Air and Air Pollution

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Air and Air Pollution
G. Tyler Millers Living in the Environment 13th
Edition Chapter 17
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Key Concepts

• Structure and composition of the atmosphere

• Types and sources of outdoor air pollution

• Types, formation, and effects of smog

• Sources and effects of acid deposition

• Effects of air pollution

• Prevention and control of air pollution

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The Atmosphere

• Stratosphere
• 11-30 miles
• Little water vapor
• Ozone layer
• UV filter
• Troposphere
• 11 mile at equator
• 8 miles at poles
• weather breeder
• 78 N, 21 O
• Natural heating
• Solar radiation
• Greenhouse effect

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The Atmosphere

• Exosphere
• Thermosphere
• ionosphere
• aurorea borialis
• hottest layer
• 1000 C
• Mesosphere
• very little atmosphere
• coldest layer

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Atmospheric pressure (millibars)
0
200
400
600
800
1,000
120
75
110
65
Thermosphere
100
90
55
80
45
70
Mesosphere
60
Altitude (miles)
Altitude (kilometers)
35
50
Heating via ozone
40
25
Stratosphere
30
15
Ozone layer
20
Heating from the earth
Troposphere
10
5
Pressure 1,000 millibars at ground level
0
80
40
0
40
80
120
(Sea Level)
Temperature (C)
6
40
25
35
20
Stratosphere
30
Benefical Ozone
25
Stratospheric ozone
15
Altitude (kilometers)
Altitude (miles)
20
10
15
10
5
Troposphere
Harmful Ozone
5
0
0
0
5
10
15
20
Ozone concentration (ppm)
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Air Pollution -

• the presence of one or more chemicals in the
  atmosphere in sufficient quantities and duration
  to (1) cause harm to us, other forms of life, and
  materials, or (2) alter climate.

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Major Classes of Air Pollutants

• Photochemical Oxidants
• Ozone, peroxyacal nitrates (PAN), hydrogen
  peroxide (H2O2)
• Suspended particulate matter (SPM)
• Dust, soot, asbestos, lead, nitrate, and sulfate
  salts
• Sulfuric acid, PCBs, dioxins, pesticides
• Radioactive substances
• Radon-222, iodine-131, strontium-90,
  plutonium-239
• Hazardous Air Pollutants (HAPS)

• Carbon oxides
• Carbon monoxide and carbon dioxide
• Sulfur oxides
• Sulfur dioxide and sulfur trioxide
• Nitrogen Oxides
• Nitric oxide, nitrogen dioxide, nitrous oxide
• Volatile Organic Compounds
• Methane, propane, CFCs

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Outdoor Air Pollution

• Primary pollutants
• pollutants emitted directly into the troposphere
  in a potentially harmful form.

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Outdoor Air Pollution

• Secondary pollutants
• Harmful chemical formed when primary pollutants
  react with one another or with the basic
  components of air.

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Criteria Air Pollutants

• Identified by the Clean Air Act 1970
• Carbon monoxide (CO)
• Nitrogen Dioxide (NO2)
• Sulfur Dioxide (SO2)
• Suspended Particulate Matter (SPM)
• Ozone (O3)
• Photochemical Oxidants
• Lead
• (Hydrocarbons)

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Atmospheric pressure (millibars)
0
200
400
600
800
1,000
120
75
110
65
Thermosphere
100
90
55
80
45
70
Mesosphere
60
Altitude (miles)
Altitude (kilometers)
35
50
40
25
Heating via ozone
Stratosphere
30
15
Ozone layer
20
Heating from the earth
Troposphere
10
5
Pressure 1,000 millibars at ground level
0
80
40
0
40
80
120
(Sea Level)
Temperature (C)
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Photochemical Reaction

• any chemical reaction activated by light

• Photochemical Smog
• a mixture of primary and secondary pollutants
  formed under the influence of sunlight
• Brown Air Smog
• (N2 O2 2NO) high temps
• (2NO O2 2NO2)
• NO2 (yellowish brown gas)

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Photochemical Smog

• Photochemicaloxidants
• NO2
• O3
• PANs
• react with and oxidize certain compounds in the
  atmosphere

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Industrial Smog

• Gray Smog
• Comes from burning coal
• Sulfur Dioxide
• Sulfuric Acid
• Particulates
• Unburned Carbon

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Temperature Inversions

• Subsidence inversion

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Temperature Inversions

• Radiation inversion

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Regional Outdoor Air Pollutionfrom Acid
Deposition

• Acid Deposition
• Falling of acids and acid forming compounds from
  the atmosphere
• H2SO4, HNO3

• Wet deposition
• Acid rain
• Dry deposition
• Acid particles

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Acid Deposition in the US
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Acid Deposition and Humans

• Respiratory diseases
• Toxic metal leaching into drinking water
• Decreased atmospheric visibility
• Damage to structures, especially containing
  limestone
• Decreased productivity and profitability of
  fisheries, forests, and farms

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Acid Deposition and Aquatic Systems

• Fish declines
• pH lt4.5
• Undesirable species
• Aluminum toxicity
• Acid Shock
• Sudden runoff

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Acid Deposition, Plants, and Soil

• Nutrient leaching

• Heavy metal release

• Weakens trees

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Indoor Air PollutionSick Building Syndrome
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Most dangerous indoor pollutants

1. Cigarette smoke
2. Formaldehyde
3. Radon-222 gas

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Radon

• Radon-222
• Associated with uranium (U-238) and organic
  material in rocks
• 2nd leading cause of lung cancer
• 4 picocuries
• EPA proposed standard

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Reducing IndoorAir Pollution
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Effects of Air Pollution on Living Organisms and
Materials

• Damage to mucous membranes

• Respiratory diseases
• Lung cancer
• Asthma allergic reaction
• Chronic bronchitis persistent inflammation
• Emphysema irreversible damage

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Effects of Air Pollution on Living Organisms and
Materials

• Damage to plant leaves and roots

• Reduction in primary productivity

• Deterioration of materials (See Table 17-3 p. 440)

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Emission Reduction
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Wet Scrubber
Cleaned gas
Dirty gas
Clean water
Electrostatic Precipitator
Wet gas
Dirty water
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Solutions Preventing and Reducing Air Pollution

• Clean Air Acts
• 1970, 1977, 1990
• National Ambient Air Quality Standards (NAAQS)
• Six outdoor criteria pollutants
• EPA regulates chemicals by using criteria from
  risk assessment methods
• Sets maximum permissible levels
• Primary Standard human health
• Secondary Standard environmental and property
  damage

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Can US Air Pollution Laws Be Improved?

• Continue to rely mostly on pollution cleanup
  rather than prevention.
• Fail to increase fuel-efficiency standards for
  cars and light trucks.
• Not adequately regulating emissions from
  inefficient two-cycle gasoline engines.
• Do little to reduce emissions of carbon dioxide
  and other greenhouse gases.

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The Next Steps

• Integrating government policies for energy and
  air pollution.
• Improving energy efficiency.
• Relying more on lower-polluting and more
  climate-benign natural gas.
• Increasing use of renewable energy.
• Regulating the air quality for an entire region
  or airshed with primary emphasis on prevention.