The impact of air pollution on cardiovascular health outcomes in African populations: a scoping review

Background: Air pollution is a significant environmental risk factor for cardiovascular diseases (CVDs), but its impact on African populations is under-researched due to limited air quality data and health studies. Objectives: To synthesize available research on the effects of air pollution on CVDs outcomes in African populations, identify knowledge gaps, and suggest areas for research and policy intervention. Methods: A systematic search of PubMed was conducted using terms capturing criteria ambient air pollutants (e.g. particulate matter (PM), nitrogen dioxide (NO2), ozone (O3) and sulfur dioxide (SO2)) and cardiovascular diseases and countries in Africa. Exclusions were studies on tobacco smoking, household air pollution and occupational exposures. Results: Six studies met the full inclusion criteria. Most studies were conducted in urban settings and most investigated on particulate matter NO2 and SO2. Five of the 6 studies were performed in South Africa. The studies showed positive associations between exposure to air pollutants and increased incidence of stroke and overall cardiovascular hospitalization and mortality. However, there was considerable variation in study design, pollutant measurement methods, and adjustment for confounders. Conclusions: This review highlights a critical need for standardized research on air pollution and cardiovascular health in Africa. The extremely limited numbers of studies make it difficult to ascertain the true impact of air pollution across the African continent. Future research should include longitudinal studies in different African populations with standardized methods. There is an urgent need to improve pollution monitoring networks, ascertain key sources of exposure, and implement air quality standards.