Plastic pellets known as nurdles are polluting our waterways One of the biggest challenges facing the modern world is one most people don't know about and often can't even see. It's the problem presented by nurdles, trillions of small plastic pellets produced by petrochemical giants. Leftover pellets have been escaping into waterways and oceans for decades, but only lately has serious action been taken to figure out what can be done. That includes a monumental settlement in Texas, where Jeff Glor traveled to ground zero for this issue.