Smog Disaster in Donora, Pennsylvania

Throughout the first half of the twentieth century, the town of Donora, located on the Monongahela River in Pennsylvania, was one of America’s major steel mill towns and home to the American Steel & Wire Company and the Donora Zinc Works plants, both of which were run by the United States Steel Company. Starting on October 26, 1948, a thick, acrid smog covered the Donora valley for several days due to a weather inversion, in which a layer of warm air prevented the mills’ cold poisonous emissions to rise into the atmosphere. As a result, a dense, polluted fog stayed close to the ground. As Donora’s residents inhaled the poisonous chemicals trapped inside the smog, more than 7000 people suffered respiratory distress. The deaths of 20 people were blamed on the smog. Donora gained major national attention, for it revealed the severe effects of industrial air pollution on public health. The incident led to a series of clean air regulations and culminated in the US Clean Air Act of 1970.

Further Readings: 
  • Davis, Devra. When Smoke Ran Like Water: Tales of Environmental Deception and the Battle Against Pollution. New York: Basic Books, 2002.
  • Uekoetter, Frank. The Age of Smoke. Environmental Policy in Germany and the United States, 1880-1970. University of Pittsburgh Press: Pittsburgh, 2009.