Listening practice: The tiny plastic pieces that travel everywhere

Imagine holding a clear glass of water under a bright window. The water looks clean. You cannot see a storm, a factory, or a floating bottle. Yet scientists now ask a harder question: could tiny pieces of plastic be moving through this ordinary scene? According to the U.S. National Oceanic and Atmospheric Administration, microplastics are plastic pieces less than five millimeters long, about the size of a pencil eraser or smaller. Some are made small from the beginning, such as microbeads once used in personal care products. Many others begin as larger plastic objects and slowly break into smaller fragments.