The air and water quality in the US used to be awful. Cities were choked with smog. The plume from the Four Corners Power Plant in New Mexico was the most visible man made feature for Apollo astronauts. The Cuyahoga River near Cleveland caught on fire in 1969.
Rowan and Martin’s Laugh In had a joke that Lake Erie was so filthy because of all the dead fish. It used to be difficult to see all the way across the Grand Canyon, because of particulates coming out of the Navajo Generating Station. It used to be difficult to see across the Rio Grande Valley north of Santa Fe, New Mexico – because of particulates coming out of the Four Corners Power Plant.
Things are much better now because of government regulations. There was a time when government environmental policy was sane, and they focused on actual pollutants.