Earlier in January, a polar vortex brought frigid temperatures and record amounts of snow to much of the United States. Many states carpeted roads with crunchy salt to battle icy conditions.
While this strategy may help keep drivers safe, it causes widespread damage to the environment, research shows. The U.S. uses about 25 million tons of salt on roads each year, according to one estimate. Much of this runs off into freshwater ecosystems, increasing salinity to levels that can be toxic to humans and wildlife alike.
That’s one of the ways that humans are increasingly disrupting Earth’s natural “salt cycle,” which describes how the mineral moves through the environment. Experts are urging governments and individuals to decrease their road salt usage—a movement that is picking up steam but still faces barriers as regions adapt to unpredictable weather.
Salty Species: First off, happy Winter Salt Awareness Week! If you are anything like me, you may also be learning about this multi-state initiative for the first time—and wondering why it even exists. I mean, how bad can the road salt issue really be?
Turns out, it’s pretty bad. Between 2013 and 2017, around 44 percent of the salt used in the U.S. was for de-icing the roads. Massachusetts alone uses nearly half a million tons of salt each year for winter road maintenance, according to the U.S. Environmental Protection Agency.
“We’re a salty species,” Sujay Kaushal, a geologist at the University of Maryland, told me. “We have all this salt that we’re using for different things, [like] de-icing roads, we use it in household products where we have detergents and things like that that have salt, and we have wastewater that’s enriched in salts that we release back into streams and rivers and lakes.”
Kaushal has been studying for years how humans are ramping up the amount of salt in the natural environment—what he referred to as an “anthropogenic salt cycle.” In fact, he spoke with me while he was on his way to sample the saltiness of a nearby stream in Maryland after a recent snow event.
In 2021, Kaushal and a team of researchers published a study that found introducing salt into the environment, whether from de-icing roads or fertilizing farmland, releases toxic chemical cocktails and decreases our availability of freshwater resources, which is already dwindling due to climate change. If salinity levels are too high, drinking salty water can cause dehydration, or exacerbate certain medical conditions like high blood pressure and chronic kidney disease, studies show.
But it’s not just humans at risk. A growing body of research shows that saltwater contamination from road maintenance is drying out some plant species and harming animals such as frogs, insects and fish. Veterinarians say that road salt can even hurt your pet dog’s paws, causing dryness, burning and irritation.
Kaushal adds that salt can also encourage the growth of certain invasive plants such as Phragmites grasses, which are more salt tolerant and can outcompete native plants for resources. In some cases, salty roads may even add some risk to driving. Road salt can cause corrosive damage to vehicles in the long term or increase the risk of wildlife-vehicle collisions by attracting deer and moose (which like to lick the brine), according to the EPA.
Balancing Act: These salty consequences are playing out worldwide. Since 2019, the nonprofit Ottawa Riverkeeper in Canada has been working with citizen scientists to collect about 500 water samples from 45 locations at streams in populated areas. Only about 10 percent of the samples collected over the five-year study period had safe levels of chloride, one of the main molecules in salt, according to a new report released by the organization on Monday. Many of the freshwater sites they sampled had a chloride concentration over 120 milligrams per liter for an extended period of time, indicating “chronic toxicity,” said Larissa Holman, Ottawa Riverkeeper’s director of science and policy.
“The biggest surprise to us was just how awful it was. Like, the levels are just consistently terrible and the reason why this is so bad is because it’s something that we are doing to our environment,” Holman told me. She added that they also identified high levels of salinity in certain areas during the summer months, likely due to the road salt being trapped in sediment.
Experts agree that de-icing salt is necessary to help people stay safe on the roads. But they also agree that we are using entirely too much of it.
Officials say that just a coffee mug’s worth of salt—around 12 ounces—is enough to treat a 20-foot driveway. Many people and communities use far more than this.
In recent years, there have been state- and community-led pushes in some areas to minimize road salt use. For example, a coalition of nonprofits and government groups in Wisconsin—dubbed Wisconsin Salt Wise—has been training people on the appropriate use of road salt during winter. There are similar initiatives in other states across the Northeast and Midwest, and in Canada. In some cases, states are offering training to applicators to ensure they are calibrating their salt use accurately based on the weather and proximity to ecologically sensitive areas or drinking water, Grist reports.
“We need to balance safety with our use,” Kaushal said. “The real way to treat the problem is to figure out ways to reduce the amount of salt that we use.”
More Top Climate News
On Monday evening, the White House announced a freeze on already approved federal grants and loans, sparking nationwide confusion and concern about everything from clean water access to disaster recovery, which my colleague Nicholas Kusnetz reported on. A judge then temporarily blocked the memo, and by Wednesday, the Trump administration rescinded it.
However, farmers, activists, organizations and businesses are worried their funding and the programs they rely on may still be in limbo, Melina Walling reports for The Associated Press. Among the programs at risk include federal grant funding to help fix crumbling water infrastructure, support renewable energy projects and increase availability for electric school buses, a Biden-era initiative I wrote about in April. The White House says Trump’s executive orders remain in force for now, and some place a freeze on funding, including for environmental programs in the Inflation Reduction Act and the bipartisan infrastructure law.
Meanwhile, the U.S. Senate has confirmed a range of top-ranking cabinet members and White House officials this week that could impact climate policy, including EPA Administrator Lee Zeldin, Interior Secretary Doug Burgum and Transportation Secretary Sean Duffy. Duffy has targeted federal climate initiatives in some of his first acts as DOT head, signing an order to roll back former President Joe Biden’s fuel economy standards aimed at reducing pollution and issuing a memorandum to “identify and eliminate” Biden policies that “reference or relate in any way” to climate change, “‘greenhouse gas’ emissions” or environmental justice, Jessica Hullinger reports for Heatmap News.
President Donald Trump announced on Thursday that he plans to impose 25 percent tariffs on goods from Mexico and Canada by Saturday, Brett Samuels reports for The Hill. “We will really have to do that because we have very big deficits with those countries,” Trump told reporters in the Oval Office. “Those tariffs may or may not rise with time.” This could affect the prices consumers pay on a range of products—from avocados to cars. However, Trump says he may not include oil in the list of products being taxed from Canada. The White House Press Secretary Karoline Leavitt confirmed today that the tariffs will be in place starting tomorrow.
The fires that have torn through greater Los Angeles are largely contained, but their impacts are expected to linger for years to come. Many people are still displaced from their homes, which has inhibited Los Angeles County’s ability to accurately count the number of unhoused people in the region—a survey that is crucial for deciding where and how to allocate certain services and funding, Erin Rode reports for High Country News. This situation represents a broader issue as climate-fueled disasters push an increasing number of people from their homes, temporarily or in the long term.
About This Story
Perhaps you noticed: This story, like all the news we publish, is free to read. That’s because Inside Climate News is a 501c3 nonprofit organization. We do not charge a subscription fee, lock our news behind a paywall, or clutter our website with ads. We make our news on climate and the environment freely available to you and anyone who wants it.
That’s not all. We also share our news for free with scores of other media organizations around the country. Many of them can’t afford to do environmental journalism of their own. We’ve built bureaus from coast to coast to report local stories, collaborate with local newsrooms and co-publish articles so that this vital work is shared as widely as possible.
Two of us launched ICN in 2007. Six years later we earned a Pulitzer Prize for National Reporting, and now we run the oldest and largest dedicated climate newsroom in the nation. We tell the story in all its complexity. We hold polluters accountable. We expose environmental injustice. We debunk misinformation. We scrutinize solutions and inspire action.
Donations from readers like you fund every aspect of what we do. If you don’t already, will you support our ongoing work, our reporting on the biggest crisis facing our planet, and help us reach even more readers in more places?
Please take a moment to make a tax-deductible donation. Every one of them makes a difference.
Thank you,
Kiley Price
Reporter
Kiley Price is a reporter at Inside Climate News, with a particular interest in wildlife, ocean health, food systems and climate change. She writes ICN’s “Today’s Climate” newsletter, which covers the most pressing environmental news each week.
She earned her master’s degree in science journalism at New York University, and her bachelor’s degree in biology at Wake Forest University. Her work has appeared in National Geographic, Time, Scientific American and more. She is a former Pulitzer Reporting Fellow, during which she spent a month in Thailand covering the intersection between Buddhism and the country’s environmental movement.
