Pesticides pose a public health risk to children living in agricultural communities. Children are particularly vulnerable to the chronic effects of environmental contaminants such as insecticides, due to their size, physiology and behavior. Worldwide, the two most widely used classes of insecticides are cholinesterase inhibitors (organophosphates) and neonicotinoids. While some of the risks of organophosphates are known, to date, there are no longitudinal studies of neurobehavioral or mental health outcomes in adolescents related to spatial patterns of exposure to organophosphates and neonicotinoids. There is also no known research on the associated neurobehavioral health alterations from neonicotinoid exposures in drinking or irrigation water. The proposed study will leverage the parent, NIEHS-funded, longitudinal study of Secondary Pesticide Exposures among Children and Adolescents (ESPINA), that examined 313 children (4-6 years old) in 2008, who live near one of the highest concentrations of floriculture in the Americas, 535 adolescents in 2016, and is planning for a subsequent examination in 2020. The proposed K01 will integrate biological monitoring, household survey, and neurobehavioral examination data and utilize geospatial models and complex statistical techniques to: (1) disentangle pathways of pesticide exposure, (2) study the geospatial determinants of neurobehavioral performance (attention, memory, language, sensorimotor and visuospatial) and outcomes (anxiety and depression) in children and adolescents from pesticide exposure, (3) test pesticide exposure in drinking water and irrigation sources in proximity to floriculture. This is an application for a NIEHS Transition to Independent Environmental Health Research (TIEHR) Career Award for Dr. Georgia Kayser, an early career Environmental Health Assistant Professor in the Department of Family Medicine and Public Health in the School of Medicine at the University of California, San Diego. Dr. Kayser aims to establish herself as an independent environmental health investigator in the areas of pesticide exposure in children and adolescents and associated neurobehavioral outcomes and expand her water and health research to include pesticides in drinking and irrigation water. The award will provide Dr. Kayser with the support to achieve her career development goals: (1) to develop advanced methodological skills in biostatistics and geospatial analysis; (2) to advance training on child development and the interpretation and analysis of neurobehavioral assessment; (3) to acquire skills in spatiotemporal analysis of pesticide exposure data and neurobehavioral outcomes, (4) identify points of intervention and prevention to reduce pesticide exposure in children living in agricultural areas, (5) gain independence. The research and training activities outlined here will generate new research to inform the design of an intervention to be evaluated in an R01, and the application will be completed in year three of this award. This award will also build a strong research network between the United States (USCD) and Ecuador (USFQ).