南京大气细粒子中重金属污染特征及来源解析

利用2011年1月、4月、7月和10月在南京市区和北郊采集的气溶胶样品，研究了南京大气细粒子中zn、Ph、Hg、As和cd5种重金属的污染水平，通过元素相关性分析和因子分析方法，对细粒子中这些重金属的污染来源进行了初步解析。结果表明，南京大气细粒子及其重金属污染严重，北郊普遍比市区严重；As严重超标，cd在南京北郊超标约5倍，zn在市区与北郊的质量浓度均高于其他重金属元素。每种重金属的浓度均随季节而变化。市区细粒子中，As和zn可能主要与燃煤、轮胎灰尘和建筑扬尘等有关，Pb、Hg和cd主要来自交通尘、城市垃圾焚烧等。北郊细粒子中，As、Hg和zn主要来源于燃煤、钢铁冶炼等工业，Pb和cd主要与农作物秸秆燃烧、汽车尾气、道路扬尘等影响有关。

Pollution characters and source apportionment of heavy metals in PM2.1 in Nanjing

Using the atmospheric aerosol samples collected in the urban and the north suburb of Nanjing in January, April, July, and October 2011, the pollution levels of five heavy metals Zn, Pb, Hg, As and Cd in at- mospheric fine particles were studied. The correlation analysis of elements and factor analysis were used to ana- lyze the pollution sources of these heavy metals in fine particles. It is shown that the pollution of atmospheric fine particles and heavy metals in Nanjing is serious, and cannot be igored of which the pollution in the north suburb is generally severer than that in the urban. The As content was found to be excessive, while the content of Cd in the north suburb of Nanjing was about five times over national standard, and both mass concentrations of Zn in the urban and the north suburb were higher than that of other heavy metals. For the fine particles in the urban, the heavy metal elements of As and Zn are mainly related to the coal-burning, tire dust and construction dust, while Pb, Hg and Cd primarily come from traffic dust, municipal solid waste incineration. Each concentration of the heavy metals is subject to seasonal variation. For the fine particles in the north suburb, As, Hg and Zn are chiefly de-rived from coal-burning, metallurgy and steel industry, while Pb and Cd are mainly related with the impact of crop straw burning, automobile exhaust and dust.