Doing laundry isn’t something most of us enjoy doing. And now the evidence is clear that the world’s aquatic animals don’t enjoy it either. It turns out that clothes made from synthetic fibers shed tiny plastic microfibers in every wash. This fibrous debris goes from your washing machine, through the municipal sewage system and ends up in all sorts of waterways—marine, coastal and freshwater—where the tiny fibers are ingested by fish, crabs and other aquatic wildlife. In turn, many of these animals end up in our food supply—and on our dinner plates. It seems we are slowly, and literally, eating the shirts off our backs.

A host of recent studies have sounded alarm bells. One frightening conclusion is that these microfibers—a subcategory of microplastics—are even more pervasive in the environment than microbeads, tiny plastic beads common in beauty products that were recently banned in the United States.

One of first researchers to lift the veil on this environmental crisis was ecologist Mark Browne. In 2011, Browne, now a senior research associate at the University of New South Wales in Australia, published a paper in the journal Environmental Science and Technology that concluded microfibers from synthetic fabrics like nylon and acrylic make up 85 percent of human-made debris across the world’s shorelines. The vast majority of that synthetic waste is being released from clothing when it’s washed in laundry machines.

Browne’s experiments were eye-opening. He sampled wastewater from domestic washing machines and found that just one piece of clothing can release nearly 2,000 individual microfibers in a single wash. “As the human population grows and people use more synthetic textiles, contamination of habitats and animals by microplastic is likely to increase,” Browne concluded.

After he published his research, Browne reached out to several leading apparel companies, including Patagonia, Nike and Polartec, in the hopes of forging a collaboration to determine the exact movement of these microfibers—from clothing to oceans—and to develop a more sustainable textile design to stop the crisis from growing. His vision, which he presented in 2013, is called Benign by Design, a program supported by a number of scientists and engineers from academic institutions around the world, including the Environmental Protection Agency. Benign by Design, according to its website, “disrupts the current unsustainable pattern by showing companies exactly how textile wear leads to fiber pollution and ways to control their emissions.”

But the companies Browne approached weren’t interested in supporting his idea. “Perhaps it’s my pitch,” Browne told the Guardian. “We want to look for new, more durable materials that do not emit so much microplastic.” Only one firm, Eileen Fisher, accepted his proposal, giving him $10,000 to support his work.

“Any lifecycle issue, especially when it’s about a huge consumer product like clothing, is important,” Shona Quinn, sustainability leader at Eileen Fisher, told the Guardian. “[Browne] is raising an issue no one else has been studying.” Alas, Eileen Fisher isn’t a main source of the problem: 90 percent of its clothing is made from natural textiles. Still, receiving the funding was validation of Browne’s work.

Then, in an ironic twist, Patagonia itself validated Browne’s work when a study it funded that was conducted by researchers at the Bren School of Environmental Science and Management at UC Santa Barbara was released in June. The researchers analyzed water and sediment samples from around the world and concluded that, indeed, “microfibers are ubiquitous in aquatic environments.” They also analyzed the wash cycles of four different types of synthetic Patagonia jackets (and one budget fleece jacket for comparison).

Here are some of the details of what they found:

Finished apparel products contain large quantities of chemical substances… many of which are released from garments during consumer washing. This indicates that microfibers are of particular concern regarding their potential to transport hazardous chemicals into the environment.

Wastewater treatment plants (WWTPs) receive large amounts of microfibers daily.

While most of these microfibers are removed, a significant amount is still released into the local environment.

Aquatic organisms throughout the food chain consume microplastics and microfibers both directly and indirectly.

Within the food chain, these particles have been found to cause physical and chemical impacts, resulting in starvation and reproductive consequences in species.

Synthetic fleece jackets release an average of 1.7 grams of microfibers with every wash.

Older synthetic fleece jackets shed nearly two times the amount of microfiber than new ones.

Curiously, the Patagonia study found that top-loading washing machines had more than five times the microfiber shedding than front-loading machine in their trials.

The UCSB researchers also noted that, while the main focus of the microfiber pollution research has been on aquatic ecosystems, terrestrial ecosystems are not immune. “It's increasingly common to apply sewage sludge to agricultural fields so more fibers are being found on land,” they noted.

And there’s more irony. In an effort to reduce waste, Patagonia and other outdoor apparel companies use tiny plastic fibers taken from recycled plastic bottles in their products, to prevent those bottles from ending up in landfills or the ocean. However, as all this research is making clear, this good-intentioned strategy may actually be worse for the environment than leaving those plastic bottles intact. They’ll end up in the ocean anyway, in bits small enough for animals to ingest.

Knowing that aquatic wildlife eat these microfibers is one thing; but seeing the impact on an individual fish brings this crisis to life—or rather, death. Sherri Mason is a professor of environmental chemistry at the State University of New York at Fredonia. She's an expert in plastic pollution, having studied its impact on the Great Lakes ecosystem for several years. But as Leah Messinger recently reported in the Guardian, the first time Mason cut open a fish from the Great Lakes, “she was alarmed at what she found.” The body cavity of the fish was filled with synthetic fibers. Mason said that looking through a microscope, they seemed to be “weaving themselves into the gastrointestinal tract.”

This problem is pervasive and not going away anytime soon. Abigail Barrows is the principal investigator of the Global Microplastics Initiative, part of Adventurers and Scientists for Conservation, a nonprofit research organization based in Bozeman, Montana. After processing nearly 2,000 aquatic samples covering both freshwater and marine ecosystems, she came to a similar grim conclusion: Microfibers represent about 90 percent of the debris found in aquatic environments.

What's more, recent research has shown that the ingestion of microfibers by wildlife is even worse than previously thought. In 2014, researchers at the University of Exeter in England studied the impact of microplastics on crabs. What they found was extremely concerning. Crabs don’t just ingest microplastics through their mouths; microplastics also enter their bodies through their gills. This discovery was unexpected, and it has serious ramifications not just for the poor, unwitting crabs, but other crustaceans, molluscs and fish—really any animal who has a gill-like structure used for exchanging gases.

This is also bad news for the humans who eat these species. “This is highly important from an ecological point of view, as if these plastics are retained longer within the animal there is more chance of them being passed up the food chain," said Andrew Watts, the study's lead author.

Since aquatic animals ingest these microfibers, and humans ingest those aquatic animals, people whose diet includes fish and crustaceans are likely also ingesting these tiny plastic bits. The UCSB researchers concluded, “Microplastics and microfibers have also been found in marine species directly consumed by humans, the effects of which are unknown.” Their findings just confirmed what Mason and her colleagues have known for years. After her 2012 pollution survey of the Great Lakes, she raised the food chain warning flag: “The world is an interconnected system,” she said. “This is not just about aquatic animals; it is a significant concern to human health as well.”

Gregg Treinish, founder and executive director of Adventurers and Scientists for Conservation, which oversees Barrows' microfiber research, said because of these studies, he has eliminated aquatic animals from his diet.

“I don’t want to have eaten fish for 50 years and then say, ‘Oh, whoops’,” he told the Guardian. But avoiding seafood may not exclude one from harm. The UCSB researchers also detected microplastics in non-animal, marine-sourced food products like sea salt. So, even vegetarians and vegans could be impacted.

In addition to eating animals that contain microplastics, there’s another potential health concern with synthetic clothing, and that is the various toxic chemicals they might contain, such as formaldehyde, brominated flame retardants (PBDEs) and perfluorinated chemicals like Teflon.

Formaldehyde, which the EPA lists as a “probable human carcinogen,” is released by some textile finishes, particularly those that are meant to be wrinkle-resistant, while the garment is new. (That's one reason always to wash new clothing before wearing it.) PBDEs are no better, with the Washington Post reporting that they have been linked to “thyroid disruption, memory and learning problems, delayed mental and physical development, lower IQ, advanced puberty and reduced fertility.”

The National Institutes of Health says that some perfluorinated chemicals like Teflon—which are sometimes added to clothing to make them waterproof—“disrupt normal endocrine activity; reduce immune function; cause adverse effects on multiple organs, including the liver and pancreas; and cause developmental problems.” Some of these toxic chemicals are bioaccumulative, so even if you absorb tiny amounts through your skin on a daily basis, after many years, a health impact might arise.

So what can be done? One solution would be to update filters at municipal WWTPs so they can catch microfibers before they are released into waterways. But this is cost-prohibitive. As the UCSB researchers write, “Due to the high capital costs of WWTPs, upgrading WWTPs is not a feasible solution to microfiber pollution in the short term.”

Another solution would be to modify washing machines. The Rozalia Project, a nonprofit ocean conservancy group, has developed what it describes as “the world’s first consumer solution to stop microfiber pollution.” Its patent-pending "microfiber catcher"—a grapefruit-sized ball you can simply throw into your washing machine—collects microfibers that your clothes shed during the wash cycle to prevent them from escaping with the drain water.

But updating the world’s washing machines is a tall order. As Jill Notini, vice president of communications and marketing for the Association of Home Appliance Manufacturers, told the Guardian: “How do you possibly retrofit all of the units that are in the market and then add a filter in and talk to consumers and say, ‘Here is a new thing that you’re going to have to do with your clothes washer?’”

The best solution, then, is to attack the problem on the production side (i.e., make more sustainable textiles that don’t shed microfibers) and the consumer side (i.e., stop buying synthetic garments), simultaneously. It will take time to develop non-shedding synthetic textiles (and get all the main producers on board with the idea), but in the meantime, consumers need to be aware of the issue, because the problem isn’t going away, and it's just going to get worse. Until shed-free synthetics are available, choosing clothing made out of natural fibers like cotton is the best bet, for environmental and personal health.

“This is a human issue,” said Dr. Watts. “We have put this plastic there, mostly accidently, but it is our problem to solve. The best way to do this is to reduce our dependency on plastic. It comes back to the old phrase: reduce, reuse and recycle.” Just don’t recycle plastic bottles into synthetic fleece jackets.

[Editor's note: A previous version of this article incorrectly used the word "toxins." Toxins are poisonous substances produced by metabolic activities of a living organism. That is not the case with plastic microfibers. The error has been corrected to "toxic chemicals." Thank you to careful reader Judith S. Weis for pointing this out.]