We found elevated HRs for both dementia and AD in relation to PM2.5, and less markedly to NO2, while HRs for warm-season O3 were not elevated. We did this study in a large US cohort (12 million), with national coverage, and including non-urban areas. For both PM2.5 and NO2, we found a larger effect on AD compared to dementia, which may reflect the fact that dementia includes a wide range of diseases with distinct etiologies, some of which may be unrelated to air pollution, while AD is a subset of dementia and a single disease, for which we found a stronger association. On the other hand, we know of no pathophysiologic data, which indicate that air pollution might affect AD more than dementia; data relevant to disease mechanisms would suggest both AD and the broader category of dementia might be affected by air pollution22,23.
We also found that shorter time windows between exposure…
