We have grown accustomed to hearing about how plastic is damaging the environment, but a new threat has been identified in the form of microfibres: microscopic plastic fibers that wash away from clothing when it is laundered.
Global plastic production in 2015 was estimated at 322 million metric tonnes, most of it in the form of cheap, disposable items that, due to the nature of plastics —they don’t biodegrade like organic materials but only break down into smaller and smaller (but still plastic) particles— are building up in considerable quantities in the world’s oceans and marine life. By the year 2050, experts say the oceans will contain more plastic by volume than fish.
One form of microplastic that has received a lot of attention is the microbead, those tiny (less than 5mm in size) fragments added to health and cosmetic products like toothpastes and facial scrubs for their exfoliating effects. Too small to be filtered by most sewage treatment plants, they end up in rivers, lakes and oceans where they get ingested by fish and other aquatic creatures. With growing public awareness over the past few years of the ecological damage, governments as well as the companies making the products have begun to take action to curb the use of microbeads. This past November, for example, the Canadian government announced a phased-in ban of products containing microbeads, starting in July 2018.
But microbeads are now just the tip of the microplastic iceberg, as scientists are revealing in more and more detail the far more destructive power of microfibres. Found in fleece clothing and athletic wear such as yoga pants, microfibres get released into sewage systems when the garments are washed —one study found that each microfibre item such as a fleece jacket releases an average of 1.7 grams of microfibres with each wash, with about 40 per cent of that plastic making it past wastewater treatment plants and ending up in rivers, lakes and oceans.
Now, a study from the Institute of Environmental Science at Carleton University has highlighted the impact of microfibres on Canadian waterways, measuring the concentration of microplastics in the Ottawa River and its tributaries and finding that while microbeads were identified in five per cent of the water samples analyzed, plastic microfibres were found in 95 per cent of the samples.
“The most common form of plastic particles found was microfibers,” say the study’s authors. “These made up between 70% and 100% of all plastic particles observed, although plastic microbeads and secondary plastic fragments were also recovered.”
The researchers note that while microplastic pollution in ocean environments has been well observed, there is still a lot left unknown about its concentration, distribution and effect on freshwater ecosystems. The team not only detected plastic fragments in all its surface water samples but in 80 per cent of its tap water samples as well, although in lower concentrations.
“Our study has shown that plastic pollution of the Ottawa River and its major tributaries in Canada’s National Capital Region is prevalent and at concentrations greater than have been reported for many other freshwater systems including the Great Lakes,” say the study’s authors, whose research is published in the journal Facets.