It's no secret that too many plastic products we use end up in the ocean. But you may not be aware of a major source of this pollution: our clothes.

Polyester, nylon, acrylic and other synthetic fibers – all of which are forms of plastic – now account for around 60% of the constituent material of our garments in the world. Synthetic plastic fibers are inexpensive and extremely versatile. They allow for stretching and breathability in your hobbies, as well as the warmth and sturdiness of winter clothing.

These fibers contribute to the plastic pollution of the oceans in a subtle but ubiquitous way: the fabrics that they manufacture, as well as the natural synthetic mixtures, penetrate into the environment by simple washing. Estimates vary, but it's possible that a single load of laundry releases hundreds of thousands of fibers from our clothes into the water.

And these tiny fibers – less than 5 millimeters long, with diameters measured in micrometers (one thousandth of a millimeter) – can eventually reach the ocean. There, they add to the microplastic pollution that accumulates in the food chain and is ingested by all kinds of marine animals, and even by us. Most of the plastic found in the ocean does not come in the form of whole products, like cups or straws, but rather shreds of plastic.

"Think of the number of people who wash their clothes every day and the number of clothes we all have," says Imogen Napper, a marine science scientist at the University of Plymouth, who co-authored a 2016 study on plastic fibers our clothes. "Even when we walk without washing our clothes, tiny fibers fall. It's everywhere."

Around the world, efforts are under way to reduce the use of some of the products found in the oceans, such as plastic cups and shopping bags. (Perhaps you have heard of plastic straw bans.) When we seek solutions to the general problem of plastic pollution, we must recognize that our clothes are an important part of the problem and will also need to be addressed. part of the solution.

Much of the problem of microplastics is a problem of plastic clothing

Consider the lint you collect in the dryer. These stuffed animals are bits of yarn from your clothes who have dislodged themselves and are caught by a sieve.

Similarly, synthetic fibers come off in the wash – but they are so small and there is no filter in the machines to catch them. Instead, these tiny plastic fibers are routed to the treatment plants, often without filters that are fine enough to recover them. (And if they do, the fibers may end up in another by-product of wastewater: fertilizers.) According to a 2011 study, treated wastewater is often dumped into rivers or the sea, carrying plastic fibers for clothing.

In 2016, Napper and a colleague designed a test to determine how much of this fiber could be washed away. They equipped a Whirlpool front-loading washing machine with a special filter to collect tiny fibers. They tested samples of three types of fabric: a polyester and cotton-blend t-shirt, a polyester hoodie, and an acrylic sweater. After a few washes (all clothes lose more when they are new), the acrylic fabric loses the most, followed by polyester, then poly-cotton blend.

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"We found that in a typical wash, 700,000 fibers could come off," said Napper. Other studies have resulted in different estimates. According to a 2011 article, 1,900 fibers could be released from a single synthetic garment during a wash; another effort estimated at 1 million fibers could be released by washing the polyester fleece.

It is difficult to determine the exact amount of plastic pollution per load because many variables can contribute to fiber loss: clothing structure, materials used, water temperature, type of detergent, fabric softener, degree of filling machine, etc. One study found that top-loading washing machines release seven times more microfibers than front-loaders.

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And even if the amount of plastic poured by loading is low, measured in milligrams, it adds up. A paper in Science and technology of the environment It is estimated that a population of 100,000 would produce about 1.02 kilograms of fiber each day. That's 793 pounds a year of tiny, individual plastic shards.

And a part of it will reach the ocean. "A lot of people will get caught in the sewage treatment plants, [but] even that small proportion that falls will soon accumulate, "says Napper. And once plastics are in the ocean environment, "there is no effective way to eliminate them."

These tiny particles of plastic can end up in the diets of marine life and accumulate throughout the food chain.

Microplastics can be toxic to wildlife, but they can also act as sponges, absorbing other toxins into the water. Worse, they can be ingested by all kinds of marine animals and accumulate in the food chain. A recent study found that about 73% of the fish caught in the ocean depths of northwestern Atlantic had microplastics in their stomachs.

"We know very little about the impact of microfibers on the health of animals and nonhumans," Ensia journalist Mary Catherine O'Connor recently explained in an excellent series on microfiber plastic pollution. "But what we do know suggests a need for additional research."

Apparently, scientists are discovering that plastic fibers contaminate the environment. Plastic textile fibers are often the main source of plastic pollution found in surveys. Plastic fibers have been found in beach sediments, mangroves and Arctic ice, even in the products we eat and drink. "The average person ingests more than 5,800 particles of synthetic debris" per year, a recent article published PLOS find. And most of these particles are plastic fibers.

A study conducted in 2017 on microplastic pollution on the shores of the Hudson River in the state of New York found that the river carries about 150 million microfibers of plastic in the Atlantic Ocean each day. It is unclear whether these fibers entered the river from sewage treatment plants or runoff or whether they float in the air, but, as Napper says, "It's everywhere".

It is difficult to say to what extent textile microplastics contribute to the general problem of plastic pollution in the ocean.

Microplastics are very tiny – and many of them are deep in the ocean – and it is difficult to get an accurate census. That said, a report published in 2017 by the International Union for the Conservation of Nature estimates that about 35% of microplastics introduced into the ocean come from synthetic textiles. He also emphasized how global the problem is: synthetic textiles are more prevalent in developing countries, which often do not have robust sewage treatment facilities to filter them.

Regardless of the exact proportion, "without a doubt," writes Flavia Salvador Cesa, a researcher in microplastics at the University of São Paulo, in an e-mail, "Fibers make a significant contribution to plastic pollution."

And remember: plastic can take hundreds of years, if not millennia, to degrade. The plastic we now throw into the ocean will remain for generations.

So what can we do about it?

It might seem that an easy solution to the problem of the plastic loss of our clothes: simply buy natural fibers or less clothes in general.

But being environmentally friendly should not be a luxury. Often, synthetic clothing is affordable clothing.

For a solution to be achievable, it "must be accessible to all," says Napper. Too often, an environmentally conscious consumer is a lucky person consumer. We can not expect everyone to buy stainless steel straws or glass water bottles. It is a message similar to that of deaf-class to insist that everyone should wear clothes made of organic cotton, wool or hemp (natural fabrics can also harm the environment, for example producing large quantities of water).

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Solutions must be more systemic. And they can start with our washing machines.

"Washing machines must be designed to reduce fiber emissions in the environment. for now, they are not, "says Mark Browne, an environmental scientist at University College Dublin, who found evidence of microfiber pollution from sewage treatment plants. Napper is currently working on a project to determine if fiber filters for washing machines are a feasible solution.

Textile manufacturers could also design less messy fabrics, clothing manufacturers could use them, and consumers could be more attentive.

"We still know little about how to minimize the environmental impacts of washing our clothes," said Cesa. However, there are two general recommendations for consumers: buy less clothing and "wash only when necessary".