Is Mould Dangerous? Health Risks You Need to Know
Yes, mould is dangerous to health. The World Health Organization, Australia's National Health and Medical Research Council, and Victoria's Better Health Channel all confirm that mould exposure causes respiratory problems, allergies, and other serious health effects. Here is what you need to know.
How Mould Affects Your Health
Respiratory Issues
Mould spores and fragments irritate the airways, causing coughing, wheezing, shortness of breath, and chest tightness. Prolonged exposure can lead to chronic respiratory conditions. The Better Health Channel (VIC) lists respiratory symptoms as the most common health effect of mould exposure.
Allergic Reactions
Mould is a potent allergen. Exposure triggers histamine responses including sneezing, runny nose, watery eyes, skin rashes, and sinus congestion. Up to 10% of Australians have mould allergies, and reactions can range from mild to severe including anaphylaxis in rare cases.
Asthma Attacks
Mould is a recognised asthma trigger. The Asthma Australia foundation confirms that mould exposure can cause severe asthma attacks in sensitive individuals. Children living in mouldy homes have a significantly higher risk of developing asthma and experiencing frequent attacks.
Toxic Mould (Mycotoxins)
Certain moulds — particularly Stachybotrys chartarum (toxic black mould) — produce mycotoxins that can cause neurological symptoms, immune suppression, chronic fatigue, and serious respiratory damage. Mycotoxin exposure requires professional remediation with specialist containment protocols.
Immune System Effects
Chronic mould exposure can suppress immune function, making individuals more susceptible to infections. Immunocompromised people (cancer patients, organ transplant recipients, HIV-positive individuals) face particularly serious risks from inhaling mould spores.
Skin & Eye Irritation
Direct contact with mould or airborne spores can cause skin rashes, hives, dermatitis, and eye irritation. These symptoms often present in combination with respiratory symptoms and may be worse in rooms with visible mould growth.
Who Is Most Vulnerable?
While mould affects everyone, these groups face significantly higher health risks and should prioritise mould remediation.
Children & Infants
Developing immune systems and lungs make children particularly vulnerable. Research shows early childhood mould exposure increases lifetime asthma risk. Children breathe more air per kilogram of body weight than adults, increasing their dose of mould spores.
Elderly
Weakened immune systems and pre-existing respiratory conditions make elderly people more susceptible to mould-related illness. Mould exposure can exacerbate chronic obstructive pulmonary disease (COPD) and increase the risk of pneumonia.
Immunocompromised
People with suppressed immune systems — including cancer patients undergoing chemotherapy, organ transplant recipients, and HIV-positive individuals — face life-threatening risks from Aspergillus and other invasive mould infections.
Asthma & Allergy Sufferers
People with existing asthma or mould allergies experience amplified reactions. Mould exposure can trigger severe attacks requiring hospitalisation. Asthma Australia recommends mould removal as a critical environmental control measure.
Victorian & Australian Health References
The Better Health Channel (operated by the Victorian Department of Health) provides authoritative guidance on mould health risks. Their mould fact sheet confirms that mould can cause “allergic reactions, asthma attacks, and respiratory infections” and recommends professional removal for significant mould growth.
The Australian Institute of Health and Welfare (AIHW) identifies indoor mould as a significant environmental health hazard affecting millions of Australians, particularly in older housing stock and rental properties with deferred maintenance.
The World Health Organization (WHO) published comprehensive guidelines on indoor air quality (2009) confirming that “sufficient epidemiological evidence is available from studies conducted in different countries and under different climatic conditions to show that the occupants of damp or mouldy buildings are at increased risk of respiratory symptoms.”
When to See a Doctor
- ●Persistent cough, wheezing, or shortness of breath
- ●Worsening or new-onset asthma symptoms
- ●Recurring sinus infections or respiratory illness
- ●Unexplained chronic fatigue or headaches
- ●Skin rashes that don't respond to treatment
- ●Symptoms that improve when away from home
- ●Children with breathing difficulties or frequent illness
- ●Any symptoms in immunocompromised individuals
This information is for general awareness only and is not medical advice. Always consult a healthcare professional for health concerns.
What Should You Do About Mould?
Assess the Situation
Identify visible mould and musty odours. Note the size, location, and colour. Take photos for your records. Use our free mould risk assessment tool to evaluate your situation.
Reduce Exposure
Improve ventilation immediately. Keep affected rooms well-aired. If possible, avoid spending prolonged time in mouldy rooms — particularly children, elderly, and those with respiratory conditions.
Get Professional Help
For anything beyond small surface mould on hard surfaces, we connect you with qualified, IICRC-certified mould specialists. They can inspect, test, and remediate safely.
Fix the Cause
Mould always returns if the moisture source isn't fixed. Address condensation, leaks, ventilation, or rising damp to prevent recurrence. Our specialists can diagnose and treat the root cause.
Mould Health Risk FAQs
Concerned About Mould in Your Home?
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