The emergence of ambient air pollution and especially fine particulate matter PM2.5 has taken a centre stage as a key environmental risk factor in neurodegenerative disorders. To provide evidence about the complex relationships between neuroinflammation and air pollution, our analysis is based on the empirical research carried out during the last few years. Recent evidence shows that PM2.5 enters the central nervous system (CNS) through the olfactory bulb and the systemic circulation, which leads to the cascade of nitro-oxidative stress and microglia hyper activation. These incidences damage the blood-brain barrier (BBB) and promote the misfolding of hallmark proteins including amyloid-beta and alpha-synuclein, thus playing a role in the pathogenesis of Alzheimer and Parkinson diseases. The molecular processes and pathways that are observed, the current research limitations, which are primarily the complexity of multi-pollutant interactions and future opportunities, such as epigenetic biomarkers, AI-based predictive modelling have been outlined in the present paper. The findings highlight the importance of the fact that air pollution is not just an issue related to respiration it is a major changeable threatening condition to brain health on a global scale.