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2009年4月、8月、11月和12月分别对辽东湾北部海域海水和沉积物中的重金属Pb和Cd进行取样分析,并对分析结果进行评价。结果表明,辽东湾北部海域海水中Pb的季节分布特征为:春季>秋季>冬季>夏季,Cd含量随季节变化差别不大。Pb和Cd的空间分布特征总体为近岸高,离岸低,由近岸向离岸方向递减。辽东湾北部海域水体中Pb污染程度高于Cd,春季调查海域有71.9%的站位Pb含量超出二类海水水质标准值,四个季节Cd的含量均在二类水质标准值范围内。春季和冬季辽东湾北部海域沉积物中Pb的含量均较高,且冬季高于春季,而Cd的季节变化特征亦不明显。沉积物中Cd的污染程度高于Pb,四个季节调查海域沉积物中Pb的含量均未超出一类海洋沉积物质量标准值,属轻微生态危害。而Cd均有部分站位超出一类海洋沉积物质量标准值,大多数超标站位Cd的单项潜在生态危害系数介于40～80之间,属中等生态危害。
In April, August, November and December 2009, samples of heavy metals Pb and Cd in seawater and sediment from the northern part of Liaodong Bay were sampled and analyzed respectively. Results of the analysis were also evaluated. The results showed that the seasonal distribution of Pb in the seawater of the northern part of Liaodong Bay was: spring> autumn> winter> summer, the content of Cd had little difference with the seasons. The spatial distribution characteristics of Pb and Cd are generally high in nearshore and low in offshore, decreasing from nearshore to offshore. The Pb pollution in the waters of the northern part of Liaodong Bay was higher than that of Cd. The content of Pb in 71.9% of stations in the surveyed waters in spring exceeded the standard of Grade II seawater, and the content of Cd in four seasons was within the standard of Grade II water quality. The contents of Pb in the sediments of the northern part of Liaodong Bay in spring and winter were higher than that in spring, but the seasonal variation of Cd was not obvious either. Cd pollution in sediments is higher than that in Pb. The Pb concentrations in the sediments of the four seasons are no more than the standard value of marine sediments, which is a minor ecological risk. However, some stations of Cd are beyond the standard value of a kind of marine sediment, and the potential ecological risk factors of most of the stations exceeding the standard range from 40 to 80, which are intermediate ecological hazards.