Mould and Your Health: Respiratory Risks & Why Professional Treatment Matters

Most people know mould looks bad and smells worse. What many don't fully appreciate is how significantly mould exposure can affect your health — particularly with prolonged exposure in the place where you spend the most time: your home.

The health effects of mould aren't hypothetical. They're well-documented by medical research and recognised by health authorities worldwide, including the World Health Organisation and Australia's National Health and Medical Research Council. Here's what you need to know.

How mould affects your respiratory system

Mould reproduces by releasing microscopic spores into the air. These spores — invisible to the naked eye — are what you breathe in. A single mould colony can release millions of spores per day, and they're small enough to penetrate deep into your lungs.

Allergic reactions

Mould is one of the most common indoor allergens. When your immune system identifies mould spores as a threat, it triggers an inflammatory response. Symptoms include:

• Sneezing and runny nose — often mistaken for a persistent cold
• Itchy, watery eyes — particularly when spending time in the affected room
• Nasal congestion — chronic stuffiness that doesn't respond to typical cold medications
• Skin rashes and irritation — contact with mould or mould-contaminated surfaces
• Post-nasal drip and sore throat — from constant nasal inflammation

Many people live with these symptoms for months, attributing them to seasonal allergies or frequent colds, without realising their home environment is the cause. A telling sign: if your symptoms improve when you leave the house and return when you come home, indoor mould may be the culprit.

Asthma

Mould is a well-established asthma trigger. For people with existing asthma, mould exposure can cause:

• Increased frequency and severity of asthma attacks
• Worsening of chronic symptoms like wheezing and breathlessness
• Reduced effectiveness of maintenance medications
• Need for more frequent use of reliever inhalers

For children, the link is even more concerning. Research published in the Medical Journal of Australia has shown that early childhood exposure to indoor mould is associated with an increased risk of developing asthma — not just triggering existing asthma, but contributing to the initial onset of the disease.

Chronic respiratory conditions

Prolonged mould exposure can lead to more serious respiratory conditions:

• Hypersensitivity pneumonitis — inflammation of the lung tissue caused by repeated inhalation of mould spores. Symptoms include cough, shortness of breath, and fatigue
• Allergic bronchopulmonary aspergillosis (ABPA) — a condition where Aspergillus mould causes severe allergic reactions in the airways
• Chronic sinusitis — persistent sinus inflammation and infection linked to mould exposure
• Bronchitis — ongoing inflammation of the bronchial tubes

Mycotoxins: the hidden danger

Some mould species produce mycotoxins — toxic secondary metabolites that can cause harm beyond simple allergic reactions. The most concerning mycotoxin-producing species found in homes include Stachybotrys chartarum (black mould), certain Aspergillus species, and some Penicillium species.

Mycotoxin exposure can occur through inhalation, skin contact, or ingestion. Health effects may include:

• Neurological symptoms — headaches, difficulty concentrating, memory problems, dizziness
• Fatigue — chronic, unexplained tiredness that doesn't improve with rest
• Immune suppression — increased susceptibility to other infections
• Gastrointestinal issues — nausea, abdominal pain, changes in appetite

The challenge with mycotoxin exposure is that symptoms are often vague and overlap with many other conditions. This means it frequently goes undiagnosed for extended periods while the underlying exposure continues.

Vulnerable populations

While mould can affect anyone, certain groups are at significantly higher risk:

Children and infants

Children's respiratory systems are still developing, making them more susceptible to mould-related damage. Their breathing rate relative to body size is higher than adults, meaning they inhale proportionally more spores. Studies consistently show that children living in mouldy homes have higher rates of respiratory illness, asthma, and allergic conditions.

Elderly

Older adults often have reduced immune function and may have pre-existing respiratory conditions that mould exposure worsens. Symptoms of mould exposure can also be mistakenly attributed to age-related decline, delaying proper investigation.

Immunocompromised individuals

People with weakened immune systems — whether from medical conditions like HIV/AIDS, cancer treatment, organ transplantation, or immunosuppressive medications — are at risk of invasive fungal infections. Species like Aspergillus fumigatus can cause life-threatening invasive aspergillosis in immunocompromised patients.

People with existing respiratory conditions

Anyone with asthma, COPD, cystic fibrosis, or other chronic respiratory conditions will typically experience worsening symptoms with mould exposure.

Why professional treatment matters

Understanding the health risks of mould explains why proper treatment — not just a quick wipe with bleach — is essential.

Surface cleaning doesn't eliminate the problem

DIY cleaning removes visible mould but rarely addresses spores embedded in porous materials or circulating in the air. Within weeks, the mould regrows from surviving spore colonies, and the health exposure continues.

Disturbing mould without containment makes it worse

Scrubbing, scraping, or vacuuming mould without proper containment sends a massive burst of spores into the air. This can temporarily increase your exposure dramatically and spread mould to previously unaffected areas of the home.

Airborne spores need active treatment

Even after visible mould is removed, elevated spore counts in the air can persist for weeks or months. Professional treatment addresses both the visible colonies and the airborne spore load.

At Pureairo, our approach uses SAN-AIR technology — a plant-based, chemical-free solution independently validated by UNSW and Eurofins testing — to reduce airborne mould spores throughout the property. Unlike chemical treatments that can introduce their own health risks, SAN-AIR works continuously to suppress spore counts and improve indoor air quality without harmful residues.

Take mould seriously

If you're experiencing persistent respiratory symptoms, unexplained allergies, or chronic fatigue — and you've noticed mould or musty odours in your home — the two may well be connected.

We offer free assessments across the Sydney metro area to evaluate your mould situation and recommend the right course of action. Whether it's a minor issue you can manage yourself or a problem that needs professional remediation, we'll give you an honest, no-obligation answer. Contact us to book your free assessment.