| Lots of suspend materials was preserved in the Eastern Chinese Seas, which is also aplace for strong interaction between land and sea. During one hundred years ofindustrialization, especially since the reform and open-up of China, a lot of heavymetals were delivered into the Eastern Chinese Seas by river transportation andatmospheric deposition, at last they were finally preserved in sediment bodies. Thescientific researches on the heavy metals of the sediment bodies not only help usreconstruct the regional pollution history but also help us further understand theimpact of human activities on marine environments of these seas. What’s more, theyprovide valuable information on the “source to sink” of heavy metals in these seasincluding its process and affections.5sediment cores and102surface sediments werecollected in the East China Sea and south Yellow Sea, which were determined byhigh-purity well germanium detector, desktop X-ray fluorescence (XRF) system, laserparticle size analyzer, Inductively Coupled Plasma Mass Spectrometry (ICP-MS) andInductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES), the level ofthe grain size, trace metal, major element and isotope of Pb is obtained, so thecharacter of spatial distribution of elements in study area is found and high-resolutionsedimentary records of heavy metal was built and then discussed the process and effect of source to sink of heavy metal in study area. The outcome of our studydisplay as follow:The concentration of heavy metals of fine-grained sediment in the south Yellow Seaand East China Sea is measured, so spatial distribution of heavy metals in study areawas obtained. They have a similar spatial distribution but they are of significantdifference between the Yellow Sea and East China Sea. Higher concentration of heavymetals is in the inner shelf mud area of the East China Sea, and it decreases graduallyin the southeastern direction in the East China Sea. Besides, the higher concentrationof heavy metals is in the eastern Yellow Sea and it decrease in west direction.The Cu, Cr, Ni and V of surface sediments aren’t contaminated and the Pb and Zn aremoderately contaminated in general, which are indicated by the results of EnrichmentFactor (EF) and Geoaccumulation Index (Igeo). Although Pb and Zn facecontamination in some extent, the study area face very low ecological risk due toheavy metal indicated by potential ecological risk index.The results revealed that heavy metal pollution could be divided into three stages:Stage1, representing the baseline period before the1930s and characterized by lowheavy metal concentrations and enrichment factors (EFs) for Pb and Zn; Stage2,representing the1930s to the early1980s and characterized by significantly higher EFvalues for Pb and Zn compared with the baseline values; and Stage3, extending from 1983to the present, marked by dramatically increasing Pb and Zn levels. Althoughheavy metal concentrations have increased since the1930s, the coastal mud area ofthe ECS remains under low ecological risk.Per unit area of burial flux of Cu, Cr, Ni, V, Pb and Zn was evaluated in my paper andthe spatial distribution of them was also obtained. The higher per unit area of burialflux is in near shore area of the East China Sea and it decrease in the eastern direction(middle and outer shelves). In south Yellow Sea, it of these elements has no obviousvariation. About79to82percent of heavy metal was buried in the East China Sea.Although various anthropogenic sources of heavy metal were inputted into the studyarea, the possible source of lead into the East China Sea is metal smelting, coalcombustion, unleaded gasoline combustion and cement, which were classified byinventory of anthropogenic source. Comparing isotope fraction of Pb in marinesediment of near shore of the East China Sea with that of possible anthropogenicsource, the results suggest that anthropogenic Pb in study area most originated fromthe coal combustion. |
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