Pollution

Pollution is the release of chemical, physical, biological or radioactive contaminants to the environment. Principal forms of pollution include:

• air pollution, the release of chemicals and particulates into the atmosphere. Common examples include carbon monoxide, sulfur dioxide, chlorofluorocarbons (CFCs), and nitrogen oxides produced by industry and motor vehicles. Ozone and smog are created as nitrogen oxides and hydrocarbons react to sunlight. water pollution via surface runoff and leaching to groundwater.
• radioactive contamination, added in the wake of 20th-century discoveries in atomic physics. (See alpha emitters and actinides in the environment.)
• noise pollution, which encompasses roadway noise, aircraft noise, industrial noise as well as high-intensity sonar.
• light pollution, includes light trespass, over-illumination and astronomical interference.
• visual pollution, which can refer to the presence of overhead power lines, motorway billboards, scarred landforms (as from strip mining), open storage of junk or municipal solid waste.

-- GeirThomasAndersen - 16 Sep 2006