Chemical exposures in the womb can lead to what biologists call organizational effects - that is, impacts on the developing child that are irreversible. How were developmental problems associated with chemical exposures during pregnancy first discovered? And how did these discoveries influence policy? With me to discuss chemicals and child development is Tracey Woodruff. Tracey is a professor in the Department of Epidemiology and Population Health at Stanford University, where she co-leads the UCSF/Stanford Environmental Research and Translation for Health Center. She is an expert on environmental pollution exposures and impacts on health, with a focus on pregnancy, infancy and childhood, and health equity. Tracey was elected to the National Academy of Medicine in recognition of her pioneering work advancing environmental health and reproductive justice.