Environmental Issues and Legislation Notes

Environmental Issues and Legislation

1. Air Pollution

  • Air Quality:
    • Potentially harmful gases and particles are emitted into the atmosphere globally.
    • Causes damage to human health and the environment.
  • Sources of Pollutants:
    • Stationary sources.
    • Mobile sources.
    • Indoor sources.
  • Concentrations of Pollutants:
    • Index of mass concentration of particles.
    • The mass concentration of particles less than 2.5 m diameter (PM2.5) is a means of measuring the total gravimetric concentration of chemically distinct classes of particles.

2. Classification of Air Pollutants

  • Suspended particulate matter.
  • Gaseous pollutants.
  • Odours.

3. Components of the Atmosphere

  • Harmful gases: O3, SO2, NO2, CO, and a wide range of VOCs.
  • Particulate matter: Solid and liquid particles ranging from a few nanometers to about 0.5 mm.

4. Sources of Air Pollutants

  • Anthropogenic: Involving combustion.
  • Natural: Dust storms, volcanic action, forest fires, formation of radioactive particles from gases.
  • Tsing Ma Bridge Air Pollution example.

5. Factors Affecting Concentrations of Air Pollutants

  • Strength of sources.
  • Efficiency of dispersion: wind speed, turbulence.
  • Sunlight.
  • Traffic density.
  • Temperature inversions.
  • Geographic location of cities.

6. Specific Air Pollutants

  • Carbon Monoxide (CO):
    • A colourless, odourless, and tasteless gas.
    • By-product of incomplete combustion of carbon-containing fuels.
    • Principal source in urban areas: automobiles.
  • Nitrogen Oxides (NOx):
    • Group of gases from high-temperature combustion processes.
    • Nitric oxide (NO): Emitted during combustion and converts into nitrogen dioxide.
    • Nitrogen dioxide (NO2): Corrosive, highly oxidizing light brown gas with a pungent smell.
  • Sulphur Dioxide (SO2):
    • Colourless, reactive gas, odourless at low concentrations but pungent at high concentrations.
    • Emitted during fossil fuel combustion and processing of sulphur-containing ores.
  • Ozone (O3):
    • Formed by the action of UV light on nitrogen oxides.
    • High concentrations form in the presence of volatile organic compounds (VOCs) or during days with high solar radiation.
  • Total Suspended Particulates (TSP):
    • Solid matter or liquid droplets from smoke, dust, fuel ash, or condensing vapours.
    • From natural sources (sea, soil) or man-made sources (diesel exhausts, construction, factories).
    • Larger particulates filtered by the upper respiratory tract; smaller particulates enter deeper into the lungs.

7. Outdoor and Indoor Air Pollution

  • Outdoor Air Pollution:
    • Industrialisation.
    • Urbanisation.
  • Indoor Air Pollution:
    • Radon (Rn).
    • Environmental Tobacco Smoke (ETS).
    • Volatile Organic Compounds (VOC).
    • Biological Contaminants.
    • Carbon Dioxide (CO2).
    • Carbon Monoxide (CO).

8. Specific Indoor Air Pollutants

  • Radon (Rn):
    • Emitted from granite in concrete.
    • Prolonged exposure increases the risk of lung cancer, especially with tobacco smoke.
  • Environmental Tobacco Smoke (ETS):
    • Prolonged exposure causes lung cancer.
    • Short-term exposure results in irritation and respiratory problems.
    • Significantly increases the risk of lung cancer and heart diseases in non-smokers.
  • Volatile Organic Compounds (VOC):
    • Emitted from construction materials, furnishings, cosmetics, cleaning agents, pesticides, tobacco smoke, and dry-cleaned clothes.
    • Causes eye, nose, and throat irritations, headaches, dizziness, visual disorders, and central nervous system depression.
  • Biological Contaminants:
    • Examples: bacteria, fungi, viruses, and dust mites.
    • Symptoms: sneezing, watery eyes, coughing, shortness of breath, dizziness, lethargy, fever, and digestive problems.
  • Carbon Dioxide (CO2):
    • Living things breathe it out.
    • High levels indoors make occupants feel sleepy.
  • Carbon Monoxide (CO):
    • Generated from internal combustion engines or burning in deficient oxygen.
    • High levels can cause death within minutes.

9. Effects of Air Pollution on the Environment

  • Smog visibly worsened with higher air pollution indices in big cities.
  • Air pollutants trapped between tall buildings.
  • Greenhouse effect.
  • Depletion of the Ozone Layer.
  • Acid rain damage.

10. Controlling Outdoor Air Pollution

  • Air Pollution Index (API).
  • Air Quality Health Index (AQHI).
  • Government Policies.

11. Air Pollution Index (API)

  • Hourly API informs citizens about air quality.
  • Converts air pollution data into a value ranging from 0 to 500 in Hong Kong.
  • Helps the public take precautionary measures.

12. Air Quality Health Index (AQHI)

  • Replaced the Air Pollution Index (API) from December 30, 2013.
  • Provides timely and useful air pollution information.
  • Informs citizens of short-term health risks.
  • Reported on a scale of 1 to 10+ grouped into five health risk categories.

13. Government Policies to Control Pollution

  • Comprehensive programme initiated in 2000.
  • Main strategies: tighter fuel and vehicle emission standards, cleaner alternatives to diesel, pollutant traps, strengthened vehicle emission inspections, better vehicle maintenance and eco-driving habits.

14. Controlling Indoor Air Pollution

  • Manage the sources.
  • Dilute/remove pollutants.

15. Managing Sources of Indoor Air Pollution

  • Quitting smoking or advising people not to smoke.
  • Promoting a non-smoking policy.
  • Keeping major sources of formaldehyde out of premises.
  • Providing adequate or separate ventilation.
  • Sealing cracks to reduce radon emission.
  • Controlling the timing of the use of paints, glues and varnishes in confined spaces..
  • Cleaning air conditioner filters regularly.

16. Diluting/Removing Indoor Air Pollutants

  • Ensuring supply air vents and return air ducts are not blocked.
  • Maintaining the mechanical ventilation and air conditioning (MVAC) system in good condition.
  • Placing heat-generating equipment away from MVAC sensors.

17. Water Pollution

  • Bacteria, nutrients, and pollutants can make swimmers sick, contaminate marine life, and give off bad smells.
  • Hong Kong is working to improve water quality.
  • Pollutants come from human, industrial, and livestock sources.
  • Unspoiled clean water is being retained.

18. Effects of Water Pollution on Health

  • Bacteria are a primary public health concern.
  • Toxic metals accumulate in sediments and poison marine life and seafood.

19. Effects of Water Pollution on the Environment

  • Solid wastes in water.
  • Organic material consumes oxygen.
  • Ammonia is toxic to fish.
  • Nitrogen causes excessive algae growth and red tides.
  • Residual pollution in harbours, beaches, rivers, and streams is difficult to remove.

20. Controlling Water Pollution

  • Indicator: Coliform - a reliable indicator of the safety for human consumption if treatment includes chemical coagulation and filtration.

21. Sewage Treatment

  • Controlling pollution at the source.
  • Providing sewers.
  • Collecting and treating sewage.

22. Controlling Water Pollution at Source

  • The EPD controls waste water discharges through the Water Pollution Control Ordinance.
  • Operators must ensure discharges meet EPD standards through licences.
  • The EPD inspects operators, responds to complaints, and prosecutes offenders.

23. Providing Sewers

  • Ensuring everyone is connected to a sewer or a septic tank system in remote areas.
  • The department prepares sewerage masterplans, and the Drainage Services Department carries out the work.
  • Septic tank systems explained.

24. Collecting and Treating Sewage

  • Harbour Area Treatment Scheme (HATS) is a strategy for collecting and treating sewage from around Victoria Harbour.
  • Collection and treatment system in Tolo Harbour has resulted in a drop in red tides.

25. Long-term Measures for Water Treatment:

  • If the sewage could be treated to tertiary standard using the Biological Aerated Filters (BAF) technology, it can be discharged permanently into the Harbour .

26. Improving Water Quality at Beaches:

  • The EPD has made an enormous effort over the last decade to improve the water quality dramatically at beaches.
    • Rivers and streams are becoming cleaner as a result of livestock waste controls and a programme to connect villages to sewers.

27. Noise Pollution in Hong Kong

  • Poor planning in the past.
  • Cramped development.
  • Growth in the economy during the 1980s and 90s, which brought more construction and more traffic.

28. Noise Definitions

  • Loudness.
  • NC curves.
  • Noise Rating Curves.
  • Sound Level Weighting Scales.

29. Loudness

  • Subjective effect that is a function of the ear and brain as well as amplitude and frequency of the vibration.
  • Pure tones of different frequencies are compared with that of 1000 Hz by adjusting the amplitude to obtain equal-loudness contours.

30. NC curves

  • Used to specify the maximum speech interference level
  • The difference between loudness level and the speech interference level is equal to 22.

31. Noise Rating Curves

  • Used for the assessment of the acceptability of a noise to ensure preservation of hearing, speech communication, and to avoid annoyance.

32. Sound Level Weighting Scales

  • dB(A) – corresponds most closely to the response of the ear.
  • dB(B) – corresponds similarly to the 70-phon contour.
  • dB(C) – gives uniform flat response.
  • dB(D) – possesses a specialised characteristic, being the proposed standard for aircraft noise measurements.

33. Effects of Noise Pollution on Health

  • Above certain levels, noise can lead to hearing loss, mental stress, and irritation.
  • It can also interfere with daily activities.
  • It can have an enormous impact on the daily lives of people who are trapped in their flats.

34. Effects of Noise Pollution on the Environment

  • The source is existing roads which take heavy, noisy vehicles through cramped residential areas.
  • High-speed roads pass within a few metres of people's living rooms.
  • Urban streets lined with