珠江口沉积物的重金属背景值及污染评价分区

应用沉积背景海区划分结合数理统计方法估算出了珠江口沉积物中的重金属背景值,然后使用这些背景值通过潜在生态危害指数法对珠江口表层沉积物中的重金属进行了污染评价与分区。珠江口沉积物中Cu、Zn、Pb、Cr、As、Cd和Hg背景值(μg/g)分别为38.6、100.7、44.0、81.1、22.9、0.20和0.170。评价结果表明珠江口表层沉积物中重金属总体污染程度以中等为主,而总体潜在生态危害则以低等级占优。洪奇门、横门口向东南延伸至万顷沙南部海域重金属总体污染程度和潜在生态危害等级均为重,该区域Cd和Hg的污染需要重点关注。

Background Values,Contamination Assessment and Zoning of Heavy Metals in Sediments of the Pearl River Estuary

Background values of heavy metals in sediments at the Pear river estuary were estimated through division of background sedimentation zones in combination with statistical methods,then the contamination of heavy metals in surface sediments at the Pear river estuary was assessed and zoned in terms of these background values through potential ecological risk indexing. The background values (μg/g) of Cu,Zn,Pb,Cr,As,Cd and Hg are 38.6,100.7,44.0,81.1,22.9,0.20 and 0.170,respectively. Assessment results revealed that the degree of total heavy metal contamination in surface sediments at the Pear River estuary is mainly moderate; the degree of total potential ecological risk is light for most of the study area. However,the degree of total heavy metal contamination and potential ecological risk is heavy for the entrance of Hongqimen,Hengmen and the sea area extends southeastward to the south of Wanqinsha,in which the sediment contamination of Cd and Hg requires special concern.