SEC23 GEOG Chapt9 Pollution

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CHAPTER 9CHAPTER 9Pollution in the WorldPollution in the World


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


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.


Lead-in: Haze Blues Extension ActivitySmog 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


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.


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.


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.


Air Pollution

Causes of air pollutionNatural 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.


Air Pollution

Causes of air pollutionHuman 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.


Air PollutionExtent 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.


Air PollutionExtent of air pollutionHealth 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


Air PollutionExtent of air pollutionTraffic 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.


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.


Water Pollution

Causes of water pollutionImproper 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.


Water Pollution

Causes of water pollutionImproper 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.


Water PollutionCauses of water pollutionOil 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.


Water PollutionCauses 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.


Water Pollution

Extent of water pollutionEndangering 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.


Water PollutionExtent of water pollutionEndangering 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


Water Pollution

Extent of water pollutionNegative 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.


Water Pollution

Extent of water pollutionEconomic 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


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.


Land PollutionCauses of land pollutionImproper 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


Land PollutionCauses of land pollutionExcessive 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


Land Pollution

Extent of land pollutionNegative 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.


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.



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



National effortsEnforcing 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



National effortsUsing 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.



National effortsDeveloping 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.



National effortsEducating 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.



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



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.


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.


Noise Pollution

Causes of noise pollution• Traffic is a common cause of noise pollution,

especially in urban areas.


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.


Noise Pollution

Causes of noise pollution• Construction and other human activities

contribute to noise pollution.


Drilling, piling, knocking and use of heavy machinery.

Cheering spectators in a stadium.


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 and3. affects our school and work performance.


Prolonged exposure to noise raises our blood pressure, heart rate, anxiety and stress levels.


Noise Pollution

Measures to reduce noise pollutionNational 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.


Mufflers can be installed in noisy equipment or in vehicles to absorb noise.


Noise Pollution

Measures to reduce noise pollutionIndividual 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.



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.



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.



Environmental planning in SingaporeKey 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 and3. reduce the need for new incineration plants to one

every ten to 15 years.



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.



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.



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.



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.



Environmental planning in SingaporeBuilding 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.



Environmental planning in SingaporeBuilding 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.



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.


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.

Date post:	27-Jan-2015
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SEC23 GEOG Chapt9 Pollution

Education