Infographic showing how damp homes and poor ventilation lead to mould, microbes and respiratory health problems

Damp Homes, Indoor Air and Health: What a Recent Evidence Review Tells Us

Infographic showing how damp homes and poor ventilation lead to mould, microbes and respiratory health problems
How dampness and poor ventilation can increase mould and affect the air we breathe indoors.

Summary: A recent rapid review by researchers from the Health and Safety Executive examined evidence on microbiological hazards in buildings, including moulds, bacteria and viruses. The review highlights that dampness, poor ventilation and building design can all affect indoor air quality and respiratory health.

Key points

  • People spend much of their time indoors, so indoor air quality can strongly affect health.
  • Damp indoor conditions increase the risk of mould growth and musty odours.
  • Common indoor moulds include Aspergillus, Penicillium and Cladosporium.
  • Dampness and visible or hidden mould are linked with asthma, rhinitis, wheeze and other respiratory symptoms.
  • Ventilation is one of the most important ways to reduce moisture and dilute airborne contaminants.
  • Improving energy efficiency is important, but very airtight homes still need adequate ventilation.

Contents

Why indoor air matters

Most of us spend a large amount of time indoors — at home, at work, or in public buildings. The air inside buildings can contain particles from many sources, including dust, mould spores, bacteria, viruses, cooking, cleaning products, pets and outdoor air entering the home.

The recent review, Exposure Risks from Microbiological Hazards in Buildings and Their Control — A Rapid Review of the Evidence, looked at evidence for harmful microorganisms in indoor air and on surfaces, and how building design, ventilation and moisture affect exposure.

What the review found

The review found strong evidence that microorganisms can be present in indoor air and on surfaces. These include fungi, bacteria and viruses. The evidence was strongest for the role of dampness and poor ventilation in increasing the risk of indoor mould growth and respiratory health effects.

The review’s main conclusions included:

  • Airborne allergenic fungi are well documented in indoor air.
  • Damp conditions increase mould growth and mouldy odours indoors.
  • Dampness and mould are associated with respiratory ill health, including asthma, rhinitis and wheezing.
  • Penicillium, Aspergillus and Cladosporium are commonly detected in damp buildings.
  • Infectious viruses and bacteria can also be detected in indoor air and on surfaces.
  • Ventilation is a key control measure for reducing moisture and diluting airborne contaminants.

Damp, mould and lung health

Dampness is one of the most important drivers of indoor mould growth. Moisture can come from leaks, condensation, flooding, poor insulation, inadequate heating, drying clothes indoors, cooking, showering, or poor ventilation.

When dampness persists, mould can colonise indoor materials such as plasterboard, wallpaper, wood, carpets, soft furnishings and settled dust. Mould may be visible, but it can also grow in hidden areas such as behind furniture, inside wall cavities, behind wallpaper, under flooring, or around poorly ventilated cold surfaces.

Exposure to damp and mould has been linked with:

  • Wheezing
  • Asthma symptoms or asthma worsening
  • Rhinitis and nasal symptoms
  • Cough
  • Respiratory infections
  • Worsening symptoms in people with existing lung disease

Importantly, the review notes that the relationship between indoor microorganisms and health is complex. Risk depends on the type of organism, the level of exposure, the building conditions and the susceptibility of the person exposed.

Aspergillus and aspergillosis

Aspergillus is a common mould found in the environment. Most people inhale Aspergillus spores every day without becoming ill. However, some people are more vulnerable, including those with asthma, bronchiectasis, chronic lung disease, weakened immune systems, or previous lung damage.

In susceptible people, exposure to Aspergillus may contribute to conditions such as allergic bronchopulmonary aspergillosis (ABPA), severe asthma with fungal sensitisation (SAFS), aspergillus bronchitis, or chronic pulmonary aspergillosis (CPA). The home environment is not the only source of exposure, but damp indoor spaces may increase the amount of fungal material a person breathes in.

This does not mean that every damp home causes aspergillosis, or that every person exposed to mould will become ill. It does mean that reducing dampness, improving ventilation and addressing visible or hidden mould are sensible steps for respiratory health.

Ventilation and building design

One of the strongest messages from the review is that ventilation is central to controlling indoor microbiological risk. Ventilation helps by:

  • Removing moisture from indoor air
  • Reducing condensation
  • Diluting airborne mould spores and other particles
  • Reducing the build-up of infectious aerosols
  • Improving overall indoor air quality

The review also highlights an important modern problem. Homes are increasingly designed or retrofitted to be more airtight and energy efficient. This can improve warmth and reduce energy use, but if ventilation is inadequate, moisture and airborne contaminants may accumulate indoors.

In other words, insulation and energy efficiency are important, but they need to be balanced with effective ventilation and moisture control.

What can help reduce risk?

The review does not suggest that one single action solves all indoor air problems. Instead, it supports a combined approach.

1. Reduce moisture

  • Repair leaks promptly.
  • Check roofs, gutters, pipes and window seals.
  • Use extractor fans in kitchens and bathrooms where available.
  • Avoid drying clothes indoors where possible, or ventilate well if you do.
  • Reduce condensation on windows and cold walls.

2. Improve ventilation

  • Use trickle vents if fitted.
  • Open windows when safe and practical.
  • Use mechanical ventilation systems correctly.
  • Keep air bricks and vents clear.
  • Make sure extractor fans are working effectively.

3. Deal with mould safely

  • Small areas of surface mould may be cleaned carefully using appropriate household methods.
  • Large, persistent or recurring mould usually needs the underlying damp problem fixed.
  • People with significant lung disease, immune suppression or severe symptoms should avoid heavy mould disturbance and seek advice.

4. Reduce dust reservoirs

  • Regular cleaning can reduce settled dust and spores.
  • HEPA-filter vacuum cleaners may be helpful for some households.
  • Hard flooring may be easier to keep dust-free than carpets in high-risk situations.

5. Consider air filtration where appropriate

Portable high-efficiency particulate air (HEPA) filters may help reduce airborne particles in some settings. They are not a substitute for fixing damp or improving ventilation, but they may be a useful additional measure for some people.

Help us understand damp homes and health

The evidence linking damp homes, mould and respiratory health is strong, but there are still important unanswered questions. We need to better understand how different homes, building types, ventilation patterns and damp conditions affect people’s health in real life.

The National Aspergillosis Centre is running a UK citizen science study looking at damp homes and health.

We are inviting people to register their interest in taking part.

The study is open to people with and without lung conditions, and to people living in homes with or without damp or mould. This comparison is important because it helps researchers understand which factors are most strongly linked with health outcomes.

Register your interest in the damp homes and health study

Taking part may involve completing a questionnaire and, at a later stage, providing a dust sample from your home. The information gathered will help improve understanding of indoor environments and respiratory health.

When to seek medical advice

Please seek medical advice if you have:

  • New or worsening breathlessness
  • Chest pain
  • Coughing up blood
  • Persistent fever
  • Repeated chest infections
  • Rapidly worsening asthma symptoms
  • Unexplained weight loss or severe fatigue

If you already have aspergillosis, asthma, bronchiectasis, chronic obstructive pulmonary disease (COPD), immune suppression, or another lung condition, it is worth discussing any significant damp or mould exposure with your healthcare team.

Common questions

Can mould affect health even if I cannot see it?

Yes. Hidden mould or dampness may still affect indoor air quality. A musty smell, persistent condensation or symptoms that worsen in a particular room may suggest a problem.

Does all mould cause aspergillosis?

No. Mould exposure is common, and most people do not develop aspergillosis. Aspergillosis usually occurs when exposure combines with individual susceptibility, such as asthma, bronchiectasis, immune suppression or existing lung damage.

Is ventilation always good?

Ventilation is usually important for reducing moisture and improving indoor air quality. However, the best approach depends on the building, outdoor conditions and the person’s health. Ventilation should not replace fixing leaks or removing sources of damp.

Can air purifiers solve damp and mould problems?

No. Air purifiers may reduce airborne particles, but they do not remove the source of moisture or mould growth. Damp problems need to be addressed at source.

Summary

This recent evidence review reinforces a practical message: indoor air quality matters. Dampness, poor ventilation and mould growth are not simply cosmetic housing problems — they can affect respiratory health, especially in people with asthma, aspergillosis or other lung conditions.

The most effective approach is to reduce moisture, improve ventilation, remove mould sources where possible and understand how buildings influence exposure. Research such as the UK damp homes and health study will help build better evidence for patients, clinicians, housing providers and policymakers.

References and further reading

Article type: Patient and public information

Last reviewed: April 2026

Based on: Recent evidence review of microbiological hazards in buildings and their control.

by GAtherton

Help us understand how damp homes affect health

We are supporting a UK research project looking at how damp homes may affect health, including respiratory health and conditions such as aspergillosis.

This study is being led by the National Aspergillosis Centre at Manchester University NHS Foundation Trust, and is being shared through aspergillosis.org to support research into damp homes and health.

We are currently inviting people across the UK to register their interest in taking part.

Registering your interest should take less than one minute and does not commit you to taking part.


Register your interest now

Why this matters

Damp and mould are often linked to health problems, but there is still limited real-world evidence from people’s homes across the UK.

This project aims to help improve understanding of how home environments may affect health by gathering information from people living in a wide range of housing conditions.

Who can register interest?

We would like to hear from people living in the UK, including:

  • people with lung or respiratory conditions
  • people without any known lung or breathing condition
  • people who have experienced damp or mould at home
  • people who have not experienced damp or mould at home
  • members of the general public who would like to contribute to the research

We are keen to hear from people with different health backgrounds and a wide range of home environments.

What is the study about?

This research is exploring how damp homes may affect health. The aim is to improve understanding of the relationship between home environments and health symptoms in real-world settings.

This project is for research purposes only and does not provide medical advice or diagnosis.

What might taking part involve later?

If the study opens, some people who register interest may later be invited to:

  • complete a short questionnaire about their home and health symptoms
  • receive a simple home sampling kit by post
  • collect and return a small household sample, for example dust from the home, for research purposes

The home sampling part is intended to be simple and practical. Full instructions would be provided.

Registering your interest now does not commit you to taking part later.

Important information

  • Registering interest is voluntary.
  • You do not have to take part in the full study later.
  • Your details will only be used to contact you about this project.
  • Your data will be handled in line with UK data protection regulations.
  • You can decide later whether or not to take part.

Frequently asked questions

Am I signing up to take part in the study now?

No. At this stage, you are only registering your interest in hearing more about the study.

Do I need to have a lung condition to register interest?

No. We would like to hear from people with and without lung conditions.

Do I need to have damp or mould in my home?

No. We are interested in hearing from people with a wide range of home environments and experiences.

Will I definitely receive a kit?

Not necessarily. Registering interest helps the research team understand the level of interest and contact people if the study opens.

Will I get personal results about my home or health?

At this stage, no individual results are being promised. More information would be provided if the study proceeds.

What happens after I register interest?

You do not need to do anything further straight away. If the study opens, you may be contacted with more information so you can decide whether you would like to take part.

Register your interest

Ready to help? Complete the form below.

This secure form should take less than one minute to complete.

If the form does not load, you can open it here:

Open the form in a new window

by GAtherton

Help us understand how damp homes affect health

We are supporting a UK research project looking at how damp homes may affect health, including respiratory health and conditions such as aspergillosis.

This study is being led by the National Aspergillosis Centre at Manchester University NHS Foundation Trust, and is being shared through aspergillosis.org to support research into damp homes and health.

We are currently inviting people across the UK to register their interest in taking part.

Registering your interest should take less than one minute and does not commit you to taking part.


Register your interest now

Why this matters

Damp and mould are often linked to health problems, but there is still limited real-world evidence from people’s homes across the UK.

This project aims to help improve understanding of how home environments may affect health by gathering information from people living in a wide range of housing conditions.

Who can register interest?

We would like to hear from people living in the UK, including:

  • people with lung or respiratory conditions
  • people without any known lung or breathing condition
  • people who have experienced damp or mould at home
  • people who have not experienced damp or mould at home
  • members of the general public who would like to contribute to the research

We are keen to hear from people with different health backgrounds and a wide range of home environments.

What is the study about?

This research is exploring how damp homes may affect health. The aim is to improve understanding of the relationship between home environments and health symptoms in real-world settings.

This project is for research purposes only and does not provide medical advice or diagnosis.

What might taking part involve later?

If the study opens, some people who register interest may later be invited to:

  • complete a short questionnaire about their home and health symptoms
  • receive a simple home sampling kit by post
  • collect and return a small household sample, for example dust from the home, for research purposes

The home sampling part is intended to be simple and practical. Full instructions would be provided.

Registering your interest now does not commit you to taking part later.

Important information

  • Registering interest is voluntary.
  • You do not have to take part in the full study later.
  • Your details will only be used to contact you about this project.
  • Your data will be handled in line with UK data protection regulations.
  • You can decide later whether or not to take part.

Frequently asked questions

Am I signing up to take part in the study now?

No. At this stage, you are only registering your interest in hearing more about the study.

Do I need to have a lung condition to register interest?

No. We would like to hear from people with and without lung conditions.

Do I need to have damp or mould in my home?

No. We are interested in hearing from people with a wide range of home environments and experiences.

Will I definitely receive a kit?

Not necessarily. Registering interest helps the research team understand the level of interest and contact people if the study opens.

Will I get personal results about my home or health?

At this stage, no individual results are being promised. More information would be provided if the study proceeds.

What happens after I register interest?

You do not need to do anything further straight away. If the study opens, you may be contacted with more information so you can decide whether you would like to take part.

Register your interest

Ready to help? Complete the form below.

This secure form should take less than one minute to complete.

If the form does not load, you can open it here:

Open the form in a new window

by GAtherton

Mould, “Toxins” and Aspergillus: Understanding What’s True and What Isn’t

Last reviewed: April 2026

Key points

  • Exposure to mould is not the same as having aspergillosis.
  • Aspergillus is a common environmental fungus that most people inhale daily.
  • “Mycotoxin” and “detox” explanations are common online but are not part of standard diagnosis.
  • Symptoms usually arise from a combination of lung disease, infection, inflammation, and environment.
  • Diagnosis relies on clinical tests (scans, blood tests, microbiology), not environmental testing alone.
  • Specialist home testing is sometimes used—but only in specific clinical situations.

A guide for patients and carers

Many people with lung conditions come across information linking mould exposure, toxins, and Aspergillus infections. Some of this information can be helpful—but much of it can also be confusing.

This article explains the most common misunderstandings and what current medical practice actually relies on.

Important: Some tests measure exposure—but medical diagnosis requires evidence of disease.

Contents

Why this topic is confusing

  • Mould is visible and easy to focus on
  • Symptoms (fatigue, cough, breathlessness) are non-specific
  • Online information often mixes different conditions together

This can lead to the idea that one single cause—such as “mould toxicity”—explains everything. In practice, respiratory conditions are usually more complex.

Mould exposure vs Aspergillus disease

Mould exposure

  • Common in homes and outdoor air
  • Can irritate airways
  • May worsen symptoms

Aspergillus disease

  • Occurs in specific medical contexts
  • Related to lung structure and immune response
  • Requires clinical diagnosis
Being exposed to mould does not mean you will develop aspergillosis.

Important context: Aspergillus spores are present in the air we breathe every day. Most people inhale them without developing disease.

Mycotoxins and “detox” claims

You may see references to:

  • “Mycotoxin illness”
  • “Die-off reactions”
  • “Binders” to remove toxins

These ideas are widely discussed online, but they are not part of standard medical diagnosis or treatment for Aspergillus lung conditions.

This does not mean symptoms are not real. It means they are usually explained through:

  • Inflammation
  • Infection
  • Underlying lung disease

Why “mould toxin tests” are not used diagnostically

Exposure is common

Many people have detectable environmental exposure, so results are not specific.

Results do not match symptoms reliably

Levels do not consistently correlate with disease or severity.

Lack of standardisation

Different labs use different methods, making interpretation difficult.

Not part of clinical guidelines

Major respiratory guidelines do not include these tests in diagnosing Aspergillus conditions.

Risk of confusion

  • May cause unnecessary concern
  • May lead to unproven treatments
These tests may detect exposure—but they do not diagnose Aspergillus disease.

Why symptoms don’t have one single cause

Symptoms often arise from a combination of:

  • Underlying lung disease
  • Inflammation
  • Infection (fungal or bacterial)
  • Environmental triggers (pollution, damp)

This is why symptoms can fluctuate and may not respond to a single explanation or treatment.

How Aspergillus conditions are actually diagnosed

Diagnosis is based on a combination of:

  • CT imaging
  • Blood tests (e.g. IgE, IgG)
  • Microbiology (sputum or bronchoscopy)

Environmental testing alone is not sufficient to diagnose disease.

When home testing may be used

In some cases, specialist teams (for example via the Mycology Reference Centre Manchester) may arrange targeted environmental sampling.

This is different from commercial testing and focuses on:

  • Specific clinically relevant fungi (e.g. Aspergillus species)
  • Known allergens or pathogens

Why it is done

  • Established Aspergillus-related disease
  • Unexplained or persistent symptoms
  • Concern about ongoing exposure

This testing is used to answer specific clinical questions and is interpreted alongside medical findings.

Specialist home testing is selective and clinically guided—not a routine diagnostic tool.

What matters most for patients

  • Work with your clinical team for diagnosis and treatment
  • Address damp and mould in your home
  • Focus on practical steps that improve symptoms
  • Avoid relying on a single explanation for complex symptoms

Final takeaway

Mould, environment, and Aspergillus are connected—but not in a simple cause-and-effect way.

Understanding this helps you focus on what is most likely to improve your health: appropriate treatment, good living conditions, and ongoing monitoring.

Author: aspergillosis.org

Note: Educational content only – not medical advice.

by GAtherton

Indoor Air Quality, Damp, Mould and Aspergillus

Last reviewed: April 2026

Key points

  • Indoor air problems usually relate to pollution, damp, or mould—these are different but can overlap.
  • Aspergillus is a normal part of the environment and not automatically a sign of a problem indoors.
  • Damp and mould can worsen breathing symptoms and should be taken seriously.
  • Fixing the underlying moisture problem is more important than cleaning visible mould.
  • Knowing who to contact (GP, landlord, council) is key to resolving problems.

Indoor Air Quality, Damp, Mould and Aspergillus

A practical guide for patients

Many people with aspergillosis or other lung conditions are concerned about the air inside their home. This article explains how indoor air quality works, how to recognise problems, and what steps you can take to improve your environment.

Contents

What affects indoor air?

Indoor air quality is influenced by both indoor and outdoor factors. People spend most of their time indoors, so even small issues can have a noticeable effect on health. :contentReference[oaicite:0]{index=0}

Indoor air can be affected by:

  • Outdoor pollution entering the building
  • Damp and moisture
  • Mould growth
  • Cooking, heating, and cleaning products
  • Dust and particles

Three common indoor air problems

1. Indoor air pollution

  • Particles from cooking, heating, and candles
  • Outdoor pollution enters indoors

2. Damp (moisture)

  • Condensation, leaks, poor ventilation
  • Creates conditions for mould growth

3. Mould

  • Visible fungal growth on surfaces
  • Releases spores into the air
These problems often occur together—but they are not the same thing.

Aspergillus in the home

Aspergillus is a common environmental fungus found in air, dust, and soil.

This means:

  • Everyone breathes in Aspergillus spores regularly
  • Indoor exposure is not unusual

Important: Exposure does not equal disease. Aspergillosis depends on lung health and immune response—not just environment.

Damp and mould

Damp and mould are important because they can affect respiratory health. Damp homes are linked with increased respiratory symptoms and illness. :contentReference[oaicite:1]{index=1}

UK guidance highlights that damp and mould can produce irritants and spores that affect the lungs and should be addressed promptly. :contentReference[oaicite:2]{index=2}

Symptoms and health effects

Indoor air problems may contribute to:

  • Cough
  • Breathlessness
  • Wheeze
  • Chest tightness
  • Fatigue

These symptoms often overlap with infection or underlying disease, making them difficult to interpret.

Identifying problems

Signs of damp

  • Condensation on windows
  • Cold or damp walls
  • Peeling paint or wallpaper
  • Musty smell

Signs of mould

  • Black or green patches
  • Mould returning after cleaning
  • Growth behind furniture or in corners

Hidden issues

  • Persistent damp smell
  • Symptoms are worse in certain rooms
If mould keeps returning, there is usually an underlying moisture problem.

Getting the right help

1. Your healthcare team

  • If symptoms worsen
  • If you suspect your environment is affecting your health

2. Landlord or housing provider

  • Report problems early
  • Keep records (photos, dates)

UK guidance makes clear that damp and mould should be addressed promptly and not ignored.

3. Local council

  • If landlord does not act
  • If health is affected

Further reading

See more detailed guidance and support resources here:
Housing, damp and mould articles (aspergillosis.org)

Practical steps

  • Improve ventilation (especially kitchens and bathrooms)
  • Reduce moisture
  • Address leaks quickly
  • Clean small mould areas safely

Air purifiers

Air purifiers can reduce airborne particles, but:

  • They do not fix damp
  • They do not remove mould from surfaces
  • They do not treat aspergillosis

Final takeaway

Indoor air problems are common and often manageable. The key is to:

  • Recognise the signs early
  • Address moisture and mould properly
  • Seek help when needed

Author: aspergillosis.org

Note: This article is for general education and does not replace medical advice.

by GAtherton

Outdoor Air Pollution and Aspergillosis

Last reviewed: April 2026

Key points

  • Harmful air pollution can be visible or invisible.
  • The Air Quality Index (AQI) is more reliable than how the air looks.
  • Air pollution comes from natural, industrial, and everyday urban sources.
  • Staying indoors can reduce exposure, but it does not remove it completely.
  • People with aspergillosis, asthma, or bronchiectasis may be more sensitive to polluted air.
  • Simple steps such as checking AQI, closing windows, and using filtration can help reduce exposure.

A practical guide for patients with lung conditions

Air pollution can make breathing symptoms worse for many people, especially those with existing lung disease. If you live with aspergillosis, asthma, bronchiectasis, chronic obstructive pulmonary disease (COPD), or other long-term lung problems, outdoor air quality can make a noticeable difference to how you feel day to day.

This guide explains what outdoor air pollution is, where it comes from, how to judge risk, what practical steps may help reduce exposure, and how to think sensibly about buying an air purifier.

Contents

What is outdoor air pollution?

Outdoor air pollution is a mixture of particles and gases in the air that can irritate the lungs and worsen breathing symptoms.

The main pollutants discussed in health guidance include:

  • PM2.5 – very fine particles small enough to travel deep into the lungs
  • PM10 – slightly larger particles that can still irritate the airways
  • Nitrogen dioxide (NO2) – often linked to traffic and combustion
  • Ozone (O3) – a gas that can irritate the lungs, especially in hot weather
  • Smoke, dust and soot – depending on local conditions

Some of these pollutants are easy to see, but some are not. This is one reason why it is important not to rely only on appearance when judging air quality.

Where does it come from?

Outdoor air pollution usually comes from a combination of sources, not just one.

Natural sources

  • Desert dust or sandstorms
  • Wildfire smoke
  • Wind-blown soil and dust
  • Pollen (not usually included in AQI in the same way, but still relevant for symptoms)

Commercial and industrial sources

  • Factories
  • Power stations
  • Shipping emissions
  • Aviation emissions
  • Construction and demolition dust

Domestic and urban sources

  • Road traffic
  • Heating systems
  • Wood burners and solid fuel burning
  • Cooking emissions in densely populated areas

In some situations, one source clearly dominates. For example, a severe dust event in North Africa or the Middle East may be mainly caused by natural desert dust. In a busy city, day-to-day pollution may be more strongly linked to traffic, heating, and industry. In many real-life situations, however, several sources are contributing at the same time.

Visible or invisible pollution

One of the most important things for patients to know is that harmful air pollution can be visible or invisible.

Visible pollution

  • Dust or sand in the air
  • Smoke
  • Grey or brown smog
  • Heavy haze

Invisible pollution

  • Fine particles such as PM2.5
  • Gases such as ozone or nitrogen dioxide

Clear sky does not always mean clean air. Equally, hazy air is not always the only dangerous situation. Some invisible pollutants can be especially harmful because they are easy to miss and can still reach deep into the lungs.

Key message: If you can see it, it may be harmful. If you cannot see it, it still may be harmful.

Understanding AQI (Air Quality Index)

The Air Quality Index (AQI) is often the most useful practical tool for patients. It gives a simple way of describing how healthy or unhealthy the air is likely to be.

AQI Meaning
0–50 Good
51–100 Moderate
101–150 Unhealthy for sensitive groups
151–200 Unhealthy
201–300 Very unhealthy
300+ Hazardous

Very high readings can occur in severe dust events, smoke events, or heavily polluted urban conditions. For patients with lung disease, even levels well below the highest categories may still trigger symptoms.

Why AQI matters more than appearance

AQI can help you judge risk more reliably than what you can see or smell. Dust may have no obvious smell. Fine particles may be invisible. Air that looks like fog may actually be carrying a heavy particle load. Because of this, it is usually safer to trust the AQI reading rather than appearance alone.

Where to check AQI

Reliable sources for checking air quality include:

For most people, it is best to use one app consistently, and occasionally cross-check with a second source if readings seem unusual.

Why air pollution matters in aspergillosis

People living with aspergillosis may already have lungs that are inflamed, structurally damaged, or more easily irritated. This may include people with:

  • Allergic bronchopulmonary aspergillosis (ABPA)
  • Chronic pulmonary aspergillosis (CPA)
  • Bronchiectasis
  • Asthma
  • Chronic obstructive pulmonary disease (COPD)

Air pollution can potentially worsen:

  • Cough
  • Breathlessness
  • Chest tightness
  • Wheeze
  • Mucus production
  • General irritation of the airways

It can also make it harder to work out what is causing symptoms. A flare in symptoms is not always due to infection. Sometimes symptoms may be made worse by air pollution, airway irritation, or inflammation, even when there is no new infection.

Dust storms, haze and extreme events

In some parts of the world, especially in North Africa and the Middle East, very high AQI readings are often caused by dust and sand in the air. This can sometimes be mistaken for fog.

Clues that this may be dust rather than fog include:

  • Very high AQI readings
  • Dry-looking haze rather than damp mist
  • Dust collecting on surfaces
  • Weather reports mentioning dust, sand, or reduced visibility

Dust does not always have a noticeable smell, so the absence of smell does not mean the air is safe.

How much protection does staying indoors give?

Staying indoors usually does help, but the amount of protection varies.

Typical home with windows closed

In general terms, staying indoors with windows closed may reduce exposure by around 30% to 70%, depending on:

  • How well sealed the building is
  • Whether windows or doors are being opened
  • The age and condition of the property
  • How long the pollution event lasts

Indoors with HEPA filtration

Using a correctly sized High Efficiency Particulate Air (HEPA) purifier can improve indoor air further. In some situations, this may reduce indoor particle exposure by around 50% to 90% or more.

Important limits

  • Fine particles can still get indoors
  • Older or drafty buildings may offer less protection
  • Opening windows can quickly increase indoor particle levels again

The realistic goal is usually to reduce exposure as much as possible, not to expect complete protection.

Practical ways to reduce exposure

When outdoor AQI is high, the following steps may help:

  • Stay indoors as much as possible
  • Keep windows and doors closed
  • Avoid strenuous outdoor activity
  • Use air filtration if you have it
  • Delay non-essential trips outdoors if practical
  • Check AQI more than once per day during unstable conditions

For some people, symptoms may still occur even indoors. If so, it may help to reduce physical activity, keep rescue medication available if prescribed, and monitor symptoms closely.

Masks and air filtration

Masks

Well-fitted particle-filtering masks such as FFP2 or FFP3 may reduce exposure to fine particles when you need to go outdoors. Their usefulness depends heavily on fit, comfort, and wearing them correctly.

Not everyone can tolerate masks easily, especially if they are already short of breath, so they are not always a complete solution.

Air purifiers

A HEPA purifier may be especially useful in the room where you spend the most time, such as a bedroom or living room. Performance depends on:

  • Correct room size
  • Good maintenance of filters
  • Keeping windows closed during high pollution periods

Buying an air purifier: what matters and what does not

Air purifiers can help reduce indoor particle levels, but it is important to be realistic about what they can and cannot do.

Important: An air purifier does not treat aspergillosis, does not cure asthma or bronchiectasis, and does not remove all particles. It is best thought of as one way to reduce exposure.

What matters most

  • True HEPA filtration (or a clearly specified high-efficiency particle filter)
  • Room-size coverage that matches the room where it will be used
  • Clean Air Delivery Rate (CADR), where provided
  • Noise level, especially if used in a bedroom
  • Replacement filter cost and availability

What these terms mean

True HEPA: This usually means the purifier is designed to remove very small airborne particles efficiently. For patients concerned about dust and polluted air, this is generally more important than extra “smart” features.

Room size: A purifier that is too small for the room may not make much difference. It is usually better to buy the correct size for the room where you spend the most time than to buy a very cheap device that cannot handle the space.

CADR: This is a measure of how quickly a purifier can clean the air. Higher CADR usually means faster particle removal, though room size and real-life use still matter.

What to be cautious about

  • Very cheap devices with vague claims but no clear filter specification
  • Small USB-powered “desk purifiers” claiming to clean large rooms
  • Ioniser-only devices with no proper particulate filter
  • Products that make sweeping medical claims

Practical buying advice

  • Start with the room you use most, often the bedroom or living room
  • Choose a purifier that is rated for that room size
  • Check how often filters need replacing and how much replacements cost
  • Read the real specifications, not just the marketing headline
  • If you are noise-sensitive, look at the sleep-mode or low-speed sound level

Reasonable expectations

Used properly, a good air purifier may make a meaningful difference during high pollution periods, especially when combined with keeping windows closed. However, it is only one part of managing exposure.

Travel and changing environments

Air quality can change dramatically between regions and countries. Some places have persistent urban pollution, while others may experience sudden dust events, wildfire smoke, or seasonal changes.

If you are travelling, it may help to:

  • Check local AQI before travel and during your stay
  • Be aware of seasonal dust or wildfire risks
  • Know where you can spend time indoors if air quality worsens
  • Keep regular medications with you

This can be particularly important if you already know that poor air quality tends to worsen your symptoms.

Common misconceptions

Myth: “If I cannot see pollution, it is safe.”

Fact: Invisible pollution such as PM2.5 and gases can still be harmful.

Myth: “If the air looks foggy, it must just be water vapour.”

Fact: Hazy air can sometimes be caused by dust or pollution rather than fog.

Myth: “Staying indoors completely solves the problem.”

Fact: Staying indoors usually reduces exposure, but does not remove it completely.

Myth: “If my symptoms worsen, it must be an infection.”

Fact: Pollution and airway irritation can also worsen symptoms.

Myth: “Air pollution is always caused by traffic.”

Fact: Pollution may come from natural, industrial, and domestic sources, often in combination.

Managing your condition during high air pollution

For people with aspergillosis, asthma, bronchiectasis or other lung conditions, air pollution can trigger symptoms even when there is no infection. Having a simple plan can help you feel more in control.

Continue your regular medication

  • Take your prescribed medications as usual, including inhalers or antifungal treatments
  • Do not stop or reduce medication without medical advice

Have your reliever medication available

  • Carry your reliever inhaler (if prescribed) when leaving the house
  • Make sure it is within easy reach, not packed away
  • Check that it is in date and not empty

Plan ahead before going outdoors

  • Check the AQI before leaving home
  • Avoid going out during peak pollution times if possible
  • Consider shorter trips or lower-exertion activities

Adjust activity levels

  • Reduce strenuous activity when AQI is high
  • Walk more slowly and allow extra time
  • Take breaks if you feel breathless

Know your early warning signs

Be aware of symptoms that may indicate your lungs are being affected:

  • Increased breathlessness
  • More coughing or wheezing
  • Chest tightness
  • Unusual fatigue

Have a simple action plan

  • Know what you usually do if symptoms worsen
  • Follow any personalised plan provided by your clinical team
  • Seek advice if symptoms are different from your usual pattern

Practical tip: On high pollution days, think ahead before leaving home—take medication with you, plan shorter trips, and allow extra time so you do not have to rush.

When to seek medical help

Seek medical advice promptly if you notice:

  • Worsening breathlessness
  • New or worsening wheeze
  • Chest tightness that is not settling
  • A major increase in cough
  • Coughing blood (haemoptysis)
  • Symptoms that are more severe than your usual pattern

If you have a severe flare, marked breathing difficulty, or significant haemoptysis, seek urgent medical help.

Final takeaway

Outdoor air pollution is an important and often under-recognised trigger for people with lung disease. For patients with aspergillosis and related lung conditions, it can worsen symptoms even when there is no new infection.

The most helpful practical points are:

  • Use AQI rather than appearance alone
  • Remember that pollution may be visible or invisible
  • Stay indoors when AQI is high
  • Use air filtration where possible
  • Keep an eye on changing symptoms and seek help if needed

References

Author: Prepared for aspergillosis.org

Review note: This article is intended for general education and should not replace advice from your own clinical team.

by GAtherton

Damp & Mould Health Evidence Monitor: 4 March 2026

Date of check

4 March 2026

🆕 New papers since last check

Early-life indoor mould exposure and lung function

Journal: Environmental Research: Health
Published: Feb 2026

Summary
Children exposed to serious indoor mould in early life showed:

  • reduced lung function in adolescence

  • increased risk of asthma during childhood

This study used long-term cohort data and objective lung function testing, strengthening the evidence that early mould exposure can have lasting respiratory consequences.

PMID: 39162373
PubMed link:
https://pubmed.ncbi.nlm.nih.gov/39162373/

Damp and mouldy homes: impact on lung health in childhood

Authors: Moorcroft C, Whitehouse A, Grigg J
Journal: Archives of Disease in Childhood (2025)

Summary
This clinical review explains how damp housing contributes to:

  • childhood asthma

  • recurrent respiratory infections

  • allergic disease

It emphasises that paediatric clinicians frequently encounter children whose symptoms are linked to poor housing conditions.

PMID: 39814530
PubMed link:
https://pubmed.ncbi.nlm.nih.gov/39814530/

Damp housing and mental health effects

Journal: Environmental Health Perspectives

Summary
A major review examining whether damp and mould exposure affects mental health.
Evidence suggests associations with:

  • anxiety

  • depression

  • psychological stress

Mechanisms may include chronic illness, housing insecurity, and inflammatory responses to mould exposure.

PMID: 39162373
PubMed link:
https://pubmed.ncbi.nlm.nih.gov/39162373/

📊 Summary

New or important items identified

• Evidence continues to strengthen the link between damp housing and respiratory disease
• Long-term cohort data show effects on lung development
• Emerging research also suggests mental health impacts

by GAtherton

Health effects: why aspergillosis patients are higher-risk

Home › Knowledge Hub › Damp, mould and aspergillosis › Health effects

This page explains what damp and mould can do to the lungs and how to recognise patterns that suggest your home is contributing to symptoms.

How damp buildings can affect the lungs

Damp homes can increase exposure to airborne particles including fungal spores and fragments. For many people this causes irritation; for people with chronic lung disease it can trigger significant exacerbations.

  • Worsening cough, wheeze, breathlessness
  • Increased mucus and reduced airway clearance
  • More frequent chest infections / antibiotic courses
  • Allergic-type reactions in sensitised individuals

Why aspergillosis and severe airways disease are different

If you have Aspergillus-related disease or severe asthma/bronchiectasis, your airways may react strongly to fungal material and irritants. Some patients also require systemic or inhaled corticosteroids, which can increase susceptibility to infections and complicate symptom control.

Important nuance: a damp home does not automatically “cause” aspergillosis, but it can be a powerful driver of persistent symptoms and repeated flares.

Patterns that support a housing contribution

  • Time-and-place pattern: symptoms worsen at home and improve when away (even partially).
  • Multi-person effects: more than one household member develops respiratory/allergic symptoms.
  • Post-disturbance worsening: symptoms worsen after “repairs” or “remediation”.
  • Escalating medication use: increased reliever inhaler/nebuliser use, repeated steroid bursts, more antibiotics.

Simple symptom timeline template (copy/paste)

Keeping a short, factual timeline helps clinicians and councils understand risk.

Date(s):
Where damp/mould is present:
What changed (rain event, leak, repair work, return after decant):
Symptoms (breathlessness/wheeze/cough/fever/skin/eyes/nose):
Medication change (inhalers, steroids, antibiotics):
Healthcare use (GP/A&E/hospital):
Improves when away from home? (yes/no, how quickly):

What to ask your clinician to document

  • Diagnosis (e.g., Chronic pulmonary aspergillosis, allergic bronchopulmonary aspergillosis, asthma, bronchiectasis)
  • That symptoms are consistent with environmental triggers or worsened by damp/mould exposure (they do not need to prove causation)
  • Any vulnerability factors (steroid use, immunosuppression, reduced lung function)

by GAtherton

Damp, mould and aspergillosis in rented homes (UK)

Home › Knowledge Hub › Damp, mould and aspergillosis (UK rented homes)

A comprehensive guide for patients and carers. If you rent your home and worry that damp or mould may be worsening symptoms, these pages explain how to recognise risk, what to do next, and how to escalate safely.

Who this guide is for

  • People living with Chronic pulmonary aspergillosis and other long-term lung disease.
  • People living with Allergic bronchopulmonary aspergillosis or Severe asthma with fungal sensitisation.
  • Carers, family members, and support workers.
  • Clinicians and housing professionals seeking a patient-centred overview.

The key message

A damp home does not automatically cause aspergillosis. However, damp and mould can:

  • worsen airway inflammation and symptoms
  • trigger exacerbations in asthma/bronchiectasis
  • increase allergic-type reactions in sensitised people
  • make it harder to stabilise symptoms even with optimal treatment

This hub focuses on practical steps: recognising risk early, communicating effectively, understanding remediation quality, and using UK escalation routes.

How to use this hub

  1. Start with Recognising a damp home to build an evidence base.
  2. Read Health effects to understand patterns that support an environmental contribution.
  3. Use Landlord communications to push for a safe plan, not cosmetic fixes.
  4. Check Remediation & refusal to move if you’re being pressured to return.
  5. Use Law & support for UK rights and escalation routes.

Important safety note

If you have severe breathlessness, chest tightness, wheeze, or features of anaphylaxis (for example lip/tongue swelling, throat tightness, collapse), seek urgent medical help. If you are repeatedly attending A&E with symptoms that seem worse at home, tell clinicians you are concerned about damp/mould exposure.

by GAtherton

Recognising a damp or mouldy home

Home › Knowledge Hub › Damp, mould and aspergillosis › Recognising a damp home

Many high-risk exposures occur before mould is obvious. This page helps you identify early signs and start documenting evidence.

Early warning signs (often missed)

  • Condensation on windows most mornings
  • Cold, clammy walls or cupboards; wardrobes that feel “damp”
  • Persistent musty odour (especially when returning home)
  • Peeling wallpaper, bubbling paint, cracking plaster
  • Recurring black staining on silicone/grout
  • Swollen skirting boards, warped flooring, rusting fittings

High-risk hidden locations

  • Behind wardrobes/sofas on external walls
  • Inside cupboards on outside walls
  • Under sinks, behind washing machines, around toilets/baths
  • Window reveals, behind curtains/blinds
  • Loft hatches and boxed-in pipework

Common causes (useful when speaking to landlords)

  • Water ingress (doors/windows, defective seals, roof, gutters, downpipes)
  • Plumbing leaks (slow leaks behind walls or under floors)
  • Ventilation failures (broken/weak extract fans, blocked vents)
  • Cold bridging and persistent condensation in poorly insulated areas
  • Previous flooding/leaks with inadequate drying

Quick evidence checklist (10 minutes)

  1. Take dated photos of any mould, staining, peeling paint, wet patches.
  2. Photograph likely sources: door thresholds, window seals, gutters if visible, extractor fans, vents.
  3. Write down where the smell is strongest and when it’s worst (after rain, in winter, after showers).
  4. Start a brief symptom note (see Page 3) and keep everything in one folder.
  5. Report the issue in writing to your landlord/agent and keep screenshots/confirmation.

What not to do (for safety)

  • Do not scrape or disturb mouldy plasterboard or insulation yourself.
  • Do not rely on bleach-only cleaning as a “solution” (it may not address underlying moisture or embedded contamination).
  • Do not accept repeated “paint over and close the ticket” approaches without a cause-and-fix plan.

by GAtherton