Air pollution directly linked to increased dementia risk

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.

(OP makes a good point, just going on a slight tangent here)

We really need a term that sits between correlation and causation in situations where data is difficult to come by. There's such a huge rift of meaning between these terms, and too often 'correlation is not causation' gets wheeled out in a room of people that already know that and are trying to figure out the nuances.

How about plausal? Aka it's rather plausible that there is a causal relationship between two things but causality is hard to prove.

"Air quality and dementia have a plausal relationship".

The bar for plausation is much lower, yet many correlates still won't meet it. "Bad air quality causes dementia" is a categorically different statement than "ice cream sales cause shark attacks", if we establish the category of plausal relationships.