Scientists stunned by children's lung recovery in ultra low emission zone

China has 350 million electric two-wheelers, 20 million EVs. China reduced air pollution from transportation by 80% in a decade.

Delhi: 442. Lahore: 334. Beijing: 16. These are the levels of PM 2.5, one of the principle measures for air pollution, on November 19. How China cleaned up its air pollution – and what that meant for the climate: https://theconversation.com/how-china-cleaned-up-its-air-pol...

A few things standout to me from the article.

1. London when the ULEZ was brought in was already a lot less polluted than historically.Are there gains from that? London was not that bad by global standards.

2. This was followed by the benefits of COVID lockdowns (not a phrase often used!) as pollution dropped much further.

3. Is this effect even across London? Suburbs vs centre, different types of housing etc.? I grew up a the edge of London and the difference in pollution was visible (i.e. you did not need instruments to see signs of it).

4. There was also a reduction in sales of diesel cars which had been heavily encouraged (because of lower CO₂ emissions) in previous decades.

5. As the articles notes, there have been a lot of other changes at roughly the same time. It only mentions one, but there have been significant lifestyle changes, so a lot of potential confounding variables.

Anecdata I was living very close to a busy highway, and my young daughter was wheazing when she had a cold, we had to give her medicine via a nebulizer. When we moved out to the country more, far away from any major roads, these issues all disappeared within a couple months.

There is a chap in London who does some great work with researching and spreading awareness of air pollution:

https://clara.southlondonscientific.com/

He also runs this repo:

https://github.com/southlondonscientific/aeolus

I grew up in a small town in the mountains in Norway. There is a children's "hospital" there (Geilomo Barnesykehus), where kids come to live because they can't live in the cities. Kids with severe asthma, eczema and some other conditions. It started as far back as the 1930s, still unfortunately a problem so kids have to come live there away from their families.

Using scientists being "stunned" should take the same amount of relevance as someone being "slammed" in article titles.

> strongest evidence yet that local clean air zones could help reduce some of the harm caused by pollution during childhood.

It's incredible this is even in debate. It's one of those intuitive things well known since the reduction of coal burning and smog during the industrial revolution in London?

I've needed my inhaler way less since the ULEZ came in.

Visiting London used to mean blowing your nose to black snot for a week afterwards, these days living in London it's pretty good.

My anecdata: I have a Japanese friend who was born in 1964. She grew up in Yokohama for the first ten years. Japan didn't pass its first (serious) environmental protection law until 1967. She said many, many of her friends had asthma. Fast forward 50 years, very few children have asthma in Yokohama.

I will never forget watching this documentary about a Canadian man, Doug Rogers, who went to Japan in 1964 to train martial arts at a dojo. This YouTube video[1], watch it from 1:00 to 1:10. The air pollution is simply stunning. It shows you just how terrible the air pollution was in Tokyo in 1964. Today, it is night and day. The same is true for most large cities in highly industrialised nations.

[1] https://www.youtube.com/watch?v=CBFx1a4L2ig

Seems electric cars produce the same or sometimes more non combustion particulates than ICE cars, eg. bits of road and tire that are flung into the air while driving.

So EVs are better than ICE for air quality, but fewer cars even better.

completely anecdotal. my earliest childhood memories in india were of asthma, sinusitis and constant cold. this was consistent until i was 26 and since then I've moved to the US and lived in New York with 0 days of sinusitis or breathing trouble. and i fallback to trouble breathing when i go home again.

even New York is so much more better than Bangalore or my small village in the middle of coffee farms

What is more amazing to me is I thought this wouldn't be localized. I thought we have on earth and one atmosphere but clearly not? Like the standard of living can wildly change if we change our own local area. We don't need people in Montreal or Paris to come up with a plan?

So unlike greenhouse gases, which can last in the atmosphere for years, seems like NO2 and particulates only stay in the air for less than a day or a few days. This is an amazing little fact because we can start small and call for meaningful reform where we live without requiring a global coordination. Maybe there will be a global consensus later but it doesn't matter because we can start making improvements today within our own local context. The bonus is we will likely also lower our own carbon footprint as we reduce our other emissions. I think this is the "selfish" breakthrough we need to convince people.

When I say it doesn't matter, I don't mean like cross border contamination does not happen but rather that we can improve our own lives with our own action regardless of what others do.

The obvious actionable thing that you can do for your own life is to stop using or being around gasoline or petrol powered two stroke engines such as in a leaf blower. But we can do more. We can completely ban these two stroke engines from being sold at all and that will bring meaningful improvements in weeks, not years.

The problem is to make more impact, we will need to actually get people to give up or retrofit their existing equipment. We will need to educate people about the harms that these things cause and why the change is good. However, in today's siloed world, I don't think it will be easy at all. So perhaps the most difficult part ironically in a very connected and yet siloed world is the marketing of this idea and connecting the required change in behavior with the benefits.

As we saw with the leaf blower example, the costs are concentrated, yes but so are the benefits! The benefits are NOT at all diffuse because guess who benefits the most from not inhaling in gasoline fumes? The person operating the leaf blower!

Link to the original study below, free to access [0]. The key data appear to be this:

>At baseline, 184 (14%) of 1280 children with successful FEV1 measurement in London had a clinically low FEV1 (pre-bronchodilator FEV1 <80% of predicted value) compared with 126 (9%) of 1339 children in Luton (appendix p 8). At the end of the study, these values had dropped to 51 (9%) of 585 children in London and 41 (7%) of 606 children in Luton (appendix p 8).

So the proportion of children with low lung function dropped from 14% to 9% in London, and from 9% to 7% at the comparator site in Luton. It's not that much different, though any improvement is obviously welcome.

https://www.thelancet.com/journals/lanpub/article/PIIS2468-2...

> Initial results showed children's lungs in London were smaller in capacity than those in Luton

Sure but they had to live in Luton

Newsflash, living in a healthy environment is healthy!

- Fuck diesel cars

[0]: https://www.zh.ch/content/dam/zhweb/bilder-dokumente/themen/...

"High diesel-family averages were approximately 1–3 g NOx/km. Most gasoline-family averages clustered around approximately 0.02–0.15 g/km."

[1]: https://publications.tno.nl/publication/34635198/KxBBl3/TNO-...

"TNO tested in-use vehicles directly at the tailpipe. Three diesels with DPFs emitted: 3.9–5.3 million particles/cm³ at warm low idle. The same report measured warm Euro 5 direct-injection gasoline cars without gasoline particulate filters at: 50,000–60,000 particles/cm³ at low idle."

[2]: https://d-nb.info/137495313X/34

"In 2017, the highest diesel was approximately 12 g black carbon/kg fuel, versus roughly 0.4 g/kg for the highest gasoline car. In 2023, the highest diesel was roughly 8 g/kg, versus approximately 0.7 g/kg gasoline."

[3]: https://trueinitiative.org/insights/true-brussels-emissions-...

"approximately 5% of measured Euro 5b/Euro 6 diesel vehicles exceeded one million particles/cm³, and this small group produced more than 90% of the particle emissions from the tested diesel group"

The sad thing is... when the ULEZ went into effect, there were some wild conspiracy theories about it. Suddenly even my father was an expert and viewed it as sinister government intervention - all because of youtube crackpots. I couldn't get him to relate to my view that cleaner air must be a good thing.

I bet if some youtube weirdos pushed out videos against "big soap" for making us unnecessarily clean our hands after pooping... we'd have a growing following of angry "freedom from big soap" people.

Opinion article on this by Sadiq Khan, the London mayor who introduced ULEZ:

https://www.theguardian.com/commentisfree/2026/aug/18/ulez-h...

Isn't this common sense? What is being "stunned" !!

When I talk about health implications I often end up saying "but it's less bad than living next to a street" which statistically many things we spend time optimizing about are.

However most people live next to a busy street ...

While having something done at Stanford's hospitals, at one point I was placed in a room with signs indicating it was on a heavily filtered ventilation system rated for COVID, etc. It was striking to be in an environment with air almost to clean room quality.

This is a reminder that getting an air purifier with high airflow filters (NOT HEPA!) is lifechanging in cities with high pollution levels.

I recommend getting one of these https://www.youtube.com/watch?v=sQGfO4hNb60 and just slapping a MERV 12 to 16 filter on it, you can get a whole roll off aliexpress for cheap and replace them monthly if you wanted to and it would be cheaper than 1 hepa filter replacement. They can also filter vastly more air, while you can keep hepa for 6 to 12 months MERV will filter a lot more air.

I've been meaning to do some data mining on how much PM2.5 differs with even a few hundred feet of elevation. I have a theory that even around Silicon Valley, living even up a little bit in the foothills would have you breathing massively cleaner air most of your life vs living in the pits of the valley. I see it all the time when I'm out there for recreation or just driving, the smoggy haze all over that just sits in the valley and the Bay. It's probably not too tough of a data processing challenge to compare the stats on Purple Air AQI sensors in reasonably close geo proximity vs elevation to get some statistically-significant data on this.

Who knew that populating Earth with mechanical horses that shit into the air is not such a great idea.

So punchline, probably a good idea to electrify all the cars yeah?

And yet we’ve still got people cutting down the enforcement cameras with angle grinders at night

I use air purifiers mounted on my windows, running continuously except in the deep summer and deep winter. This makes my air contain 50-100x fewer particulates than the outdoor air. In contrast, the best I can achieve with floor air purifiers as people have them is a 5-10x reduction. The window purifiers also keep excess CO2 and VOCs out.

cease all travel and live to 88

s/stunned/pleased/

I live in British Columbia so we have fairly good air quality. But with the yearly fires lately summer air some years is poor. So one year with the fires smoking and air quality getting poor I got an air purifier for my kids room and the living room. It is only anecdotal but right away if felt like he had better sleeps. The smoke wasn't thick as it was from fires hundreds of miles away and it wasn't like any of us were hacking or coughing crazy but in hindsight I felt that my young son who would have been effected the most slept better and his breathing at night seemed quieter and easier.

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Scientists stunned healthy living is healthy?

Short-term gains are likely to produce long-term negative effects.

Hormesis and natural selection have been driving factor of evolution for a long time.