中文摘要：

为有效制定城市扬尘的防治措施，系统研究宁波城市扬尘污染的化学组成特征和来源，选取宁波为研究区域，采集了城市扬尘、土壤风沙尘、煤烟尘和机动车尾气尘4种源类样品，进行了元素、离子和碳3大类分析，并与其他城市进行了比较。结果表明：（1）宁波城市扬尘的主量成分包括Ca、Si、Fe、Al、K、总碳（TC）、有机碳（0C）和SO24-，质量分数总和为44．14％，其中Ca、Si、Fe、Al、K等地壳元素含量较高。宁波城市扬尘化学组成与其他典型城市相差较大，其中Si、Al和Mg含量明显低于其他城市，而Na、K、Ni等元素含量总体较高。（2）分歧系数计算结果为0．471，说明城市扬尘与土壤风沙尘的化学组成相似度不高，受人为来源类的影响较大。（3）宁波的城市扬尘中Zn富集因子最大，达23．10，其次为Ca、Cu、Pb、Ni、As，且这些重金属元素的富集因子均在5之上，表明Zn、Ca、Cu、Pb、Ni、As显著富集，受人类活动影响较大。（4）土壤风沙尘对城市扬尘的贡献最大（分担率达34．88％），其次为建筑水泥尘（分担率达25．01％）、煤烟尘（分担率达20．19％）。说明城市扬尘中大部分化学组分来自土壤风沙尘、建筑水泥尘和煤烟尘。

英文摘要：

In order to provide a basis for re-suspended dust （RD） control and make clear of the chemical compo- sitions and sources of RD in Ningbo,samples of particulate sources including re-suspended dust （RD）, soil dust, coal combust fly ash and vehicle exhaust dust were collected at the atmospheric monitoring state-controlled points of Ning bo. Elements,ions and carbon in particulate sources samples were analyzed,and the detection results was compared with other five cities. Results showed that the main components in RD of Ningbo were Ca, Si, Fe, Al, K, TC, OC and SO24- , they contributed 44.14% of total mass of RD. Among these main components,the content of earth crust （Ca, Si,Fe,Al and K） was relative high. The chemical species compositions of RD in Ningbo was significantly different with that in other cities. The content of Si, Al, Mg in RD of Ningbo was much lower compared to other cities, while content of Na,K and Ni was relative high. The value of coefficient of divergence was 0. 471 （〉0.2）,indicated that there were differences between sources profiles of RD and soil dust. Moreover,Zn had the highest the enrichment fac- tor of 23.10,which was followed by Ca, Cu,Pb, Ni and As, their enrichment factors all greater than 5, indicated that they were apparently enriched. Both methods showed that RD was affected by human activities. Chemical mass balance （CMB） analysis showed that the major contributions of RD were soil dust （34.88 % ）, cement dust （25.01%） and coal combust fly ash （20.19%）.