Asthma and sleep disordered breathing (SDB) are common chronic diseases that disproportionately affect Black children and those living in poor neighborhoods. Household environmental exposures have been shown to increase asthma morbidity and there is strong biologic rationale that these will impact sleep quality, but to date, there have been limited studies of the indoor environment and sleep. Our overarching goal is to define home environmental determinants of sleep disparities and the contribution of sleep disparities to childhood asthma morbidity among low-income, predominantly Black children living in Baltimore City. The home environment is critical as children spend the majority of their time indoors, most in their own home and ~1/3 in the bedroom, the environment most relevant for sleep. We propose to comprehensively study the bedroom environment, including air quality, allergens, microbes, and the relationship with sleep quality in children with asthma. Our prior studies have shown that children in Baltimore City live in homes where bedroom levels of air pollution are three times the concentrations recommend by the World Health Organization Indoor Air Quality standards and that mouse allergen, present in high concentrations, is a driver of asthma morbidity in Baltimore. Bedroom dust and nasal carriage of Staphylococcus aureus are prevalent, and emerging evidence suggests bedroom exposure to this bacteria and its toxic protein products are associated with nocturnal asthma. There is biological plausibility that the bedroom environmental exposures increase inflammation and oxidative stress responses in the upper airway that contribute to risk for and severity of SDB. While there is emerging evidence that environmental exposures impact sleep, there is a need for studies with objective assessments in children. Our research team has extensive experience in the conduct of home environmental monitoring and simultaneously assessing health outcomes in children. In the proposed project, we aim to determine the association between a) bedroom environmental exposures (air quality, allergens, microbes) and sleep quality among children with asthma in Baltimore City 2) bedroom environmental exposures and upper airway inflammation/oxidative stress 3) sleep quality and asthma morbidity among children with asthma in Baltimore City. This comprehensive study of bedroom environment and sleep among inner-city African American children has the potential to provide foundational evidence for environmental drivers of poor sleep quality that are needed to design interventions to reduce sleep and asthma health disparities.