It wasn't as big a problem as it is now, but in the past coal was used primarily for energy purposes and there were no air quality regulations. Enviropedia.org (not the same as Wikipedia) mentions early air pollution in the UK resulting mainly from coal burning. The main energy source of the Industrial Revolution came from coal and was used to power factories and homes. As learned in class, charcoal can release dirty particles into the air, which is why it is not used as often. Countless air pollution disasters have occurred, especially in America. Not long ago in Donora, Pennsylvania, in October 1948, there was a smog “invasion” of the town that caused 20 deaths and infected thousands more. Smog is defined as “fog or haze combined with smoke and other air pollutants.” Contributing to this disaster was the city's steel and zinc mill, which constantly emitted toxic smoke. - Figure 1. Shows fog in the streets of Donora, Pennsylvania, faced during the smog of 1948. (Washington Post,