Michelle L. Block and Lilian Calderón-Garcidueñas (Extract from PubMed)
Inflammation is increasingly recognized as a causal factor in the pathology and chronic nature of central nervous system (CNS) diseases 1. While diverse environmental factors have been implicated in neuroinflammation leading to CNS pathology, air pollution may rank as the most prevalent source of environmentally induced inflammation and oxidative stress 2. Traditionally associated with increased risk for pulmonary 3 and cardiovascular disease 4, air pollution is now also associated with diverse CNS diseases, including Alzheimer’s disease, Parkinson’s Disease, and stroke.
Air pollution is a multifaceted environmental toxin capable of assaulting the CNS through diverse pathways. Until recently, the mechanisms responsible for air pollution-induced pathology in the brain were unknown. However, despite the variable chemical and physical characteristics of air pollution and the consequent activation of multiple pathways, inflammation and oxidative stress are identified as common and basic mechanisms through which air pollution causes damage 4, including CNS effects. Furthermore, while multiple cell types in the brain respond to exposure to air pollution, new reports indicate that microglia and brain capillaries may be critical actors responsible for cellular damage. In the following review, we describe the complex composition of air pollution, explain current views on the multifaceted mechanisms through which air pollution impacts the CNS, and discuss the new mechanistic findings implicating innate immunity and chronic neuroinflammation in CNS damage induced by air pollution.