Advancing the Neural Exposome

Epidemiologic genetics studies have revealed key roles for genes in human disease but have also reinforced the need to include environmental exposures in risk assessment for most disorders and conditions. The concept of exposome was developed over two decades ago to include the lifetime composite of chemicals and other exposures that negatively impact health. The brain is uniquely susceptible to a multitude of chemical exposures, especially across specific windows of neurodevelopment, yet may influence the development of neurodegenerative processes as well. Here, we highlight several categories of the best-studied environmental neurotoxicants. These studies, however, also serve to emphasize that so much more must be learned about individual chemical exposures and combinations of chemical exposures to understand their roles in human disease. Newer techniques have been developed to characterize the exposome in large populations, by taking advantage of existing big data collections and incorporating newer tools to assess dynamic aspects of exposures and will also be described below. Finally, high-throughput screens are being developed to rapidly assess relative neurotoxicity for one or more chemicals. Genes identified may be used to the focus laboratory animal studies on select chemicals and to assess in human studies. It is the merging of all these techniques that will move this field most efficiently.