1. 毕业设计（论文）的内容、要求、设计方案、规划等
城市近地面大气颗粒物（PM）携带多种污染物，是引起城市生态环境恶化和人类疾病的重要因素。
随着城市中汽车保有量的增加，由道路交通排放和二次扬尘等是大气颗粒物污染的重要来源。
城市绿化植物能够有效截留大气颗粒物及携带污染物，对一定范围内的大气颗粒物具有净化作用，能够较好地指示近地面大气颗粒物污染特征和累积状况。
2. 参考文献（不低于12篇）
[1] Liu Qiang,Wang Yang,Liu jingshuang,et,al.Grain-size distribution and heavy metal contamination of road dusts in urban parks and squares in Changchun,China[J].Environmental Geochemistry and Health, 2015, 37 (1):71-82.
[2]J.A.Acosta,A Faz,K,Kalbitz,et,al.Partitioning of heavy metals over different chemical fraction in street dust of Murcia (Spain) as a basis for risk assessment[J].Journal of Geochemical Exploration,2014,144:298-305.
[3]Xingmin shi,jianhui Wang.Comparison of different methods for assessing heavy metal contamination in street dust of Xianyang City, NW China[J].Environmental Earth Sciences, 2013, 68 (8):2409-2415.
