1 Human impact on the Environment Pollution I - Air pollution

2 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

3 Air pollutants 1. Carbon dioxide 2. Carbon monoxide 3. Sulphur dioxide 4. Nitrogen dioxide 5. CFCs 6. Lead particles 7. Particulates 8. Ozone

4 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?

5 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….)

6 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….)

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

8 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

9 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

10 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

11 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

12 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

13 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.