Scientists gather to study risk from microplastic pollution

In this Feb. 19, 2020 photo, vials that are part of an experiment on tire particle exposure concentrations sit on a counter at a research lab at Oregon State University. Scientists are finding "microplastics" - incredibly tiny bits of broken-down plastic smaller than a fraction of a grain of rice - everywhere in the environment, from ocean water to inside the guts of fish and even mixed in with the poop of sea otters and giant killer whales. (Oregon State University via AP)

In this Feb. 19, 2020 photo, micro-plastic particles from rubber tires are seen under a microscope in this image taken in a research lab at Oregon State University. Scientists are finding "microplastics" - incredibly tiny bits of broken-down plastic smaller than a fraction of a grain of rice - everywhere in the environment. (Oregon State University via AP)

This 2013 photo from the National Oceanic and Atmospheric Administration (NOAA) shows piece of microplastic foam debris found along the coast of Alaska, on a person's finger. Scientists are finding "microplastics" - incredibly tiny bits of broken-down plastic smaller than a fraction of a grain of rice - everywhere in the environment, from ocean water to inside the guts of fish and even mixed in with the poop of sea otters and giant killer whales. Dozens of scientists from around the U.S. West will attend a gathering this week in Bremerton, Wash., to better focus the research on the environmental threat. (NOAA via AP)

In this Feb. 19, 2020 photo, a tiny mysid shrimp is seen under a microscope at a research lab at Oregon State University. Scientists are finding "microplastics" - incredibly tiny bits of broken-down plastic smaller than a fraction of a grain of rice - everywhere in the environment, from ocean water to inside the guts of fish and even mixed in with the poop of sea otters and giant killer whales. Dozens of scientists from around the U.S. West will attend a gathering this week in Bremerton, Wash., to better focus the research on the environmental threat. (Oregon State University via AP)

In this August 2017 photo, Alice Zhu, with the University of Toronto, prepares to take a sample of water from San Francisco Bay. The San Francisco Estuary Institute found microplastics in stormwater runoff entering the Pacific Ocean in a three-year study completed in 2019. (Shira Bezalel/San Francisco Estuary Institute via AP)

FILE - This May 19, 2010, file photo shows a blue rectangular piece of microplastic on the finger of a researcher with the University of Washington-Tacoma environmental science program, after it was found in debris collected from the Thea Foss Waterway, in Tacoma, Wash. Tiny bits of broken-down plastic smaller than a fraction of a grain of rice are turning up everywhere in oceans, from the water to the guts of fish and the poop of sea otters and giant killer whales. Yet little is known about the effects of these "microplastics" - on sea creatures or humans. (AP Photo/Ted S. Warren, File)

PORTLAND, Ore. — Tiny bits of broken-down plastic smaller than a fraction of a grain of rice are turning up everywhere in oceans, from the water to the guts of fish and the poop of sea otters and giant killer whales.