Cognitive and social-emotional impairments are a pressing public health concern, as they compromise school and job performance and personal relationships in millions of individuals in the U.S. and globally. Understanding early origins of such impairments and identifying potentially modifiable factors are a high priority. Epigenetic effects are reported for prenatal environmental exposure such as lead (Pb), pesticides, bisphenol A, and stress and nutrient deficiencies, such as folate or iron deficiency (ID). Most studies consider single exposures. However, exposure to mixtures of environmental toxicants, nutrient deficiencies or harmful dietary additives, and stressors is common. This pilot study will explore epigenetic changes and neurodevelopmental outcome with real-life prenatal exposures (mixtures of pesticides, Pb, and ID). The overarching hypothesis is that exposure mixtures change offspring DNA methylation patterns of key neurodevelopmental genes/ pathways related to poorer neurocognitive function later in life. The study builds on NIH-funded projects on neurodevelopmental impacts of pre- and post-natal environmental exposures and ID, involving a cohort of 1,600 full-term infants from a rural area near Beijing. Parent study measures of environmental exposures, iron status, growth, behavior, sensory systems, and motor and cognitive function were collected at birth/ 6 weeks, 9 and 18 months. Over 200 pesticides are assayed in cord blood, as well as heavy metals. Cord blood samples have been saved frozen for genetic and epigenetic analyses. The findings of this and future full-scale studies may point to avenues for intervention to prevent or ameliorate adverse neurodevelopmental effects of real-life prenatal exposure mixtures and nutrient deficiencies.