MICROPLASTICS: What are they and how can we reduce their prevalence in the oceans?
Microplastics are very small plastic particles (<5mm) found in increasing amounts in all the world’s oceans and shorelines, even found in Arctic and Antarctic ice. The major sources are:
- Tiny polyethylene granules used as ‘scrubbers’ or ‘exfolients’, found in facial cleansers, soaps and toothpaste (now banned in Canada, the U.S., and the U.K.) and household, boat, and industrial cleaning products.
- Resin pellets, the size of a grain of rice, called nurdles. They are the raw material for nearly all of our plastic products. Many get spilled from factory drains or during transportation.
- Larger plastic items, which eventually degrade into microplastics.
- Our synthetic clothing, bedding and towels, which release millions of tiny plastic fibres, about one-fifth the diameter of a human hair, in wash water. These microfibres escape most wastewater treatment facilities and end up on shorelines and in the ocean.
Microplastics greatly outnumber bigger fragments of plastic in the oceans. A study conducted in 2014 estimated that more than 5 trillion pieces of plastic weighing 269,000 metric tons were floating in the oceans. 92% of these were microplastics. Sadly, their small size makes them virtually impossible to clean up.
Because of their small size, microfibres can be ingested by marine organisms, from zooplankton to whales, working their way up the food chain to molluscs, crustaceans, fish, birds, marine mammals and ultimately to humans. Microplastics have larger surface area to volume ratios than larger pieces of plastic, making them (volume to volume) more effective at picking up and transferring toxins found in water to the organisms that ingest them.
In various places in the world, microplastics have been found in tap water, bottled water, sea salt, beer, honey, sugar, and even the air we breathe. In the UK, researchers found plastic particles in a third of fish. Not surprisingly, a recent study from Austria found microplastics in human stools. It is not yet clear how plastics are affecting organisms, food safety, and human health.
How contaminated is the Salish sea in Canada?
Dr. Peter Ross, Executive Director of Ocean Wise’s Coastal Ocean Research Institute, is leading research on microplastics. In 2017, his team found up to 25,000 plastic particles and fibres in just one cubic metre of water off the coast near Vancouver and, in the Strait of Georgia, an average of 3,200 plastic particles per cubic metre. Juvenile salmon along the B.C. coast are ingesting between two and seven microplastic particles each day, while returning adult salmon are taking in as many as 90 per day. Dr. Sarah Dudas, a researcher at Vancouver Island University’s Nanaimo campus, found an average of eight microplastic particles in wild and farmed Manilla clams and oysters.
Ross noted that washing a synthetic sweater releases up to 10,000 microfibres, and a fleece jacket, made from recycled plastic bottles, up to a million microfibres, into the sewage system. Ross is currently working with Metro Vancouver and sewage treatment plants testing incoming and outgoing water for microplastics and trying to determine what measures might stop the flow into the ocean. Hopefully this work will culminate in improved filtering techniques at plants. Mountain Equipment Co-op, Arc’teryx and the American companies Patagonia and REI are all supporting Ross’s research. Other research is targeting changes in fabric construction to reduce fibre shedding.
While researchers, governments and industry look for solutions to the microfibre problem, what can you do? Here are some suggestions about what you can do to help:
- Buy only what you need and buy high quality. Cheap fast fashion clothes don’t last and shed more fibres.
- Buy clothes made from natural fibres such as wool or cotton and press clothing companies to provide more options in natural fibres. While these materials shed fibres, they will eventually biodegrade. Plastic won’t.
- Wash your synthetic gear less often and for shorter duration. You can spot clean dirt and many stains.
- Invest in a front-load washer when your current washer breaks down. Top-loading machines cause seven times more shedding than front loaders.
- Use a cooler wash temperature. High temperatures break down clothes and release more fibres.
- Avoid using laundry powder as its scrubbing action loosens more microfibers than liquid soap.
- Use a filter bag or install a filter on your washing machine. You put your synthetic clothes into the bag before washing (e.g. the Guppy Friend which costs around $25). A washing machine filter costs about $140 and will catch the most microfibres.
By Susan Hannon and Michelle Mech, members of Salt Spring Island’s SUPER (Single Use Plastic Elimination and Recycling) task force.