Additonal Information

Air Pollution Reduction
Reducing air pollution through energy efficiency

In the United States, about two-thirds of the electricity we use is generated by power plants that fossil fuels to produce energy. 

When fossil fuels are burned in the production of electricity, a variety of gases and fine particles are emitted into the air, contributing to adverse health effects and air pollution.

Air pollution is a problem for humans, animals, ecosystems and the built environment.  The average adult breathes 3,000 gallons of air every day.  Children breathe twice as much per pound of body weight and are, therefore, more susceptible to the effects of air pollution, such as increased asthma rates and serious respiratory problems.

Air pollutants can remain airborne for long periods of time and can be carried by winds for hundreds of miles. 



The most prevalent air emissions from coal-burning power plants are the following:

  • Carbon dioxide, or CO2, is released to the atmosphere when fossil fuels such as oil, natural gas, and coal are burned, and is considered a primary greenhouse gas.

  • Nitrogen Oxides, or NOx, is the generic term for a group of highly reactive gases, all of which contain nitrogen and oxygen in varying amounts.  NO2 gives smog its yellowish-brown layer, which can cause visibility problems in many urban areas, most noticeably in national parks.

  • Sulfur dioxide, or SO2, belongs to the family of sulfur oxide gases (SOx). Over 65%  of SO2 released to the air, or more than 13 million tons per year, comes from electric utilities, especially those that burn coal.  SO2 reacts with other chemicals in the air to form tiny sulfate particles. 

  • Mercury, or Hg, is an element in the earth's crust. Pure mercury is a liquid metal, and has traditionally been used to make products like thermometers, switches, and some light bulbs.  Mercury is found in many rocks including coal. When coal is burned, mercury is released into the environment. Coal-burning power plants are the largest human-caused source of mercury emissions to the air in the United States, accounting for about 40 percent of all domestic mercury emissions. Burning hazardous wastes, breaking mercury products, and the improper treatment and disposal of products or wastes containing mercury, can also release it into the environment.  Mercury in the air eventually settles into water or onto land where it can be washed into water. Once deposited, microorganisms can change it into methylmercury, a highly toxic form that builds up in fish, shellfish and animals that eat fish.  Fish and shellfish are the main sources of methylmercury exposure to humans.

  • Particulate matter, or PM, is the term for particles found in the air, including dust, dirt, soot, smoke, and liquid droplets. PM-10 is filtered naturally by the hairs in your nose as you breathe, but PM-2.5 is much smaller and passes into the lungs.

  • Volatile Organic Compounds, or VOCs, combine with nitrogen oxides and sunlight to form ozone.  Ozone has the same chemical structure whether it occurs miles above the earth or at ground level and can be "good" or "bad," depending on its location in the atmosphere.  "Good" ozone occurs naturally in the stratosphere approximately 10 to 30 miles above the earth's surface and forms a layer that protects life on earth from the sun's harmful rays.  In the earth's lower atmosphere, ground-level ozone is considered "bad" because it can cause respiratory problems and damages plants and ecosystems.  Remember the phrase -- "Good up high; bad nearby"

  • Carbon Monoxide, or CO, is a colorless, odorless gas that is formed when carbon in fuel is not burned completely.   At extremely high levels, CO is poisonous and can cause death.


Reducing energy consumption by using energy-efficient products such as lowers the need for power plants to generate electricity, which means that they burn fewer fossil fuels and emit fewer harmful pollutants.