PM2.5 and Cardiovascular Health Risks

PM2.5 is a frequently studied particulate matter metric, due to its wide range of identified overall adverse health effects, particularly cardiovascular health risks. However, there are no clear clinical practice guidelines for air pollution in regard to the prevention of cardiovascular health risks, since most of the current medical guidelines for CVD focus on metabolic risk factors such as hyperlipidemia or diabetes. We sought to determine the relationship between PM2.5 and cardiovascular disease, cardiovascular events, and all-cause mortality by performing a systematic review and meta-analysis. We searched Ovid MEDLINE, Ovid Embase, Ovid Cochrane Database of Systematic Reviews, Scopus, and Web of Science from the database inception to December 2022 for studies that reported an association between PM2.5 and cardiovascular disease, cardiovascular events, and all-cause mortality. We used the DerSimonian & Laird random-effects method to pool hazard ratios or risk ratios separately from the included studies. Of the total 18 prospective studies, 7,300,591 individuals were followed for a median follow-up of 9 years. Compared to low long-term exposure to PM 2.5 levels, an increase in exposure to PM 2.5 levels resulted in an increase in all-cause mortality (HR 1.08 95% CI of 1.05-1.11, P < 0.05). Similarly, when compared to a low long-term exposure to PM 2.5 levels, an increase in exposure to PM 2.5 levels resulted in an increase in cardiovascular disease (HR 1.09, 95% CI of 1.00-1.18, P < 0.05) and an increase in cardiovascular disease mortality (HR 1.12, 95% CI of 1.07-1.18, P < 0.05). Increased exposure to PM 2.5 levels is significantly associated with an increased risk of all-cause mortality, cardiovascular disease, and cardiovascular disease mortality. Although federal primary and secondary standards are in place, those standards are not low enough to prevent CVD health effects. Clinicians should emphasize PM2.5 as a modifiable CV risk factors for their patients to potentially reduce the development of CV complications. A clinical action guideline is needed specifically for air pollution effects on CVD, and how to mitigate them.