Collaborative Innovation Center for West Ecological Safety (CIWES), Key Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China; The Climate Change Center at National Center for Meteorology, Jeddah 21431, Saudi Arabia.
Collaborative Innovation Center for West Ecological Safety (CIWES), Key Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China.
Sci Total Environ. 2023 Oct 1;893:164871. doi: 10.1016/j.scitotenv.2023.164871. Epub 2023 Jun 16.
Fine particulate matter, with an aerodynamic diameter ≤ 2.5 μm (PM), is a severe problem in China. The lack of ground-based measurements and its sparse distribution obstruct long-term air pollution impact studies over China. Therefore, the present study used newly updated Global Estimates (V5. GL.02) of monthly PM data from 2001 to 2020 based on Geographically Weighted Regression (GWR) by Washington University. The GWR PM data were validated against ground-based measurements from 2014 to 2020, and the validation results demonstrated a good agreement between GWR and ground-based PM with a higher correlation (r = 0.95), lower error (8.14), and lower bias (-3.10 %). The long-term (2001-2020) PM data were used to identify pollution hotspots and sources across China using the potential source contribution function (PSCF). The results showed highly significant PM pollution hotspots in central (Henan, Hubei), North China Plain (NCP), northwest (Taklimakan), and Sichuan Basin (Chongqing, Sichuan) in China, with the most severe pollution occurring in winter compared to other seasons. During the winter, PM was in the range from 6.08 to 93.05 μg/m in 33 provinces, which is 1.22 to 18.61 times higher than the World Health Organization (WHO) Air Quality Guidelines (AQG-2021; annual mean: 5 μg/m). In 26 provinces, the reported PM was 1.07 to 2.66 times higher than the Chinese Ambient Air Quality Standard (AAQS; annual mean: 35 μg/m). Furthermore, provincial-level trend analysis shows that in most Chinese provinces, PM increased significantly (3-43 %) from 2001 to 2012, whereas it decreased by 12-94 % from 2013 to 2020 due to the implementation of air pollution control policies. Finally, the PSCF analysis demonstrates that China's air quality is mainly affected by local PM sources rather than by pollutants imported from outside China.
细颗粒物（PM），空气动力学直径≤2.5μm，是中国面临的一个严重问题。由于缺乏地面测量数据以及其分布稀疏，阻碍了中国长期的空气污染影响研究。因此，本研究使用华盛顿大学基于地理加权回归（GWR）更新的 2001 年至 2020 年月度 PM 数据的全球估计值（V5.GL.02）。将 GWR PM 数据与 2014 年至 2020 年的地面测量数据进行验证，验证结果表明 GWR 与地面 PM 之间具有很好的一致性，相关性更高（r=0.95），误差更低（8.14），偏差更低（-3.10）。使用潜在源贡献函数（PSCF），利用长期（2001-2020 年）PM 数据，确定中国的污染热点和污染源。结果表明，中国中部（河南、湖北）、华北平原（NCP）、西北部（塔克拉玛干）和四川盆地（重庆、四川）的 PM 污染热点非常显著，与其他季节相比，冬季污染最为严重。冬季，33 个省份的 PM 浓度范围为 6.08 至 93.05μg/m，是世界卫生组织（WHO）空气质量指南（AQG-2021；年平均：5μg/m）的 1.22 至 18.61 倍。在 26 个省份，报告的 PM 浓度是中国环境空气质量标准（AAQS；年平均：35μg/m）的 1.07 至 2.66 倍。此外，省级趋势分析表明，在中国大部分省份，2001 年至 2012 年 PM 浓度显著增加（3-43%），而 2013 年至 2020 年由于实施了空气污染控制政策，PM 浓度降低了 12-94%。最后，PSCF 分析表明，中国的空气质量主要受本地 PM 源的影响，而不是受中国境外污染物的影响。
