Smog Induced Cardiovascular Disease: A Review of Epidemiological Evidence and the Case of Punjab, Pakistan

Air pollution, particularly smog, has emerged as a major global health concern, with growing evidence linking its constituents to cardiovascular disease (CVD). This review critically examines the relationship between smog components—including fine particulate matter (PM2.5, PM10), nitrogen dioxide (NO₂), ozone (O₃), sulfur dioxide (SO₂), carbon monoxide (CO), carbon black, and polyaromatic hydrocarbons (PAHs)—and various cardiovascular outcomes such as ischemic heart disease (IHD), stroke, myocardial infarction, and arrhythmia. The pathophysiological mechanisms discussed include systemic inflammation, oxidative stress, endothelial dysfunction, autonomic imbalance, and thrombogenesis, supported by up-to-date epidemiological findings from both high-income and low- and middle-income countries.Special focus is given to Punjab, Pakistan, a region experiencing escalating levels of smog due to rapid urbanization, crop residue burning, and industrial emissions. Case studies and regional data highlight the acute rise in CVD burden correlated with seasonal smog episodes. This review also explores socioeconomic disparities, policy gaps, and mitigation strategies relevant to the region.By synthesizing global literature with local realities, the study underscores the urgent need for targeted environmental and public health interventions. Limitations in existing research and policy frameworks are addressed, and recommendations for interdisciplinary collaboration, early warning systems, and long-term air quality reforms are proposed.