珠江口水域鱼虾类重金属残留的调查

Residues of heavy metals in economic aquatic animal muscles in Pearl River estuary,south China

于 2 0 0 0年 5～ 6月、10～ 11月对珠江口区 4个入海口 (虎门、蕉门、横门和磨刀门 )进行取样调查 ,10个采样点共采得鱼虾类样品 2 4种 ,分属 2 1科。进行Cu、Zn、Pb、Cd、Ni、As、Cr的肌肉残留分析 ,并与 1986年和 1999年调查结果进行比较。结果表明 ,2 0 0 0年珠江口生物体主要残留物为As、Cd、Pb ,其污染负荷比分别为 36 .8%、2 5 .6 %和 19.8% ;Cu和Cd检出率最高 ,皆为 10 0 % ;As、Cd超标率最高 ,分别为 2 3.2 %和 16 .9%。方差分析显示 ,丰水期 (5～ 6月 )与枯水期 (10～ 11月 )Zn、As、Cr、Ni的平均残留量差异显著 ;对于不同生活水层和不同食性的鱼类 ,Cu的平均残留量差异极显著 ,呈底层 >中下层 >中上层 ,而其他 6种元素无显著差异。鱼、虾肌肉重金属污染综合指数均值为 0 .4 3。

An investigation was conducted in May,June,October and November 2000 to determine the residues of Cu,Zn,Pb,Cd,Ni,As and Cr in aquatic animal muscles in Pearl River estuary. From four entrances in the estuary,called Humen,Jiaomen,Hengmen and Modaomen,24 species of fishes and shrimps,belonging to 21 families,were collected. The analysis results show that the main residues in the animal muscles are As,Cd and Pb with the pollution duty ratios of 36.8%,25.6% and 19.8%,respectively. Cu and Cd have the highest detectable ratios,both 100%; As and Cd have the highest standard exceeding ratios of 23.2% and 16.9%,respectively. By variance analysis,the residues of Zn,As,Cr and Ni have significant differences between rainy season( May June) and dry season (October November) ; for the animals living at different water layers and feeding different diets, Cu residues have extremely significant difference,whereas the other six elements do not. The average synthetical pollution index of the seven elements in fishes and shrimps is 0.43,implicating the pollution degree is not high.