【摘要】 <正> 随着工业生产的不断发展,铅的使用量日益增加,由此铅对环境污染亦日趋严重。据研究,长江向东海排放铅的通量为0.072公斤/秒（其中溶解相为0.008公斤/秒,颗粒相为0.064公斤/秒）,每年排放总量可达二千二百吨之多。铅的放射性同位铅-210(下称²¹⁰Pb),可作为很好的示踪剂来研究海洋环境中铅的地球化学行为,因而被人们所重视。另外,²¹⁰Pb有较为合适的半衰期（22.3年）,因此成为研究近百年来海洋现代沉积作用过程及现代环境污染的重要工具。更多还原

【Abstract】 Pb-210 atmospheric flux of 2.06dpm/cm2 year has been determined by means of measuring the soil sample from the area near the East China Sea continental shelf. The result agrees with the value predicted from the model.After the Pb-210 activities in the sediments have been determined from more than twenty columns in the estuary of the Changjiang River and its adjacent shelf, it is found that both virtical and horizontal distibutions of Pb-210 follow certain laws.The virtical distribution of Pb-210 in the estuary of the Changjiang River and its adjacent shelf can be divided into two types and six forms. The normal type consists of three-region,two region and one regin forms, and the abnormal type consists of parallel, upside-down and disorder forms.The normal virtical distribution of Pb -210 reflects the enviromental condition of steady-sate deposits and from the gradient of Pb-210 profile, the sedimentary accumulation can be calculated.The abnormal vertical distribution of Pb-210 reflects the enviromental condition of unsteady-state deposits, some sudden events,such as resuspension, reworking and sliding, may take place in this area.The horizontal distribution of Pb-210 in the estuary of the Changjiang River and its adjacent shelf is quite different. Pb-210 activities of the surf ace layer in the inner-shelf mud deposit are almost two times smaller than those of the offshore mud deposit and relict sand area. The sedimentary accumulation is the main controlling factor to the Pb-210 distribution. There is a negative relationship between the sedimentary accumulation and horizontal distribution of Pb-210, and a positive relationship between the sedimentary accumulation and virtical depth of Pb-210 in sediments as well as the total Pb-210 radioactive quantity.The total Pb-210 radioactive quantity in the inner-shelf mud deposit area is as high as 160dpm/cm2, much higher than the predicted value of 60dpm/cm2, while the value of the offshore mud deposit and relict sand area is 30dpm/cm2 approximately, much less than the predicted one. The Pb-210 deposit flux in the inner-shelf mud deposit area is four times greater than the predicted one, whereas in the offshore mud deposit and relict sand area is only 60% of the value predicted, From the facts described above, it can be seen obviously that the Pb-210 has been intensely focused in the inner-shelf mud deposit area, but in the offshore mud deposit and relict sand area, the Pb-210 has been largely dispersed. Based upon these geochemistry characteristics of Pb-210, it can be predicted that most of the lead pollutants carried by the Changjiang River are scavenged in the inner-shelf mud deposit area, only a small part of them is darried into offshore and open sea.更多还原