Estimates of global mortality burden associated with short-term exposure to fine particulate matter (PM_2·5)

Background: The acute health effects of short-term (hours to days) exposure to fine particulate matter (PM_2·5) have been well documented; however, the global mortality burden attributable to this exposure has not been estimated. We aimed to estimate the global, regional, and urban mortality burden associated with short-term exposure to PM_2·5 and the spatiotemporal variations in this burden from 2000 to 2019. Methods: We combined estimated global daily PM_2·5 concentrations, annual population counts, country-level mortality rates, and epidemiologically derived exposure–response functions to estimate the mortality attributable to short-term PM_2·5 exposure from 2000 to 2019, in the continental regions and in 13 189 urban centres worldwide at a spatial resolution of 0·1° × 0·1°. We tested the robustness of our mortality estimates with different theoretical minimum risk exposure levels, lag effects, and exposure–response functions. Findings: Approximately 1 million (95% CI 690 000–1·3 million) premature deaths per year from 2000 to 2019 were attributable to short-term PM_2·5 exposure, representing 2·08% (1·41–2·75) of total global deaths or 17 (11–22) premature deaths per 100 000 population. Annually, 0·23 million (0·15 million–0·30 million) deaths attributable to short-term PM_2·5 exposure were in urban areas, constituting 22·74% of the total global deaths attributable to this cause and accounting for 2·30% (1·56–3·05) of total global deaths in urban areas. The sensitivity analyses showed that our worldwide estimates of mortality attributed to short-term PM_2·5 exposure were robust. Interpretation: Short-term exposure to PM_2·5 contributes a substantial global mortality burden, particularly in Asia and Africa, as well as in global urban areas. Our results highlight the importance of mitigation strategies to reduce short-term exposure to air pollution and its adverse effects on human health. Funding: Australian Research Council and the Australian National Health and Medical Research Council.