The Air People Breathe

According to the Environmental Protection Agency (EPA), the average person breathes in 3,400 gallons of air each day. Because air is so essential to life, it is important that it be free of pollutants. Throughout the world poor air quality contributes to hundreds of thousands of deaths and diseases each year, not to mention dying forests and lakes and the corrosion of stone buildings and monuments. Air quality is also important to the quality of life and recreation because air pollution causes haze that decreases visibility during outdoor activities.

Fossil fuels and chemicals have played a major role in society's pursuit of economic growth and higher standards of living. However, burning fossil fuels and releasing toxic chemicals into the air alter Earth's chemistry and can threaten the very air on which life depends.

What Are the Major Air Pollutants?

Air quality standards established...