Key Laboratory of Plateau Geographic Processes and Environmental Change, School of Tourism and Geography, Yunnan Normal University, Kunming, Yunnan, 650500, China.
Environ Sci Pollut Res Int. 2018 May;25(13):13035-13047. doi: 10.1007/s11356-018-1537-x. Epub 2018 Feb 26.
It has been well established that regional patterns of atmosphere-borne polycyclic aromatic hydrocarbons (PAHs) and trace metals were predominantly associated with the trajectory of socio-economic development; however, they could be potentially modulated by anthropogenic fingerprint of local sources such as industrial spill. Here, we established historical pollution data of both PAHs and trace metals from a well-dated sediment core from Yangzong Lake of Southwest China, which experienced a severe tailing leakage accident derived from a zinc concentrate smelting plant in 2007, aiming to evaluate the heterogeneity in their temporal trajectories and their sources of contamination in the context of regional deposition patterns. Sedimentary records show that the concentrations and fluxes of both PAHs and trace metals remained a consistently low level before the 1950s. An increasing trend and the synchronous changes of both PAHs and trace metals during ~ 1950-2002 were well consistent with the temporal pattern of socio-economic development in western China, with coal combustion and smelting industries as the main sources of contamination in this region. However, arsenic (As) and PAHs exhibited a concurrent spike for the period of ~ 2007-2013, contrasting strongly to the regional pattern of these contaminants. The modern concentrations of As revealed a 5- to 14-fold increase over the pre-1950 level, with the contemporary concentrations of PAHs rising by ~ 10-14 times. The sediment records reveal that local fingerprints of smelting activities in the catchment of Yangzong Lake have overridden the temporary pattern of regional atmosphere-borne As and PAHs over the last decade. This highlights the important role of local pollution sources in modulating or even overriding the regional pattern of anthropogenic contamination in highly impacted systems.
已有充分证据表明，大气中多环芳烃（PAHs）和痕量金属的区域性分布模式主要与社会经济发展轨迹相关；然而，它们可能会受到当地人为污染源的影响，如工业溢出物。在这里，我们从中国西南的阳宗湖的一个具有良好年代记录的沉积物核心中建立了 PAHs 和痕量金属的历史污染数据，该湖于 2007 年经历了一场由锌精矿冶炼厂引发的严重尾矿泄漏事故，旨在评估其时间轨迹的异质性及其在区域沉积模式下的污染来源。沉积记录显示，在 1950 年代之前，PAHs 和痕量金属的浓度和通量一直保持在较低水平。1950 年代至 2002 年期间，PAHs 和痕量金属的浓度呈上升趋势且呈同步变化，与中国西部社会经济发展的时间模式非常一致，煤炭燃烧和冶炼工业是该地区的主要污染源。然而，砷（As）和 PAHs 在 2007-2013 年期间同时出现峰值，与这些污染物的区域模式形成鲜明对比。现代的 As 浓度比 1950 年前的水平高出 5-14 倍，而当代的 PAHs 浓度则上升了约 10-14 倍。沉积记录显示，阳宗湖集水区的冶炼活动的本地特征在过去十年中已经超过了大气输送的 As 和 PAHs 的临时模式。这突出了局部污染源在高度受影响的系统中调节甚至覆盖人为污染的区域性模式的重要作用。
