Estimates, temporal evolution, and contributors of the stroke burden due to air pollution and non-optimal temperature across G20 nations, 1990–2023

Background: Air pollution and non-optimal temperature are major modifiable environmental risk factors for stroke. This study assessed their attributable stroke burden across G20 countries from 1990 to 2023 and projected trends to 2040. Methods: Using data from the GBD 2023, we analyzed age-standardized mortality (ASMR) and disability-adjusted life year rates (ASDR) for stroke attributable to air pollution (ambient particulate matter and household air pollution from solid fuels) and non-optimal temperature (high and low), and stratified according to the Socio-demographic Index (SDI). Joinpoint regression, decomposition analysis, and ARIMA modeling were employed. Results: The ASMR for stroke attributable to these environmental risks in G20 countries declined from 52.81 (95% UI: 32.05–71.82) to 17.46 (95% UI: 10.58–24.53) per 100,000 from 1990 to 2023, with an estimated annual percentage change (EAPC) of -3.44% (95% CI: -3.57 to -3.30). The ASDR declined from 1,148.95 (95% UI: 693.62–1,576.02) to 394.91 (95% UI: 229.91–550.54) per 100,000 (EAPC: -3.29%, 95% CI: -3.41 to -3.17). This was driven by a sharp decrease in household air pollution burden. However, burdens attributable to ambient particulate matter and high temperature increased or remained stable, exhibiting marked geographical disparities, with low- and middle-SDI G20 nations bearing a disproportionately high burden. Projections to 2040 indicate a continued overall decline, but burdens attributable to ambient particulate matter and high temperature are expected to persist. Conclusions: While progress has been made, ambient particulate matter pollution and high temperature remained important contributors to the estimated GBD-attributable stroke burden in the G20, underscoring the need for targeted intervention.