The clothes you wear could be contributing to the sickening of the oceans
GEORGETOWN, South Carolina — The emergence of microplastics as a pollutant-harboring hazard in the oceans is a hot topic in scientific circles, but recent research by a Clemson University scientist and his collaborators suggests there is another potential danger lurking in marine habitats that has been previously ignored.
Natural fibers like cotton, linen, silk and wool also appear to be significant absorbers and transporters of organic chemicals in aquatic environments. Though these fibers degrade far faster than plastics and other synthetic materials, they remain intact long enough to have adverse effects on seaside areas.
“While taking sand samples from multiple sites throughout the southeastern coastal region of the United States to study the distribution of microplastics in our oceans, we also discovered the presence of sizable amounts of natural fibers,” said Alex Chow, an associate professor in the forestry and environmental conservation department of Clemson’s College of Agriculture, Forestry and Life Sciences. “These fibers have been neglected in marine pollution studies, probably because most believe they degrade before they can cause any appreciable harm. However, we are proposing that natural fibers are playing a different but still damaging role in chemical pollution dissemination.”
Microplastics, which are barely visible to the naked eye, arise through several processes, including the breakdown of larger plastic fragments and also the dispersal of household and personal care products that contain scrubs and abrasives. These particles enter the oceans via discharges from wastewater treatment plants, coastal tourism activities and shipping spillages. Either before discharge or after entering the ocean, microplastics absorb organic pollutants, such as medical and agricultural wastes, paint additives and wood preservatives. Because the plastic particles take decades to degrade, they can ride lengthy currents and transport these pollutants to places as distant as the relatively pristine regions of the Arctic.
Natural fibers, meanwhile, are believed to enter the marine environment mostly via the discharge of water from washing machines. A single cloth garment sheds hundreds of fibers per wash. These fibers, which are tiny enough to pass through wastewater treatment filters, degrade in a month or less. But this is still enough time for them to remain intact from their urban origin to their eventual resting places in coastal sediments.
“We propose that natural fibers can, in some ways, be even more harmful than synthetics,” said Chow, who is based at the Belle W. Baruch Institute of Coastal Ecology and Forest Science in Georgetown. “Both have been proven to absorb chemical pollutants, but synthetics help keep these pollutants unavailable to the environment for longer times in comparison to quickly degrading natural fibers, which release the pollutants much faster. Natural fibers also might be attracting a different set of chemicals that have the potential to lead to great physiological damage.”
The dispersal of organic pollutants causes ecological impairment in many ways. Small sea animals like oysters and shrimp consume both the microplastic and natural fibers. The small animals are then eaten by larger ones, which eventually affects the entire food chain. When humans eat the contaminated animals, the accumulated toxins can lead to cancer, birth defects and long-term health problems.
Along with Samantha Ladewig and Shaowu Bao of Coastal Carolina University, Chow is co-author of “Natural Fibers: A Missing Link to Chemical Pollution Dispersion in Aquatic Environments.” During his collaborative research, Chow has analyzed sand samples from more than a dozen beaches in the Southeast.
“Initially, we were looking for the microplastic materials, but we also found natural fibers – and not just near wastewater discharge sites but in areas miles and miles away,” Chow said. “So we began to discuss where these fibers were coming from and we determined that they were originating from clothing. When we turned to scientific literature to broaden our knowledge, we found that many researchers were studying microplastics but that few if any were looking at the dispersals and effects of natural fibers. This prompted us to switch gears.”
Chow’s research on natural fibers is new and still developing. Many questions are yet to be fully answered. At what rate and magnitude are these fibers being exported into the ocean? At what scale are they absorbing and releasing pollutants? And to what degree are they hazardous to marine and terrestrial organisms?
“Researching synthetic materials and natural fibers together to understand the specifics of their roles will help fill the gaps in our knowledge,” Chow concluded. “This is truly a missing link in our understanding of how chemical pollutants are poisoning our aquatic environments. And it should not be taken lightly.”