中文摘要：

在开封市的工业区（ID）、居民区（RD）、文教区（CED）和交通密集区（TD）共采集27个地表灰尘样品,用冷原子荧光法测定样品As、Hg含量,采用地积累指数法（Igeo）和污染负荷指数法（PLI）开展开封城市灰尘污染评价.结果表明,开封市灰尘As、Hg平均含量分别为6.15mg/kg和225.15μg/kg,As含量略低于其背景值,而Hg含量远高于其背景值,城市灰尘组成的复杂性对As含量降低具有重要影响.ID、CED、RD和TD灰尘As平均含量分别为8.33、7.30、4.66和4.10mg/kg,灰尘Hg平均含量分别为162.10、189.77、358.86和143.48μg/kg.几乎所有样点没有发生As污染,而绝大部分样点发生了不同程度的Hg污染.全市灰尘平均PLI为2.28,总体上呈中污染,CED和ID污染较为严重,汞是最主要的污染因子.灰尘中Hg的来源与化石燃料燃烧、工业生产、生活垃圾和文教区各种实验室废物排放等多种因素有关.

英文摘要：

Twenty-seven urban dust samples were collected in industrial district（ID）,residential district（RD）,cultural and educational district（CED）and traffic district（TD）in Kaifeng city,China.Concentrations of As and Hg in the samples were determined with cold vapor atom fluorescence spectrometry（AFS）.Geoaccumulation Index（Igeo）and Pollution Load Index（PLI）were employed to assess dust pollution with As and Hg.The results show that the average concentrations of As and Hg in urban dusts are 6.15 mg/kg and 225.15μg/kg respectively.Concentration of As is lower than its background value under the influence of complex composition of urban dusts,while that of Hg is much higher than its background value.The average concentrations of As in ID,CED,RD and TD dusts are 8.33,7.30,4.66 and 4.10mg/kg respectively,while those of Hg are 162.10,189.77,358.86and143.48μg/kg respectively.Almost all of the samples are not polluted by As,but different levels of pollution occurred for Hg.The average PLIof As and Hg in all sample sites is 2.25 indicating moderate pollution occurred as a whole.CED and ID were seriously polluted mainly attributed to Hg which is the most essential contamination factor.Mercury in dusts are mainly from fossil fuel combustion,industrial activities and laboratory wastes in CED.