Ever since Levi Strauss made the first pair of denim pants with rivets on the stress points in 1873, blue jeans have steadily made their way around the world as a fashion staple for millions. Now though, research is showing that fibers from our jeans might be becoming a little too widespread.
Reporting in the journal, Environmental Science & Technology Letters, researchers say they have found denim microfibers in wastewater—which you might expect considering that part of it is composed of laundry water—but also in lakes and marine sediment in the remote Arctic.
In compiling their data, Miriam Diamond, Samantha Athey, and other colleagues from the Rochman Lab at the University of Toronto looked at water samples collected in Canadian lakes. They found that indigo denim made up 23% of all microfiber sediment in the Great Lakes; 12% of all microfiber sediment in suburban lakes near Toronto; and 20% in the Canadian Arctic Archipelago. To find the fibers, the team used microscopy and Raman spectroscopy—which analyzes light scattered by molecules to determine the specific makeup of a substance.
From 50,000 to One Billion
In addition to analyzing bodies of water, the researchers also conducted washing experiments and found that just one pair of jeans can shed more than 50,000 microfibers in the laundry. What’s more, in the analysis of the effluent from wastewater treatment plans, the researchers calculated that approximately one billion indigo denim microfibers are discharged every single day.
While denim is made of natural cotton cellulose fibers, the fact that it can stick around as small particles and travel as far as the Arctic is concerning.
“What’s really revealing here, and others have hinted at this in the literature, is that the Arctic is an ‘end node’ for subsurface currents,” Marcus Eriksen, who studies ocean plastic and directs the 5 Gyres Institute, told Wired. “What you have is the deep-water conveyor belt, which takes neutrally buoyant debris around the world, ending in the Arctic. Now we’re finding really high sediment loads of microplastics in Arctic sediments.” Eriksen wasn’t involved in the research.
Nicholas Mallos, senior director of the Ocean Conservancy’s Trash Free Seas Program, who also wasn’t involved in the research, told Wired that there are techniques such as special laundry filters that could be put in place now to catch some of the microfibers that are winding up in the environment.
“Regardless of whether something is synthetic or fibrous,” he said, “we know there are effective mitigation techniques out there available now that can help stem this pollution pathway into wastewater and ultimately into the marine environment.”