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Air pollution directly linked to increased dementia risk

(www.nature.com)
275 points rntn | 1 comments | 07 Sep 25 13:13 UTC | HN request time: 0s | source
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dynm ◴[07 Sep 25 15:20 UTC] No.45158964[source]▶
This article repeats the common mistake of conflating correlations and causality. The main results are (1) that PM2.5 exposure is correlated with dementia in humans, (2) some experimental results with mice. This does not establish causality in humans. The paper is careful to stay juuuust on the right side of the line by carefully using "associated" in the right places. But the press release discards that pretense at rigor and jumps straight to full-on claims of causality in people:

> Long-term exposure accelerates the development of Lewy body dementia and Parkinson’s disease with dementia in people who are predisposed to the conditions.

I think it's entirely possible (perhaps even likely) that this is true. But the paper does not show it.

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Avshalom ◴[07 Sep 25 17:08 UTC] No.45160008[source]▶
Oh yeah, sure definitely it's just as likely that people predisposed to dementia move to places with high air pollution...
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1. Aurornis ◴[07 Sep 25 18:28 UTC] No.45160873[source]▶
You’re being sarcastically dismissive, but this is a real possibility. The real world is complicated and disorders with environmental effects are often multi-factorial.

Air pollution might not be the direct cause, it might be a proxy measurement that is correlated with some other factor or factors that contribute to dementia risk. For example, do areas with higher air pollution measurements also have higher or lower rates of something else that is actually contributing to the dementia directly? Do they simply correlate with overall development of the area, and therefore areas with poor pollution numbers also have high levels of water pollution?