Can Mould Cause Asthma?

Respiratory issues are relatively common in the UK, with asthma affecting approximately 12% of the population. In this blog, we’ll explore the relationship between mould and asthma, examining the research behind the all-important question – can mould cause asthma?

Managing asthma can be challenging as it is easily triggered by a wide range of substances, including common household issues like mould. For those with lung conditions, it is important to avoid exposure to these triggers whenever possible.

Disturbing mould can release harmful spores into the air, which is why attempting to remove mould yourself is never recommended.

When it comes to safe and effective mould removal, Rainbow Restoration offers professional services that provide vital support for those suffering from respiratory issues. If you have a mould problem and need expert assistance, don’t hesitate to contact us – our teams are ready to help.

To fully address the question “Can mould cause asthma?”, it is important to first understand what mould is and the potential health implications of exposure. By exploring the connection between mould and asthma, we can set the stage for a deeper understanding of how mould can impact respiratory health and why professional intervention may be necessary.

What is Mould?

Mould is a type of fungus that thrives when a damp, moisture-rich environment and an organic food source are both present. Under these conditions, mould spores can germinate and spread rapidly, particularly when temperatures range between 20ºC and 27ºC, air circulation is limited and relative humidity (RH) exceeds 70%.

These ideal conditions allow mould to proliferate quickly, posing potential health risks and structural concerns within a property. Different types of mould can thrive in such environments, including some that are known to produce mycotoxins, which can be harmful to health.

Some common types of mould you might encounter in your property include:

• Alternaria – Usually dark green and woolly, commonly appears around baths, sinks and windows.
• Aspergillus – Either yellow-green or white and with a powdery appearance, typically found thriving in oxygen-rich environments.
• Chaetomium – Usually green or black with a cotton texture, frequently found in damp or water-damaged properties.
• Penicillium – Blue or green and with a velvety appearance, often found on spoiled food.
• Stachybotrys Chartarum – Otherwise known as ‘black mould’, and has a black and slimy appearance, typically found in humid environments and on cellulose-rich materials.
• Ulocladium – Dark brown or black with a powdery appearance, often seen in damp areas after flooding.

Whilst there are over 100,000 known species of fungi globally, researchers have identified 81 common types of mould present in British homes. Those that are often classed as harmful to humans are divided into three groups: allergenic, pathogenic and toxigenic.

How Can Mould Effect Your Health?

The type and amount of mould, the way you’re exposed to it and your overall health all play a significant role in how your body reacts to mould exposure.

For instance, ingesting mould typically poses a greater health risk than skin contact. Those with a weakened immune system, including individuals with immunosuppressive disorders, obesity, the young and the elderly, are more likely to experience negative health effects from mould exposure.

A mould allergy often presents with cold-like symptoms such as sneezing, coughing or a blocked nose – especially in warm or damp environments. Symptoms of mould exposure can include, but are not restricted to:

• Shortness of breath (dyspnoea)
• Coughing
• Wheezing
• Tightness in the chest
• Congestion
• Fatigue
• Irritated eyes
• Sore throat
• Fever
• Lung, throat and sinus infections
• Seizures

For those with allergies, anaphylaxis is a life-threatening reaction that could be triggered by exposure to mould. If you have known allergies, it’s important to remain vigilant for any symptoms and to contact emergency services immediately if you suspect exposure.

In our blog, The Dangers of Sleeping in a Room with Mould, we explore the serious health implications of mould exposure, particularly for vulnerable groups and examine the role of legislation like Awaab’s Law in protecting those at risk

How Common are Mould Problems in England?

Determining the exact prevalence of damp and mould in British homes can be challenging due to variations in reporting and measurement methods. However, UK Government statistics estimate that between 4% and 27% of homes in England alone.

At the lower end of this range, this would mean around 2 million people are living in mould-affected homes, highlighting a significant public health concern.

What is Asthma?

Asthma is a chronic respiratory condition characterised by inflammation of the lungs and airways. Common symptoms include coughing, wheezing and shortness of breath as a result of constricted airways and excess mucus production.

What Causes Asthma?

Although the exact cause of asthma remains unknown, studies indicate it develops due to a mix of contributing factors. Research suggests genetics play a role – with some individuals having a hereditary predisposition – however, environmental factors and irritants may also influence its development.

Whilst asthma has genetic markers, more than 100 genes have been identified as potential risk factors, indicating that there is no single universal cause or trigger.

According to statistics published by the NHS from 2023, around 5.4 million people in the UK are receiving treatment for asthma, making it a relatively common condition. However, its consequences can still be severe, with Asthma + Lung UK reporting that around four people die each day, two-thirds of which being preventable.

What Environmental Factors Affect Asthma?

There are a wide range of environmental factors which have been observed to trigger asthma, some of which are common exposures and others depend on lifestyle and occupational choices.

Common asthma triggers include air pollution, mould, cold air and allergies to substances such as pet dander or dust mites. Additionally, lifestyle and occupational factors can contribute to asthma flare-ups, with triggers such as smoking, exposure to fumes, gases, dust and other chemical irritants playing a significant role.

Research indicates a strong link between socio-economic status and asthma risk, with deprived communities experiencing higher prevalence rates.

Can Mould Cause Asthma?

Research consistently suggests that mould exposure can trigger asthma and, in some cases, contribute to the development of the condition, particularly with prolonged exposure. According to a recent survey by Asthma + Lung UK, approximately 43% of asthma sufferers in England identified mould as a trigger for their condition.

Whilst there has been no single, definitive trigger identified for asthma, numerous peer-reviewed studies have demonstrated significant links between mould exposure and asthma development.

A meta-analysis conducted in 2012 and published in the Public Library of Science titled “Residential Dampness and Molds and the Risk of Developing Asthma” found a significant association between visible mould, mould odour and new-onset asthma. The research highlighted how specific indicators of indoor mould could play a role in asthma development.

Similarly, a 2018 literature review, “Indoor Mould Exposure, Asthma and Rhinitis,” focused on the impact of visible mould and mould odour on asthma development, particularly in children. The study revealed a clear link between mould exposure and the exacerbation of asthma symptoms, underlining the vulnerability of younger populations to indoor air pollutants.

However, despite identifying this link, the researchers emphasised that more evidence is needed to conclusively establish a causal relationship in adults, highlighting the need for further research.

A 2019 study titled “Exposure to Indoor Mouldy Odour Increases the Risk of Asthma in Older Adults Living in Social Housing” reinforced the serious health risks associated with mould exposure, citing compelling evidence that exposure to indoor dampness and fungal contamination can lead to a 30% to 50% increased risk of developing asthma.

Additional research from the Air Quality and Public Health team, presented in “The Burden of Respiratory Disease from Formaldehyde, Damp and Mould in English Housing,” aimed to quantify the burden of disease to inform government policy. In 2019 alone, the study attributed 5,000 new asthma cases and 8,500 lower respiratory infections to damp and mould exposure.

Notably, the findings revealed that ethnic minorities and disadvantaged groups were disproportionately impacted, highlighting a significant public health disparity.

Collectively, these studies strengthen the evidence linking mould exposure to asthma in vulnerable populations and highlight the urgent need for improved indoor air quality to support better respiratory health.

How to Prevent Mould Growth

One of the most effective ways to prevent mould is to eliminate the conditions in which it thrives. Since mould typically grows in damp and humid environments, it is important to focus your efforts on managing moisture and ventilation in these areas of your home.

According to the Anaphylaxis Campaign, mould itself does not directly cause irritation. Instead, it is the spores released by mould when temperatures rise sharply in a damp environment, such as when the heating is turned on, that trigger allergic reactions.

If you have a mould allergy or sensitivity that affects your asthma, there are several practical steps you can take to reduce its impact:

• Ensure your home is well-ventilated by opening windows regularly and using extractor fans in damp-prone areas such as the kitchen and bathroom. Proper ventilation reduces moisture build-up and minimises the risk of mould growth.
• Control indoor moisture by fixing leaks promptly and checking that sealants around windows, doors and plumbing are intact. When using a clothes dryer, make sure the room is well-ventilated to prevent excess moisture.
• Maintain a regular cleaning routine to prevent mould growth. Focus on damp-prone areas like bathrooms, kitchens and windowsills. Use mould resistant cleaning products to provide extra protection.
• Avoid outdoor areas with a high likelihood of mould growth, such as woodlands, parks and gardens, particularly in autumn when fallen leaves can harbour mould spores.
• Manage your asthma proactively by consistently taking your preventer medication as prescribed. Always carry your inhaler with you when going out, ensuring you are prepared for potential triggers.
• Dehumidifiers are an excellent choice for reducing moisture levels within a property. There are a variety of options available to suit different budgets, ranging from affordable damp crystals to more effective electric-powered dehumidifiers.

For further guidance, we’d recommend reading advice provided by AllergyUK.

If you suspect that mould in your home is triggering your asthma, it is important not to attempt to remove it yourself. Guidance provided by the NHS suggests if the mould covers an area larger than one square metre, you should contact a professional mould removal company to handle the situation safely and effectively.

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If the mould patch in your home is smaller than 1m² and you have a healthy individual – such as yourself, a friend or family member without any respiratory conditions – who could assist, you can find detailed guidance in our blog on how to remove mould safely and effectively.

However, if you need professional help, Rainbow Restoration is here to support you. With national coverage, we have a branch situated on average just 23 miles from any postcode within the UK.

Our specialist mould removal service not only eliminates existing mould but also identifies the underlying causes, ensuring a long-term solution. Our highly trained technicians have years of experience, offering safe and effective mould removal while advising you on the best practices to prevent mould from returning.

Our National Helpline is available 24/7, 365 days a year, so please do not hesitate to contact us on 01623 422488.