Sure, but even so it's not clear that air pollution is a factor. Some researchers recently compiled a "chronology of global air quality" which might be worth a

Sure, but even so it's not clear that air pollution is a factor. Some researchers recently compiled a "chronology of global air quality" which might be worth a review to see if any correlations can be uncovered. At a glance, it looks to me as though Europe and the USA cleaned up their act a long time ago -- so unless pollution exposure in early childhood is somehow especially bad, pollution still has no explanatory power: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7536029/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7536029/ There's also a paper which reviews the "global incidence of young-onset dementia" -- and, again, incidence in the low-pollution USA is higher than in high-pollution developing countries. https://alz-journals.onlinelibrary.wiley.com/doi/full/10.1002/alz.12695 https://alz-journals.onlinelibrary.wiley.com/doi/full/10.100...