Air Pollution and Cardiovascular Morbidity in India: A Systematic Review.

Air pollution is a significant environmental determinant of cardiovascular diseases, yet evidence from India remains limited. This systematic review aimed to synthesize studies assessing the associations between ambient and household air pollution and cardiovascular morbidity, including hypertension, ischemic heart disease, stroke, and vascular alterations. A comprehensive search of PubMed/MEDLINE was conducted up to August 2025 following Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines (International Prospective Register of Systematic Reviews: CRD420251131056). Observational and cohort studies were included, and the risk of bias was evaluated using the Joanna Briggs Institute tools. Eighteen studies met the inclusion criteria. Exposure to fine particulate matter (PM2.5) was found to increase systolic blood pressure by 1.4-3.3 mmHg and the odds of hypertension by 4-5% for every 1-10 µg/m3 increment. Household biomass fuel exposure was associated with elevated blood pressure, tachycardia, and early atherosclerotic changes, particularly among women. Long-term exposure to pollutants such as sulfur dioxide, nitrogen dioxide, and PM2.5 showed potential links with ischemic heart disease and stroke. Overall, the findings suggest that both ambient and household air pollution significantly contribute to cardiovascular morbidity in the Indian population. The limited availability of longitudinal and mechanistic data highlights the urgent need for high-quality, region-specific studies to better understand exposure-response relationships and guide public health interventions.