What is Air Pollution? Air pollution is actually the addition of any harmful substances to the atmosphere, which causes the damaging of the environment, human health and the quality of life. With the development in industry, came along the increase in air pollution, which occurs inside homes, schools, offices even in the countryside. Consequently there has been an increase in the death rates resulting from various diseases caused by air pollution varying from breathing problem to lung cancer. Air pollution does not only affect people but it also damages the whole ecological system in which plants and animals are harmed as well. Air pollution has reached such a critical stage where it affects the earth's atmosphere as it lets in more harmful radiation from the sun. Consequently, our polluted atmosphere is becoming a better insulator, thus, preventing heat from escaping back into space. That is why there is a global rise in temperature which scientists refer to as " global warming". As a result of this rise in temperature the world food supply and sea level will be affected, also there is the probability of increase in the tropical disease. Sources of Air Pollution I_ Human sources: If we try to investigate the major sources of pollution, we realize that they stem out of human activities. Burning fossil fuels, natural gases, coal and oil, factories and motor vehicles all emit harmful substances. Among these harmful chemical compounds this burning adds to the atmosphere are carbon dioxide, carbon monoxide, nitrogen oxides, sulfur dioxide, and solid particles called particulate. Between 1900 and 1970 the use of motor vehicles expanded which resulted 690% increase in the damaging pollutants in vehicle exhaust. Another source of pollutant is the decomposing of garbage in landfills and solid waste disposal which emit methane gas, and many households products give off what is known as volatile organic chemicals sources: 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.