Chapter 16: Air Pollution
Chapter 15.1: Identify Natural and Human Caused Sources of Air Pollution
1) The Clean Air Act Designates Priority Pollutants
a. Natural sources of air Quality degradation
i. Volcanoes: ash, acid mist, hydrogen, sulfide and other toxics
ii. Sea Spray & Vegetation: major source of reactive sulfur compounds in air
iii. Trees & Bushes: emit millions of tons of volatile organic compounds
iv. Bacterial Metabolism: decaying vegetation in swamps and cellulose in
guts of termites/ animal causes two thirds of methane in air
b. Anthropogenic of air Quality concerns
i. Asthma
ii. Allergies
iii. Heart & Lung aliments
iv. Climate impacts
2) Criteria Pollutants were Addressed First

Clean air act in 1970nset new standards of 6 major pollutants

Ambient Air: air around us

Conventional/ Criteria Pollutants: Largest volume of air quality degradation and most
harmful to human wealth/ welfare

Primary Pollutants: Released directly from source

Secondary Pollutants: Convert to hazardous form of chemical reactions as stuff mix in air
a. Sulfur Dioxide
i. Natural sources of sulfur:
1. Evaporation of sea spray
2. Dust from arid soils
3. Fumes from volcanoes/ hot springs
ii. Anthropogenic Sulfur:
iii. Sulfur Dioxide: Combustion of fuel (coal & oil) purification of natural
gas/oil and smelting of sulfur oxides
iv. China & U.S major source of Sulfur dioxide
v. 114 million metric tons of sulfur worldwide
b. Nitrogen Oxides
i. Nitrogen oxides: Highly reactive gases formed when nitrogen in fuel/ air
is heated to temperature above 650 degrees Celsius in presence of oxygen
ii. Initial Product, nitric oxide, oxidizes further into atmosphere to nitrogen
dioxide
iii. Nitrogen Dioxide: Reddish brown gas that gives photochemical smog its
color
iv. Nitrous Oxide: intermediate form that results from soil densification
1. Absorbs ultraviolet light
v. Nitrogen oxides combines with water to make nitric acid a major
component of acid rain
vi. Nitrogen oxides in the U.S is produced by transportation and electric
power generation
c. Carbon monoxide
i. Carbon monoxide: colorless, odorless, nonirritating, but highly toxic gas
1. Produced mainly by incomplete combustion fuel as in furnace
incinerates, or fires
2. Blocks oxygen uptake in blood
ii. Anthropogenic of carbon monoxide is 1 billion metric tons
iii.
90% of carbon monoxide is converted to carbon dioxide
d. Ozone and Photochemical Oxidants
i. Ozone: high in stratosphere provides shield for the biosphere by absorbing
ultra violet radiation
1. On ground level damages vegetation building materials and
sensitive tissues
ii. Photochemical oxidants: reactions by sunlight between pollutants, such as
nitrogen oxides or volatile organic compound, or ozone
iii. Volatile organic compounds: term for organic chemicals that evaporate
easily or exists as gases in the air
1. Plants are largest source
2. Oxidized to and in the atmosphere
3. Methane produced by natural wetlands and rich patties and in guts
of termites/animals
e. Lead
i. Toxic to our nervous system and other critical functions
ii. Produced by industrial and mining processes
1. Main source: smelting, mining , and burning of coal/gasoline
iii. 2 million metric tons per year or 2/3 if metallic air pollution
f. Particle Matter
i. Particle matter: solid particles or liquid droplets suspended in a gaseous
medium
1. Aerosols: solid or liquid particles suspended in the atmosphere
a. Example: dust, ash, root, lint, smoke, etc…..
2. Soil conservations reduce PM10 and better management of dust
construction sites
3. Cause heart and lung diseases, allergies, asthma
3) Mercury, from Coal, Is Dangerous
a. 70% of airborne mercury derives from coal, smelting, and other industrial
combustion
b. 75% of mercury exposed to humans caused by fish
i. Aquatic bacteria converts airborne mercury into methyl mercury (mercury
in animal tissue)
ii. Causes neurological disabilities, deafness, blindness, loss of muscle
control and dementia
c. National Institute of Health (NIH) elevated mercury levels cost the U.S 8.7 billion
each year
d. Decreased due to the clean air act
4) Carbon Dioxide and Halogens are Key Greenhouse Gases
a. Carbon Dioxide production needed for economic productivity, therefore difficult
to limit
b. EPA regulates 6 green house gases:
i. Carbon dioxide, methane, nitrous oxide, hydroflouropcarbons,
perflourocarbons, and sulfur hexafluoride
c. Halogens: light weight, reactive elements
i.
Trap more energy in per molecule than ro2 and stat in the atmosphere for
centuries hazardous air pollutants can cause cancer and nerve damage
d. Chloroflourocarbons Carbon (CFC’S): diffuse in stratosphere, releasing chlorine
and fluorine, destroy ozone molecules
5) Hazardous Air Pollutants (HAPs) can Cause Cancer & Nerve Damage
i. Hazardous Air Pollutants (HAPs): remain in out ecosystem for long
periods and accumulate humans and animal tissue
ii. Toxic Release Inventory (TRI): collected by EPA as part of community
right to know
1. Most understand information of toxic pollution
6) Aesthetic Degradation also Results from Pollution
a. Aesthetic degradation: change in physical characteristics or chemistry of the
atmosphere such as noise, odors, and light pollution
i. Impact quality of life
ii. Light pollution is a concern in urban areas, where ambient light confuses
birds and hides the stars
7) Indoor Air can be Worse Than Outdoor Air
a. Finding less toxic paints/ fabrics can make indoor spaces healthier
i. Open fires/ unventiled stoves is bad
Chapter 16.2: Atmospheric Process
1) Temperatures Inversions Trap Pollutants
a. Temperature Inversions: Concentrate air pollutants
i. Inversions occur when warm air lies above cooler air, prevent convection
currents from dispersing pollutants
1. Mainly at nighttime
a. Example: Los Angeles
2) Wind Currents Carry Pollutants Worldwide
a. Process called “Grasshopper” transport, help contaminates to the poles
i. Air pollutants evaporate from warmer areas and then condense and
precipitate on cooler regions such as Arctic and Antarctica
b. Secondary air pollutants can be formed by photochemical reactions far from
primary emission sources
3) Stratospheric Ozone is Destroyed by Chlorine
a. Stratospheric Ozone: Concentrations over the South Pole were dropping as the
sun reappeared at the end of winter
i. Ozone depletion Pollutants: CFC’s & Halo gases
b. Ozone “Hole”: Reduced concentrations of ozone in stratosphere
4) The Montreal Protocol is a Resounding Success
a. Montreal Protocol: Phase out CFC’s
i.
HCFC’s replace CFC’s because they release chlorine per molecule
b. Cut CFC’s production by 95% since 1988
c. Stratospheric ozone, back to normal by 2049 due to Montreal
i. Climate Warming in atmosphere causes cooling stratosphere, this increase
ozone depletion
Chapter 16.3: Effects of Air Pollution
1) Polluted Air Damages Lungs
a. Greatest air problem is in poor ventilated homes in poorer countries
i. 2 million children under 5 years old die each year due to respirator
diseases
b. PM2.5 = heart attacks, asthma, bronchitis, lung cancer, immune suppression,
etc…
i. Power plants largest source
ii. Diesel engines cause soot and fine particle matter
c. 160 million Americans live in unhealthy air
2) How does Pollution make us Sick?
a. Sulfur Dioxide, Nitrogen Oxides, and Ozone act as irritants that damage delicate
tissues in eyes and respiratory passages
b. Fine particle irritants by penetrating deep into lungs and carry metals and other
HAP’s
i. Inflammatory is caused by irritants impairing lung function and a=heart
problems by the heart working harder to pump oxygen
c. Carbon monoxide and lead bines to hemoglobin reducing oxygen carrying
capacity at high levels
i. Lead at lower levels causes critical long lasting damage to neurons in
brain
d. Bronchitis: inflammation of bronchi and bronchioles, cause mucus build up
e. Emphysema: chronic obstructive lung disease, airways constricted and alveoli
damage/ destroyed
i. Both are important health effects of HAP’s
3) Plants suffer Cell Damage and Loss Productivity
a. HAPs can be directly toxic to cells
i. Mottling occurs in plant (discoloration)
ii. Necrotic (dead) spots develop
iii. Death in plant
b. Synergistic Effect: Injury caused by exposure to 2 factors together is more than
the sum of exposure to each individual factor
4) Acid Deposition Damaged Ecosystems
a. Acid Precipitation: Deposition of wet acidic solutions or dry acidic particulates
from air
i. Robert Angus Smith coined the term
ii. Describe in pH
1. Normal unpolluted rain pH 5.6
b. Aquatic effects
i. Lakes and streams near vegetation are naturally acidic, so any more acid
deposition is bad
1. Too much acid = no support for fish or aquatic organisms
ii. pH levels at/below 5 kills:
1. baby fish, aquatic plants, insects, and invertebrates (fish food),
adult fish
iii. sulfates account for 2/3 of acid deposition
iv. Nitrates are the other 1/3
c. Forest Damage
i. Nearly all trees are losing needles and half are dead due to
1. Acid rain and fog
2. Other air pollutants
3. Woody Aldegid (Insect)
ii. Depletion of calcium and magnesium replace by hydrogen and aluminum
ions in soil is the main cause of plant mortality
d. Buildings and Monuments
i. Limestone and marble destroyed by atmospheric acid
ii. Council on environmental quality estimates 4.8 billion in economic losses
in architect damage and 5,2 billion in property losses
5) Smog and Haze Reduce Variability
a. Mining, smelters, and power plants are main culprits
b. Haze blob: eastern U.S. during summers cuts visibility by 80%
Chapter 16.4: Progress and Pollution Control

Pollutants can be captured after production or avoided

Clean air legislation has reduced carbon monoxide, Sulfur dioxide but not nitrogen
oxides
1) Pollutants can be captured after combustion
a. Particulate removal involves filtering air emissions
i. Electrostatic precipitators are commonly used in power plants, disposed by
being buried in landfills
b. Sulfur removal is important because sulfur oxides damage human health/
ecosystem viability
i. Switch to low sulfur coal content
1. Ex: clean fuels like coal by crush, wash, and gasify to remove
sulfur
2. Cause solid waste and water pollution instead of air
c. Nitrogen Oxide reduced by controlling flow of air and fuels
d. Hydrocarbon reduce by closed systems that prevent escape of fugitive gases
i. After burners are best method to destroy VOCs in industrial exhaust stacks
2) Fuel Switching and Fuel Cleaning cut Emissions
a. Switching to natural gas has increased with growing supplies and falling prices
for gas
3) Clean Air Legislation is Controversial but Effective
a. Disputes of responsibility, cost, and definitions of risk cause a bill to languish
b. “Grandfather” existing equipment: exempt almost closed down factories from
new pollution limits
i. Owners expand these factories in order not to follow pollution limits
ii. 35 years later grandfather plants grow strong and contribute most to smog
and acid rain