30-01-2013, 04:54 PM
POLLUTION & TYPES OF POLLUTION
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INTRODUCTION
Pollution is the introduction of contaminants into an environment, of
whatever predetermined or agreed upon proportions; these contaminants cause
instability, disorder, harm or discomfort to the physical systems or living
organisms therein.
Pollution can take the form of chemical substances, or energy, such as noise,
heat, or light energy. Pollutants, the elements of pollution, can be foreign
substances or energies, or naturally occurring; when naturally occurring, they are
considered contaminants when they exceed natural levels.
Major forms of pollution
The major forms of pollution are listed below along with the particular pollutants
relevant to each of them:
• Air pollution, the release of chemicals and particulates into the
atmosphere. Common air pollutants include carbon monoxide, sulfur
dioxide, chlorofluorocarbons (CFCs) and nitrogen oxides produced by
industry and motor vehicles. Photochemical ozone and smog are created as
nitrogen oxides and hydrocarbons react to sunlight.
• Water pollution, by the release of waste products and contaminants into
surface runoff into river drainage systems, leaching into groundwater,
liquid spills, wastewater discharges, eutrophication and littering.
• Soil contamination occurs when chemicals are released by spill or
underground leakage. Among the most significant soil contaminants are
hydrocarbons, heavy metals, herbicides, pesticides and chlorinated
hydrocarbons.
• Radioactive contamination, resulting from 20th century activities in atomic
physics, such as nuclear power generation and nuclear weapons research,
manufacture and deployment.
• 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 trash or municipal solid waste.
• Thermal pollution, is a temperature change in natural water bodies caused
by human influence, such as use of water as coolant in a power plant.