APES CH 15 NOTES
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Air Pollution
 Air pollution- the introduction of ______________________, particulate matter, or
microorganisms into the atmosphere at concentrations high enough to ____________ plants,
animals, and materials such as buildings, or to alter ecosystems.
 Sources can be ___________ such as volcanoes and fires or _____________________
like automobiles and factories.
 Air pollution doesn’t stay ________: Acid rain rainfall on the west coast of the US has
been caused by pollution in ___________.
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Major Air Pollutants
 CAA 1970 identified 6 pollutants that significantly threaten human well-being. Criteria air
pollutants.
 _________________ Dioxide
 Nitrogen Oxides
 Carbon ______________________ (dioxide listed in 2007. US supreme court rule)
 __________________ Matter
 Ozone
 __________________
 Other air pollutants
 Mercury and Volatiles Organic Compounds
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Primary Pollutants
 Primary pollutants- polluting compounds that come ___________________- out of the smokestack, exhaust pipe, or natural emission source.
 Examples: CO, CO2, SO2, NOx, and most suspended particulate matter.
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Secondary Pollutants
 Secondary pollutants- pollutants that have undergone ______________________________- in
the presence of sunlight, water, oxygen, or other compounds.
 Examples: ozone, sulfate and nitrate
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_________________ Sources of Air Pollution
 Volcanoes
 Lightning
 Forest fires
 Plants
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____________________________ Sources of Air Pollution
 On-road vehicles
 Power plants
 Industrial processes
 Waste disposal
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Photochemical Smog
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Temperature
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Atmospheric __________________________ affects the formation of smog.
1. Evaporation of VOC’s increase as the temperature ______________________.
2. NOx emissions from electric utilities also increase as air-conditioning demands increase.
3. Chemical reactions that form __________ proceed more rapidly at higher temperatures
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These factors combine to form even higher smog concentrations…___________________
feedback loop.
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Thermal Inversions
 Thermal Inversion- when a relatively ______________- layer of air at mid-altitude covers a layer
of cold, dense air below.
 The warm inversion layer traps ______________________- that then accumulate beneath it.
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Acid Deposition
 Acid deposition- occurs when nitrogen oxides and sulfur oxides are released into the
atmosphere and combine with atmospheric ___________________ and water. These form the
secondary pollutants nitric acid and sulfuric acid.
 Acid deposition increased substantially in the US from the 1940’s-1990’s due to human
activity.
 These secondary pollutants further break down into nitrate and sulfate which cause the acid in
acid deposition.
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Effects of Acid Deposition
 Direct effects
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Lowering the ____ of lake water
 Indirect effects
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_______________________ statues, monuments, and buildings
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Mobilizing metals that are found in soils and releasing these into surface waters
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Decreasing species diversity of aquatic organisms
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Ways to Prevent Air Pollution
 Removing sulfur dioxide from coal by fluidized bed combustion. (using less fuel: Better)
 ________________ converters on cars
 ___________________ on smoke stacks
 Baghouse filters
 Electrostatic precipitators
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Stratospheric Ozone
 The stratospheric ozone layer exists roughly ______________________ kilometers above the
Earth. ___________________________ layer
 Ozone has the ability to absorb _________________ radiation and protect life on Earth.
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Formation and Breakdown of Ozone
 First, UV-C radiation breaks the bonds holding together the oxygen molecule )2, leaving two free
oxygen atoms:
O2 + UV-C -> 2O
 Sometimes the free oxygen atoms result in ozone:
O2 + O -> O3
 Ozone is broken down into O2 and free oxygen atoms when it absorbs both UV-C and UV-B
ultraviolet light:
O3 + UV-B or UV-C -> O2 + O
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Anthropogenic Contributions to Ozone Destruction
 Certain chemicals can break down ozone, particularly ____________________.
 The major source of chlorine in the stratosphere is a compound known as
_____________________________ (CFCs)
 CFCs are used in refrigeration and air conditioning, as propellants in aerosol cans and as
“blowing agents” to inject air into foam products like Styrofoam.
 When CFCs are released into the _________________ they make their way to the stratosphere.
 The ultraviolet radiation present has enough energy to break the bond connecting chlorine to
the CFC molecule.
 which can then break apart the ozone molecules.
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Anthropogenic Contributions to Ozone Destruction
 First, chlorine breaks ozone’s bonds and pulls off one atom of oxygen, forming a chlorine
monoxide molecule and O2: O3 + Cl -> ClO + O2
 Next, a free oxygen atoms pulls the oxygen atom from ClO, liberating the chlorine and creating
one oxygen molecule: ClO + O -> Cl + O2
 One chlorine atom can catalyze the breakdown of as many as ____________ ozone molecules
before it leaves the stratosphere.
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Depletion of the Ozone Layer
 Global Ozone concentrations had decreased by more than ____%.
 Depletion was greatest at the ___________
 Decreased stratospheric ozone has increased the amount of __________ radiation that reaches
the surface of Earth.
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Indoor Air Pollutants
 Developing countries
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Wood, animal manure or coal used for __________________________ in developing countries.
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CO and PM’s
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Acute respiratory infections, pneumonia, bronchitis, cancer.
Developed countries
 More time _________________, better insulation, building materials made from petroleum and
plastics that give off vapors.
 Asbestos
 Carbon Monoxide
 Radon
 VOCs in home products
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Improve indoor air quality
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Keep __________ fresh- vacuum and clean up floors. Chemicals and allergens can accumulate
in dust on floors for decades.
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Keep your humidity at _________% to reduce mold and dust mites under control.
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No smoking in or around the home.- cigarettes contain more than _________ chemicals in them
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Test for ____________-colorless, odorless, tasteless radioactive gas that is the second leading
cause of lung cancer. Occurs naturally from the decay of the earth.
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Fragrance free- some plug in fresheners contain more than _______ VOCs, even several that are
deemed toxic by federal laws.