东海海洋大气颗粒物中重金属的来源及入海通量

Source and Air-sea Fluxes of Heavy Metals in the Atmospheric Particles of East China Sea

2006～2007年,对杭州湾以南的东海海域进行了春、夏、秋、冬4个航次的海洋大气调查,分析了大气颗粒物中重金属元素(Cu、Pb、Zn、Cd)的含量,根据调查结果,采用富集系数法对重金属的来源进行了初步分析,对干沉降入海通量进行了估算.结果表明,调查海域海洋大气颗粒物中的Cu、Pb、Zn、Cd含量相对于地壳和海水均表现为强富集,富集系数远远大于10,属于污染元素,主要来自人类活动污染.重金属元素的大气干沉降通量大小顺序为Zn[10.92 mg/(m2.a)]>Pb[2.299mg/(m2.a)]>Cu[1.611 mg/(m2.a)]>Cd[0.017 mg/(m2.a)].各种金属元素月通量均为冬季最高,夏季或秋季最低,且季节差异十分显著.按调查区域覆盖面积(160 000 km2)估算,每年Cu、Pb、Zn、Cd大气干沉降总量为2 376 t,约为长江重金属年入海通量的13%,因此大气输入也是重金属进入东海的重要途径之一.

From 2006 to 2007,four surveys for marine atmosphere in East China Sea were carried out included different seasons（spring,summer,autumn and winter）.Based on the survey data of heavy metals in marine atmospheric particles,analyzed the source of heavy metals by the calculation of Enrichment Factors,calculated the air-sea fluxes via dry deposition.The results showed,comparing with the crustal and seawater,the heavy metals including Cu,Pb,Cd and Zn were highly concentrated,mainly from the pollutants of human activities.The fluxes of heavy metals via dry deposition were Zn[10.92mg/（m2·a）]Pb[2.299mg/（m2·a）]Cu[1.611mg/（m2·a）]Cd[0.017mg/（m2·a）].The fluxes of heavy metals in winter were highest,the summer and autumn were lower.The input of Cu,Pb,Zn and Cd from atmosphere to sea via dry deposition was 2 376 t,nearly 13% compared with the input of The Changjiang River（Yangtze River）.