National Emissions Standards Act - Reducing Acid Rain

Reducing Acid Rain

Acid precipitation comes in more forms than just rain. Snow, fog, mist, gas, and dust are also formed in the atmosphere and have the ability to become acid precipitation. These types of precipitation are formed when certain types of air pollutants mix with the moisture in the air to form an acid. Each type is potentially dangerous to humans' health, can cause haze and problems in the environment, and can cause damage to people's properties. The two main pollutants that cause acid precipitation are sulfur dioxide (SO2) and nitrogen oxides (NOx). Power plants that burn coal and "heavy oil" are accountable for over two-thirds of SO2 emissions annually in the U.S., while automobiles emit about fifty percent NOx and power plants emit about forty percent. The remaining percentages are from industrial and commercial boilers.

Any toxin is harmful to life on Earth. Acid rain and snow can increase the acidity in lakes and streams long enough to harm fish and other forms of life. Sulfur dioxide can be dangerous to children and the elderly by causing serious damage to lung tissue. In 1990, the Clean Air Act was changed to include a "nationwide approach" to lowering SO2 and NOx emissions. A cap was placed on the total SO2 emissions from electric power plants across the U.S.