SEMILLA: Study of Environmental Exposure of Mothers and Infants Impacted by Large-Scale Agriculture

Abstract

Introduction Toxic exposure, combined with poor working conditions, poor nutrition, poverty, maternal stress, and other key social and economic factors, contributes to the loss of developmental potential in young children. Although fungicide use is growing exponentially in the United States and globally, a significant gap exists in scientific knowledge about the neurodevelopmental toxicity of fungicides, and their interaction with critical social and structural determinants of health. Ethylenebisdithiocarbamates are commonly-used fungicides in floriculture and horticulture, which metabolizes ethylenethiourea (ETU). Research indicates that prenatal ETU exposure may cause maternal and neonatal thyroid dysfunction, potentially leading to adverse pregnancy outcomes and impaired neurodevelopment. This presentation will describe the SEMILLA study, a community-engaged cohort study, building on years of previous work, which assesses environmental and occupational toxic exposures among women workers in a major flower-growing region of Ecuador. Methods SEMILLA follows pregnant workers and their infants up to 18 months of age, incorporating prenatal measures of ETU exposure. Methods include obtaining monthly prenatal urine samples and maternal and neonatal blood samples to assess thyroid hormone levels. At each visit throughout the study, we collect detailed data on key social and structural factors including working conditions, environmental exposures in home and work environments, stress, social support, maternal health and lifestyle, socio-economic and demographic factors. We will administer highly sensitive tests to assess neurodevelopment and visual function as well as growth and nutritional status in enrolled infants. Results and Discussion SEMILLA will contribute key data to inform our understanding of how toxic exposure, combined with key social and structural factors, impact child development; data which is critical for developing and initiating appropriate and sustainable interventions in affected communities that promote optimal child health and development, reduce environmentally-associated community exposures, and improve worker health policies. We will discuss important strengths and challenges in the implementation of SEMILLA.