State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.
Sci Total Environ. 2013 Oct 1;463-464:462-8. doi: 10.1016/j.scitotenv.2013.06.055. Epub 2013 Jul 3.
To investigate the long-term trends and variations of the levels, compositions, size distribution and sources of particulate matter (PM), long-term monitoring campaigns of PM10 and PM2.5 were performed in a megacity in China (Chengdu) during the period from 2009 to 2011. The average concentration of PM10 was 172.01±89.80 μg/m(3) and that of PM2.5 was 103.15±59.83 μg/m(3), with an average PM2.5/PM10 of 0.60. Enrichments of the important species indicated that the fractions of crustal elements were higher in PM10 than those in PM2.5, while the abundance of organic carbon (OC) and secondary ions was enriched in the fine PM. Quantitative source apportionments of both PM10 and PM2.5 were performed by PMF. PM10 and PM2.5 in Chengdu were influenced by similar source categories, and their percentage contributions were in the same order: crustal dust was the highest contributor, followed by vehicular exhaust, secondary sulfate, secondary nitrate and cement dust. Crustal dust and cement dust contributed a higher percentage to PM10 than to PM2.5, while vehicular exhaust and secondary particles provided higher percentage contributions to PM2.5. In addition, PMF-HCA was performed to investigate the characteristics of the sources of the clustered samples, identifying three periods: crustal dust dominant-period, secondary sulfate dominant-period and comprehensive source influenced-period. Planting, reduction of precursors, and banning high-emission vehicles should be implemented to control crustal dust, secondary particles and vehicular exhaust in Chengdu. Furthermore, the size-resolved and the period-resolved control would be more effective.
为了研究颗粒物（PM）的水平、成分、粒径分布和来源的长期趋势和变化，在中国的一个特大城市（成都）进行了为期 2009 年至 2011 年的 PM10 和 PM2.5 长期监测。PM10 的平均浓度为 172.01±89.80μg/m3，PM2.5 的平均浓度为 103.15±59.83μg/m3，PM2.5/PM10 的平均值为 0.60。重要物种的富集表明，地壳元素在 PM10 中的分数高于 PM2.5，而有机碳（OC）和二次离子的丰度在细颗粒物中富集。通过 PMF 对 PM10 和 PM2.5 进行了定量源分配。成都的 PM10 和 PM2.5 受到相似源类别的影响，其百分比贡献顺序相同：地壳尘是最高贡献者，其次是车辆排放、二次硫酸盐、二次硝酸盐和水泥尘。地壳尘和水泥尘对 PM10 的贡献百分比高于 PM2.5，而车辆排放和二次颗粒对 PM2.5 的贡献百分比更高。此外，进行了 PMF-HCA 以研究聚类样本来源的特征，确定了三个时期：地壳尘主导期、二次硫酸盐主导期和综合源影响期。在成都，应实施种植、减少前体物和禁止高排放车辆等措施来控制地壳尘、二次颗粒和车辆排放。此外，按粒径和时间段进行控制会更加有效。
