Carried by tides and currents, more microplastics have traveled north and made their way into Arctic ice than ever before, scientists have discovered.

Researchers from the Alfred Wegener Institute in Germany analyzed ice core samples taken from across the Arctic Ocean and found that today’s Arctic ice contains two to three times as many microplastics as samples from previous years, according to one study.

Take Action: Call on Governments and Business Leaders to Say No to Single-Use Plastics

The Ocean Conservancy estimates that approximately 8 million tons of plastic waste end up in the ocean every year at the rate of roughly one garbage truck-load per minute. And as those plastics degrade, tiny plastic particles less than five millimeters long splinter off, posing a potentially a massive threat to marine life. Microplastics also include small pieces of plastic like the microbeads found in many soaps and cosmetics, which several cities and countries have now banned.

The scientists found a total of 17 different types of plastic in the ice samples and traced many of the microplastics back to “Great Pacific Garbage Patch” — the massive island of garbage in the Pacific Ocean, which is now three times the size of France. However, the researchers also found substantial traces of nylon and paint in the ice, which point to increased shipping and fishing activity in the Arctic region.

Read more: That Massive Ocean Garbage Patch Is About to Be Cleaned Up

Though many of the plastic particles have traveled a long way north to end up in the Arctic ice, they won’t stay there.

As climate change causes sea temperatures to rise, the ice will eventually melt, sending the microplastics back into the water, where sea creatures are likely to unwittingly consume it. And once it makes its way all the way up the food chain, so will humans.

Humans are already unavoidably ingesting about 70,000 microplastics every year, and microplastics have been found in 93% of bottled waters. While the specific effects of ingesting microplastics on humans and marine life is still uncertain, plastic becomes a “magnet for pollutants” when in the water, according to the United Nations Food and Agriculture Organization.

“I think that evidence is increasing that microplastics have detrimental effects in many cases, such as reduced feeding rates, reduced growth rates, immunological stress, lowered reproductive rates, behavioral changes, decreased fecundity and sometimes mortality,” Melanie Bergmann, one of the study’s authors, told Newsweek. “When we eat fish, or especially animals that we consume as a whole—such as mussels—humans may also consume microplastics and the associated toxins.”

Read more: Your Water Probably Has Plastic In It. Here’s What You Can Do About It

Unfortunately, the microplastic issue isn’t one that will simply resolve itself over time. People will need to curb their plastic use, step up their recycling habits, and stem plastic production.

“If we don't turn off the tap and decrease plastic production, the problem will increase,” Bergmann said.

Global Citizen campaigns to protect the environment and oceans. You can take action here to help reduce the amount of plastic that ends up in the sea by calling on governments and business leaders to say “no” to single-use plastics.