$Cience Presentation

8/8/2019 $Cience Presentation

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Title : Pollution

Unit 3.2Teacher : Cik Fatimah


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Unit3.2The effectsof Environmental

PollutionWhat is environmental pollution ?

Environmental pollution is degradation ofthe quality of the environment due tothe increase of substances thatthreaten the balance of nature and the

health of living things.


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Typesof pollution

The majortypes of environmental pollutioninclude :-

(a) air pollution(b) water pollution

(c) soil pollution

(d) pollution caused by solid waste and hazardous

waste(e) noise pollution


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Most important oneCarbon dioxide is the main anthropogenic greenhouse

gas, followed by methane and nitrous oxide. Carbondioxide is emitted by the burning of fossil fuelsand by deforestation. Methane comes from

agriculture, waste, and fossil fuel production;nitrous oxide come from agriculture and industry.Chlorofluorocarbons (CFCs) are greenhouse gasestoo, but they have been phased out to protect the

ozone layer. Their replacements, hydrofluoro-carbons (HFCs), are even stronger greenhousegases


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Effectsofpollution

(i) Greenhouse Effect

Most of the heat does not escape as it istrapped in the atmosphere by greenhouse

gasses which in turn radiate infraredrays back to earth.


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(ii) The thinning of the ozone layer

The ozone layer absorb about 95-99% of ultravioletradiation and protects all living organisms on earthfrom the harmful and strong ultraviolet rays insunlight sunburn is due to UV rays that penetratethrough the ozone layers.

[ These rays are absorbed by plants and animal tissueswhich damage protein and DNA molecules ]


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(iii) Acid Rain

When sulphur dioxide dissolves in rain water, it

forms acid rain. Sulphur dioxide causesrespiratory difficulties such as asthma orbronchitis. It also destroys aquatic ecosystem

killing the fishes.[ PH value of water ]


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Air pollution affects health, damages agriculture, changesclimate .

The pollution problems started becoming serious with thebeginning of industrial revolution after the burning fuel likecoal & oil began. The addition of motor vehicles added tothe seriousness of the problem. These caused some seriousair pollution accidents in the Meuse valley in Belgium, in1948 Donora, Pennsylvania & in 1952 in London. Theseresulted in the death of several persons

Different types of Air pollution can be specified in thefollowing.

Gaseous - Carbon monoxide particulate smoke,pesticides , aerosol sprays.

Inorganic - Hydrogen fluoride.Organic - mercaptans.Oxidizing substances - Ozone.Reducing substances - Oxides of sulfur.Radio active substance-

Inert substance - Pollen or fly ash.


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(a)Effectof AirPollution tothe Atmosphere

It changes the dynamics of atmospherethrough the long & short wave radiationProcesses

Carbon dioxide increases the temperatureof surface due to which thetemperature

of the atmosphere will increase ,causeserious environment effects.


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(b) TheEffectsof AirPollution on Human & Animals

depend onexposuretime.

If the time of Exposure is small in the highconcentration the effect will be mild.

But if the exposure is for extended period,in the low concentration, the effect canbe bad

.


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(c)Effectsof AirPollution onvegetationisofmany kinds.

Sulfur dioxide can damage crops & trees.Hydrogen fluoride & nitrogen dioxide candamage ornamental plants & fruit trees.

Ozone & ethylene cause damage tovegetation.


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Sourcesof EnvironmentalPollution

(i) Uncontrolled use of of fossil fuels by carengines and factories

(ii) The disposal of by-products and etc.

(iii) Uncontrolled use of chemical fertilisers ,pesticides and fungicides in agriculture

(iv) The noise , smoke and poisonous gasesfrom vehicles and machinery

(v) Solid waste that is rubbish(vi) Chemicals called chlorofluorocarbons

( CFCs)


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(i)Uncontrolleduse of offossilfuelsby carenginesand factories

Sulfur Dioxide is one of the most dangerous gaseouspollutants for the mankind The lungs and mansrespiratory system are affected by it . It causesstrong irritation to the eyes and skin. It even

destroys the enamel on teeth. Many effects ofthis gas on man are permanent and irreparable.

Burning of oil and coal are the main reason for theproduction of this gas. Different kinds of coal and

oil have different amounts of sulphur That isreason more sulphur dioxide will produce from theburning. If coal with a high sulphur content isburned,more sulpur dioxide will be produced. andenter the atmosphere as sulphur dioxide gas.


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Motor vehicle exhaust fumes createincreasing amounts of ozone close to theearths surface. Ultraviolet radiation isresponsible for sunburn and skin cancer,

snow-blindness, cataracts and eye-damage, agingand wrinkling of skin, andreduced immunity to disease.


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INFO ONLY!!!

The enhancedgreenhouse effect was long acuriosity in the natural sciences. In the 1970s

the first climatologists were more worried

aboutglobal coolingas the next ice age wasoverdue andtemperatures were falling,probably because ofsulphur emissions (nowreduced because of concerns over acid rain).


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Air Pollution due to smoke from the factories


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(ii) Thedisposalofby-productsandetc.disposal ofby-products , wastes ,toxic

substances , radioactive substances , smokeand heat from factories

Waste chemicals are sometimes released intorivers & seas which can destroythe aquaticlife in the sea.


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Air Pollution due to burning fuels in industry

The toxic gas released into the air due to accident can bedisastrous.


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(iii)Uncontrolleduse ofchemicalfertilisers ,

pesticidesandfungicidesinagriculture

When these kinds ofchemicals are released

into the environment , the balance betweenliving things will be disturbed.


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Pollution due to automobiles

Drivers sight is NOTCLEAR !!


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(iv) Thenoise,smokeandpoisonousgasesfrom

vehiclesandmachinery

This usually occurs in in the city area wherethey are many developments projects

Such as Kuala Lumpur is commonly affectedby smog[ a mix of fog and smoke ] &noises

caused by heavy traffic and machinery


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(v) Solid wastethatisrubbish

Managing ofsolid waste

is a problembecausemost of thedisposalmethods

damagetheenvironment.


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Solid waste - RUBBISH


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(vi) Chemicalscalledchlorofluorocarbons(CFCs)

The release of chlorofluorocarbons (CFCs), especiallyfrom aerosols, by humans into the atmosphere(along-term effect)

From major volcanic eruptions (a short-term effect).

People are advised to use sunblocks and to limitexposure to direct sunlight. Here the Ozone

{triatomic oxygen} is formed by the action ofultraviolet radiation on the oxygen

In the atmosphere. High level of ultra violetradiation can be harmful to animal and plant


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People have made a group of chemicals called

ChloroFluoroCarbons, or CFCs. CFCs arefound in many items we use, from the airconditioners in cars, to the refrigeratorsand freezers in our homes, to the hair

sprays we use to keep our hair in place, andeven to medicinal products such as asthmainhalers. When we use this gas, it rises intothe air, and also reacts with ultravioletlight


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INFO ONLY!!!Ozone is a gas. It is concentrated in layer

25-30 Km above the earths surface.Ozone acts as a shield, protecting the

earth from the damaging effects ofultraviolet radiation from the sun..

It is thinning or complete loss of layer of

Ozone .It is 10 to 50 km above the earth.


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INFO ONLY!!!

Deforestation and coal burning release carbondioxide, which accumulates in theatmosphere.As a result the greenhouseeffect is strengthened, and temperaturesrise.


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Bout Ozone LayerJust like these lines above get thinner and thinner(if you are using Netscape), so does the ozonelayer around the earth. Ozone is a naturallyoccuring gas whose chemical symbol is O3. This is

not that much different from the oxygen that webreathe, O2. Ozone has just one more oxygen atomthan the oxygen in the air. However, this one tinydifference can make a big effect on our planet.While oxygen in its O

2

form is breathable, O3

isharmful to animals if inhaled. However, O3 ozonestays in a layer around the earth.


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This is where ozone plays its part. Ozone absorbsthese ultraviolet rays before it reaches the earth.When it absorbs these harmful rays, a chemical

reaction occurs where the ozone is split intooxygen gas (O2) and a free oxygen atom (O).Normally, the parts immediately rejoin togetherto form ozone again. This is where man and his

meddling around steps in. People have made agroup of chemicals called ChloroFluoroCarbons, orCFCs. CFCs are found in many items we use, fromthe air conditioners in cars, to the refrigeratorsand freezers in our homes, to the hair sprays we

use to keep our hair in place, and even to medicinalproducts such as asthma inhalers. When we usethis gas, it rises into the air, and also reacts withultraviolet light


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Air Pollution due to burning of coal In a Restaurent


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Effects of pollution and Global Warming


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THE END!!THE END!!


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Created by :

Hannah

Lee Kar Yan

Lee Hui YinKashvini

Shivagami

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$Cience Presentation