Clean Air Where, London (2026)

17/10/2026

New research has looked at whether the air we breathe during pregnancy can affect a child’s development later on.

Researchers followed mothers and children in Ulaanbaatar and found that higher indoor PM₂.₅ exposure during pregnancy was associated with lower cognitive scores at age four, with the strongest association in the first trimester.

It’s one observational study and it has limitations. Exposure was modelled, pollution levels were much higher than in most of the UK and the confidence interval crossed zero, so it does not prove PM₂.₅ lowers IQ by a specific number of points.

But it doesn’t sit on its own.

In the same research programme, pregnant women were randomly given HEPA air cleaners or no air cleaner. The HEPA group had lower particle exposure and their children scored higher on average on cognitive testing at age four.

A 2024 review of 4,860 children also found higher PM₂.₅ exposure during pregnancy and childhood was associated with lower cognitive performance overall.

For me, the bigger point is this: we should be protecting babies and children from air pollution from the very beginning.

If exposure during pregnancy may affect a developing brain, why would our concern stop at birth?

When I was pregnant and travelling on the London Underground, I wore an FFP3 because the particulate pollution down there is so high. After a couple of wears you could see what had collected on the mask 🤮

At home, I ran HEPA filters on high-pollution days and avoided adding unnecessary pollution indoors.

PM indoors can come from candles and incense, frying, wood burning, smoking and va**ng, fragrance products and outdoor pollution coming in.

None of us can remove every exposure. Air pollution is a public-health problem too. But there are things we can do to reduce it.

You can sign up for Government air-quality alerts and get notified when pollution is forecast to be high in your area.

If you’re an employer, teacher, childminder, governor or parent and want to understand how your setting can reduce pollution exposure, you can enquire about Clean Air Where training.

Studies in comments.

10/10/2026

Getting sick does not make your immune system stronger.

I hear this a lot, especially about children.

“They need to catch things to build their immune system.”

But your immune system isn’t a muscle. You don’t need to keep exercising it with viral infections.

Yes, an infection can create immune memory against that particular pathogen. But that is not the same as your whole immune system becoming stronger every time you’re ill.

Some infections can actually do the opposite.

Measles can cause immune amnesia, where some existing immune memory is lost.

There is also evidence that COVID can cause immune dysregulation, including changes to T cells and other parts of the immune response. It can also be associated with reactivation of latent viruses such as Epstein-Barr virus and herpes simplex virus.

So no, getting viruses isn’t some kind of workout for your immune system.

Of course children and adults will still get infections. We cannot prevent every cold, virus or tummy bug.

But repeated illness is not something our immune systems need. It’s not necessary and it’s not helping anyone. It means feeling awful, missing school or work, cancelling plans and passing it around the family.

And sometimes it doesn’t end when the fever or cough does. Post-viral fatigue, lingering respiratory symptoms and other post-viral problems can last for weeks or longer. Long COVID is one example, but post-viral illness is not unique to COVID.

There is an important difference between catching infectious diseases and exposure to the microbial world around us.

Playing outdoors, getting muddy and spending time around soil, plants and animals can expose us to diverse environmental microbes that may support healthy immune development.

That is very different from repeatedly catching flu, COVID, RSV, measles or norovirus.

Mud? Great.

Repeated viral infections? Not something children or any of us need for practice.

05/10/2026

Last week we posted about the common misconception that cold air makes you sick.

As the weather cools, we all start heading indoors more, just as virus season in the UK gets going.

That means more missed school and work, cancelled plans, parents juggling childcare and more pressure on the NHS.

But it doesn’t have to feel completely inevitable.

Handwashing is great. Looking after ourselves matters too. Keeping fit, eating well, getting enough sleep, taking vitamins if they’re right for you, all of that has a place.

But prevention should always be the first layer.

If we can reduce how much infectious material people are exposed to in the first place, that has to be a good thing.

That matters most in places where lots of people are sharing the same air.

Classrooms, nurseries and soft play can be crowded and poorly ventilated. Public transport is another obvious example.

We’re very used to thinking about hand hygiene, but infection prevention isn’t only about what we touch.

What we breathe matters too.

We wouldn’t share our drinks with everyone around us, yet in a poorly ventilated space we can end up repeatedly breathing air that other people have already breathed out.

Ventilation, filtration and respiratory protection all have a part to play alongside the things we already do to stay healthy.

We make jokes about this time of year, but no one actually wants to be smashing off the Calpol, cancelling everything and watching the whole family go down one after another. It’s miserable and disruptive.

If cleaner shared air can help reduce some of that, it’s worth taking seriously.

Prevention first and then everything else on top.

01/10/2026

Cold weather does not give you a “chill” that makes you sick.

What actually happens is that colder weather changes our behaviour. We spend more time indoors, closer together, often in spaces with poorer ventilation, making it easier for respiratory viruses to spread.

Temperature and humidity can also affect virus survival and our respiratory defences, but cold air itself does not create a viral infection.

If cold weather alone made us ill, people in cold climates would be constantly sick. And influenza wouldn’t circulate year-round in some tropical regions.

So no, the flu is not waiting for you in the park.

The bigger issue is what happens when we all head indoors and start sharing poorly ventilated air.

We’re very used to thinking about handwashing, and it still matters. But many respiratory infections also spread through the air when we breathe, talk, cough or sneeze.

In poorly ventilated spaces, infectious particles can build up in the air around us.

Infection prevention isn’t only about what we touch. It’s also about what we breathe.

You may have seen people talking about “burping” the house when temperatures dip. Slightly ridiculous phrase, useful idea.

Opening windows wide for a few minutes to flash ventilate can replace stale indoor air without leaving the house freezing all day. It can also help reduce moisture and condensation, which helps discourage mould.

An indoor air quality monitor can show you what’s happening rather than leaving you guessing.

An air purifier can reduce airborne particles, including PM₂.₅ and some infectious particles.

But an important point:

Air purifiers do not remove CO₂.

If CO₂ is building up, you need ventilation. In a home without mechanical ventilation bringing outdoor air in, that usually means opening a window or door.

So winter doesn’t mean sealing everything up.

Monitor it. Ventilate when needed. Filter particles where useful.

25/09/2026

Wouldn’t it be great if this was every school 😎

25/09/2026

New research involving Imperial College London and UKHSA measured indoor air in 112 London homes and found that routine fragrance-product use could substantially increase indoor PM₂.₅.

Hourly peaks reached:

Incense: 1,293 µg/m³
Oil diffusers: 858 µg/m³
Candles: 622 µg/m³

Exposure was highest in smaller homes and where ventilation was poorer.

This study doesn’t show that lighting a candle will make you ill, and different types of PM₂.₅ aren’t necessarily equally harmful. But it does show how something that feels fairly innocuous can become a significant source of particles indoors.

Another good reminder that indoor air pollution isn’t only something coming in through the window. Sometimes we’re generating it ourselves.

You don’t necessarily need to ban every candle forever. But source control matters, and understanding what we’re adding to indoor air is a pretty good place to start.

Study:
https://www.sciencedirect.com/science/article/pii/S0160412026004290

23/09/2026

Clean Air Where training is now open for autumn and winter bookings.

I offer practical indoor air quality training for schools, nurseries and childminders, in person or remotely.

A big part of the session is explaining the why behind the guidance, policies and everyday procedures settings are already being asked to follow.

Schools and childcare settings already think about the environment around children as part of safeguarding and health and safety: allergens, cleaning products, temperature, infection control, hazardous substances, individual medical needs and emergency procedures.

Indoor air quality is another part of that picture.

We cover ventilation, filtration, CO₂, allergens, respiratory health, pollution and other airborne hazards, and how indoor air quality fits into wider safeguarding, health and safety and wellbeing.

The training is designed to help settings make practical, affordable changes that fit into what they already do and can be sustained over time, rather than creating another complicated system for staff to manage.

Potential benefits can include better comfort and concentration, support for children with asthma and allergies, reduced exposure to respiratory infections and pollutants, better attendance, fewer staff sickness absences and less disruption and cover cost.

For this autumn term I’m offering introductory pricing:

Childminders - £75
Nurseries - £195
Schools - £295

Training can be delivered to the whole team or to a smaller group of relevant staff.

And if you’re not ready to book a whole setting, you can book one place for £75. If you later go ahead with a larger booking, I’ll deduct that £75 from the total.

For bookings or questions: [email protected]

21/09/2026

Did you know there’s a predictable spike in childhood asthma attacks after children return to school?

Research has found hospital admissions can peak around 2 to 3 weeks after the start of term, sometimes called the “September asthma epidemic”.

Asthma + Lung UK reported that emergency asthma admissions for 5 to 14-year-olds in England were more than four times higher in September 2025 than in August.

There isn’t one single cause. Respiratory viruses, allergens, air pollution, mould, dust mites and changes in preventer-inhaler routines can all play a part.

And this is where indoor air quality matters.

Good ventilation helps reduce the build-up of respiratory viruses indoors, while reducing exposure to pollutants and allergens can also help children with sensitive airways.

There’s also a wider shift towards taking allergy safety more seriously in schools. Benedict’s Law now requires covered schools in England to have and publish an allergy safety policy and follow statutory guidance.

It’s specifically about allergy rather than asthma, but it sits alongside the wider responsibility schools already have to support children with medical conditions.

For schools and families, September is a good time to check asthma action plans, inhalers and staff awareness.

And perhaps to think about what children are breathing for six hours a day too.

18/09/2026

Really enjoyed this conversation with LEYF and Louise Thomas from Air Aware Labs about what children are actually breathing - indoors and out.

We talked about outdoor pollution, indoor air, ventilation, filtration, monitoring, cleaning products, green space and the practical things Early Years settings can do.

LEYF have now written up the discussion here:

https://www.leyf.org.uk/news/what-are-our-children-breathing/

Loads in here for Early Years settings and parents to think about.

Thanks again to everyone involved - lots of useful discussion and practical ideas came out of it.

13/09/2026

Well, we’re off to a strong start to the school year.

Kiddo injured his finger in PE and, after making it through the rest of the day with a very swollen finger, we decided we should probably get it X-rayed.

So off to hospital we went.

Because we went in with one problem and really didn’t fancy coming home with another, we wore respirators.

Respiratory infections circulate all year round, and COVID certainly isn’t just a winter virus. But as we head into autumn and winter, flu, RSV and other seasonal nasties start joining the mix too.

Even when an infection is “just” a horrible week or two, that can still mean missed school, missed work, lost income, cancelled plans and the whole family going down one after another, which is pretty miserable, eh.

There are longer-term risks too, including post-viral complications and Long COVID.

So no, we can’t avoid every infection or stop living our lives. But if there’s an easy way to reduce exposure in a higher-risk indoor space, I’m taking it. I try not to let people breathe on me if I can help it.

Kiddo wears a Flo Mask and I wear a fit-tested 3M Aura FFP3, usually bought from The Face Mask Store.

They’re respirators, rather than the loose blue surgical masks most of us got used to seeing in 2020. Surgical masks can provide some protection, but if I have the choice, I’m choosing the respirator.

I may look daft to some people, but I really couldn’t care less.

Respirators are useful for far more than viruses too. Depending on the type, they can help reduce exposure to wildfire smoke, mould spores, fine-particle pollution and occupational dusts.

And right now, there’s a bit more reason to think about respiratory protection again.

(On X) BuDs_UK are reporting COVID infection levels rising in England, and ’s PCR positivity maps are useful for seeing local variation. Flu is starting to creep up too.

Thankfully, no broken finger 🙌
And it’s nice to know it’s unlikely we’ve come out with anything extra either. 🦠

Clean Air Where

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