Quantitative-Qualitative Literature Review of the Contribution of Remote Sensing Air Pollution and Greenness to Stroke Subtype Occurrence and Risk

Remote sensing (RS) air pollution and greenness investigations provide new information about the risk factors and physiologic mechanisms that change stroke subtype occurrence and risk. Five electronic literature databases (PubMed, Scopus, Embase, Web of Science, Google Scholar) were searched to identify 99 unique published research studies that used RS to evaluate the contribution of ambient air pollution and greenness to four stroke subtypes (cerebrovascular, stroke, ischemic, hemorrhagic). Agreement between ambient aerosol optical depth (AOD)-PM2.5 concentration level values and ambient PM2.5 air monitor measurements was 75.1% (95% CI=72.0-%-78.2%). Record analyses demonstrated the significant contribution of higher ambient AOD-air pollution concentration level values to increased stroke subtype occurrence and risk, but significant protection was rendered by increased RS greenness spatial coverage to decreased stroke subtype occurrence and risk. Environmental risk factors were significantly associated with each stroke subtype. There were significant differences between the eight risk factors and stroke subtype combinations. Single and multiple physiologic mechanisms of immune, inflammation, oxidative stress, and other sources were uniquely associated with individual and multiple stroke subtypes. Literature review findings were used to develop a descriptive-explanatory stroke subtype physiologic mechanism model. The model can assist in the development and implementation of population-based stroke subtype intervention programs.