Abstract
Introduction
An increasing number of epidemiologic studies have examined air pollution as a possible contributor to adverse sleep health, but the results were mixed. The aims of this systematic review are to investigate and summarize the associations between exposures to air pollutants and various sleep measures across the lifespan.
Methods
PubMed, CINAHL, Cochrane, Scopus, Web of Science, and PsycInfo were searched through October 2019 to identify original data-based research examining the direct epidemiological associations between air pollution exposures, both ambient and indoor, and various sleep health measures, including sleep quality, sleep duration, sleep disturbances, and daytime sleepiness.
Results
Twenty-two articles from 2010-2019 spanning a wide range of study populations (from early childhood to elderly) and locations (10 Asian, 4 North American, 3 European, 5 other) were selected for inclusion. Due to variation in both exposure and outcome assessments, conducting a meta-analysis was not plausible. Twenty-one reported a generally positive association between exposure and poor sleep quality. While most studies focused on ambient air pollutants, five assessed the specific effect of indoor exposure. Increased exposure to both ambient and indoor pollutants is associated with increased respiratory sleep problems and a variety of additional adverse sleep outcomes in children and adolescents. In adults, air pollution exposure was most notably related to sleep disordered breathing severity.
Conclusion
Existing literature generally show negative relationships between exposure to air pollution and sleep health across different ages, countries, and measures. While many associations between air pollution and sleep outcomes have been investigated, the mixed study methodologies and use of subjective air pollution and sleep measures result in a wide range of specific associations. Plausible toxicological mechanisms remain inconclusive. Future studies utilizing objective sleep measures and controlling for all air pollution exposures an individual encounters may help ameliorate variability in the results reported by current published literature.
Support
yes
Air pollution exposure and adverse sleep health across the life course: A systematic review