重庆市汞污染的观测研究

为研究重庆市区汞污染状况，2004年9~11月，同步观测了重庆市近郊铁山坪小流域（TSP）和观音桥(GYQ)两个区域的全沉降、穿透水、地表径流和土壤中的总汞含量，估算了小流域中汞的输入输出通量，分析了城区和郊区的大气汞沉降和分布特征。结果表明，重庆已在一定程度上受到汞污染。在TSP，湿沉降是汞输入的主要方式，也就是说，在TSP，细颗粒是大气汞的主要来源，表层土则是大气汞的一个主要的汇。GYQ区域的汞污染比TSP相对严重。在GYQ，除了湿沉降以外，干沉降是汞来源的重要形式，表明在GYQ，粗颗粒可能对大气汞有很大的贡献。因此，本地源的排放对城区的影响比对郊区的影响大，尤其是城区火电站附近的土壤样品比郊区土壤的汞含量高很多，说明火电站是大气汞的重要来源之一。

CONCENTRATION AND FLUXES OF TOTAL MERCURY AT A FOREST CATCHMENT AND AN URBAN AREA IN CHONGQING CITY

This paper aimed to examine the condition of mercury pollution in Chongqing City.Mercury fluxes were calculated for throughfall,bulk deposition and runoff at two areas: a small forest catchment at Tieshanping(TSP) and an urban area Guanyinqiao(GYQ).The balance of input and output were calculated while the characters of mercury deposition in urban and rural area were analyzed.The results show that the Chongqing Area has endured mercury pollution to some extent,and GYQ endures more dry deposition with an important role at GYQ besides wet deposition,and wet deposition being much more crucial at TSP.In other words,the fine particle in atmosphere is the main source at TSP,and the coarse particles devote a lot at GYQ besides fine particle.So the emissions of local sources have more effects in urban area than in rural area in Chongqing City.Soil,especially the topsoil,is an important pool(reservoir) of mercury in the TSP catchment.Concentrations of mercury in the urban soil samples,particularly the samples near the fire plant,are higher than those in the rural soils,which shows the fire plant is an important mercury source.