View
161
Download
0
Embed Size (px)
Citation preview
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
CHAPTER 9 Pollution in the World
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Learning Outcomes
You Will Learn:
• what air, water and land pollution are
• what noise pollution is (Special/Express stream only)
• about the causes and extent of pollution
• about the measures taken to reduce pollution
• about Singapore’s approaches to environmental
protection
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Lead-in: Cough! Yuk!
(Suggested Answers)
1. In the first photograph, the fire produces smoke that
pollutes the air. It has also destroyed the habitats of many
plants and animals. In the second photograph, the improper disposal of rubbish has polluted and choked the
water channel, possibly causing the water to stagnate
and allowing pests like mosquitoes to breed.
2. Human activities can be the causes of these environmental damages. In the first photograph, people
may have set fire to agricultural plantations and forests to
clear the land. Such a scenario is common in countries
like Indonesia. However, it is also possible that the fire is caused by natural events like hot weather and drought. In
the second photograph, people have irresponsibly
disposed of their rubbish and caused water pollution.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Lead-in: Haze Blues Extension Activity
Smog is increasingly enveloping the city of Hong
Kong. Sometimes the air quality is so bad that visibility
declines to only a few metres. What could have
caused the smog to occur and what consequences
does it have on people and the environment?
Smog covering the city of Hong Kong
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Pollution and Waste • Pollution is the introduction of substances into the
environment such that it results in unpleasant or
damaging effects on people, animals, plants
and buildings. Human activities and natural
events cause pollution.
• Waste refers to materials that are useless and no
longer wanted. Households, agricultural and
industrial activities generate waste.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Pollution and Waste • One type of pollution can often lead to other
types of pollution.
• For example, air pollution from mobile and
stationary sources, like motor vehicles and
factories, lead to the formation of acid rain
which eventually causes water pollution.
Air pollution can lead
to water pollution.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Air Pollution
• Air pollution occurs when substances such as
dust, smoke or harmful gases are released into
the environment.
• Smog, a serious form of air pollution, forms when
air pollutants like dust and smoke particles
combine with water vapour and toxic gases.
• Smog is common in industrialised areas of China,
India and some eastern European countries.
‘Brown-air’ smog over Sao Paulo, Brazil. Nitrogen dioxide gives the smog its
brown colour.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Air Pollution
Causes of air pollution Natural causes of air pollution • Volcanic eruptions
• Forest fires
High temperatures and low rainfall can create dry conditions which
spark forest fires.
Large amounts of ash, smoke and gases are released into the air
during a volcanic eruption.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Air Pollution
Causes of air pollution Human causes of air pollution • Industries
• Motor vehicles
• Construction work Vehicle emissions,contain harmful gases like carbon
monoxide and nitrogen oxides.
Manufacturing industries emit large amounts of dust and
smoke into the air. Construction work pollutes the air
with dust and smoke particles.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Air Pollution
Extent of air pollution • Air pollutants can be carried by winds from their
source to other places, regions and countries.
• For example, smoke carried by winds from burning
forests in Indonesia often causes haze in the
Southeast Asian region.
Haze observed over the Straits of
Malacca and Peninsular Malaysia.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Air Pollution Extent of air pollution Health problems • Dust and smoke can irritate throats and eyes and
cause breathing difficulties for people. • People can develop respiratory problems such as
bronchitis and asthma due to prolonged exposure to dust and smoke.
• Air pollutants such as nitrogen oxide and sulphur dioxide can cause severe health problems and increase the risk of developing lung and heart diseases.
Toronto, Canada, covered in smog
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Air Pollution Extent of air pollution Traffic hazards • When countries experience haze, visibility
conditions deteriorate and airports may have to suspend operations and ground flights.
• Bad visibility conditions caused by haze may make driving inconvenient and dangerous.
Environmental problems • Acid rain is rain that is many times more acidic
than normal rain due to the sulphur dioxide and nitrogen oxides present in the air.
• Acid rain destroys forests, kills aquatic life and corrodes buildings.
• It is a common problem in places that are heavily industrialised.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Water Pollution
• Water pollution occurs when pollutants are
discharged directly into water bodies such as rivers,
lakes and seas.
• It also occurs when air and land pollutants are blown
by wind or washed by rain into water bodies.
Urban settlements discharge many forms of pollutants into canals, drains and sewer pipes which eventually find their way into the rivers and seas. Sources of pollutants include factories, sewage treatment plants, runoff of chemicals from agricultural plantations and live-stock farms.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Water Pollution
Causes of water pollution Improper disposal of sewage • Sewage refers to solid or liquid waste that is
produced by households or industries. It contains
human waste, detergent and chemicals.
• When untreated sewage is discharged into rivers
and seas, water pollution occurs.
A sign warns people that the
river is polluted with sewage.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Water Pollution
Causes of water pollution Improper disposal of sewage • Industrial waste contains large amounts of toxic
chemicals. Heavy water pollution occurs when
untreated industrial waste is irresponsibly
discharged into water bodies.
• Sewage is treated at sewage treatment plants to
remove its waste products before it is released into
water bodies.
Sewage treatment process
Some substances in detergents, sprays and even body lotions and shampoo are non-biodegradable and cannot be removed by sewage treatment processes.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Water Pollution
Causes of water pollution Oil spills • Oil spills occur when the hull of an oil tanker is torn
by sharp rocks or when a tanker collides with another ship, causing the oil it is carrying to spill into the sea.
• In 1989, the Exxon Valdez oil tanker went off course, hit rocks, and released large amounts of oil into Alaska’s Prince William Sound. This accident cost some US$2.1 billion to clean up.
• In 2002, the oil tanker Prestige sank off the coast of Spain and over two years leaked twice as much oil as the Exxon Valdez.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Water Pollution
Causes of water pollution • However, much more oil is released from other
smaller, day-to-day and less visible activities.
• Current studies have shown that most ocean oil
pollution comes from activities on land.
• These include normal operation of offshore wells,
washing oil tankers, loading and unloading of oil
tankers at ports, and leaks from oil pipelines,
refineries and storage tanks.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Water Pollution
Extent of water pollution Endangering plant and animal species • In an oil spill, sea birds cloaked with oil will freeze to
death as their feathers cannot insulate air to protect
them from the cold.
• The oil also clogs the birds’ feathers and makes
them unable to fly or float on water. They will drown
as a result.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Water Pollution
Extent of water pollution Endangering plant and animal species • Household waste contains excess nitrogen and
phosphorus which encourage the growth of algae on river and ocean surfaces.
• With the algae covering the water surface, sunlight cannot penetrate and reach the aquatic plants beneath the water surface, causing them to die as photosynthesis cannot occur.
• As a result, aquatic and marine animals that depend on these plants for food will be affected.
Algae covering the
surface of a river
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Water Pollution
Extent of water pollution Negative impact on human health • Chemicals and toxic metals contaminate shellfish beds, kill
spawning fish and accumulate in the tissues of bottom marine
feeders.
• These chemicals and toxins can be passed on in the food chain and eventually reach us when we consume the
contaminated animals.
• People, especially in poor developing countries, can suffer
from cholera and typhoid when they drink contaminated water.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Water Pollution
Extent of water pollution Economic loss • Oil spills threaten the fishing industry and fishermen’s
livelihood. • Oil spills can also pollute beaches and affect tourism. • Cleaning up oil spills requires an international effort and
is a very expensive task. Scientists have estimated that no more than 15 percent of the oil from a major oil spill is recovered in a cleanup operation.
• The cheapest way and the most effective approach is to prevent oil pollution.
Beach pollution in Beirut, Lebanon
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Land Pollution
• Land pollution occurs when waste is not disposed of
properly on land, or when chemicals are used
excessively on farms.
• Improper disposal of waste and the excessive use
of chemical fertilisers and pesticides are some
causes of land pollution.
A landfill. It is important is to realise that we can never truly throw anything away. Waste often ends up somewhere and can cause land and other forms of pollution.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Land Pollution
Causes of land pollution Improper disposal of waste • With the increase in the world population, more
goods and services are consumed and more waste
is produced.
• Without proper waste disposal management, the
rubbish is often left at public places or illegal
dumping grounds.
A slum in Smokey Mountains, the Philippines Proper waste disposal management
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Land Pollution
Causes of land pollution
Excessive use of chemical fertilisers and pesticides
• When chemical fertilisers and pesticides are used to
improve soil fertility or to eliminate pests, the soil
gets contaminated.
• In addition, these chemicals also pollute
groundwater and may find their way into rivers and
cause water pollution.
A man spraying pesticide over some crops
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Land Pollution
Extent of land pollution Negative impact on human health • Improper disposal of waste attracts pests which
spread germs and diseases.
• Farmers exposed to large amounts of pesticides risk
developing cancer and liver failure.
Poisoning of animals • Pesticides and chemicals may pass on into the food
chain and affect the reproductive systems and
survival of some animals.
The American Bald Eagle is now endangered
because of the use of pesticides like DDT.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Measures Taken to Reduce Pollution
International efforts • Pollution can become a regional problem. Therefore,
governments and international organisations like the
United Nations Environment Programme (UNEP) need to
work together to resolve the problems associated with
pollution.
• For example, after the 1989 Exxon Valdez oil spill, many
countries have made it compulsory for oil tankers to
have double hulls to prevent oil spills.
The United States has implemented the Oil Pollution Act of 1990 which requires all oil tankers to have double hulls by 2015. The European Union has also voted to ban single hull
oil tankers from their waters by 2010.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Measures Taken to Reduce Pollution
International efforts • The United Nations organised the Earth Summit in
1992 and 2002 for world leaders to commit their
countries to sustainable development.
• Sustainable development is development that
meets the needs of present generations without
compromising the ability of future generations to
meet their own needs.
Beijing, China
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Measures Taken to Reduce Pollution
National efforts Enforcing laws and regulations • Laws are enacted and enforced to monitor, reduce
and prevent different forms of pollution.
Using alternative sources of energy • ‘Clean’ energy which does not release harmful
pollutants into the environment can be utilised.
Examples are solar and wind energy and
hydroelectricity.
Windmills in Spain
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Measures Taken to Reduce Pollution
National efforts Using advanced technology • Sewage treatment plants can be built to treat waste
water before releasing it into the environment. Developing proper waste disposal methods • There are two methods to carefully manage the
disposal of waste — landfill and incineration. For example, Singapore has built the Pulau Semakau Landfill to manage solid waste. However, landfills are expensive to build and maintain and not a long-term sustainable solution to solid waste management.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Measures Taken to Reduce Pollution
National efforts Developing proper waste disposal methods • By 2009, Singapore will have five incineration plants
to burn solid waste. Although incineration plants can produce electricity and reduce the volume of waste, they still emit air pollutants and are very costly to build.
• The government, under the Singapore Green Plan 2012, has decided to reduce the amount of solid waste generated. This is done by reducing waste going through incineration plants and landfills and by promoting waste recycling and minimisation.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Measures Taken to Reduce Pollution
National efforts Educating the public • An effective method to reduce pollution is to
encourage people and industries to cut down on waste production.
This can be done through public talks and campaigns aimed at informing people about the harmful effects of generating excessive waste.
Environmental conservation concepts like the 3Rs — Reduce, Reuse and Recycle, can
be promoted through public education.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Measures Taken to Reduce Pollution
Individual efforts • As individuals, we can help protect the environment
by adopting practices which reduce waste.
Go ‘green’
Ride bicycles, take public transport, recycle old newspapers
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Measures Taken to Reduce Pollution
Individual efforts • We should be informed about national and international plans
for environmental conservation so that we can do our part to
help. • We can help protect and conserve the environment by
reducing, reusing and recycling waste.
• It is important to realise that the best and cheapest way to
deal with waste and pollution is to produce less pollutants and
to practise the 3Rs for most of the materials we use.
Be informed and get involved.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Noise Pollution
• Noise pollution occurs when unwanted sounds are
added to the environment by vehicles, industries,
household gadgets or even loud music.
• Noise pollution affects our quality of life.
Special/Express stream only
The different degrees of loudness of noise are measured in decibels. Noise above 130 decibels hurts the ears and damages hearing.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Noise Pollution
Causes of noise pollution • Traffic is a common cause of noise pollution,
especially in urban areas.
Special/Express stream only
An airplane taking off from a runway produces noise of about 120 decibels.
Vehicles on a busy street creates about 60 to 90 decibels of noise.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Noise Pollution
Causes of noise pollution • Construction and other human activities contribute
to noise pollution.
Special/Express stream only
Drilling, piling, knocking and
use of heavy machinery. Cheering spectators in
a stadium.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Noise Pollution
Extent of noise pollution • Noise pollution degrades our quality of life and has
a negative impact on our health.
• Long-term exposure to noise pollution potentially:
1. damages our hearing ability,
2. increases our heart rate, anxiety and stress
levels, leading to high blood pressure and
3. affects our school and work performance.
Special/Express stream only
Prolonged exposure to noise raises our blood pressure, heart rate,
anxiety and stress levels.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Noise Pollution
Measures to reduce noise pollution National efforts • Laws and regulations can be enforced to regulate
the acceptable noise levels produced by vehicles,
workplaces, industries and construction sites.
• Various noise reduction methods like erecting
sound barriers, planting trees and shrubs, covering
walls with sound-proofing materials and installing
mufflers in vehicle engines can be used to reduce
noise pollution.
Special/Express stream only
Mufflers can be installed in noisy
equipment or in vehicles to absorb noise.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Noise Pollution
Measures to reduce noise pollution Individual efforts • We can reduce noise pollution by minimising the
amount of noise we create through our daily activities.
• For instance, to show consideration for our neighbours and to make our environment a pleasant one, we can listen to music using headphones at night instead of playing loud music from speakers.
Special/Express stream only
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Environmental Protection in Singapore
Environmental planning in Singapore • The Ministry of the Environment and Water Resources
(MEWR) is responsible for the state of environmental
cleanliness in Singapore.
• The National Environment Agency (NEA), a statutory board
under the MEWR, protects and enhances Singapore’s clean
living environment by monitoring, reducing and preventing
environmental pollution, through waste management, waste
recycling and energy conservation.
• The NEA also ensures a high standard of public health,
cleanliness and hygiene in Singapore.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Environmental Protection in Singapore
Environmental planning in Singapore • The Singapore Green Plan (SGP2012) lays out the goals
and objectives of environmental sustainability in
Singapore for the next decade.
• The SGP is reviewed and revised every three years to
ensure its relevance.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Environmental Protection in Singapore
Environmental planning in Singapore Key environmental protection efforts: Clean land • Efficient and effective waste disposal and reduction
methods are developed to ensure Singapore’s residential, commercial and industrial areas remain waste and rubbish free. Waste in Singapore is mainly incinerated and the ash remains buried in landfills.
• By 2012, under the SGP2012, Singapore aims to: 1. increase overall recycling rate from 44 percent to 60 percent, 2. extend the lifespan of Pulau Semakau Landfill to 50 years and strive for ‘zero’ landfill and 3. reduce the need for new incineration plants to one every ten to 15 years.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Environmental Protection in Singapore
Key environmental protection efforts: Clean land • Why do you think Singapore aims for ‘zero’ landfill? Do you
think it is possible for Singapore to achieve ‘zero’ landfill?
Why?
• The Tuas South Incineration Plant and Pulau Semakau
Landfill were built at an exorbitant cost of $900 million and
$610 million respectively.
• The substantial cost incurred in building new incineration
plants and landfills has discouraged the use of such facilities
as a sustainable solution to waste disposal management in
Singapore.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Environmental Protection in Singapore
Key environmental protection efforts: Clean land • As such, the MEWR has adopted waste minimisation
policies to reduce the volume of solid waste going
through our incinerators.
• These waste management policies have seen modest
success and our overall recycling rates have gone up,
from 40 percent in 2000 to 49 percent in 2005.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Environmental Protection in Singapore
Key environmental protection efforts: Clean air • The SGP2012 aims to reduce air pollution by
encouraging industries and individuals to reduce
energy consumption and use less polluting fuels like
natural gas in power stations and vehicles.
• Singapore has increasingly used natural gas to
generate electricity in all its power stations. In 1999,
natural gas stood at about 20 percent of fuel
composition of the total electricity generated. In 2004,
the number rose to about 69 percent.
• A major review of the entire transportation system is
also underway to encourage more people to use
public transport in the future.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Environmental Protection in Singapore
Key environmental protection efforts: Clean
water
• Through the efforts of the Public Utilities Board
(PUB), Singaporeans can obtain adequate
supply of clean water at an affordable cost.
Our drinking water quality is excellent and meets the Guidelines for Drinking-Water Quality
set by the World Health Organisation.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Environmental Protection in Singapore
Environmental planning in Singapore Building partnerships • Singapore believes in building partnerships with other
countries and international organisations to share
experiences and work together to resolve
environmental problems.
• For example, Singapore has signed many major
international environmental agreements like the
Montreal Protocol, Basel Convention, Stockholm
Convention, Rotterdam Convention and the Kyoto
Protocol.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Environmental Protection in Singapore
Environmental planning in Singapore Building partnerships • Apart from foreign partners, Singapore also actively
engages other local governmental and non-
governmental organisations (NGOs) such as nature
societies and environmental clubs, in environmental
issues and protection.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Environmental Protection in Singapore
Keeping Singapore clean and green • As a result of our efforts to protect the environment, Singapore has
earned the distinction of being a ‘Clean and Green City’.
• As Singapore continues to grow, we must ensure that our
environment is not compromised and damaged at the expense of
economic growth.
• For our environmental efforts to truly succeed, everyone of us
living in this city must play a part in environment conservation and
protection.
Grey or Green? It’s your choice.
Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Skills Builder: Suggested Answers
1. When the people of Bhopal breathed in the toxic gases,
they coughed, vomited and their eyes became
inflamed. Some of the people were not able to
communicate with each other. Some lost their sight.
Many people also lost consciousness.
2. An accident like the Bhopal disaster could happen in
Singapore if we are not vigilant in protecting our
environment. To prevent such an accident from
occurring, the government needs to enforce stringent
laws to regulate the manufacturing process of toxic
chemicals like pesticides. In addition, the
manufacturing factories of toxic chemicals should be
located away from residential and commercial areas.
3. No. In an event of a disaster, many people living near
the pesticide factory will lose their lives and experience
severe health damage.