Read the full story in the Washington Post.
In the 1940s, Americans found a new way to love salt. Not simply for sprinkling on food — we’d acquired a taste for the mineral long before that — but for spreading on roads and sidewalks. Salt became a go-to method to de-ice frozen pavement.
During the past half-century, annual U.S. sales of road salt grew from 160,000 tons to about 20 million tons, as a group of environmental scientists pointed out in a study published Monday in the Proceedings of the Natural Academy of the Sciences. NaCl kept roads free from slippery ice, but it also changed the nature of North America’s freshwater lakes. Of 371 lakes reviewed in the new study, 44 percent showed signs of long-term salinization.