Road salts, human safety, and the rising salinity of our fresh waters

Abstract

In the US, 70% of the population lives in regions that experience snow and ice. Road deicing salts reduce vehicular accident rates in these regions by >78% but have led to dramatic increases in freshwater salinity. To seek environmental management and policy solutions, we ask: (1) how much salt is used and where is it applied, (2) do current agency thresholds protect freshwater biota, (3) are deicing salts affecting our water supplies, and (4) how can we curb salinization from deicing salts? Use of deicing salts has tripled over the past 45 years and blankets much of the US. There is an urgent need to reassess inadequate thresholds to protect freshwater biota and our drinking water supplies. Given the lack of ecologically friendly and cost‐effective alternatives, broad‐scale adoption of best management practices is necessary to curb the increasing salinization of freshwater ecosystems resulting from the use of deicing salts.

Snow particles physiochemistry: feedback on air quality, climate change, and human health

“…And when water with a high concentration of Cl À enters municipal water supplies, the water plumbing may undergo dezincication and galvanic corrosion, thinning pipe walls and releasing Pb into drinking water, which severely threatens human health of residents. 282 The atmosphere may also be affected from salt addition to snow in the cities. High concentrations of chloride found in urban cities in winter period, and the concentration of photoactive chlorine in the atmosphere showed a positive correlation with the concentration of chloride.…”

“…282 Thus, most efforts in snow management are focused on optimizing snow removal strategies to lower the cost of snowplows and reduce the usage of deicers. 282,287 However, it should be noted that, as discussed in Sections 2 and 4, snowpack on the roads can serve as a good reservoir for vehicular exhausts and emerging contaminants. Even aer snow removal by snowplows, it is necessary to treat those snow properly.…”

“…However, there are increasing concerns about using NaCl. [279][280][281][282][283] First, using NaCl will increase the salinity of fresh water when snow or ice melts, threatening the biota in fresh waters. Secondly, soil which absorbs snowmelt with high salinity cannot support vegetation growth.…”

“…At present, there is no cost-effective and environmental-friendly alternative for NaCl. 282 Thus, most efforts in snow management are focused on optimizing snow removal strategies to lower the cost of snowplows and reduce the usage of deicers. 282,287 However, it should be noted that, as discussed in Sections 2 and 4, snowpack on the roads can serve as a good reservoir for vehicular exhausts and emerging contaminants.…”

Zooplankton Dominance Shift in Response to Climate-Driven Salinity Change: A Mesocosm Study

“…The combined effects of climate change, habitat loss and degradation has put substantial strain on aquatic ecosystems (Travis, 2003). One specific pressure on both marine and freshwater environments globally includes changing salinity, as a result of direct human activity such as 'salting' roads (Schuler et al, 2017;Hintz et al, 2021) as well as climate change; predicted to affect precipitation and ice melt (Helm et al, 2010;Ross et al, 2021). Salinity change can have a profound impact on aquatic organisms, including altering the distribution, phenology, abundance, composition and trophic interactions of plankton (Intergovernmental Panel Climate Change, 2018).…”