Ming Lili, Jin Ling, Li Jun, Fu Pingqing, Yang Wenyi, Liu Di, Zhang Gan, Wang Zifa, Li Xiangdong
Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.
Environ Pollut. 2017 Apr;223:200-212. doi: 10.1016/j.envpol.2017.01.013. Epub 2017 Jan 25.
Fine particle (PM) samples were collected simultaneously at three urban sites (Shanghai, Nanjing, and Hangzhou) and one rural site near Ningbo in the Yangtze River Delta (YRD) region, China, on a weekly basis from September 2013 to August 2014. In addition, high-frequency daily sampling was conducted in Shanghai and Nanjing for one month during each season. Severe regional PM pollution episodes were frequently observed in the YRD, with annual mean concentrations of 94.6 ± 55.9, 97.8 ± 40.5, 134 ± 54.3, and 94.0 ± 57.6 μg m in Shanghai, Nanjing, Hangzhou, and Ningbo, respectively. The concentrations of PM and ambient trace metals at the four sites showed clear seasonal trends, with higher concentrations in winter and lower concentrations in summer. In Shanghai, similar seasonal patterns were found for organic carbon (OC), elemental carbon (EC), and water-soluble inorganic ions (K, NH, Cl, NO, and SO). Air mass backward trajectory and potential source contribution function (PSCF) analyses implied that areas of central and northern China contributed significantly to the concentration and chemical compositions of PM in Shanghai during winter. Three heavy pollution events in Shanghai were observed during autumn and winter. The modelling results of the Nested Air Quality Prediction Modeling System (NAQPMS) showed the sources and transport of PM in the YRD during the three pollution processes. The contribution of secondary species (SOC, NH, NO, and SO) in pollution event (PE) periods was much higher than in BPE (before pollution event) and APE (after pollution event) periods, suggesting the importance of secondary aerosol formation during the three pollution events. Furthermore, the bioavailability of Cu, and Zn in the wintertime PM samples from Shanghai was much higher during the pollution days than during the non-pollution days.
2013年9月至2014年8月期间，在中国长江三角洲（YRD）地区的三个城市站点（上海、南京和杭州）以及宁波附近的一个农村站点每周同步采集细颗粒物（PM）样本。此外，在上海和南京的每个季节进行为期一个月的高频每日采样。长江三角洲地区频繁观测到严重的区域性PM污染事件，上海、南京、杭州和宁波的年平均浓度分别为94.6±55.9、97.8±40.5、134±54.3和94.0±57.6μg/m。四个站点的PM和环境痕量金属浓度呈现明显的季节趋势，冬季浓度较高，夏季浓度较低。在上海，有机碳（OC）、元素碳（EC）和水溶性无机离子（K、NH、Cl、NO和SO）也呈现类似的季节模式。气团后向轨迹和潜在源贡献函数（PSCF）分析表明，中国中部和北部地区对冬季上海PM的浓度和化学成分有显著贡献。在秋冬季节观测到上海发生了三次重污染事件。嵌套空气质量预测建模系统（NAQPMS）的模拟结果显示了长江三角洲地区在这三次污染过程中PM的来源和传输情况。污染事件（PE）期间二次物种（SOC、NH、NO和SO）的贡献远高于污染前事件（BPE）和污染后事件（APE）期间，这表明二次气溶胶形成在这三次污染事件中具有重要意义。此外，上海冬季PM样本中Cu和Zn在污染日的生物有效性远高于非污染日。
