Air Pollution

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It is important to point out that some pollutants originate from natural sources. For example, forest fires emit particulate and VOCs; ultra fine dust particles in the atmosphere. Finally, volcanoes give out sulfur dioxide and volcanic ash; a big volcanic eruption can darken the sky over a wide region and affect the earth's atmosphere. Unlike pollutants from human activity, however, naturally occurring pollutants remain in the atmosphere a short time and do not lead permanent atmospheric change.

Types of Air Pollution

I_ Local and Regional Pollution:
One type of air pollution is referred to as local and regional pollution, which take place in the lowest layer of the atmosphere, the troposphere. This layer is the one in which most weather occurs. /in the weather phenomenon known as thermal version, a layer of cooler air is trapped near the ground by a layer of warmer air above. When this happens pollutants are trapped in the lower layer, as an example of this is smog. Before the automobile, most smog came from the burning of coal; today the main source of smog is the burning of gasoline by motor vehicles. Smog contains ozone, which is a form of oxygen gas made up by molecules with three oxygen atoms rather than the normal two. Ozone in the lower atmosphere is poison since it destroys crops, kills trees and harms the lungs. When the ozone level is high, other pollutants, including carbon monoxide, are usually present at high levels. Smog can also damage anything else made of limestone, marble or metal, which causes the erosi!
on of precious monuments.

II_ Global Pollution:
Air pollution can expand beyond the aforementioned regional areas to cause global affects, thus, known as global pollution. The stratosphere is the layer of the atmosphere between 16_50 Km above sea level. This layer is rich in ozone, the same molecule that acts as a pollutant at the troposphere level. However, at the stratosphere level the ozo...