air pollution
TRANSCRIPT
What is Air Pollution?
• Some gases• Aerosols: microscopic liquid and solid
particles– Dust– Carbon– Pollen– Sea salts– microorganisms
Composition of the Atmosphere
Component Concentration (vol %)
Constant
Nitrogen, N2 78.08
Oxygen, O2 20.95
Argon, Ar 0.93
Neon, Ne 0.0018
Helium, He 0.0005
Hydrogen, H2 0.00005
Variable
Water, H2O 0 to 4
Carbon Dioxide, CO2 0.036
Methane, CH4 0.00017
Ozone, O3 0.000004
Carbon Monoxide, CO 0.000002
Other < 0.000002
What Factors Determine the Level of Air Pollution?
• Quantity of pollutants entering air
• Space into which pollutants disperse
• Removal of pollutants
Removal of Pollutants: Hydroxyl Radical
Two Kinds of Smog (smoke+fog)
• Industrial Smog:– Combination of smoke and fog– Depends on concentration of industry– Coal as primary energy/heating source– China, Korea, Eastern Europe– Combination of soot, sulfurous compounds,
water vapor
• Photochemical Smog:– Auto exhaust + sunlight– Starts in AM, dissipates in PM– LA, NYC, etc
Weather Conditions Can Make Smog Worse: Inversion
Air Pollution Disasters
• Donora, PA: Smog of 1948 – ½ town population sickened – 20 dead
• London: Great Smog of 1952 – 4000 dead
http://www.youtube.com/watch?v=3PO_3exwN-I