Universite Grenoble Alpes, CNRS, IRD, IGE, 38000 Grenoble, France; CIEMAT - Environmental Department (DMA), Avenida Complutense 40, E-28040 Madrid, Spain.
CIEMAT - Environmental Department (DMA), Avenida Complutense 40, E-28040 Madrid, Spain.
Sci Total Environ. 2021 Jan 10;751:141557. doi: 10.1016/j.scitotenv.2020.141557. Epub 2020 Aug 14.
We have analyzed potential harmful trace elements (PHTE; Pb, Hg, Zn, As and Cu) on sediment cores retrieved from lake Marboré (LM) (2612 m a.s.l, 42°41'N; 0° 2'E). PHTE variability allowed us to reconstruct the timing and magnitude of trace metal pollutants fluxes over the last 3000 years in the Central Pyrenees. A statistical treatment of the dataset (PCA) enabled us to discern the depositional processes of PHTE, that reach the lake via direct atmospheric deposition. Indeed, the location of LM above the atmospheric boundary layer makes this lake an exceptional site to record the long-range transport of atmospheric pollutants in the free troposphere. Air masses back-trajectories analyses enabled us to understand the transport pathways of atmospheric pollutants while lead isotopic analyses contributed to evaluate the source areas of metal pollution in SW Europe during the Late Holocene. PHTE variability, shows a clear agreement with the main exploitation phases of metal resources in Southern Europe during the Pre-Industrial Period. We observed an abrupt lead enrichment from 20 to 375 yrs CE mostly associated to silver and lead mining and smelting practices in Southern Iberia during the Roman Empire. This geochemical data suggests that regional atmospheric metal pollution during the Roman times rivalled the Industrial Period. PHTE also increased during the High and Late Middle Ages (10-15 centuries) associated to a reactivation of mining and metallurgy activities in high altitude Pyrenean mining sites during climate amelioration phases. Atmospheric mercury deposition in the Lake Marboré record mostly reflects global emissions, particularly from Almadén mines (central Spain) and slightly fluctuates during the last three millennia with a significant increase during the last five centuries. Our findings reveal a strong mining-related pollution legacy in alpine lakes and watersheds that needs to be considered in management plans for mountain ecosystems as global warming and human pressure effects may contribute to their future degradation.
我们分析了取自马里博雷湖（LM）（海拔 2612 米，北纬 42°41'，东经 0°2'E）岩芯中的潜在有害痕量元素（PHTE；Pb、Hg、Zn、As 和 Cu）。PHTE 的变化使我们能够在过去 3000 年中重建中比利牛斯山脉 trace 金属污染物通量的时间和幅度。对数据集的统计处理（PCA）使我们能够辨别 PHTE 的沉积过程，这些过程通过直接大气沉积到达湖泊。事实上，LM 的位置高于大气边界层，使该湖成为记录自由对流层大气污染物长程传输的特殊地点。空气团后向轨迹分析使我们能够了解大气污染物的传输途径，而铅同位素分析有助于评估全新世晚期欧洲西南部金属污染的源区。PHTE 的变化与前工业化时期南欧金属资源的主要开采阶段明显一致。我们观察到从 20 到 375 年 CE 的铅突然富集，主要与罗马帝国时期伊比利亚南部的银和铅矿开采和冶炼有关。这些地球化学数据表明，罗马时期的区域大气金属污染与工业时期相当。PHTE 也在中世纪后期（10-15 世纪）增加，与气候改善阶段高海拔比利牛斯山矿场采矿和冶金活动的重新活跃有关。马里博雷湖记录中的大气汞沉积主要反映了全球排放，特别是来自西班牙中部阿尔马登矿的排放，在过去三千年中略有波动，在过去五百年中显著增加。我们的发现揭示了高山湖泊和流域中与采矿有关的强烈污染遗留问题，在考虑山区生态系统的管理计划时需要考虑到这一点，因为全球变暖与人类压力的影响可能会导致它们未来的退化。
