重金属在北江鱼类和底栖动物体内的富集及污染评价

调查研究了北江中上游的鱼类、虾、螺和蚬,以及鲤鱼体内不同组织中重金属Pb、Cd、Hg、As的含量,并采用污染指数法对重金属的污染进行了评价。调查结果显示,不同水生动物体对同种重金属元素的富集量存在较大差异,而同一水生动物体对不同重金属元素的富集能力也有很大区别。北江鱼体肌肉中不同重金属的污染程度由强至弱的顺序为:CdPbHgAs;不同水生动物体的可食部分重金属综合污染水平由高至低依次为:蚬螺虾鱼。鱼体中不同器官组织对重金属的蓄积能力差异巨大,北江鲤鱼体内各器官组织蓄积重金属总量依次为:内脏鳃脂肪肌肉。该次调查采集的北江底栖类动物样品已明显受到重金属污染,达不到无公害水产品安全要求;而北江鱼类肌肉则满足无公害水产品安全要求。

Heavy Metal Enrichment in Aquatic Organisms of Beijiang River:Its Characteristics and Pollution Evaluation

An investigation was carried out to study the status quo of heavy metals including Pb, Cd, Hg and As enrichment in different aquatic organisms living in the Beijiang River, such as fish, shrimps, spiral shells and clam shells as well as different parts of Cyprinus carpio. Pollution index methodology was employed to evaluate the heavy metal pollution level, and results indicated that degree of the heavy metals enriched in fish muscles ranks as Cd>Pb>Hg>As;pollution degree in edible parts of the study organisms due to the heavy metals as clam shells> spiral shells> shrimps>fish;and the descending order of the heavy metals amount accumulated in different parts of Cyprinus carpio as viscera>gill>fat>muscle. According to the survey it can be concluded that benthos of the River have been severely contaminated by heavy metals and are not edible;however, fish in terms of muscles are still in compliance with the safety requirements for non-environmental pollution aquatic products stipulated by the relevant government department.