[Spatiotemporal Trends and Driving Factors of PM 2.5 -related Health Burden in Gansu Province, China from 2013 to 2020].

To evaluate the spatiotemporal trends and drivers of PM _2.5 -related health effects in Gansu Province since the implementation of the Air Pollution Prevention and Control Action Plan, the latest global exposure mortality model （GEMM） was adopted to estimate the health burden attributable to PM _2.5 in Gansu Province from 2013 to 2020. The factor decomposition method was used to further quantify the main causes of the long-term changes in deaths attributable to PM _2.5 pollution. The results showed that from 2013 to 2020, the population-weighted PM _2.5 concentration in Gansu Province decreased by 34.57%, and the proportion of people exposed to areas with an annual average PM _2.5 concentration exceeding 35 μg·m ^-3 decreased significantly from 72.89% to 11.61%. Moreover, the number of attributable deaths in Gansu Province declined from 12 826 （95%CI： 7 840-17 408） in 2 013 to 9 814 （95%CI： 6 407-13 036） in 2020, indicating a decrease of 23.48%. Attributable deaths from stroke, chronic obstructive pulmonary disease, lung cancer, and lower respiratory infection declined, whereas deaths from ischemic heart disease increased by 12.11%. Notably, individuals aged 60 years and older accounted for more than 80% of all age-related deaths. The number of deaths attributable to PM _2.5 in central and eastern Gansu Province was significantly higher than that in the Hexi region, and most regions showed a downward trend. The contribution of the total population, age structure, baseline mortality rate, and PM _2.5 concentration to the change in PM _2.5 -related deaths was -1.26%, 16.16%, -9.84%, and -28.55%, respectively. Overall, population aging and a decrease in PM _2.5 concentration were the main factors contributing to the increase and decrease in PM _2.5 -related deaths, respectively. The active clean air policies in Gansu Province have reduced the health burden caused by PM _2.5 pollution, but with the trend of population aging, a significant reduction in PM _2.5 concentration will be needed in the future to avoid more attributable deaths.