Environmentalists have identified another threat to the planet. It’s called a nurdle.

Nurdles.
Source: Education Images/Citizens of the Planet/UIG via Getty Images

Nurdles are tiny pellets of plastic resin no bigger than a pencil eraser that manufacturers transform into packaging, plastic straws, water bottles and other typical targets of environmental action.

But the nurdles themselves are also a problem. Billions of them are lost from production and supply chains every year, spilling or washing into waterways. A U.K. environmental consultancy estimated last year that preproduction plastic pellets are...