The Grand Canyon is vast and magnificently unsubtle: The 277-mile gash has long humbled visitors with its sheer rock walls and the river ribboning below. The landscape is also cloaked with something much, much smaller, but just as humbling. A team of researchers has found that the Grand Canyon—along with 10 other protected patches of the United States—is lousy with microplastics. Plastics more famously menace the watery parts of the world. In the oceans, ghostly plastic bags ensnare corals and little chunks swirl in small eddies and much wider gyres,…
