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Mercury speciation and microbial transformations in mine wastes, stream sediments, and surface waters at the Almade??n Mining District, Spain

Environmental Science and Technology

By:
, , , , and
DOI: 10.1021/es040359d

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Abstract

Speciation of Hg and conversion to methyl-Hg were evaluated in mine wastes, sediments, and water collected from the Almade??n District, Spain, the world's largest Hg producing region. Our data for methyl-Hg, a neurotoxin hazardous to humans, are the first reported for sediment and water from the Almade??n area. Concentrations of Hg and methyl-Hg in mine waste, sediment, and water from Almade??n are among the highest found at Hg mines worldwide. Mine wastes from Almade??n contain highly elevated Hg concentrations, ranging from 160 to 34 000 ??g/g, and methyl-Hg varies from <0.20 to 3100 ng/g. Isotopic tracer methods indicate that mine wastes at one site (Almadenejos) exhibit unusually high rates of Hg-methylation, which correspond with mine wastes containing the highest methyl-Hg concentrations. Streamwater collected near the Almade??n mine is also contaminated, containing Hg as high as 13 000 ng/L and methyl-Hg as high as 30 ng/L; corresponding stream sediments contain Hg concentrations as high as 2300 ??g/g and methyl-Hg concentrations as high as 82 ng/g. Several streamwaters contain Hg concentrations in excess of the 1000 ng/L World Health Organization (WHO) drinking water standard. Methyl-Hg formation and degradation was rapid in mines wastes and stream sediments demonstrating the dynamic nature of Hg cycling. These data indicate substantial downstream transport of Hg from the Almade??n mine and significant conversion to methyl-Hg in the surface environment.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Mercury speciation and microbial transformations in mine wastes, stream sediments, and surface waters at the Almade??n Mining District, Spain
Series title:
Environmental Science and Technology
DOI:
10.1021/es040359d
Volume
38
Issue:
16
Year Published:
2004
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Environmental Science and Technology
First page:
4285
Last page:
4292
Number of Pages:
8