The National Academies Board on Population Health and Public Health Practice, Board on Environmental Studies and Toxicology, and Board on Children Youth and Families convened a workshop in August 2022 to explore the impact of specific environmental exposures in utero, infancy, early childhood, and adolescence. Experts in epidemiology, toxicology, dose response methodology, and exposure science explored gaps in knowledge around vulnerabilities to environmental hazards as well as opportunities to inform public policy moving forward. This Proceedings of the workshop summarizes important discussions held during the virtual event and outlines recommendations for ways the Environmental Protection Agency can incorporate new research methods into its risk assessments.