As tiny bits of plastic build up in lakes and rivers, there’s a new suggestion that everyone has been wrong about where most of this plastic pollution comes from.
The common perception is that little round “beads” of plastic from skin care products and toothpaste are to blame.
But there’s now evidence that the real source is much simpler. It’s your laundry.
A new study of microscopic plastic in the Ottawa River pinpoints tiny synthetic fibres from clothing, says the study’s main author, Jesse Vermaire, an environmental scientist at Carleton University.
“I was surprised just how prevalent they are. When we first started looking for micro plastics we were looking for microbeads. We did see a few of those, like a few per cent. One to five per cent of all the plastics we found were microbeads but fibres were most of the plastics.”
Synthetic fibres made up 70 to 100 per cent of the plastic in various samples. The study by Carleton and Ottawa Riverkeeper is published this week in the online journal FACETS.
“That’s what they are also finding in the Great Lakes too, and sediment in the Great Lakes,” Vermaire said.
“Where they are coming from we’re not exactly sure, but other studies have shown they are from washing synthetic clothing — fleeces for example. (They) release hundred of fibres every time you wash them.”
The effects of microscopic plastic in water and sediment are still not well understood.
Most of the discussion in the past few years has focused on beads alone, Vermaire notes. “Government and industry have taken steps to reduce the number of those, to phase them out. That’s a good thing because there is no reason to have them in there anyway, so why introduce a plastic to the water?
“But these fibres, I think, would be much more difficult to control. If they are coming from clothing, that’s lot of different sources.”
The beads were in a range of personal care products ranging from some brands of toothpaste to exfoliating skin care products. The theory was that tiny bits of plastic would scour surfaces.
Vermaire’s group found that the Ottawa River has plastics in higher concentrations that the Great Lakes, but less than in many tributaries of the lakes, or in major U.S. Rivers. Vermaire describes microplastic in water as “ubiquitous.”
The concentration here is higher downstream from Ottawa’s sewage treatment plant than above it, strongly suggesting that plastic is washing down drains from the city.
Most appear red and blue, though it is also possible that light-coloured fibres are difficult to see under a microscope.