Air is the life line for all beings on this planet, and air pollution our nemesis. Air supplies us with the vital oxygen which is essential for nearly all life forms on this planet to live. Air is 99.9% nitrogen, oxygen, water vapor and inert gases. Detrimental human activities can release harmful substances into the air, some of which can cause problems for humans, plants, and animals.
There are several different types of this pollution and well-known effects of pollution which are commonly discussed. These include smog, acid rain, the greenhouse effect, and the holes in the ozone layer. Each of these problems has serious implications for our health and well-being as well as for the whole environment.
One type of pollution in the air is the release of tiny particles into the air from burning fuel for energy. Diesel smoke is a good example of this particulate matter . The particles are very small pieces of matter measuring about 2.5 microns or about .0001 inches. This type of pollution is sometimes referred to as black carbon pollution. The exhaust from burning fuels in automobiles, homes, and industries is a major source of this type of pollution in the air. Some authorities believe that even the burning of wood and charcoal in fireplaces and barbeques can release significant quantities of soot into the air. Another type of pollution is the release of noxious gases, such as sulfur dioxide, carbon monoxide, nitrogen oxides, and chemical vapors which can ultimately take part in further chemical reactions once they are in the atmosphere, forming smog and acid rain.
This pollution is a problem inside our homes, offices, and schools that needs to be considered as well. Some of these indoor air pollutants can be created by such indoor activities like smoking and cooking. In the United States, we spend approximately 80-90% of our time inside buildings, and so our exposure to harmful indoor air pollutants can be a serious problem which we must consider. It is therefore important to consider both outdoor and indoor air pollution when discussing this topic.
Smog is a type of large-scale outdoor pollution and can cover vast areas. It is caused by chemical reactions between pollutants derived from different sources, primarily from the exhaust of automobiles and industrial emissions. Cities are most often the epicenters of these types of events, and many can suffer from the effects of smog, especially those with asthma or other breathing ailments, and, most particularly, during the warm summer months. Additional information about smog and its effects are available from Environment Canada and the Air Quality Management District (AQMD) in southern California.
For each city, the exact causes of pollution may vary, and depending on the geographical location of the city, the temperature, wind and other weather factors, pollution is dispersed somewhat differently. However, there are times when this does not happen and the pollution can build up to dangerous levels inside a sort of bubble. A temperature inversion occurs when air close to the earth is cooler than the air above it. Under these conditions the pollution cannot rise and be dispersed normally. Cities surrounded by mountains also experience trapping of pollution, such as the Los Angeles area, which is infamous for it’s effects. Inversion can happen in any season of the year. Winter inversions are more likely to cause particulate and carbon monoxide pollution, while inversions in the summer are more likely to create smog.
Another consequence of the industrial revolution and outdoor air pollution is acid rain. When a pollutant, such as sulfuric acid combines with droplets of water in the air, the water, or snow may become acidified . The effects of acid rain on the environment can be very disastrous. It damages plants by destroying their leaves, it poisons the soil, and it changes the chemistry of lakes and streams. Damage due to acid rain kills trees and harms animals, fish, and other wildlife. The U.S. Geological Survey (USGS), the Environmental Protection Agency (EPA), and Environment Canada are among the organizations that are actively studying the acid rain problem and looking for solutions.
The Greenhouse Effect, which can also be classified as outdoor air pollution, and also referred to as global warming, is generally believed to come from the build up of carbon dioxide gas in the atmosphere. Carbon dioxide is produced when fuels are burned in internal combustion engines. Plants convert carbon dioxide back to oxygen, but the release of carbon dioxide from human activities is much higher than what the world’s plants can handle. This situation is being amplified and made worse since many of the earth’s forests are being removed, and plant life is being damaged by the acid rain. This brings us to the point that the amount of carbon dioxide in the air is continuing to increase, and we continue to increase our output, while further reducing forest and plant life. It is becoming a viscious circle that we must put an end to, and soon. As this buildup grows, it acts like a blanket and traps heat close to the surface of our earth. Changes of even a few degrees will affect us all through changes in the climate and even the possibility that the polar ice caps may melt. (One of the consequences of polar ice cap melting would be a rise in global sea level, resulting in widespread coastal flooding.) Additional resources and information about the Greenhouse Effect and global warming are available from the Environmental Defense Fund (EDF), the Science Education Academy of the Bay Area (SEABA) and the Society of Environmental Journalists (SEJ).
Ozone depletion is another result of man made outdoor air pollution. Chemicals released by our activities affect the stratosphere , one of the atmospheric layers surrounding earth. The ozone layer in the stratosphere protects the earth from harmful ultraviolet radiation from the sun which is bad for us. The release of chlorofluorocarbons (CFC’s) from aerosol cans, cooling systems and refrigerator equipment removes some of the ozone, causing these holes to open up in this layer and thus allowing the radiation to reach the earth. Ultraviolet radiation is known to cause skin cancer and also has damaging effects on plants and wildlife. Additional resources and information about the ozone depletion problem are available from the National Oceanic and Atmospheric Administration (NOAA) and Ozone ACTION.
Many people spend large portion of time indoors – as much as 80-90% of their lives. We work, study, eat, drink and sleep in enclosed environments where air circulation may be restricted. For these reasons, some experts feel that more people suffer from the effects of indoor air pollution than from it’s counterpart, outdoor air pollution. There are many sources of indoor air pollution. Tobacco smoke, cooking and heating appliances, and vapors from building materials, paints, furniture, etc. cause pollution inside buildings. Radon is a natural radioactive gas released from the earth, and it can be found concentrated in basements in some regions of the United States. Additional information about the radon problem is available from the USGS and the Minnesota Radon Project. Pollution exposure at home and work is often greater than outdoors as we spend the majority of our time indoors. In addition, The California Air Resources Board estimates that indoor air pollution levels are 25-62% greater than outside levels and can pose even more serious health problems, which makes sense, seeing that indoors areas are confined, close quarters and most don’t have adequate ventilation, especially during the colder months. Both outdoor and indoor air pollution needs to be controlled and prevented, wherever possible.