ABSTRACT Pediatric sleep disordered breathing (SDB) is associated with an increased risk for a wide range of neurobehavioral and health effects that negatively impact child health, academic performance, and well-being, as well as contribute to chronic health conditions across the lifespan. Minority children, vulnerable to life-long health disparities, bear a disproportionate burden of SDB. Importantly, independent of race, children who reside in disadvantaged neighborhoods are at a more than 3-fold increased risk for SDB, suggesting that exposures in the home and neighborhood environment contribute to SDB, perhaps by stimulating adenotonsillar hypertrophy and airway mucosal inflammation. An improved understanding of the environmental factors that contribute to pediatric SDB is urgently needed to identify interventions for reducing sleep health disparities. To address this need, we will leverage our extensive experience with community and school-based environmental health research to recruit a sample of 300 children, ages 5 to 9 yrs from predominantly low income households attending Boston Public Schools. Children and their families will participate in a clinic and in-home exam, with collection of novel and low burdensome sleep and environmental measurements. We will focus on the role of indoor irritants and allergens while also considering factors such as indoor temperature, humidity, noise, outdoor pollution, respiratory illnesses, and neighborhood and family characteristics. SDB and sleep duration will be assessed with overnight oximetry and 7 day sleep monitoring using a validated device that quantifies movement and sound during sleep. Bedroom dust will be assayed for allergens and endotoxin, and indoor environmental air quality monitors will measure NO2, PM2.5, temperature, humidity and noise. Standardized questionnaires will characterize contextual factors, including social and family characteristics, and child's behavior. We will rigorously characterize atopic status, lung function, and second hand smoke exposure. Primary analyses will quantify the associations between environmental exposures and SDB prevalence and severity and will evaluate the potential effect modification by factors such as atopy. Longitudinal analyses will explore short and longer term variability and the impact of day to day differences in the environment on SDB and sleep. Secondary analyses will further consider the role of environmental factors on sleep duration and sleep continuity and the impact on SDB-related behavioral outcomes. These unique data will identify modifiable factors that contribute to SDB, essential for developing effective environmental control measures aimed at narrowing sleep health disparities.