Toxicological Impacts of Roadway Deicers on Aquatic Resources and Human Health: A Review.

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 be 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, 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 mobile, 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 provide a framework for quantifying some of the variables that stakeholders and agencies use when preparing guidelines and standards for WRM systems.