It’s that time of year when roads are treated and salted in preparation for ice and snow. While road salt can help prevent collisions and allow safer travel in the winter, there is a great cost to us and our environment when using it. Road salts are most commonly made from sodium chloride, and chloride notoriously breaks down steel and concrete. Road salts are estimated to cause $5 billion in damage to infrastructure and cars each year (EPA, 2020). Salt water corrodes pipes, further increasing pollution and infrastructure damage (Maryland DNR, 2021). Water desalination is costly and difficult, so essentially, when salt gets into our waterways, it stays there. Beyond economic impacts, road salts harm soil, freshwater, and wildlife.
Road salts harm amphibians and freshwater fish’s ability to osmoregulate (Maryland DNR, 2021). Salt also damages fish eggs and young fish. For amphibians like frogs, salts are especially harmful because of their porous skin. Salt can also impact their morphology, as seen in wood frogs. Wood frogs are a species of frog found in Maryland, and have been proven to have a less likely chance to be female as they develop when exposed to salts (Lambert et. al, 2017). Salt also attracts certain mammals like deer to the roads, and increases their risk of being struck by a car (Maryland DNR, 2021). Salination of waters and soils cause terrestrial and aquatic plant growth alike to be slowed when exposed to salts. Salt even harms the microbes that perform denitrification, which both increases nitrogen runoff and impacts plant growth (Stranko, et al., 2013).
Luckily, there are programs and training initiatives in Maryland to help minimize salt use, but there is no legal limitation on the amount of salt that can be used. Be mindful of the use of road salt; even the amount used personally can help make a difference for our environment.
References:
Lambert, M. R., Stoler, A. B., Smylie, M. S., Relyea, R. A., & Skelly, D. K. (2016, November 22). Interactive effects of road salt and leaf litter on wood frog sex ratios and sexual size dimorphism. Canadian Journal of Fisheries and Aquatic Sciences, 74(2), 141-146. https://doi.org/10.1139/cjfas-2016-0324
Stranko, S., Zimmerman, J., & Maryland Department of Natural Resources. (2013, April). Do Road Salts Cause Environmental Impacts? Maryland Department of Natural Resources. https://dnr.maryland.gov/streams/Publications/RoadSalt2013.pdf
Maryland Department of the Environment. (2021). Statewide Winter Salts Efforts. mde.maryland.gov. https://mde.maryland.gov/programs/water/319NonPointSource/Pages/Statewide-Efforts.aspx
United States Environmental Protection Agency. (2020, November). Winter is Coming! And with it, tons of salt on our roads. US Environmental Protection Agency. https://www.epa.gov/snep/winter-coming-and-it-tons-salt-our-roads