 It's Living on Earth. I'm Ainsley O'Neill. And I'm Jenny Doering. The 85-mile stretch of the Mississippi River between Baton Rouge and New Orleans is known as Cancer Alley because communities there experience the highest risk of cancer from industrial air pollution in the United States. And a major source of that risk comes from facilities that emit ethylene oxide, a colorless, sweet-smelling gas used in sterilizing medical equipment.