Air pollution is a significant global environmental risk factor which have been increasingly linked to neurodegenerative diseases. Especially the smallest particulate matter, fine (PM2.5) and ultrafine particles (UFP) can penetrate deeply into the biological system, even reaching the brain. Furthermore, the chemical composition of these pollutants substantially impacts health effects. Understanding the physicochemical aspects of air pollution is vital when considering brain health, yet this knowledge remains inadequate in the context of regulatory actions. Therefore, identifying the key sources and physicochemical compositions of air pollution concerning brain health is essential. For instance, it is known that living near busy traffic increases the likelihood of neurodegenerative diseases. So far, research demonstrates that UFPs appear to be the most promising candidates for effects on the central nervous system, as they can be effectively transported within human tissues, even reaching the well-protected brain, and transport toxic components due to their high surface area. Overall, more multidisciplinary research on this important topic is required.