中文摘要：

为揭示银川平原及周边地区表层土壤中多环芳烃分布特征，分析了银川平原及周边地区37个表层土壤样品中16种美国环保署优先控制多环芳烃的含量与组成特征。结果表明，研究区域内表层土壤中多环芳烃含量为17．2～1199．3ng·g^-1（干重）之间，算数均值为190．6±232．2ng·g^-1，几何均值为125．9ng·g^-1，与国内外相关研究相比处于较低水平。多环芳烃以三环和二环为主要组分，荧蒽与菲为主要污染物，主要来源为区域内的燃烧源排放。多环芳烃在研究区域内呈南北高、东西低的分布态势，人类生产、生活排放和土壤中有机质对多环芳烃的吸附性是影响其空间分布的重要因素。耕地中多环芳烃含量高于草地与荒地，接近我国东部地区耕地，且受土壤总有机碳影响，高环组分所占丰度高于草地和荒地。

英文摘要：

The emissions of polycyclic aromatic hydrocarbons （PAHs） can result in contamination of soils and agricultural products. In this study, 37 surface soil samples were collected from Yinchuan Plain and the surrounding areas. Sixteen US EPA priority pollutant PAHs were measured individually to address their geographical distribution pattern in soils. The total concentrations of the 16 PAHs varied from 17.2 to 1 199.3 ng.g-1 with arithmetic and geometrical means of 190.6±232.2 ng·g^-1 and 125.9 ng·g^-1 respectively, which were generally lower than those reported for other areas. The dominant PAHs were two or three ring compounds, typica!ly anthracene and phenanthrene. The isomer based source apportionment suggested that the PAHs were primarily originated from combustion. Uneven spatial distribution was observed with relatively high concentrations found in the north and south areas and relatively low in the east and west ones. The spatial distribution pattern of PAHs was associated with that of emission sources and soil total organic carbon （TOC）. The concentrations of PAHs in crop- land soils were much higher than those in grassland and sparsely-vegetated land soils, likely due to high TOC contents in the cropland soils,