Studies increasingly find links between air pollutants and dementia

https://www.nytimes.com/2025/11/01/health/alzheimers-dementi...

> With increasing evidence that chronic exposure to PM2.5, a neurotoxin, not only damages lungs and hearts but is also associated with dementia, probably not.

PM2.5 is not a neurotoxin, that's an absurd thing to say.

It's literally any particles under a certain size. Whether it's a neurotoxin is necessarily going to depend on what the substance is made of.

Whether your PM2.5 exposure is coming from automobiles or wildfires or a factory, the potential outcomes may be different in different areas of the body. Heck, my PM2.5 meter skyrockets whenever I cook anything in a frying pan, because many of the aerosolized oil droplets are PM2.5.

Previous discussions:

https://news.ycombinator.com/item?id=45157897 (129 comments)

https://news.ycombinator.com/item?id=44846164 (124 comments)

I recently found this blog post about an effective DIY air filter - explicitly filters pm2.5

https://chillphysicsenjoyer.substack.com/p/measuring-my-diy-...

I built one (< $50) and I'm pretty happy with the results. As someone with a life long sensitivity to air quality, the air definitely feels cleaner.

First reaction: air pollutants correlate with urban living, which correlates with access to specialized health care, which correlates with detection of dementia.

live near a highway and can't afford to move, any ideas what I should do

I think they have also done studies in rodents that show pm2.5 diesel particulate decreases insulin sensitivity.

Archive / paywall: <https://archive.is/86eOb>

Dementedness is higher in cities then, right?

What differences in behavior do we see between city and rural?

“ After controlling for socioeconomic and other differences, the researchers found that the rate of Lewy body hospitalizations was 12 percent higher in U.S. counties with the worst concentrations of PM2.5 than in those with the lowest.”

Not a very powerful effect.

These sorts of pollution are largely caused by building massive amounts of car infrastructure and not building transit instead. The health effects extend beyond the direct pollution exposure to lifestyle things such as inactivity social isolation, and more.

And yet the US largely bans healthier, denser living by law. Density grows out of less dense areas, and those less dense areas nearly all have strict density caps preventing density, as well as road infrastructure designed to never allow density. And the dense areas of the country, which already show healthier lives for people and longer lifespans, have similarly tight caps on building more density

All this is to say that we have made a political choice as a society and are now reaping what we have sown. However we can choose something better for the future.