Air and Air Pollution

1
Air and Air Pollution
G. Tyler Miller, Jr.s Environmental Science 10th
Edition Chapter 12
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Key Concepts- Chapter Overview

• 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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When is a Lichen Like a Canary?

• Mine canaries

• Lichens

• Detectors of air pollution

• Lake Superior

• Chernobyl

Fig. 12-1, p. 255
4
Earths Atmosphere

• Troposphere

• 78 N, 21 O

• Stratosphere

• Ozone layer

Fig. 12-2 p. 256
5
Average Distribution and Concentration of Ozone
6
Beneficial vs. Harmful Ozone

• Located in Stratosphere
• Global Sunscreen
• Blocks 95 of suns UV
• Protection from sunburn, skin eye cancer,
  cataracts, immune system damage
• Prevents formation of photochemical ozone in
  troposphere
• ozone hole created by human activities

• Located in Troposphere
• Secondary pollutant- photochemical ozone
• Damages plants, lung tissue, materials
• Major component of photochemical smog

7
Outdoor Air Pollution

• Primary pollutants

• Secondary pollutants

Primary Pollutants
CO
CO2
Secondary Pollutants
SO2
NO
NO2
SO3
Most hydrocarbons
HNO3
H2SO4
Most suspended particles
H2O2
O3
PANs
Most
and
salts
Natural
Sources
Stationary
Mobile
Fig. 12-4, p. 258
Fig. 12-4 p. 258
Also refer to Tables 12-1 p. 258 and 12-2 p. 259
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Photochemical Smog

• Photochemical
• reactions

Fig. 12-5, p. 260

• Photochemicalsmog

• Brown-air smog

• Common in Cities with sunny, warm, dry
  climateswith lots of vehicles- L.A., Denver,
  Salt Lake,..

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Photochemical Smog
Clear day
Smoggy day
Fig. 12-6b, p. 261
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Industrial Smog

• Gray-air smog

• Sulfur dioxide- from coal

• Aerosols- suspended
• particles droplets

• Sulfuric acid

• No longer a problem in most MDCs

Fig. 12-7, p. 261
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Factors Influencing Smog Formation

• Local climate- rain,snow salt spray and winds
  cleanse air

• Topography- hills reduce air flow

• Types and amount of air pollutants

• Urban buildings- slow wind speed

• High temperatures- promote chemical rxns

12
How Nature Removes Air Pollution

• Precipitation

• Sea spray

• Wind

13
Temperature Inversions

• Radiation temperature inversion

Fig. 12-8a, p.263
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Temperature Inversions

• Subsidence temperature inversion

15
Regional Outdoor Air Pollution from Acid
Deposition (Acid Rain)

• Acid deposition

• Dry acid deposition

• Wet acid deposition

Fig. 20-8 p. 444
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Acid Deposition in the US

• In Eastern US most precipitation has pH of 4.2 -
  4.7 (10X higher than normal- 5.6)
• Some forests in E. US and near L.A. bathed in fog
  and dews as acidic as lemon juice (2.3)

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Areas Affected and Threatened by Acid Deposition
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Acid Deposition and Humans

• Respiratory diseases

• Toxic metal leaching

• Damage to structures and property

• Decreased visibility

• Decreased productivity and profitability of
  fisheries, forests, and farms

• Damage to scenic tourist areas

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Acid Deposition and Aquatic Systems

• Declines in fish populations-

• Loss of all fish below pH 4.5

• Aluminum toxicity- suffocates fish by clogging
  gills

• Acid shock- sudden runoff after snow melt

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Sensitivity of Aquatic Organisms to Acidic
Conditions
4.0
Water boatman
Whirligig
Yellow perch
Lake trout
Brown trout
Salamander (embryonic)
Mayfly
Smallmouth bass
Mussel
6.5
6.0
5.5
5.0
4.5
4.0
3.5
Fig. 12-11, p. 266
pH
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Effects of Acid Deposition on Plants and Soils

• Direct damage

• Nutrient leaching

• Metal release

• Moss growth

• Weakens trees

• Mountain trees

Fig. 12-12, p. 267
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Solutions to Acid Deposition
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Sick Building Syndrome

• Pollutants found in buildings linked to
  dizziness, headaches, coughing, sneezing, nausea,
  burning eyes, chronic fatigue and flu-like
  symptoms
• New buildings more commonly sick
• 17 of commercial buildings in US considered sick

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4 Most Dangerous Indoor Air Pollutants

• Formaldehyde
• Radioactive radon-222
• Cigarette smoke
• Ultrafine particles

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Indoor Air Pollution
Fig. 12-14, p. 269
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Indoor Air Pollutants
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Radon

• Radioactive radon-222

• Lung cancer threat

• Occurs in certain areas based on geology

• Associated with uranium in rocks
• and soils

Fig. 12-15, p. 270
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Effects of Air Pollution on People

• Respiratory diseases (see Fig. 12-17, p. 272)

• Asthma

• Lung cancer

• Chronic bronchitis

• Emphysema

• Premature death

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Solutions Preventing and Reducing Air Pollution

• U.S. Clean Air Acts

• U.S. National Ambient Air Quality Standards
  (NAAQS)

• Further possible improvements

• Emissions trading

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Emissions Reduction
Fig. 12-18, p. 275
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Motor Vehicle Air Pollution
Prevention
Cleanup
Mass transit
Emission control devices
Bicycles and walking
Less polluting engines
Less polluting fuels
Car exhaust Inspections twice a year
Improve fuel efficiency
Get older, polluting cars off the road
Give buyers tax write-offs for buying
low-polluting, energy-efficient vehicles
Restrict driving in polluted areas
Stricter emission standards
Fig. 12-20, p. 276
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Reducing IndoorAir Pollution
Fig. 12-21, p. 277
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Ways for Us to Prevent Air Pollution
Fig. 12-22, p. 278