"Plastic trash is littering the land and fouling rivers and oceans. But what we can see is only a small fraction of what's out there.
Since modern plastic was first mass-produced, 8 billion tons have been manufactured. And when it's thrown away, it doesn't just disappear. Much of it crumbles into small pieces.
Scientists call the tiny pieces "microplastics" and define them as objects smaller than 5 millimeters — about the size of one of the letters on a computer keyboard. Researchers started to pay serious attention to microplastics in the environment about 15 years ago. They're in oceans, rivers and lakes. They're also in soil. Recent research in Germany found that fertilizer made from composted household waste contains microplastics."