Rising PM2.5 variability fuels mortality from pollution extremes

Abstract

Fine particulate matter (PM2.5) pollution is a leading cause of the global mortality burden, but public health risks from short-term fluctuations, in addition to long-term exposure, have been insufficiently studied. Potentially influenced by climate change, the daily variability of PM2.5 has significantly increased over the past 60 years, particularly in densely populated regions of East Asia, South Asia, and western North America. To quantify the short-term mortality burden exacerbated by this growing variability, we developed a novel method, the Meta-Regression of Distributional Derivatives (MR-ODDs), to construct nonlinear exposure-response relationships from published summary statistics without requiring individual-level data. Using this approach, we estimate that an average of 672,867 (95% CI: 579,452–740,680) deaths per year globally were attributable to short-term PM2.5 exposure between 2000 and 2023. The mortality burden is especially pronounced in regions where intensifying climate variability drives more frequent extreme pollution events. Western North America, in particular, has emerged as the region with the fastest-rising risk from such events. These findings indicate that extreme pollution events pose a new and growing threat to global public health, demanding a shift in policy from managing annual average concentrations to focusing on early warning and intervention for extreme pollution peaks.