Pollution 

                              Pollution is the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of chemical 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.

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 smog are created as nitrogen oxides and hydrocarbons react to sunlight. Particulate matter, or fine dust is characterized by their micrometre size PM₁₀ to PM_2.5.

• 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 contaminants arehydrocarbons, heavy metals, MTBE,^[9] 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. (See alpha emitters and actinides in the environment.)
• 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.
• Visual pollution, which can refer to the presence of overhead power lines, motorway billboards, scarred landforms (as from strip mining), open storage of trash, municipal solid waste or space debris.
• Water pollution, by the discharge of wastewater from commercial and industrial waste (intentionally or through spills) into surface waters; discharges of untreated domestic sewage, and chemical contaminants, such as chlorine, from treated sewage; release of waste and contaminants into surface runoffflowing to surface waters (including urban runoff and agricultural runoff, which may contain chemical fertilizers and pesticides); waste disposal and leaching into groundwater; eutrophication and littering. (from the wikipedia)

LOOK THE VIDEO AND SAY WHAT ARE THE CAUSES OF POLLUTION? DISCUSS THE VIDEO: