Environmental Issues | IBPS PO Prelims & Mains Preparation - Bank Exams PDF Download

Introduction : Pollution and Pollutants - Environmental Issues, Biology, Class 12

ENVIRONMENTAL POLLUTION, ISSUES AND NATURAL RESOURCES

POLLUTION
"Any undesirable change in physical, chemical or biological characteristic of air, water and land which is harmful to the man directly or indirectly through the animals, plants industrial unit or raw materials is called pollution."

Pollutants : "Any material or product of man or nature which leads to pollution is called pollutants".

Type of Pollutant Usually Pollutants are Divided into Following Categories

1. Nondegradable pollutants : Many of such pollutants are usually not degraded or degraded partially in environment. Such as aluminium pecks, Mercury compounds of phenols, Glass, D.D.T., Benzene, BHC pesticides, etc.
They are collected in the environment and cause polluton. These pollutants are harmful even in low concentration and harm increases with their increasing concentration. No treatment is found in the nature for their recycling. There are only two methods by which we can stop the pollution caused by pollutant.
(i) Such type of substance should be banned by law.
(ii) Use their alternative substance.

Synergism - Formation of secondary pollutants is known as synergism. Secondary pollutants are more toxic than primary pollutants.

1. Quantitative pollutants - These are the susbtance which occur in nature but become pollutant when their concentration reaches beyond a threshold value in the environment.
eg., CO₂, Nitrogen oxide.

2. Qualitative pollutants - These are the substance which do not occur in the environment but are passed in through human activity.
eg., Fungicides, Harbicides, DDT etc.

Other type of pollution :
1. Natural pollution - Caused by natural sources like, CH₄ from paddy fields and cattle, marsh, forest fire.

2. Anthropogenic pollution - Caused by human activities.

Main sources of pollution :

(i) Point source pollution - Where the effluent discharge occur at a specific site.
eg., factory outlet and Municipal sewage

(ii) Line source pollution - It is passed along a narrow belt, Roads,
eg., Rods, Railway tracks.

(iii) Diffuse source pollution - It is over a large area.

eg., sprayed fertilizer or pesticides through run off.

(iv) Area source pollution - Industrial estate and mining area.

======================================================

Air pollution causes & effect - Environmental Issues, Biology, Class 12

AIR POLLUTION
The air pollution is caused due to addition of unwanted substances or gases. The atmospheric pollution is mainly caused by the activities of man and concentrated to the inhabited and the industrial complexes in cities.
There are two main categories of air pollutants :
(i) Gases 

(ii) Particulates
 (i) Gases
The gaseous materials include various gases and vapours of volatile substances or the compound with a boiling point below 200ºC.

Particulate matter :
Particulate matter consist of solid particles or liquid droplets (aerosols) small enough to remain suspended in air. eg., soot, smoke, dust, asbestos, fibres, pesticides, some metals (including Hg, Pb, Cu and Fe) and also biological agent like tiny dust mites and flower pollen.
Atmospheric particles having diameter > 10 μm, generally settle out in less than a day, whereas particles with diameters 1 μm or less can remain suspended in air for weeks.
Suspended particulate matter in the lower atmosphere (troposphere) causes and aggravates human respiratory illness, like asthama, chronic bronchitis etc.
According to Central Pollution Control Board (CPCB) particulate size 2.5 micrometers or less diameter (PM 2.5) are responsible for causing harm to human health as inhaled deep into lungs can cause breathing and respiratory symptoms, irritation, inflammations, damage to lungs & premature death.

MAJOR AIR POLLUTANTS AND THEIR EFFECTS
1. Carbon monoxide (CO) -
Source - It is the main air pollutant released from smoke of automobiles.
Effect - Carbon monoxide is highly toxic gas, it combines with haemoglobin of the blood and blocks the transportation of oxygen. Thus, it impairs repsiration and it causes death due to asphyxia when inhaled in large amount.

2. Unburn Hydrocarbons - (3,4 Benzopyrine, CH4, Benzene)
Source - These are mainly released from automobiles and burning of fossil fuel (coal, petrol, diesel). Methane (CH₄) is the most abundent hydrocarbon in atmosphere and its main source is marshy area and paddy field.
Effect - Hydrocarbons cause lungs cancer.
Polynuclear hydrocarbon is major hydrocarbon pollutant which cause cancer.

3. Ethylene -
Source - It main sources are automobiles, chimneys.
Effect - Falling of leaves without particular reason, falling of flowering bud before time.

4. Nitrogen oxide (NO, NO₂) -
Source - Burning (combustion) of fossil fuel in automobiles.
Effect - These nitrogen oxide form photochemical smog in atmosphere and release ozone.
Nitrogen oxide also responsible for acid rain. Entry of these nitrogen oxide causes respiratory trouble such as emphysema, bronchitis, swelling of lungs and lungs cancer etc.

5. Sulphur oxide (SO₂, SO₃)
Source - These are most harmful gaseous pollutants, main source of sulphur oxides are coal burning,  smelters, oil refineries.
Effect - Lichen and mosses do not grow in SO₂ polluted areas, Lichen and mosses are
indicator of SO₂ pollution. Oxides of sulphur produce acid rain and smog in atmosphere.

6. Smoke - (SO₂, SO₃, NO₂, NO, CO, CO₂)

SECONDARY POLLUTANTS
A. Smog (Smoke + Fog) -
This word was given by Desvoeux. Smog/Smoke is measured by Ringlmann method.
(a) Los Angles Smog or Photochemical smog -
It was first observed in Los Angeles. In this process smoke, fog, nitrogenoxide, hydrocarbons, oxygen, UV light and high temperature are essential. These components react with each other and form reddish brown smog (PAN + O₃ + Nitrogen oxides) or brown haze/brown air.
Los angeles smog is light induced smog.
Effect -
Due to smog elastic susbtances (rubber/tyres) also affected. Smog causes damage in rubbers.
During smog peroxyacetyl nitrate (PAN) is formed. PAN stops or inhibits the photolysis of water in hill reaction of photosynthesis and inhibit the photosystem-II. PAN also inhibit the chlorophyll formation in plants.
In animals PAN cause irritation in eyes and harms the lungs.
Ozone causes harm to mucous membrane.

(b) London smog or sulphur smog -
It was first observed in London. In this process coal, smoke, fog, sulphure oxide and low temperature are involved. These components react with each other and form vapour (Fog) of H₂SO₄ which is known as London smog.
Effect -
Due to inhalation of H₂SO₄ vapour with fog 4000 people died in London in 1952.

B. Acid rain-
This word was given by Robert August. NO₂ and SO₂ released from different sources in form of smoke and dissolved in atmospheric water vapour to form sulphuric acid and nitric acid (H₂SO₄ + HNO₃).
These acids come down on earth with rain water, this is called acid rain.
Wet deposition :- If acid comes down on earth with rain, fog and smog, it is known as wet deposition.
Dry deposition :- If acid settled on earth surface through solid dust particles with nitrate or sulphate, this is called dry deposition.

Note :
The pH of acid rain is 3.5-4 while for normal rain is 5.6
In acid rain the ratio of H₂SO₄ and HNO₃ is 7 : 3 (70% H₂SO₄ + 30% HNO₃)

Effect -
Due to acid rain acidity of soil and water increases.
Acid rain also cause damage historical monuments. eg., Taj Mahal, Red fort.

GREEN HOUSE EFFECT
Without green house effect the average (mean) temperature of earth surface were –18º C rather than
present 15 ºC.
Usually carbon dioxide is not considered as pollutant, but its higher concentration forms a thick layer
above the earth's surface, checks the radiation of the heat from the earth surface. Because of this,
temperature of the earth's surface increases, this is called "Greeen House Effect" or Global warming.

The relative contribution of various Green House Gases to total Global Warming
Main green house gases are CO₂, CH₄, CFC, N₂O. These are radiation active gases, Because they
absorb long wave infra red radiations. SO₂, NO₂, O₃ not contribute in green house effect. Water vapour
are also released from industries and agriculture which are responsible to increase the green house effect.

In this phenomenon cover of CO₂ layer around the earth, allow the short wavelength (U.V. rays) incoming solar radiation to come in but does not allow the long wavelength (IR) of out going heat radiation from warm surface of earth and surface keep to earth warm. The consequent increase in the global mean temperature is reffered to as a global warming.

Effects of Green House Gases :

1. It has been observed that in the recent past, the level of CO2 in the atmosphere has increased from 280 ppm to 368 ppm in 1956 to 2002. If present growth rate is continued then the amount of CO2 will be doubled upto 2020 century. Even 2-3ºC rise in temperature will be lead to melting of glaciers and ice caps of polar region and consequently the floods in rivers, rise in sea level and changes in cycle of rain. Islands may be submerged in sea water. CO₂ conc. in 2009-2010 is 385ppm.

2. Carbondioxide fertilisation effect - Due to increased CO2 concentration the rate of photosynthesis
will increase (up to a few year). The response of the plants to elevated concentration of CO2 is known as the CO2 fertilization effect, if would be shown by C₃ plant, if rest of environment factors are optimum. The stomatal conductance decrease (due to partial closure of stomata). Thus transpiration may be reduced and water use effeciency will increase. It allows many species to grow successfully in regions of water scarcity.
* Under high CO₂ conc. higher rate of photosynthesis provide high amount of food to roots. This greater root production enhence mycorrhizal development and N₂ fixation in root nodules and enables the plant to grow in nutrient poor soil.
* But all these effects are possible only when the rest of environmental factors are optimum.

3. The global mean temperature has increased by 0.6ºC in 20th century. Depletion of ozone layer
in stratosphere.

4. Sea level has been raised by 1 to 2 mm per year during 20th century.

Control of Global Warming :
UNCED (United Nations Conference on Enivronment and Development) Earth Summit held at Rio-de-
 Jenerio (Brazil) in 1992 for reducing green house gases and biodiversity conservation and
 make Agenda-21.
Kyoto protocol conference held in Kyoto (Japan) for climate change (1997). This protocol requires countries to take appropriate measures to reduce their overall green house gas emisson to a level at 5 percent below the 1990 level by the commitment period 2008-2012.

Earth Summit or world summit on sustainable development (2002) was held in Johanncsburg
(S.Africa).
1. Reducing the green house gases emission by limiting uses of fossil fuel and developing alternative
renewable sources of enenrgy (wind and solar energy).
2. Increasing the vegetative cover mainly forests for photosynthetic utilization of CO₂.
3. Minimizing the use of Nitrogen fertilizers in agriculture for reducing N₂O emission.
4. Developing substitute for CFC's.

CONTROL OF AIR POLLUTION
1. Control of particulate matter - Two devices are use to remove particulate air pollutants.
(a) Arresters

(b) Scrubbers

(a) ARRESTERS :
These are used to separate particulate matters from contaminated air.

Arresters are of different types :
(i) Cyclonic separators and Trajectory separators : These are commonly used to separate out particulate matters from industrial emissions with minimum moisture content. These separators work on the principle of dust separation by centrifugal force.
(ii) Electrostatic Precipitator : It is the most efficient device to remove fine particulate pollutants.
Electrostatic precipitation device work on the principle of electrical charging of the dust particles and collecting it on a differently charged platform.
* It can remove 99% of particulate matter present in exhaust form a Thermal Power Plant. It has electrode wire (act as anode) which maintained at several thausend volts, which produce carona and release electrons.
These electrons attached to dust particles providing them negative charge. The base have collecting plate (acts as cathod) and attracts the charged dust particles.
The low velocity air is provided between the plates which allow the dust to fall.

(b) SCRUBBERS:
These are used to clean air for both dust and gases. Wet and dry two types of scrubbers are used for dust separation.
They can remove gases like sulpher. In scrubber the exhaust is passed through a sprey of water or lime.

2. Control of gaseous pollutants : Combustion, absorption and adsorption technique are used to control gaseous pollutants.
(a) Combustion - In combustion process, oxidisable gaseous pollutants are completely burnt at a high temperature. Petrochemical, fetilizer, paints and varnish industries used combustion control of gaseous pollutants.
(b) Absorption - In this technique, gaseous pollutants are absorbed in suitable absorbent materials.
(c) Adsorption - This technique is applied to control toxic gases, vapours and inflammable compounds
that could not be efficiently removed or transferred by a fore said technique. Such air pollutants
are adsorbed on large solid surface.
(d) Catalytic converters : Automobiles are a mojor cause for atmospheric pollution in the metro cities. Proper maintenance of automobiles along with use of lead free petrol or diesel can reduce the pollutants they emit. Catalytic converters having expensive metals platinum, palladium and rhodium as the catalysts, are fitted into automobiles for reducing emission of poisonous gases.
As the exhaust passes they catalytic converter, unburnt hydrocarbons are converted into CO₂ and water, CO and nitric oxide are changed into CO₂ and nitrogen gas repectively. Motor vehicles equipped with catalytic converter should use unleaded petrol because lead in the petrol inactivates the catalyst.

Some other Method -
1. Engines should not be kept started when vehicle is in rest condition.
2. Barium compound mixed with petrol reduce the smoke.
3. It is also very essential to check the quality of gases released from the factories.
4. Industries should not be established at one place.
5. The smoke should be released into the atmosphere after filtration and purification (by cyclone collector or electrostatic precipitators)
6. To seperate particles larger than 50 μm, gravity settling tanks or porous filters are being used.

Controlling Vechicular Air Pollution : (A case study of Delhi)

1. With its very large population of vehicular traffic, Delhi leads the country in its level of air-pollutionit has more cars than the state of Gujrat and West Bengal put together.

2. In the 1990s, Delhi ranked fourth among the 41 most polluted cities of the world. Air pollution problems in Delhi becomes so serious that a Public Interest Litigation (PIL) was filed in the Supreme Court of India. After being censured very strongly by the Supereme Court, under its directives, the government was asked to take, within a specified time period, appropriate measures, including switching over the entire fleet of public transport, i.e., buses, from diesel to compressed natural gas (CNG). All the buses of Delhi were converted to run on CNG by the end of 2002.

3. Why CNG is better than diesel. The answer is that CNG burns most efficiently, unlike petrol and diesel, in the automobiles and very little of it is left unburnt. Moreover CNG is cheaper than petrol or diesel, cannot be siphoned off by thieves and adulterated like petrol or diesel.

4. The main problem with sweitching over to CNG is the difficulty of laying down pipelines to deliver
CNG through distribution point / pumps and ensuring uninterrupted supply.

5. Simultaneously parallel steps taken in Delhi for reducing vehicular pollution include phasing out of old vehicles, use of unleaded petrol, use of low-sulphur petrol and diesel, use of catalytic converters in vehicles, application of stringent pollution-level norms for vehicles, etc.

6. The Government of India through a new auto fuel policy has laid out a roadmap to cut down vehicular pollution in Indian cities. More stringent norms for fuels means steadily reducing the sulphur and aromatic content in petrol and diesel fuels. Euro-II norm, for example stipulate that sulphur be controlled at 350 parts-per million (ppm) in diesel and 150 ppm in petrol.

7. Aromatic hydrocarbon are to be contained at 42% of the concerned fuel. The goal, accroding to the roadmap, is to reduce sulphur to 50 ppm in petrol and diesel and bring down the level of 35%. Corresponding to the fuel, vehicle engines will also need to be upgraded.

8. The Bharat Stage-II (equivalent to Euro-II norms), which currently in place in Delhi, Mumbai, Kolkata, Chennai, Banglore, Hyderaba, Ahmedabad, Pune, Surat, Kanpur and Agra, will be applicable to all automobiles throughout the country from 1 April 2005.

9. All automobiles and fuel-petrol and diesel- were to have met the Euro-III emission specification in these 11 cities from 1 April 2005 and have to meet the Euro-IV norms by 1 April 2010. The rest of the country will have Euro-III emission norm compliant automobiles and fuels by 2010.

OZONE DEPLETION

1. Ozone is present in less quantity in atmosphere. But at height of 16 km to 25 km on earth, concentration of ozone is maximum in stratosphere.

2. Naturally there is bad ozone and good ozone. 'Bad' ozone, formed in the lower atmosphere (troposphere) that harms plants and animals. There is 'Good' ozone also; this ozone is found in the upper part of the atmosphere called the stratosphere, and it acts as a shield absorbing ultraviolet radiation from the sun.

3. UV rays are highly injurious to living organisms since DNA and proteins of living organisms preferentially absorb UV rays, and its high energy, breaks the chemical bonds within these molecules. The thickness of the ozone in a column of air from the ground to the top of the atmosphere is measured in terms of Dobson unit (DU).

4. Ozone gas is continuously formed by the action of UV rays on molecular oxygen in the stratosphere.
There should be a balance between production and degradation of ozone in the stratosphere. Of late, the balance has been disrupted due to enhancement of ozone degradation by chlorofluorocarbons (CFC's), CH₄, N₂O.

5. CFCs find wide use as refrigerants. CFCs. discharged in the lower part of atmosphere move upward
and reach stratosphere. In stratosphere, UV rays act on them releasing Cl atoms. Cl degrades ozone
releasing molecular oxygen, with these atoms acting merely as catalysts; Cl atoms are not consumed
in the reaction.

In this process one chlorine atom convert one each O₃ molecules into O₂ by photodissociation.
The life time of CF₂Cl₂ (CFC-12) is 139 year while that for CFCl₃ (CFC = 11) is about 77 years.

Hence, whatever CFCs are added to the stratosphere, they have permanent and continuing affects on Ozone levels. Although ozone depletion is occuring widely in the stratosphere, the depletion is particularly marked over the Antarctic region. This has resulted in formation of a large area of thinned ozone layer, commonly called as the ozone hole.

For making these discoveries related to ozone depletion or O3 destructruction. Sherwood Rowland,
 Mario Molina, Paul Curizen honoured with Nobel Prize for chemistry in 1995.

U.V. radiation of wavelengths shorter than UV-B, are almost completely absorbed by Earth's atmosphere,
given that the ozone layer is intact. But, UV-B damages DNA and mutation may occur. It causes aging of skin, damage to skin cells and various types of skin cancers (Melanoma). In human eye, cornea absorbs UV-B radiation, and a high dose of UV-B causes inflammation of cornea, called snow blindness, cataract, etc. Such exposure may permanently damage the cornea.

Recognising the deleterious affects of ozone depletion, and international treaty, known as the Montreal
 Protocol, was signed at Montreal (Canada) in 1987 (effective in 1989) to control the emission of ozone depleting substances.

Subsequently many more efforts have been made and protocols have laid down definite roadmaps,
separately for developed and developing countries, for reducing the emission of CFC's and other ozone
depleting chemicals.

At normal temperature and pressure thickness of ozone layere is 3 mm. (But at poles thickness of ozone layer is 4 mm).

Ozone hole was first discovered in 1985 over Antarctica by Nimbus-7 satalite. It is also confirmed
at Arctic in 1990.

The aerosols like C.F.C (Chloro flouro carbon) release into the atmosphere from the refrigerators, air conditioners and jet planes deplete or reduce the ozone layer. This is called ozone depletion and these substance are called O.D.S. (ozone depleting substance). This thin layer ozone is also known as ozone holes. (The decline in ozone thickness in spring time (Feb-April) is called ozone hole.)

Number of pollutants like CFCs (14% of total depletion), Nitrogen oxide [3.5%], CH₄ and halogens (chlorine) cause depletion of ozone layer. Maximum ODP (ozone depleting potential) is of CFCs due to release of chlorine.

2. Ozone hole occurs mainly during (July - October) and lowest during spring time (Feb. - Apr).
Means concentration of O3 is highest in stratosphere in Feb.-April (spring season) and lowest during July-October (Full season).

======================================================

Noise Pollution - Environmental Issues, Biology, Class 12
SOUND POLLUTION / NOISE POLLUTION
Air (Preventation and Control of pollution) Act. 1981 amended in 1987 to include noise as Air pollution.

Noise is undesired high level of sound.

Increase in the noise in the atmosphere is called noise pollution or sound pollution. Noise is a loud and unwanted or unpleasant sound. The common things which are responsible for noise pollution are industries
and mills, means of transportation, television, stereo, loud speakers and jet plane etc.

Intensity : The intensity of sound is measured in bel or decibel [1 bel = 10 decibel]. A man can hear at 0-decibel. Normally at 25 decibel, the atmosphere may be peaceful. Above 80 decibel intensity of sound is called noise pollution.

Effect : It causes drousyness, irritation, weakness and 130-140 decibel causes heart palpilation and pain. Noice pollution reduces the capacity of hearing and result in headache. Sudden excitation in skin, constriction of gastric muscles starts above the 90 decibel. It also produces excitation in habit of man and anger. Noise pollution causes ulcers, heart disease, high blood pressure, higher secretion of adrenal hormones etc. Excluding these, high intensity of sound can also break down the walls of the houses.

Control : Noise pollution can be control by the use of such type of apparatus which can decrease the
intesity of sound at place or origin. Sound absorbents must be used to minimise the sound. Growing
of more plants can also minimise the noise pollution, by Muffling.
Strict following of laws like delinitation of horn free zones around Hospitals, Schools, permissible sound
level of crackers and loud speakers, timing after which loud speakers not played etc.

=======================================================

Water Pollution, Eutrophication and Biomagnification - Environmental Issues, Biology, Class 12

WATER POLLUTION
The water pollution is caused by the addition of organic and inorganic chemicals as well as the biological materials which change the physical and chemical properties of water. This harmful process is called water pollution.
The water pollution is caused by many sources such as sewage matter, industrial wastage, agriculture wastage, domestic wastage, hot water of thermal plant and nuclear reactors etc.
Water having D.O. (Dessolved Oxygen) content below 8.0 mgL^–1 may be cosidered as contaminated and below 4.0 mgL^–1 heavily polluted.
D.O. is measured by oximeter.

1. Biochemical Oxygen Demand (B.O.D.) :
The water pollution by organic wastes is measured in term of Biochemical oxygen demand. It is the amount of dissolved oxygen (D.O. = Dissolved Oxygen) needed by bacteria in decomposing the organic wastes present in water.
B.O.D. increased = water polluted         B.O.D. ∞ input of organic wastes
If B.O.D. is increased dissolved oxygen is decreased in water. Higher amount of organic waste increase the rates of decomposition in water. O2 is rapidly consumed by microbes, thereby causing drop in D.O. content in water.

Dophnia is the indicator of B.O.D.

Biochemical oxygen demand [BOD] is the amount of oxygen taken up by the micro organisms present in water. BOD is measured by keeping a sample of water containing known amount of oxygen for 5-days at 20ºC in the dark. At end of this period the oxygen content is again measured. A high BOD indicates intense level of microbial pollution.

Fig.: Effect of sewage discharge on some important characteristics of a river

2. Chemical Oxygen Demand (C.O.D.) :
It is the oxygen requirement by chemicals for oxidation of total organic matter (biodegradable + non biodegradable) in water.
Note : C.O.D. value is always higher than B.O.D. value.

3. Biological magnification :

The non biodegradable heavy metals (Density > 5g/cm³) pollutant like Al, Hg, Fe, D.D.T., Pesticides, Phenolic compound ABS (Alkyl benzene sulphonate) are not decomposed by micro-organisms.

They get accumulated in tissue in increasing concentration along the food chain at successive trophic levels is called biological magnification. The highest concentration occur's in top consumer.

It occurs as the toxic substances accumulated by organisms cannot be metabolised or excreted and pass on to next higher trophic level. The most common biomagnification is of Hg and DDT. The DDT concentration is starts from 0.003 ppm in water, it can ultimatly reach 25 ppm in fish eating birds through biomagnification.

High concentration of DDT distrub calcium metabolism in birds, which causes thinning of egg shell and their permature breaking, eventually causing decline in bird populations. 

4. Eutrophication :

The process of nutrient enrichment of water and consequent loss of species diversity (or death of aquatic animals) is reffered to as eutrophication and lake is known as eutrophic lake. In this process presence of nutrients (Nitrogen and Phosphorous) in lake stimulates growth of algae (algal bloom) increase organic loading and bring about reduction in the oxygen content of water causing death of aquatic animals.

Eutrophication is the natural aging of a lake by biological enrichment of its water. Natural aging of a lake span thousands of years and lake finally converted into land due to deposition of silt. Pollutants from man's
 activities like effluents from the industries and homes can radically accelerate the aging process, this phenomenon is called accelerated eutrophication.

In past century many lakes are eutrophicated by sewage and agricultural and industrial waste. The prime contaminations are nitrate and phosphate. Which acts as plant nutrients, which over stimulate the growth of algae causing unsightly scum & unpleasent order and depletes oxygen dissolved in water which harm aquatic life. The other pollutants flowing in lake may poison whole population of fishes, whose deposition also depletes dissolved oxygen and ultimately leads to death of lake.

B.O.D. of Eutrophic lake is very high.

Water Pollution can be caused by the following man made sources
1. Household Detergents : The house hold detergents include the compounds of phosphate, nitrate, ammonium and alkyl-benzene sulphonate (ABS) etc. harmful substances which are gathered in water. Alkyl benzene sulphonate is non degradable, so its concentration increase which is harmful for aquatic life.

2. Industial waste : The wastes of industries are discharged into the running water of rivers and canals Industrial waste mainly contains inert suspended particles such as dust, coal, toxins like acid, base phenol cyanides, mercury, zinc etc. inorganic reduced material like-ferrous salts sulphide, oil and other residues of organic material and hot water. The water polluted by mercury, lead etc.
metals when used which caused disorganisation of nervous system. It means it produces insanity. The
 minamata disease was caused in Japan by eating of polluted fishes from the water polluted
 by mercury. So, many humans died because of this disease.
For the control of the industrial wastes and toxic components should be purified before draining into rivers lakes and ponds or sea. So the water pollutions by industrial effluents can be controlled by suitably treating the pollutants.

3. Sewage : Sewage contains highest amount of carbonic materials and biological material, as pollutants. These carbonic materials increase the number of decomposers like bacteria and fungus. The rate of reoxygenation is reduced as compared to deoxygenation in a water reserviors. The acceleration of microbial activity increases BOD of water. This indicates the essential amount of oxygen required for decomposition by bacteria.

Method of water purification :
Water (prevention and control of pollution) Act. 1974 passed by Government of India.
The industrial and municipal waste water are treated in "Effluent Treatment Plant" (ETP) Generally
following treatments are given in ETP.

1. Primary treatment : This physical process involves the separation of large debris (particles), followed by sedimentation in tanks.
2. Secondary treatment : This is a biological process and is carried out by microorganism. In this process, the waste water is pumped in shallow stablisation or oxidation ponds or activated sludge chamber, where the microbes oxidise its organic matter. The process results in release CO₂ and this CO₂ is used by algae in photosynthesis. In photosynthesis process algae release O₂.
3. Tertiary treatment : This physiochemical process removes turbidity in waste water caused by the presence of nutrients (Nitrogen, Phosphorus etc.), dissolved organic matter, metals, pathogens.

This step involves chemical oxidation of waste water by strong oxidising agents, such as
chlorine gas, perchlorate salts, ozone gas and UV radiations.
After tertiary treatment, the wast-water can be discharged into natural water sources or used for
irrigation.
Daphnia, trout fishes and larva of stone fly are sensitive to water pollution and show the
 intensity of water pollution.

A Case Study of Intergrated Waste Water Treatment :
1. Waste water including sewage can be treated in an integrated manner, by utilising a mix of artificial and natural processes. An example of such an initiative is the town of Arcata, situated along the northern coast of California.

2. Calloborating with biologists from the Humboldt State University, the towns people created an
integrated waste water treatement process within a natural system.

3. The cleaning occurs in two stages -

(a) The conventional sedimentation, filtering and chlorine treatements are given. After this stage, lost of dangerous pollutants like dissolved heavy metals still remains. To combat this, an innovative approach was taken and

(b) the biologists developed a series of six connected marshes over 60 hectares of marshland.

4. Appropriate plants, algae, fungai and bacteria were seeded into this area, which neutralise, absorb
and assimilate the pollutants. Hence, as the water flows through the marshes, it gets purified
naturally.

5. The marshes also constitute a santuary, with a high level of biodiversity in the form of fishes,
animals and birds that now reside there. A citizens group called Friends of the Arcata Marsh
(FOAM) are responsible for the upkeep and safeguarding of this wonderful project.

6. All this time, we have assumed that removal of wastes requires water, i.e, the reaction of sewage.
But what if water is not necessary to dispose off human waste, like excreta? Can you imagine the
amount of water that one can save if one didn't have to flush the toilet? Well. This is already a
reality. Ecological sanitation is a sustainable system for handling human excreta, using dry
composting toilets.

7. This is a practical, hygienic, efficient and cost-effective solution to human waste disposal. The key
point to note here is that with this compositing method, human excreta can be reycled into a
resource (as natural fertiliser), which reduces the need for chemical fertilisers. There are working
'EcoSan' toilets in many areas of Kerala and Sri Lanka.

==============================================================

Radioactive wastes - Environmental Issues, Biology, Class 12

RADIOACTIVE POLLUTIONS
The property of sudden emmission of the different particles (charged) and radiation (rays) by the
 decay of atomic nuclei is called radioactivity and the elements are called as radiactive elements.
The radioactivity of the atmosphere is increased by Atomic power stations and Atomic tests. Radioactivity
contributes to the pollution of air, water as well as soil and it proves extremely harmful to the organisms.

The various sources of radioactive materials as follows

Natural sources : Cosmic rays, radiation from the earth such as Radium-224, Uranium-235,
Uranium-238, Thorium-232, Radon-222, Potassium-40 and Carbon-14.

Man made Radiation : The radiations are released in the atmosphere during mining and purification
of Thorium and Plutonium, and in producing nuclear weapons etc.

Nuclear reactor and nuclear fuel causes pollution by radioactive radiation. The nuclear fuel and coolants are the sources of radioactive radiation. Radioactive waste is also most important radio active pollutants because these wastes are not dumped at particular or right place.

Other sources : Some of the radioactive elements (isotops) are used in experimental laboratories for scientific researches which causes radio active pollution. X-rays are also proved to have harmful effects. In month of April 2010, 6 peoples at Delhi affected by such radioactive pollution by coablt-60.

Harmful radiation are divided into two categories

(a) Non ionising components : Non ionising components such as UV radiation. UV radiations are harmful for living beings. These radiations causes harm to the DNA, RNA and protein. Higher concentration of U.V.  radiation can causes xeroderma pigmentosum disease. UV radiations causes destruction of hydrogen bonds in DNA.

(b) Ionising components : X-rays, α-particles, β-particles etc are ionising components. Ionising radiations are high energy radiations which release electrons from atoms and form a pair of negative and positive ions.

Ionising radiations cause physical weakness and sudden death of living beings. The effects like hereditary changes, mutations, tumours, cancer and developmental changes are seen due to radiations.

Excluding these, Iodine-131, Stronstium-90 are spreading in the environment through nuclear explosion and their effects remains for long duration. Iodine-131 reaches in the human body through the food chain and causes harm to the bone marrow, WBC, Lymph nodes and spleen.
Similarly, the lead to skin cancer, sterility and poorer eye sight. Stronstium-90 leads to bone
cancer and degeneration of tissues.

Control Measures : The competition of nuclear weapons should be completely banned to prevent radioactive pollution. An atomic bomb was first used in Hiroshima and then in Nagasaki in 1945 during the second world war and due to that genetic disorders are present even today therefore, such type of atomic blast should be avoided. Leakage of nuclear reactions has been totally plugged. Transportation, use and disposal of the radioactive fuels and wastes has to be handled carefully.

SOIL POLLUTION

Soil is also polluted through water and air. These pollutants are mixed into the soil through the rain water.

Such as H₂SO₄ acid formed by mixing of SO₂ with rainy water in the air. The fertilizers, pecticides and weedicides are being sprayed over the crops. All these are mixed with soil to produce harmful effects. The
growth of plants is inhibitated or reduced due to this type of pollution and sometime their death also take place.s Excluding these, soil pollution also caused by the disposal of house hold detergent sewage, flowering oils, radio active substances and hot water etc. The main pollutants of soil are D.D.T. and weedicides [2, 4D (2, 4 dichlorophenoxy acetic acid), 2, 4, 5-T (2, 4, 5-Trichlorophenoxy acid.)].

Case Study of Organic Farming

Integrated organic farming is a cyclical, zero-waste procedure, where waste products from one
process are cycled in as nutrients for other processes. This allows the maximum utilisation of
resource and increases the efficiency of production.

Ramesh Chandra Dagar, a farmer in Sonipat, Haryana, is doing just this. He includes bee-keeping, dairy management, water harvesting, composting and agriculture in a chain of processes, which support each other and allow an extremely economical and sustainable venture.

There is no need to use chemical fertilisers for crops, as cattle excreta (dung) are used as manure. Crop waste is used to create compost, which can be used as a natural fertiliser or can be used to generate natural gas for satisfying the energy needs of the farm.

Enthusiastic abut spreading infromtation and help on the practice of integrated organic farming.
Dagar has created the Haryana Kisan Welfare Club, with a current memebership of 5000 farmers.

Plant indicators : "Such type of plants which give additional information about the environment or habitat are called plant indicators". eg., Growing of Viola plants indicates the presence of Zinc in soil.

Ocimum shows presence of copper in soil. Silene (a plant) indicate presence of cobalt. The presence of Lichens shows that atmosphere is free from the pollutants like CO and SO₂ .

=======================================================

Solid Wastes - Environmental Issues, Biology, Class 12

SOLID WASTES
Solid wastes means everything that goes out in trash. Muncipal solid wastes are waste from homes,
offices, stores, schools, hospitals etc. which are collected and disposed by municipality. It comprise
mainly paper, food waste, plastics, glass, metals, rubbers, leather, textiles etc.

Generally, these wastes are burned. Sanitary landfills are adopted as the substitute for openbring
dumps in which wastes are dumped in depression or trench and covered with dirt.

But also cause harm as it cause danger of seepage of chemicals and cause pollution of underground water.
Whole solid waste can be categorised as :
(1) Biodegradable

(2) Recyclable

(3) Non-biodegradable

Plastic is non-biodegradable, so it use should be minimize by minimum use of plastic bag or use of
ecofriendly packaging material.

Electronic waste or e-waste are the irreparable computers, mobiles, electronic goods. E-waste are
buried in landfills or incinerates.

Over half of e-waste of developed world are exported to developing countries mainly China, India,
Pakistan where metals like copper, iron, silicon, nickle and gold are recovered during recycling process.

In these countries the peoples participate in recycling of e-waste are exposed to toxic substance
present in e-waste.

The ecofriendly recycling is only treatment of e-waste.

Case Study of Remedy for Plastic Waste :
A plastic sack manufacturr in Bangalore has managed to find the ideal solution to the everincreasing problem of accumulating plastic waste. Ahmed Khan, aged 57 years old, has been producing plastic sacks for 20 years. About 8 years ago, he realised that plastic waste was a real problem. Polyblend, a fine powder of reycyled modified plastic, was developed then by his company.

This mixture is mixed with betumen that is used to lay roads. In collaboration with R.V. Collage of Engineering and the Banglore City Corporation, Ahmed Khan proved that blends of Polybend and betumen, when used to lay roads, enhanced the bitumen's water repellant properties, and helped to increase road life by a factor of three.

The raw material for creating Polyblend is any plastic film waste. So, against the price of Rs. 0.40 per kg that rag pickers had been getting for plastic waste, Khan now offers Rs. 6.

Using Khan's technique, by the year 2002, more than 40 kms of road in Bangalore has already been laid. At this rate, Khan will soon be running short of plastic waste in Banglore, to produce Polyblend.

Thanks to innovations like Polyblend, we might still avoid being smothered by plastic waste.

======================================================

NATURAL RESOURCES AND THEIR CONSERVATION - Environmental Issues, Biology, Class 12

NATURAL RESOURCES AND THEIR CONSERVATION

 The materials or any component, that can be utilised by man and are necessary for welfare of life, which is
available in the natural environment in Atmosphere, Hydrosphere, Lithosphere is called natural resources.
e.g. O₂, Land, Soil water, Forest, Animals, Soil, microorganism.

Classification of natural resources :
1. Inexhaustible resources : Available in unlimited quantities, and the earth quantity may reamin unchanged
by human impact.
e.g. Solar Energy, Wind Power, Tidal power, Air, Geothermal Energy.
Its quality can be affected due to continuous increase in human population. e.g. Air pollution

2. Exhaustible resources : These are likely to be finished by human use or unsustainable uses.
It is further divided in two groups

(i) Renewable resources : Those which are being continuously consumed by man but renewed continuously by nature, always available if managed in a proper way, otherwise they may even get totally exhausted.
e.g. Biotic resources, forest, grazing animals, Rangeland, wild life, Agriculture crop system and
fresh water yield, soil etc.

(ii) Non renewable resources : They are not renewable after use and are not replaced by nature, can
not be regained.
e.g. Fossil fuel (Coal, Petroleum), Natural Gas, Nuclear energy, Biotic species, Minerals etc.
Nuclear energy is non renewable and unlimited resources.

HYDROSPHERE OR WATER RESOURCES

1. Water is the major constituent of the hydrosphere and covers 3/4 of the earth's surface.

2. The total volume of water in the hydrosphere is 1.4 bilion cubic kilometer [Km³], about 97.5 % is the ocean
 water, unsuitable for human use. Only 2.5 % is available as fresh water. About 1.97 % is stored in ice
 ocean (Polar ice) and glaciers and 0.5 % is ground water and soil mositure (0.01 %). The rest a [about
0.36 percent] is distriuted in lakes swamps, river and streams.

3. About 84 % of the total global evaporation occurs from ocean surface and 16 % from land surface.

Conservation and management of water :
Main approcaches for conservation of water are :

1. Reducing agricultural water wastage by increasing efficiency of irrigation.

2. Reducing water wastage in industry by recycling the used water.

3. Reducing domestic water wastage by cnstructing waste water treatment.

4. Rainwater harvesting by employing practices to store rainwater and recharge ground water.

5. Afforestation and protection of water sheds to improve water economy. Approaches to provide a sustainable supply of high quality water are :
(i) Construction of dams and reservoirs to ensure year-round supply of water, in addition, controlling flood and generating electricity.
(ii) Desalinisation of sea water and saline ground water and making it fit for drinking and other purposes.

LAND REOURCES
1. Earth's one-fourth area is formed by land.
2. About 4/5 of the land area is covered by soil.
3. At the beginning of 20th century, about 30 % of land in India was covered with forest but the end of the 20th
century, the forest cover reduced to 19.4 %. Out of 19.4 %, only 12 % area covered by dense forest.
Per capita forest area available in India is = 0.06 hec.
Per capita forest area avialble in world is = 0.64 hec.
In India 33 % forest area is recommended by national forest policy (1988).

SOIL CONSERVATION
Soil is the mixture of living and nonliving materials. Soil is only responsible for anchorage and sustainance of
the plants. The fertility of soil is reduced due to growing of plants again and again. Natural factors like water,
air etc. are also responsible for transporting the top soil and decrease fertility. This is called soil erosion.

Soil Erosion
The structure of soil is different at the different depths of land. Its some upper part is called top soil. This region is very essential for the growth of the plants. Its thickness is about 15-20 cm. This top soil contains humus and various micro-organisms which increase the fertlity of the soil. When this top soil removed by fast wind, fast rain, cyclone and running water then it is called soil erosion. The following reasons are responsible to minimise the fertility power of soil in nature.
(i) Shortage of mineral substance.
(ii) Leaching : The dissolved minerals go into the depth (lower layers) with water. Roots of the plants ususally
remain in top soil so the minerals are not available to the plants.

Soil conservation
Some management measures are essential to check the soil erosion. Accordiing to this some principle
are as follows :-
(i) To protect the soil form the drops of rainy water.
(ii) To stop the accumulation of water as well as stop the flow of water on the slopes.
(iii) To prevent the transportaion of soil particles.
(iv) To slow down the wind velocity on the surface of the earth.

=========================================================

Forest Conservation and Deforestation - Environmental Issues, Biology, Class 12

FOREST CONSERVATION
It is conducted by two methods
1. Protection or conservation foresty : By making national park and Biosphere Reserve.
2. Production or commerical forestry : It is two types
(a) Social forestry : To grow trees and shrubs on unused farmland, raod sides, rail sides, community land etc.
(b) Agro Forestry : woody species are grown in combination with herbaceous crops either at the same time
or in time sequence.
Taungya system : Growing agricultural crops between rows of planted trees.
Shifting Cultivation or Jhum Cultivation : It is a major cause of deforestation. Many tribal communities
practise slab and burn agriculture in tropical and subtropical regions of Asia. Africa and Oceania. This consists
cutting down trees and setting them or fire and raising crops on the resulting ash called “Juming” in north
estern India.

WET LANDS
Low lying area's covered with shallow water are called wet land's. The wet lands are transitions, zones
between terrestrial and aquatic area's. 6% of the world land surface is occupied by wet lands.
Marshes : Wetlands where grass - like plants dominate.
Swamps : Wetlands where trees or shrubs dominate.
Reverine forest : Periodically Flooded forest found in lowland along streams.
Mangrove is saltly water swamp

DEGRADATION BY IMPROPER RESOURCE UTILISATION AND MAINTENANCE
The degradation of natural resources can occur, not just by the action of pollutants but also by improper
resource utilisation practices.

(i) Soil erosion and desertification : The development of the fertile top-soil takes centuries. But, it can be removed very easiy due to human activities like over-cultivation, unrestricted grazing, deforestation and poor irrigation practices, resulting in arid patches of land. When large, barren patches extend and meet over time, a desert is created. Internationally, it particularly due to increased urbanisation.

(ii) Water logging and soil salinty : Irrigation without proper drainage of water leads to waterlogging in the soil. Besides affecting the crops, waterlogging draws salt to the surface of the soil. The salt then is deposited as a thin crust on the land surface or starts collecting at the roots of the plants. This increased salt content is inimical to the growth of crops and is extremely damaging to agriculture. Waterlogging and soil salinity are some of the problems that have come in the wake of the Green Revolution. This leads to 'sem' problem in many canal irrigated areas of India.

Deforestation :
Deforestation is the converstion of forested areas to non-forested ones. According to an estimate, almost
40% forests have been lost in the tropics, compared to only 1% in the temperate region. The present
scenario of deforestation is particularly grim in Inida.

At the beginning of the twentieth century, forests covered about 30% of the land of India. By the end
of the century, it shrunk to 19.4%, whereas the National Forest Policy (1988) of India has recommended
33% forest cover for the plains and 67% for the hills.

How does deforestation occur? A number of human activities contribute to it. One of the major reasons is the conversion of forest to agricultural land so as to feed the growing human population. Trees are axes of timber, firewood, cattle ranching and for several other purposes.

Slash and burn agriculture, commonly called as Jhum cultivation in the north-eastern state of India, has also contributed to deforestation. In slash and burn agriculture, the farmers cut down the trees of the forest and burn the plant remains.

The ash is used as a fertiliser and the land is then used for farming or cattle grazing. After cultivation, the area is left for several years so as to allow its recovery. The farmers then move on to other areas and repeat this process. In earlier days. when Jhum cultivation was in prevalence, enough time-gap was given such that the land recovered from the effect of cultivation. With increasing population, and repeated cultivation, this recovery phase is done away with, resulting in deforestation.

What are the consequences of deforestation? One of the major effects is enhanced carbon dioxide concentration in the atmosphere because trees that could hold a lot of carbon in their biomass are lost with deforestation. Deforestation also causes loss of biodiversity due to habitat destruction, disturbs hydrologic cycle, causes soil erosion, and may lead to desertification in extreme cases.

Reforestation is the process of restoring a forest that once existed but was removed at some point of time in the past. Reforestation may occur naturally in a deforested area. However, we can speed it up by planting trees with due consideration to biodiversity that earlier existed in that area.

Case study of People's Participation in Conservation of Forest
People's participation has a long history in India. In 1731, the king of Jodhpur in Rajasthan asked one of his ministers to arrange wood for constructing a new place. The minister and workers went to a forest near a village, Khajadli inhabited by Bishnois, to cut down trees.

The Bishnoi community is known for its peasful co-existance with nature. The effort to cut down trees by the kings was thwarted by the Bishnois.

A Bishnoi women Amrita Devi showd examplary courage by hugging a tree and daring king's men to cut her first before cutting the tree. The tree mattered much more to her than her own life.

Sadly, the king's men did not heared to her pleas, and cut down the tree along with Amrita Devi.
Her three daughter and hundreds (total 363 peoples of other Bishnois followed her, and thus lost their lives saving trees.

Nowhere in history do we find a commitment of this magnitude when human beings sacrificed their lives for the cause of the environment. The Government of India has recently instituted the Amrita Devi Bishnoi Wildlife Protection Award for individuals or communities from rural areas that have shown extraordinary courage and dedication in protecting wildlife.

Government of India insituated Indra Gandhi Priydarshni; Vraksh Mitra Award for forest conservation.

You may have heard of the Chipko Movement of Garhwal Himalayas. In 1974, local women showed enormous bravery in protecting trees from the axe of contractors by hugging them. People all over the world have acclaimed the Chipko movement.

Realising the siginificane of participation by local comunities, the Government of India in 1980s has introduced the concept of Joint Forest Management (JFM) so as to work closely with the local communities for protecting and managing forests. In return for their services to the forest, the communities get benefit of various forest products (e.g., fruits, gum, rubber, medicine etc.) and thus the forest can be conserved in a sustainable manner.

SPECIAL POINTS

WILDLIFE ORGANISATIONS

MIC [Methyl Isocyanate] was released in Bhopal gas tragedy on 3rd December 1984. Which is used in the production of "Savin" insecticide in Union Carbide.
Tetraethyl lead and tetramethyl lead are formed by combustion of petroleum. They are known to hamper haemoglobin formation.
The disease produced by use of lead polluted water is called as plumbism.
Lead caused nervousness anaemia in human beings. It also damages kidney.
Lead concentration in blood is considered alarming if it is 10 μg/500 ml.

Common dust disease is known as Pneumoconiosis.
Disease due to cotton dust in testile workers is - Lung fibrosis or Byssinosis.
Disease due to coal dust - Anthracosis.
Disease due to asbestos dust - Asbestosis.
In stone grinders disease due to silica dust - Sillicosis.
In iron mill disease due to iron dust - Siderosis.
Cadmium causes anaemia, hypertension, damage to liver and kidneys. In Japan it caused bone softning or skeleton deformitcis called Itai-Itai disease or Ouch-Ouch.

Stone leprosy is caused due to acid rain because due to acid rain outer surface of metals, marbels
and stone destroyed.

Blue Baby disease : This disease is caused by the high amount of nitrate in water. It is also known
as Methaemoglobinaemia or cyanosis.

Hypertension and Uremia : Caused by Copper.

Arsenic : It causes black-foot disease and poisoning in fodder plants which are eaten by live stock and causes their death.

Fluorides : The higher concentration of flouorides causes chlorosis or necrosis in tips and margin of leaf (leaf lamina). The compounds of fluorine reach in the animals through the fodder and causes abnormal calcification of teeth, this is called Fluorosis.

Note : The experts hold that the maximum level of fluoride which the human body can tolerate is 1.5 parts per million (ppm). When ingested in excess over a long period of time causes "Fluorosis".

EL Nino effect : It is the process in which water of Pacific ocean get warm, in this process warm water
currect flow to equator & peru in between 5 to 8 year at christmas time. Effect of EL Nino is flood, drought and mansoon damage in India.

Cesium (Cs) accumulates in muscles and causes muscular pain.

Strontium-90 is radioactive element which causes Leukamia and bone cancer.

Iodine isotope-131[I¹³¹] causes damage of RBC, bone marrow, Lymphnodes and Skin cancer.

Tobacco and smoke contain seven poly cyclic hydrocarbon and Radio active Polonium-210, which is
carcinogen and causes Lung cancer.

Aldehydes produce irritation in the gastrointestinal and respiratory tract.

Phenols caused damage to spleen, Kidney, liver and lungs.

D.D.T. caused Cerebral haemorrhage and malfunctioning of sexual maturtity.

Largest source of air pollution (80%) caused by automobiles in the cities i.e., CO(77.2%). Nitrogen oxide (7.7%), Hydrocarbons (13.7%), SO2, NH3, Aldehyde and Lead [in the form of Pb(C₂H₅)^₄ and
Pb[(CH₃)₄ as antiknocking agent]. Lead is an air pollutant. Automobiles also reduce atmosphereic
O2 which is utilised in oxidation.

Particulate pollutants [soot] are Carcinogenic [Cancer causing].

The particulate matter released to the atmosphere by mechanical operations include a number of trace
metals contained in the flyash. Some of harmful trace metals are Antimony, Arsenic, Beryllium,
Cadmium, Germanium, Lead, Mercury, Nickel, Selenium, Vanadium and Yttrium.

Conference on human environment in 1972 held at Stockholm.

International Biological Programme (IBP) 1967-74.

The united Nations, conference on desertification was held in Nairobi (Kenya) in 1977 under the United Nations Environment Programme (UNEP)

Type of Lakes -
(i) Eutrophic lake - They are shallow water lakes which contain high amount of organic materials and nutrients. They have little O2 because decomposers rapidly use it up. Chironomous larva are commonly present in it.
eg., Dal lake of Kashmir

(ii) Oligotrophic lakes - These are deep lakes which have less amount of organic materials and nutrient.

(iii) Dystrophic lake - Maximum amount of undecomposed organic matter is present.
eg., Marshy lake.

Third pollution or land scape pollution : To make Fertile-land barren by dumping wastes.
eg., ash, insustrial waste.

Incineration : Solid wastes burning in presence of oxygen.

Pyrolysis : Solid wastes burning (combution) in the absence of oxygen.

Flu gas : Gas which release of from chimnies.

Plume : Smoke which release from chimnies.

Hydro thermal vents : These are hot water springs in the deep ocean having high concentration of H₂S, ocean water oxidizes H₂S producing energy which is used by bacteria, Filter-Feeders (clams) eat the bacteria so that this food chain based on chemical energy.

Phytotrons : A such type of house where plants are grown in controlled environment.

Hydrocarbon : Are also known as volatile organic carbons (VOC).

Snow blindness : In human eye cornea absorbs U.V.-B radiation, and a high dose of U.V.-B radiations causes inflammation of cornea, called snow-blindness cataract.

Electronic wastes is also called e-wastes.

Ganga Action plan for controlling pollution in ganga (1985) included city :

(i) Kolkata

(ii) Kanpur.

Land of maximum wind mills - Netherland.

Largest wind will complex in India, Lamba (Gujrat)

At 50 ppm, CO converts 7.5% of haemoglobin in to carboxy haemoglobin with in 8 hours.

Maximum grean house gas released by - USA

Cotton dust is an important pollutant in Ahmedabad.

CEPHERI : An institution established in India to check pollution i.e., "Central Environmental and Public Health Engineering Research Institute" (CEPHERI).
This institution submits the measures on the basis of results of detailed survey.

NEERI : National Environmental Engineering Research Institute - Nagpur.
(Environmental plannig organisation is related with NEERI)

IPCC : The "Intergovermental Panel on Climate Change".

I.A.P. : Index of atmospheric pollution prepared with the help of lichens.

I.W.P. : Index of water pollution, prepared by Daphnia, E.coli, Trout.

M.P.N. : Most probable number of E.coli in water.