Read the full story from NPR.
Western Pennsylvania’s steel industry may be a shell of what once was. But the Clairton works, about 20 miles south of Pittsburgh, remains North America’s largest producer of coke, a key component in making steel. Coke is basically pure carbon, made from baking coal at high temperatures, a process that can create a lot of pollution.
On this day the fumes aren’t too bad, owing to rain that has just come through. But on some days the rotten egg odor of sulfur is inescapable, a rich, earthy smell that sticks to the back of the throat.