Trace metals in Northern New England streams: Evaluating the role of road salt across broad spatial scales with synoptic snapshots

PLoS One. 2019 Feb 13;14(2):e0212011. doi: 10.1371/journal.pone.0212011. eCollection 2019.

Abstract

Mobilization of trace metals from soils to surface waters can impact both human and ecosystem health. This study resamples a water sample archive to explore the spatial pattern of streamwater total concentrations of arsenic, cadmium, copper, lead, and zinc and their associations with biogeochemical controls in northern New England. Road deicing appears to result in elevated trace metal concentrations, as trace metal concentrations are strongly related to sodium concentrations and are most elevated when the sodium: chloride ratio is near 1.0 (~halite). Our results are consistent with previous laboratory and field studies that indicate cation exchange as a metal mobilization mechanism when road salt is applied to soils containing metals. This study also documents associations among sodium, chloride, dissolved organic carbon, iron, and metal concentrations, suggesting cation exchange mechanisms related to road deicing are not the only mechanisms that increase trace metal concentrations in surface waters. In addition to cation exchange, this study considers dissolved organic carbon complexation and oxidation-reduction conditions affecting metal mobility from soils in a salt-rich environment. These observations demonstrate that road deicing has the potential to increase streamwater trace metal concentrations across broad spatial scales and increase risks to human and ecosystem health.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Ecosystem
  • Environmental Monitoring*
  • Humans
  • Ice
  • Metals / analysis*
  • Motor Vehicles
  • New England
  • Rivers / chemistry*
  • Salinity
  • Sodium Chloride / analysis
  • Sodium Chloride / pharmacology*
  • Spatial Analysis
  • Trace Elements / analysis*
  • Transportation*

Substances

  • Ice
  • Metals
  • Trace Elements
  • Sodium Chloride

Grants and funding

Support for this study was provided by the National Science Foundation, Plymouth State University Center for the Environment, University of Pittsburgh Department of Geology and Environmental Science, New Hampshire Established Program to Stimulate Competitive Research (NSF EPS-1101245), and the U.S. Forest Service. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.