UNIT 7: Disaster Management

Disaster Management

Q: From which year was awareness about disaster started by the U.N.O?

Ans :  1990-2000.

Q: Which Indian organization is contributing to disaster management?

Ans : Home Ministry, Central Aid and Rehabilitation Department.

Q:  In which year was a course on disaster management included in the CBSE curriculum.

Ans : 2005

Q: What would you do if during a disaster electricity fails?

Ans : There should be an alternative provision for it. Solar energy and other such kind of energy should be utilized for it.

Q: Do you see any change of mind in the case of residents of disaster affected areas?       

Ans : Can be possible                             

Q: What is the role of regional disaster management?  

Ans : Map of hazardous zone

Q: What do you mean by disaster management? Explain.

Ans: A disaster, whether it is a man made or due to natural causes, may have devastating effects, We cannot stop the loss or damage caused by disaster. But it can be reduced to some extent. This is called disaster management. Disaster is a sudden occurrence and it does not give any kind of warning before its occurrence. Earthquakes, floods, soil erosion, big industrial accident, deforestation caused by fire, volcanic eruption, cyclical storm, cyclical sea waves, hail storm, Tsunami Tides, thunder­storm, drought, terrorist attack, natural or man made accidents are all different forms of disaster. Men's varicc s activities are to some extent responsible for the occurrence of a disaster that causes loss or damage to lives and property But precautions/preventions if taken in advance can reduce the impact of disaster to some extent. For this we should take methodical and pre-planned steps. Skilled planning can also prevent in reducing the impact of disaster. Different kinds of disaster need different measures or precautions to prevent or reduce their impact. The U.N.O in 19-87 took a very important proposal in this regard. According to this proposal, the 1990-2000 decade was declared as the International Natural Disaster Prevention decade, this proposal consists of the following:

a.     Every state should increase its capability of predicting a disaster and organizing its management.

b.     The loss or damage caused by Natural disaster should be minimized. The present and future scientific measures for prediction of such disasters should be expanded.

c.     Analysis of natural disaster, its solution and future prediction should be given the priority..

d.     There should be a provision of possible guidelines and planning regarding disaster management.

Q: Write a short note on the measures to be taken during a disaster.

Ans: There should be proper planning for the post disaster measures so that the loss can be minimized. Some of the steps that are to be taken after a disaster are—

a.     To rescue people from the calamity as fast as possible (ii) To identify the living, injured and the dead people and to keep their records.

b.     To keep the communication network" from getting disrupted. To guard against the possible theft of essential articles.

c.     To arrange temporary relief camps and to provide drinking water, medicine and electricity.

d.     To ensure the supply of essential things like food, woolen/ warm clothes, bedding, utensils etc.

e.     To ensure adequate transport facilities in the affected areas. To check the loss of lives and damage.

f.      To arrange the rehabilitation of the affected people and to take steps to bring back normalcy.

g.     To prepare a detailed report of loss and damage.

Relief Camps: Establishing and organizing relief camps after a disaster takes place is very important. The affected people need special help for rehabilitation after a disaster. For instance, after a disaster, first aid, drinking water, food, seeds for cultivation etc are some of the important items needed by the disaster affected people. Under these circumstances the government and NGOs should act together in organizing the relief camps and the government should provide the necessary first aid, relief materials, rescue materials, food and medicines to the organizations managing the relief camps.

Resources: During the disaster period the flow of required funds to deal with the loss and destruction will depend on the supply of the funds by the public and private organizations. To ensure the flow of . funds in the post disaster periods the following steps need to be taken:

a.     Every government should have some special funds to be spent for relief measures for disaster.

b.     It should be strictly monitored so that the funds are. utilized only for the disaster affected areas and for the specific purpose. The amount offund needed for pre- disaster and post disaster periods will be determined by proper guidelines

c.     Special insurance schemes should be made for disaster prone areas.

d.     Special funds are to be allotted for relief measures (v) The various industrial and commercial organizations, educational institutions ,private companies etc are to be encouraged for forming relief funds.

e.     The financial institutions disbursing loans for constructing houses should ensure that necessary precautions are taken in constructing house.        

Things that are Needed During a Disaster : During the post disaster "period certain essential things are required and providing these essential things is one of the major tasks. Some of the essential things are- food, water bottles, warm cloths, radio, paper, pen, old newspapers, soap, tooth paste, tooth brush, things that are used by small kids, heavy shoes, candle, knife, etc.

To provide, the above mentioned things, disaster management committees should appoint some organizations and trained workers who can act and distribute the relief materials as per requirement to the victims.

Providing Relief after a Disaster: To provide relief after a disaster is the primary responsibility of the National Crisis Management Committee under the central Government. Apart from that, various social groups and organizations have been playing an important role. It is essential to have co-ordination among all these groups to mitigate a disaster. Particular attention is to be given to the following in the post disaster period:

(i) Improvement in transport and communication

(ii) Providing safe drinking water

(iii) Maintaining proper electricity, telephone and sanitation

(iv) Managing the required food, shelter and clothes,

(v) To keep accurate account of loss and damage

(vi) To ensure the supply of seeds for cultivation and other facilities.

Q: What is an emergency aid? Discuss some emergency aids during a disaster?

Ans : After a natural disaster, emergency services should be provided to the living and the injured people or animals who are badly affected by disaster. Whether an earthquake or any other form of disaster occurs or not, the level of preparedness of the disaster management authority department depends on how they keep ready the materials for rescue operations, how the damage or loss of lives is controlled and hotf? far they could-'4flswe the supply of drinking water, electricity, first aid; public relation and emergency services.

(i) Supply of Water: In case-of disaster, like flood, supply of drinking water is necessary and for that the mouth of the tube well should be closed and bleaching powder is to be put in the well etc. Water should be taken after boiling and if required alternative wafer supply is to be arranged.

(ii) Supply of Electricity: Usually electricity is disrupted during and after the disaster Therefore there should be an alternative provision for it. Alternative sources of power such as solar energy should be utilized for it. Electricity should be restored immediately. The electricity department should be prepared to restore.etectricitjvFor this, special training should be given to the employees. During a disaster, there is a possibility of short circuit to avoid that the buildings should have provision for fire - extinguishers. If possible, the supply of electricity should be stopped for that period. Torch light should be kept ready by everyone so that it can be used during the disaster. Additional battery set, torch light, hurricane lamp are to be kept ready.

(iii) Infrastructure: Generally, during a disaster, infrastructures and the roads in particular suffer extensive damage. In case of Assam, flood affects the roads and causes communication problems. Storm destroys me newly built roads. Therefore life Public Works Department should remainprepared to face such an eventuality of loss or damage caused by hazards. The earthquake in 1950 in Assam brought massive destruction to the railway tracks and caused big craters on the roads. The engineers and the staff of the PWD Department should be given proper training to remain vigilant against disasters and it is one of the important aspects of disaster management.

(iv) Relief Camps: After a disaster organizing relief camps and their- management become absolutely necessary. In particular during floods, shifting the flood affected people) and animals to higher grounds is imperative. Volunteer groups] should be formed for managing the relief camps,. Separate toilets for males and females, drinking water, medicine, bleaching powder, brooms, tent, dry food, gas lamp, torch etc are; necessary. These are the some of the things are to be arranged. The names of the refugees in relief camps should be systematically recorded. Special care needs to be taken fox-women ,children, elderly persons and who are sick.

(v) First Aid : Sudden disaster causes loss of human lives, physical injuries, and also diseases. Sometimes dispensaries are also affected. So to mitigate such disaster, some medicines and trained staff should be made ready.. First aid kit should be kept ready and such kits contain: Cotton cloth and pashmina cloth

(a)    Adhesive tape

(b)   Crepe Bandage

(c)    Sterile dressing

(d)   Triangular Bandage

(e) Thermometer

(f)    Scissor

(g) Glasses/ Gloves

(h) Soap

(i) Pain reliever

(j) Antacid

(k) ORS Packet

Along with the doctor, there should be an ambulance. If required, provision should be there to shift patients from relief camps to hospitals for better treatment. It is essential to form a group for prevention of contagious diseases and the members should be given proper training for the purpose. Besides, necessary food items are to be kept in store for future use if an epidemic occurs.

Q: Explain with examples the role of voluntary organizations and the society in general in disaster management?

Ans : In order to survive at the time of disasters it is important for the various communities in the society to remain alert. In this case, the NGOs are expected to take important steps. Those who are engaged in disaster management are to be properly trained and well prepared. In this respect the participation of voluntary organizations, NGOs and sections of the society may make positive impact. The voluntary organizations and the different communities need to share mutual cooperation for this. For its effective implementation the concerned people are to be particularly responsible for and aware about the immediate rescue operations , rehabilitation and improvement of the environment. For this is needed a year long plan of action as well as the competence to tackle the situation immediately. The voluntary organizations should remain ever ready to create an awareness among the different sections of the society. For example, during the monsoons advance warning about floods about to occur, relief steps to recover the losses etc can be imparted to the people besides ensuring the distribution of relief materials, medicines, seeds and othefrthings. The poor people have to suffer untold miseries during a disaster, caused by destruction of houses and land becoming unfit for cultivation. The voluntary organizations are to extend both long term and short term help in this situation.

Q: Write a short note on Regional Disaster Management and Planning Commission.

Ans : Disaster management in general is a united effort of different departments through effective coordination. National Disaster management involves the planning for preparedness, prediction, warning for disaster, relief and rehabilitation, repair and reconstruction. For this different departments are to be involved at different levels and made ready through proper training for disaster management. The administrators, scientists, planning officers and various sections of the society have to play a vital role in this. Organisations and various social institutions should be engaged in coordinated work before and after a disaster. For this in different levels, training is to be conducted for readiness for a disaster. In this regard, administration, (Science; planning commission, NGO and various communities play a very important role. Already Natural Hazard Management Authority (NHMA) has identified probable hazards and have informed public. This organization of govt, of India has adopted various schemes end works in association with NGOs in this regard. It includes baps of hazardous risk zones, etc. In urban areas, guidelines of hazard proof houses and bridges are to be prepared.

UNIT 6: Concept of Disaster

Concept of Disaster

Q: Give a definition of disaster.

Ans : "Disaster" is sudden, unexpected and adverse natural or manmade event causing significant physical damage, loss of life or property, including permanent changes of the natural environment.

Q: True of false.

(a)     Disasters are the responsible to the hazards.                                    Ans : True.

(b)     Vulnerability is the probability of occurrence of a hazard.                    Ans : False.

Q: Fill in the blanks -

According to Peter Timmerman, "Vulnerability is the degree to which system may react, adversely to
the occurrence of a   .................. ".

Ans : Hazardous event.

Q: What are the main causes of flood?

Ans  :     (a) Natural causes (b) Manmade causes

Q: Write about the steps involved in the process of structural flood mitigation.

Ans : (a) Storage reservoirs  b)  Cutting of sinuses   c) Diversion of flood   d) Embankments

Q: Discuss the anthropogenic causes of flood.

Ans : (a) Deforestation  b) Urbanization  c) Breach of Dams/Embankments  d) Reservoirs  e) Agricultural practices       

Q: Write the definition of earthquake.

Ans : The earthquake is a vibration of the surface of j the earth with rocking energy of wave motion which is capable of shaking the buildings apart and causing gaping fissures to open up in the ground.

Q: Discuss the secondary effects of earthquake.

Ans : (a) Perceptible snaking, Seiche in rivers and ponds, Tsunami, Swaying of bridges, Shaking of buildings. Disaster

Q: Fill in the blanks :

(a)  Prolonged   drought   like   condition   leads   to   unemployment of farmers.

(b)  Tsunami is a Japanese word of which 'tsu' means  harbor and 'namee' means wave.  

(c)  The release of liquid petroleum hydrocarbons causes oil spill problem in water bodies.

(d)  In oil spills plumage penetrates through the feathers of a bird and affects its activities.

(e)  Oil   can   directly affect the invertebrates   by altering its   metabolic activities.

Q : Write in brief the natural causes of drought occurrence.

Ans : (a) Less amount of water vapour in the air due to the occurrence of heavy rainfall and hail storms results in dryness of the air. This sometimes causes drought.

(b) Wind is another natural factor which helps in the shifting of air masses.

Q: Write the definition of volcano.

Ans : Volcano is essentially a fissure of vent, communicating with the interior, from which erupt the flows
of lava, fountains of incandescent spray or explosive bursts of gases and volcanic ashes.      

Q: Write true or false.

a.     Volcanoes are always associated with the weaker zones of the earth's crust.             Ans : True.

b.     Volcanic eruptions and fallout of dusts and ash cause mass extinction of a few species.         Ans : True.

c.      Chernobyl disaster was a nuclear power plant accident.                                                      Ans : True.

d.      Oil spills cannot affect plants.                                                                                         Ans : False.

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Q. Bring out the differences between hazard and disaster.      

Ans : (i) Hazard: Environmental Hazard can be defined as those extreme events (anthropogenic/natural) which may cause catastrophic damage to property and loss of lives and degradation of environment. Hazards are considered the processes orthe causal factors resulting from most extreme events.

(ii) Disasters: Disasters are the results of-these extreme events, The intensity of the environmental disastter is always measured in terms of the total damage done to human lives, property and the environment. Disasters are the results of hazards and are very rapid and instantaneous. Such events cause great damage to human society.

Q. Elaborate on the structural and non structural mitigation measures for flood disaster.

Ans : Structural measures :

a.     Storage reservoirs: The volume of water during the flood may be reduced through a series of engineering devices such as construction of storage reservoirs which help in irrigation as well as power generation.

b.     Straightening of bends: The existence of too many of bends in the highly sinuous and meandering rivers retard the quick disposal of water. So, it may be necessary to straighten the meandering courses of a river by performing artificial cutoff of individual bends so that flood discharge may move downstream without causing flood along its banks.

c.     Diversion of flood: Flood diversion system implies the diversion of flood water in low lying areas through artificially constructed channels bordered by artificial dykes so that the devastation of floods can be reduced.

d.     Embankments: Embankments, dikes and flood walls are used to confine the flood water with the valley or within a narrow channel. These engineering works include the building of artificial levees of earthen materials along the river banks. These are considered as short-term measures for flood management. If these structures are used for a longer time, their usefulness is greatly reduced in managing flood flows.
Stone spurs are also used to protect the towns; cities and other populated areas from severe erosion during flood. Semi permeable spurs, pile spurs are also constructed to protect against flood and erosion.          

Non structural measures:

a.     Afforestation: It is the first step for controlling floods. Forest prevents the rain water from directly coming into the land. Rain waterfalls through tree leaves on the ground and forests also help in more percolation of rain water and reduce the surface run off. It significantly reduces soil erosion and helps in reducing the frequency of floods.

b.     Flood forecasting and early warning system: Flood control organizations and forecasting centers set up in various parts of India help in the forecasting of floods in river basins like the Ganga, Brahmaputra and their tributaries. These flood forecasting centers collect the data regarding rainfall, and the level of flood water etc. and people living in the lower basins' against the possible threat of flood.

c.     Zoning of flood prone areas: The flood prone areas are classified into certain zones based on the levels of risk the different areas have and the probability of hazard they face. This type of classification or zonation is useful in the management of flood hazard in the flood prone areas.

Q: What are the primary, secondary and transient effects of earthquake?

Ans : Primary effects : (i) Regional geological changes, (ii) Displacement of arid cracks in any matter (iii) Fissures and cracks in buildings, roads etc. (iv) Elevation and depression of land, (v) Accumulation of water, (vi) Change in the direction of river current. (vii) Formation of stream tremors iii ponds and water bodies (viii) Displacement of well and spring.

Secondary effects: (i) Landslide (ii) minor slippage (iii) Uprooting of poles and posts (iv) Death of fishes (v) Common damage to buildings (vi) Effects on glaciers (vii) Stopping of pendulum clocks (viii) Snapping of cables.

Transient effects: (i) Perceptible tremors   (ii) Sliche in rivers and ponds (iii) Tsunami (iv) Swaying of bridges (v) Shaking of buildings and disturbance in Birds/animals (vi) Fright and panic among human beings (vii) Hearing of sounds. 

Q: Write briefly about the internal and external factors associated with landslide hazards.

Ans : A landslide is a slow or sudden downhill movement of soil, glacier and rock materials due to the force of gravity. Landslides as erosional processes not only modify the existing topography and landscape, but also cause immense damage to man made structures causing heavy loss of lives arid properties.

(i) Internal factors :

a.     Increase in pore Water pressure

b.     Presence of Kaolinite, anhydric or expansive clays like montmorillonite

c.     Weathering and physico-chemical reactions.

(ii) External factors :

a.     Gravitational force

b.     Prolonged and continuous rainfall

c.     Ground water flow through lapse soils

d.     Wedging action of plants and tree roots e. Tremors due to earthquake-

Q: What are the environmental impacts of drought?

Ans : The problems associated with drouqht can have economic, environmental, and social impacts. Because nature and human society depend on water. Lack of water results the migration of people. It is a very common occurence. The agricultural sector is particularly affected by drought. The lack of water can often cause a decline in crop yields, leading to the reduction in income for farmers and an increase in the market price of products. A prolonged drought, may cause unemployment of farmers and problems for the retailers of agricultural products, having a significant impact on the economy of the area. Health problems like malnutrition, dehydration and spread of various diseases become a common sight in a drought-hit area. Drought can also result in insect

infestations and plant diseases, increasing erosion, habitat and landscape degradation, forest fire, wild fire etc. Prolonged drought like condition leads to desertification.

Q: Describe the causes and effects of Tsunami.

Ans : Causes : The tsunami is caused by earthquakes, volcanic eruptions, explosions under the sea.

Effects: Tsunami has a devastating and catastrophic effect when it becomes a hazard. Tsunami affects the coastal  areas very harshly. The records of the tsunamis that have already taken place point to the destruction of huge number of coconut trees in the coastal areas besides causing a devastating impact on human lives and properties. The hazards of tsunami have taken a heavy toll of human lives. Many people had left their.home and hearth in the tsunami affected areas and being homeless came to live in refugee camps.

Q: Briefly describe the effects of volcanic hazard on the environment.

Ans : Volcanic eruption causes heavy damage to human lives, property and all ecosystems through emitting hot lavas and volcanic materials. Huge volumes of hot and liquid lavas moving at considerably fast speed burry structures, kill people and animals, destroy agricultural farms, forests. These volcanic substances including dusts and ashes, smokes etc, cover the large ground surface and farm lands, forests, men and animals and create acid rains. Volcanic eruption also changes the radiation balance ofthe earth the and atmosphere and thus helps in causing climatic changes. According to some scientists volcanic eruptions cause mass extinction of a few species. Volcanos occuring before and after an earthquake generate destructive tsunamis seismic waves.

Q: How does oil spill affect the wild life?

Ans: The release of liquid petroleum hydrocarbon into the water bodies due to anthropogenic activities is referred to as oil spills which cause severe pollution of the water body and the whole environment as well. These types of incidents are very common in the marine environment.

         Oil spill is mostly caused by sudden accidents or leakage of oil tankers, cleaning of the tankers in shore areas, leakage of oil from the refinery and other fuel industries.

Effects:

a.     Effects on birds: This oil penetrates through the feathers to the body of a bird and impairs the bird's flight abilities, making it difficult or impossible for it to defend itself against predators. This oil also damages, kidneys and the liver function, poisoning the digestive tract. Seals and Dolphins are also affected while feeding on the contaminated species. The reproductive function of the animals is also affected by the oil spill.

b.     Effects on fishes: Fish species are badly affected by this kind of pollution. Oil enters into their bodies through gills, affects the eggs and the larval survival. Reduced growth, enlarged livers, changes in heart and respiration rates, fin erosion, and reproductive impairment are the other adverse effects of oil spills on fishes noticed. Oil has the potential to impact the spawning success, as eggs and larvae of many fish species, including Salmon, are highly sensitive to this toxic substance.

c.     Effects on invertebrates   : Oil can directly affect the invertebrates by altering their metabolic activities.

d.     Effects on plants: Some small, plants, algae, and other aquatic plants are also affected badly. The pollution caused by oil spills can be reduced by some bioremediation and phyto remediation techniques using some bacteria to remove the oils from the water body. Some chemical methods are also used to reduce this pollution.

Q. Write about some events which are called disasters, Why are they called disasters?

Ans: Geological processes, like earthquakes, volcanoes, floods and landladies are normal natural events which have resulted in the formation of the earth that we have today. They are, however, disastrous in their impacts when they affect human settlements. Human societies have withnessed a large number of such natural hazards in different parts of the world and have tried to learn to control these processes, to some extent.

Q. How do earthquakes occur?

Ans : Earthquakes occur due to sudden movements of earth's crust. The earth's crust has several tectonic plates of solid rock which slowly move along their boundaries, ^(hen friction prevents these plates from slipping, stress builds up and results in sudden fractures which can occur along the ' boundaries of the plates in sudden fractures which can occur alongthe boundaries-of the plates or fault lines within the plates. Thiseauses earthquakes, the violent, short-term vibrations in the earth.. The point on a fault at which the first movement occurs during an earthquake is called the epicentre.

Q. How can damages by earthquake be prevented?

Ans : (i) Construction of earthquake-resistant buildings in the earthquake prone zones.

(ii) Weak spots are strategically placed in the buildings that can absorb vibration form the rest of the building, pade or floats are placed beneath the building on which it can shift harmlessly during ground motion.

(iii) Wooden houses are preferred in earthquake prone areas.

UNIT 5: Environmental Pollution

Environmental Pollution

Q. What are the main sources of air pollution?

Ans : (i) Natural sources  (ii) Manmade sources

Q. What are the major air pollutants?

Ans: CO, NO₂, SO₂, VOCs,.suspended particular matter etc.

Q. What are the greenhouse gases?

Ans: These include CH₄, water vapour, carbon dioxide, CFCS etc.

Q. What are the main causes of water pollution?

Ans : Wastes from industries, Excessive heat, Agricultural activities, Domestic wastes

Q. Write two major effects of water pollution?

Ans : (i) Nitrates (more than 90 ppm) from the industrial wastes cause "Blue baby syndrome" disease.

(ii) Hg, As, Pb cause damage to the central nervous system

Q. Write one of the control measures of soil pollution.

Ans : (i) Proper action should be taken before the disposal of domestic wastes, chemical wastes into the soil.

Q. How is noise pollution measured?

Ans: The intensity of sound is measured in sound pressure levels (SPL) and common unit of measurement is decibel, dB

Q. What are the major domestic sources of noise pollution?

Ans : Domestic (movement of utensils, home appliances pressure cooker, television, air cooler, air conditioners etc.

Q. State True of False :

(a)       High temperature causes the quality of the digestive juice.

Ans : True.

(b)       Salmon and Trout fish can lay eggs in high temperature.

Ans : False.

Q. Who is most responsible for environmental pollution?

Ans : Man..

Q. What happened in the USA in 1962-65?

Ans : The USA experienced in severely dry climate-and bitter cold in 1962-65.

Q. What happened in UK during 1961-62?

Ans : The UK experienced drought and erratic climate 1961-62.

Q. What did Russia suffer in 1971?

Ans : Russia suffered extremely low temperature in 1971.

Q. What natural calamity happened in India in 1978?

Ans : India was badly affected by flood in 1978.

Q. When drought badly affected India.

Ans : In 1980, drought badly affected India.

Q. When did the industrial revolution take place?

Ans : Towards the end of 18th century, the industrial revolution took place.

Q. What is abnormal climate?

Ans: When pollution occurs in the environment abnormal changes occur in the climates also. This is called abnormal climate.

Q. Why do floods occur in Assam every year?

Ans : Deforestation and the unplanned construction of embankments are the main causes of floods in Assam.

Q. Describe the atmosphere of Guwahati city.

Ans : The atmosphere of Guwahati is also very much polluted by the smoke, ashes, garbages and population. The motor vehicles and population are mostly responsible for environmental pollution in Guwahati.

Q. What is the full form of SMP?

Ans: the full form of SMP is Suspended Particulate Matter.

Q. When and where did the industrial revolution take place?

Ans: The industrial revolution took place in 18thcentury in Europe.

Q. What is the full form of MIC?

Ans : The full form of MIC is Methyl Isocyanate.

Q. Write the name of the most populous city of India.

Ans : Kolkata is the most populous city of India.

Q. How do the jet planes also pollute the atmosphere?

Ans : The jet planes release aerosol in the upper layer of the atmosphere and pollute the atmosphere.

Q. Which agent is the most responsible for air pollution?

Ans: Motor vehicle is the most responsible for air pollution.

Q. When did the government of India enforce air pollution act?

Ans : The government of India enforced the Air Pollution Act in 1981.

Q. What are the causes of lung cancer and bronchitis?
Ans : The SPM and sulphur-di-oxide are the causes of lung cancer and bronchitis.

Q. Which elements damages our blood circulation system, liver and kidneys?

Ans: Air-born lead damages our blood circulation system, liver and kidneys.

Q. What is personal air pollution?

Ans: When air pollution affects the health of an individual person it is called personal air pollution.

Q. Which elements create acids rain?

Ans : Sulphur oxides and nitrogen oxides create the acid rain.

Q. Write the name of the famous forest of Germany destroyed by acid rain.

Ans : Black forest.

Q. What is the most sophisticated technology to get rid of impurities in water?

Ans : The effluent treatment plant is the sophisticate technology to get rid of impurities in water.

Q. What is the full form of ETP?

Ans : The full form ETP is Effluent Treatment Plant.

Q. What is the full form of DDT.

Ans: The full form of DDT is Dichloro-diphenyl-trichloro-ethane.

Q. Name the worst elements that disturb the ecosystem.

Ans: The destruction of forests and increasing population are the worst elements that disturb the ecosystem.

Q. In which century did the industrial revolution take place?

Ans : Towards the end of 18th century the industrial revolution took place.

Q. What is soil?

Ans : Soil is the upper weathered layer of the upper crust of the earth.

Q. What are the main agents that cause soil erosion?

Ans : Wind and water are the main agents that cause soil erosion.

Q. What are microbes?

Ans: The minute organisms which enrich the soil and make it fertile are called microbes.

Q. What is the cause of alkalinity of land?

Ans: Alkalinity is caused by imbalance use of fertilisers.

Q. What are the precursors of green revolution?

Ans: Fertilisers and pesticides are called the precursors of green revolution.

Q. What is the amount of garbage produced by a man in a day in India.

Ans: Each person produces about 300-600 gm garbage in a day In India.

Q. In what type of land does erosion of soil by wind occur?

Ans: The removal of top soil by violent wind is a common phenomenon to those areas which are dry and devoid of any form of vegetation.

Q. How is salinity of land caused?

Ans: Salinity of land is caused due to frequent irrigation by river water which in its course tends to colfefct salt of various forms from the mountain surface.

Q. What is meant by soil pollution?

Ans : Decrease in the quality of soil either due to anthropogenic sources or natural sources or by both is called soil pollution or soil degradation.

Q. What is frequency?

Ans : The number of vibrations produced per second is called frequency.     

Q. What is the safety range of sound?

Ans: Generally the safety range lies from 30 to 60 decibels.

Q. What kind of sound can our ear detect?

Ans: Our ear can detect the sound from 0 to 180 decibels.

Q. How is the sound created?

Ans : The sound is created by a vibrating body.

Q. What is the average sound of a siren?

Ans : The average sound of a siren is 150 to 160 decibels.

Q. In India, how many people are born deaf, for noise pollution?

Ans: Almost 10 million people are bom deaf, in India in a year, for noise pollution.

Q. What is the average noise level of Delhi?

Ans: The average noise level of Delhi is above 90 decibel.

Q. What is decibel and its use?

Ans : The unit of the intensity of sound is called decibel. The degree of noise is determined by this unit.

Q. Generally what type of sounds pollute the environment?

Ans : The sound from industries, factories, heavy diesel vehicles, motor bikes, .whistles of train and vehicles, diwali crackers etc. pollute the environment.

Q. How many people lose their hearing power every year in Sweden?

Ans: In Sweden every year almost 16,000 people lose their hearing power due to noise pollution.

Q. What is Radiation?

Ans : All the electromagnetic waves are called radiation.

Q. Which electromagnetic wave is very harmful for us?

Ans : Gamma electromagnetic wave is very harmful for us.

Q. Which electromagnetic wave has no charge?

Ans : Gamma electromagnetic wave has no charge.

Q. What is an electron?

Ans : An electron is a very small particle with negative charge and it is found in all atoms.

Q. Why Uranium, Thorium and Plutonium are used to produce nuclear energy and weapon.

Ans: Uranium, Thorium and Plutonium are heavy elements and they are radioactive in nature.

Q. What is called 'natural selection'?

Aas : The abnormalities are eliminated in plants by the evolutionary process called, 'natural selection'.

Q. What is 'nuclear winter'?

Ans : Nuclear explosion may cause a peculiar situation. The scientists call this peculiar situation, 'nuclear winter'.

Q. What is radioactivity?

Ans: Radioactivity is the spontaneous emission of powerful radiations fiom some substances without any energy being supplied from outside.

Q. 'The Discovery of nuclear weapon is very dangerous for mankind’. Explain.

Ans : The nuclear weapons destroy our present and the radioactive radiations of nuclear weapons destroy our future. That is why nuclear weapon is very dangerous for us.

Q. What are the air polluting substances released in India?  

Ans : Sulphur-dioxide, carbon-dioxide, hydrocarbons, hydrogen sulphide, SMP and lead particles are the polluting substances released in India.

Q. What is 'smog'?

Ans : Nitrogen oxides and hydrocarbons form a layer at high temperature in our atmosphere, it is called smog. It is a grey or yellowish brown opaque substance deposited in air.

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Short notes:

(a)Tropical region: Equator divides our earth into northern and southern hemispheres. The nearby areas of the equator on both sides are under the Tropical region. For the climatic changes the| tropical regions are badly affected. The countries of the tropical region now face many problems. But the floods and droughts are the major problems for them.

(b) Polar regions: Our earth has two poles - north pole and south pole. These are called Polar Regions. The Polar Regions are called water reservoirs, because the Polar Regions are always covered with thick ice. At present the scientists are concerned about the global warming. If the global warming increases, the ice of the Polar Regions will melt, and floods will occur almost all over the world.

(c) The Himalayas : Himalayas are the highest mountain range of the world. It is also water, reservoir, because many parts of the Himalayas are covered with thick ice. Many big rivers of India come out from the Himalayas. So if the global warming increases, the Himalayas will supply more water to the river, and floods will occur in many places.

(d) Aerosol: Aerosol is fine solid or liquid particles in the atmosphere which exert a lot of influence on the other gases including sulphur-dioxide. It exists in air in the form of smoke, fog and vapour. It is very harmful for our atmosphere.

(e) Fossil fuel: The remains of organisms embedded in the surface of the earth, contain high carbon and hydrogen. Those elements are used by man as fuel. This kind of fuel is called fossil fuel.

(f) Minamata disease : The water polluted with mercury may causes many a disease. One such disease occurred first in the Bay of Minamata in Japan. So this disease is called Minamata disease.

(g) Mercury : Mercury is a poisonous substance. Use of mercury has been increasing rapidly as it is required especially in paper mills and electrical industries. Some other industries also use mercury. Now the production rate of Mercury in me world is about 9,000 tons per year. The water polluted with mercury may cause many diseases in aquatic and other animals.

(h) Household-waste : Cowdung, carcasses of cattle, dogs, cats, goats and other animals, excreta of various animals, lumps of straw and hay, various types of vegetable wastes, litters etc. are called house-hold wastes. These house-hold wastes also pollute the water.

Q. Describe the reasons of changes in weather and climate?

Ans : There are many natural and man-made reasons of changes in weather and climate. But men are more responsible than the nature. The burning of fossil fuels, the rapid population growth, destruction of forest etc. are the main factors of environment pollution. These are the main reasons of changes in weather and climate.

Q.  Describe what happened to the climate of the world during the second half of the hat century.

Am: During the second half of the last century, we found many changes in climate. In 1962-65, the USA had the experience of a severely dry climate and bitter cold, in 250 years. The UK had the experience of the coldest climate in 1961-62. Europe also suffered drought in 1976. Russia suffered the extremely low temperature in 1971.

Q. How do the changes in climate affect the people in the developing counties?

Ans: The developing countries are generally located in me monsoon regions. For the climatic changes me monsoon shows the erratic behaviour in these regions. As a result, heavy floods or drought occur. In the developing countries most people depend on agriculture. If the floods or drought occur every year, that means heavy damaged to the crops. The irregularity of monsoon also affects the crops and the life of the people. In this way the climatic changes affect the people in the developing countries.

Q. What did happen to the Brahmaputra and Barak valleys in the second half of the last century?

Ans : Since the second half of the last century, there have been heavy floods in the Braghmaputra and Barak valleys of Assam. Severe drought conditions also occurred. So the floods and drought are perennial problems of Assam. For the climatic changes, the south-west monsoons are very irregular in these regions and there is scanty of rain.

Q. Discuss the abnormal climatic conditions of the world.

Ans: For the natural and mad-made factors some abnormal behaviour has been observed in nature, hi 1962-65, the USA had the experience of a severely dry climate and bitter cold. The UK had experienced the coldest climate in I961-62. Drought and erratic climate were the main features of Europe in 1976. Russia had experienced the extremely low temperature in 1971. Destruction of forests and tropical rah, forest are the causes of abnormal climate.

Q. Discuss the main causes of climatic changes.

Ans : For climatic changes both the nature and man are responsible. But man are more responsible than the nature. The rapid growth of population, deforestation, excessive use of natural resources, burning of fossil fuels, increasing industries are me man causes of climatic changes

Q. Why do floods occurs in Assam so often.

Ans:In Assam the rainfall is decreasing and even then the floods occur every year. Deforestation and unplanned construction of embankments are the main causes behind the rise of river-beds and consequently floods occur frequently.

Q. How do the developing countries hamper the ecosystem? Discuss.

Ans: The rate of population growth is higher in developing countries than the developed countries. People pollute me air and destroy the forests for more cultivable lands. The rapid increase of population also hampers the progress of the developing countries and leads to poverty and undue interference on the activities of the ecosystem. In this way the developing countries hamper the ecosystem.

Q. Discuss, how the climatic changes, hamper the progress of the developing counties?

Ans: Generally the developing countries are located in the monsoon regions. The monsoons greatly influence the lives of the people. Most of the people depend on agriculture and agriculture depends on monsoon.

But for the climatic changes, the monsoon shows an erratic behaviour in those regions. As a result every year floods or droughts take place in those regions and hamper the crops. The monsoons come sometimes early, sometime late and sometimes they show uncertain behaviour. In this way the climatic changes hamper the progress of the developing countries.

Q. ‘Urban areas are most responsible for environmental pollution'. Discuss

Ans : The industries, factories etc. are mostly established in city or towns. The industries, factories etc. burn the fossil fuels and release a large amount of smokes and ashes to our environment. There are plenty of motor vehicles which burn the petrol, diesel etc and produce a plenty of smoke and ashes and pollute the atmosphere. The urban areas generally provide more opportunities for earning livelihood. So the people come to the towns or cities. The people also pollute the air. In some cities or towns many forests are also destroyed for their own projects. For these reasons urban areas are responsible of environmental pollution.

Q. What is 'Green House Effect'? Discuss.

Ans: Industries, factories and motor vehicles burn the fossil fuels and pollute our atmosphere. The polluted air contains carbon-di-oxide, carbon monoxide, methane, lead, aerosol etc. These elements allow the sun rays to fall on earth and on the other hand traps the outgoing radiation from the earth. In this way these elements help to increase global warming. This phenomenon is called 'Green House Effect.'

Q. What is air pollution? What are its categories?

Ans : The presence of pollutants in air which is the cause of injury and damage to human beings, animals, plants and other objects is called air pollution. Air pollution is of three categories. These are - personal, occupational and community air pollution.

Q. 'Nature also pollutes air' - Explain. Ans: Air pollution is also caused by nature itself. It may be due to respiration from man and animals, dusts, bacteria, fungi, pollens, spores, volcanic gases etc. So it is said, 'nature also pollutes air'.

Q. Describe the extent of air pollution in some major cities of the world.

Ans : The air of some industrial cities are always covered with smog. An aerial view of the cities like London, Tokyo, New York etc. shows that these cities are covered with thick smog. Excessive burns of petrol, diesel, coal etc. produce the harmful gases like carbon-di-oxide, nitrogen oxide and sulphur-dioxide and they pollute the air. The rapid urbanisation, deforestation, land erosion are also the causes of air pollution.

Q. Can air pollution be rooted out entirely? How can it be controlled?

Ans : No, the air pollution cannot be rooted out entirely. The air pollution can be controlled as follows :

·   We should reduce burning fossil fuels and think for alternative fuels.

·   We should change our old technology and industrial equipments.

·   The government should strictly enforce the law of Pollution.

·   We should use purified fuel in our motor vehicles.

·   Plantation of trees is also a good method to control air Pollution.

Q. Describe the legal and organisational aspects of controlling air pollution.

Ans : The government of India .has enacted a law in 1981 to control and prevent the air pollution. This act is implemented by central pollution control board and state pollution control boards. Thus government organisations are now handling the law of pollution to control air pollution.

Q. What is the best way to minimise air pollution?

Ans : The best way to minimise air pollution is to replace the old technology and the equipments of industries, factories; motor vehicles etc. and think for new anti-pollution devices.

Q. Discuss the major causes of air pollution.

Ans : The major causes of air pollution are :

a. We burn excessive fossil fuels in industries, factories and motor vehicles and produce a huge amount of harmful gases and smoke and pollute the air.

b. The rapid growth of population pollute the air.

c. The rapid urbanisation, deforestation, land erosion etc. also pollute the air.

Q. What are the sources of water pollution?

Ans : There are many sources which are responsible for water pollution. Among them eroded soils, decomposed body of plants and animals, fallen leaves, organic materials, chemical fertilizers, industrial wastes, municipal and house-hold wastes are the main sources of water pollution.

Q. How does mercury pollute water?

Ans : Some industries use mercury compounds. Mercury has been increasing through paper mills and electronical industries. When this poisonous compound mixes with-water, it causes many diseases in our body. In this way the mercury pollutes water.

Q. How do ships carried crude oil pollute the sea water?

Ans : When crude oil is carried by ships across seas and oceans, some crude oil spills to the seas owing to leakage and other reasons. This spilt crude oil spreads over wide area forming a scum. Crude oil neither dissolves in water nor evaporates. It remains in water for a very time and pollute die sea water which is very harmful for marine lives.

Q. How did mercuric compound cause Minamata disease?

Ans : The industries dumped mercury compound on the shore of the Minamata Bay of Japan. This poisonous compound pollutes the water. Fish were affected by the polluted water and the inhabitants of Minamata Bay consumed those fishes as food and tftis disease occurred there. In this way the mercuric compound caused Minamata disease.

Q. Describe how seas and oceans are polluted?

Ans : The polluted water of towns, cities and agricultural fields flows through the rivers and their tributaries to seas and pollute the sea water.

The crude oil spreads in seas and oceans through the leakage of huge oil tankers carrying oil. This crude oil is neither dissolved in water nor evaporated. It remains in water for a long time and pollutes the water and affects the marine lives.

Q. Explain how the water drawn from wells may be harmful?

Ans : The rivers and their tributaries carry the poisonous substances to the sea. These substances may go down the earth's crust and pollute the underground water, which we use for our drinking. So the water drawn from wells may also be harmful for our health.

Q. How are the aquatic lives affected by pollution?

Ans : The nutrients in the lakes, river, seas etc. help algae and weeds to grow under water luxuriantly. They consume large amount of oxygen and exhaust the stock of oxygen and create a dearth of oxygen in sea water which, greatly hamper the aquatic lives. In this way the aquatic lives are affected by pollution.

Q. What is environment?

Ans: Environment means surrounding; we are surrounded by abiotic and biotic factors of environment. The various types of radiation, air, water, rocks etc., form the abiotic environment. Living organisms that interact among themselves form the biotic environment.

Q. What does environment sciences provide us with?

Ans: Environment science provides us with an approach towards Understanding the environment of our planet. It also tells us about the impact of life on it and vice-versa. It also makes us to enquire for the solutions to environmental problems that confront mankind now.

Q. What special position does the earth enjoy in the solar system?

Ans : The special position of the earth in the solar system is that it is the only planet that supports life. The environment of the earth is conducive for the existence, growth and development of livingbeings.

Q. What is solar system? How many planets are there in it? While is the planet that supports life?

Ans: The sun and its family of nine planets along with their satellites is the solar system. There are nine planets in it. The earth is the only planet that supports life.

Q. How does environment affect life on earth?

Ans: Environment affects the size, shape and colour of plants animals and the ways in which they grow and live. Environment is responsible for survival of any particular organism. We get food, clothing and other things necessary for our survival from environment.

Q. Mention some of the uses of water?

Ans : Water is essential for sustaining life. Water is also used for bathing, washing cleaning, irrigating crop lands, generating electric powers, running factories and for many other service.

Q. Write briefly about Hydrosphere?

Ans : Hydrosphere includes all water bodies on earth. The oceans, seas, rivers, ponds etc. are all parts of it. Oceans and seas cover 71 % of the hydrosphere. Only 0.04% is frets water usable by man and other animals. Water is not as scarce as petroleum oil and coal because it is reusable.

Q. Why is water not like coal or petroleum oil? Or, How is water different from coal and oil?

Ans : Coal and petroleum oil exhaust for ever once they are used. They cannot be savvied or recycled once they are burnt on the other hand water remains more or less at the same level due to water cycle prevailing on earth.

Q. Write a short note on Lithosphere?

Ans : Lithosphere is the hard surface of the earth which accounts for 29% of the total surface area on the globe. It is the crust of the earth and it is made up of old a 'ks and minerals mixed up with various substances. It provide, habitat to all kinds pf plants, animals and microorganism. Lithosphere holds human civilization and all the man has made.

Q. What are the divisions of our environment?

Ans : On the basis of its physical characteristics our environment is divided into:

a.     Lithosphere (land or soil)

b.     Hydrosphere (water bodies)

c.     Atmosphere (air)

d.     Biosphere (Plants and animals)

Q. What is the importance of air?

Ans : Air is essential for all living beings in the biosphere. Man cannot live even for few seconds without air. He breathes 22000 times a day and inhales 16 Kg. of air from the atmosphere. Air is the store house of oxygen for man and other living beings and of carbon dioxide for trees and plants without air there will be no rain, cloud, and snow, fog etc.

Q. How would you explain water cycle?

Ans: Watermoves in the atmosphere in cyclic order. Water cycle begins with the evaporation of oceans, seas, rivers, lakes and all other water bodies. Evaporation occurs due to sun heat The vapour forms cloud in the sky and then comes down to earth in the form of raindrops, hail stones, dewdrops and snowfall etc.

Q. What is atmosphere and why is it necessary?

Ans : The gaseous cover that surrounds the earth on all sides and controls life on it is called atmosphere. It protects earth's surface from becoming too hot. It filters the solar radiations and prevents the harmful ultra violet rays from reaching the earth's surface.

Q. What are the main sources of air pollution?

Ans : Air pollution occurs when pollutants are released into air. The main air pollutants are automobile exhaust, industrial smoke, solvent and radioactive radiation and particulates.

Q. What is smog? What harm does it do?

Ans : The word smog has been formed of smoke and fog. Smog IS a thick layer of Smokey fog that floats over cities. Smog has occurred over London, Glasgow, Delhi, Chennai, Kolkata. About 3.500 to 4000 people had died in the London smog of 1952. Smog causes respiratory trouble leading to slow but painful death.

Q. Write a short note on solvents?

Ans : Solvents are used in paints, polish and sprays. The use of paint, polish etc has been increasing. Accordingly the use of solvent too is increasing steadily. The spray materials remain suspended in air for a long time and are very harmful to man. Pesticides and insecticides contain solvent. They pollute air in rural areas.

Q. What are particulates and what do they do?

Ans : Particulates are commonly Known as SPM (Suspended Particulate Matter). They consist of both solid and liquid tiny particles. They include dust, mist, spray, smoke, fumes etc. Normally chimneys in factories and power plants pour them out. Particulates create respiratory problem in, human beings.

Q. What is ozone layer? What is its function?

Ans : Ozone layer is a gaseous layer in the atmosphere. It exists about 10 to 60 km above the surface of the earth. It is like an umbrella that protects the living beings and plants from the dangerous and harmful Ultra Violet Rays.

49. Who detected the ozone a hole? What coured it?

Ans : A British Antarctic Survey Team reported 40% loss in ozone layer. They detected it in 1985. Scientists after study found that the new threat, the hole in the ozone layer was caused by a chemical called CFC (Chloro Fluoro Carbon), which is used in modem personal care products, and Refrigerators.

50.    Write a note on Greenhouse and its usefulness.

Ans : Green house is made of glass. It is used for growing

plants. During winter season in the cold countries the insulation is not sufficient for plant growth. The green house allows visible sunrays to enter into it, but prevent the infrared rays to go out. Thus gradual warming up takes place inside the green house favouring growth of the plants.

51.    What green house effect?

Ans: The green house effect means a progressive warming up of the earth's surface due to blanketing effect of man made corbon dioxide and some other gases in the atmosphere, with the increasing accumulation of carbon dioxide in the atmosphere global temperature will increase gradually.

52.    What will be the effect of global warming?

Ans : If temperature riser gradually as a result of global warming the glaciers will melt, the level of the water bodies like sea and ocean will rise and many low lying areas will be submerged. The marine ecosystem will be damaged affecting all aquatic life.

53.    What is acid rain? What causes it?

Ans: When rain water contains acid, it is called acid rain. Pollutants like oxide of sulphur, nitrogen an carbon remain accumulated in the atmosphere. Rain water dissolve them and transforms them into weak acids and the drops finally come down to earth in the fortify of acid rain. Amount of acidity depends on the accumulation of the gases mentioned above.

Q. What are the effects of acid rain?

Ans : Acid rains are the main cause of deaths of lakes for which it is called lake killers. Acid rain kills aquatic lives including plants and animals. It destroys the mineral elements and other nutrients of soil and adversely affects production. It also affects human beings and building etc. and other structures.

Q. What are the major water pollutants?

Ans: When water becomes unfit for drinking or supporting life due to degradation of its quality it is called polluted. Industrial wastes, home sewage, run off from mining area or crop field, hot water from power plants, oil and radioactive wastes are the major water pollutants.

Q. Show how oil pollutes water?

Ans:. Oil tankers sailing in sea, sometimes develop leakage or sometimes they meet with accidents. As a result oil flows down to the surface of the sea water off. Shore drilling also releases some amount of oil into sea water. The oil spreading in sea water affects birds other aquatic life. Feathers of aquatic birds are socked in oil and they die soon.

Q. How does power plants pollute water?

Ans : Fresh water flow is needed in power plants. Water-cools down the steam condensers. After cooling the condensers the hot water is released into water bodies, which changes the temperature of the water. This is called thermal pollution. Changes in temperature of water can harm fish population. 58. Write a note an earth's environment. Ans : 'Environment' means surrounding. We remain surrounded by various types of radiations, air, water, soil rocks and minerals which forrrUhe abiotic factors of the environment. We live interacting with them similarly we remain surrounded by biotic environment consisting of living organisms. We live reacting with them and we are inter related with them. Environment affects size, shape and colour of plants and animals. The environment may also be responsible for survival of S9me certain organisms. We get our food, clothing and shelter from our environment. Man also lives in a cultural environment. He lives surrounded by things he has made. Among the nine planets in the solar system only the earth has an environment that can life. It is earth's environment that has made the existence, growth and development of living beings. Based on its physical characteristics of earth's environment are divided into: Lithosphere, Hydrosphere, Atmosphere and Biosphere. Biosphere supports life and it is related to other three spheres.

Q. Write a note on Hydrosphere.

Ans : Hydrosphere is the water bodies an earth, 71 % of one planet is covered by the oceans and seas 96.5% of the total water on earth is found in the seas and oceans, 1.76% of the total water is there in the ice caps and glaciers. 1.70% is the ground water. Only the balance 0.04% is fresh water. Freshwa ter is found in the rivers, lakes and streams. Fresh water is not abundant. Still we do not feel scarcity of water. Because water is not exhaustible source like coal or petroleum oil. Water cycle on earth keepsthe water level almost steady. Water cycle, begins with evaporation of sea and ocean water under the heat of sun. The vapour sails in the sky in the form of cloud and then comes down to earth as raindrops, dew, fog or snow. Water is an essential life-supporting element on earth. Besides drinking, water is used for bathing, cleaning, irrigating, and generating electric power and so on. Much ancient civilization flourished on riverbanks mainly because of the water streams.

Q. Write a note on atmosphere.

Ans : The atmosphere is a gaseous cover surrounding the earth. It preserves life on earth. The atmosphere protects life on earth by way of filtering the sunrays. It prevents the harmful ultra violet rays of the sun from coming to earth's surface. Air is essential for all types of life in the biosphere. Man cannot survive even for few seconds without air. A man breathes 22000 times a day inhaling 16 kg of air from atmosphere. Oxygen in the air is essential for man and animals while carbon dioxide is essential for trees and plants. Air is the reservoir of both oxygen and carbon die oxide and many other gases. Without air there will be no wind, clouds, fire and rain on earth. Air is a mechanical mixture of several gases. It contains 78.084% nitrogen, 20.95% oxygen, 0.93% argon and 0.03% carbon dioxide.

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Q. Write a note on environmental degradation.

Ans: Thousands of years ago the primitive men depended on nature for his food, drinks and shelter. They hunted in' forests, fished in water and ate wild fruit and thus satisfied their simple needs. Population grow more and society developed, man changed the natural habitat to villages, towns and cities, railways, highways, factories and industries were established with this change from started the process of environment pollution or degradation. Not only man natural forces also pollute environment. Earthquake, volcanic eruptions, land-slide, floods. etc degrades environment. Nature has her own system of recovering minor environment degradation. When exploitation of Nature by man is unlimited nature fails to recover. The earth has been facing serious environmental problems during the previous three decades. Increase in population, spurt in technology aided by mans greed to get more and more things have polluted air, water and soil. The atmosphere is so much polluted now that it has paused a threat to mankind and other living beings. Unless something is done urgently environmental degradation may endanger all life on earth.

Q. Mention some of the measures to be adopted for controlling air pollution.

Ans: The following measures should be adopted for controlling air pollution.

a.   The engines of the automobiles should be redesigned the emissions at minimum level.

b.   Steps should be taken for (i) regular servicing of the vehicles, (ii) use of filters, (iii) replacement of old engines and parts by new one. (iv) proper tuning-ups of the engines should be done.

c.   Industries should be located at a safe distance from the residential areas.

d.   Traditional use of fire-wood, coal etc. should be minimized and smoke-free devices should be used. Forest fires also should be 'Checked,

e.   Without implementation of pollution control system, industries'should not be accorded permission for production.

f.    There should be greenbelt around towns, townships and villages. Also there should be green belt around industries.

g.   Railways should use electric engines instead of coal or steam engines.

h.   There should be strict provision of law regarding pollution control in case of automobiles and industries.

Q. What is water pollution? Suggest some of the measures for controlling water pollution.

Ans: When water becomes unfit for drinking or supporting life due to degradation of its quality. It is said to be pollution. The industrial wastes, home-sewage, run-off from mining area or crop fields, hot water from power plants, oil and radioactive Wastes are the major water pollutants.

Following measures are to be adopted for controlling water pollution:

a.       There should be strict regulations by Government to the effect that no industry can release industrial wastes into rivers or streams without proper treatment in the effluent treatment plant. Production should not be permitted without the establishment of the treatment plant.

b.       Domestic and other sewage should be treated in sewage treatment plant, and only after such a treatment it should be allowed to be discharged into water bodies.

c.       Use of chemical pesticides and fertilizers should be limited and only herbal pesticides should be used.

d.       There should be complete ban an disposal of dead bodies of man and animals into rivers. River banks should be kept clean.

e.       Aquatic plants should be cleared at short intervals.

f.        Water should be kept purified from harmful micro organisms by using potassium permanganate.

g.       Above all people should be made aware about the harmful effect of water pollution. So that they learn to protect themselves from water borne diseases.

Q. Suggest some measures to control of soil pollution.

Ans : The following measures may be adopted for control of soil pollution :

·         Municipal and industrial wastes should not be dumped he~ and there on the soil.

·         There are various methods of treating the wastes. The treatment of water should be undertaken in such a manner that it should be economically viable and does riot give rise to new problems. Composting is the best way for solid wastes treatment. It is a good way to recycle the resources in the solid wastes and it also makes the soil fertile.

Some new methods of waste disposal planned and devised in some countries of the World are listed below:

·         The organic part of the wastes are to be transformed into sugar or proteins.

·         The organic refuse, may be converted into useful gas like methane.

·         In developed countries, the wastes are burnt in a specially designed furnace. The heat is used to boil water, which in turn produces steam which can be used in Industries..

·         Use of degradable plastic bags instead of non-degradable plastic bags.

·         To plant more and more trees to resist soil loss by erosion.

·         People in general are made aware of the evil effects of pollution and they are involved in programmers meant for the protection of the environment.

Q. Write a note on Greenhouse effect.

Ans : Greenhouse is used for plant-growing in cold countries. During winter season in the cold countries the insulation is not sufficient for plant growth. The Greenhouse, made up of glass, allows visible sunlight to enter into it but prevents the infrared rays to go out. Thus a gradual wanning up occurs inside it favoring the growth of the plants. The 'Green house effect' means a progressive wanning up of the earth's surface due to blanketing effect of man made carbon dioxide and some other gases in the atmosphere.

As the amount of carbon dioxide in the atmosphere is increasing day by Jay, Scientists say that the global temperature will increase gradually. If the temperature rises gradually, the glaciers will start melting, the level of the water bodies like Sea and Ocean will rise and many low lying areas will be submerged. The marine ecosystem will be damaged. So, global warmingis mainly due to increasing Co2 level in the atmosphere. Industrialization, deforestation and increasing number of fossil-fueled vehicles on the roads are the principal sources of Co2 increase. Steps should be taken to minimize the emission of Co2.

Q. What is the definition of pollution and write briefly about its different types.

Ans : The term pollution have derived from latin word pollute. Pollute means make dirty. Thus pollution means a change in the phisycal, chemical and biological aspects of environment. This pollution is very harmful to human life and all other living bengs. There are different types of pollution. These are as follows:

(a) Air pollution: Air is polluted when ar pollutants are released into the air. Air pollution affects not only human beings, but,also plants, crops and building etc. Mainly automobile exhausts pollute air. The automobiles and industries release the pollutants called Sulfer oxides, Nitrogen oxides, Hydrocarbons, carbon monoxide and particulates.

(b) Water pollution: Water is called polluted when it becomes unfit for drinking or supporting life, pollution degrades water. Industrial wastes, home sewage, hot water released by power plants and radioactive wastes are the main pollutants of water. Pollutants bring in adverse change in physical, chemical and biological properties of water. Water pollutants are found in three states. The suspended pollutants remain floating on water. Dust" mineral, foam, clothes, paper etc are suspended pollutants. The colloidal pollutants remain mixed up with water. They are not easily separable. The third type of pollutants remains dissolved in water. Gasses and minerals belong to this type of water pollutants. Water pollution may be due to natural canses or it may be man made.

(c) Radiocative pollution: Radioactive materials pollute atmosphere. They are released into air by nuclear weapon testing establishments, nuclear reactors, chemical processing plants, hospitals and research institutes. They release radio nuclides to the atmosphere, which are really injurious to health. Radioactivity related activities have, been increasing all over the world making a serious threat to mankind in future. Explosion of atom bombs in Nagasaki and Hiroshima in Japan during the Second World War have done great damage. In spite of its destructive nature nations have been performing nuclear tests. The radioactive particles remain suspended in, air and finally settle down on soil or water. Thus radioactive pollutants pollute air, water and soil as well. Leakage in nuclear reactors also pollute atmosphere and killed many people in Russia. Radioactive pollutants can cause skin disease, cancer, respiratory problems, abnormal births and many more problems.

(d) Soil pollution: Domestic and public wastes, industrial and mining wastes, agricultural wastes, radioactive materials and biological agents are treaded as soil pollutants. Pollution degrades soil and changes its physical, chemical and biological properties; pollution also degrades productivity of soil. Household garbage such as newspapers, plastic, bottle etc., are heaped here and there. These heaps are the breeding and growing grounds of germs. These dirty tilings help in spreading typhoid, dysentery, plague etc. Industrial wastes are carried away by rainwater,"enter into earth's surface and pollute ground water. They also pollute atmosphere and cause serious public health problems. Modern agricultural system is also polluted soil by way of using fertilizers and chemicals etc. In the same manner radioactive materials and biological gents like the parasites also pollute soil.

5. Noise pollution: Noise has been defined as unwanted and unpleasant sound that causer displeasure to man. Noise causes deafness; sleep lessens, stress and anxiety. It also affects blood pressure and the working of the heart. The idea of noise differ from man to man, some people can bear loud noise while others cannot. The unit of measuring noise is decibel. In the industrial areas in the Indian cities the range of noise pollution is between 75r90 dB. It is louder in aerodromes, railway stations and bus terminuses. Noise pollution is primarily made by the industries.

AIR POLLUTION

Q. What do you mean by air pollution?

Ans : Air is a mixture of many gases and moisture with some inert materials. When the quality of the air changes due to presence of other materials in such concentration as is harmful to men and their environment then it is called air pollution.

Q. What are the gaseous components of normal air?

Ans : Gaseous components of normal air are- Oxygen= 20.9%  Nitrogen= 79%  Carbon-dioxide= 0.03% and a few other gases are also present in trace amounts.

Q. What do yhou mean by pollutions? What are the different types of pollutions?

Ans: Any solid, liquid or gaseous substance present in such concenrtration as may be injurious to the environment is called pollutant. Any substance which causes pollution is known as pollutant.

There are two types of pollutants —

(i) Biodegradable pollutants, which are degraded quickly by biological process, like domestic wastes.

(ii) Non degradable pollutants, which either donot degrade or degrade very slowly, like heavy metals and toxic, trace elements.

Q. What are the material sources of air pollution?

Ans: (i) Carbon monoxide: It is released by automobiles and by factories where coal is used as fuel. Excess carbon monoxide in the atmosphere causes serious complication in man affecting nerve, heart and lungs.

(ii) Sulphur compounds : There are released due to biological decomposition, volcanic eruption and from factories using coal and petroleum. Smelting of sulphur areas also release 'sulptiur dioxide. Sulphur dioxide particularly causes respiratory ailment, headache, eye irritation etc. S0₂ reacts with rain water and forms acid rain which harm plants as well as buildings.

(iii) Nitrogen Oxide : Its main sources are automobile exhaust, power, generator, anaerobic decomposition of organic waste. It causes eye and nose irritation and pulmonary discomfort.

(iv) Hydrocarbons : Its important sources are automobile exhaust, incomplete combustion of fuel, explosives etc. It causes irritation of eye and mucous membrane, lung cancer etc.

(v) Photochemical : Certain pollutants mix with other pollutants under the influence of UV radiation and form some compounds, such as peroxyacetyl nitrate (PAN) Ozone (O) and particulates all forming photochemical smog. PAN and ozone cause many complication in man like irritation of eye, caughing headache etc. Ozone also seriously impairs plant growth.

(vi) Smoking: Tobacco smoking is closed chambers, buses and trains affects others. Tobacco smoking causes thickening of epithelial layer and forms precursors of cancerous cells.

Q. What are the particle sources of air pollution?

Ans : (i) Lead : Automobile exhaust is the main source of lead pollution. Lead pollution is also caused from painting, ceramics, pesticides etc. Over exposure to lead interfere with the development of RBC, disrupt functioning of cells, circulatory and nervous system.

(ii) Cement and other dust : Oment particles affect plant growth in that the leaves fall prematured and produce infertile seeds. Domestic and agriculture dust, pollen grains, microbial spores cause allergy and other con plications in man.

(iii) Fluorides, salts and agricultural chemicals : Fluoride when released in excess settles down on vegetation. It causes toxic effect on animals and calcifies theu bones and teeth. Potassium salts and sodium chloride also affect plants in various ways. Pesticides and herbicides released from factories greatly affect men' and animals.

Q.    What is photochemical smog?

Ans : Photochemical smog is formed when hydrocarbon and nitrogen oxide mix with other pollutants and free radicles of oxygen. Nitrogen dioxide impart the brownish colour to the smog. These chemicals mainly arise from fumes and exhaust of motor vehicles. The complicated reaction that involves in smog formation is induced by the sunlight and contains such substances as peroxides, aldehydes, ketones, sulphur and contains such substances as peroxides, aldehydes, ketones, sulphur trioxide, some metal particles. Photochemical smog is a serious phenomenon of gigantic industrial cities.

Q. What is ozone layer depletion?

Ans : A thin ozone layer of the stratosphere acts as shield from harmful effect of ultraviolet radiation.Ozone layer has already become .thinner due to release of various chemicals into the atmosphere by industries. The most damaging chemicals recognised today are chlorofluerocarbon compounds used as aerosol propellants and refrigerants. Considerable thinning of ozone layer has been recorded in USA and UK Thinning of ozone layer will seriously affect agriculture, climate and human health.

Q. What are the major industries that cause air pollution?

Ans: The major industries which cause air pollution are –

a.     Automobile, such as cars, scooters, locomotives etc.

b.     Industrial processors, such as chemical plants, paper mills, cement factories, petroleum refineries, cotton mills rubber factories, plastic factories etc.

c.     Heating plants, such as thermal power plant, atomic power station, domestic burning of coal etc.

Q. What is green house effect?

Ans : Continuous burning of fossil fuel and deforestation change gas balance of the atmosphere, particularly C0₂ with respect to other gases. It has been estimatted that over the past century, CO, has increased by 15 percent in the atmosphere. As a result of this, temperature of the earth is increased causing an effect called green house effect The earth is hearted by the sum. The heat is radiated back by earth. The CO around the earth forms an envelope which allows the light to pass but absorb the heat in the infra-red wavelength. As a result of this, the air around the earth becomes warm. The warm air reradiate heat back to earth.

Q. What is albedo effect?

Ans: Contrary to the green house effect, another effect called albedo effect has also been noticed, this is cause by addition of solid particles and droples into the atmosphere. These substances reduce the sunlight reaching the earth and thereby tend to lower the temperature of the earth.

Q. Write about the effect of air pollution on man and animals.

Ans: Air pollution affects man as veil as animals. Some of the bad effects are—

a.     Sulphur dioxide causes respiratory ailment, headache, eye irritation, irritation of mucus membrane tausing dryness of mouth and throat.

b.     Hydrocarbons affect mucus membrane, jronchial tract, lungs, They may cause lung cancer.

c.     Photochemical smog causes severe complications like coughing, headache, pulmonary congestion.

d.     Oxides of carbon, nitrogen, sulphur often diffuse into the blood stream and combine with haemoglobin causing reduction in oxygen transport capacity of the blood.

e.     Pollen grains and fungal sportes cause allergy. Dust and cotton fibres cause pulmonary troubles and asthma. Mine dust causes black lung disease. Smoke affects lung.

f.      Lead pollution affects RBC, circulation of blood and nerves.

g.     Fluoride, particularly affects grazing animals as it causes toxicity in animals which lead to loss of weight, frequent diarrhoea etc.

Q. Write about the effect of air pollution on plants.

Ans: Effect of air pollution on plants are as follows

a.     Sulphur dioxide, fluorides, hydrocarbon are mainly

b.     Responsible for damage of chlorophyll with reduced plant growth.

c.     Decay of plant tissues or necrosis is caused by fluorides, sulphur dioxide, photochemical smog etc.

d.     Leaf fall, bud fall and discolouration of flowers are caused by hydrocarbons.

e.     Oxides of nitrogen and fluoride pollution leads to stunted growth, development of small fruits.

Q. What are the methods of controlling air pollution?

Ans: Methods of controlling air pollution are as follows-

a.     Use of settling chambers, bag filter, electrostatic

b.     Precipitator, gas absorber, catalytic combustion agents etc.

c.     Chimneys should be raised so tht smoke and particulate matters are thrown high and are carried by wind for dispersal.

d.     Recycling of harmful chemicals and their reuse.

e.     Control over use of fuel.

f.      Exhaust emission by automobiles must be reduced by mechanical means.

g.     Generally, industrial activities should be located away from residential localities.

h.     Plants which can reduce the toxicity and can absorb pollutants should be cultivated in great number.

WATER POLLUTION

Q. What do you mean by water pollution?

Ans : When water contains substances more than it is wanted or it contains harmful elements, germs or particles, then the water is called polluted water. The physical and chemical properties of such water is substantially different from pure water. The degree of difference, indicates the degree of pollution.

Q. What are the sources of water pollution ?

Ans : (i) Sewage : Organic and inorganic wastes are regularly discharged by humans into rivers, lakes, seas etc. The sewage includes biodegradable waste and minerals, such as nitrates and phosphate of detergents, sodium, calcium, chloride ions etc. Mixing of detergents'and other chemicals prevent proper biodegradation process and due to daily addjtionj of newer quantities, the wastes get accumulated.

(ii) Agricultural Pollution: Inorganic fertilizer, pesticides, herbicides used in crop field are washed down by rain water or irrigation water to low lying areas, rivers or lakes, causing water pollution.

(iii) Industrial Pollution : Various industries are discharging effluents daily in great quantities which ultimately find their way into rivers, lakes and seas. Industrial wastes contain chemicals , such as lead, mercury, deteregents etc.

(iv) Oil Pollution : Oil leaked or spilled from ail tankers and offshore oil float over the sea water polluting the water and thereby causing damage to marine ecosystem.

Q. How ground water get does polluted?

Ans: Ground water is much cleaner and purer than surface water. About 10 percent of the rural and about 30 percent of the urban population use ground water for drinking and other purposes. However, even the ground water are now threatened with pollution from refuse dumps, septic tanks, agricultural chemical, disposal of industrial effluents which gradually move down and mix with ground water.

Q. What is BOD?

Ans : BOD means Biological Oxygen Demand. BOD is a measure of the amount of dissolved oxygen required by bacteria present in organic waste. More the demand, more is the degree of pollution.

Q. What are the effects of water pollution?

Ans : The effects of water pollution are —

(i) Abundance of microbes (ii) Creation of oxygen deficit in aquatic systems, (iii) Generation of plant nutrients and accelerated entrophication.

(iv) Algal or water blooms are created.

(v) Thermal pollution.

(vi) Increase of toxic race elements.

Q. What is entrophication?

Ans : Entrophication of closed water bodies is a phenomenon of pollution caused by a variety of factors. Eutrophication denotes the lowering or deterioration of water quality for domestic, recreational and other purposes. The continuous deposition of organic debris and its degradation by bacteria releases huge quantity of nutrients and moreover drainage of nutrients used for agricultural purposes in the nearby areas increases the level of nutrients further. Under this situation, algae and higher plants grow vigorously. Due to growth of algae and other plants, more and more organic matter is deposited raising the floor of the lake.

Q. What is thermal pollution of water?

Ans: Thermal pollution of water is caused by discharge of hot water into stream. Some industries use water for cooling purpose but return this water to the stream at a high temperature. Hot water affects biotic life in water. Some pathogenic forms may be favoured by the hot water at the expense of the normal fauna. Thus, ecological balance may be disturbed by discharge of hot water.

Q. What is mercury pollution of water?

Ans: Mercury pollution is one of the major concerns in areas where large number of paper industries are situated. Paper industries, use fungicides and algicides which contain mercury compounds Methyl-mercury is a highly persistent pollutant that accumulates in the food chain.

Q. Write about the measures to control water pollution.

Ans : (i) Preventive measures :

a. Proper disposal of sewage so that it does not find its way into water bodies.

b. Abuse of water must be checked.

c. Discharge of effluents into rivers, lakes and sea without treatment should be strictly prohibited.

d. Oil spill should be prevented.

(ii) Curative measures :

a.     Using septic tanks, oxidation ponds, filter beds, waste water treatment plants and sewage treatment plants etc. Solid waste may be removed before water is tipped into river or sea. The solid waste then can be converted into sludge, which is a valuable fertilizer.

b.     For drinking purposes, water is purified through various steps including biological treatment and disinfection.

c.Industrial water can be made less' polluted before discharge by biological treatment using water hyacinth. Water hyacinth has remarkable capacity to accumulate poisonous metals including radioactive substances.

d.     Certain strains of bacteria can reduce the oil spill effect and can use up cyanides and heavy metals if judiciously used.

e.     Scientific method of recycling all waste materials and effluents can reduce water pollution to a great extent.

Q. Write about the treatment of waste water.

Ans: Sewage or polluted water having organic ' matters can be treated to remove polluting matters. This is done in three stages.

(i) Primary treatment involves physical process of removing the suspended matters through screening, sedimentation and floatation.

(ii) Secondary treatment involves aeration of the polluted water to activate bacteriological action. Algae supply oxygen through photosynthesis and then the bacteria decompose the offensive organic materials and convert them to carbon dioxide, sulphate, nitrate, phosphorus and water. The bacteria are then killed by chlorine.

(iii) Tertiary treatment is done to remove phosphate, nitrate, sulphate etc;, from the water. The water released after all the treatment is considerably pollution free.

The sludge obtained in primary treatment can be treated anaerobically for decomposition of the organic materials which produces excellent fertilizer. Composting is another method of waste disposal. In the composting process all pathogenic organisms are destroyed.

Q.  Write about the industries and their pollutants which cause water pollution.

Ans: The industries and their pollutants which cause water pollution are as follows.

a.     Mining industries: hydrogen sulphide, ferrous sulphate, sulphuric acid, chlorides, metals, suspended solids.

b.     Steel Industries: Iron cyanide, copper oxide, chromium, cadmium, mercury, oil phenol etc.

c.     Chemical industries: Various types of acids and alkalis, sulphate, nitrates of metals, phospherus, silica, dye etc.

d.     Detergent industries: Alkalis, ammonia compounds, fat and fatty acids, sulphonated hydrocarbons etc.

e.     Paper industries: Bleaching substances, sulphides, cellulose fibres, organic acids.

f.      Food Industries: Putrefied organic matters, bacteria etc.

g.     Pharmaceutical industries: Organic solvent are residues, organic acids, intermediate products of drugs.