biology form 4 3

7/29/2019 Biology Form 4 3

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BIOLOGY FORM 4

CHAPTER 9- ENDANGERED ECOSYSTEM -

.POLLUTION.

BY 4 SCIENCE 2013

- YAP MEI JEAN

- LOW YEN YEE

TEACHER - MR. SHAIK ALAWDEEN


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Pollution

AirPollution

WaterPollution

ThermalPollution

NoisePollution

P

O

L

L

U

T

IO

N


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Sources:

Factories that pump large amounts of carbon monoxide,carbon dioxide, oxides of nitrogen and sulphur dioxide into theatmosphere.

Exhaust fumes from motor vehicles contains soot, lead, carbonmonoxide and oxides of nitrogen.

Open burning and forest fire that release excessive smokeswith suspended solids and pollutant gases such as carbondioxide and carbon monoxide.

Coal-fired power stations that release large amounts of carbondioxide into the atmosphere.

Quarries, cement factories and sawmills which emit dusts intothe air.

The condition when pollutants enterthe air from various sources.


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Air Pollution


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Effects Formation of haze and excessive smokes in air that:

-Decrease light penetration and cause the deposition of dust and

carbon particles on the stomata of leaves. Photosynthesis would

be affected and crop production of reduced.

- Reduce visibility and may lead to the closure of airports.

-Coat the buildings and structures with layers of carbon and dirt

thus increase the maintenance coats.

- Cause health problems such as bronchitis, rhinitis, eye irritation

and conjunctivitis.


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Acid Rain

Gases such as nitrogen oxides and

sulphur dioxide combine with water

vapour in the atmosphere, forming

nitric acid and sulphuric acid which

then fall as acid rain.


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- Soil becomes more acidic and less suitable for planting of

crops.

- Salts in the soil would be dissolved and carried into rivers and

lakes. High level of certain salts such as aluminium salts may

be poisonous to aquatic organisms.

- Erosion of bridges, metal railings and also the limestone or

marble structures.

- Affected plans growth when chlorophylls and photosynthesis

tissues are destroyed.

The adverse effects of acid rains are:


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Trees badly damaged by acid rain.


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A system adopted by MalaysiaGovernment to indicate the levelof air pollution based on itshealth impact

Air Pollution

Index(API)

API Descriptor

0

50 Good

51 100 Moderate

101 200 Unhealthy

201 300 Very unhealthy

> 300 Hazardous


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- The condition when pollutants enter the water sources such aslake, rivers and sea from various activities.

Sources:

Domestic activities

-The disposal of solid wastes like rubbish, detergents and sewagefrom housing areas.

Industrial activities

-Untreated waste toxic chemicals such as mercury, lead, zinc.

-Radioactive waste substances.Agricultural practices

-The run-off excessive use of fertilisers, pesticides and herbicides.

Shipping activities

- Crude oil spills from tanker ships.


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Leaching of inorganic fertilisers / input of untreated sewage / run off animal

waste

Increase in mineral nutrients into bodies of water

Algae bloom (rapid growth of algae)

Death of other aquatic photosynthetic plants and algae

Decomposition by bacteria (rapid growth of bacteria)

Bacteria use up oxygen

Aquatic organisms die

Restricts the penetration of light into the water

BOD level increase


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High BOD and the spread of water borne diseases.

-The presence of organic materials in water promotes rapid

growth of micro-organisms such as algae, bacteria, and protozoa.

These lead to the increase of BOD (Biological/Biochemical Oxygen

Demand). When dissolved oxygen in water is reduced, the life of

the living aquatic organisms would be affected. Thus, the high

BOD value indicates that the level of water pollution is high.

Water polluted with pathogenic bacteria, protozoa and virus may

spread infectious diseases such as cholera, typhoid, dysentery and

hepatitis A.


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Accumulation of toxic materials.

-The illegal dumping of waste and the discharging of effluent from heavy industries are

the main sources of toxic pollution in water resources.

-Heavy metal ions such as arsenic, Cadmium, mercury, copper, zinc, and organicchemicals toxics such as DDT, benzene in water would accumulate in the benthic

organisms and the producers, which would be passes up to the higher level of

organisms via food chains. Bioaccumulation of these metal ions and toxic chemicals

would cause devastating effects in human such as damage of body organs and gene

mutation that would lead to cancer and leukaemia.

Environment disaster

Spillage of crude oil from tankers into the sea can cause major environment disaster.

The layer of oil on the surface of sea would:

-Prevent the light from penetrating into the sea water, thus the photosynthetic activities

of aquatic plants are disturbed.-Reduce the exchange of oxygen between the air and the sea water, thus affect the

organisms living in the water.

-Poison certain animals when they come in contact with this oil.

-Damaged animals fur and birds feathers when coated with oil, thus they could neither

fly nor escape themselves from predators. They could not also keep their bodies warm

buy will die by freezing to death.


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Definition: The condition where the temperature of the surrounding increase when excessheat is released into the environment.

Sources:

Reflection of heat from glass buildings that increases the temperature of surrounding air.

Factories that use water to cool down machineries release warm water into the rivers,lakes or seas.

Nuclear reactors release hot water into the river, lakes or seas.

Effects:

Many aquatic organisms would die as they cannot tolerate the rise in the surroundingwater temperature. The increase in the water temperature of as much as 5 above thenormal water temperature would be fatal to aquatic organisms that only survive within acertain range of temperature.

Increase in BOD value when the metabolic rate of aquatic organisms increases.

Warm water contains less dissolved oxygen for the respiration of aquatic organisms such

as the planktons, thus the food webs are distured when planktons die.

Migrations of organisms occur when the food chains are affected and the ecosystembalance is disturbed.


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Noise PollutionDefinition: The condition where the unwanted human-created arounddisrupts the environment or because harmful to human health andwelfare.

Sources:

Trains

Aeroplane

Motor vehicles

Factory machines

Drilling machines and pilling in construction sites.

Effects:

Decrease in hearing sensitivity when someone is continuously exposed tothe noise level at about 80 decibels (dB) and above, which will finally leadto deafness (since the safe noise level is < 55dB according to WHO and thenoise at 140 dB damages the auditory organs).

Development of health problems such as indigestion. ulcers, high bloodpressure , coronary disease, depression and headaches.


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Noise level(dB)

Noise types Effects

40 - 60 Normal conversation Safe for the ear.

80 - 100 Food blender, lawn

mower, heavy traffics,

tractors

Annoying and continuous exposure leads

temporary hearing damage. If not treated can

cause permanent damage.

> 100 Piling, drilling, rock

concert

Unprotected regular exposure cause

permanent hearing loss.

> 125 Jet engine, shotgun High potential for hearing loss.

Effects that according to noise level


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Noise intensity

of daily human

activities


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