Clean Air

People are mostly unaware of the air that is surrounding us because it is usually invisible, odorless and tasteless when in its unpolluted state. One becomes aware of the air when the wind blows, when the temperature changes, or when visibility is reduced (Palomba, 1979). Polluted air, normally, reduces the intake of oxygen necessary for healthy physiological functioning of the body, and can have severe health impacts (Editor, 2007).

Since the time of the Industrial Revolution, it has been evident that the air we breathe has a direct impact on our health. In 1880, 2200 Londoners were killed by toxic smog of coal smoke; in December 1952, the "Great Smog" of London brought the capital to a standstill and caused an estimated 4000 acute deaths, and an additional 8600 excess deaths during the first 3 months of 1953 (Stone 2002). The air quality in the United States has improved since the passage of the Clean Air Act in 1970; however, it still poses a threat to human health. In 2005, the Environmental Protection Agency (EPA) estimated that over 122 million Americans live in areas with poor to marginal outdoor air quality.

In the United States, air quality is regulated by the EPA under the authority given by Congress in the Clean Air Act. The EPA establishes and monitors health-based standards for six criteria pollutants: carbon monoxide, lead, nitrogen oxide, ozone, particulate matter, and sulfur dioxide. These pollutants are chosen not only because they are highly prevalent, but also because they cause the most adverse effects on public health (NHDES, 2006).

The Clean Air Act provides the principal framework to protect air quality. Improvements in air quality are the result of effective implementation of clean air laws and regulations, as well as efficient industrial technologies. The EPA has a number of responsibilities due to the Clean Air Act, including: conducting periodic reviews for the six principal pollutants that are considered harmful to public health and the environment, ensuring that these air quality standards are met through national standards and strategies to control air pollutant emissions from vehicles, factories, and other sources, reducing emissions of SO2 and NOx that cause acid rain, reducing air pollutants such as PM, SOx, and NOx, which can reduce visibility across large regional areas, including many of the nation's most treasured parks and wilderness areas, ensuring that sources of toxic