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It is a series of shock waves left behind by a supersonic Jet flying at a speed. It produced sudden rattling of windows and doors. Building many develop cracks.

Excess growth of certain phytoplankton due to excess nutrients in water causes Deteriorates water quality, leads to fish mortality.

It is the increase in the concentration of certain toxic chemicals like DDT at successive trophic levels through food chain is called bio magnfication.

Nutrient enrichment in water bodies leading to depletion of oxygen and loss of life supporting Environment.

Increase in the concentration of certain toxic chemicals at successive trophic levels.

Effect of air pollution:

• Cause injury to all living organisms. 
• Reduce growth and yield of crops. 
• Cause premature death of plants. 
• Affects the respiratory system of human being. 
• Particulate size 2.5 micrometers or less are responsible for breathing and respiratory symptoms like irritation, inflammations and damage to the lungs and premature death. 

Pollution caused by thermal power plant: 

• Sources of particulate matter: thermal power plant, smelters 
• These plants release particulate matter and gaseous air pollutant. 
• A harmless gas released by these plants is Nitrogen and Oxygen.

Biological Oxygen Demand is the measure of organic matter in any water sample.

Water logging and soil salinity.

DDT disturbs calcium metabolism in birds, thinning of egg shell and premature breaking of Eggs lead to decline in bird population.

Ecosanare the toilets which use compositing method for ecological sanitation.

Farmers cut down the tress, burn, use cattle for grazing and then allow the land to recover.

Are lethal even at lower doses and cause damaging disorders. 

To protect and improve the quality of our environment (air, water, and soil)

The aim of auto fuel policy is to decrease the emission of sulphur, carbon monoxide and aromatics content in petrol and diesel fuels. Euro-IV norms- April 1, 2010.

1. Poly blend and bitumen.

2. The raw material for creating Poly blend is any plastic film waste. So the accumulation of plastic wastes can be controlled.

1. It change the colour and quality of water and causes the mortality of fish

2. Presence of large amounts of nutrients in waters also causes excessive growth of planktonic(free-floating) algae, called an algal bloom

3. This results in the decrease of D.O. in water.

• It is a fine powder of recycled modified plastic. This mixture is mixed with bitumen used to lay roads. Raw material – Plastic film waste
• Blends of poly blend and bitumen, when used to lay roads, enhances the bitumen’s water repellent properties and helps to increase road life.

2. Irreparable computers and other electronic goods are known as e-wastes. Burried in land fills or incinerated.

1. Sulphur be controlled at 350 ppm in diesel and 150 ppm in the petrol.

2. Aromatic hydrocarbons are to be contained at 42% of concerned fuel.

1. Jhum cultivation.

2. In Jhum cultivation or slash & burn cultivation, forest land is converted to agricultural land by cutting and burning trees, ash obtained is used as fertilizer for crop cultivation and other land is used for grazing cattle. The process repeated and it leads to deforestation.

Greenhouse gases (CO₂, CH₄, N₂O, CFCs) allow the solar radiations to enter but prevent the escape of heat radiations of longer wavelength. The absorbed radiations again come to earth’s surface and heat it up. Increase in the level of these greenhouse gases allow the heat waves to reach earth but prevent their escape and thus the earth becomes warm. There is gradual continuous increase in average temperature of earth surface leading to global warming.

(a) CO₂ cycle
(b) By burning fossil fuel
(c) Global Warming
(d) Melting of glaciers and slow rise in sea level, submerging of low lying islands.
(e)

• Limiting the use of fossil fuels
• Increase the vegetation cover

The thin layer of ozone around the atmosphere that prevents entry of harmful UV rays in earth’s atmosphere is called ozone shield.

(i) (a) N₂O
(b) CH₄
(ii) Increase in green house gases (GHGs) results in increased green house flux or trapping long wave radiations and sending them back to earth. It increases atmospheric temperature called global warming. High atmospheric temperature results in melting of ice caps and glaciers.

UV rays act on CFCs and release chlorine. These chlorine atoms act on ozone to release O₂, resulting in ozone layer depletion.

Ozone hole is the thinning of ozone layer is stratosphere and it is marked over the Antartica region. It develops every year late August and early October.

In the stratosphere the VU rays act on the CFCs and release chlorine atoms. There chlorine atoms degrade the ozone layer by acting as a catalyst. Since the chlorine atom are not consumed in the reaction the CFCs have a permanent and continuing effect on ozone holes.

Depletion of ozone widely in the stratosphere, particularly over the Antarctic region result in formation of thinned ozone layer called ozone hole.

Sunlight is necessary for ozone degradation and it is available only during spring.

Green house effect is a naturally occurring phenomenon, in which the short wave radiations of solar energy are absorbed and long wave radiations are reflected by the earth, but reabsorbed by certain gases and increases the, temperature of earth’s surface and atmosphere.

Those agents which bring undesirable change in the physical chemical and biological characteristics of air, water and soil are called pollutants.

“Protect and improve the quality of our environment i.e. air, water and soil”.

To control emission of ozone depleting substances.

Enough time gap is not being given for the natural process of recovery of land from the effect of cultivation. 

When non-degradable substances enter the food chain, they do not get metabolized or broken down or expelled and instead get transferred up the tropic levels of the food chain. During this process, they show an increase in concentration which is referred to as biomagnification. This results in increased toxicity and may even be lethal. This phenomenon is well established for mercury and DDT.

Yes, this is true that if the dissolved. O₂ level falls to zero the water will get septic. The presence of organic pollutants in the water bodies results in lowering the level of dissolved oxygen even upto zero.

N₂O, CFC, CH₄, CO₂.

The forest plants fix a lot of CO₂ and thus have a lot of carbon in their biomass. The deforestation therefore results in the increased concentration of CO₂ in the atmosphere which may result in the global warming.

(a) C₂H₄ →N₂O → CFC → CO₂ / N₂O → CFC → C₂H₄ → CO₂ (Highest)

(b) (Global warming) → Rise in Atmospheric temperature → polar ice melts → increase in sea level → coastal land mass submerge. 

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

UV rays act on CFC's, release Cl atom, which act on ozone to release O₂ resulting in ozone layer depletion/causing ozone hole.

Detailed Answer :

The ozone layer is getting depleted by the action of CFCs (Chlorofluorocarbons) used as coolant in refrigerators. UV rays act on CFCs releasing Cl atoms. In presence of Cl (catalyst), ozone degrades releasing molecular oxygen (O₂). This causes ozone depletion.

(a) The ozone formed in the stratosphere is called 'good' ozone, as it acts as a shield and absorbs the ultraviolet radiation from the sun.

The major ozone-depleting substances are chlorofluorocarbons, which release active chlorine in the presence of UV. The chlorine atoms degrade ozone into molecular oxygen.

CFCl₃ + UV(C) → CFCl₂ + Cl

CFCl₂ + UV(C) → CFCl + Cl

Cl + O₃ → ClO + O₂

ClO + O₃ → Cl + 2O₂  

(b) (i) The thinning of the ozone layer results in an increase in the UV radiation reaching the earth's surface. A 5 per cent increase in UV radiation.

(ii) In humans, the increased UV radiation increase the incidence of cataract and skin cancer (including melanoma) and diminishes the functioning of the immune system.

(iii) Elevated levels of UV radiation affect photosynthesis as well as damage nucleic acids in living organisms. UV radiation inhibits photosynthesis in most phytoplankton as it penetrates through the clear open ocean water.

(iv) This, in turn, can affect the whole food chain of organism that depends on the phytoplankton.

Accelerated eutrophication occurs due to the passage of sewage and run-off from fertilized fields into ponds, lakes and other water bodies. Nutrients present in sewage and fertilizers causes dense growth of plants and planktonic algae. 

Consequences of accelerated eutrophication : 

(i) Eutrophic water bodies support excessive growth of floating plants, e.g., water hyacinth is one such plant that sometimes chokes ponds, lakes and rivers. 

(ii) Due to increase of algal blooms, there is drastic decrease in oxygen replenishment inside water that kills aquatic animals.

The natural ageing of a lake is termed as eutrophication. In a young lake, the water is cold and clear, supporting little life. With time, streams draining into the lake introduce nutrients such as nitrogen and phosphorus, which encourage the growth of aquatic organisms. As the lake's fertility increase, plant and animal life flourishes, and organic remains begin to be deposited on the lake bottom. Over the centuries, as silt and organic debris pile up, the lake grows shallower and warmer, with warm-water organisms supplanting those that thrive in a cold environment. Marsh plants take root in the shallows and begin to fill in the original lake basin. Eventually, the lake gives way to large masses of floating plants (bog), finally converting into land. Depending on climate, size of the lake and other factors, the natural ageing of a lake may span thousands of years.

Pollutants from man's activities like effluents from the industries and homes can radically accelerate the ageing process. This phenomenon is called cultural or accelerated eutrophication. 

(a) When sewage is discharged into a river, microorganisms involved in biodegradation of organic matter in the receiving water body consume a lot of oxygen, and as a result there is a sharp decline in dissolved oxygen downstream from the point of sewage discharge. This causes mortality of fish and other aquatic organisms. 

(b) The presence of large amounts of nutrients in waters also causes excessive growth of planktonic algae, called an algal bloom, which imparts a distinct colour to the water bodies. Algal blooms cause deterioration of the water quality and causes fish mortality. Some bloom-forming algae are extremely toxic to human beings and animals.

Advantages of CNG : 

(i) burns efficiently/less unburnt residues. 

(ii) Cheaper than petrol/diesel. 

(iii) Causes less pollution. 

(iv) cannot be adulterated. 

(v) cannot be siphoned by thieves.

Detailed Answer: 

CNG is better than petrol and diesel because : 

(a) CNG burns most efficiently and very little of it is left unburnt. 

(b) CNG is cheaper than petrol or diesel, cannot be siphoned off by thieves and adulterated like petrol or diesel. 

Pollutants from human activities / effluents from industries / effluents from home / sewage / agricultural (chemical) wastes radically accelerate the ageing process.

The advantages are as follows : 

(i) Unleaded petrol does not release lead compounds from exhaust fumes into the atmosphere and causes less pollution. 

(ii) It does not emit harmful compounds, it helps in preventing health diseases like bronchitis, asthma and lung diseases. 

(iii) It allows catalytic converter to remain active.

The excess growth of planktonic algae that causes colouration of water is called algal bloom. Nutrients present in sewage and fertilizers cause dense growth of plants and planktonic algae. Soon planktonic algae increase in number and impart a characteristic colouration to water. Algal bloom is toxic to animals and humans. It blocks light for submerged plants. There is a drastic decrease in oxygen due to which animals die.

(i) Biochemical oxygen demand (BOD) refers to the amount of the oxygen that would be consumed if all the organic matters in one litre of water were oxidized by bacteria. 

(ii) Effects on aquatic life: 

(a) High BOD causes high mortality rate among aquatic animals. 

(b) The excessive nutrients facilitate algal growth causing algal bloom. 

Eichhornia crassipes is an aquatic weed that grows abundantly and very fast in eutrophic water bodies and imbalances water ecosystem. It causes oxygen depletion leading to death of aquatic life (eutrophication).

Landfill sites are getting filled very fast due to large amount of garbage generation. Also underground water resources may get polluted due to seepage of chemicals.

Excessive nutrients in a freshwater body cause fish mortality due to the following reasons : 

(a) Depletion of dissolved oxygen. 

(b) Increase in toxic material in water body