Jia Chenhui, Yan Guangxuan, Yu Xinyi, Li Xue, Xue Jing, Wang Yanan, Cao Zhiguo
Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, School of Environment, Henan Normal University, Xinxiang 453007, China.
Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
Toxics. 2025 Apr 23;13(5):330. doi: 10.3390/toxics13050330.
Fine particulate matter (PM) and Ozone (O) pollution have emerged as the primary environmental challenges in China in recent years. Following the implementation of the Air Pollution Prevention and Control Action Plan, a substantial decline in PM concentrations was observed, while O concentrations exhibited an increasing trend across the country. Here, we investigated the long-term trend of O from 2015 to 2022 in Xinxiang City, a typical city within the Central Plains urban agglomeration. Our findings indicate that the hourly average O increased by 3.41 μg m yr, with the trend characterized by two distinct phases (Phase I, 2015-2018; Phase II, 2019-2022). Interestingly, the increasing rate of O concentration in Phase I (7.89 μg m) was notably higher than that in Phase II (2.89 μg m). The Random Forest (RF) model was employed to identify the key factors influencing O concentrations during the two phases. The significant dropping of PM in Phase I could be responsible for the O increase. In Phase II, the reductions in nitrogen dioxide (NO) and unfavorable meteorological conditions were the major drivers of the continued increase in O. The Observation-Based Model (OBM) was developed to further explore the role of PM in O formation. Our results suggest that PM can influence O concentrations and the chemical sensitivity regime through heterogeneous reactions and changes in photolysis rates. In addition, the relatively high concentration of PM in Xinxiang City in recent years underscores its significant role in O formation. Future efforts should focus on the joint control of PM and O to improve air quality in the Central Plains urban agglomeration.
近年来，细颗粒物（PM）和臭氧（O₃）污染已成为中国主要的环境挑战。随着《大气污染防治行动计划》的实施，PM浓度大幅下降，而全国范围内O₃浓度呈上升趋势。在此，我们调查了中原城市群典型城市新乡市2015年至2022年O₃的长期趋势。我们的研究结果表明，O₃小时平均浓度以每年3.41 μg/m³的速度上升，该趋势具有两个不同阶段（第一阶段，2015 - 2018年；第二阶段，2019 - 2022年）。有趣的是，第一阶段O₃浓度的上升速率（7.89 μg/m³）明显高于第二阶段（2.89 μg/m³）。采用随机森林（RF）模型来识别两个阶段中影响O₃浓度的关键因素。第一阶段PM的显著下降可能是O₃增加的原因。在第二阶段，二氧化氮（NO₂）的减少和不利的气象条件是O₃持续增加的主要驱动因素。开发了基于观测的模型（OBM）以进一步探索PM在O₃形成中的作用。我们的结果表明，PM可以通过非均相反应和光解速率的变化影响O₃浓度和化学敏感性机制。此外，近年来新乡市相对较高的PM浓度凸显了其在O₃形成中的重要作用。未来的工作应集中在对PM和O₃的联合控制上，以改善中原城市群的空气质量。
