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Human impact on the Environment

Pollution I - Air pollution

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What is Pollution?

Any undesirable substances (pollutants) and energy that added to the environment so that it becomes less favourable for humans and other organisms.

There are four main types of pollution:– Air pollution– Water pollution– Land pollution– Noise pollution

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Air pollutants

1. Carbon dioxide

2. Carbon monoxide

3. Sulphur dioxide

4. Nitrogen dioxide

5. CFCs

6. Lead particles

7. Particulates

8. Ozone

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Which? Where? What? How?

You have to identify the problems on the pollutants with the help of these questions:

Where does the pollutant from?What effects do the pollutant have?How to minimize that pollutant?

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Carbon dioxide

Sources : From the burning of fossil fuels

Effects : Increase greenhouse effect global warming sea-level rise

Solution: Use other energy source (e.g. Solar, Geothermal, Wind, Water….)

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Carbon monoxide

Sources : From incomplete burning of fuel

Effects : Reduce the oxygen-carrying capacity of blood

Solution: Use other energy source (e.g. Solar, Geothermal, Wind, Water….)

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Sulphur dioxide – an acidic gas

Sources : From burning of sulphur-containing fuels

Effects : - Cause irritation of respiratory tract and eyes - Dissolve in rain water causing acid rain

acidify soil and water death of plants and animals

Solution : - Use other energy source (e.g. Solar, Geothermal, Wind, Water….) or use fuels with l

ow sulphur content - Use Liquefied Petroleum Gas (LPG) vehicles - Use water to absorb sulphur dioxide in

chimney

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Nitrogen oxides – acidic gases

Sources : From burning of fuels

Effects : - Irritation of respiratory tract and eyes - Causing acid rain

Solution : - Use other energy source (e.g. Solar, Geothermal, Wind, Water….)

- Use Liquefied Petroleum Gas (LPG) vehicle - Use water to absorb them in chimney

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Chloro-fluoro carbons (CFCs)

Sources : Man-made organic compounds for foaming and making aerosols

Effects : Break down the ozone layer in upper atmosphere which screen off ultraviolet causing skin cancer, lower crop yields and affect marine life

Solution : Banned the making and using of CFCs internationally in 1987

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Lead particles – a toxic heavy metals

Sources : Burning of fuels containing lead compound as anti-knocking compound

Effects : - Toxic and accumulate in the body - Affect mental development and cause hyperactivity in children - Damage to nervous system, red blood cells and kidneys

Solution : Use unleaded fuels and LPG vehicles

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Air particulates – inorganic and organic solid particles

Sources : From the incompletely burning of coal and oil

Effects : - Cause respiratory diseases - Darken buildings and vegetation - Reduce light intensity lower photosynthetic rate of plants and algae

Solution : Burning clean fuels, use other energy sources

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Ozone

Sources : Burning of fuel in extremely high temperature (e.g. in car engine)

Effects : - Ozone around us pollutants - Ozone in higher atmosphere prevent UV reaching ground level - Irritate respiratory system and eyes

Solution : Reduce the use of vehicles, or use electric vehicles

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Air Pollution control in HK

All the incinerators were closed down in 1990s.

Air Pollution Control Ordinance has been passed to control exhaust fumes.

Air Pollution Index is introduced in 1995 to provide information to public about the air quality.