Air Pollution

1
Air Pollution

• Chapter 18

2
Core Case Study South Asias Massive Brown Cloud

• Asian Brown Cloud
• Causes
• clearing and burning forest for planting crops
• Burning of coal, diesel, and other fossil fuels
  in industries , vehicles and homes
• Chemical composition
• 1/3rd of it is dust, smoke, and ash
• Rest is acidic compounds, soot, toxic metals
  (mercury and lead), hundreds of organic compounds
  and fly ash
• Areas impacted
• much of India, Bangladesh, the industrial heart
  of China, the Open Sea east of this area
• Photosynthesis has been reduced by 7-10
• Acid in the haze fall to the surface and damage
  crops, trees, and aquatic life

3
The Asian Brown Cloud

• Air pollution connects the world
• On certain days
• 25 of particulate matter
• 77 of black carbon
• 33 of toxic mercury in the skies
• above LA can be traced to
• China
• Steps taken in China and India to
• reduce air pollution
• strict pollution controls standards for
  coal-burning industries
• shifting from coal to cleaner burning natural
  gas

4
Air Pollution in Shanghai, China, in 2004
5
18-1 The Atmosphere Consists of Several Layers

• Atmosphere varies in
• Density
• The air we breathe at sea level is denser than
  the air on top of the worlds highest mountains.
• Atmospheric pressure
• Decreases with altitude because they are fewer
  gas molecules at higher levels

6
Earths Atmosphere

• Compared to the size of the Earth (12000 km)
• The atmosphere is very thin (120 km)
• or
• (75 miles)

After Mt. Pinatubo eruption 1991
http//www.gsfc.nasa.gov/gsfc/earth/pinatuboimages
.htm
7
Atmospheric Layers

• The atmosphere consists of layers around the
  Earth, each one defined by the way temperature
  changes within its limits.
• The layer boundaries are
• Tropopause
• Stratopause
• Mesopause
• The outermost, the thermosphere, thins slowly,
  fading into space with no boundary.

8
Air Movements in the Troposphere Play a Key Role
in Earths Weather and Climate

• Troposphere
• This is where we live
• 8 to 14.5 kilometers high (5 to 9 miles)
• the temperature drops from about 17 to -52
  degrees Celsius
• 7580 of the earths air mass
• most dense
• Closet to the earth's surface
• Rising and falling air currents weather and
  climate
• Involved in chemical cycling

9
Composition

• Nitrogen (N2, 78)
• Oxygen (O2, 21)
• Argon (Ar, 1)
• myriad of other very
  influential components are also
  present which include the Water (H2O, 0 - 7),
  "greenhouse" gases or Ozone (O3, 0 - 0.01),
  Carbon Dioxide (CO2, 0.01-0.1),

10
The Stratosphere Is Our Global Sunscreen

• Stratosphere
• extends to 50 kilometers (31 miles) high
• dry and less dense
• temperature in this region increases gradually to
  -3 degrees Celsius, due to the absorption of
  ultraviolet radiation
• ozone layer absorbs and scatters the solar
  ultraviolet radiation
• ninety-nine percent of "air" is located in first
  two layers
• every 1000-m 11 less air pressure
• Similar composition to the troposphere, with 2
  exceptions
• Much less water
• O3, ozone layer, filters UV

11
Natural Capital The Earths Atmosphere Is a
Dynamic System with Four Layers
12
O3 -The Good, the Bad, and the Ugly
13
O3 -The Good
(15 - 40 km) blocks solar UV llt290 nm
Beneficial Ozone that forms in the stratosphere
protects life on earth by filtering out most of
the incoming harmful UV radiation emitted by the
sun
14
O3 -The Bad
6-10 km greenhouse gas absorbs IR emitted by
Earth
O3 ?O3 (v1)

• Harmful or Photochemical ozone forms in the
  troposphere when various air pollutants undergo
  chemical reactions under the influence of
  sunlight. Ozone in the atmosphere near the
  earths surface damages plants, lung tissue, and
  some materials such as rubber.
• It is a strong oxidant and respiratory irritant.
• Ground level ozone results primarily from
  motor-vehicle exhaust

15
O3 -The Ugly
part of smog (bad, too)
16
18-2 Air Pollution Comes from Natural and Human
Sources

• Air pollution
• The presence of chemicals in the atmosphere in
  concentrations high enough to harm organisms,
  ecosystems, or human-made material.
• Natural sources
• Dust blown by wind
• Pollutants from wildfires and volcanoes
• Volatile organics released by plants
• Withdrawing groundwater

17
Air Pollution Comes from Natural and Human
Sources

• Human sources mostly in industrialized and/or
  urban areas
• Stationary sources
• Mobile sources

18
Sources and Types of Air Pollutants
19
Primary Pollutants
Secondary Pollutants
CO
CO2
SO2
NO
NO2
SO3
Most hydrocarbons
HNO3
H2SO4
Most suspended particles
H2O2
O3
PANs
Most NO3- and SO42- salts
Sources
Natural
Stationary
Mobile
Fig. 18-4, p. 472
20
Case Study Air Pollution in the Past The Bad
Old Days

• Discovery of fire
• Middle Ages
• 1700s - Industrial Revolution
• London, England
• 1850s dense mixture of coal smoke and fog
• 1880- a prolonged coal fog killed an estimated
  2,200 people
• 1952 yellow fog lasted for 5 days and killed
  4,000- 12,000 Londoners
• Clean Air Act of 1956

21
Case Study Air Pollution in the Past The Bad
Old Days (2)

• United States
• 1948 Donora, PA first U.S. air pollution
  disaster
• 1963 New York City
• Global problem
• Urban areas in China, India and parts of Eastern
  Europe that depend on coal in industries and in
  some homes face air pollution levels similar to
  those in London and America in the 1950s

22
Some Pollutants in the Atmosphere Combine to Form
Other Pollutants

• Primary pollutants
• Are harmful chemicals emitted directly into the
  air from natural processes and human activities.
• Secondary pollutants
• Primary pollutants react with one another and
  with the basic components of air to form new
  harmful chemicals
• Air quality improving in developed countries
• Much more needs to be done in developing
  countries
• Indoor pollution big threat to the poor

23
Indoor Air Pollution
24
What Are the Major Outdoor Air Pollutants?

• Carbon oxides
• Carbon monoxide (CO)
• Colorless and highly toxic that forms during the
  incomplete combustion of carbon-containing
  materials. Reacts with hemoglobin in blood cells
  reduces the ability to transport oxygen.
• Sources
• Motor vehicles exhaust, burning of forest and
  grasslands, tobacco smoke, and open fires and
  inefficient stoves used for cooking.
• Carbon dioxide (CO2)
• Colorless, odorless gas.
• 93 result of natural carbon cycle
• Rest from burning fossil fuels and clearing CO2
  absorbing forest and grasslands.
• Emissions have been rising since the industrial
  revolution

25
What Are the Major Outdoor Air Pollutants?

• Nitrogen oxides (NO) and nitric acid (HNO3)
• Sources- automobiles, coal-burning plants
• NO reacts with oxygen to form NO2 (reddish brown
  gas) NO and NO2 are collectively called NOx
• Acid deposition
• Photochemical smog
• Human health and environmental impact
• Nitrous oxide (N2O) a greenhouse gas that is
  emitted from fertilizers and animal waste and by
  burning fossil fuels

26
Major Outdoor Pollutants

• Sulfur dioxide (SO2) and sulfuric acid (H2SO4)
• Description Colorless, irritating forms mostly
  from the combustion of sulfur containing fossil
  fuels such as coal and oil (S O2 SO2) in the
  atmosphere
• can be converted to sulfuric acid (H2SO4), a
  major component of acid deposition.
• Major human sources Coal burning in power plants
  (88) and industrial processes
• (10).
• Health effects Breathing problems for healthy
  people restriction of airways in people with
  asthma chronic exposure can cause a permanent
  condition similar to bronchitis. According to the
  WHO, at least 625 million people are exposed to
  unsafe levels of sulfur dioxide from fossil fuel
  burning.
• Environmental effects Reduces visibility acid
  deposition of H2SO4 can damage trees, soils, and
  aquatic life in lakes.
• Property damage SO2 and H2SO4 can corrode metals
  and eat away stone on buildings, statues, and
  monuments SO2 can damage paint, paper, and
  leather.

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What Are the Major Outdoor Air Pollutants?

• Particulates
• Suspended particulate matter (SPM)
• Variety of particles and droplets (aerosols)
  small and light enough to remain suspended in
  atmosphere for short periods (large particles) to
  long periods
• cause smoke, dust, and haze.
• Sources
• Burning coal in power and industrial plants
  (40), burning diesel and other fuels in vehicles
  (17), agriculture (plowing, burning off fields),
  unpaved roads, construction.
• Human health and environmental impact
• Nose and throat irritation, lung damage, and
  bronchitis aggravates bronchitis and asthma
  shortens life toxic particulates (such as lead,
  cadmium, PCBs, and dioxins) can cause mutations,
  reproductive problems, cancer.
• Reduces visibility acid deposition of H2SO4
  droplets can
• damage trees, soils, and aquatic life in lakes

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What Are the Major Outdoor Air Pollutants?

• Ozone (O3)
• Highly reactive, irritating gas with an
  unpleasant odor that forms in the troposphere as
  a major component of photochemical smog
• Sources Chemical reaction with volatile organic
  compounds (VOCs, emitted mostly by cars and
  industries) and nitrogen oxides to form
  photochemical smog
• Human and environmental impact
• Breathing problems coughing eye, nose, and
  throat irritation aggravates chronic diseases
  such as asthma, bronchitis, emphysema, and heart
  disease reduces resistance to colds and
  pneumonia may speed up lung tissue aging.
• Environmental effects Ozone can damage plants
  and trees smog can reduce visibility.
• Property damage Damages rubber, fabrics, and
  paints.

30
What Are the Major Outdoor Air Pollutants?

• Volatile organic compounds (VOCs)
• organic compounds (hydrocarbons) that evaporate
  easily, usually aromatic
• Hydrocarbons and terpenes
• Sources
• Methane, chlorofluorocarbon, benzene and
  proprane.
• vehicles (largest source), evaporation of
  solvents or fossil fuels, aerosols, paint
  thinners, dry cleaning
• Human and environmental impact
• eye and respiratory irritants carcinogenic
  liver, CNS, or kidney damage damages plants
  lowered visibility due to brown haze global
  warming

31
Chemical Reactions That Form Major Outdoor Air
Pollutants
32
Statue Corroded by Acid Deposition and Other
Forms of Air Pollution, RI, U.S.
33
Natural Capital Lichen Species, Vulnerability
to Air Pollutants
Case Study When is a Lichen Like a Canary
34
Case Study Lead Is a Highly Toxic Pollutant

• Does not break down in the environment
• Solid toxic metal and its compounds, emitted into
  the atmosphere as particulate matter.
• Sources
• Paint old houses), smelters (metal refineries),
  lead manufacture, storage batteries, leaded
  gasoline (being phased out in developed
  countries).
• Human health and environmental impact
• Accumulates in the body brain and other nervous
  system damage and mental retardation (especially
  in children) digestive and other health
  problems some lead-containing chemicals cause
  cancer in test animals. Can harm wildlife.

35
Case Study Lead Is a Highly Toxic Pollutant

• Reduction of lead (Pb)
• Unleaded gasoline
• Unleaded paint 1960
• Still problems
• 2007 toys with Pb paint recalled
• 2007 2/3rd of red long-lasting lipstick
  manufactured in the US contained surprisingly
  high levels of lead.
• Global ban on lead in gasoline and paint

36
SOLUTIONS
Lead Poisoning
Prevention
Control
Replace lead pipes and plumbing fixtures
containing lead solder
Phase out leaded gasoline worldwide
Phase out waste incineration
Remove leaded paint and lead dust from older
houses and apartments
Ban use of lead solder
Sharply reduce lead emissions from incinerators
Ban use of lead in computer and TV monitors
Remove lead from TV sets and computer monitors
before incineration or land disposal
Ban lead glazing for ceramicware used to serve
food
Test for lead in existing ceramicware used to
serve food
Ban candles with lead cores
Test existing candles for lead
Test blood for lead by age 1
Wash fresh fruits and vegetables
Fig. 18-7, p. 476
37
Burning Coal Produces Industrial Smog

• Chemical composition of industrial smog
• mixture of SO2, droplets of sulfuric acid, and a
  variety of suspended solid particles emitted by
  burning coal
• Reduction of this smog in urban cities of the
  United States
• China and smog

38
How Pollutants Are Formed from Burning Coal and
Oil, Leading to Industrial Smog
39
Ammonium sulfate (NH4)2SO4
Ammonia (NH3)
Sulfuric acid (H2SO4)
Carbon monoxide (CO) and carbon dioxide (CO2)
Water vapor (H2O)
Sulfur trioxide (SO 3 )
Oxygen (O2)
Sulfur dioxide (SO2)
Burning coal and oil
Oxygen (O2)
Carbon (C) in coal and oil
Sulfur (S) in coal and oil
Fig. 18-8, p. 476
40
Stepped Art
Fig. 18-8, p. 476
41
Sunlight Plus Cars Equals Photochemical Smog

• Photochemical Smog
• Chemical composition
• is a mixture of air pollutants formed by the
  reaction of nitrogen oxides and volatile organic
  hydrocarbon compounds under the influence of
  light
• VOCs NO2 Heat Sunlight yields
• Ground level O3 and other photochemical oxidants
• Aldehydes
• Other secondary pollutants

42
A Model of How Pollutants That Make Up
Photochemicals Are Formed
43
PANS and other pollutants
Volatile organic compounds (VOCs)
Ozone (O3)
Oxygen (O2)
Nitric oxide (NO) Oxygen atom (O)
Water vapor (H2O)
Hydrocarbons
UV radiation
Peroxyacyl nitrates (PANs)
Nitrogen dioxide (NO2)
Oxygen (O2)
Nitric oxide (NO)
Oxygen (O2)
Burning fossil fuels
Nitrogen (N) in fossil fuel
Fig. 18-9, p. 477
44
Global Outlook Photochemical Smog in Santiago,
Chile
45
How can trees Contribute to Photochemical Smog?

• Trees certainly have environmental benefits
• Emit oxygen, absorb CO2, provide shade, and help
  absorb and remove various pollutants from the
  air.
• Some trees (some oak species, sweet gums,
  Poplars, and Kudzu) in and around urban areas
  play a large role in smog formation
• They emit VOCs (like isoprene) that are
  ingredients in the development of photochemical
  smog.
• Plants in urban areas should be trees that emit
  low levels of VOCs.

46
Several Factors Can Decrease or Increase Outdoor
Air Pollution

• Outdoor air pollution may be decreased by
• Settling of particles due to gravity
• Rain and snow
• Salty sea spray from the ocean
• Winds
• Chemical reactions

47
Several Factors Can Decrease or Increase Outdoor
Air Pollution

• Outdoor air pollution may be increased by
• Urban buildings
• Hills and mountains
• High temperatures
• Emissions of VOCs from certain trees and plants
• Grasshopper effect
• Temperature inversions

48
A Temperature Inversion
49
Descending warm air mass
Warmer air
Inversion layer
Inversion layer
Sea breeze
Increasing altitude
Decreasing temperature
Fig. 18-11, p. 478
50
Animation Formation of photochemical smog
51
Animation Thermal inversion and smog
52
18-3 Acid Disposition Is a Serious Regional Air
Pollution Problem

• Acid deposition, acid rain
• Local versus regional problems
• Tall smokestacks reduce local air pollution by
  increases region air pollution downwind
• Effects of prevailing winds
• Where is the worst acid deposition?

53
Acid Deposition Formation

• When gas pollutants e.g. carbon dioxide, sulfur
  dioxide, nitrogen dioxide dissolve in rain water,
  various acids are formed.

CO2 H2O ? H2CO3 (carbonic acid) SO2
H2O ? H2SO3 (sulfurous acid) NO2 H2O ? HNO2
(nitrous acid) HNO3 (nitric acid)
54
Causes of Acid Rain

• Sulfur dioxide (SO2) and nitrogen oxides (NOx)
  are the primary causes of acid rain.
• In the US, About 2/3 of all SO2and 1/4 of all
  NOx comes from electric power generation that
  relies on burning fossil fuels like coal.

55
Natural Capital Degradation Acid Deposition,
Acid Rain
56
pH measurements in relation to major coal-burning
andindustrial plants. (Normal rain has a pH of
5.6)
57
Current and Possible Future Acid Rain Problem
Areas
58
Potential problem areas because of sensitive soils
Potential problem areas because of air pollution
emissions leading to acid deposition
Current problem areas (including lakes and rivers)
Fig. 18-13, p. 480
59
Increased Acidity

• Dry deposited gases and particles can also be
  washed from trees and other surfaces by
  rainstorms.
• The runoff water adds those acids to the acid
  rain, making the combination more acidic than the
  falling rain alone.

60
Effects of Acid Rain

• Has a variety of effects, including damage to
  forests and soils, fish and other living things,
  materials, and human health.
• Also reduces how far and how clearly we can see
  through the air, an effect called visibility
  reduction.
• Effects of acid rain are most clearly seen in the
  aquatic environments
• Most lakes and streams have a pH between 6 and 8

http//cica.indiana.edu/projects/Biology/movies.ht
ml
61
Buffering Capacity

• Acid rain primarily affects sensitive bodies of
  water, which are located in watersheds whose
  soils have a limited buffering capacity
• Lakes and streams become acidic when the water
  itself and its surrounding soil cannot buffer the
  acid rain enough to neutralize it.

62

• In areas where buffering capacity is low, acid
  rain also releases aluminum ions from soils into
  lakes and streams aluminum is highly toxic to
  many species of aquatic organisms referred to as
  acid shock.

http//home.earthlink.net/photofish/fish_photos/s
w10_thumb.jpg
63
Effects on Wildlife

• Generally, the young of most species are more
  sensitive to environmental conditions than
  adults.
• At pH 5, most fish eggs cannot hatch.
• At lower pH levels, some adult fish die.
• Some acid lakes have no fish.

64
Acid Rain and Forests

• Acid rain does not usually kill trees directly.
• Instead, it is more likely to weaken trees by
  damaging their leaves, limiting the nutrients
  available to them, or exposing them to toxic
  substances slowly released from the soil.

65
Mongolia
Germany
66
Effects of Acid Rain
Great Smoky Mountains, NC
67
Nutrients

• Acidic water dissolves the nutrients and helpful
  minerals in the soil and then washes them away
  before trees and other plants can use them to
  grow.
• Acid rain also causes the release of substances
  that are toxic to trees and plants, such as
  aluminum, into the soil.

68
Acid Deposition Has a Number of Harmful Effects

• Human respiratory disorders
• Aquatic ecosystems affected
• Release of toxic metal
• Toxic lead and mercury
• Leaching of soil nutrients
• Loss of crops and trees
• Damage to buildings, statues, and monuments

69
Natural Capital Degradation Air Pollution Damage
to Trees in North Carolina, U.S.
70
Solutions Acid Deposition, Prevention and Cleanup
71
Active Figure Acid deposition
72
Video Air pollution in China
73
Active Figure Effect of air pollution in forests
74
18-4 Indoor Air Pollution Is a Serious Problem

• Developing countries
• Indoor burning of wood, charcoal, dung, crop
  residues, coal in open fires or unvented or
  poorly vented stoves
• Poor suffer the greatest risk
• Developed countries
• Indoor air pollution is greater than outdoor air
  pollution

75
Exposure

• Time spent in various environments in US and
  less-developed countries

76
Indoor Air Pollution Is a Serious Problem

• Why?
• 11 of the common air pollutants higher inside
  than outside
• Greater in vehicles than outside
• Health risks magnified people spend 7098 of
  their time is indoors

77
Indoor Air Pollution Is a Serious Problem

• Who are at greatest risk from indoor air
  pollution?
• Children under 5 and the elderly
• Sick
• Pregnant women
• People with respiratory disorders or heart
  problems
• Smokers
• Factory workers

78
Indoor Air Pollution Is a Serious Problem

• Four most dangerous indoor air pollutants
• Tobacco smoke- most preventable
• Formaldehyde
• Found in many building material, and household
  products (plywood, particle board, paneling,
  high-gloss wood, drapes, furniture, carpets,
  wallpaper, wrinkle- free coating on permanent
  press clothing)
• The chemical that causes most people in developed
  countries difficulty
• Colorless extremely irritating chemical
• Causes chronic breathing problems, dizziness,
  skin, eye, sinus irritation, rash, headaches,
  sore throats, wheezing and nausea
• EPA estimates that 1 of every 5,000 people who
  live in manufactured homes for more than 10 years
  will develop cancer from formaldehyde exposure.

79
Four most dangerous indoor air pollutants (cont)

• Radioactive radon-222 gas
• Seep into houses from underground rock deposits
• Colorless odorless radioactive gas produced by
  the natural decay of uranium-238.
• lung tissue damage, lung cancer
• Estimated that 7,000 to 30,000 Americans die each
  year from radon-induced lung cancer
• Only smoking causes more lung cancer deaths
• Smokers more at risk than non-smokers
• Very small particles
• Asbestos
• Irritate the nose and throat, damage the lungs,
  aggravate asthma and bronchitis, and shorten
  life.

80
Science Sources and Paths of Entry for Indoor
Radon-222 Gas
81
(From http//www.epa.gov/iaq/radon/zonemap.html)
Zone pCi/L 1 gt4 2 2 - 4
3 lt2
82
Indoor Air Pollution Is a Serious Problem

• Other possible indoor air pollutants
• Pesticide residue
• Pb particles
• Living organisms and their excrements
• E.g., Dust mites and cockroach droppings
• Airborne spores of molds and mildews

83
Science Magnified View of a Household Dust Mite
in a Dust Ball
84
Some Important Indoor Air Pollutants
85
Chloroform
Para-dichlorobenzene
Tetrachloroethylene
Source Chlorine-treated water in hot showers
Possible threat Cancer
Source Air fresheners, mothball crystals
Threat Cancer
Source Dry-cleaning fluid fumes on clothes
Threat Nerve disorders, damage to liver and
kidneys, possible cancer
Formaldehyde
Source Furniture stuffing, paneling,
particleboard, foam insulation Threat
Irritation of eyes, throat, skin, and lungs
nausea dizziness
1,1,1-Trichloroethane
Source Aerosol sprays Threat Dizziness,
irregular breathing
Styrene
Nitrogen oxides
Source Carpets, plastic products Threat Kidney
and liver damage
Source Unvented gas stoves and kerosene heaters,
woodstoves Threat Irritated lungs, children's
colds, headaches
Benzo- a -pyrene
Source Tobacco smoke, woodstoves Threat Lung
cancer
Particulates
Source Pollen, pet dander, dust mites, cooking
smoke particles Threat Irritated lungs, asthma
attacks, itchy eyes, runny nose, lung disease
Radon-222
Source Radioactive soil and rock surrounding
foundation, water supply Threat Lung cancer
Tobacco smoke
Source Cigarettes Threat Lung cancer,
respiratory ailments, heart disease
Asbestos
Carbon monoxide
Methylene chloride
Source Pipe insulation, vinyl ceiling and floor
tiles Threat Lung disease, lung cancer
Source Faulty furnaces, unvented gas stoves and
kerosene heaters, woodstoves Threat Headaches,
drowsiness, irregular heartbeat, death
Source Paint strippers and thinners Threat
Nerve disorders, diabetes
Fig. 18-16, p. 484
86

• Sick Building Syndrome (SBS)
• vs
• Building Related Illness (BRI)

87
Sick Building Syndrome

• A persistent set of symptoms in gt 20 population
• Causes(s) not known or recognizable
• Complaints/Symptoms relieved after exiting
  building
• Linked to inadequate ventilation, new buildings
  that contain chemicals such as formaldehyde from
  building products, or biological contaminants
  like mold or pollen.

88
Complaints/Symptoms

• Headaches
• Fatigue
• Reduced Mentation
• Irritability
• Eye, nose or throat irritation

• Dry Skin
• Nasal Congestion
• Difficulty Breathing
• Nose Bleeds
• Nausea

89
Building Related Illness

• Clinically Recognized Disease
• Exposure to indoor air pollutants
• Recognizable Causes

90
Clinically Recognized Diseases

• Pontiac Fever Legionella spp.
• Legionnaire's Disease
• Hypersensitivity Pneumonitis
• Humidifier Fever
• Asthma
• Allergy
• Respiratory Disease
• Chronic Obstructive Pulmonary Disease

91
18-5 Your Bodys Natural Defenses against Air
Pollution Can Be Overwhelmed

• Respiratory system protection from air pollutants
• Hair in nose, cilia, mucus, sneezing, and
  coughing
• Effect of smoking and prolonged air pollution
  exposure
• Chronic bronchitis
• Emphysema- irreversible damage to the air sacs in
  the lungs

92
Major Components of the Human Respiratory System
93
Normal Human Lungs and the Lungs of a Person Who
Died of Emphysema
94
Air Pollution Is a Big Killer

• 3 Million deaths per year world-wide
• Mostly in Asia
• Main causes
• Heart attacks, respiratory diseases, and lung
  cancer
• EPA proposed stricter emission standards for
  diesel-powered vehicles
• Link between international trade and air
  pollution
• Cargo ships and pollution

95
Premature Deaths from Air Pollution in the U.S.
96
18-6 Laws and Regulations Can Reduce Outdoor Air
Pollution (1)

• United States
• Clean Air Acts 1970, 1977, and 1990
• EPA
• National ambient air quality standards (NAAQs)
  for 6 outdoor criteria pollutants
• National emission standards for 188 hazardous air
  pollutants (HAPs)
• Toxic Release Inventory (TRI)

97
Clean Air Act

• Originally signed 1963
• States controlled standards
• 1970 Uniform Standards by Federal Govt.
• Criteria Pollutants
• Primary Human health risk
• Secondary Protect materials, crops, climate,
  visibility, personal comfort

98
Clean Air Act

• 1990 version
• Acid rain, urban smog, toxic air pollutants,
  ozone depletion, marketing pollution rights,
  VOCs
• 1997 version
• Reduced ambient ozone levels
• Cost 15 billion/year -gt save 15,000 lives
• Reduce bronchitis cases by 60,000 per year
• Reduce hospital respiratory admission 9000/year

99
PREVENTING AND REDUCINGAIR POLLUTION

• The Clean Air Acts in the United States have
• greatly reduced outdoor air pollution from
• six major pollutants
• Carbon monoxide
• Nitrogen oxides
• Sulfur dioxides
• Suspended particulate matter (less than PM-10)
• Tropospheric Ozone

100
Laws and Regulations Can Reduce Outdoor Air
Pollution (2)

• Good news in U.S.
• Decrease in emissions
• Use of low-sulfur diesel fuel
• Cuts pollution
• Developing countries
• More air pollution

101
Case Study U.S. Air Pollution Can Be Improved

• Rely on cleanup more than prevention of pollution
• Raise fuel-efficiency for cars, SUVs, and light
  trucks
• Better regulation of emissions of motorcycles and
  two-cycle gasoline engines
• Regulate air pollution for oceangoing ships in
  American ports

102
Case Study U.S. Air Pollution Can Be Improved
(2)

• Why are airports exempt from many regulations?
• Regulate greenhouse gas emissions
• Ultrafine particles are not regulated
• Urban O3 levels too high

103
Case Study U.S. Air Pollution Can Be Improved
(3)

• What about indoor air pollution?
• Better enforcement of the Clean Air Acts
• Intense pressure needed from citizens to make
  improvements

104
We Can Use the Marketplace to Reduce Outdoor Air
Pollution

• Emission trading or cap-and-trade program
• Mixed reactions to program
• SO2 emissions down significantly
• NO2 will be tried in the future

105
There Are Many Ways to Reduce Outdoor Air
Pollution

• 1980 2006
• SO2 emissions from U.S. electric power plants
  decreased by 66
• NOx emissions by 41
• Particulate emissions by 28
• Older plants not governed by the same regulations
• New cars have better emissions

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Solutions Stationary Source Air Pollution
107
Prevention of Air pollution
Post combustion method

• Catalytic converter to oxidize the sulfur to
  yield sulfur compounds.
• A lime scrubber in a smokestack may be used
• In a wet scrubber, a slurry of lime mixed w/
  water is sprayed across the exiting gases. The
  sulfur mixes w/ the calcium, forming the calcium
  sulfate, which falls to the bottom of the
  smokestack as bottom ash.
• Most particulates are removed post combustion

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Electrostatic Precipitator
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Cleaned gas
Dirty gas
Baghouse Filter
Dust discharge
110
Dirty gas
Cyclone Separator
Dust discharge
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Dirty gas
Clean water
Wet Scrubber
Dirty water
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Solutions Motor Vehicle Air Pollution,
Prevention and Cleanup
113
Reducing Indoor Air Pollution Should Be a
Priority

• Greater threat to human health than outdoor
  pollution
• What can be done?
• Prevention
• Cleanup

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Movement of Air Into / Out of Homes

• Amount of air available to dilute pollutants
• important indicator of the likely contaminant
  concentration
• Indoor air can mix with outside air by three
  mechanisms
• infiltration
• natural ventilation
• forced ventilation

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Movement of Air Into / Out of Homes

• Natural ventilation
• air exchange that occurs when windows or doors
  are opened to increase air circulation
• Forced ventilation
• mechanical air handling systems used to induce
  air exchange using fans and blowers
• Trade-offs
• cut infiltration to decrease heating and cooling
  costs vs. indoor air quality problems

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Solutions Indoor Pollution, Prevention and
Cleanup or Dilution
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What Can You Do? Indoor Pollution Ways to Reduce
Your Exposure
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Solutions Air Pollution, Ways to Prevent It Over
the Next 3040 Years
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ABC Video Clean Air Act