Air%20Pollution

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Air Pollution
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Outline

• Classification
• Composition of air
• Sources of air pollution
• Effects
• Controls
• Major air pollution problems
• Air policy and Legislation
• Air Pollution Index (API)

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Types of air pollution

• Personal air pollution
• Occupational pollution
• Community / environmental air pollution

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Sources

• Natural
• Man-made

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Natural

• Wind-blow dust
• Smoke
• Gases from swamp
• Fog
• volcanic

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Natural Pollutants

• SO2
• H2S
• CO
• NO,NO2
• NH3
• Hydrocarbon
• CH4
• CO2
• O3

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Man-made

• Dust
• Combustion
• Manufacturing
• Agricultural
• Nuclear energy

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Man-made Pollutants

• Particulates
• Oxides of sulphur and nitrogen
• CO2
• Organic vapour
• Vapour with traces of heavy metal
• H2S
• Radioactive

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Effects

• Vegetation
• Human beings and animals
• Materials
• Health

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Materials

• Abrasion
• Deposition
• Chemical attack
• Corrosion

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Health

• Particulates respiratory tracts
• SO2 respiratory, asthematic
• CO2, CO -
• No2 - respiratory
• O3 - respiratory
• Pb nervous and cardiovascular

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Control

• Zoning
• Control at source
• Use device and equipment
• Use high stacks
• vegetation

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Zoning
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Control at source

• Replace
• Reengineering
• Redesign
• Reduce

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By device

• Gravitational settling chamber
• Inertial collectors
• Wet collectors
• Fabric
• Electrostatic precipitators

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Control at construction site

• Legislation
• Dust reduction measures
• Stop malpractice
• Notify Environmental Protection Dept

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Dust reduction measures

• Wet by water spray
• Provide hoarding to fence off the site
• Product dust screen
• Cover dusty materials on site and vehicles
• Dispose dusty materials correctly
• Cover unfinished site formation work
• Provide vehicle wash basin

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Stop malpractice

• Do not use compress air for cleaning
• Do not operate without any controls
• Do not stockpile dusty materials without proper
  procedures
• Do not blast on strong wind signals

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Notify EPD

• Site formation
• Reclamation
• Building demolition
• Tunnel work
• Building construction
• Road construction

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Major Problems

• Acid Rain
• Ozone depletion
• Green House Effect
• Indoor Air Pollution

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Acid Rain

• pH as low as 3
• Mainly due to Industrial pollutants
• No2, So2 and volatile organic vapour are
  converted to acidic compounds

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Effects of Acid Rain

• Natural life
• Building materials
• Crops and vegetation
• Cause deteriation of soil

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Ozone depletion

• Ozone exist in stratosphere (outer atmosphere)
• Ozone is used to shield ultra-violet light
  (short-wave length)
• Ozone is depleted by CFC (carbo-halogen-compound)
• Nitrous oxide contribute to depletion of ozone

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Effects of Ozone depletion

• Skin cancer
• Eye sickness
• Kill phytoplankton
• Decrease in food supplies
• More CO2

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Green House Effects

• Absorb long-wave (ultra-red)
• Let in short-wave and absorb long wave
• Acts like a glass in a green house
• Cause global warmness

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Effects of Green house

• Rise of water temperature and causing global
  climate changes

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Indoor Air Pollution

• CO
• Formaldehyde
• Radon
• NO2

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Effects of indoor air quality

• Sick building syndrome

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Control
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Control

• Land use planning
• Enforcement of Air Pollution Ordinance
• AQO
• Restrict certain specified process/trades

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Hong Kong Air Quality Objective

• SO2
• TSP
• RSP
• NO2
• CO
• Ozone
• Lead

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AQO

• Exposure in hours
• Exposure quantity

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Air Pollution Index
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What is API ?

• The API is an index that converts several
  pollutants into a value ranging from 0 500
• API forecast serves as a warning to the public

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How is it determined

• It is calculated by comparing the measured
  concentration of major air pollutants with their
  respective health related AQO.
• These pollutants are NO2, SO2, ozone, CO, and
  RSP.
• APIs for each of these pollutants are calculated
  and the highest API number is reported.
• APIs are reported hourly.

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How to use APIs ?

• The API values are divided into 5 bands.
• We can relate API to the followings
• Air Quality status
• Air Pollution level
• Health implication
• Actions recommended

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Locations of monitoring
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Roadside API
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