Main Types of pollution
- Air pollution
- Water pollution
- Land pollution
- Thermal pollution
- Noise pollution
- Radioactive pollution
- Light pollution
Write a note on pollution?
The undesirable changes in the physical, chemical or biological characteristics of air, land and water that harmfully affect human life and organisms are termed as “Pollution” or it is introduction of harmful wastes into the environment.
- Many of the waste end-products of modem technology are toxic.
- These toxic wastes when thrown in our environment threaten the lives of many organisms of that ecosystem.
TYPES OF POLLUTANTS AND THEIR SOURCES
- Those agents or substance which cause pollution are called Pollutants there are following types of pollutants
2) Thermal Pollutants
3) Chemical Pollutants
4) Air Pollutants
- Sewage consists of he faeces an i mtrogenous wastes of animals which is rich ¡n organic matter and nitrogen compounds.
- When used as a fertilizer in moderate concentrations this animal waste (manure) can enrich the soil hut if it is allowed to accumulate in lakes and rivers the water become greatly polluted and can seriously affect the ecosystem.
- THERMAL POLLUTANTS
- The discharge of hot water into river and estuaries from power stations ¡s a pollutant because it raises the temperature of the water, thereby increasing the metabolic rate and oxygen consumption of the microorganism this makes it more difficult for fish to survive.
- CHEMICAL POLLUTANTS
- industrial wastes and sewage, both arc the chemical pollutant.
- The chemical constituents of the sewage arc extracted by natural or artificial means and returned to the ecosystem.
- This however, is not always possible with chemical pollutants that arise from industrial Process.
- I) Mercury
- It is a byproduct of various processes and a Constituent of certain agricultural fungicides.
- There is evidence that the level of Mercury in fresh water lakes and river in recent >cars and it can become highly concentrated in the bodies of fishes.
- ii) Lead
- It is another serious chemical pollutant
- People contain varying amounts of lead in their bodies and it comes mainly from motor vehicle exhaust and old deteriorating paint.
Oil is a major pollutant particularly in the sea and kills sea birds and phytoplankton’s.
- AIR POLLUTANTS
- I) Smog
- Smog is a mixture of smoke and fog.
- Fog is the accumulated water vapours suspended near earth’s surface,
- Smoke arises from many sources including factories, steel works. oil refineries. chemical plants of course from the automobiles.
- Its ingredients include carbon monoxide, carbon dioxide, sulphur and nitrogen oxides, lead and various hydrocarbons.
- These pollutants arc trapped in the fog to form the smog.
- Its general effects include eye irritation, headache, silk and breathing difficulties.
- People with respiratory diseases, such as chronic, bronchitis and emphysema are more vulnerable to smog’s hazards.
Il) Acid Rain
- Sulphur dioxide and oxides of nitrogen arc the product of coal, oil and natural gas burning.
- They react readily with oxygen and rain water to form dilute sulphuric acid arid nitric acid respectively.
- Rain containing these acids is known as acid rain.
- Acid rain dissolves aluminum salts in the soil and washes them into
- These salt, may reach a concentration that is poisonous to fishes.
- It also damages the building and is sometimes called stone cancer.
Green house effect
- Carbon dioxide and other gases keep the earth warmer, carbon dioxide allows the sunlight pass freely through the atmosphere to reach the ground. The ground is warmed by radiation and emits infrared radiation. Carbon dioxide does not Iet all of this infrared radiation pass through this is called green house effect.
- The amount of carbon dioxide and other green house gases in the atmospheric is increasing as a result of human activities.
- This traps more infrared radiation and makes the atmosphere. This is called the enhanced green house effect, as a result the earth’s temperature is rising. This phenomenon is called “Global Warming”.
- Other gases which contribute to the green house effect are also being released in the atmosphere by human activities these includes methane, nitrous oxide and CR’s
(Chloro fluro carbons)
- It is thus important that we cut down the emission of green house gases. One obvious
way do this is to reduce the amount of fossil fuels which are being burnt this
Id reduce the amount of carbon dioxide we pour into the air.
Depletion of Ozone Layer
- Ozone layer lies high up around the earth in its atmosphere between 12 Lo 15 Km above the ground. ‘“
- The Ozone layer protects the earth and its organisms from harmful effects of ultra violet rays of the sun.
- The Ozone (03) with 3 oxygen atoms is constantly being formed, broken down and reformed.
- It is formed when ultraviolet light from sun hits an oxygen molecule. The two oxygen atom breaks apart. forming separate and very reactive individual oxygen atoms.
- Each of these can then combine with an oxygen molecule to form an ozone
molecule. O + 0 O3
- This reaction takes place high up in the atmosphere because that is where the most ultraviolet light is present.
- Most of these health threatening ultraviolet rays arc absorbed by the ozone layers and much less is allowed to pass into the lower layers of the atmosphere to reach the earth.
- Ozone layer is being broken down continuously by the action to chlorine in chlorofluorocarbons (CISs) discharged from foam industry, air conditions and refrigerators.
- It is required to develop better alternative of CFSs, to bring the Ozone layer hack to normal and to shield ourselves from the hazards of ultra violet rays.
- v) Soil Erosion
- Plants of the forest arc important in soil stability.
- The leafy canopy of the trees protects the soil from the impact of falling rain.
- When the trees removed, the soil is exposed directly to the force of rain and water run off becomes intension.
- Top soil, the most fertile layer, gets washed aw during heavy rain especially on
- steep slopes, leaving the soil unfertile.
- This washed off soil is deposited in the dams and other water reservoirs to bring their
water storing capacity rapidly down.