中文摘要：

于2011年12月-2012年11月,在重庆主城区设置了3个采样点,利用湿沉降自动采样器收集降水样品,用ICP-MS对样品中13种重金属进行分析,并通过引入富集因子,研究了重庆主城区降水中重金属含量分布特征、污染水平及沉降量.结果表明,重庆主城区降水中大部分重金属元素的含量水平和年沉降量高于国内其他城市和国外一些地区,其中,Cd、Pb、As含量和沉降量分别为0.55μg·L^-1和0.44 mg·（ m^2·a）^- 1、37.94μg·L-1和30.25 mg·（ m^2·a）^- 1、5.65μg·L-1和4.50mg·（ m^2·a）^- 1,相对较高.另外,重庆主城区降水中重金属含量和沉降量空间差异不大,但都有明显的季节差异,含量在秋季和冬季出现较大值,而沉降量在春季和夏季出现较大值.富集因子计算结果显示,多种重金属元素的富集因子相对较高,其中Cd和Se的富集因子分别为1 740和4 133,污染较为严重.

英文摘要：

Concentrations and deposition fluxes of heavy metals in the precipitation of core urban areas of Chongqing were investigated for one year from December 2011 to November 2012. Precipitation samples were collected with an automated precipitation sampler from three sampling sites. Concentrations of 13 heavy metals were analyzed using ICP-MS. Results showed that the concentrations and annual deposition fluxes of most elements in precipitation were higher than those in other domestic cities and regions overseas. For instance,the concentrations of Cd,Pb and As at the three sampling sites were up to 0. 55 μg·L^- 1,37.94 μg·L^- 1and 5. 65 μg·L^- 1respectively,and annual deposition fluxes of Cd,Pb and As reached 0. 44 mg·（ m^2·a）^- 1,30.25 mg·（ m^2·a）^- 1,and 4.50mg·（ m^2·a）^- 1respectively. In addition,there were no obviously spatial differences for concentrations and deposition fluxes of heavy metals in urban Chongqing,but significantly seasonal variations were found. Maximum concentrations occurred in autumn and winter,while the highest deposition fluxes appeared in spring and summer. Moreover,the enrichment factor（ EF） was employed to estimate the pollution level of heavy metals. Results showed that EFs of Cu,Pb,Zn,Cd,Ag,As and Se were over 100,suggesting that these metals in atmosphere were seriously influenced by human activities,especially for Cd and Se,the EFs of which were 1 740 and 4 133respectively.