万山汞矿区银环蛇重金属生物富集研究

Bio-concentration of Heavy Metals in Bungarus multicinctus in Wanshan Mercury Mining Area

蛇类作为高营养级捕食者,被认为更适合作为环境重金属污染的指示生物。为了解贵州万山汞矿区及周边区域银环蛇(Bungarus multicinctus)重金属元素生物富集特征,文章利用路杀银环蛇个体,对万山汞矿、漾头镇(万山汞矿下游)和梵净山(对照区)银环蛇组织(骨、肌肉和皮肤)中铬(Cr)、锰(Mn)、镍(Ni)、铜(Cu)、锌(Zn)、镉(Cd)、铅(Pb)、砷(As)、硒(Se)和汞(Hg)等10种重金属元素含量和污染特征进行分析,并结合非负矩阵模型识别重金属元素的来源。结果表明:万山汞矿区银环蛇体内Hg、Se和As含量较高,Hg污染严重,其他重金属元素污染风险较低。漾头镇银环蛇重金属污染风险较低,仅受到中等程度的Hg污染。梵净山银环蛇体内Cr、Mn、Cd和Pb含量较高,Cd属严重污染。重金属元素主要富集在银环蛇皮肤中,其次为肌肉组织。皮肤中的绝大部分重金属元素含量与骨和肌肉中的含量显著正相关,皮肤具有较好的生物指示作用。基于非负矩阵模型,银环蛇体内Hg和Se主要源于Hg矿开采活动,Cd、Pb、Mn和Cr主要为自然来源,Zn和Cu主要源于交通运输,Ni和As来源于多种复合途径。研究结果可为汞矿区环境污染防控及野生动物保护提供科学依据。

The snake,as a high trophic level predator,is regarded to be a appropriate biological indicator for evaluating envi-ronmental heavy metal pollution.In this paper,Bungarus multicinctus existing in Wanshan mercury mining area and the surrounding region of Guizhou Province was investigated about the bio-concentration characteristics of heavy metal elements contained in this species of snake.Lab assays were conducted with the samples of dead Bungarus multicinctus(killed by road traffic vehicles)collected from Wanshan mercury mining area,Yangtou township(downstream of the Wanshan mercury mine)and Mount Fanjing(as a control area).The contents of 10 heavy metal elements were analyzed specifically including Cr,Mn,Ni,Cu,Zn,Cd,Pb,As,Se and Hg contained in the tissues of Bungarus multicinctus(bones,muscles and skin),and the heavy metal pollution features in Bungarus multicinctus were studied,furthermore the pollution sources identified by a non-negative matrix model.The results obtained with regard to Wanshan mercury mining area showed the elevated levels of Hg,Se and As in the snakes(Bungarus multicinctus),especially,Hg that had the highest potential pollution risk,while the risks of other heavy metal elements were lesser;as to Yangtou township,the risk of heavy metal pollution was not high,with only moderate levels of Hg in the snakes;and as for Mount Fanjing,it was found the concentrations of Cr,Mn,Cd and Pb in Bungarus multicinctus were rather high,among which,Cd particlarly had led to serious contamination.In addition,heavy met-al elements were primarily enriched in the snakes’skin,next in the muscle tissues,and the results of the pertinent analysis showed that there existed a significantly positive correlationship between the snakes’skin and the tissues of bone and muscle in terms of content of the majority of heavy metal elements,so the skin could play a pretty good role as biological indicator.According to the analysis by use of non-negative matrix model,Hg and Se in Bungarus multicinctus were mainly originated from Hg mining activities,Cd,Pb,Mn and Cr mainly from natural sources,Zn and Cu largely from traffic transport,and Ni and As from multiple composite pathways.It is expected that this research results would provide a scientific basis for the pre-vention and control of environmental pollution in mercury mining areas,as well as for wildlife conservation.