Cleaner air, healthier childhoods: reasons for hope
For anyone living with asthma, the prospect of fewer children developing the condition has real meaning. Less breathlessness, fewer disturbed nights, and less worry for children and their families are benefits we can readily understand.
Changing how we travel and generate electricity involves considerable investment, disruption and political debate. Much of the discussion centres on protecting the climate in decades to come. But cleaner transport and energy also offer opportunities to improve health today.
Research is showing movement in an encouraging direction. Electric vehicle uptake has been associated with lower measured exhaust-related pollution. Separately, studies have recorded better lung development and fewer new childhood asthma diagnoses as air quality improves.
These findings do not answer every question, but together they provide a stronger basis for hope than any single headline.
Are electric vehicles associated with cleaner air?
Battery electric vehicles produce no exhaust emissions where they are driven. Whether their growing numbers make a detectable difference to the surrounding air is a question researchers can investigate.
A study published in The Lancet Planetary Health in 2026 examined electric vehicle registrations and satellite measurements of nitrogen dioxide across 1,692 Californian areas between 2019 and 2023.
Within an area, an increase of 200 electric or plug-in vehicles was associated with approximately 1.1% lower satellite-measured nitrogen dioxide. The relationship remained after adjustments for factors including population, education, working from home and fuel prices. It also remained when researchers excluded 2020 to check whether pandemic restrictions explained the finding.
The researchers checked ground-level pollution monitors too. These showed an association in the same direction, although the statistical uncertainty narrowly included no change. An earlier Californian study had also found a downward association between EV uptake and nitrogen dioxide, but that pollution result was not statistically conclusive.
The newer satellite findings therefore add useful evidence that the transition towards electric vehicles is being accompanied by measurable improvements in exhaust-related air pollution. They remain observational findings, rather than proof that EVs alone caused the reductions.
Does cleaner air translate into healthier children?
There is encouraging evidence here too—including from Britain.
The Children’s Health in London and Luton study, known as CHILL, recruited 3,414 children aged six to nine before London’s Ultra Low Emission Zone, or ULEZ, began operating in 2019.
Researchers measured their lung function annually, comparing London children with children in Luton, which had no equivalent clean-air zone.
Initially, London children had lower average lung function. Over the following four years, their estimated nitrogen dioxide exposure fell faster than in Luton, and their lung function grew faster.
By the end, the initial difference in the main breathing measure, FEV₁, had disappeared. This measures how much air someone can forcefully breathe out in one second. Not every breathing measure showed complete catch-up, but the improvement was encouraging.
CHILL evaluated a real policy intervention as a natural experiment. Children were not randomly allocated to different environments, so other explanations cannot be completely excluded. Nevertheless, researchers measured changes in children’s breathing rather than simply predicting benefits.
The study did not establish how many asthma cases ULEZ prevented, or attribute the improvement specifically to electric vehicles.
Have researchers observed fewer new asthma cases?
Yes. A Californian study published in JAMA followed 4,140 children initially free of asthma, across three groups studied between 1993 and 2014. Researchers recorded new asthma diagnoses through follow-up questionnaires.
For the pollution reductions examined, declining nitrogen dioxide was associated with approximately 20% lower asthma incidence, while declining fine-particle pollution was associated with approximately 19% lower incidence. These were separate analyses of overlapping changes, so the percentages cannot be added together.
Another study from the same wider Californian research programme measured lung function annually in 2,120 children. Across successive groups growing up in cleaner air, the proportion with clinically low FEV₁ at age 15 fell from 7.9% to 3.6%.
These are complementary findings, although they are not wholly independent confirmations because they come from the same research programme.
They support the possibility that cleaner air can help children develop healthier lungs and reduce the likelihood of developing asthma.
What did the original EV–asthma paper do?
A paper published in Environmental Research in 2025 brought vehicle electrification and childhood asthma together in one analysis.
Researchers at the University of Toronto combined US childhood asthma surveys, pollution estimates and vehicle sales data from 2013–2019. They estimated the portion of childhood asthma attributable to traffic pollution, then examined its relationship with electric and conventional vehicle sales.
Higher EV sales were associated with a lower estimated burden of traffic-pollution-related childhood asthma. The headline estimate was approximately one fewer new case for every 264 new electric vehicles sold, with a reported 95% confidence interval of 113–401 vehicles per case.
That figure needs care. The pollution-related asthma cases were estimated, not individually identified as caused or prevented by vehicle emissions. The study found an association; it did not establish a dependable conversion rate between cars sold and children protected.
Its statistical analysis allowed for some geographical differences and time trends. However, EV uptake can accompany higher incomes, better housing, other clean-air measures and replacement of older vehicles. These could explain part of the association.
State-level asthma and sales figures also cannot reveal whether cleaner vehicles replaced polluting journeys in the neighbourhoods where children were most exposed. The reported confidence interval does not capture every possible bias.
How does Britain compare?
Britain is further ahead than the US in adopting electric cars. In 2024, battery electric cars and plug-in hybrids together accounted for nearly 30% of new UK car sales, compared with just over 10% in the US. These figures concern new sales, rather than all cars on the road, and plug-in hybrids retain a combustion engine.
We have also substantially reduced conventional vehicle exhaust pollution. Between 1990 and 2024:
- Nitrogen oxide emissions from UK cars and taxis fell by 88%.
- Fine-particle exhaust emissions from road transport fell by 93%.
Much of this progress resulted from tighter emissions standards and began before widespread EV adoption. It shows that sustained action can substantially reduce harmful emissions.
An illustration—not a UK prediction
Britain registered approximately 473,000 new zero-emission cars in 2025. Applying the US paper’s headline association to that number produces approximately 1,800 fewer new childhood asthma diagnoses in a year. Carrying through its reported statistical interval gives roughly 1,200–4,200.
These are not measured UK benefits, a validated forecast or a confidence interval for Britain. They are arithmetic illustrations of what the scale might look like if the US relationship applied here.
The calculation assumes comparability despite differences in pollution, population and vehicle use. Vehicle categories also differ: the US study included plug-in hybrids, while this calculation uses UK zero-emission cars. Other factors could explain part of the association.
Fewer diagnoses during a year could mean cases delayed as well as prevented altogether. We cannot confidently add successive years to calculate a cumulative number of children protected.
The figure illustrates a possible human scale. The measured pollution and health findings provide the firmer foundation for the argument.
Cleaner electricity matters too
Britain is also changing how electricity is generated.
In 2024, renewables and nuclear supplied approximately 65% of electricity generated in the UK, compared with about 41% in the US. Britain’s final coal-fired power station closed that September, while coal still supplied approximately 15% of US electricity. These comparisons exclude imported electricity.
Replacing fossil-fuel combustion with sources such as wind and solar offers opportunities to reduce air pollution alongside carbon emissions. Cleaner vehicles and cleaner electricity can therefore bring complementary benefits.
The EV–asthma paper did not separately quantify the health benefits of cleaner power generation, so we cannot simply add another number to its results. Nor do these studies assess all pollution associated with manufacturing vehicles and batteries.
Carbon dioxide and lung-damaging pollutants are different things. Climate policies and clean-air policies overlap, but their effects need separate assessment.
Reasons for hope, without overstating the evidence
Not every clean-air intervention has produced a detectable health improvement. An earlier evaluation of London’s original Low Emission Zone found modest pollution reductions but no clear improvement in children’s lung function or asthma symptoms during the study period. The later CHILL study examined a stronger policy using a different design.
Cleaner transport will not prevent every case of asthma. EVs also leave pollution from tyre and road wear that still needs attention.
Nevertheless, the evidence is encouraging in several connected ways: greater EV uptake has been associated with lower measured exhaust-related pollution; cleaner air has been associated with better lung development; and falling pollution has accompanied fewer new childhood asthma diagnoses.
These findings do not prove every step occurred in the same children, or establish precisely how many cases electrification prevents. They do show movement in the right direction.
For people who know the burden of asthma, that offers a tangible reason to keep improving the air: the possibility of more children growing up with healthier lungs, alongside the longer-term protection of our climate.
The potential benefits extend beyond asthma.
Air pollution contributes to heart disease, stroke, COPD, lung cancer and respiratory infections. Reducing exposure therefore offers opportunities to protect health throughout life—from children’s developing lungs to the hearts and lungs of older adults. These wider benefits cannot be calculated from the EV–asthma study, but they strengthen the public-health case for cleaner air.
Studies and sources
Electric vehicles and air pollution
- Zero-emissions vehicle adoption and satellite-measured nitrogen dioxide air pollution in California, 2019–2023
— The Lancet Planetary Health, 2026. Observational evidence linking greater EV uptake with lower satellite-measured nitrogen dioxide. - California’s early transition to electric vehicles: Observed health and air quality co-benefits
— 2023. Associations with asthma emergency-department visits and air pollution; the nitrogen dioxide result was not statistically conclusive.
Cleaner air and children’s respiratory health
- Impact of the Ultra Low Emission Zone on lung function growth in children in London: the CHILL study
— The Lancet Public Health, 2026. Compared measured lung development in children in London and Luton.
Read the research team’s plain-language explanation. - Association of Changes in Air Quality With Incident Asthma in Children in California, 1993–2014
— JAMA, 2019. Falling nitrogen dioxide and fine-particle pollution were associated with fewer new childhood asthma diagnoses. - Association of Improved Air Quality with Lung Development in Children
— New England Journal of Medicine, 2015. Measured improvements in children’s lung development as air quality improved. - Association of Changes in Air Quality With Bronchitic Symptoms in Children in California, 1993–2012
— JAMA, 2016. Additional evidence concerning respiratory symptoms, including in children with asthma. - Impact of London’s low emission zone on air quality and children’s respiratory health
— The Lancet Public Health, 2018. An earlier evaluation that did not detect clear improvements in children’s respiratory health following modest pollution reductions.
The EV–asthma estimate and its limitations
- Emerging evidence for the impact of Electric Vehicle sales on childhood asthma: Can ZEV mandates help?
— Environmental Research, 2025. The US observational modelling study behind the estimate of one fewer new asthma case per 264 new EV sales.
Important: The UK figure of approximately 1,800 fewer new childhood asthma diagnoses is an illustrative calculation, not a measured UK benefit or a validated forecast. The range of approximately 1,200–4,200 carries through the US study’s reported statistical interval; it is not a confidence interval for Britain. Observational associations do not establish causation, and fewer diagnoses during a year may represent cases delayed as well as prevented.
UK and US transport and electricity statistics
- International Energy Agency: Global EV Outlook 2025 — trends in electric car markets
— Source for the comparison of UK and US new electric-car sales in 2024. - Department for Transport: Domestic air pollution emissions from transport in 2024
— Source for long-term reductions in UK vehicle exhaust emissions. - Department for Transport: UK vehicle licensing statistics, 2025
— Source for approximately 473,000 new zero-emission car registrations in 2025. - Department for Energy Security and Net Zero: 2024–2025 performance report
— Includes the reported low-carbon share of UK electricity generation in 2024. - US Energy Information Administration: US energy facts and statistics
— Electricity-generation statistics; this page is updated as newer data become available.
Your immune system and aspergillosis: a video guide
Why do most people breathe in Aspergillus spores without becoming ill? How does the immune system protect us—and why can that same response sometimes contribute to lung damage?
In this video series from the National Aspergillosis Centre, Graham Atherton explores these questions using accessible explanations and illustrations.
Recorded during our November 2026 patient meeting, the videos introduce the immune system and explain how its response helps us understand different forms of aspergillosis.
You can watch the full talk or choose a shorter video on a subject that interests you. No scientific background is needed.
Watch the complete video series:
Your Immune System and Aspergillosis — National Aspergillosis Centre
Watch the full talk
How your immune system fights Aspergillus—and why it can cause damage
The full presentation brings the subjects together: our first-line defences, how immune responses are controlled, and what happens in allergic bronchopulmonary aspergillosis (ABPA) and chronic pulmonary aspergillosis (CPA).
Running time: approximately 56 minutes.
https://www.youtube.com/watch?v=iKIC5aITc0Y
Explore the shorter videos
1. How does your immune system fight Aspergillus?
Macrophages and neutrophils
Meet two types of immune cell involved in defending our lungs. This introduction explains their different roles and uses an analogy to show how a response that protects us can also affect surrounding tissue.
Running time: approximately 7 minutes.
https://www.youtube.com/watch?v=cQwjEUKl8zo
2. How does your immune system know what to attack?
Immune tolerance explained
An effective immune system needs controls as well as weapons.
This video introduces how the immune system learns to recognise the body’s own tissues and how it regulates its responses. It provides background for understanding why immune activity needs to be carefully balanced.
Running time: approximately 11 minutes.
3. When your immune system causes damage
Inflammation explained
Inflammation is part of the body’s protective response. This video explores why that response can become harmful when it is excessive or continues for too long.
It builds on the earlier clips to explain why controlling inflammation can be an important part of treatment.
Running time: approximately 5 minutes.
4. Why does ABPA keep coming back?
Mucus, eosinophils and biologics
This video explores the relationship between Aspergillus, inflammation and mucus in ABPA. It introduces eosinophils and discusses why treatments that target parts of the immune response are of interest.
Running time: approximately 7 minutes.
5. Why is CPA so difficult to treat?
Chronic pulmonary aspergillosis explained
This clip considers why Aspergillus can persist in damaged lungs and why the interaction between the fungus, lung structure and immune defences makes CPA challenging to treat.
Running time: approximately 4 minutes; final edited length may vary.
Watch at your own pace
You do not need to watch everything at once. Start with a subject that interests you, pause whenever you wish and return to the other videos later.
If the immune system is unfamiliar territory, the macrophages and neutrophils video is a useful starting point. The immune tolerance and inflammation clips then explain how those defences are controlled.
The illustrations and analogies simplify complex processes. They are intended to make the ideas easier to follow rather than describe every detail of how immunity works.
Questions and support
If a video prompts a question, you are welcome to bring it to one of our online meetings.
Members share their experiences of living with aspergillosis, while Graham can add context, help find reliable information or identify questions to discuss with your healthcare team.
Find out about NAC online support meetings.
These videos provide general education. Different forms of aspergillosis involve different processes, and your own circumstances will affect your treatment. Do not change medicines on the basis of these videos; discuss treatment questions with your healthcare team.
When you struggle to hear or understand your doctor
A question arising from the NAC Thursday Sessions
During a recent NAC Thursday Session, members shared experiences of communicating with healthcare professionals and trying to get their concerns heard.
One difficulty raised was following a doctor’s speech. This prompted a wider question: what happens when a patient is listening carefully but cannot understand enough of the conversation?
This article develops that question. It considers hearing and sight difficulties, problems using written information, and how patients and healthcare teams can prepare for a clearer conversation.
Straining to catch the words
Sometimes the difficulty starts before you can think about what the doctor means. You are concentrating on recognising the words themselves.
While you are working out one sentence, the next has already begun. You lose the thread and become increasingly tense. Your heart sinks as you realise that important information is passing you by.
Perhaps the doctor speaks quickly or quietly, their accent is unfamiliar, or they use medical terminology. Background noise can add to the difficulty. If you are also hard of hearing, tired, breathless or anxious, following the conversation can take considerable effort.
You ask for something to be repeated, but still cannot follow it. You may feel embarrassed about interrupting again or worry about using up the appointment.
So you nod—and may leave unsure about a medicine, a test result or what happens next.
You may be trying very hard to understand. The way the conversation is happening needs to change.
The responsibility should not fall on the patient
Patients can explain what would help, but they should not have to keep overcoming embarrassment or repeatedly asking for the same adjustment.
The clinician is responsible for explaining information clearly, responding to communication difficulties and checking understanding. NICE guidance recognises that accents and dialects can affect communication and recommends adapting explanations, avoiding jargon and summarising important information.
A short appointment does not remove that responsibility. Understanding the treatment plan is an essential part of receiving care.
Simply asking “Do you understand?” may not reveal a problem. Someone who feels tense or rushed may say yes even when they are uncertain.
Telephone appointments can be particularly difficult
On the telephone, you cannot see the clinician’s face, lip movements or gestures. Poor sound quality can make words harder to distinguish.
You may understand the general subject but miss a medicine name, a dose or a change in treatment. Repeating the same sentence over the same connection may not help.
You can say:
“I’m missing too much of this conversation to understand the advice reliably. We need another way to go through it.”
The clinician should recognise when the format is not working and arrange an accessible way to continue, taking account of how urgently you need care. NHS England’s Accessible Information Standard recognises that some people with hearing loss cannot use telephone services effectively and need alternative communication methods.
There are two things to address: making today’s treatment clear, and preparing better arrangements for next time.
For today: get a treatment plan you can use
If you have struggled to follow the appointment, explain this before the conversation ends:
“I’m still unclear about the treatment plan. Please go through it with me and give me the instructions in a format I can use afterwards.”
The plan should explain, where relevant:
- Which medicines to start, stop or change, including doses, timing and duration.
- Any tests or monitoring needed.
- What happens next and when.
- What to do if symptoms worsen or there is a problem.
- Who to contact with questions.
For many people, having this written down is helpful. NHS advice supports asking for information to be written down and unfamiliar words explained.
But written information only helps if you can read, understand and use it.
If reading or writing is difficult
Some people find reading difficult or cannot read or write. Others have sight loss or cannot use the document they have been given.
You do not need to explain the personal reasons for finding something difficult before asking for help. You can say:
“I find written instructions difficult to use. Could we go through the plan another way?”
Depending on your needs, useful options might include:
- Large print, Braille or an accessible electronic document.
- An audio version or explanation you can replay.
- Easy Read information using clear words and supporting pictures, if that helps you.
- A spoken explanation, one step at a time, with a practical demonstration where appropriate.
- Support from someone you choose.
The Accessible Information Standard specifically covers communication needs related to disability, impairment or sensory loss, including accessible formats and communication support. Difficulty reading or writing can also arise for other reasons; the healthcare team still needs to explain your care in a way you understand.
If sight loss makes it difficult to identify medicines, ask the clinical team or pharmacist how you can distinguish and use them safely.
Agree when and how you will receive the plan
Ask how the instructions will reach you and make sure that method works for you.
If treatment needs to start or change today, explain that you need usable instructions today, rather than waiting for a routine clinic letter.
Providing a document, message or recording does not replace answering your questions and checking that the plan is clear.
For next time: prepare the ground beforehand
If you already know that a particular appointment format is difficult, contact the practice or clinic in advance.
You do not have to write. You can use a contact method that works for you or ask someone to help with your permission.
For example:
“I have hearing loss and cannot reliably follow telephone consultations. Before my next appointment, please agree with me how we will communicate and how I will receive the treatment instructions.”
Or:
“I have sight difficulties and cannot read standard print. Please arrange information in a format I can use before my appointment.”
Ask the service to agree:
- A suitable appointment format.
- Any equipment or communication support needed.
- How the clinician will be told about your needs.
- How you will receive the treatment plan.
- How the arrangements will be confirmed accessibly.
Support might include a quieter room, more time, a hearing loop or professional communication support. Video helps some people who need to see the speaker, but it will not suit everyone. The arrangements should reflect your needs.
Preparing beforehand should reduce the effort you have to make during the appointment.
Ask for your communication needs to be visibly flagged
A diagnosis such as “hearing loss” in your medical history does not necessarily tell staff what to do.
Ask the service to record the practical support you need, for example:
“Needs staff to face her and speak clearly, one point at a time. Telephone consultations are difficult. Important instructions must be provided in an agreed accessible format.”
In England, the Accessible Information Standard requires disability-related communication needs to be identified, recorded, flagged, shared, met and reviewed. The flag should be highly visible to relevant staff—for example, an alert or banner on an electronic record.
It does not have to be literally red. What matters is that staff notice it and act.
Ask your GP practice and hospital clinic to confirm that your needs are recorded. Do not assume that information entered by one service is already visible to every other service. Ask for communication needs to be included in referrals and handovers.
You can check at the appointment:
“Have you seen my communication-support alert?”
That is useful, but the responsibility for acting on the information remains with the service.
Check the explanation—not the patient
The clinician can invite you to describe the plan in your own words, explaining that this checks how clearly they have communicated it.
You can also say:
“Let me explain what I think I need to do, so you can check I’ve understood.”
This should not feel like an examination or a memory test. It is an opportunity to identify anything that needs explaining differently.
NICE recommends that clinicians summarise the main information and check understanding at the end of a consultation.
If someone accompanies you, the clinician should continue to address and involve you directly, using your chosen support to help the conversation.
If your needs are not addressed
If you are still unclear, ask another member of the team for help:
“I have explained that I cannot follow the information, but I still do not understand my treatment. Please arrange for someone to go through it with me in a way I can use.”
For hospital care in England, the Patient Advice and Liaison Service (PALS) can help you raise concerns and communicate with the hospital. You can seek help without starting a formal complaint.
For a GP practice, ask the practice manager to help arrange communication support. Explain what remains unclear, what would help, and whether a recorded alert has been overlooked.
If the problem remains unresolved, ask about the service’s complaints procedure and independent NHS complaints advocacy. Those processes should also be accessible to you.
If you need clarification to use treatment now, contact the clinical team promptly rather than waiting for PALS or a complaint response. PALS cannot provide medical advice.
Understanding is part of your care
Our Thursday Sessions give people space to describe difficulties that may not be obvious during a busy appointment. Members share experiences, while questions that arise can lead us to useful information and guidance.
This conversation highlighted how much effort someone may be making simply to follow the words being spoken.
For today, you need a treatment plan you understand and can use. For next time, the service should have communication support ready. You should not have to pretend to understand.
Find out about the NAC online support meetings.
This article develops a communication issue raised during a Thursday Session without identifying participants. Hearing, sight and reading examples are wider guidance and do not describe individual attendees. The NHS flagging and PALS arrangements described apply to England; arrangements elsewhere may differ.
What’s Up Docs? — health conversations worth listening to
Sometimes hearing a subject explained clearly can make it easier to understand your health, make sense of treatment or prepare questions for your healthcare team.
Members of our NAC Thursday Sessions recommended What’s Up Docs?, the BBC Radio 4 podcast presented by doctors Chris and Xand van Tulleken. Expert guests join them to explore health questions in an informal, conversational way.
The series covers many subjects. Here are a few starting points that may interest people living with aspergillosis and other lung conditions.
Your nose, mucus and nasal symptoms
Why do we produce mucus, and where does it go? What commonly goes wrong with our noses, and what is the evidence behind treatments such as nasal sprays?
Chris and Xand explore these questions with ear, nose and throat surgeon Katherine Whitcroft. They also discuss our sense of smell and how it changes throughout life.
This subject came up during a Thursday Session when members were sharing experiences of sinus symptoms, postnasal drip and nasal treatments.
Listen: What do you need to know about your nose?
Understanding your lungs
Respiratory consultant Professor Robin Condliffe explains how lungs work and what happens when things go wrong.
The conversation covers asthma, COPD, respiratory infections, smoking and air pollution, as well as the relationship between lung health and our environment. It provides broader background for anyone interested in understanding their lungs.
Listen: How can we look after our amazing lungs?
Calcium, vitamin D and bone health
Endocrinologist Dr Sagen Zac-Varghese explains what calcium does, its relationship with vitamin D and its role in bone health. The discussion includes supplements and ways of strengthening bones.
Listen: Are we getting enough calcium?
A closer look at osteoporosis
The companion episode continues the conversation, specifically discussing osteoporosis, who is at risk and why it is more common in women.
Bone health was another subject mentioned by our Thursday group. One member described how hearing a clear explanation had helped them feel less apprehensive about treatment. Understanding why a treatment is offered can make it easier to discuss concerns and ask questions.
Listen: Doctors’ Notes: Calcium
The programme’s episode notes correct a website address mentioned in the recording: the Fracture Risk Assessment Tool website is fraxplus.org.
Finding more episodes
In the UK: Browse the series on BBC Sounds.
Outside the UK: Look for What’s Up Docs? — BBC Radio 4 in your usual podcast app, or browse the series on Apple Podcasts.
The episode links above provide alternatives to BBC Sounds, which is no longer available to listeners based outside the UK. Availability may vary by country and platform.
Bring the conversation to our group
If an episode prompts a question or reminds you of an experience, you are welcome to bring it to one of our online support meetings.
Members share their own experiences, while Graham can add context, clarify a point or identify something worth checking afterwards. Useful questions can also become subjects for future discussions or information on this website.
These programmes provide general health information and are not specifically about aspergillosis. Your circumstances, medicines and treatment plan may affect how the information applies to you. Discuss treatment changes with your own healthcare team.
The Thursday Sessions: finding people who understand everyday life with aspergillosis
12 November 2026
Living with aspergillosis can involve a lot of explaining. Why you are tired after something you enjoyed. Why you hesitate before accepting an invitation. Why a prescription delay or an unanswered question can feel like a significant problem.
At the NAC Thursday Sessions, there are often people who recognise those experiences without needing much explanation.
This week we welcomed a new attendee and had four people present by the end. It was an informal conversation, with time to get to know one another and compare experiences. We touched on several subjects rather than exploring one in depth, but a familiar thread ran through the discussion: the everyday adjustments involved in living with a long-term lung condition.
Enjoying something—and needing time to recover
People talked about wanting to stay active, finding activities they enjoy, and then needing more recovery time than they once would have.
An outing can be worthwhile and still leave you exhausted. Equally frustrating is the experience of gradually building up activity, beginning to feel you are making progress, and then having another infection interrupt it.
There was recognition around the group. Nobody needed persuading that ordinary activities could take considerable effort.
We also chatted about adapting the things we enjoy. Gardening, for example, can mean growing a few plants or enjoying the garden while someone else helps with heavier work. Accepting that help can make it possible to keep something important in your life, even when your contribution changes.
Wanting company while worrying about infections
Another familiar subject was the balance between social contact and concern about becoming unwell.
People described different approaches to busy indoor places, wearing masks and meeting outdoors. Winter makes some of those choices more difficult, particularly when activities move back inside.
The conversation did not produce one answer that would suit everyone. It offered something simpler: a chance to talk honestly about wanting to join in while also feeling apprehensive.
That can be difficult to explain to people who do not share those concerns. Within the group, there was an understanding of why an invitation to a café or a social gathering might involve more thought than others realise.
Having space to explain
Appointments and communication with healthcare services also came up.
People shared frustrations about continuity of care, getting questions heard and sorting out practical matters such as prescriptions and sputum samples. We touched on how difficult it can be to explain a concern when you are already feeling exhausted or breathless.
These were personal experiences rather than a verdict on any service. What the meeting provided was time to describe a problem, hear whether others recognised it, and think about questions or possible sources of help.
An unclear patient-portal message prompted a similar exchange. We could not establish what had happened, but the conversation helped identify somewhere to seek clarification.
Sometimes being able to talk a concern through is a useful first step.
Learning from one another’s experience
The discussion wandered through sinus symptoms, nasal treatments, airway clearance and gardening. People mentioned things they had been shown, prescribed or found helpful.
This is one way peer support can be useful: someone else’s experience may introduce a subject you have not discussed with your own healthcare team, or help you find the words for a question.
It does not mean that everyone should try the same treatment or follow the same routine. Experiences differ, and questions about treatment need individual advice. A reported newspaper story about compost also gave us something to check, rather than an answer to accept without further information.
There is room in these conversations for both practical suggestions and uncertainty.
You can get to know us at your own pace
Welcoming someone new also gave us a chance to explain what people value about the group: talking with others who understand, sharing experiences and gradually becoming comfortable enough to ask questions.
You do not need a prepared question or a detailed account of your health. You can listen, chat about your week, or mention something that has been on your mind. Everyday conversation and laughter are part of the meeting too.
Some weeks we spend longer on a particular issue. Other weeks, like this one, we move between subjects as people get to know one another. Both offer opportunities to make connections and feel a little less alone with the practical realities of illness.
The NAC Thursday Sessions take place each Thursday at 10 am UK time. People affected by aspergillosis, their families and carers are welcome. There is no pressure to speak.
Find out about our online meetings and how to join.
This article shares general themes from the discussion without identifying participants. Personal experiences shared in the group do not replace advice from your own healthcare team.
How Does Your Immune System Fight Aspergillus? Macrophages and Neutrophils Explained
Every day, we breathe in fungal spores, including spores of Aspergillus. Most of the time, our immune system deals with them without us even noticing.
But how does it do that?
In this six-minute video, we introduce two important types of immune cells: macrophages and neutrophils.
Watch: How your immune system fights Aspergillus
Macrophages: the first responders
Macrophages are immune cells that patrol our tissues, recognising and engulfing unwanted particles and microorganisms.
In the lungs, specialised macrophages help remove inhaled Aspergillus spores before they can establish an infection.
They also communicate with other immune cells, helping organise the response when additional protection is needed.
Neutrophils: the rapid-response team
Neutrophils are white blood cells that can be recruited quickly when the immune system detects a threat.
They are particularly important when Aspergillus spores begin to germinate and develop into fungal filaments called hyphae.
Neutrophils can attack these growing fungal structures using several antimicrobial mechanisms.
Why does this matter in aspergillosis?
In most healthy people, these defences prevent inhaled Aspergillus spores from causing disease.
However, problems can arise when immune defences are weakened, when the lungs have existing damage, or when immune responses become excessive.
This helps explain why aspergillosis can take several different forms, including allergic bronchopulmonary aspergillosis (ABPA), chronic pulmonary aspergillosis (CPA) and invasive aspergillosis.
The immune system has to achieve a balance: controlling fungi while limiting damage to our own tissues.
Learn more
Explore our information about aspergillosis, immune responses and the different ways Aspergillus can affect the lungs.
You can also join our online patient support meetings to ask questions and discuss topics like this with others affected by aspergillosis.
Damp, mould and mycotoxins: what we know, what we don't, and where to find help
Damp and mould can affect your health. But finding mould in your home does not mean you have been poisoned, and an expensive urine mycotoxin test may not provide the answers you are looking for.
If you have been unwell for a long time, particularly without a clear diagnosis, it is understandable that you might search for explanations. You may have noticed that your symptoms worsen in certain buildings, or encountered alarming information online about toxic mould.
The important message is that damp and mould are genuine health concerns, but many claims about mycotoxin poisoning go further than the scientific evidence supports.
A September 2026 expert review from the American Industrial Hygiene Association (AIHA), Fungal Metabolites in the Indoor Environment, examines what is known about fungal chemicals in buildings and the limitations of tests marketed to people with suspected mould-related illness.
This guide explains the evidence, why doctors may question commercial test results, and what you can do to protect your health.
Should I be frightened of mould in my home?
Searching online for information about household mould can be alarming.
Some websites suggest that ordinary mould exposure causes toxins to accumulate in the body, resulting in permanent damage or a wide range of chronic illnesses.
Finding mould in your home does not mean that you or your family have been poisoned.
There is convincing evidence that damp and mould can affect respiratory health. However, there is not convincing evidence that typical indoor mould exposure routinely causes the widespread systemic mycotoxin poisoning described by some commercial websites.
The colour of mould, including whether it appears black, cannot reliably tell you how dangerous it is.
You should take damp and mould seriously, particularly if someone in your household has respiratory disease, but there is no reason to assume that discovering a patch of mould means you have suffered irreversible harm.
The sensible response is to identify the moisture problem and address it.
Don't panic about mould. Don't ignore damp.
What do we know about the health effects of damp and mould?
Scientific studies have established associations between damp or mouldy buildings and several respiratory problems, including:
- Worsening asthma, wheezing and breathlessness.
- Coughing and irritation of the airways.
- Allergic rhinitis and other allergic symptoms.
- An increased risk of some respiratory illnesses.
Fungi release spores and microscopic fragments containing substances that can stimulate the immune system.
These include fungal allergens, beta-glucans and chitin. In susceptible people, exposure can contribute to inflammation and respiratory symptoms.
Damp buildings may also contain bacteria and other biological or chemical substances. Their combined effects are not completely understood.
This is why it can be difficult to identify one particular substance as the cause of someone's symptoms.
Some people are particularly sensitive to fungal exposure
Not everyone responds to airborne fungi in the same way.
A person without respiratory disease may experience no noticeable symptoms in an environment that causes considerable difficulties for someone with severe asthma or fungal sensitisation.
There are also recognised conditions in which the immune system responds strongly to fungal material.
Allergic bronchopulmonary aspergillosis (ABPA) involves an exaggerated immune response associated with Aspergillus in the airways. It can cause substantial inflammation, mucus plugging and worsening respiratory symptoms.
Severe asthma with fungal sensitisation (SAFS) describes severe asthma associated with sensitisation to fungal allergens.
Hypersensitivity pneumonitis (HP) is an uncommon immune-mediated lung disease triggered by inhaling particular antigens, which can include fungal material. Repeated exposure may cause inflammation deep within the lungs and, in some people, progressive lung damage.
These conditions have different underlying mechanisms, but they illustrate an important principle:
An exposure that causes little difficulty for one person may cause significant illness in another.
They are examples of allergic or other immune-mediated disease, not evidence that mycotoxins have poisoned the person.
Recognising this distinction is important because these conditions can be investigated using established clinical approaches. In HP, identifying and avoiding the responsible antigen can be particularly important.
People with significantly weakened immune systems may also face additional risks from fungal infections.
What are mycotoxins?
Mycotoxins are chemicals produced by certain fungi under particular conditions.
Some mycotoxins are genuinely dangerous. The clearest established human health risks involve contaminated food.
For example, aflatoxins produced by certain fungi on agricultural products can cause serious harm when ingested in sufficient quantities.
But the fact that mycotoxins can be harmful does not mean that mould growing on household walls exposes occupants to dangerous doses of those toxins.
Scientists have detected fungal metabolites in indoor air and dust. Some can have biological effects in laboratory experiments.
However, detecting a substance is not the same as demonstrating that people are exposed to enough of it to cause illness.
The AIHA review concludes that the available evidence does not establish typical indoor mycotoxin exposure as a general explanation for chronic systemic illness in people living or working in damp buildings.
This does not mean that researchers fully understand every effect of indoor fungal exposure. There are still important questions to investigate.
It means that we should distinguish what has been demonstrated from what remains a hypothesis.
Why doesn't my doctor agree that mycotoxins are making me ill?
Imagine that you have experienced persistent symptoms for months or years.
Medical investigations have not provided a satisfactory explanation. You suspect that your home or workplace is contributing, perhaps because you feel worse there.
You discover a company offering a urine mycotoxin test. The result comes back positive.
At last, it feels as though you have an answer.
But when you show the result to your doctor, they do not accept it as proof of mycotoxin poisoning.
That can be frustrating, especially if you already feel that your concerns have not been heard.
Usually, the disagreement is not about whether you are ill. It is about what the test result actually proves.
There are three different questions:
- Are you experiencing genuine symptoms?
- Could damp or mould exposure be contributing to those symptoms?
- Is there reliable evidence that mycotoxins are causing your particular illness?
The answer to the first question may clearly be yes.
The second is also a reasonable possibility, particularly where respiratory symptoms are involved.
But the third requires evidence that commercially marketed urine mycotoxin tests cannot currently provide.
A positive result may indicate that a substance has been detected. It does not establish where it came from, whether the amount was harmful or whether it caused your symptoms.
Your doctor can believe that you are genuinely unwell while disagreeing with the explanation suggested by a commercial test.
Why commercial urine mycotoxin tests may not help
Some companies market urine mycotoxin tests to people who believe that mould exposure is affecting their health.
These tests may produce detailed reports, numerical measurements and apparently precise results.
However, there are important limitations.
Detection is not diagnosis. Finding a chemical in urine does not establish that it has caused illness.
The source may be uncertain. Some mycotoxins can enter the body through food, so a positive result cannot necessarily be attributed to a damp building.
Accepted diagnostic thresholds are lacking. There are no established urine concentrations that reliably diagnose illness caused by indoor mould exposure.
The test cannot establish causation. It cannot demonstrate that your home or workplace caused your symptoms.
The result may lead to unnecessary expense. Some people are offered costly detoxification programmes, supplements or other interventions based on results that do not establish a medically recognised diagnosis.
It is important to distinguish between a laboratory's ability to measure a chemical and a test's ability to diagnose an illness. A measurement may be technically accurate without being clinically useful for the purpose advertised.
Mycotoxin analysis has legitimate applications in research, food safety and exposure monitoring. The concern here is its commercial use to diagnose illness attributed to indoor mould.
The US Centers for Disease Control and Prevention has also warned about the potential for unvalidated urine mycotoxin tests to lead to misleading diagnoses and unnecessary treatment.
Our advice is not to spend money on commercial urine mycotoxin testing as a way of diagnosing illness caused by indoor mould exposure.
What if my symptoms still have no explanation?
Medicine does not have all the answers.
Some people experience persistent symptoms that remain difficult to explain despite appropriate investigations.
The biological effects of complex environmental exposures are still being studied, and there may be interactions between fungal material, bacteria, other substances and individual susceptibility that we do not yet fully understand.
It is reasonable to acknowledge these uncertainties.
However, uncertainty is not proof that a particular explanation is correct.
Fatigue, headaches, difficulty concentrating and other symptoms can have many possible causes. Attributing all of them to mycotoxins could mean that another treatable condition is overlooked.
The most useful approach is to investigate symptoms carefully, consider possible environmental contributors and avoid treatments based on diagnoses that have not been reliably established.
You do not need a positive mycotoxin test for your symptoms to deserve attention.
A practical guide: what can I do if I think damp or mould is making me ill?
1. Keep a record of your symptoms and surroundings
Record what symptoms you experience, when they occur and whether they change in different environments.
You might also record visible dampness, leaks, persistent condensation or strong musty smells.
Photographs of damp patches or water damage may be helpful.
These observations can support a discussion with your healthcare team, although feeling better away from a particular building does not, by itself, prove that mycotoxins caused the illness.
2. Ask your doctor to investigate your symptoms
Rather than asking for a mycotoxin test, explain what you are experiencing and why you suspect your environment may be contributing.
For example:
“I've noticed that my breathing and other symptoms seem worse when I spend time in a damp building. Could we investigate whether asthma, allergy or another condition might be contributing?”
Depending on your symptoms and medical history, your doctor may consider appropriate lung function tests, allergy investigations, blood tests, imaging or specialist referral.
Not everyone needs all these investigations. The aim is to identify conditions for which clinically meaningful tests and treatments are available.
3. Consider other possible explanations
Damp and mould may contribute to illness without necessarily explaining every symptom.
Respiratory infections, asthma, allergies and other medical conditions can produce overlapping symptoms.
Considering alternative explanations is not dismissing your experience. It helps ensure that important medical problems are not overlooked.
4. Fix the damp
This is our most important practical message:
Find the damp. Identify the cause. Fix it.
If there is visible mould, persistent dampness or water damage, the underlying moisture problem needs attention.
Possible causes include leaking roofs or pipes, water penetration, inadequate ventilation, poor insulation and persistent condensation.
Cleaning visible mould without addressing the source of moisture may allow it to return.
People with significant respiratory disease or weakened immune systems should avoid personally disturbing extensive mould contamination and seek appropriate help.
You do not need a urine mycotoxin test to justify repairing a damp building.
In England, government guidance makes clear that landlords should not wait for medical evidence before addressing damp and mould.
Read the UK government's guidance on damp and mould.
5. Get help with housing problems
If you rent your home, report damp and mould to your landlord or housing provider, preferably in writing.
Keep records of your correspondence and photographs of the problem.
If it is not resolved, your local council's housing or environmental health team may be able to help. The procedures and rights available depend on where you live.
Citizens Advice provides independent guidance about housing problems and tenants' rights.
6. Be cautious about expensive tests and treatments
Before paying for a test or treatment advertised for mould toxicity, ask:
- Has the test been independently validated for the condition it claims to diagnose?
- Can it distinguish ordinary exposure from exposure that causes illness?
- Can it identify where the exposure occurred?
- Will the result lead to an evidence-based treatment?
- Are the proposed treatments safe and effective?
Be particularly cautious when the same company offers the test, interprets the result and sells the treatment.
A convincing explanation is not necessarily a correct diagnosis.
Where can I find reliable information and support?
For medical symptoms: Your GP or existing specialist team is the appropriate starting point for clinical assessment.
For damp and mould in housing: Use official government guidance, qualified building professionals and independent housing advice.
For aspergillosis: The National Aspergillosis Centre provides patient education and opportunities to connect with others affected by Aspergillus-related disease.
- Aspergillosis.org — patient information and guidance
- Online aspergillosis support meetings
- UK government guidance on damp and mould
- Citizens Advice — independent housing advice
Support groups can help people share experiences and prepare questions for clinicians, but individual medical decisions should be made with qualified healthcare professionals.
The message to remember
Fix the damp. Investigate the symptoms. Don't pay for answers that a test cannot reliably provide.
Damp and mould can make people ill. Your symptoms deserve investigation, and problems with your home deserve action.
But you do not need to prove that mycotoxins are poisoning you before either concern can be taken seriously.
The best approach is to act on what we know, acknowledge what remains uncertain and avoid allowing frightening claims or expensive, unvalidated tests to distract from practical solutions.
Related articles on aspergillosis.org
We've published several other articles exploring mould exposure, fungal toxins and respiratory health. These provide more detail on the science and practical advice.
- Mycotoxins, Mould and Health: What Does Science Say? — Understanding what research tells us about mycotoxins and their health effects.
- Damp, Mould and Health: Be Careful About Unvalidated Tests and Detox Treatments — Why commercial testing and detoxification claims deserve caution.
- Mould, Toxins and Aspergillus: Understanding What's True and What Isn't — Separating established evidence from common misconceptions.
- Verified UK Resources for Damp, Mould and Health — Finding reliable advice and practical support.
- Air Quality Hub — Our wider collection of information about air quality and respiratory health.
Further reading and scientific sources
American Industrial Hygiene Association (2026). Fungal Metabolites in the Indoor Environment. An expert review examining fungal metabolites, indoor exposure and the limitations of commercial testing. AIHA white paper. Access may require AIHA membership or purchase.
American Industrial Hygiene Association. FAQs About Fungal Mycotoxins and Damp Indoor Environments. Read the AIHA FAQ.
UK government and UK Health Security Agency. Damp and mould: understanding and addressing the health risks. Read the government guidance.
Kawamoto M, Page E (2015). Use of Unvalidated Urine Mycotoxin Tests for the Clinical Diagnosis of Illness. US Centers for Disease Control and Prevention. Read the CDC report.
This article provides general educational information and does not replace individual medical advice. If you develop severe or rapidly worsening breathing difficulties, seek urgent medical attention.
Aspergillosis Research Update – 9 November 2026
This week: Aspergillosis after lung cancer, promising new diagnostic markers, and what RSV infections may mean for people with Aspergillus in their lungs.
Three new studies caught our attention this week. They explore why some people develop aspergillosis, how doctors might improve diagnosis, and why finding Aspergillus in a respiratory sample does not always mean the same thing.
1. Lung cancer survivors may face an increased risk of aspergillosis
Zo S et al. — Medical Mycology, 6 November 2026
A large study from South Korea investigated whether people who had survived lung cancer were more likely to develop pulmonary aspergillosis.
Researchers compared 37,005 lung cancer survivors with 111,015 people without lung cancer. They found an increased risk of pulmonary aspergillosis among survivors, particularly following lung cancer surgery.
There are several possible explanations. Surgery and other cancer treatments can change the structure of the lungs, sometimes leaving damaged areas where Aspergillus may be able to establish itself. Some treatments can also temporarily weaken the immune system.
What does this mean for patients?
Most people who have had lung cancer will not necessarily develop aspergillosis. However, persistent or changing respiratory symptoms after cancer treatment deserve careful assessment.
The study reinforces the importance of considering fungal disease when symptoms cannot be fully explained by the original cancer or its treatment.
The researchers used healthcare records to identify aspergillosis, so not every diagnosis could be independently confirmed.
2. Could our immune response help diagnose aspergillosis?
Chantelot L et al. — Medical Mycology, 6 November 2026
Diagnosing aspergillosis can be difficult. Doctors currently use several different tests, including fungal cultures, scans, antibody tests and tests that detect components of the fungus.
However, these tests do not work equally well in every patient.
Researchers investigated a different approach: looking for proteins produced during the body's immune response to fungal infection.
They examined fluid collected from the lungs during bronchoscopy, including samples from seven patients with invasive pulmonary aspergillosis and four with chronic pulmonary aspergillosis (CPA).
The researchers identified patterns of immune-related proteins that might eventually help distinguish different fungal diseases.
What does this mean for patients?
Instead of looking only for evidence of the fungus, future diagnostic tests might also look at how the body is responding to it.
This could be particularly valuable because people with different immune systems can react very differently to Aspergillus.
The study was small and exploratory. These markers are not yet available as routine diagnostic tests, and much larger studies will be needed to establish whether they are reliable.
3. RSV infections and Aspergillus: infection or colonisation?
Maldonado-Barrueco A et al. — Revista Iberoamericana de Micología, 5 November 2026
Respiratory syncytial virus (RSV) is a common respiratory virus. It can cause serious illness in some adults, particularly those with existing lung disease or weakened immune systems.
Researchers reviewed 11 years of hospital records to investigate patients who had RSV infection and also had Aspergillus detected in respiratory samples.
They found that detecting Aspergillus did not always mean the patient had invasive aspergillosis.
Some patients appeared to have colonisation, where Aspergillus is present in the airways without evidence that it is invading lung tissue. Others were considered to have probable invasive disease.
What does this mean for patients?
A positive Aspergillus culture is an important finding, but it is not a diagnosis on its own.
Doctors need to consider symptoms, CT scans, other laboratory tests and the patient's underlying health before deciding whether treatment is needed.
This study also highlights why respiratory viruses and fungal disease can be difficult to distinguish, particularly in people who already have damaged lungs.
The study was relatively small, so it cannot establish how frequently RSV leads to invasive aspergillosis.
What connects these three studies?
Although they examine different aspects of aspergillosis, all three illustrate an important principle:
Finding Aspergillus is only part of the story. Understanding the patient is just as important.
The condition of the lungs, the immune system and other illnesses can all influence whether Aspergillus causes disease and how doctors should interpret test results.
This is why diagnosing aspergillosis often requires several different tests and, sometimes, advice from a specialist team.
These research summaries are provided for information and do not replace advice from your own clinical team.
What is an MDT, and why might my aspergillosis be discussed?
If your doctor has told you that your case will be discussed at an MDT, you may be wondering what that means. It is a normal part of managing complex conditions such as aspergillosis and does not necessarily mean something is wrong.
What does MDT mean?
MDT stands for Multidisciplinary Team.
It brings together healthcare professionals with different areas of expertise to discuss a patient's diagnosis, investigations and treatment options.
Aspergillosis can be difficult to diagnose and manage, so having several specialists consider a case together can be particularly helpful.
Who takes part in an MDT?
Depending on the case, the team may include respiratory doctors, infectious diseases specialists, medical mycologists, radiologists, microbiologists, pharmacists and other healthcare professionals.
Each contributes a different perspective, helping the team reach well-informed recommendations.
Why has my case been referred?
There are several possible reasons:
- Your diagnosis is uncertain or your test results need specialist interpretation.
- Your treatment isn't working as expected.
- Your doctor is considering different treatment options.
- Your condition has changed.
- Your healthcare team would benefit from additional specialist advice.
An MDT discussion does not necessarily mean your condition has become more serious.
Will I need to travel to the National Aspergillosis Centre?
Not necessarily.
The National Aspergillosis Centre (NAC) provides specialist advice to healthcare professionals across the UK. Your local doctor may be able to discuss your case with NAC specialists while continuing to manage your care locally.
You can read more about this in Contacting the National Aspergillosis Centre.
What happens during the discussion?
The specialists may review your medical history, CT scans, blood tests, sputum results, current medication and previous treatments.
They consider the available evidence and discuss what further investigations or treatments might be appropriate.
The MDT then makes recommendations to the clinical team responsible for your care.
Will this delay my treatment?
An MDT discussion may take some time to arrange, but it can help your doctors make better-informed decisions and avoid unnecessary investigations or unsuitable treatment.
Urgent assessment or treatment should not be delayed while waiting for a routine MDT meeting.
Will I hear what the MDT decided?
Your own healthcare team should explain the recommendations and discuss any proposed changes with you.
If you haven't heard anything, it is reasonable to ask:
“Has my case been discussed at the MDT, and what were the recommendations?”
Can my case be discussed more than once?
Yes. An MDT may discuss your case during diagnosis, when treatment needs reviewing, or if your condition changes.
Repeated discussions can be part of good ongoing care.
The important thing to remember
An MDT brings specialist expertise together to help your healthcare team make the best possible decisions about your care.
It is a valuable part of managing complex conditions such as aspergillosis, and it does not automatically mean that your illness is worsening.
For more information about NAC's national advisory role, read More Than a Referral Centre: How NAC Supports Patients and Healthcare Professionals Across the UK.
Are Robot Vacuum Cleaners Safe for People with Aspergillosis?
Robot vacuum cleaners can make household cleaning much easier, especially for people living with fatigue or breathlessness. But models that also wash floors use water — could they encourage mould growth and increase exposure to fungal spores?
At a recent National Aspergillosis Centre patient meeting, a discussion about robot vacuum cleaners raised an interesting question.
Modern robot cleaners do much more than vacuum. Some mop floors, wash their own cleaning pads, collect dirty water and dry their equipment automatically.
These features can make cleaning much less physically demanding. However, they also introduce something that fungi need to grow: moisture.
So should people with aspergillosis be concerned?
Robot vacuum cleaners may offer real benefits
For people with chronic respiratory disease, ordinary household cleaning can be tiring.
Vacuuming, bending, moving furniture and mopping floors may provoke coughing or breathlessness. A robot cleaner can reduce some of this physical work.
Regular removal of settled dust may also be useful, since household dust can contain fungal spores, allergens and other particles.
However, vacuum cleaners vary in how effectively they capture fine particles. A well-sealed machine with effective filtration is preferable to one that allows collected dust to escape through its exhaust.
Robot cleaners also cannot reach every area, so they do not eliminate the need for other cleaning.
Why might a robot mop encourage mould growth?
Fungal spores are naturally present in household dust and indoor air.
Most do not begin growing simply because they are present. They need suitable conditions, particularly moisture and a source of nutrients.
Robot cleaners that mop floors may contain several places where these conditions develop:
- Dirty-water tanks: Water collected from floors may contain dust, skin cells, food residues and other organic material.
- Mop pads: Damp fabric can retain dirt and moisture after cleaning.
- Docking stations: Water may accumulate in washing trays, drainage channels and other hidden compartments.
- Dust containers: If dust becomes wet, it may provide a suitable environment for microbial growth.
The problem is not the brief use of water to clean a floor. It is moisture remaining inside the equipment for prolonged periods.
Some manufacturers specifically warn that stagnant water and damp cleaning pads can encourage mould or bacterial growth.
Does this mean the machine will spread Aspergillus spores?
Not necessarily.
There is an important difference between a machine having conditions suitable for mould growth and actually increasing someone's exposure to airborne Aspergillus spores.
If mould develops inside a dirty-water tank or cleaning pad, disturbing contaminated material could potentially release fungal particles.
However, there is currently insufficient direct evidence to conclude that properly maintained robot mop-vacuums increase airborne Aspergillus exposure or cause aspergillosis.
The type of microorganism growing inside a poorly maintained machine may also vary. Bacteria, yeasts and other fungi can all be involved.
A musty smell suggests that cleaning and maintenance are needed, but does not establish that Aspergillus is present.
The sensible approach is therefore precautionary maintenance, rather than avoiding these machines altogether.
What about the water left on floors?
Most robot mops use relatively small amounts of water, particularly on hard flooring.
If the floor dries promptly, fungal growth is unlikely to be encouraged simply by mopping.
However, problems may arise if water accumulates:
- Under furniture or appliances.
- Along skirting boards.
- In flooring joints or damaged seals.
- Beneath rugs or mats.
- On surfaces unsuitable for wet cleaning.
Repeatedly wetting an area that cannot dry properly may eventually create favourable conditions for mould.
The general principle is to avoid persistent dampness, whether cleaning is done manually or by a robot.
What should I look for when choosing a robot cleaner?
For someone with aspergillosis, useful features may include:
Effective filtration: Look for good fine-particle filtration and a well-sealed dust collection system. A HEPA-labelled filter alone does not guarantee that the complete machine prevents dust leakage.
Automatic mop drying: Some docking stations use warm air to dry pads after washing. This may reduce the time they remain damp.
Removable water tanks: Tanks that are easy to empty, wash and dry are preferable to inaccessible compartments.
Accessible cleaning trays: Hidden areas that collect dirty water should be easy to inspect and clean.
Straightforward maintenance: A complicated machine that is difficult to clean may not be the best choice, regardless of how many automatic features it offers.
Self-cleaning features are helpful, but they do not make a machine maintenance-free.
How can I reduce the risk of mould growing inside my robot cleaner?
A few practical habits can make a substantial difference.
After wet cleaning
- Empty dirty-water tanks promptly, ideally after each cleaning session.
- Rinse tanks and remove visible debris according to the manufacturer's instructions.
- Wash reusable mop pads and ensure they dry thoroughly.
- Check that automatic drying cycles have completed successfully.
- Wipe away water collecting in docking-station trays or compartments.
Regularly
- Inspect the machine for visible mould, persistent dampness or unpleasant odours.
- Clean filters, brushes and dust containers according to the manufacturer's instructions.
- Replace worn or persistently contaminated pads.
- Check that cleaned floors are drying properly.
- Follow the manufacturer's recommendations for cleaning products; unsuitable chemicals can damage the machine or create irritating fumes.
Do not assume that a self-cleaning docking station never needs cleaning.
What if I discover mould inside the machine?
If you notice visible mould or persistent musty odours, stop using the wet-cleaning function until the problem has been addressed.
Where possible, ask someone who does not have significant respiratory vulnerability to clean or replace contaminated components.
Avoid dry brushing or shaking visibly mouldy material indoors, as this may disperse particles.
Wash removable hard surfaces as instructed by the manufacturer, dry them thoroughly and replace porous components that cannot be cleaned adequately.
Do not mix cleaning chemicals or add disinfectants to the machine unless the manufacturer specifically permits them.
If contamination is extensive or repeatedly returns, replacing affected components — or the appliance itself — may be more sensible than repeated cleaning.
Are traditional vacuum cleaners safer?
Not automatically.
Conventional vacuum cleaners can also release dust if their filters are ineffective, seals are poor or containers are emptied carelessly.
Bagless vacuum cleaners may expose users to a cloud of collected dust during emptying.
Robot cleaners may reduce direct exposure during routine cleaning, particularly if they operate while the user is elsewhere.
However, emptying their dust containers and maintaining their filters still require care.
For people who are particularly vulnerable to fungal exposure, having another household member empty and maintain the cleaner may be helpful.
Should people with aspergillosis avoid robot mops?
There is no good evidence supporting a general recommendation to avoid them.
For many patients, the reduction in physical effort may be valuable.
The main considerations are whether the appliance captures dust effectively, dries its wet components and can be maintained without creating unnecessary exposure.
People with severe immune suppression or other particular clinical vulnerabilities may need more individualised advice from their clinical team.
For most households, a well-maintained robot cleaner is likely to be more useful than a poorly maintained one, regardless of whether it has a mopping function.
The important message
Water-based robot cleaning is not inherently dangerous for people with aspergillosis.
The potential problem is allowing dirty water, damp pads and organic debris to remain inside the machine long enough for microorganisms to grow.
Good filtration, regular maintenance and thorough drying can help reduce avoidable exposure.
And importantly, robot cleaners can reduce the physical burden of household cleaning — something that matters to people living with chronic lung disease.
The aim is not to make the home completely free of fungal spores, which is impossible.
It is to reduce unnecessary exposure while making everyday life easier.
Further reading
- US Environmental Protection Agency: A Brief Guide to Mold, Moisture and Your Home
- Xiaomi: Why a Robot Vacuum's Water Tank May Develop an Odour
- iRobot: Roomba Combo Care and Maintenance
This article provides general household guidance for people living with aspergillosis. Individual precautions may differ for people with significant immune suppression or other respiratory vulnerabilities.
Prepared following a discussion at a National Aspergillosis Centre patient meeting.