Air pollution directly linked to increased dementia risk

The maps in the article wasn’t even super clear when you inspect it visually. Didn’t read the study but it can’t be that strongly correlated.

Why is this brought up here every time an association article is mentioned, every undergraduate that took a statistics course has covered the difference between correlation and causation.

We do population level correlation studies because sometimes a double blind study is unethical, and double blind studies is the bar for establishing causation in the medical community. We cannot give one person randomly worse air to breath, and even if it were experimentally feasible it would be ethically impossible because there is strong suspicion we would be harming the subjects.

Let’s discuss the actual data. The dose dependent result that was found is an indicator of a strong relationship. There is a clear potential mechanism of action (Air -> Lungs -> Bloodstream -> Brain). This isn’t a controversial result in the literature, it’s more evidence for what we already know —- air pollution is very bad.

Gotta control for age. Even if air pollution is a major cause of dementia, the disease takes decades to appear.

Utah has the highest birth rate and therefore the youngest population of the 50 states (median age 31.5 years). Florida is not the oldest state, but it's near the top (median age 42.7 years).

Also need to adjust for moving. A lot of people retire to Florida but would have accumulated exposures in wherever they lived most of their working life.

There are obviously lots more factors affecting dementia than air quality.

Also Utah has worse air quality than Miami? Where in Utah? My trips to Utah I remember pristine air but of course I didn’t have an air monitor on board other than my nose.

Edit: Oh I see

>Utah, particularly in urban areas like the Wasatch Front, frequently experiences worse air quality than Miami. Utah's air quality issues are often caused by unique geographical and meteorological conditions. In winter, temperature inversions trap cold, polluted air in the valleys, leading to high levels of particulate matter (PM2.5) pollution. In the summer, heat and sunlight can create high levels of ground-level ozone. The American Lung Association has ranked cities in the Salt Lake City-Provo-Orem area among the worst for ozone and short-term particle pollution.

>In contrast, Miami's air quality is generally "Good" throughout the year, with occasional exceptions. The primary pollutants are also PM2.5 and ozone, but the geographical and weather conditions do not contribute to the same level of pollutant trapping as in Utah. The city has programs in place for air quality monitoring and standards.

Perhaps there are more elderly people in Miami-Dade.

What we should be asking is why aren't countries like China, India, and a lot of others in Asia suffering catastrophic rates of Dementia?

Life is psychologically worse in the cities.

Not all inhalable drugs are the same. Also, not all inhalations are the same.

Your idea could hold for people who smoke cigarettes or use combustion-heated pipes to consume hard drugs like meth or crack, or for people who smoke a lot of poor quality cannabis, especially without any kind of filtering.

It probably doesn’t hold for people who use a dry herb vaporizer to consume cannabis, since the method of consumption doesn’t generate PM2.5 or combustion gases, and the volatile constituents of cannabis are well established to have local and systemic anti-inflammatory effects.

That does not make any sense to me. Now [inhalable] drug users and smokers are "at risk populations" and it's not the drug use or the direct inhaling of smoke, soot, and ash…usually without filtration…that is the issue and problem, but the air pollution is the thing they need to worry about?

But maybe you will be happy to hear that the rates of pollution in the whole European civilization block are orders of magnitude lower than non-European blocks[1]

[1] https://elements.visualcapitalist.com/mapped-air-pollution-l...

An air purifier is pretty cheap and will cut down on indoor pollution from cooking a lot. Or at least that’s how it seemed from the somewhat unreliable sensor I was using.

https://www.nytimes.com/wirecutter/reviews/best-air-purifier...

Are there studies showing indoor air pollution from cooking in a residential setting is linked to dementia?

Wouldn't we see dementia occurrence higher among cooks, then? Or do we?

Well studies like this are often directed at policymakers, who actually can do something about it.

It feels like manipulative lying to me when they show the distribution of PM2.5 in the USA through that heat map, where the scale of pollution only goes to 15 when the most non-European block countries are way higher than 15.

[1] https://elements.visualcapitalist.com/mapped-air-pollution-l... polluted place

I agree. It also reduces the world's dependence on unstable regions.

However, some things that are regarded as renewable (e.g. wood burning, such as the notorious Drax power station in the UK) are more polluting than fossil fuels. Personally I doubt they are even effective at CO₂ reduction. What we need is clean energy.

I'm on that boat. Though no one denies that the climate changes (but rather argue the about degree of human contribution and climate warming), destroying the beauty of nature and polluting the environment should go against global human conscience.

The people who benefit from the status quo are also the people who have the power to change it, and they don't have to live in the polluted areas.

Hopefully China will improve its care of dementia patients. N=1, but a Chinese friend's mother has dementia, and basically the family is expected to care of her full time, there seem to be no facilities (at least not for regular non-rich folks), and even getting a diagnosis was apparently a very hush-hush affair. Seems like it's something that isn't talked much about over there? Again, N=1.

The air pollution in China and India was already awful 30 years ago, so "spike" is not be best choice of word. "Continuation of a high level of dementia" would be better.

It seems to be multifactorial. Per an OpenEvidence query, which cites many recent studies:

"In summary, the mechanism of PM2.5-induced brain damage involves entry via the olfactory system and BBB, activation of glial cells, neuroinflammation, oxidative stress, BBB disruption, and downstream neurodegenerative changes."

Who is to say they don't? Most of those areas have a less developed health infrastructure, so I'd expect the statistics on dementia diagnoses to systemically underreport the issue.

The average age in developing countries is also lower (due to both lower life expectancy and higher birth rate) which is a further confounding value to skew the numbers. Dementia is an old people game, even if it is true that air pollution worsens it.

> This all just seems like gaslighting lies, manipulation, and abuse.

The countries you give all have less than half and usually less than a third the percentage of people over 65.

One of the surprising things about visiting the mountains to do various outdoor activities in nature is how often the air quality is worse than it is at home in an urban area. A big part of this is that "home" is the SF Bay Area and we have consistent winds blowing inland from the ocean, which blows our air pollution to other people (and the air gets noticeable worse when this doesn't happen), but also the air quality is often shockingly poor in rural areas. Wood stoves, diesel generators, and the like in spots where the pollution gets trapped can do a lot even with low density.

On average the air quality is worse in cities than in rural areas, but at least in the United States the difference is smaller than you might expect. In countries that do not take urban air pollution seriously it gets very bad, of course.

It depends. Pollution can be higher in the cities, or it can be higher in areas with high wildfire risk, or it can depend on specific geography which traps polluted air. You have to look at each case individually.

For example, in my state there is a specific more rural area which has a high incidence if heating with wood stoves, and they have higher air pollution that other more urban areas.

Another possibility is that urban areas are richer on average, and therefore might have better air filtration systems in homes and businesses than poorer rural areas. You can't tell without actually gathering the data.