Novel evidence for a greater burden of ambient air pollution on cardiovascular disease

Ambient and household air pollution is a major health problem worldwide, contributing annually to approximately seven million of all-cause avoidable deaths, shorter life expectancy, and significant direct and indirect costs for the community. Air pollution is a complex mixture of gaseous and particulate materials that vary depending on their source and physicochemical features. Each material has detrimental effects on human health, but a number of experimental and clinical studies have shown a strong impact for fine particulate matter (PM_2.5). In particular, there is more and more evidence that PM_2.5 exerts adverse effects particularly on the cardiovascular system, contributing substantially (mainly through mechanisms of atherosclerosis, thrombosis and inflammation) to coronary artery and cerebrovascular disease, but also to heart failure, hypertension, diabetes and cardiac arrhythmias. In this review, we summarize knowledge on the mechanisms and magnitude of the cardiovascular adverse effects of short-and long-term exposure to ambient air pollution, particularly for the PM_2.5 size fraction. We also emphasize that very recent data indicate that the global mortality and morbidity burden of cardiovascular disease associated with this air pollutant is dramatically greater than what has been thought up to now.