What Are We Breathing?

Poor air quality is the culprit for the consequences that are being suffered by many human and plant communities. Air pollution, smog, or acid rain; it may be called whatever you like, it is the effects that it is causing that are important. Although many people associate smog with Los Angeles, it is not the only area that has been effected by poor air quality. Many national parks, aquatic systems, and other populated areas are showing major signs of air pollution.

"A large pollution study revealed that when smog increases in the Los Angeles Basin area, there is a big jump in the number of people hospitalized for lung and heart problems (Dreher 1998)." The effects of air pollution can be seen even below the levels that are indicated by air quality standards, since people respond differently to poor air quality. "Concentrations of harmful chemicals in the air have been proven to inflame and destroy lung tissue and weaken the lung defenses. Germs and dirt are normally trapped in the mucus in our air passages and removed by tiny hairs called cilia before entering our lungs. Polluting chemicals can paralyze the tiny cilia, allowing germs to build up in mucus or leave our body poorly protected against disease (Dreher 1998)."

"The U.S. Centers for Disease Control and Prevention (CDC) estimates that pollution is associated with between 50,000 and 120,000 deaths every year (Dreher 1998)." The people most affected by poor air quality are people with asthma, bronchitis, heart disease, and similar health conditions. Studies have also shown that children and the elderly may be affected more than adults. "Children are affected more severely than adults because theft airways are relatively narrower and more easily obstructed, and their oxygen demand relative to body weight is higher, resulting in relatively larger inhaled volumes (van Bree 1993)."

The major pollutants that comprise poor air quality, or smog, are: sulfur dioxide, nitrogen dioxide, carbon monoxide, volatile organic compounds (VOCs), ozone, suspended particulates, and greenhouse gases (carbon dioxide and methane). Studies have shown that ozone produces the most negative effects on humans. "These effects include coughing, difficulty in breathing, chest tightness, and nausea; reduced lung functions with possible lung inflammation, hyperactivity, and alterations in lung clearance; special problems for persons with respiratory diseases; and decreased ability to exercise strenuously. Laboratory animal studies suggest there may be biochemical, immunological, and morphological changes in respiratory tract tissues (van Bree 1993)." Air pollution can also have effects that are less serious, but, nevertheless harmful. "It can make your eyes water, irritate your nose, and cause headaches, coughing, sneezing, sore throat, dizziness and nausea (Dreher 1998)."

To alert people of pollutant levels, the Environmental Protection Agency (EPA) reports a Pollutant Standards Index (PSI) every day. The PSI considers the levels of carbon monoxide, ozone, nitrogen, sulfur dioxide, and particulate matter in the air and uses a scale (from 1-500) to show the combined levels of pollutants in the air on a given day. If the PSI level is less than 50, then the air is considered to be healthy. However, a PSI of 300 or more may be hazardous to your health. When the PSI is above 400, the EPA highly recommends that everyone in the general population should remain indoors. Also at PSI levels of above 400, "premature death of ill and elderly persons may result (Dreher 1998)." Even PSI levels of around 100 are considered to be unhealthful; the EPA suggests that "susceptible individuals, such as those with heart or lung disease, should minimize outdoor activity (Underwood 1998)." For the above reasons it is very important to be aware of the PSI levels in the areas in which you live. Smog does not only occur in Los Angeles!

Many people believe that air pollution is mostly caused by automobile emissions, this is not necessarily the case. Many of the gases that were mentioned above do come from automobiles, but they also come from incinerators, power plants, construction sights, etc. In fact, the pollutant that seems to cause the most harmful effects on humans is the coarse particulate matter. Surprisingly, scientists discovered that the hospitalizations of many people, as a result of air pollution, were more closely connected with increases in the amounts of coarse (large particles in the air that came mainly from grit blown from unpaved roads and construction areas) particles suspended in the air (Dreher 1998). Mostly, they amount to small, unnoticed changes in lung tissue that build up over time, possibly leading to earlier onset of lung disease and shorter lifespans (Brennan 1993). This shows that it is very important to take precautions as to avoiding long exposure to areas consisting of dusty dirt roads and construction sights.

Air pollution not only affects human health, it also affects the health of our environment. "Air pollution damages water ways, destroys trees, and clouds views in many of America's national parks (Tennesen 1997)." The National Park Service (NPS) has no authority over pollution that comes from outside park boundaries. Therefore, they can only try to make the surrounding areas aware of the problems emanating from the pollution.

Air pollution has begun to seriously affect our national parks. From the Great Smoky Mountains to the Grand Canyon, the pollution can easily, and often does travel hundreds of miles. So, even though the pollution is not necessarily occurring in the areas of the parks, it is still travelling there from miles away. "Though the problem is worse in the East--affecting plant life as well as visibility--air pollution is a factor in virtually every park in the United States (Tennesen 1997)."

Although the Great Smoky Mountains National Park is some 30 miles away from Knoxville, Tennessee, the air pollution created from the large population in the city has carried over and has had very grave effects on the national park. "The damage the mountains sustain comes primarily from acid rain and ozone created from sulfur and nitrogen emissions. Clouds over the Smokies can be a thousand times more acidic than natural rainfall--and more than 30 species of trees and plants in the park show injury from ozone, including black cherry, yellow poplar, blackberry, and milkweed (Tennesen 1997)."

At Grand Canyon National Park in Arizona, the affects of air pollution aren't necessarily shown through plant life because there isn't much of a plant life in the area. The area in Arizona is known for it's spectacular rock formations within the enormous canyon. Because of air pollution, those beautiful formations cannot always be seen.

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