Neurodevelopmental disabilities in children from low-to-middle income countries produce a substantial negative impact on societal and economic growth. Many of the causes of developmental disabilities, such as environmental toxins, nutritional deficiencies, psychosocial stressors, are common in resource-poor countries. Young children are particularly vulnerable to environmental exposures because rapid development creates windows of opportunity for toxins to exert their effects. In areas of the world where little research on neurodevelopmental disabilities has been conducted, it is necessary to assess the prevalence and nature of cognitive and behavioral deficits. In Montevideo, Uruguay, there is evidence that children are exposed to multiple heavy metals. However, to date very little research exists in this unique setting to understand the effects of multiple metal exposures on cognition, behavior, and school performance of urban children. There is also no research on how these exposures could be prevented or mitigated. We propose to conduct an investigation of cognitive performance and behavior in 200 children aged 6-7 years from Montevideo, Uruguay. Early school age is a period of important intellectual and social growth, and it sets up children's scholastic trajectories. At this time, learning disabilities often become manifested and diagnosed in children. It is also an age when environmental insults are clearly manifested. The goal of this project is to build research capacity and infrastructure in environmental epidemiology. Also, it is to investigate the relationship between heavy metal exposures (lead, arsenic, mercury), trace metals (iron and manganese) and cognition, behavior, and school performance in children from Montevideo, Uruguay. In the process of collecting data, we will identify key steps in the research process that will require additional training or resources. PUBLIC HEALTH RELEVANCE: Neurodevelopmental disabilities in children from low-to-middle income countries produce a substantial negative impact on societal and economic growth. Many of the causes of developmental disabilities, such as environmental toxins and nutritional deficiencies are common in resource-poor countries. We will conduct an investigation of cognitive performance and behavior in 200 children aged 6-7 years from Montevideo, Uruguay to understand the complex relationship between heavy metal exposures (lead, arsenic, mercury), trace metals (iron and manganese), and cognition, behavior, and school performance in children.