In Dunn County, North Dakota, the roads can kill you. In fact, anything you do to disturb rocks in the area, like driving or even sweeping, can kick up naturally-occurring particles that lodge in your body and give you a rare kind of lung cancer up to 30 years later. Dunn County, you see, is home to a lot of rocks containing erionite, an asbestos-like substance that’s highly toxic. Unfortunately, nobody knew that until very recently. And so at least 300 miles of roads in North Dakota are paved with the stuff. More »