Variations of PM_2.5 Concentrations and PM_2.5-related Health Effects in Hunan Province during 2015-2024

Based on the monitoring data of air pollutants in 14 cities (prefecture) in Hunan Province from 2015 to 2024, the global exposure mortality model (GEMM) and the value of statistical life method (VSL) were comprehensively applied to systematically evaluate the PM_2.5-related mortality burden and health economic loss in Hunan Province under the current pollution levels and different PM_2.5 pollution control scenarios. The results indicate: (1) From 2015 to 2024, air quality in Hunan Province demonstrated a consistent improvement trend. Except for Yiyang City, Loudi City and Chenzhou City, the annual averaged PM_2.5 concentrations in the other cities (prefecture) all exhibited a significant downward trend. The decrease rates of PM_2.5 concentration in the cities of Huaihua, Shaoyang and Changsha were relatively larger compared to other cities, with their annual decrease rates all greater than 2.2 μg·m^-3·a^-1. The emission reduction measures was the main reason for the decrease in PM_2.5 concentration in Hunan Province in recent years. (2) In 2022, the excess PM_2.5-related deaths in Hunan Province still amounted to 60 905 (95%CI: 46 474-74 923), and the corresponding health economic loss reached 114.925 (95% CI: 87.698-141.378) billion yuan, accounting for 2.4% (95% CI: 1.8%-2.9%) the gross domestic product (GDP). (3) Based on stricter PM_2.5 pollution control goals, such as achieving the WHO levels of IT-2, IT-3, IT-4, and AQG for annual averaged PM_2.5 concentrations, 10 925, 25 175,34 028 and 46 936 deaths would be decreased, respectively, and health and economic losses would be reduced by 18.0%, 41.5%, 56.0%, and 77.3%, respectively. Due to variations in statistical parameters and methodologies between urban and rural areas, as well as differences in research approaches, the research findings are subject to a certain degree of uncertainty.(4) It is recommended to further refine local statistical methodologies and parameters to enable a more scientifically rigorous assessment of the health impacts of PM_2.5 pollution, and inform region-specific emission reduction strategies and establish more stringent local air quality standards in order to sustainably enhance air quality, and ultimately safeguard public health.