Comprehensive Review of the Current Literature on Impact of Ambient Air Pollution and Sleep Quality

Abstract Air pollution is associated with increasing morbidity, mortality and decreasing health and life span. Accumulating epidemiological and experimental evidence has shown that exposure to ambient air pollutants such as particulate matters (PM) and gaseous components [e.g., nitrogen dioxide (NO2), ozone (O3)] has detrimental effects on sleep quality. We conducted this comprehensive review to explore the association between ambient air pollution and sleep quality. A systematic search was conducted with the databases of PubMed and Web of Science from inception to November 2019. Overall, 15 studies with 133,695 subjects that evaluated the association between ambient air pollution and sleep quality were conducted in 10 different countries (i.e., USA, Brazil, Canada, Chile, China, Egypt, Germany, Iran, Mexico, and Turkey). Most included studies in the current review have shown that one or more air pollutants have negative influences on sleep quality. Air pollutants might be one of the triggers for poor sleep quality via disparate mechanisms including but not limited to the central ventilator control centers, central nervous system, allergic and non-allergic mechanisms. The possible association between air pollution and select chronic diseases (e.g., mental illnesses, cardiovascular diseases) and behaviors (e.g. impulsivity) may also play important roles in explaining the association between ambient air pollution and sleep quality. The associations and underlying mechanisms between ambient air pollutants and sleep quality need to be clarified with long-term, multi-centered cohort studies.