Scientists are growing increasingly concerned about microplastics in water and in the food chain, but they face some daunting challenges in the race to uncover the sources of the problem.

"We're encountering a pollutant unlike any pollutant we've ever seen before," says Dr. Peter Ross, director of ocean pollution research at the Vancouver Aquarium. "This is not a chemical pollutant, it's a structural pollutant."

Recent samples his team have taken off the B.C. coast contained up to 25,000 plastic particles and fibres in just one cubic metre of water.

Yes, some of it comes from plastic bags, foam packaging, cigarette butts and other remnants of the millions of tonnes of plastic debris slowly breaking down in the world's oceans.

But there are some surprising sources, too, like laundry.

This water sample taken by researchers in B.C.'s Strait of Georgia contained an average of 3,200 plastic particles per cubic metre of ocean. Other samples off Vancouver contained up to 25,000 particles. (Vancouver Aquarium)

"A single sweater could release as much as 10,000 particles of microplastic fibres," said Ross.

"That's getting into the wastewater stream, and you have a million or two million people doing such laundry — it adds up."

Sewage treatment plants may hold answers

But no one knows yet how washing your favourite fleece jacket fits into the bigger picture.

To find out, Ross is working with sewage treatment plants to measure the number and types of fibres in the water coming in, and later sampling the treated water as it flows out into the Fraser River to compare.

What they find could lead to changes in filtering techniques at treatment plants.

Water sampling is also being done out in the open ocean, revealing a mix of fibres and other microplastics, defined as anything smaller than five millimetres in size.

It's a global issue, so everyone has an interest in reducing the amount of plastic being added to the world's waterways. One estimate puts it at the equivalent of a garbage truckload every minute. At this rate, by 2050 there will be more plastic in the ocean than fish.

To home in on the problem, technicians at the Vancouver Aquarium lab recently began using a $325,000 infrared spectrometer like the kind usually found in crime labs.

It can identify the type of plastic from tiny samples.

'It's not going to give us the exact fingerprint," says Ross. "It won't say 'Walmart fleece made in China,' but it will confirm it is plastic, give us the category, tell us about additives and sometimes actually a manufacturer."

MEC funding research

Vancouver-based Mountain Equipment Co-op has a long track record of trying to reduce the ecological footprint of its products.

Many in Canada's clothing industry worry that fleece, like this raw material at MEC's Vancouver test facility, could be a major source of microplastics. (Tristan Le Rudulier/CBC)

Jeff Crook, MEC's chief product officer says microplastics are on the radar of a number of outdoor speciality retailers including MEC and Patagonia.

The co-operative says it's leading Canadian efforts on the retail side to look for solutions.

"We can work upstream with manufacturers, as we've done in different periods of our history, to change the way things are made, either the materials going into them or construction, manufacturing methods."

Interviewed at the company's product testing lab, Crook said the world's multibillion-dollar textile industry likely can reduce its microplastic impact, but the lack of research to date means there's not yet a clear sense of how to go about it.

Vancouver Aquarium ocean pollution researcher Peter Ross is working with sewage treatment plants to measure the number and types of fibres in the water coming in. (Glen Kugelstadt/CBC)

To help find out, MEC is donating $50,000 to Ross's work on plastics. It's the first time the co-op has directly funded scientific research.

The federal Department of Fisheries and Oceans and various universities are also studying the issue.

'We don't know what the risk is'

It does seems as though textiles are a significant contributor to microplastics in the oceans.

At Vancouver Island University's Nanaimo campus, Dr. Sarah Dudas leads a team dissolving oyster guts in the name of science.

Her team harvested thousands of shellfish from multiple locations along the B.C. coast. They use chemicals to break down the organic materials, leaving behind microplastics, which are painstakingly filtered and counted.

We're finding fibres in almost every shellfish. - Sarah Dudas , Centre for Shellfish Research

"We're finding fibres in almost every shellfish," she says, holding up a piece of the filter paper she uses in her study.

When plankton and filter-feeding organisms ingest these plastics, it's a gateway into the food supply.

"We don't know what the risk is of microplastics from an ecosystem level or a human consumption level. We don't know a lot about how microplastics might affect food safety or food security," she says.

This microscopic image shows a tiny zooplankton tangled in a microplastic fibre. Plankton are part of the diet for some bigger fish, give the microplastics a gateway into the food supply. (Vancouver Aquarium) "We have our work cut out for us."

Vancouver Island oyster farmer Keith Reid puts about 12 million oysters onto dinner plates every year.

The owner of Odyssey Shellfish says he's supportive of the research.

"It's something as an industry we need to know," he says. "Are there microplastics in our oysters? And if there are, what levels are safe?"