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

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.

Evaluation of the Clinton River Watershed Water Quality as an Indication of Salinization due to Road Deicing Methods

“…The study tracked Aluminum, Copper, Lead, Zinc, Sodium, and Chloride. Through an analysis of 70 sites, researchers found Na+ to spread at a rate of 13.1(μg/L) and Cl-at 23.7(μg/L) 21 . Although this may seem insignificant, results from non-winter months were 3.2(μg/L) and 5.4(μg/L), respectively 21 .…”

“…Through an analysis of 70 sites, researchers found Na+ to spread at a rate of 13.1(μg/L) and Cl-at 23.7(μg/L) 21 . Although this may seem insignificant, results from non-winter months were 3.2(μg/L) and 5.4(μg/L), respectively 21 . This finding insinuates that during the winter, there is not only a substantial increase in ion content but also at the rate they spread.…”

Metal accumulation patterns in Pittsburgh, PA (United States) green infrastructure soils: road connections and legacy soil inputs

“…When contaminated sediments are introduced to novel geochemical environments, contaminant cycling can evolve in unexpected ways (Danfoura and Gurdak, 2016). Further, metals can be mobilized by road deicer salts (Bäckström, et al, 2004;Wilhelm, et al, 2019) to complex soil water flow paths that create salt plumes that persist following the cold season (Rossi, et al, 2017). Further, even if GI are constructed with imported, relatively clean soil materials, these engineered soils interact with environments rich with legacy contamination.…”

Comparing Trace Elements (As, Cu, Ni, Pb, and Zn) in Soils and Surface Waters among Montane, Upland Watersheds and Lowland, Urban Watersheds in New England, USA

“…Natural weathering of their metamorphosed bedrock can release trace elements from accessory minerals, particularly sulfides and iron oxides [21]. Upland sites are very acidic pH (3.6 to 5.2) and can mobilize trace elements complexed to DOC [22] and lowland sites have historical pollution of As, Cu, Pb, Ni, and Zn from tanneries, mills, industrial manufacturing, smelting, and agricultural pesticides and fertilizers [1][2][3][4]23]. Furthermore, lowland areas have modern sources of domestic pollution from vehicles and vehicle exhaust.…”