In the washer, millions of plastic microfibers are shed from clothing that contain materials such as nylon, polyester, and acrylic. These fibers are so small that they drain out of the washing machine and often make their way into the marine environment, where they are ingested by animals.
Two years ago, Newcastle University scientists demonstrated for the first time that microfibers are now present in the deepest parts of the ocean. In a new study, the team discovered that the amount of water used during the wash cycle is the main factor that influences the release of microfibers from clothing.
The scientists found that more fibers were released in higher volumes of water, regardless of the speed or spinning force of the washing machine. In addition, the experts determined that 800,000 more fibers were released during a delicate wash compared to a standard cycle.
“Counterintuitively, we discovered that ‘delicate’ cycles release more plastic microfibers into the water, and then the environment, than standard cycles,” explained study lead author and PhD student Max Kelly.
“Previous research has suggested the speed the drum spins at, the number of times it changes spinning direction during a cycle and the length of pauses in the cycle – all known as the machine agitation – is the most important factor in the amount of microfiber released.”
“But we have shown here that even at reduced levels of agitation, microfiber release is still greatest with higher water-volume-to-fabric ratios. This is because the high volume of water used in a delicate cycle which is supposed to protect sensitive clothing from damage actually ‘plucks’ away more fibers from the material.”
Laundry has been previously acknowledged as being a major contributor of plastic particles, but obtaining a precise measurement has been challenging.
The Newcastle team used a tergotometer, a benchtop device made up of eight washing vessels that simulate full-scale domestic washing, which allowed the experts to test under different conditions. A digital color imaging system was then used to calculate the amount of microfibers released.
The results of the study show that previous recommendations to move toward high water volumes and low levels of agitation were only making the microfiber issue worse.
“The appliance industry has started to introduce microfiber filters in some new washing machines and the textile industry is looking to reduce the fiber shedding levels of new clothing,” said study co-author Neil Lant, who is a research fellow at Procter & Gamble in Newcastle. “We hope that the issue will ultimately be solved by such actions, and our work on the mechanistic causes will help in the development of these solutions.”
Kelly emphasized that reducing the amount of plastic pollution is everyone’s responsibility and that it is often the small changes that make a huge difference.
“By avoiding high water-volume-to-fabric washes such as the delicate cycles and ensuring full wash loads then we can all do our bit to help reduce the amount of these synthetic fibers being released into the environment,” said Kelly.
“Hopefully, these findings may also be used by manufacturers to influence the design of future washing machines and reduce our plastic footprint. Over time these changes could also see a global reduction in the amount of energy and water required to wash our clothes.”
The study is published in the journal Environmental Science and Technology.
Image Credit: Shutterstock/Werayuth Tes