Project Summary (UH3) The Environmental Influences on Child Health Outcomes in Puerto Rico (ECHO‐PRO) project leverages an active birth cohort in Puerto Rico (PROTECT cohort) that has initiated child follow‐up (CRECE cohort) to better understand environmental exposures and their effects on birth outcomes and children's health in Puerto Rico – an underserved, highly exposed population. “Puerto Rico Testsite for Exploring Contamination Threats (PROTECT)” is an NIEHS Superfund Research Program (SRP) cohort that started recruiting in 2011 and will continue through 2019 (P42ES017198). PROTECT tests the hypothesis that exposure to phthalates and chlorinated volatile organic compounds (CVOCs) contributes to the unusually high rate of preterm birth (<37 weeks gestation) in Puerto Rico. The “Center for Research on Early Childhood Exposure and Development in Puerto Rico (CRECE),” a Children's Environmental Health Center (CEHC), awarded jointly by NIEHS and the Environmental Protection Agency (EPA) in 2015 (P50ES026049), follows up on children born in the PROTECT cohort. CRECE is studying the impact of exposures to particulate matter and phenols and modifying factors on physical, reproductive and neurodevelopment among children in northern Puerto Rico. ECHO‐PRO will leverage the PROTECT/CRECE cohort (570 children at birth) and infrastructure, and recruit an additional 1100 pregnant women (100 in the UG3 and 1000 in the UH3) and their children (estimated N=990 at birth) collecting ECHO‐Wide approved elements for follow‐up assessments, repeated information on their environmental exposures, biomarkers of intermediate effect, and respiratory, physical, reproductive, and brain development.