Infographic showing a space-resistant Aspergillus fungus near the International Space Station alongside lungs affected by aspergillosis, illustrating how fungal survival research in space may improve understanding of human fungal disease.

What a Space-Resistant Fungus Can Teach Us About Aspergillosis

A recent Smithsonian article described how a microscopic fungus survived conditions designed to sterilise spacecraft. At first glance, this might sound like a story about space exploration rather than human health. But for people living with aspergillosis, it carries an important and surprisingly positive message.

Fungi are remarkable survivors

The article describes research showing that some Aspergillus spores can survive extreme conditions, including harsh radiation, dryness and cleaning procedures. This does not mean that aspergillosis patients need to worry about “space fungi”. Instead, it highlights something patients and specialists already understand very well: fungi are extraordinarily resilient organisms.

Aspergillus spores are common in the environment. They can be found in soil, compost, decaying leaves, dust, damp buildings and sometimes even very clean environments. Most people breathe in small numbers of spores every day without becoming ill, because their lungs and immune system clear them effectively.

For people with lung disease, asthma, immune system problems or damaged lung tissue, however, Aspergillus can sometimes cause illness. This includes conditions such as chronic pulmonary aspergillosis, allergic bronchopulmonary aspergillosis and severe asthma with fungal sensitisation.

A positive message for patients

One positive message from this research is that aspergillosis is not caused by weakness, poor hygiene or personal failure. Fungi are genuinely formidable organisms. If some fungal spores can survive environments as extreme as those used in space research, it becomes easier to understand why completely avoiding Aspergillus in everyday life is difficult.

This can be reassuring for patients who feel frustrated when symptoms persist despite doing “everything right”. It is not that they are failing. It is that fungal biology is complex, and fungal exposure is part of the natural world.

Why this matters emotionally

Many people with aspergillosis say they feel misunderstood. They may hear comments such as:

“It’s only mould.”
“Surely it should have cleared by now.”
“Why are you still worrying about it?”

Stories like this help show that fungi are not simple or trivial. They are ancient, adaptable and scientifically fascinating organisms. Aspergillosis is therefore not “just mould exposure”; it is a real medical condition involving a complex interaction between the fungus, the lungs and the immune system.

Science is taking fungi more seriously

Another encouraging message is that fungi are attracting more scientific attention. Researchers are studying fungal survival, environmental spread, resistance to treatment, and the ways fungi interact with humans and indoor environments.

This matters because better understanding can lead to better diagnosis, better treatment and better prevention. In recent years, fungal medicine has already benefited from improvements in CT scanning, fungal blood tests, respiratory samples, antifungal treatments and biologic medicines for some allergic forms of disease.

Resilience goes both ways

The story also offers a useful reflection: fungi are resilient, but so are patients.

Many people living with aspergillosis adapt to long-term symptoms, hospital appointments, uncertainty, fatigue and treatment decisions. They continue to work, care for families, attend support groups, learn about their condition and help others understand fungal disease.

That resilience deserves recognition.

What patients can take from this

Aspergillus is difficult to avoid completely, so exposure reduction should be realistic rather than perfectionist.
Persistent symptoms are not a personal failure; fungal diseases can be complex and long-lasting.
Fungal science is advancing, and aspergillosis is increasingly recognised as an important medical condition.
Patients’ experiences are valid, even when others do not fully understand them.

When to seek medical advice

People with aspergillosis or suspected aspergillosis should seek medical advice if they develop worsening breathlessness, coughing up blood, unexplained weight loss, persistent fever, chest pain, a major change in sputum, or a significant deterioration in day-to-day symptoms.

Anyone already under specialist care should follow their agreed care plan and contact their clinical team if symptoms change significantly.

Key points

Dampness and mould can matter for people with respiratory disease.
The most important question is usually: why is moisture present?
Air sampling and mould spore counts have major limitations and should not be relied on alone.
A “normal” air test does not reliably prove that a home is free from damp or hidden mould.
The best assessments usually focus on building defects, condensation, ventilation, leaks and moisture sources.
For complex problems, experienced chartered building professionals and occupational/environmental hygienists are often more useful than simple “mould testing” services.
Dust and dirt accumulation may contribute to mould growth and respiratory irritation, especially in damp environments.
Recent UK housing guidance increasingly recognises the health impact of damp and mould.

Why damp and mould matter

Fungi are a normal part of the environment. Tiny fungal spores are present in outdoor air, soil, gardens, compost and many indoor spaces. Most people breathe in small numbers of spores every day without becoming ill.

However, persistent dampness indoors can allow mould growth to increase. This may worsen irritation, allergy, asthma symptoms or respiratory symptoms in some people.

People who may be more sensitive include those with:

Allergic Bronchopulmonary Aspergillosis (ABPA)
Chronic Pulmonary Aspergillosis (CPA)
Severe Asthma with Fungal Sensitisation (SAFS)
bronchiectasis
Chronic Obstructive Pulmonary Disease (COPD)
cystic fibrosis
severe asthma
significant allergies
or a weakened immune system.

Signs your home may have a damp problem

Visible signs

black, green or white mould growth
condensation on windows
damp patches
peeling wallpaper or paint
bubbling plaster
staining on walls or ceilings
warped wood
persistent condensation

Smell

A persistent musty, earthy or “damp” smell can sometimes indicate hidden moisture or mould growth, even when little is visible.

Possible building causes

leaks from roofs, gutters or plumbing
poor ventilation
condensation
cold external walls
thermal bridging
rising damp
penetrating damp
blocked air vents
drying clothes indoors without enough ventilation.

Can dust and dirt make mould problems worse?

Yes. Accumulated dust and dirt can sometimes contribute to indoor mould problems, especially when combined with moisture or high humidity.

Dust is not simply “dirt” — it often contains:

skin cells
textile fibres
pollen
bacteria
fungal spores
organic material
and microscopic debris.

When dust accumulates in damp or poorly ventilated areas, it can provide nutrients that allow mould growth to establish more easily on surfaces.

This is particularly common:

behind furniture placed against cold walls
around windows
on curtains and blinds
inside wardrobes
under beds
around ventilation grilles
and in areas with condensation.

For people with asthma, allergy or aspergillosis, heavy dust accumulation may also worsen irritation or respiratory symptoms independently of visible mould.

Symptoms that may be triggered or worsened

Damp or mould exposure may contribute to:

coughing
wheezing
chest tightness
breathlessness
increased sputum
nasal irritation
sinus symptoms
eye irritation
fatigue
worsening asthma control
increased allergy symptoms.

Symptoms may be more noticeable in certain rooms, overnight, during winter, after rainfall, or when ventilation is poor.

However, symptoms alone cannot prove that mould exposure is the cause. Many respiratory conditions can cause similar symptoms, so medical advice is important if symptoms are worsening.

Should you get air testing done?

Many companies offer indoor air sampling, mould spore counts or fungal testing. Patients often hope this will provide reassurance or proof that a home is safe.

Unfortunately, air sampling has important limitations.

Limitations of air sampling

There are no universally agreed “safe” mould spore levels for homes.
Results can vary enormously throughout the day.
Outdoor air can strongly influence indoor results.
Cleaning, vacuuming, opening windows or walking around can alter results.
A short air sample may not represent usual exposure.
Hidden damp or mould may not show up in an air sample.
A “normal” air test does not reliably prove that a building is free from damp or mould problems.

Air sampling may sometimes be useful when carried out by experienced specialists as part of a wider investigation. However, it should not be used as the only basis for deciding whether a home is safe or whether remediation has worked.

What usually matters most?

The key question is usually:

Why is moisture present in the home?

Without moisture, significant mould growth usually cannot continue. Therefore, the most important step is to identify and correct the source of dampness.

This may involve:

repairing leaks
improving ventilation
reducing condensation
correcting insulation or thermal bridging problems
repairing gutters, roofs or plumbing
addressing overcrowding or excessive indoor humidity.

What you can do yourself

Improve ventilation

Use extractor fans in bathrooms and kitchens.
Open windows when practical and safe.
Do not block air vents.
Ventilate after showering, cooking or drying clothes.

Reduce indoor humidity

Dry clothes outdoors where possible.
Use lids on pans while cooking.
Avoid drying clothes on radiators without ventilation.
Consider a humidity monitor.
Aim to avoid persistently high indoor humidity.

A dehumidifier may help reduce humidity in some situations, but it does not fix the underlying cause of dampness if there is a leak, structural defect or ventilation problem.

Reduce dust accumulation

Clean regularly using methods that minimise dust disturbance.
Pay particular attention to hidden or poorly ventilated areas.
Move furniture slightly away from cold external walls where possible.
Reduce clutter that traps dust and moisture.
Wash soft furnishings and curtains regularly if practical.

Clean small areas carefully

Small areas of surface mould can sometimes be cleaned carefully using appropriate cleaning products. Avoid dry brushing or actions that disturb mould and release spores into the air.

People with significant lung disease, severe asthma, severe allergy or aspergillosis may prefer somebody else to carry out cleaning to reduce exposure.

Large, recurring or hidden mould problems usually need professional assessment.

Who is most likely to provide reliable help?

The most useful professionals are usually those who investigate the building and the source of moisture, not just the air.

For complex damp or mould problems, more robust help may come from:

experienced chartered building surveyors
building pathology specialists
chartered building engineers
occupational hygienists
environmental hygienists with experience in indoor air quality and moisture assessment.

Relevant UK professional bodies

Some damp and remediation companies may also be associated with the Property Care Association (PCA). This may indicate relevant industry training, but membership alone does not guarantee expertise. Experience and independence still matter.

Is impartial advice available?

Sometimes. People are often unsure where to obtain trustworthy, independent advice about damp and mould.

Possible sources of impartial guidance may include:

local council Environmental Health departments
housing officers (for tenants)
Citizens Advice services
NHS guidance
UK Health Security Agency (UKHSA) guidance
recognised professional bodies.

Local councils may sometimes inspect severe housing conditions, particularly where:

children or vulnerable adults are involved
landlords are failing to act
there is extensive visible mould
or housing conditions may present health hazards.

Support varies considerably between areas, and services are often stretched, but councils can sometimes require landlords to take action where housing conditions are unsafe.

Awaab’s Law and what it may mean for tenants

For people living in rented accommodation, especially social housing, recent changes in UK housing law may provide stronger protection where damp and mould problems are affecting health.

Awaab’s Law was introduced following the death of two-year-old Awaab Ishak in Rochdale after prolonged exposure to severe mould in social housing.

The law strengthens expectations that social landlords:

investigate damp and mould complaints promptly
assess potential risks to health
carry out repairs within defined timescales
and respond more urgently where vulnerable people are involved.

This is particularly important for people with:

aspergillosis
asthma
bronchiectasis
Chronic Obstructive Pulmonary Disease (COPD)
cystic fibrosis
or weakened immune systems.

What tenants should do

If you are concerned about damp or mould in rented accommodation, it may help to:

report problems formally and in writing where possible
keep photographs and dates
record repeated complaints
document worsening conditions
keep copies of correspondence
retain relevant medical letters if symptoms are worsening.

Where severe respiratory disease is present, medical evidence may help demonstrate vulnerability and the need for urgent action.

Important limitations

Awaab’s Law does not mean that every mould problem becomes an emergency or that all homes can be repaired immediately. Housing shortages, structural problems, funding limitations and contractor delays still affect what can be achieved.

However, the law has strengthened the expectation that damp and mould complaints should be taken seriously and addressed promptly, particularly where vulnerable people are affected.

NICE guidance and UK guidance

The National Institute for Health and Care Excellence (NICE) has increasingly recognised the importance of indoor air quality and housing conditions in respiratory health.

In addition, the UK Health Security Agency (UKHSA) has published major guidance emphasising that:

damp and mould should be addressed promptly
visible mould should not be ignored
people with respiratory disease may be more vulnerable
and simply blaming lifestyle alone is often inappropriate.

Recent UK guidance has increasingly shifted away from treating damp and mould purely as cosmetic issues, recognising their potential health impacts — especially for vulnerable people.

Questions to ask before paying for an assessment

What qualifications and experience do you have in damp, mould and building moisture problems?
Are you independent, or do you also sell remediation work?
Will you investigate moisture sources, ventilation and building defects?
Will I receive a written report explaining the likely cause?
How will you decide whether remediation has worked?
Will you explain the limitations of any air sampling?
Do you use air sampling as part of a wider assessment, or as the main test?

Be cautious if...

the assessment mainly consists of a quick air sample
dramatic health claims are made
the report presents spore counts as a simple “safe/unsafe” result
expensive remediation is recommended immediately
the company creates pressure to buy treatment packages
there is little attention to leaks, condensation, ventilation or building defects.

How do you know remediation has worked?

Success should usually be judged by practical outcomes, including:

visible mould has been removed safely
the source of moisture has been corrected
damp patches are drying out
musty smells have reduced
ventilation has improved
humidity is better controlled
mould does not quickly return
symptoms improve over time, where mould exposure was contributing.

Repeat air sampling alone is not a reliable way to prove that a home is safe.

When to seek medical advice

People with aspergillosis or other lung conditions should seek medical advice if they experience:

worsening breathlessness
coughing blood
rapidly worsening asthma symptoms
fever or signs of infection
unexplained weight loss
significant deterioration in chest symptoms
new or worsening fatigue with chest symptoms.

If symptoms appear linked to a damp or mouldy environment, discuss this with your healthcare team. They may not be able to assess the building, but they can help assess your health and whether your respiratory condition is changing.

Promotional poster for a UK citizen science project exploring damp homes, mould exposure and respiratory health including aspergillosis — Citizen science project exploring how damp homes, mould exposure and housing conditions may affect respiratory health, including aspergillosis, asthma and COPD.

Related information on Aspergillosis.org

Useful resources

by GAtherton

Infographic showing how to reduce Aspergillus mould exposure at home including ventilation, humidity control, cleaning, and common sources like damp, compost, and houseplants

Reducing Exposure to Mould (Aspergillus) at Home

Last reviewed: May 2026
Audience: Patients with aspergillosis (including Allergic Bronchopulmonary Aspergillosis and Chronic Pulmonary Aspergillosis), carers, and non-specialist cliniciansIf you have aspergillosis, reducing exposure to environmental moulds such as Aspergillus can help minimise symptoms and reduce the risk of flare-ups.This guide brings together practical, evidence-informed advice based on environmental studies and clinical experience at specialist centres such as the National Aspergillosis Centre (Manchester, UK).

🔑 Key Points

Aspergillus spores are present in the air almost everywhere.
Complete avoidance is not possible—focus on reducing higher-level exposures.
The most important drivers are moisture, organic decay, and disturbance.
Indoor exposure is often more important than outdoor exposure.
Simple environmental and behavioural changes can significantly reduce risk.

🌍 Where does mould exposure come from?

Aspergillus is a common environmental mould. It grows on organic material and releases microscopic spores into the air.

Common sources include:

Damp walls, ceilings, and condensation
Soil, compost, and plant material
Dust and poorly ventilated spaces
Food waste and decaying organic matter

Spores are always present at low levels. Problems arise when concentrations increase, particularly in enclosed or damp environments.

⚖️ Who is most affected?

Reducing exposure is particularly relevant for people with:

Allergic Bronchopulmonary Aspergillosis (ABPA)
Chronic Pulmonary Aspergillosis (CPA)
Asthma or bronchiectasis
Reduced immune function

Individual sensitivity varies. Some people notice clear environmental triggers, while others are less affected by day-to-day variation.

⚠️ What symptoms can mould exposure trigger?

Exposure may trigger or worsen symptoms by increasing airway inflammation or allergic responses.

Respiratory symptoms

Increased breathlessness
Wheezing or chest tightness
Persistent or worsening cough
Increased or thicker mucus
Reduced peak flow (if monitored)

Allergic-type symptoms

Nasal congestion or runny nose
Itchy throat
Sneezing

General symptoms

Fatigue
Reduced exercise tolerance

In ABPA, exposure may contribute to flare-ups. In CPA, changes may be more gradual.

👀 What should you watch out for?

Patterns are often more informative than single exposures.

Symptoms worsening after specific activities (e.g. gardening, cleaning)
Symptoms linked to particular rooms or buildings
Improvement when away from home
Worsening in damp or musty environments

Keeping a simple symptom diary can sometimes help identify triggers.

Important: Not all symptoms are due to mould exposure—other factors such as infection or asthma control may also play a role.

🏠 Reducing mould in your home

1. Control moisture (most important factor)

Fix leaks promptly (pipes, roofs, windows)
Dry condensation from windows and walls
Avoid prolonged indoor drying of clothes where possible

Moisture is the key driver of mould growth—reducing it addresses the root cause.

2. Improve ventilation

Open windows regularly (even short periods can help)
Use extractor fans in kitchens and bathrooms
Avoid blocking vents or airflow pathways

Ventilation removes spores and reduces humidity at the same time.

3. Manage condensation

Maintain a relatively stable indoor temperature
Use lids when cooking
Consider dehumidifiers in problem areas

🌬️ Ventilation, filtration and humidity

Ventilation (first priority)

Ventilation is usually the most effective intervention because it removes airborne spores and reduces moisture.

Dehumidifiers

Dehumidifiers reduce indoor humidity (target around 40–60%), making conditions less favourable for mould growth.

HEPA air purifiers

HEPA filters can remove airborne particles, including fungal spores. However, they do not address the source of mould and are best used alongside other measures.

Practical approach: address moisture and ventilation first, then consider additional filtration if needed.

🌦️ Does weather affect mould exposure?

Rain can reduce airborne spores by washing them out of the air
Cold conditions reduce fungal growth
Dry, windy weather can increase exposure by disturbing dust and soil

However, indoor conditions usually have a greater impact than outdoor weather.

🌍 Do some environments reduce exposure?

Some environments may be associated with lower exposure:

Dry climates (lower humidity)
Coastal areas (good airflow and dilution)
Cooler conditions (reduced fungal growth)

There is no completely “safe” location, and indoor conditions often matter more than geography.

🌿 Activities and exposure

Some activities can temporarily increase exposure:

Gardening or handling compost
Cleaning dusty areas
Handling stored materials

Precautions:

Wear a well-fitted mask (FFP2 or FFP3)
Carry out dusty tasks outdoors where possible
Avoid enclosed, poorly ventilated spaces

🗑️ Indoor compost bins and food waste

Food waste provides an ideal environment for mould growth.

Risk increases when waste is stored indoors for prolonged periods, particularly in warm conditions.

Empty bins frequently (ideally daily)
Use sealed containers
Keep in well-ventilated areas
Clean bins regularly

🌱 Houseplants

The main risk comes from soil and moisture rather than the plant itself.

👉 Read full guide on houseplants and aspergillosis

⚖️ Balancing risk and quality of life

It is important to balance exposure reduction with maintaining normal daily activities.

Gardening can often continue with precautions
Houseplants can often be kept safely
Focus on reducing higher-risk exposures rather than avoiding everything

⚠️ When to seek medical advice

Increasing breathlessness
Worsening cough or mucus
Reduced peak flow
Symptoms clearly linked to environment

Seek urgent advice for:

Rapid breathlessness
Chest pain
Coughing blood

📚 Further reading

👩‍⚕️ Author & Review

Developed using patient questions and reviewed in line with National Aspergillosis Centre practice (Manchester, UK).
This information is general and does not replace individual medical advice.

by GAtherton

Houseplants and aspergillosis risk showing how soil and moisture can expose people with ABPA to Aspergillus spores and how to reduce risk

Houseplants and Aspergillosis: Do You Need to Get Rid of Them?

Last reviewed: May 2026
Audience: Patients with aspergillosis (including Allergic Bronchopulmonary Aspergillosis), carers, and non-specialist cliniciansHouseplants are a common concern for people with
aspergillosis, particularly those with
Allergic Bronchopulmonary Aspergillosis (ABPA).If you’ve asked this question, you’re not alone—many patients raise it in our
patient questions and discussions.

🔑 Key Points

Houseplants can be a source of Aspergillus spores, mainly from soil.
Most people with ABPA do not need to remove all plants.
The main risk comes from damp soil and disturbance.
Simple precautions can significantly reduce exposure.
How plants are cared for matters more than the type of plant.

Why houseplants can be a problem
How big is the risk?
Do houseplants clean the air?
Can I safely keep my plants?
How to reduce risk
Are some plants lower risk?
When to consider removing plants
Common questions
When to seek medical advice
References

🌱 Why can houseplants be a problem?

Aspergillus is a common environmental mould found in:

Soil and compost
Decaying plant material
Damp indoor environments

For people with Allergic Bronchopulmonary Aspergillosis (ABPA), inhaling spores can trigger airway inflammation, wheeze, cough, and breathlessness.

The main risk comes from soil rather than the plant itself.

⚖️ How big is the risk?

The risk varies depending on:

How stable your condition is
The number of plants
Ventilation in your home
How plants are maintained

Specialist centres such as the National Aspergillosis Centre (NAC) recommend a
risk reduction approach rather than complete avoidance.
You can read more in our guide to
reducing mould exposure.

Important: There is limited direct research linking houseplants to worsening ABPA. Advice is based on environmental studies and clinical experience.

🌿 Do houseplants clean the air?

You may have heard that houseplants “clean the air.” This idea comes from laboratory studies, including research by
:contentReference[oaicite:0]{index=0}, conducted in sealed environments.

In real homes, the effect is minimal.

Very large numbers of plants would be needed
Ventilation has a much greater impact
Soil may introduce Aspergillus spores

For a broader explanation, see our
aspergillosis overview.

Bottom line: Plants may improve wellbeing, but they are not an effective air-cleaning strategy.

🌿 Can I safely keep my houseplants?

In many cases, yes.

Many people with ABPA keep houseplants without problems when their condition is stable and plants are well maintained.

However, some individuals are more sensitive, so a personalised approach is important.

✅ How to reduce your risk

1. Manage the soil carefully

Avoid constantly damp compost
Allow the top layer to dry between watering
Consider lower-organic substrates (e.g. clay pebbles)

Tip from patients: Adding a layer of stones or gravel on top of the soil can reduce disturbance during watering and may help limit release of fungal spores.

2. Avoid disturbing soil indoors

Repot plants outside if possible
Wear a well-fitted mask (FFP2 or FFP3)

3. Maintain good plant hygiene

Remove dead leaves promptly
Avoid visible mould growth
Do not allow stagnant water

4. Choose locations carefully

Keep plants out of bedrooms
Ensure good ventilation

5. Personal hygiene after handling plants

Wash hands after handling soil or compost
Avoid touching your face before cleaning hands
Consider changing clothes after heavy gardening
Ventilate the area after indoor plant work

These steps form part of a wider approach to
reducing environmental exposure.

🌿 Are some plants lower risk for ABPA?

There is no strong evidence that specific plants are “safe” or “unsafe.” The main risk comes from soil and moisture.

Some setups may be lower risk in practice:

Hydroponic or semi-hydroponic plants
Plants that prefer drier conditions (e.g. succulents)
Well-maintained plants with minimal decaying material

Important: Any plant can become higher risk if soil becomes damp or mouldy.

If unsure, you may wish to review
clinical guidance or discuss with your care team.

🚩 When should I consider removing plants?

Symptoms worsen after watering or handling plants
Visible mould in soil
Frequent flare-ups
Clinical advice recommends stricter avoidance

Some people remove plants temporarily during unstable periods and reintroduce them later.

❓ Common questions

Are leaves dangerous?

No—the main risk comes from soil and decaying material.

Is outdoor gardening riskier?

Yes, due to higher exposure. Wearing a mask is recommended.

Do air purifiers help?

HEPA filters may reduce airborne particles, but evidence specific to ABPA is limited.

⚠️ When to seek medical advice

Increasing breathlessness or wheeze
Worsening cough or mucus
Reduced peak flow
Symptoms linked to specific environments

Do not change treatment without medical advice.

📚 References & Further Reading

What is aspergillosis?
Reducing exposure to mould
World Health Organization – Indoor air quality guidance
UK Health Security Agency – Damp and mould health risks

👩‍⚕️ Author & Review

Developed for patient education in line with UK specialist practice (National Aspergillosis Centre, Manchester).
This information is general and does not replace individual medical advice.

Looking for more answers? Visit our
patient questions hub.

by GAtherton

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

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.

Why indoor air matters
What the review found
Damp, mould and lung health
Aspergillus and aspergillosis
Ventilation and building design
What can help reduce risk?
Help us understand damp homes and health
When to seek medical advice

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.

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

Beswick A, Crook B, Gosling B, et al. Exposure Risks from Microbiological Hazards in Buildings and Their Control — A Rapid Review of the Evidence. Atmosphere. 2025;16:1243. doi:10.3390/atmos16111243.
Damp homes and health study — register your interest
Aspergillosis.org — patient and carer information

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.

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

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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.

Why this topic is confusing
Mould exposure vs Aspergillus disease
Mycotoxins and “detox” claims
Why “mould toxin tests” are not used diagnostically
Why symptoms don’t have one single cause
How Aspergillus conditions are actually diagnosed
When home testing may be used
What matters most for patients

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.

What affects indoor air?
Three common problems
Aspergillus in the home
Damp and mould
Symptoms and health effects
Identifying problems
Getting the right help
Practical steps
Air purifiers

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

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.

What is outdoor air pollution?
Where does it come from?
Visible or invisible pollution
Understanding AQI (Air Quality Index)
Where to check AQI
Why air pollution matters in aspergillosis
Dust storms, haze and extreme events
How much protection does staying indoors give?
Practical ways to reduce exposure
Masks and air filtration
Buying an air purifier: what matters and what does not
Travel and changing environments
Common misconceptions
Managing your condition during high air pollution
When to seek medical help
References

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:

QAir AirVisual
– widely used internationally, with real-time air quality data, forecasts, and health guidance
UK Department for Environment, Food & Rural Affairs (DEFRA) – UK-AIR
– official UK air quality data and health advice
Plume Labs
– useful for air-quality maps and forecasts
Windy
– helpful for visualising dust, smoke and weather patterns

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

World Health Organization. WHO Global Air Quality Guidelines. 2021.
UK Department for Environment, Food & Rural Affairs (DEFRA). UK-AIR: Air Information Resource.
IQAir AirVisual air quality app.
European Respiratory Society statements and guidance on air pollution and respiratory health.
British Thoracic Society resources on respiratory health and environmental exposure.

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

Fungi are remarkable survivors

A positive message for patients

Why this matters emotionally

Science is taking fungi more seriously

Resilience goes both ways

What patients can take from this

When to seek medical advice

Further reading

A UK Citizen Science Project

Why this matters

Related information

Find out more or register your interest

Key points

Why damp and mould matter

Signs your home may have a damp problem

Visible signs

Smell

Possible building causes

Can dust and dirt make mould problems worse?

Symptoms that may be triggered or worsened

Should you get air testing done?

Limitations of air sampling

What usually matters most?

What you can do yourself

Improve ventilation

Reduce indoor humidity

Reduce dust accumulation

Clean small areas carefully

Who is most likely to provide reliable help?

Relevant UK professional bodies

Is impartial advice available?

Awaab’s Law and what it may mean for tenants

What tenants should do

Important limitations

NICE guidance and UK guidance

Questions to ask before paying for an assessment

Be cautious if...

How do you know remediation has worked?

When to seek medical advice

Related information on Aspergillosis.org

Useful resources

🔑 Key Points

🌍 Where does mould exposure come from?

⚖️ Who is most affected?

⚠️ What symptoms can mould exposure trigger?

Respiratory symptoms

Allergic-type symptoms

General symptoms

👀 What should you watch out for?

🏠 Reducing mould in your home

1. Control moisture (most important factor)

2. Improve ventilation

3. Manage condensation

🌬️ Ventilation, filtration and humidity

Ventilation (first priority)

Dehumidifiers

HEPA air purifiers

🌦️ Does weather affect mould exposure?

🌍 Do some environments reduce exposure?

🌿 Activities and exposure

🗑️ Indoor compost bins and food waste

🌱 Houseplants

⚖️ Balancing risk and quality of life

⚠️ When to seek medical advice

📚 Further reading

👩‍⚕️ Author & Review

🔑 Key Points

Contents

🌱 Why can houseplants be a problem?

⚖️ How big is the risk?

🌿 Do houseplants clean the air?

🌿 Can I safely keep my houseplants?

✅ How to reduce your risk

1. Manage the soil carefully

2. Avoid disturbing soil indoors

3. Maintain good plant hygiene

4. Choose locations carefully

5. Personal hygiene after handling plants

🌿 Are some plants lower risk for ABPA?

🚩 When should I consider removing plants?