Sediment heavy metal record in Lake Baikal: natural and antrhopogenic sources
Sediment heavy metal record in Lake Baikal: natural and antrhopogenic sources
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贝加尔湖沉积物重金属记录：自然和人为来源
DOI：
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
P. Appleby
中科院分区：
文献类型：
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作者：
J. Boyle;A. Mackay;N. Rose;R. Flower;P. Appleby
对贝加尔湖近期沉积物的6个放射性测年短岩心进行的地球化学分析表明，铅的供应得到了增强。然而，泥沙浓度增加很小，平均铅浓度从基线的10.9μg g-1上升到峰值仅14.8μg g-1。与欧洲和北美普遍研究的污染较严重的湖泊不同，铅浓度的变化受自然变化的影响远远大于污染。在过去150-200年间沉积的沉积物中，沉积物中铅含量变化的73%可由沉积物总体组成的变化和大气污染来解释。在这段时间内，影响铅浓度的因素依次为：平均重要性(解释总方差的比例)、集水区供应量(以226Ra活度变化表示)(43%)、人为铅排放(24%)和氢氧化铁稀释(6%)。在更长的时间尺度上(1000年)，生物二氧化硅的稀释可能更重要。最近集水区铅供应的增加与累积速率的加快相关，表明与加剧的侵蚀有关。人为来源仅在当地化石燃料燃烧工业所在的南部盆地占主导地位。铅的库存与球形碳质颗粒之间的高度相关性，加强了铅污染来自当地工业来源的证据。湖泊北部没有可检测到的人为铅富集，表明远距离铅污染与当地自然供给相比较小。
Geochemical analysis of six radiometrically dated short cores of recent sediment from Lake Baikal shows clear evidence of enhanced Pb supply. However, the sediment concentration increases are very small; the average Pb concentration rises from a baseline value of 10.9 μg g-1 to a peak value of only 14.8 μg g-1. In contrast to the more polluted lakes commonly studied in Europe and North America, variation in Pb concentration is far more strongly influenced by natural variation than by pollution. In sediment deposited over the last 150–200 years 73% of the variance in the sediment Pb concentration can be accounted for by variation in bulk composition of the sediment, and by atmospheric pollution. Factors influencing Pb concentrations over this time period are, in order of decreasing average importance (fraction of total variance explained), catchment supply (indicated by 226Ra activity variation) (43%), anthropogenic Pb emissions (24%), and dilution by ferromanganese hydroxides (6%). On longer (1000s of years) time scales dilution by biogenic silica is probably more important.The recent enhanced supply of catchment Pb correlates with accelerating accumulation rates, indicating a link with enhanced erosion. Anthropogenic sources dominate only in the southern basin, where local fossil-fuel burning industry is situated. The evidence for a local industrial source for the Pb pollution is strengthened by the high correlation between the inventories for Pb and for spheroidal carbonaceous particles. The absence of detectable anthropogenic Pb enrichment in the northern part of the lake suggests that long-distance Pb pollution is small compared with the local natural supply.