Scientists have been telling us in recent years that tiny bits of plastic are showing up more often in our lakes and oceans.
Now a new study says those microplastics are in most of our tap water, too. They were in 94 percent of the samples from around the U.S analyzed by a University of Minnesota researcher and other experts.
They're not sure yet what this means for the health of people (or of fish, animals, and oceans) but some experts worry it's a bad sign.
The new project was put together by a nonprofit news organization called Orb Media. They worked with researchers from the U of M and the State University of New York on their new report called Invisibles: The Plastic Inside Us.
What did they find?
They tested tap water in more than 150 cities and towns across five different continents.
Altogether, 83 percent of the water samples tested positive for microplastics. Here's their breakdown from around the world:
Some pretty all-American places have plastic in their water, the study found. The U.S. Capitol, the Trump Grill in New York, even the headquarters of the Environmental Protection Agency all had microplastics coming out of the taps.
While we knew these particles were in lakes and oceans, finding them in our tap water does raise the stakes some. For one thing, it means they're also in a lot of our food, the report points out. Most bread, pasta, soup, and baby formula are all likely to have a little bit of plastic in them.
What are these particles?
Here are two important things to know about plastic: it's all around us and it's more or less indestructible.
Plastic is used in lots of things people make. Your cell phone, your shoes, most of your clothes, your contact lenses – all of them have some plastic in them.
While an apple core or orange peel eventually breaks down and returns to the earth, plastic doesn't ever fully disappear, the Orb Media report says. It just breaks down into smaller and smaller pieces, some as tiny as a nanometer.
So particles that come off our clothes, shoes, or carpets eventually get washed down a drain. One thing the new study confirms is our water treatment plants don't filter them out, so plastics pass right into our drinking water.
According to Orb Media's report, no one knows of a way to filter microplastics out of water.
Is this bad for us?
The short answer is we don't know what the effects of these plastic fibers are. But some scientists are concerned it could be bad.
The report says there's evidence the plastic bits soak up toxic chemicals in the water – and then release them when they're ingested by a fish or mammal. When they're inside a human, some microplastics are small enough to pass right through intestinal walls into body organs.
So one priority for scientists right now is to learn more about these things.
Microplastics big enough that you can see them (about a millimeter long) are floating on Lake Superior, according to Minnesota Sea Grant, which is monitoring them.