2. Why there is air pollution? Concentrations of certain substances become high enough to toxify the atmospheric environment. More traffic Commercial activities Industrial activities

3. Air pollution comes from three major sources 1. Combustion-engine vehicles such as gasoline powered cars 2. Industrial and community such as air condition or heating of homes and buildings 3. Indoor sources such as tobacco smoke

4. Hot weather and rising air Hot weather and rising air  helps disperse it  helps disperse it Rainfall Rainfall  wash out certain pollutants in the air  wash out certain pollutants in the air Temperature inversion Temperature inversion  traps air pollutants in lower atmosphere  traps air pollutants in lower atmosphere Still wind conditions Still wind conditions  inhibit effective dispersion of air pollutants  inhibit effective dispersion of air pollutants Northerly wind prevails in Southern China Northerly wind prevails in Southern China  make HK pollution more serious  make HK pollution more serious

5. Health Effects API Air Pollution Level Health Implications 0 to 25 Low Not expected 26 to 50 Medium Not expected for the general population 51 to 100 51 to 100 High Acute health effects are not expected but chronic effects may be observed if you are exposed to such levels persistently for a long time. 101 to 200 Very High People with existing heart or respiratory illnesses may notice mild aggravation of their health conditions. Generally healthy individuals may also notice some discomfort. 201 to 500 Severe People with existing heart or respiratory illnesses may experience significant aggravation of their symptoms. There may also be widespread symptoms in the healthy population (e.g. eye irritation, wheezing, coughing, phlegm and sore throats).

6. Environmental effect

7. How to control the air pollution? 1. Reducing Emissions from Vehicles tighter fuel and vehicle emission standards tighter fuel and vehicle emission standards cleaner alternatives to diesel cleaner alternatives to diesel control emissions from remaining diesels with devices that trap pollutants control emissions from remaining diesels with devices that trap pollutants strengthen vehicle emission inspections and enforcement against smoky vehicles strengthen vehicle emission inspections and enforcement against smoky vehicles promote better vehicle maintenance and eco-driving habits promote better vehicle maintenance and eco-driving habits

8. 2. Reducing Emissions from Industrial Sources and Power Plants The Air Pollution Control Ordinance The Air Pollution Control Ordinance  control emissions from power plants, industrial and commercial sources, etc  control emissions from power plants, industrial and commercial sources, etc A regulation introduced in 1990 A regulation introduced in 1990  reduced sulphur dioxide pollution to very low levels  reduced sulphur dioxide pollution to very low levels Emissions from power plants have been substantially reduced over the years Emissions from power plants have been substantially reduced over the years

9. Further suggestions for more effective control ￡ Use clean technology: choose the production technologies which use minimum electricity, fuels and solvents  reduces emissions of pollutant ￡ Do not use aerosol consumer products: like hair sprays, furniture polish, pesticides ￡ Use low solvent degreasers: use in the cleaning of oils, grease, or wax  reduces emissions of volatile organic compounds  reduces formation of ozone

10. Further suggestions for more effective control ￡ Switch off engine while waiting:  air pollution can be reduce,  save fuels and money ￡ Switch off the domestic appliances: turn off the fans and air-conditioner when you are not using ￡ Use energy efficient domestic appliances: save energy light bulbs, refrigerators.  reduce air pollution from the power station