There has been many air quality tradegies through the years that had many deaths and affected a lot of people. There was one in Meuse Valley, Belgium 1930. Coke ovens, steel mills, blast furnaces, zinc smelters, glass factories and sulfuric acid plants produced an estimated SO₂ concentration of 8 ppm. It was estimated that the SO₂ concentration was reached to 22,600 ug/m³. With in a few days, 600 people feell ill and 63 people died from it. In Donora, PA 1948 Effluents from a number of industries such as a sulfuric acid plant, a steel mill, and a zinc production plant became trapped in a shallow valley inversion to produce an unbreathable mixture of fog and pollution.6,000 became ill and there were 20 deaths. In London, England