Lindeberg Carola, Bindler Richard, Renberg Ingemar, Emteryd Ove, Karlsson Edvard, Anderson N John
Environmental Change Assessment, Department of Ecology and Environmental Science, Umeå University, SE-901 87 Umeå, Sweden.
Environ Sci Technol. 2006 Jan 1;40(1):90-5. doi: 10.1021/es051223y.
Given the current scenario of increasing global temperatures, it is valuable to assess the potential influence of changing climate on pollution distribution and deposition. In this study we use long-term sediment records from three lakes (spanning ca. 1000, 4800, and 8000 years, respectively) from the Greenland west coast to assess recent and long-term variations in mercury (Hg) and lead (Pb), including stable Pb isotopes (206Pb and 207Pb), in terms of pollution and climate influences. The temporal trends in sediment deposited from about the mid-19th century and forward are in general agreement with the history of industrial emissions at lower latitudes. Therefore, in recent sediment a possible influence from changing climate is difficult to assess. However, by using deeper sediment layers we show that changes in Greenland climate caused changes in the lake influx of material from regional aeolian activity, which resulted in large fluctuations in Hg and Pb concentrations and 206Pb/207Pb ratios. The aeolian material is primarily derived from glacio-fluvial material with low Hg and Pb concentrations and a different isotopic composition. For one of the lakes, the fluctuations in Hg concentrations (10 to 70 ng g(-1)) prior to the 19th century are equal to the anthropogenic increase in the uppermost layers, suggesting that when studying recent concentrations and time trends of pollution in relatively low-contaminated areas such as the Arctic, the early natural fluctuations must be considered.
鉴于当前全球气温上升的情况，评估气候变化对污染物分布和沉降的潜在影响具有重要意义。在本研究中，我们利用格陵兰岛西海岸三个湖泊（分别跨越约1000年、4800年和8000年）的长期沉积物记录，从污染和气候影响方面评估汞（Hg）和铅（Pb），包括稳定铅同位素（206Pb和207Pb）的近期和长期变化。从大约19世纪中叶及以后沉积的沉积物中的时间趋势总体上与低纬度地区的工业排放历史一致。因此，在近期沉积物中，气候变化的可能影响难以评估。然而，通过使用更深的沉积层，我们表明格陵兰岛气候的变化导致了区域风成活动向湖泊输入物质的变化，从而导致汞和铅浓度以及206Pb/207Pb比值大幅波动。风成物质主要来源于汞和铅浓度较低且同位素组成不同的冰川河流物质。对于其中一个湖泊，19世纪之前汞浓度的波动（10至70 ng g(-1)）与最上层的人为增加量相当，这表明在研究北极等污染相对较低地区近期的污染浓度和时间趋势时，必须考虑早期的自然波动。
