Short-term PM2.5 exposure ups risk of cardiovascular deaths
5 hours ago
Short-term exposure to ambient fine particulate matter (PM2.5) appears to increase the risk of cardiovascular mortality, suggests a study.
One hundred epidemiologic studies (comprising 123 effect estimates) were included in this systematic review and meta-analysis. The investigators estimated the nonlinear curve using a three-stage meta-regression model, combining spline functions and structural causal modelling theory. Based on this curve, they quantified the cardiovascular mortality burden attributable to PM2.5 from 2000 to 2023.
Finally, the optimal alert value was determined via receiver-operating characteristic-like curve analysis.
Each 10-μg/m3 increase in short-term PM2.5 concentration yielded a pooled risk ratio of 1.0090 (95 percent confidence interval [CI], 1.0074‒1.0106) for cardiovascular mortality.
A supralinear pattern emerged in the constructed exposure-response curve. The marginal risk was high at low concentrations, flattened at moderate concentrations (∼75-150 μg/m3), and increased dramatically again at high concentrations (150 μg/m3).
In 2023, the estimated number of cardiovascular deaths attributable to PM2.5 pollution episodes (exceeding the World Health Organization’s first-stage interim target of 75 μg/m3) worldwide was 59,399 (95 percent CI, 38,126‒82,413).
The estimated optimal alert value was 136 μg/m3 (95 percent CI, 129‒148), which could prevent 73.2 percent (95 percent CI, 71.8‒76.6) of attributable deaths while affecting only 32 percent of at-risk person-days, according to the investigators.
“The optimal alert value identified in this study provides critical evidence for developing more scientific, efficient, and health-oriented air pollution warning systems, thereby maximizing public health benefits while minimizing social disruption,” they said.