Air pollutant, usually white, grey, or black in appearance, that arises from combustion processes. Benjamin Franklin recognized that smoke was the product of inefficient combustion and argued that one should "burn one's own smoke." Smoke generally forms when there is insufficient oxygen to oxidize all the vaporized fuel to carbon dioxide, so much remains as carbon or soot. Smoke is largely soot, although it also contains small amounts of fly ash. Although domestic smoke and poorly constructed chimneys had long been annoying to city dwellers, it was the development of the steam engine that drew particular attention to the need to get rid of unwanted smoke. The first half of the nineteenth century witnessed an awakening interest on the part of local administrators in Europe and North America to combat the smoke problem.

Smoke has long been recognized as more than just an aesthetic nuisance. It has been proven to have a broad range of effects on human health and well-being. Early laws were preoccupied with reducing black smoke, and various tests and "smoke shades" were created to test the color of smoke in the atmosphere. For example, the Ringelmann Chart showed a set of shades on a card, which was compared to the color of smoke in the atmosphere. Today it has been shown that the color of suspended smoke particles in cities have gradually changed as coal is used less frequently as an energy source. In many cities the principal soiling agent in the air is now diesel smoke. Diesel smoke blackens buildings and even gets inside houses, and studies show that diesel smoke contains a range of carcinogens.

While in many of the major cities smoke production has been reduced, coal, peat, and wood continue to be burnt in large quantities. In these locations, often in developing countries, smoke control represents considerable challenge as environmental agencies remain underfunded.

See Also

Cigarette Smoke; Smog; Tobacco

Resources

Books

Brimblecombe, P. The Big Smoke. London: Methuen, 1987.