PORTLAND, Ore. (KOIN) — People love to wear fleece jackets, sweat-wicking clothes and yoga pants. But a new study shows these items are contributing to microplastics being found in Pacific oysters and razor clams.

The oysters and razor clams, which are important to Oregon and to its economy, have been found to have microplastic pieces from all 15 sample sites taken during the study along the Oregon coast during spring and summer 2017. On average, 11 microplastic pieces were found in oysters and 9 in clams, the PSU study said, and almost all of them were microfibers.

Out of 300 samples taken, microplastics were found in 298. There were more microplastics in spring oysters than summer oysters.

So how do the microfibers get from your yoga pants to the oysters and clams? Laundry.

“These microfilaments can be shed from clothing, up to 700,000 per load of laundry,” said Britta Baechler, a Ph.D student at PSU. “Those particles then travel out through greywater into wastewater and to the coast.”

Elise Granek, a professor of environmental science and management at PSU, said the microplastics were found regardless of whether “it was a fairly urban site or a rural site, estuary or open-coast beach.”

Fisheries and oyster growers are often blamed for microplastics in seafood. But Granek said there’s no scientific consensus that’s true.

“We’re all using plastics on a daily basis. We are all the source of contamination in our seafood. And microplastics are not just in our seafood. We know that they are in our beer, in our salt, in our drinking water,” she said in a statement released by PSU.

Even though this PSU study shows the microplastics come from our clothes, it’s still unclear what effect it has on the oysters, clams and people who consume them.

“If reproduction or growth is impaired, that could really affect not just individual clams or oysters, but possibly local populations of these organisms as well,” Baechler said.

“Although we think of the Oregon coast as a much more pristine coastline compared to California, Puget Sound or the Eastern Seaboard,” Granek said, “when we are talking about microplastics, we’re still seeing that human footprint on even our more pristine coastline.”

The research by Granek and Baechler was supported by the Oregon Sea Grant and included help from Matthew Hunter from the Oregon Department of Fish and Wildlife and Kathleen Conn from the U.S. Geological Survey.

Their findings were published in the journal Limnology and Oceanography Letters.