High-resolution full-coverage ozone (O3) estimates using a data-driven spatial random forest model in Beijing-Tianjin-Hebei region, China

• Published in: Journal of hazardous materials 2024-12, Vol.480, p.136047, Article 136047
• Main Authors: Wang, Junyu, Qian, Jian, Chen, Jiayi, Li, Sheng, Yao, Menghan, Du, Qianqian, Yang, Na, Zhang, Tao, Yin, Fei, Deng, Ying, Zeng, Jing, Tao, Chenglin, Xu, Xinyin, Wang, Nan, Jiang, Menglu, Zhang, Xingyu, Ma, Yue
• Format: Article
• Language: English
• Subjects: Beijing-Tianjin-Hebei region; Data-driven spatial weight matrices (DDWs); Exposure assessment; High-resolution; Ozone (O3)
• ISSN: 0304-3894; 1873-3336; 1873-3336
• DOI: 10.1016/j.jhazmat.2024.136047

The Beijing-Tianjin-Hebei (BTH) region is severely polluted by ozone (O3). Accurate O3 estimates are essential for identifying high-polluted zones and developing targeted interventions to relieve the burden of diseases. Although many studies have estimated high-resolution O3 concentrations in BTH, the estimation accuracies are still insufficient. In this study, we incorporated data-driven spatial weight matrices (DDWs) into a random forest (RF) model to fully utilize both the spatial homogeneity and heterogeneity of maximum daily 8-h ozone concentration (MDA8O3), and obtained full-coverage MDA8O3 concentrations at 1 km×1 km in BTH from 2014 to 2022. DDW-RF exhibited satisfactory accuracy (10-fold cross-validation R2 =0.937, RMSE=13.919 μg/m3). Overall O3 level presented a spatial pattern of lower in the north and higher in the southeast and showed a distinct temporal trend, i.e., first increasing and then decreasing during 2014–2021 and increasing slightly in 2022. The accurate MDA8O3 estimates indicates that more attention and resources should be poured into the areas adjacent to Bohai Rim, Shandong and Henan. Regulated operation of factories under specific meteorological conditions and upgrading industrial structure and production modes are recommended to mitigate the formation of O3 precursors and reduce O3 generation. Our findings provide evidence and reference for environmental cleaning policies and targeted interventions. [Display omitted] •DDW-RF was utilized to improve the estimation accuracy of O3 in BTH, China.•Areas adjacent to Bohai Rim, Shangdong and Henan are O3 pollution hotspots.•Our findings provide evidence for environmental cleaning policies and targeted interventions.•The regulated operation of factories under specific conditions is recommended.•Upgrading of the industrial structure and production modes are priorities.