Environmental pollution has impacts on weather conditions and the ecosystem, leading to hazards for human health and living organisms. Environmental pollution consists of coarse, fine, and ultrafine particles with various biological, physical, and chemical characteristics. Such particulate matter (PM) remains in the environment for a long period and can even travel from one continent to another. Air pollutants can move from the atmosphere into the blood circulation and the brain through the respiratory, olfactory, and gastrointestinal systems. Particulate matter (PM) and ultrafine particulate matter (FPM) are highly toxic. They have reactive elements that cause oxidative stress, impair endothelial cells, the blood-brain barrier (BBB), and cerebral vasculature, and cause neurodegenerative changes and brain damage. The main mechanisms connecting environmental pollution and brain damage are cellular and molecular pathways that cause oxidative stress, neuroinflammation, atherosclerosis, and neurodegeneration. Health authorities globally must implement strict policies at regional and international levels to minimize pollution and its associated diseases.