Chapter C4 Pollution

C4.1 What is pollution?

• Pollution refers to the undesirable changes in the quality of our natural environment.
• Pollution may
• upset the balance of natural ecosystem
• cause harm to the health , survival or activities of all living organisms, including human beings.

C4.2 Common Types of Pollution

There are four common types of pollution:

• air pollution
• water pollution
• noise pollution

4.  solid-waste pollution

 

C4.3 Causes of Pollution

1.       Urban development

• Rapid urban development causes a high concentration of human activities and a transport system.
• The rising consumption of matter and energy increase waste

 
2.       Industrial development
Rapid industrial development causes pollution, e.g.:
--air pollution is caused by the increased use of fossil fuels
--water pollution is caused by industrial sewage and waste heat
--noise pollution is caused by factories and power stations
--solid waste pollution is caused by industrial waste

3.    Man’s technological capabilities
Improvement in man’s technological capabilities causes:
-–an increase in energy generation and consumption
-–an increase in manufacturing activities
--an increase in the exploitation of natural resources
--an increase in the use of persistent pollutants and products,e.g. DDT

 

C4.4 Pollution in Hong Kong

Air Pollution in Hong Kong

-        Definition
Air pollution occurs when the air contains chemicals in such a high concentration that both the living and non-living environments are harmed

Pollution Sources in Hong Kong

Major sources of air pollution

Effect of air pollution

Power station Incinerators Gas plants Factories Construction sites vehicles

1. Increasing composition of carbon dioxide in the air affects microclimate  àThe greenhouse effect is enhanced and the temperature rises àAn urban heat island is found 2. High concentrations of air pollutants may cause smog àSmog reduces visibility and the duration of bright sunshine, and it is harmful to man’s health 3. sulphur dioxide (SO2) dissolved in rain cause acid rain which damages organisms , soil and buildings

Water pollution in Hong Kong

-        Definition:
Water pollution occurs when some substance or condition causes deterioration of water quality to such a degree that the water cannot meet a specific standard or the water cannot be used for a specific purpose.

-        Water pollution can be classified into two types:
-  coastal pollution
-  stream pollution

Major sources of water pollution	Effect of water pollutants
Domestic source Industrial source Transport source Agricultural source	1. Sewage increases the temperature and turbidity of water which encourages the growth of algae 2. Reduce the dissolved oxygen and threaten the life of aquatic organisms 3. A bad smell is created 4. Toxic chemicals kill water organisms 5. Untreated animal waste may spread disease.

C.   Noise pollution in Hong Kong

-        Definition:
Noise is usually defined as ‘unwanted sound ‘.   

 

Major sources of noise pollution	Effect of noise pollution
Neighborhood noise e.g. mahjong,karaoke Industrial and commercial noise e.g. factory machines, construction activities Traffic noise e.g. flight of aircraft	1. mental stress and heart disease 2.tmeporary or permanent deafness 3.disturbance of work and schooling

 

D.   Solid waste pollution in Hong Kong

-        Definition:
Solid-waste refers to any useless or unwanted solid material that has been disposed.

Major sources of solid waste pollution	Effect of solid waste pollution
Domestic source Industrial source Commercial sources Agricultural source	1.a bad smell is created 2.toxic chemicals and metals are harmful to man’s health 3.spoils beautiful scenery   4.spread disease

 

C4.5 Possible measures to reduce pollution in Hong Kong

• Urban planning and land use zoning
• urban renewal is précised in which polluting industries are relocated from mixed land use zones to the suburbs
• new town  are developed in which residential and industrial land uses are separated
• sewage treatment plants are planned in new towns

 

• Legislation
• Ordinances for pollution control are made
• main ordinances include:

Air Pollution Control Ordinance
Water Pollution Control Ordinance
Noise Control Ordinance
Waste Disposal Ordinance

• air and water control zones are set up

 

• Treatment and recycling of pollutants

a. Smoke , dust and gases are filtered before discharge by installation of equipment
b. Sewage, animal waste, glass, etc. are treated and recycled

 

D. Education
a. public awareness on environmental conservation is raised by education , e.g. , the school curriculums and world Environment Day

 

E. Specific measures for different types of pollution

• Solutions to air pollution

a. raising taxes to discourage private car ownership
b. monitoring air quality by setting up an air pollution index
c. encourage motorists to replace their old cars
d. encourage the use of LPG-powered vehicles

 

2. Solutions to Water pollution

• dredging of sludge in river and sea beds to speed up water flow
• regular infection of oxygen into river water
• practice of sewage charges according to polluter pays principle

3. Solutions to noise pollution

• construction of noise barriers along roads and railways
• Setting time-limits for piling and drilling
• Installation of double-glazed windows and air-conditioners in those

schools seriously affected by noise

4. Solutions to Solid waste pollution
a. sanitary landfill
b. encourage the use of biodegradable lunch boxes
c. composition

Worksheet

The following table shows the average daily solid waste in 1996 in Hong Kong.

Types of solid waste	Tones
Domestic waste	6,400
Commercial waste	1,000
Industrial waste	8,00
Special waste	500
Recovered waste	3,100
Construction waste	7,500
Total	19,300

   
(a) Draw a pie chart to show the proportion of different types of solid waste.                                                                                                                                           (3marks)

 

 

 

• What are the possible effects of solid waste pollution on the

environment?                                      (4 marks)
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( c)What are the roles of
(i) the government and                                        (4 marks)
(ii) citizens                                               (4 marks)
to alleviate solid waste pollution?

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