Toxicological impacts of roadway deicers on aquatic resources and human health: A review

Abstract

During winter, snow and ice on roads in regions with cold weather can increase traffic crashes and casualties, resulting in travel delays and financial burdens to society. Anti‐icing or deicing the roads can serve a cost‐effective method to significantly reduce such risks. Although traditionally the main priorities of winter road maintenance (WRM) have been level of service, cost‐effectiveness, and corrosion reduction, it is increasingly clear that understanding the environmental impacts of deicers is vital. One of the most important problems in this regard is environmental contamination caused by cumulative use of deicers, which has many detrimental effects on the aquatic systems. Among the deicers, the chloride‐based ones raise the most toxicological concerns because they are highly soluble, can migrate quickly in the environment and have cumulative effects over time. In this review, we summarize and organize existing data, including the latest findings about the adverse effects of deicers on surface water and groundwater, aquatic species, and human health, and identify future research priorities. In addition, the data provided can be used to develop a framework for quantifying some of the variables that stakeholders and agencies use when preparing guidelines and standards for WRM programs. Practitioner points Pollution from the increasing use of roadway deicers may have detrimental effects on the environment. Of particular concern are the acute and cumulative risks that chloride salts pose to aquatic species. Chloride salts are water‐soluble, very difficult to remove, highly mobile, and non‐degradable. Deicers cause water stratification, change the chemicophysical properties of water, and affect aquatic species and human health. Current guidelines may not be appropriate for environmental protection and need to be revised.

Femtosecond laser composite manufactured double-bionic micro–nano structure for efficient photothermal anti-icing/deicing

“…Currently, common active deicing tactics include electro-thermal methods, 4 photothermal methods, 5–7 mechanical removal, 8 and chemical methods. 9 Among these techniques, photothermal deicing shows great prospects due to the inexhaustible supply of solar energy, and it is highly consistent with the sustainable development concept. 10,11 It converts the absorbed solar energy into heat using photothermal conversion materials, thus keeping the temperature above freezing point to activate anti-icing/deicing.…”

Toxicity and chemical composition of commercial road palliatives versus oil and gas produced waters

“…Road maintenance workers are potentially exposed to organic compounds present in road palliatives during material handling and application to road surfaces. Additional exposure could occur from the inhalation of contaminated particulate matter released from roads (Honarvar Nazari et al, 2021).…”

“…Most research has focused on salt used for WRM (Fay and Shi, 2012;Hintz and Relyea, 2019;Asensio et al, 2017;Nazari et al, 2015;Arnott et al, 2020), but rising salinity in streams and groundwater near roads treated with chloride-based dust suppressants has also been reported (Goodrich et al, 2009a;Eckstein, 2011;Bair and Digel, 1990). Freshwater salinization impacts drinking water resources (Eckstein, 2011;Pieper et al, 2018) and poses risks to roadside vegetation (Goodrich and Jacobi, 2012;Goodrich et al, 2009b) and aquatic organisms at all trophic levels (Hintz and Relyea, 2019;Arnott et al, 2020;Honarvar Nazari et al, 2021).…”

Differential Impacts of Road De-icers on Freshwater Bacterial Communities

“…In contrast, today's cheap and abundant salt supplies mean that only considering Canada and the USA, ~25 million tonnes are cast yearly on roads and similar infrastructure to serve as temporary de-icers [1,2]. Salt (NaCl) applications to improve winter transportation safety started in the 1940s, but in the last three decades concerns about the environmental costs have mounted since chloride brine disrupts roadside vegetation, pollutes ground water and aquatic ecosystems, as well as impacts biodiversity, food webs, and trophic interactions [3][4][5][6][7]. In turn, governments have issued freshwater guidelines for chloride pollution with limits set at 120 and 230 mg/L for chronic toxicity levels in Canada and the USA, respectively, with the corresponding levels for acute toxicity at 640 and 860 mg/L [8,9].…”