Emily's Global Climate Change Scrapbook

Industrial Smog vs. Photochemical Smog

Industrial Smog (Gray air smog)

Industrial air smog is formed coal is burned, but is not completely combusted. This will leads to emissions of carbon dioxide, carbon monoxide, soot, mercury, and sulfur dioxide, which make up industrial smog.

While burning coal forms smog, weather and location can amplify its effects. Temperature inversion and mountain ranges can trap smog, making it much more lasting and dangerous.

While today in developed nations industrial smog is becoming less and less common, in undeveloped nations it still poses a large threat to both health and the environment.

Perhaps the most well-known example of industrial smog occurred in 1952 in London (above), England due to an increase in coal consumption. It lasted from December until March and resulted in over 4,000 deaths.

Another example of the deadly potential of industrial smog took place in Donora, Pennsylvania 1948 (above). Nearby hills contributed to thermal inversion, which trapped smog created by a steel and wire factory and lead to the death of 21 people.

Photochemical Smog (Brown air smog)

Photochemical smog is created by light-activated chemical reactions of more than 100 chemicals, including ozone and several primary pollutants. Many of the chemicals necessary for this type of smog are emitted by vehicles and industries burning fossil fuels.

Weather can also play a role in the formation of photochemical smog. Days which are hot, sunny, and windless are more likely to be impacted by photochemical smog.

The United States has managed to reduce the amount of smog by reducing emissions of its components by 30%. This was done by requiring period checks car exhaust. Photochemical smog is still much more common today in developed nations than industrial smog.

New Mexico (above) and Los Angeles (Below) are both notorious for their photochemical smog.

The Asian Brown Cloud (below) is another well-known example of photochemical smog.