Air pollution has been a focus of several studies on cognitive impairment and dementia risk. There is evidence that tiny air pollution particles can enter the brain, but at this time we can’t say if they play a role in the development of dementia. So, let’s look at the research.
Walton highlighted that epidemiological studies are backed up by human pathological studies and animal studies revealing that PM exposure affects molecular pathways linked to AD
Walton E. L. (2018). Tainted air: The link between pollution and Alzheimer's disease. Biomedical journal, 41(3), 137–140. doi:10.1016/j.bj.2018.06.004