Pollution

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Pollution is the introduction of contaminants into the natural environment that cause adverse change.[1] Pollution can take the form ofchemical substances or energy, such as noise, heat or light. Pollutants, the components of pollution, can be either foreign substances/energies or naturally occurring contaminants. Pollution is often classed as point source or nonpoint source pollution. Pollution started from the prehistoric times when man created the first fires. Modern awareness
Pollution became a popular issue after World War II, due to radioactive fallout from atomic warfare and testin
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Forms of pollution

The Lachine Canal in MontrealCanada, is polluted.
The major forms of pollution are listed below along with the particular contaminant relevant to each of them:
  * Air pollution:- the release of chemicals and particulates into the atmosphere. Common gaseous pollutants include carbon monoxide,sulfur dioxide, chlorofluorocarbons (CFCs) and nitrogen oxides produced by industry and motor vehicles. Photochemical ozone and smogare created as nitrogen oxides and hydrocarbons react to sunlight. Particulate matter, or fine dust is characterized by their micrometresize PM10 to PM2.5.
  * Light pollution:- includes light trespass, over-illumination and astronomical interference.
  * Littering:- the criminal throwing of inappropriate man-made objects, unremoved, onto public and private properties.
  * Noise pollution:- which encompasses roadway noise, aircraft noise, industrial noise as well as high-intensity sonar.
  * Soil contamination occurs when chemicals are released by spill or underground leakage. Among the most significant soil contaminantsare hydrocarbons, heavy metals, MTBE,[9] herbicides, pesticides and chlorinated hydrocarbons.
  * Radioactive contamination, resulting from 20th century activities in atomic physics, such as nuclear power...