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Atmospheric mercury deposition during the last 270 years--A glacial ice core record of natural and anthropogenic sources

Environmental Science & Technology

By:
ORCID iD , ORCID iD , ORCID iD , , , ORCID iD , , , and
https://doi.org/10.1021/es0157503

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Abstract

Mercury (Hg) contamination of aquatic ecosystems and subsequent methylmercury bioaccumulation are significant environmental problems of global extent. At regional to global scales, the primary mechanism of Hg contamination is atmospheric Hg transport. Thus, a better understanding of the long-term history of atmospheric Hg cycling and quantification of the sources is critical for assessing the regional and global impact of anthropogenic Hg emissions. Ice cores collected from the Upper Fremont Glacier (UFG), Wyoming, contain a high-resolution record of total atmospheric Hg deposition (ca. 1720−1993). Total Hg in 97 ice-core samples was determined with trace-metal clean handling methods and low-level analytical procedures to reconstruct the first and most comprehensive atmospheric Hg deposition record of its kind yet available from North America. The record indicates major atmospheric releases of both natural and anthropogenic Hg from regional and global sources. Integrated over the past 270-year ice-core history, anthropogenic inputs contributed 52%, volcanic events 6%, and background sources 42%. More significantly, during the last 100 years, anthropogenic sources contributed 70% of the total Hg input. Unlike the 2−7-fold increase observed from preindustrial times (before 1840) to the mid-1980s in sediment-core records, the UFG record indicates a 20-fold increase for the same period. The sediment-core records, however, are in agreement with the last 10 years of this ice-core record, indicating declines in atmospheric Hg deposition.

Additional publication details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Atmospheric mercury deposition during the last 270 years--A glacial ice core record of natural and anthropogenic sources
Series title:
Environmental Science & Technology
DOI:
10.1021/es0157503
Volume:
36
Issue:
11
Year Published:
2002
Language:
English
Publisher:
American Chemical Society
Contributing office(s):
Toxic Substances Hydrology Program
Description:
8 p.
First page:
2303
Last page:
2310