Prior to the passage of the Clean Air Act, the US had some serious air pollution problems. This is what LA looked like in 1948.
There were many days when you could hardly see across the Grand Canyon, because of smoke from coal fired power plants. Government solved those problems through regulations passed in the 1960’s and 1970’s.
Unfortunately, those same government agencies have outlived their usefulness, and are now regulating imaginary pollution. The EPA is obsessed with CO2, which is not a pollutant.
The EPA needs to be defunded, because they are now hurting America rather than helping. Much of the Federal government has become a malignacy, which exists only for its own benefit.