Legacy Lead Stored in Catchments Is the Dominant Source for Lakes in the U.K.: Evidence from Atmospherically Derived 210Pb.
Legacy Lead Stored in Catchments Is the Dominant Source for Lakes in the U.K.: Evidence from Atmospherically Derived 210Pb.
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DOI：
10.1021/acs.est.8b04099
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发表时间：
2018-11
影响因子：
11.4
通讯作者：
Handong Yang;E. Shilland;P. Appleby;N. Rose;R. Battarbee
中科院分区：
文献类型：
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作者：
Handong Yang;E. Shilland;P. Appleby;N. Rose;R. Battarbee
近几十年来，大气中的铅（Pb）人为排放量已大大减少。然而，在许多湖泊中的铅输入量的减少并不匹配，这是因为铅存储在集水区上层土壤层，来自以前的沉积，已成为一个重要的来源，虽然它是难以定量评估。这项工作使用大气沉积的210 Pb作为示踪剂来跟踪Pb的运动，因此，我们第一次能够计算出英国湖泊中直接大气沉积和集水来源的相对Pb输入。直接.在个别湖泊网站，210铅/铅的比值在集水陆生苔藓通常是一个数量级高于集水表层土壤，湖泊沉积物，并在湖底的表层沉积物。结果表明，苔藓植物中Pb同位素特征与大气沉积特征接近或主要受大气沉积特征的影响，用年降水量大于2000 mm的湖泊站点的陆生苔藓中210 Pb/Pb比值来代表大气沉积特征是合理的。结果表明，在铅排放量减少后，流域铅输入现在通常占进入湖泊的总铅的95%以上。
There has been a considerable reduction in anthropogenic lead (Pb) emission in the atmosphere in recent decades. However, the reduction in Pb inputs in many lakes does not match this as the Pb stored in catchment upper soil layers, derived from previous deposition, has become an important source although it is difficult to assess quantitatively. This work uses atmospherically deposited 210Pb as a tracer to track Pb movement, and so for the first time, we were able to calculate the relative Pb inputs from direct atmospheric deposition and catchment sources to lakes in the U.K. directly. Within individual lake sites, ratios of 210Pb/Pb in the catchment terrestrial mosses were normally an order of magnitude higher than those in the catchment surface soils, trapped lake sediments, and the surface sediments in the lake bottom. Results suggest that the Pb isotope signatures in the mosses are close to or dominated by atmospheric depositions, and it is reasonable to use the ratios of 210Pb/Pb in terrestrial mosses collected from the lake sites with a high annual rainfall over 2000 mm to represent those in atmospheric depositions. It reveals that after the reduction in Pb emissions, catchment Pb inputs now typically account for more than 95% of the total Pb entering the lakes.