Stationary and Mobile Causes
Although there are some natural types of air pollution, such as methane which is released as part of the mammalian digestive process, air pollution that can lead to diseases and are of most concern to society are the unnatural causes. These are the ones we have the power to control and change.
Unnatural causes of air pollution can be divided into two primary categories: stationary and mobile.
Stationary Causes for Air Pollution
As the name suggests, stationary causes are ones that do not move. These would include primarily power and energy plants where oil or coal is refined or burned. Although we do need power for a myriad of reasons in our daily lives, the results of using these polluting forms of the power generation process release many dangerous chemicals into the air.
One of the most common of these chemicals is sulfur dioxide. When coal and other fuel sources are burned, this chemical is released and can have damaging effects on the people in the surrounding areas. When present in low concentrations, the compound is not extremely dangerous. However, the concentrations around these plants can be very high and that can lead to serious breathing problems in the residents of surrounding areas. Of course, the wind also moves these concentrations of sulfur dioxide where they begin to mix with a host of other pollutants in the air; spreading the pollution and causing problems for areas far away from the plants.
Mobile Causes for Air Pollution
Every time we drive a car, boat, or truck, we are releasing large amounts of pollutants into the atmosphere. As the gasoline is burned by our engines to power the vehicle, waste products are being released into the air through the exhaust system. These waste products include high levels of poisonous carbon monoxide, nitrogen oxide, and hydrocarbons.
Nitrogen oxide in large amounts contributes to acid rain when it is combined with sulfur dioxide from those stationery sources. It is also one of the leading causes of high levels of ozone in the atmosphere which makes breathing difficult.
Another Air Pollution Cause
Other primary causes of air pollution are chlorofluorocarbons (CFCs). These are chemicals released into the atmosphere through the use of aerosol cans, air conditioners, refrigeration units, burning some types of foam, and similar sources. CFCs are believed to be the chief cause of the disintegration of the ozone layer in the atmosphere which reduces the amount of ultraviolet light reaching earth. That’s because as the CFCs move upward through the atmosphere and come in contact with light radiation they release atoms that convert ozone (O3) into oxygen (O2).
Besides the problems associated with the reduced ozone layer, CFCs are also believed to play an important role in photochemical smog which has become increasingly common in urban areas especially during the summer.