1. CHAPTER 9:
ENDANGERED
ECOSYSTEM
9.1 : HUMAN ACTIVITIES
THAT ENDANGER AN
ECOSYSTEM

2. Human activities which threaten the
ecosystem:
~development and industrialisation.
~increase in the number of motor
vehicles.
~increase the usage of pesticides and
chemical fertilisers in the agriculture
sector.
~uncontrolled deforestation.

3. The impact of human activities on the
ecosystem:
~soil erosion.
~flash flood.
~landslide.
~eutrophication.
~water,air,thermal and noise pollution.
~global warming.
~depletion or thinning of the ozone layer.
~climatic change.
~extinction of living things.

4. POLLUTION
(undesirable change in the physical chemical or
unbiological characteristic of the natural
environment,brought about by human
activities)
Air Water Thermal Noise
Pollution Pollution Pollution Pollution

5. Air Pollution
 Caused by the presence of pollutants in the air which
are harmful to life and the environment.
 Sources of pollution:
a)Burning rubbish,forest,solid waste.
b)Factories and industries burning of fossil fuel.
c)Motor vehicles release harmful gaseous.(CO)
 Effects:
~Cause respiratory diseases such as lung cancer.
~Dust that cover the plant will block the stomata.
~Soot and dust will blackens the buildings.
~Form haze which is harmful to humans.
~Reduces agricultural productivity.(e.g:photosynthesis)

6. Water Pollution
 Caused by domestic wastes,industrial wastes, soil
erosoin and agricultured waste that are discharged
directly into rivers.
 Souces of pollution:
a)Discharge of untreated sewage and domestic waste
into rivers.
b)Discharge of industrial waste.
c)Discharge of agricultural waste.
d)Oil spillage.
 Effects:
~Causes death to all life forms in the sea.
~Pollutes the beaches.

7. Eutrophication
 Occurs when inorganic nutrients and organic material
enter a river or a lake.
 Effects:
a)Encourages photosynthesising organisms in the
water ,particularly algae to grow rapidly.
b)Light intensity in the water is greatly reduced.
c)Causing the death of aerobic organisms when
depletion of oxygen in the water occurs.
d)The use up of oxygen supply by the bacteria will
increase the biochemical oxygen deman(B.O.D.)

8. Biochemical Oxygen Deman(B.O.D.)
 The amount of oxygen taken up by the micoorganism
that decompose organic waste matter in water.
 The uses of B.O.D.:
a)As a measure of certain types of organic pollutants
in water.
b)Measure the level of water pollution.
c)Indicates the presence of a microorganisms which
suggest a level of pollution.

9. Thermal Pollution
 The release of excessive heat into the environment.
 Sources of pollution:
a)Discharged of hot water from factories,nuclear
reactors and electric power stations.
b)Glass buildings.
 Effects:
a)Cause instant death to some species.
b)Distrupt the entire ecosystem.
c)Encourages rapid growth for algae.

10. Noise Pollution
 The occurrence of excessive noise in the environment
that disturbs the tranquality of life.
 Sources of pollution:
a)Trains and cars.
b)Construction sites.
c)Machines and equipment in factories.
 Effects:
a)Hearing problems.(deafness)
b)High blood pressure.
c)Emotional and mental disturbances.