Reproductive and Developmental Toxicology (Third Edition): Chapter 42 - Traffic-related air pollution and the developing brain

Air pollution is emerging as an important contributor to the global burden of disease. Initially focused on effects on the respiratory system, and then on the cardiovascular system, research has focused in recent years on potential adverse effects on the nervous system. Human epidemiological investigations and studies in animal models show indeed that air pollution, particularly traffic-related air pollution (TRAP), causes changes in behavior and may be involved in the etiology of neurological, neurodevelopmental, and neurodegenerative disorders. TRAP (e.g., diesel exhaust) is an important contributor to urban air pollution, and fine and ultrafine particulate matter (PM) may possibly be its more relevant components. Exposure to high levels of air pollution is associated with increased oxidative stress and inflammation both in the periphery and in the nervous system, and fine and ultrafine PM can directly access the central nervous system. This chapter focuses on the adverse effects of air pollution on the developing brain and discusses the evidence from human and animal studies suggesting that exposure to elevated air pollution during pre- and early postnatal development is associated with a number of behavioral and biochemical adverse effects. Particular attention is devoted to the association between perinatal exposure to air pollution and increased risk of autism spectrum disorder. Molecular, biochemical, and morphological changes caused by air pollution in the developing brain are discussed as potential mechanisms that may underlie its developmental neurotoxicity. Efforts aiming at curbing air pollution would be important to protect children from possible developmental disabilities.