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Historical Records of Mercury Stable Isotopes in Sediments of Tibetan Lakes

The Tibetan Plateau (TP), known as the “Third Pole”, is a critical zone for atmospheric mercury (Hg) deposition. Increasing anthropogenic activities in the globe leads to environmental changes, which may affect the loading, transport and deposition of Hg in the environment. However, the deposition h...

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Autores principales: Yin, Runsheng, Feng, Xinbin, Hurley, James P., Krabbenhoft, David P., Lepak, Ryan F., Kang, Shichang, Yang, Handong, Li, Xiangdong
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4800404/
https://www.ncbi.nlm.nih.gov/pubmed/26996936
http://dx.doi.org/10.1038/srep23332
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author Yin, Runsheng
Feng, Xinbin
Hurley, James P.
Krabbenhoft, David P.
Lepak, Ryan F.
Kang, Shichang
Yang, Handong
Li, Xiangdong
author_facet Yin, Runsheng
Feng, Xinbin
Hurley, James P.
Krabbenhoft, David P.
Lepak, Ryan F.
Kang, Shichang
Yang, Handong
Li, Xiangdong
author_sort Yin, Runsheng
collection PubMed
description The Tibetan Plateau (TP), known as the “Third Pole”, is a critical zone for atmospheric mercury (Hg) deposition. Increasing anthropogenic activities in the globe leads to environmental changes, which may affect the loading, transport and deposition of Hg in the environment. However, the deposition history and geochemical cycling of Hg in the TP is still uncertain. Our records of Hg and Hg isotopes in sediment profiles of the two largest lakes in the TP, Lake Qinghai and Nam Co, show increased Hg influx since last century, with the maximum Hg influx enrichment ratios of 5.4 and 3.5 in Lake Qinghai and Nam Co, respectively. Shifts in negative δ (202)Hg in Lake Qinghai (−4.55 to −3.15‰) and Nam Co (−5.04 to −2.16‰) indicate increased atmospheric Hg deposition through rainfall, vegetation and runoff of soils. Mass independent fractionation of both even-Hg (∆ (200)Hg: +0.05 to +0.10‰) and odd-Hg (∆ (199)Hg: +0.12 to +0.31‰) isotopes were observed. Positive Δ (200)Hg suggest high proportion of precipitation-derived Hg in the TP, whereas the positive Δ (199)Hg results from Hg(II) photo-reduction. Both lakes show increasing Δ (199)Hg since the 1900 s, and we conclude that with the decrease of ice duration, Hg(II) photo-reduction may have been accelerated in these TP lakes.
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spelling pubmed-48004042016-03-22 Historical Records of Mercury Stable Isotopes in Sediments of Tibetan Lakes Yin, Runsheng Feng, Xinbin Hurley, James P. Krabbenhoft, David P. Lepak, Ryan F. Kang, Shichang Yang, Handong Li, Xiangdong Sci Rep Article The Tibetan Plateau (TP), known as the “Third Pole”, is a critical zone for atmospheric mercury (Hg) deposition. Increasing anthropogenic activities in the globe leads to environmental changes, which may affect the loading, transport and deposition of Hg in the environment. However, the deposition history and geochemical cycling of Hg in the TP is still uncertain. Our records of Hg and Hg isotopes in sediment profiles of the two largest lakes in the TP, Lake Qinghai and Nam Co, show increased Hg influx since last century, with the maximum Hg influx enrichment ratios of 5.4 and 3.5 in Lake Qinghai and Nam Co, respectively. Shifts in negative δ (202)Hg in Lake Qinghai (−4.55 to −3.15‰) and Nam Co (−5.04 to −2.16‰) indicate increased atmospheric Hg deposition through rainfall, vegetation and runoff of soils. Mass independent fractionation of both even-Hg (∆ (200)Hg: +0.05 to +0.10‰) and odd-Hg (∆ (199)Hg: +0.12 to +0.31‰) isotopes were observed. Positive Δ (200)Hg suggest high proportion of precipitation-derived Hg in the TP, whereas the positive Δ (199)Hg results from Hg(II) photo-reduction. Both lakes show increasing Δ (199)Hg since the 1900 s, and we conclude that with the decrease of ice duration, Hg(II) photo-reduction may have been accelerated in these TP lakes. Nature Publishing Group 2016-03-21 /pmc/articles/PMC4800404/ /pubmed/26996936 http://dx.doi.org/10.1038/srep23332 Text en Copyright © 2016, Macmillan Publishers Limited http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/
spellingShingle Article
Yin, Runsheng
Feng, Xinbin
Hurley, James P.
Krabbenhoft, David P.
Lepak, Ryan F.
Kang, Shichang
Yang, Handong
Li, Xiangdong
Historical Records of Mercury Stable Isotopes in Sediments of Tibetan Lakes
title Historical Records of Mercury Stable Isotopes in Sediments of Tibetan Lakes
title_full Historical Records of Mercury Stable Isotopes in Sediments of Tibetan Lakes
title_fullStr Historical Records of Mercury Stable Isotopes in Sediments of Tibetan Lakes
title_full_unstemmed Historical Records of Mercury Stable Isotopes in Sediments of Tibetan Lakes
title_short Historical Records of Mercury Stable Isotopes in Sediments of Tibetan Lakes
title_sort historical records of mercury stable isotopes in sediments of tibetan lakes
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4800404/
https://www.ncbi.nlm.nih.gov/pubmed/26996936
http://dx.doi.org/10.1038/srep23332
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