Introduction
Air pollution is associated with concentrated populations, industrial growth, and high motor vehicle use characteristic of urban areas. These combined sources often exceed the capacity of the atmosphere surrounding urban areas to dilute pollutants. Major pollutants such as sulfur dioxide, carbon monoxide, nitrogen oxides, and particulate matter occur naturally in the atmosphere. However, the air is considered to be polluted when levels of these materials become harmful to life, cause damage to materials and structures, or impede visibility. Excessive or harmful levels of air pollution are generally caused by chemicals, smoke, or toxic substances that are by-products of human activities. Wind, natural chemical processes, and weather distribute and disperse these air pollutants.
Air pollution results from the addition of various substances and energy forms to the atmosphere. Other considerations include physical, chemical, biological, and psychological impacts that are determined by humans to be undesirable or detrimental. Air pollution can occur in indoor locations as well as in the outdoor (ambient) atmosphere.
All of the following aspects are impacted by air pollution: (1) human health (increases in death and Illness from cancer, heart, and lung diseases linked to air pollution); (2) plant and animal life (chronic injury inflicted on living organisms and ecosystems and on agriculture, forests, and ornamental vegetation by increasing quantities and varieties of air pollution); (3) materials and buildings (sulfur dioxide contributing to early aging and damaging of a variety of materials, ozone, and particulate matter, resulting in costly damage and soiling of paints and other materials); (4) climate, acid rain, and other global effects (air pollution altering the natural climate and atmosphere unpredictably with resulting negative effects on the global environment); and (5) visibility (air pollution dimming visibility, obscuring scenic and aesthetic views, and interfering with safe transportation). The negative effects of air pollution are compounded......
