1. BIOLOGY
CHAPTER 9
ENDANGERED
ECOSYSTEM

2. POLLUTION

3. AIR
POLLUTION

4. WATER
POLLUTION

5. THERMAL
POLLUTION

6. NOISE
POLLUTION

7.  THERMAL POLLUTION is the REALEASE OF EXCESSIVE HEAT
into the environment.
 SOURCES :
-discharge of hot water from factories, nuclear reactors and electric power
station.
-glass buildings.
 Electronic factories, electric power stations and nuclear reactors use water
as a cooling agent.
 The water becomes hot and the hot water is then channelled into the
rivers or seas causing the temperature of the water to increase.
 When the temperature of water is 5 degree Celsius above the normal
water temperature, aquatic organisms can die.
 The increased water temperature will increase the process of
decomposition and thus increase the B.O.D. value. This reduces the
concentration of oxygen in the water, causing the aquatic organism to die.
 The hot water also reduces the solubility of oxygen in the water. Hence,
the concentration of oxygen in the water is further reduced.
 Glass buildings reflect the sun’s rays from one building to the next
building. As a result, heat is trapped between the glass buildings and
increases the temperature in the surrounding area.

8.  NOISE POLLUTION is THE OCCURANCE OF EXCESSIVE NOISE
in the environment that disturbs the tranquillity of life.
 Can be measured by decibel (dB) unit.
 HUMAN EARS can only RECEIVE SOUNDS LESS than 80 dB
 Sources of noise pollution :
-aircrafts
-trains
-construction sites
- machines and equipment in factories
-traffic

9.  Effect of noise pollution :
-hearing problems (deafness)
-ear injury
-headaches
-emotional and mental disturbances
-high blood pressure
-psychological problems

10. SOURCE OF POLLUTION
Cement factories, quarries ,
, sawmills
factories and industries,
burning of rubbish, motor
vehicles
Burning of fossils fuels and
rubbish, car exhaust fumes
POLLUTANT
Dust
Dust and soot
Carbon monoxide
Carbon dioxide
Sulphur dioxide
Nitrogen oxide
HARMFUL EFFECT
Respiratory diseases
Cough and allergy
Dirty building
Cause haze
Reduce visibility
Prevent sunlight from reaching the earth's
surface and also block the stomata. Hence, the rate
of photosynthesis and the agricultural productivity
are reduce
Cause lung cancer
A toxic gas which combines easily with haemoglobin
as compared to oxygen. Therefore, it reduces the
efficiency of blood to carry oxygen.
Causes the greenhouse effect which increases the
atmospheric tempereture
Changes in climate cause floods, typhoons and
drought
Polar ice caps melt, causing floods
Irritates the eyes, respiratory tract and lungs
Damages lung tisuues
Causes acid rain
Acid rain corrodes metal structure in bridges and
limestones of buliding
Lower the pH level of soil and water
Causes a reduction in the yield of agricultural
products and death of aquatic organisms
Causes acid rain and effects of acid rain
Damages lung tisuues and causes bronchitis and
lung cancer
Irritates the eyes and respiratory tracts
Car exhaust fumes which
contain lead
Lead
Toxic, harmful and non-biodegrable. Hence, lead
can accumulate in the body. When, it reaches a high
toxic level it can cause retardation in children.
Activities of agricultural
industry
Agrochemical substances
Can be passed on in food chains and become
concentrated in the body, causing harm to the
organism because it is non-biodegrable
Hinder the physiological process
Toxic in the body
Nuclear power stations
Radioactive radiations
Causes mutation

11. Causes cancer and genetic diseases
Aerosol and foam industries
Chlorofluorocarbon (CFC)
Causes ozone layer
Causes global warming (changes in climate)
Skin cancer

12. SOURCE OF POLLUTION
Discharge of domestic
wastes
into rivers
Discharge of industrial
wastes
Discharge of agricultural
wastes (leaching from farms
to nearby rivers)
POLLUTANT
Untreated sewage (faeces
and
liquid wastes), rubbish and
detergents
HARMFUL EFFECT
Encourage growth of bacteria, causing diseases such
as cholera, typhoid and dysentry
Number of bacteria increases due to increased
concentration of nitrates and phosphates in
untreated sewage
Bacteria use up the oxygen supply in water to
decompose the intreated organic sewage and other
organic wastes. This reduces the concentration of
oxygen in the river and kills off fish and other
aquatic plants and animals. The decomposition of
dead plants and fish further increase the population
of bacteria in the water. This will reduce the
concentration of oxygen in the water.
Cause bad odour and unsightly view.
Rubbish that is non-biodegrable prevents sunlight
from reaching the plants in the river and prevents
difussion of oxygen. This threathens aquatic life.
High cocentration of detergents also reduces the
the concentration of oxygen in the water and
threatens the lives of aquatic organism.
Organic wastes from remains
of oil palms and rubber
plantations, toxic wastes
from
electronic factories such as
arsenic, lead, mercury and
zinc
Contaminate the water physically.
Decomposition of organic wastes reduce the
Fertilisers and faeces which
contain nitrates and
phosphates
The high concentration of nitrates and phosphates
in rivers or ponds results in eutrophication. The
nitrates and phosphates promote raid growth of
algae, the algae will later use up the oxygen supply
in the water, killing fish and other aquatic organisms
Agrochemicals such as
insecticides, pesticides,
Agrochemicals are non-biodegrable, highly toxic and
harmful as they can be passed on in the food chains
and accumulate in the bodies of aquatic animals
and
man. These chemicals wastes in significant amounts
herbicides and furgicides
concentration of oxygen in the water.
Accumulation of toxic chemicals that are
non-biodegrable through the food chain in aquatic
animals and man. These toxic subtances also
damage body organs and are harmful to man,
causing cancer and mutation.

13. are poisonous to aquatic animals and can damage
the organs in the body, cause cancer and
contaminate water supplies.
Oil spillage
Oil that spills from ships' oil
tanks
Causes death to all life forms in the sea.
Causes death of sea birds and lions.
Pollutes the beaches.