Polyester and other synthetic fabrics are invisible, but huge, pollutants. We have all seen photos of (or experienced firsthand) the effects of pollution in the ocean: plastic straws waving in kelp forests, fish and seagulls tangled in six-pack rings, clear plastic bags shadowing a bloom of jellyfish. And while the effect of synthetic fabrics on the environment is less obvious, it is more insidious.

Polyester fabric has boomed since its development in 1941, and synthetics have since become the most common fabrics for clothing in the United States. Currently about 65 percent of all fabrics produced are synthetics such as polyester, acrylic, and nylon, and polyester accounts for most of it. It’s the preference of many manufacturers and some consumers because it is both durable and cheap. However, its environmental cost is also rising due to the huge amounts we produce and consume.

When you wear and wash synthetic clothes, very small pieces of thread and fibers shed from the garment. If clothing is made with a natural fabric, those microfibers, as they are called, fall off to degrade and become dust. But with synthetic fabrics, those microfibers are tiny pieces of plastic that wash away in the water and eventually flow into the ocean, where animals ingest them. Recent studies show that, even in ocean trenches, animals are ingesting plastic. A 2019 study found fibers “within every trench,” including the Marianas Trench, and inside “84 percent of amphipods” tested. These microfibers come back to bite us as they move up the food chain.

Marine biologist Alan Jamieson explains that amphipods, which are small crustaceans usually less than a half-inch long, will “eat pretty much anything” because “food is scarce in the deep.” Additionally, Jamieson explains that “everything else eats amphipods—shrimp, fish—and they’ll end up consuming plastics, too. And when fish die, they get consumed by amphipods, and it goes round and round in circles.”

Unfortunately, we are part of that circle, and we are eating that plastic as well. A separate study in 2018 found that 73 percent of fish in the Northwest Atlantic have ingested plastics, a much higher amount than previous studies, which used a different method that did not detect the smallest of microfibers. Plastic being plastic, rather than degrading, it just breaks into smaller and smaller pieces. It might be possible to avoid microfibers if we could extract a fish’s digestive system, but in 2008, scientist Mark Browne found that microplastics can be absorbed into the circulatory system and found inside blood cells.

Tap water, sea salt, and beer have all tested positive for microfibers, as well, and a 2018 study estimated that the average person ingests 5,000 pieces of microplastic every year from tap water alone. Scientists don’t yet know what the consequences of ingesting plastic will be—for fish or for humans. According to a 2011 study published in Environmental Science Technology, “Ingestion of microplastic provides a potential pathway for the transfer of pollutants, monomers, and plastic-additives to organisms with uncertain consequences for their health.”

Besides casting ballots, you can also effect change with your bills by buying less synthetic clothing or buying secondhand. Cotton, linen, silk, and wool are often more expensive than synthetic fabrics, but can be found in abundance in thrift stores, resale shops, and vintage boutiques. And, while cotton is a natural product that doesn’t shed synthetic fibers, it does require a lot of water to produce, so shopping secondhand is all the more important for the environment. By buying synthetic fibers at a thrift store, you are using fibers that already exist in the world and thus discouraging the production of more of them. 

Another easy way to help the environment is just to wash your synthetic clothes less often so that fewer fibers come off in the water. Try taking your work or play clothes off at the end of the day and hanging them up to air while you change into some comfy cotton PJs. The Plastic Pollution Coalition also recommends washing your clothes in cold water with liquid detergent. This is less abrasive to your clothing, which not only makes your items last longer, but also scrapes off fewer fibers in the wash. Of course, the best thing to do is just get creative with the clothes you already have. Check out some slow-fashion “shop your closet” videos for some great remixing ideas that are easy on the environment and your wallet. Crustaceans, fish, and future generations will appreciate it!