Air pollution directly linked to increased dementia risk

Therefore city dwellers are demented and rural dwellers aren't.

(And this says nothing about the effects of noise pollution or aesthetic pollution)

EDIT

Oh come on, it's the obvious conclusion. So discuss already.

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.

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.

There's a lot of interesting confounding factors from an air quality perspective wrt urban vs suburban vs rural. Leaf / lawn blowers. Driving vs walking/public transit. Ground level vs up high. Tradewinds (west coast vs east coast vs AZ dust storm / wildfires).

It would be if it was only pollution but my understanding it’s pm2.5 in general. Rural areas can and do have high pm2.5. Look at the map. It could be agriculture or dust or flora.