北极8种典型痕量金属及3种铂系贵金属浓度水平变化趋势及生态风险

TEMPORAL TRENDS AND ECOLOGICAL RISKS OF EIGHT TYPICAL TRACE METALS AND THREE PLATINUM GROUP METALS IN THE ARCTIC

痕量金属进入北极的途径包括洋流注入、大气传输、陆架河流、陆地径流以及海洋中的直接沉降。研究表明,北极区域介质中Pb、Hg与Cd、Zn、Cu水平随着工业化的发展呈现出不同的变化趋势,并且铂系贵金属在北极冰雪中被检测出反映了大范围的全球污染。对北极各海域表层沉积物中的痕量金属As、Cd、Cr、Cu、Hg、Pb、Zn进行生态风险评价发现:As、Cd、Cu很有可能已经对多数海域的海洋生物产生威胁;Hg、甲基汞(MeHg)、Zn在极地动物器官中已出现了食物链累积效应,相关的毒性数据目前还缺乏研究。

The pathway for trace metals entering the Arctic region includes ocean input, atmospheric transportation, river input, land runoff, and atmospheric deposition. This study analyzed the temporal trends of several trace metals in a variety of environmental media from the Arctic region. Among these trace metals, eight typical trace metals （As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn） have been the focus of previous environmental monitoring. However, mining and smelting activities and the application of automobile catalysts have led to platinum group metals （including Pt, Pd, and Rh） potentially becoming serious pollutants. The results of this study showed that Pb and Hg, attributable to industrial development, present variation trends distinct from Cd, Zn, and Cu in the environmental media, and that Pt, Pd, and Rh concentrations evidence global pollution resulting from large-scale transportation from areas of human activity. The potential risks associated with As, Cd, Cr, Cu, Hg, Pb, and Zn are also assessed based on previously published scientific data on the levels of trace metals in surface sediments from areas within the Arctic Sea. It is concluded that concentrations of As, Cd, and Cu in the sediments across a large part of the Arctic Sea probably pose a threat to marine organisms. Concentrations of Hg, MeHg, and Zn in the organs of Arctic animals have been reported to be accumulating with trophic level, and this evidence of definite toxicity requires further study.