The mechanism governing how plastic fibres move through the environment has been uncovered for the first time. The new research implicating water filtration systems and sewage sludge could help reduce plastics pollution around the world.
Millions of tons of plastic waste from sources including synthetic clothing fibres, cosmetics and packaging are bobbing around the world’s oceans in microscopic pieces and are finding their way into soil, sediments and freshwater.
Now, new research has for the first time modeled how these microplastic fibers move through the environment. The work conducted at Washington State University could help communities better understand and reduce plastics pollution.
“I wanted to know whether they keep moving and spreading or if they just accumulate in one place,” explained researcher Nick Engdahl in a statement.
He used a novel physics-based approach to simulate the movement of microplastic fibers. These synthetic fibers in clothing are created during their manufacturing process and are shed every time you walk or rub your clothes against something.
The microfibers, which are mainly released when clothes are washed, end up in wastewater plants, where a significant proportion pass through water filtration systems. Even the ones that are filtered end up in sewage sludge that can be applied to farm soils as fertilizer or dumped in landfills, according to the statement.
Engdahl found that the length of the fibers and the speed of water that they’re floating in determined whether they settle in soil or continue moving in the environment. The movement of shorter microplastic fibers was complex, as well as faster than dissolved substances in the water.
Now working to verify and refine his model against direct observations of microplastic fiber movement in a lab, Engdahl also plans to measure the fibers in a wastewater treatment facility.
“The more data I can get from the real world, the more accurately I will be able to see if these things move around or stay put and pile up,” he said. “This will help us more accurately measure their environmental impact, which is largely unknown right now.”
Photo credit: Michael Coghlan/ CC BY-SA 2.0