[Exposure to methylmercury and neurodevelopment in Indigenous children: a theoretical model]

Neurodevelopment spans from conception to adulthood, encompassing the growth and maturation of the nervous system. Indigenous children living in the Amazon face several circumstances that can adversely impact their neurodevelopment, including prenatal care, birth conditions, malnutrition, infectious diseases, and socioeconomic challenges. Prenatal exposure to toxic substances configures another determinant influencing neurodevelopment. Exposure to methylmercury is associated with the maternal consumption of contaminated fish. After birth, children continue to undergo exposure by breastfeeding or feeding. This trial aimed to develop a theoretical model to find the determinants of neurodevelopment in the first 1,000 days of life considering prenatal exposure to methylmercury in Indigenous children. The seven steps of the Checklist for Theoretical Report in Epidemiological Studies were followed to elaborate this theoretical model. We offer theoretical-methodological reflections on the dimensions and explanatory variables that highlight how exposure to adverse conditions since intrauterine life worsens in the presence of methylmercury, which can damage human health. This theoretical model is unprecedented in considering the complex causal network involved and contributes to research and actions on maternal and child health.