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Title: Identification of multiple mercury sources to stream sediments near Oak Ridge, TN, USA

In this paper, sediments were analyzed for total Hg concentration (THg) and isotopic composition from streams and rivers in the vicinity of the Y-12 National Security Complex (Y12) in Oak Ridge, TN (USA). In the stream directly draining Y12, where industrial releases of mercury (Hg) have been documented, high THg (3.26 to 60.1 μg/g) sediments had a distinct Hg isotopic composition (δ202Hg of 0.02 ± 0.15‰ and Δ199Hg of -0.07 ± 0.03‰; mean ± 1SD, n=12) compared to sediments from relatively uncontaminated streams in the region (δ202Hg = -1.40 ± 0.06‰ and Δ199Hg of –0.26 ± 0.03‰; mean ± 1SD, n=6). Additionally, several streams that are nearby but do not drain Y12 had sediments with intermediate THg (0.06 to 0.21 μg/g) and anomalous δ202Hg (as low as -5.07‰). We suggest that the low δ202Hg values in these sediments provide evidence for the contribution of an additional Hg source to sediments, possibly derived from atmospheric deposition. In sediments directly downstream of Y12 this third Hg source is not discernible and the Hg isotopic composition can be largely explained by the mixing of low THg sediments with high THg sediments contaminated by Y12 discharges.
 [1] ;  [1] ;  [1] ;  [2] ;  [2] ;  [3]
  1. Univ. of Michigan, Ann Arbor, MI (United States)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  3. Tennessee Department of Environment and Conservation, Oak Ridge, TN (United States)
Publication Date:
OSTI Identifier:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Environmental Science and Technology
Additional Journal Information:
Journal Volume: 48; Journal Issue: 7; Journal ID: ISSN 0013-936X
American Chemical Society (ACS)
Research Org:
Univ. of Michigan, Ann Arbor, MI (United States)
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
Country of Publication:
United States
54 ENVIRONMENTAL SCIENCES mercury isotopes; river sediments; East Fork Poplar Creek; Clinch River