they have just moved into a new home or workplace that has an issue, or they can occur over time, as the body’s detox systems start to get overwhelmed by the continued exposure.

Mould exposure affects everyone differently: some people are more sensitive to it than others and the symptoms can range from mild to severe, and they can affect many parts of the body. Symptom severity depends on a person’s age, genetics, underlying health conditions, lifestyle and the extent of the problem and the length of time they have been exposed to it. If you are experiencing several of the following symptoms you may be suffering from mould toxicity.

  • General symptoms: Fatigue, insomnia, weight gain, hair loss, light sensitivity, intolerance to fragrances and chemicals and a metallic taste in the mouth.
  • Respiratory: Sinusitis, asthma, wheezing, shortness of breath, runny nose, sneezing, cough, inflamed nasal passages and chronic upper respiratory tract issues. People who are immunocompromised are vulnerable to getting infections in their lungs and sinuses and are more susceptible to respiratory infections such as bronchitis and pneumonia.
  • Immune system: Recurring infections, autoimmunity and allergies such as itchy watery eyes or nasal congestion.
  • Neurological symptoms: Cognitive impairment, memory loss, brain fog, vision changes, headaches, numbness and tingling, weakness, tremor, nerve pain, dizziness and light sensitivity.
  • Psychological symptoms: Anxiety, depression, OCD, anger, irritability and mood swings.
  • Musculoskeletal: Muscle cramps, joint and muscle pain, tics and muscle twitches and weakness.
  • Digestive symptoms: Nausea, abdominal pain, diarrhoea, bloating and vomiting. Mycotoxins in foods have been found to shrink intestinal villi, which can alter the gut microbiome.
  • Skin symptoms: Rashes, itchy skin and skin sensitivity.

Who is vulnerable to developing mould toxicity?

Genetics, age, nutritional deficiencies, previous accumulations of environmental toxins and long-term stress can all affect how quickly you get sick from it and mycotoxins. People with compromised immune systems or lung disease, newborns, the elderly and transplant and cancer patients are also vulnerable to mould toxicity.

Our genes can play a big part in how well we deal with mould and mycotoxin exposure. Around 25 per cent of the population have a specific HLA-DR gene variation or mutation, which makes them genetically predisposed to getting sick from mould and mycotoxin exposure. You can test for this gene variation with a HLA-DR test. The HLA-DR gene plays a crucial role in the immune system’s ability to recognise and respond to foreign substances, including toxins. A variation in this gene can impact the ability of the immune system to recognise and eliminate mycotoxins effectively and will leave a person more susceptible to experiencing adverse health effects when exposed to mould-infested environments. If you are in this susceptible population, mycotoxins can build up in the body, resulting in inflammation and damage. Even small exposure to mycotoxins can affect your health.

It’s important to note that the healthiest of people can still become ill when exposed to high enough levels of toxic mycotoxins over an extended period.

Diagnosing it’s toxicity

Mould toxicity is unfortunately often misdiagnosed and mistaken for other conditions because it has such wide-ranging effects.

Consulting with a healthcare professional who specialises in environmental medicine or mould-related illnesses is advisable to conduct a thorough evaluation and to determine the most appropriate testing approach based on your circumstances and symptoms.

There are several ways to test for mycotoxins and mould toxicity. Here are some commonly used diagnostic methods:

  • Visual contrast sensitivity (VCS) test: The VCS test is used to assess your ability to detect and distinguish subtle differences in contrast between black, white and grey objects on your computer screen. Mycotoxins impair the ability to detect subtle contrast. This test can be used as a screening tool to evaluate potential mould toxicity. A VCS test alone, however, cannot provide a definitive diagnosis of mould toxicity or determine the presence of mycotoxins in the body.
  • Visual inspection and environmental assessment: A thorough visual inspection of the living or working environment can help identify visible signs of  growth. Additionally, an environmental assessment may involve measuring humidity levels, conducting air quality tests and collecting samples from suspected mould-contaminated areas.
  • Blood tests: Specific blood tests can be conducted to assess the presence of mycotoxins or immune system responses related to mould exposure. These tests may measure inflammatory markers, antibodies and other biomarkers associated with mould toxicity.
  • Urine or biomarker analysis: Urine or biomarker tests can be utilised to detect mycotoxins or their metabolites in the body. These tests can provide valuable information about the presence and level of exposure to mould toxins.
  • Genetic testing: Genetic testing, particularly HLA–DR gene testing, can help identify specific genetic variations that may influence an individual’s susceptibility to mould-related illnesses. This testing can provide insights into an individual’s genetic predisposition and potential vulnerability to mould toxicity.

How to prevent it growing in your home

Mould commonly grows indoors, where there has been a leak and carpets or drywalls haven’t dried properly, when there is excess moisture or humidity in the air, or after heavy rain or flooding. Leaking plumbing, blocked gutters, condensation and poor air circulation in places like cupboards can cause it to grow in the home. The most common problem areas for growth are bathrooms, laundries, basements, crawl spaces and attics. Air-conditioning units, especially window units, are also notoriously mouldy and can feed the home.

It can be very difficult to detect as it can be concealed. It can often be hidden behind walls and wallpaper, under carpets or in shower inserts. Look out for water sources that are hidden such as leaking toilets, windows and roofing, which can affect baseboards, drywalls, carpets and hardwood floors.

Mould can also be mistaken for a stain or smudge as it comes in different colours like black, white, green, orange, grey and brown. If you smell a musty odour or see it in your home it is likely that you have a large mould infestation.

Maintain indoor air quality

To help maintain a clean, healthy mould-free home it is a good idea to invest in a good-quality air purifier that is designed to reduce mould. An air purifier will help filter out the spores from the air, which helps prevent their growth around your home.

Whenever possible, let fresh air and sunshine into your home by opening windows, doors and blinds. Ensuring proper airflow can help prevent growth.

Moisture control

The most important way to prevent mould growth is to keep your home dry. Quickly addressing and repairing any sources of moisture, such as leaks or condensation, is crucial in preventing infestation. Keep your bathroom dry by using an exhaust fan with a vent to the outside, and replace worn caulk around sinks, bathtubs and showers. Squeegee walls after a shower to remove moisture fast and reduce the risk of mould growth. Wooden windows are prone to mould. Wipe condensation build-up from windows after humid and wet days and remove dust from window sills that can feed spores. Check around your indoor plants for water.

Keep the humidity level in your house under 50 per cent by using a dehumidifier and air-conditioning. When humidity is over 60 per cent mould can grow. Be sure to maintain your dehumidifiers and empty and clean them regularly when in use to prevent mould growth. Don’t let humidity build up in your kitchen: use a fan to prevent steam from pots from causing it to grow behind cabinets, one of the main hiding places for mould in kitchens.

Maintain a clean home

Maintain a clean and decluttered home by minimising dust, debris and clutter, especially in higher-humidity areas like basements and bathrooms. Don’t pack your wardrobe full of clothes — allow airflow. Vacuum your carpet regularly to avoid the build-up of debris, dust, mould spores and pet dander that mould may grow on.

Removing it safely

Effective and safe cleaning practices

While bleach is commonly used as a household cleaning agent, it’s not the best or safest option for treating mould. Bleach is a strong chemical that if used in poorly ventilated areas can irritate the respiratory system and exacerbate existing health conditions such as asthma. Bleach isn’t effective at eliminating mycotoxins or spores, or the deep roots in which it grows into porous surfaces like wood, drywalls and tile grout. It does bleach mould, making it appear visually eradicated.

Undiluted white vinegar is one of the best and most effective ways to kill mould naturally. Vinegar kills spores, and if used regularly can help prevent it from coming back. Vinegar is cheap to buy and it’s safe to use in food preparation areas. Just don’t use it on marble or natural stone surfaces.

Adding essential oils such as tea tree, eucalyptus, lemon and clove with natural antifungal properties will make your natural mould cleaner smell fresh and will give it extra mould-killing powers.

Spraying undiluted 3 per cent concentration of hydrogen peroxide on it is another effective way to combat mould. Hydrogen peroxide has antifungal properties. Baking soda is another natural cleaning product that can kill mould.

DIY natural mould cleaner

1 cup white vinegar

15 drops tea tree or eucalyptus essential oil

15 drops lemon essential oil

Pour vinegar and essential oils into a spray bottle and shake well before each use.

Spray the affected area and allow it to sit for an hour before wiping the mould away with a damp clean cloth. Use a scrubbing brush on any difficult-to-remove mould. Then allow it to air dry.

You can use this spray weekly as a preventive.

Note: Remember to wear gloves and work in a well-ventilated area when using this DIY mould cleaner. While this recipe can be effective for mild cases of infestation, professional mould remediation services should be consulted for extensive or persistent issues.

Professional intervention and remediation

The best way to assess your home for a mould problem is to work with a building microbiologist. They will test the air and dust samples for moulds and mycotoxins.

Getting rid of toxic varients can be dangerous if you do it yourself, and you need to be careful that you’re not making the problem worse by spreading mycotoxins through the house while you’re treating the problem area. If the issue is localised, you should be able to remove it safely yourself. However, if the mould infestation is extensive it is recommended to hire a professional remediation company to remove it safely.

Be mindful that mycotoxins can also penetrate many household items. Non-porous items like metals and ceramics can be cleaned with a mould-removing cleaner; however, porous items like furniture, bedding and mattresses, clothes, curtains and carpets will need to be treated, cleaned or thrown out.

How to detox your body

Remove exposure

First, it is vital that you avoid mould exposure by either removing yourself and any contaminated items from your environment or using a mould remediation expert to clean up and remove it from your home. Once the source is removed you need to help your body detox from the mould and mycotoxins.

Boost gut health and detoxification pathways

To assist with mould detoxification, it is important to support your detox pathways via the kidneys, bowels and skin. It’s important to clear mycotoxins from the body, otherwise they can recycle back around the body and cause ongoing symptoms and damage. Promote regular bowel movements by drinking plenty of water and eating fibre-rich foods. Constipation can allow toxins to be reabsorbed back into circulation. Keeping well hydrated is also important to encourage detoxification through urination and sweating.

Breathing exercises, saunas and regular exercise will help increase sweating and circulation. Getting good-quality sleep is also vital as this is when the brain detoxifies via the glymphatic system.

Supporting gut health is also recommended by taking a high-quality probiotic and prebiotic supplement. Imbalances in the gut microbiome may compromise your ability to excrete mycotoxins effectively. Healthy gut microbiota bind mycotoxins to be excreted via the bowel. According to animal studies, probiotic supplementation may support mould and mycotoxin detoxification and can improve the excretion of mycotoxins.


Once your gut and detox systems are working well, look at introducing natural binders such as modified citrus pectin (MCP), activated charcoal, bentonite clay, glutathione, chlorella or humic and fulvic acid, to help clear out mycotoxins safely and effectively from the body. MCP is one of the safest and most effective toxin binders, and safe enough to use long-term.

Herbs and nutrients

Taking certain herbs and nutrients can also be beneficial in the treatment of mould toxicity. St Mary’s thistle, dandelion root and glutathione help enhance liver detoxification. Echinacea, garlic, vitamin C and zinc support immune function and help treat infections. Turmeric and omega-3 essential fatty acids have potent anti-inflammatory properties to help alleviate inflammation in the body. Gingko biloba and omega-3 fats help support cognitive function. Siberian ginseng, astragalus, Rhodiola, schizandra and cordyceps are body-balancing adaptogenic herbs that help reduce the effects of stress, such as decreased immune function and fatigue.

Mitochondria are the energy-producing powerhouses inside our cells, and they often get damaged by environmental toxins such as mycotoxins, which leads to fatigue. Nutrients that support the mitochondria include NAD (nicotinamide adenine dinucleotide), co-enzyme Q10 and phospholipids.

Detox dietary recommendations

While you are detoxing it is important to eat a balanced wholesome diet. Eat mostly plant-based, anti-inflammatory foods, including fresh colourful vegetables and fruit, preferably organic. Brassica vegetables such as broccoli, cabbage, cauliflower and kale contain sulphoraphane which assists with liver detoxification. Include foods rich in fibre including flaxseeds, chia and psyllium husks, which help improve bowel regularity and assist with removing toxins from the body. Enjoy gluten-free grains like buckwheat, brown rice and pseudograins like quinoa and amaranth. Raw seeds like flax, sunflower, chia, pumpkin or hemp, healthy fats like cold-pressed coconut oil, olive oil, avocadoes and avocado oil, and good-quality protein sources such as oily fish, organic chicken and eggs are also recommended.

Include mould-fighting spices like ginger, cinnamon, turmeric, cumin, thyme, clove and oregano and foods like garlic, onions, shallots, chives, leaks, green leafy veggies, cruciferous veggies, coconut oil, fermented foods and apple-cider vinegar with meals where you can.

Avoid inflammatory foods such as refined sugars, wheat, gluten, commercially raised red meat, fried and highly processed foods that contain refined oils and alcohol.

Fermented vegetables like sauerkraut, yoghurt, miso and kimchi and medicinal mushrooms like shiitake, maitake, oyster, cordyceps and lion’s mane also contain nutrients that are beneficial for detoxification.

Mould exposure and mould toxicity are a serious concern that demands attention to protect your health and the wellbeing of your family. With the right support, you can identify and safely resolve any long-standing mould problem. By taking proactive measures to prevent mould growth and mitigate its detrimental effects, such as incorporating moisture control and proper cleaning practices, and seeking professional help from qualified health practitioners and mould remediation specialists when needed, you can create a safe and healthy living environment that is resilient against the damaging impacts of mould.

Article Featured in WellBeing Magazine 207

Lisa Guy

Lisa Guy

Lisa Guy is a respected Sydney-based naturopath, author and passionate foodie with 16 years of clinical experience. She runs a naturopathic clinic in Rose Bay called Art of Healing and is the founder of Bodhi Organic Tea.

Lisa is a great believer that good wholesome food is one of the greatest pleasures in life and the foundation of good health. Lisa encourages her clients to get back to eating what nature intended: good, clean, wholesome food that’s nutrient-rich and free from high levels of sugars, harmful fats, artificial additives and pesticides. Her aim is to change the way people eat, cook and think about food.

Lisa is an avid health writer, being a regular contributor to The Sunday Telegraph's Body and Soul, and leading magazines including WellBeing. Lisa is an author of five books to date, including My Goodness: all you need to know about children’s health and nutrition , Pregnancy Essentials, Heal Yourself, Listen to your Body and Healthy Skin Diet .

You May Also Like

Wellbeing & Eatwell Cover Image 1001x667 2024 05 28t121831.547

Daily Rituals for Radiant Skin and Mindful Living

Wellbeing & Eatwell Cover Image 1001x667 2024 05 01t103309.503

Breaking Out of Prison: The Search For Humane Pathways

Wellbeing & Eatwell Cover Image 1001x667 2024 04 26t150309.380

Pet-friendly Herb Gardens

Wellbeing & Eatwell Cover Image 1001x667 2024 04 17t142941.179

Adapting to droughts