Estimating future PM2.5-attributed acute myocardial infarction incident cases under climate mitigation and population change scenarios in Shandong Province, China

Background: The effects of fine particulate matter (PM2.5) on acute myocardial infarction (AMI) have been widely recognized. However, no studies have comprehensively evaluated future PM2.5-attributed AMI burdens under different climate mitigation and population change scenarios. We aimed to quantify the PM2.5-AMI association and estimate the future change in PM2.5-attributed AMI incident cases under six integrated scenarios in 2030 and 2060 in Shandong Province, China. Methods: Daily AMI incident cases and air pollutant data were collected from 136 districts/counties in Shandong Province from 2017 − 2019. A two-stage analysis with a distributed lag nonlinear model was conducted to quantify the baseline PM2.5-AMI association. The future change in PM2.5-attributed AMI incident cases was estimated by combining the fitted PM2.5-AMI association with the projected daily PM2.5 concentrations under six integrated scenarios. We further analyzed the factors driving changes in PM2.5-related AMI incidence using a decomposition method. Results: Each 10 μg/m3 increase in PM2.5 exposure at lag05 was related to an excess risk of 1.3 % (95 % confidence intervals: 0.9 %, 1.7 %) for AMI incidence from 2017 − 2019 in Shandong Province. The estimated total PM2.5-attributed AMI incident cases would increase by 10.9−125.9 % and 6.4–244.6 % under Scenarios 1 − 3 in 2030 and 2060, whereas they would decrease by 0.9–5.2 % and 33.0–46.2 % under Scenarios 5 – 6 in 2030 and 2060, respectively. Furthermore, the percentage increases in PM2.5-attributed female cases (2030: −0.3 % to 135.1 %; 2060: −33.2 % to 321.5 %) and aging cases (2030: 15.2–171.8 %; 2060: −21.5 % to 394.2 %) would wholly exceed those in male cases (2030: −1.8 % to 133.2 %; 2060: −41.1 % to 264.3 %) and non-aging cases (2030: −41.0 % to 45.7 %; 2060: −89.5 % to −17.0 %) under six scenarios in 2030 and 2060. Population aging is the main driver of increased PM2.5-related AMI incidence under Scenarios 1 − 3 in 2030 and 2060, while improved air quality can offset these negative effects of population aging under the implementation of the carbon neutrality and 1.5 °C targets. Conclusion: The combination of ambitious climate policies (i.e., 1.5 °C warming limits and carbon neutrality targets) with stringent clean air policies is necessary to reduce the health impacts of air pollution in Shandong Province, China, regardless of population aging.