Tales from Two Cohots

Abstract

Background/Aim: Developmental neurotoxicity is a global health concern. Neurotoxicants easily cross the placenta and fetal blood brain barrier, and their constant presence in maternal blood ensures that the fetus is exposed during critical periods of brain development. Exposure to neurotoxicants has been shown to be associated with children's neurobehavioural outcomes, which in turn has economic, social and health consequences. The aim of this presentation is to describe two large longitudinal pregnancy cohorts investigating associations between prenatal and childhood exposures to neurotoxicants and children's neurodeveloopmental outcomes in a high (Canada) and a low income country (Tanzania).Method and Results: The Alberta Pregnancy Outcomes and Nutrition (APrON) cohort (2189 mothers) was recruited in Alberta, Canada. Data on prenatal exposure to endocrine disruptors (i.e., BPA, BPS, phthalates), heavy metals (i.e., methyl mercury, lead, arsenic, manganese) and perfluorooctane sulfonate (PFOS) during the second trimester of pregnancy has been collected for 563 children. In addition, we have collected biosamples at 3-4 years of age to assess childhood exposure levels. Children’s neurodevelopment and behaviour at 2, 3-4 and 5-6 years is being assessed across multiple domains using standardized measures. The Mining and Health cohort (N = 1056) was recruited in Geita and Magu Districts, Tanzania where artisanal and small scale gold mining is a significant industry. In this cohort, data is being collected on prenatal exposure to mercury, arsenic and other heavy metals, pregnancy and birth outcomes, and early childhood health and development.Conclusions: These two pregnancy cohorts, one from a high income country and the other from a low income country, are providing much needed data on known and emerging neurotoxicants and their long term effects on children’s health, neurodevelopment and behaviour.