中文摘要：

城市街道灰尘是反映城市环境污染状况的重要指标之一。以咸阳市区为研究地点,在咸阳市交通十字路口采集街道灰尘样品,采用原子吸收光谱仪测定街道灰尘中的Pb、Cd、Cu含量,研究咸阳市街道灰尘重金属的污染含量水平和空间分布特征。采用潜在生态危害指数法对样品中重金属的潜在生态危害进行了评价。结果表明：咸阳市街道灰尘重金属大多数地方超过了陕西省土壤背景值,Cu污染浓度多处于1~5.8倍背景值水平;Cd大多处于0~1.7倍背景值水平;Pb大部分处在0~2.6倍背景值水平。就单个重金属潜在生态危害系数平均值来看,街道灰尘的潜在生态危害最大的是Cd,Cu的生态危害次之,生态危害最低的是Pb。总体来讲,咸阳市街道灰尘的生态危害水平属于轻生态危害。

英文摘要：

Urban street dust is one of the important indicators that reflects status of urban environmental pollution. The dust samples were collected in the district of traffic crossroads in Xianyang city. The experiment used atomic absorption spectrometry to measure lead, cadmium and copper of the dust content. Spatial technique was applied to study the content level and the spatial distribution character of heavy metal pollution in street surface dust of Xianyang city. Geochemical maps of heavy metals （Cd, Cu, Pb）in the street surface dust were produced based on and adopting Hakanson suggested potential ecological risk index technique to assess the potential ecological risk of heavy metals in street surface dust, and utilizing geographical information system （GIS） technique to draw up the spatial distribution map of assessment results. The results showed that the majority of heavy metals in the dust exceeded the soil background value in Xianyang city streets. The range of Cd, Cu and Pb contents in street dust is 0.09-0.2mg·kg^-1, 68.82-1212.58 mg·kg^-1 and 23.44-97.63mg·kg^-1, respectively. Cu is 1-5.8 times of the soil background value in Xianyang. The contents of Cd and Pb are 0-1.7 and 0-2.6 times of the soil background value in Xianyang. Based on the calculation results of heavy metal ecological risk indexs in street surface dust of Xianyang, potential ecological risk of Cd is the highest, Cu is moderate and Pb is the least. The ecological hazard for the different domains was in the order of industrial area 〉 school area 〉 business area 〉 agriculture area. Generally speaking, heavy metals pollution in urban street dust of Xianyang reached the lightly ecological risk levels. The results are expected to provide important scientific basis for the urban environmental poIlution control and city planning of Xianyang.