Definition, Cause, Effect & Prevention of Air Pollution

Written by shelly mcrae
  • Share
  • Tweet
  • Share
  • Pin
  • Email
Definition, Cause, Effect & Prevention of Air Pollution
The appearance of a brown cloud is evidence of photochemical smog. (Los Angeles Smog image by CanonXTiGuy from

The forces of nature and humankind's lack of knowledge created what has come to be known as the "Killer Fog" of 1952. As early as the 13th century, Londoners were burning coal to heat their homes. Later coal-burning factories were spewing sulphur dioxide, creating foggy air. In December 1952, a front of stagnant air settled over the city, trapping the sooty pollutants. John Nielsen, reporting for National Public Radio, called it "the deadliest environmental episode in recorded history." Some 12,000 Londoners may have died. This incident opened the eyes of the world to the dangers of air pollution.


Carbon monoxide and sulphur oxide are considered primary pollutants. These pollutants undergo chemical changes and cause secondary effects such as smog. Air pollution is defined by the existence and integration of toxic compounds in the atmosphere in concentrations high enough to cause harm to humans, animals and the Earth's environment.


Burning fossil fuels emits carbon monoxide and sulphur oxide. Automobiles, buses, planes and any form of gas-fuelled transportation emit carbon monoxide gases through exhaust systems. Sulphur dioxide is created through the burning of coal, and is associated with industrial waste. Manufacturing processes use coal for fuel, releasing sulphur dioxide into the air through the factory exhaust systems.


Air pollution is the source of smog, acid rain and possibly global warming. Smog is classified as either photochemical smog or industrial smog. Photochemical smog, often evidenced by the brown cloud hanging over densely populated cities, is created by the interaction of sunlight with molecules of primary pollutants. The resulting chemical reaction is toxic to humans and animals. Industrial smog is characterised by the grey-brown fog that hangs over industrial areas and is attributed to the interaction of sunlight, air molecules and sulphur dioxide. The result is, again, toxic air.


Individuals and businesses alike have taken steps to reduce their contributions to air pollution. Manufacturing and purchasing vehicles that use gas more efficiently and driving less, recycling to reduce landfills that emit toxic gases and patronising those businesses that reduce their industrial waste all aid in controlling air pollution. These actions, while laudable, act as a preventive only in reducing the amount of toxins spewed into the Earth's atmosphere.

Prevention / Solution

Air pollution may be prevented only if individuals and businesses stop using toxic substances that cause air pollution in the first place. This would require the cessation of all fossil fuel-burning processes, from industrial manufacturing to home use of air conditioners. This is an unlikely scenario at this time. However, as of June 2010, the Environmental Protection Agency (EPA) put forth a proposal for a Federal Transport Rule, which sets stringent regulations on industrial and power supply manufacturing and handling. The regulations are designed to further reduce harmful emissions into the Earth's atmosphere.

Don't Miss

  • All types
  • Articles
  • Slideshows
  • Videos
  • Most relevant
  • Most popular
  • Most recent

No articles available

No slideshows available

No videos available

By using the site, you consent to the use of cookies. For more information, please see our Cookie policy.