The Washington Post –
Nearly everywhere you turn during this frigid stretch of winter, much of the world seems covered in a layer of salt aimed at keeping our roads drivable and sidewalks free of ice. All that salt is one reason — although not the only one — that many of the nation’s rivers and streams are becoming saltier, according to new research published Monday in the Proceedings of the National Academy of Sciences.
Increased salt poses risks to drinking-water supplies for millions of Americans, threatens urban infrastructure, and has the potential to upend ecosystems.
“The fact it is occurring so widely surprised us,” said Gene Likens, an author of the new study who is a University of Connecticut professor and president emeritus of the Cary Institute of Ecosystem Studies. “The impacts we humans are having on natural systems are really widespread.”
Researchers used five decades’ worth of data from 232 U.S. Geological Survey monitoring sites to document long-term changes in the salinity of rivers and streams throughout the country, as well as changes in their acidity. They documented stark chemical changes in major waterways, such as the Hudson, Potomac and Mississippi rivers, which supply drinking water to major population centers.