Monday, June 17, 2013

Striving For Better Environment Part One

Ch. No. 14. Striving for Better Environment Part I

Q1. Write whether the following statements are true or false. If false write the correct statement:

1.       Cigarette smoke is bad for health of not only the smoker but also others.

2.       Almost all urban areas show low levels of air pollution.
False: Almost all urban areas show high levels of air pollution.

3.       Pollens, bacteria, fungal spores are also pollutants.

4.       Ecosystem can get severely disturbed due to natural disasters.

5.       Global warming is the desirable aspect of the intensified green house effect.
False. Global warming is the undesirable aspect of the intensified green house effect.

Q2. Answer the following in one sentence:

1.       Give the definition of a pollutant? Or what are Pollutants?
Ans. Pollutants are the products which affect the normal functioning of ecosystem and have adverse effects on plants, animals and humans.

2.       Name the diseases caused due to water pollution.
Ans. The diseases caused due to water pollution are cholera, typhoid, diarrhea, dysentery, hepatitis, polio and jaundice.

3.       Define water pollution.
Ans. When toxic substances enter into lakes, streams, rivers, oceans and other water bodies, they get dissolved or lie suspended in water or gets deposited on the bed, the quality of water deteriorates and affect aquatic system. This is called water pollution.

4.       What is Radioactive pollution?
Ans. Due to human activity, high energy radioactive particles mix in air, water and soil and pollute it. This is known as radioactive pollution.

5.       Who implement the laws related to pollution?
Ans. The Government of India implements the laws related to pollution.

6.       Name two causes of global warming.
Ans. Greenhouse gases and Ozone depletion.

7.       Name some monuments affected by acid rains.
Ans. Some monuments affected by acid rains are : Tajmahal (India, Mughal Islam), Acropolis of Athens (Greece, Ancient Greek), Longmen Grottoes (China, Buddhist).

Q3. Distinguish between:

1.  Degradable and Non degradable pollutants.

Degradable pollutants
Non degradable pollutants
1.       Degradable pollutants can be decomposed or degraded easily.
2.       Decomposition takes place by microorganisms and it requires less time.
3.       These pollutants again enter the biogeochemical cycles and become part of the natural nutrient cycle.
1.       Non – degradable pollutants cannot be easily decomposed.
2.       It requires more time and different techniques for decomposition.
3.       These pollutants will remain on the earth for years and create environmental pollution.

2. Primary and Secondary pollutant.

Primary pollutant
Secondary Pollutant
1.       Primary pollutants are the pollutants that are emitted directly from the sources and are found in the atmosphere in the form in which they were emitted.
2.       Examples: Ash, smoke, radioactive compounds, oxides of sulphur etc.
1.       Secondary pollutants are the pollutants that are formed in the atmosphere by chemical reactions between primary pollutants and atmospheric constituents.
2.       Examples: SO3 m O3 , Ketones, Peroxyacetyl nitrate.

Q4. Write short notes on :

1.       Acid rain:

i.  Acid rain is rain water containing harmful amounts of nitric and sulphuric acids.

ii.  When fossil fuels such as coal, wood, petroleum are burnt, nitrogen oxides and sulphur oxides are released into the atmosphere. These oxides are soluble in water.

iii. During rain, these oxides react with large quantities of water vapours of atmosphere to form acids like sulphurous acid, sulphuric acid, nitric acid and nitrous acid. These acids mix with mist, rain water drops or snow and change its composition. The rain or snow that falls to the ground is Acid rain.

2.       Eutrophication:
i.                     The enrichment of water bodies by inorganic plant nutrients like nitrate, phosphate occurring either naturally or due to human activity is Eutrophication.
ii.                    The process of eutrophication takes place due to introduction of nutrients and chemicals through discharge of domestic sewage, industrial effluents and fertilizers from agricultural fields.
iii.                  These promote excessive growth of phytoplankton and algae. When algae die, decomposition of organic substance use oxygen.
iv.                  This results in depletion of oxygen in water. The bloom of algae blocks penetration of oxygen, light and heat into the water body. As a result most of the organisms die below the surface of the water.

3.       Oil spills
i.                     Accidental release of oil into a body of water as from a tanker, off – shore drilling rig or underwater pipeline and wells often present a hazard to marine life and the environment.
ii.                    This oil spills forms a layer on the sea and prevent sunlight penetrating the water, which harms marine life.

Q5. Answer briefly:

1.       What adverse effect does ozone depletion have?
i.                     Stratospheric ozone is being destroyed mainly by chlorine atoms of chlorofluorocarbon (CFC) molecules.
ii.                    This has resulted a hole in the ozone layer in the stratosphere near Antartica. This hole allows the ultraviolet rays of the sun to reach the earth directly.
iii.                  These UV rays cause skin cancer, cataract in human beings. Ozone depletion can affect animals and plants as well.

2.       What are the different laws to prevent pollution?
The different laws to prevent pollution are
i.                     Water (Prevention and Control of Pollution) Act, 1974.
ii.                    Air (Prevention and Control of Pollution) Act, 1981.
iii.                  Environment (Protection) Act, 1986.

3.       Describe the main sources of water pollution.
Water pollution is caused by several sources both natural and man – made.
i.                     Natural sources:
a.       Due to heavy rains, minerals from land get washed into river and then oceans. This leads to uncontrolled growth of water weeds.
b.       Similarly dead animals, animal waste, ashes and chemicals released due to forest fires, sulphur compounds released after an earthquake get washed into water sources due to rain.
ii.                   Man made sources: Man – made sources such as city sewage and industrial water are the major sources of water pollution.
a.       Domestic sewage: Waste water originating from kitchen, bathrooms, toilet is domestic sewage. Domestic sewage contains wide varieties of dissolved and suspended impurities.
b.       Industrial waste: Waste materials like acids, alkalies, toxic metals, oil, grease, dyes, pesticides and even radioactive material are poured into the water bodies by many industrial units.
c.        Radioactive waste: Radioactive wastes are produced from industrial, medical, atomic power plants and scientific processes that use radioactive materials.
d.       Agricultural Runoffs: Intensive cultivation of crops causes chemicals from fertilizers and pesticides to seep into ground water.
e.        Oil spills: Accidental release of oil into a body of water as from a tanker, off – shore drilling rig or underwater pipeline and wells often present a hazard to marine life and the environment.
f.        Thermal pollution: the thermal power plants and other industries located near the rivers and sea use water for cooling purposes. They release recycled hot water into the water bodies leading to thermal pollution.

4.       How do biodegradable and non biodegradable waste cause land pollution?
i.                     Biodegradable waste are materials such as sewage that can rapidly decomposes by natural process. These pollutants become a problem when added to the environment faster than they can decompose.
ii.                    Since significant amount of urban solid waste is paper and food waste the majority is biodegradable in land fills.
iii.                  Non – biodegradable pollutants are materials that either do not decompose or decompose slowly in the natural environment. Non biodegradable materials like polythene bags, foot wear and plastic remain in soil for long periods.
iv.                  When industrial and urban wastes like chemicals, plastics etc, are dumped on land, they can accumulate and interfere with life processes.

5.       How do you protect soil from being polluted?
i.                     In recent years, excess use of fertilizers and pesticides is a major cause of deteriorating soil quality. So avoiding excess use of chemical fertilizers and enhancing use of organic nutrients is a major step in soil conservation.
ii.                    Bunds are built on the edge of field to check washing of soil. Excess water is drained by maintaining slope in the field to avoid water logging.
iii.                  Crop rotation is practiced to maintain soil quality. For example, legumes are planted between two major crops to increase nitrogen availability.

6.       What major harm is done to the human beings by air pollution?
Air pollution can affect our health in many ways with both short term and long term effects.
i.                     Short term effects include:
a.       Irritation of eyes, nose, mouth and throat.
b.       Respiratory infections such as bronchitis, pneumonia.
c.        Headaches, nausea and allergy.
d.       Asthma attacks
e.        Reduced lung functioning.
ii.                    Short term effects include:
a.       Chronic pulmonary disease
b.       Lung cancer.

7.       Give the impacts of Noise pollution on the human body.
Effects of noise pollution on human beings depend on noise intensity, frequency and exposure duration.
There are three types of effects on man:
i.                     Auditory effects: Auditory fatigue, deafness.
ii.                    Non – auditory effects: Communication interference, sleep interference, concentration interference, ill temper, annoyance, violent behaviour, mental disorientation, bickering and lose of working efficiency.
iii.                  Physiological effects: Nausea, fatigue, anxiety, visual disturbances, insomnia, hypertension, cardio vascular disease.

Q6. Suggest measures in the following situation:
1.    To avoid noise pollution in classroom.
To avoid noise in classroom make small changes in the classroom like.
i.                     Add curtains to the classroom.
ii.                    Use cork bulletin boards to walls.
iii.                  Placing sound absorbant panels on upper walls.
iv.                  Plastic buffer on furnitures can avoid noise caused due to dragging of furnitures.

2.   Bursting fire crackers in festivals and processions.
i.                     Use ecofriendly carbon free noiseless crackers which do not effect us in any way.
ii.                    Popularise the idea of not using crackers in festivals among public.

3.       The use of fossil fuels in villages.
The following measures helps to reduce the use of fossil fuels:
i.                     Rather than depend on fossil fuels, use energy from renewable (non conventional) sources like solar energy, biogasplant, windmill etc.
ii.                    Different types of engines are being used for various purposes. These engines are constantly consuming the sources of energy such as coal, petroleum etc. To reduce the use of fossil fuels, engines that reduce emissions to a large extent can be built and Compressed Natural Gas (CNG) can be used.

4.       To avoid pollution of land when you go on a picnic.
When we go on a picnic take care of the following measures to reduce land pollution.
i.                     Do not spit or urinate in the open space.
ii.                    Put waste food, plastic bags etc. Into the dustbin only.
iii.                  If it is a sea shore or river bank do not put plastic bags and other wastes into water. Instead we can bring back such waste if we cannot locate a dustbin.
iv.                  Use paper bags, tetrapack instead of polythene bags.

5.       The level of air pollution is very high in your locality.
The following measures can reduce air pollution in our locality:
i.                     Plant trees on road sides and develop gardens, parks and open grounds in the locality.
ii.                    A particular place can be provided for garbage collection and ensure that it is discarded daily.
iii.                  Give awareness to the people about the use of non conventional source of energy like solar energy, wind energy etc.

6.       To avoid noise pollution in silent zones.
i.                     Put silent zone sign board on these areas.
ii.                    Loud speakers and public address system cannot be used in silent zone.
iii.                  Honking on the horns to be prohibited.

7.       To minimize electricity consumption at home.
i.                     Switch off the electrical appliances like computer, fan, light, air conditioner. T.V. etc, when not in use.
ii.                    Use of washing machine, grinder should be reduced to twice in a week instead of daily.
iii.                  Use electricity saving devices such as more efficient light bulbs lime CFL and LED tube lights etc.

iv.                  Use Solar Water heater instead of electrical heaters.