题名乌鲁木齐城市道路沙尘重金属污染空间分布特征及其健康风险评价
作者韦炳干
学位类别硕士
答辩日期2009
授予单位中国科学院.新疆生态与地理研究所
授予地点北京
导师姜逢清,中国科学院新疆生态与地理研究所
关键词重金属
其他题名Heavy metals in urban road dust from Urumqi: Spatial pattern and
学位专业环境科学
中文摘要2007年8月在乌鲁木齐市主城区采集了169个道路沙尘样品。所有样品在实验室按标准方法做前处理,然后利用ICP-MS测定了10种重金属Cd、Cr、Cu、Ni、Pb、Mn、Be、Co、Zn和U的含量。结果表明:重金属Cd、Cr、Cu、Ni、Pb、Mn、Be、Co、Zn和U在道路沙尘中的平均含量分别为1.17、54.28、94.54、43.28、53.53、926.60、2.75、10.97、294.47和2.13毫克/千克。与背景值相比,除了Co和U外,其余8种重金属在道路沙尘中的平均含量均高于其背景值。重金属污染评价显示,10种重金属综合污染指数(IPI)几乎都大于1,表明整个市区都处于轻污染或轻污染水平以上,其中有些道路的重金属综合污染指数在2-3之间,达到了中度污染水平。 对乌鲁木齐城市道路沙尘重金属含量数据进行了富集因子和多变量分析,以识别重金属的主要污染源。结果表明,10种重金属的富集因子平均值从高到低为Cd > Zn > Cu > Pb > Be > Ni > Mn > Cr > Co,其中,Cd、Cu、Pb和Zn的富集因子平均值大于3,表明其受严重的人为污染影响;Cr、Ni、Mn和Be的富集因子平均值在1-3之间,说明其受人为污染的影响较大;而Co富集因子平均值小于1,其主要受自然污染源的影响。Mn、U和Co的主要污染源为自然源;Cu、Pb、Zn和Cr主要来源为交通污染源,也有一部分来自工业污染源;Ni和Be主要来自于混合污染源,即交通污染源和工业污染源;Cd的污染源与其余重金属元素的污染源存在显著的差别,其可能主要来源于合金和建筑材料的腐蚀,电镀的排放,电池和塑料的遗弃,农药和化肥的使用等;交通运输和工业活动也可能向环境中排放少量的Cd。此外,Mn和Co的污染源可能还受到交通污染源和工业污染源的影响。 利用美国环境保护局(EPA)所推荐的健康风险评价方法,对乌鲁木齐城市道路沙尘重金属污染进行了人类健康风险评价(包括非癌症风险评价和癌症风险评价)。结果表明,Cd、Cr、Cu、Ni、Pb、Mn、Be、Co、Zn和U的非癌症综合健康风险指数分别为1.10E-03、1.98E-02、2.23E-03、2.23E-03、1.48E-02、8.80E-03、2.05E-03、3.45E-02、9.27E-04和3.34E-03。10种重金属的综合健康风险指数均小于1,属于安全水平;Cd、Cr、Ni、Co和Be的致癌风险值分别为5.03E-10、1.56E-07、2.49E-09、7.35E-09和1.58E-09,均在10-4-10-6之间,属于可接受的范围,因此,乌鲁木齐市的道路沙尘重金属污染的癌症健康风险并不明显。A total of 169 road dust samples collected in August 2007 in the city of Urumqi, capital of the Xinjiang Uygur Autonomous Region in northwest China, were analyzed by using method of Inductively Coupled Plasma–Mass Spectrometry (ICP–MS) for ten heavy metals (i.e. Cd, Cr, Cu, Ni, Pb, Mn, Be, Co, Zn and U). The results indicate that the mean concentrations of Cd, Cr, Cu, Ni, Pb, Mn, Be, Co, Zn and U of all samples were 1.17, 54.28, 94.54, 43.28, 53.53, 926.60, 2.75, 10.97, 294.47 and 2.13 mg/kg, respectively. Except for Co and U, the mean concentrations of eight metal pollutants were larger than their background values. Based on contamination assessment of the metals, it can be found that almost all of the urban area was polluted slightly with the integrated pollution index (IPI) larger than 1. Moreover, some areas were moderate pollution with the integrated pollution index between 2 and 3. The pollution sources of the ten metals were identified by using multivariate analysis methods, such as correlation analysis, principal component analysis (PCA) and cluster analysis (CA), combined with enrichment factor (EF). The results indicate that the mean EFs of metal pollutants decrease in the following order: Cd > Zn > Cu > Pb > Be > Ni > Mn > Cr > Co. The lowest mean EF value is found for Co, implying a significant contribution of natural sources. The mean EFs of Cr, Ni, Mn and Be range between 1 and 3, while those of Cd, Cu, Pb and Zn are higher than 3, implying a significant contribution of anthropogenic sources. The sources of Mn, Co and U are mainly of natural source; Cu, Pb, Zn and Cr originate mainly from traffic source and partly from industrial source; Ni and Be can be attributed to industrial activities and traffic source, while the sources of Cd are obviously different from those of other metal pollutants considered in this study. Corrosion of alloy and building materials, galvanization, batteries and plastic may be the major sources of Cd. Traffic and industrial activities can also produce Cd. Moreover, the sources of Mn and Co are of traffic and industrial sources. The human health risk (noncancer risk and cancer risk) induced by heavy metals in road dusts was assessed based on the model developed by the US Environmental Protection Agency (US EPA). The results indicate that the hazard index of non-cancer risk of Cd, Cr, Cu, Ni, Pb, Mn, Be, Co, Zn and U was 1.10E-03, 1.98E-02, 2.23E-03, 2.23E-03, 1.48E-02, 8.80E-03, 2.05E-03, 3.45E-02, 9.27E-04 and 3.34E-03, respectively. The hazard indices of all the ten metals are lower than 1, reflecting a safe level. The level of cancer risk of Cd, Cr, Ni, Co and Be was 5.03E-10, 1.56E-07, 2.49E-09, 7.35E-09 and 1.58E-09, respectively. The level of cancer risk is acceptable.
学科主题城市地理 ; 环境污染及其防治
公开日期2010-11-12
页码共91页
内容类型学位论文
源URL[http://ir.xjlas.org/handle/365004/8468]  
专题新疆生态与地理研究所_中国科学院新疆生态与地理研究所(2010年以前数据)
推荐引用方式
GB/T 7714
韦炳干. 乌鲁木齐城市道路沙尘重金属污染空间分布特征及其健康风险评价[D]. 北京. 中国科学院.新疆生态与地理研究所. 2009.
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