Air Quality
Obj-Discuss the sources of air pollution and the importance of
air quality relative to plant and animal life.
What is Air?
 Air: the invisible, tasteless and odorless mixture of
gases that surrounds us
 Gases in the air:
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Nitrogen
Oxygen
Carbon Dioxide
Hydrogen & more
 Atmosphere: the mass of air that surrounds the earth
Air Quality
 The suitability of the air for use by living organisms
 High quality=free of pollution
 Low quality=contains hazardous materials
Types of Air
Ambient Air
 Air/atmosphere outside
 Most important air in air
quality
 Affected by materials
released into it i.e. factory
smoke, exhaust from car
 EPA has standards for
maximum amount of
pollution that can be in
ambient air
Inside Air
 Quality of inside air is related
to what is released into it
 Indoor air should have some
exchange with ambient air to
be healthy for human use
 Radon: invisible, tasteless,
and odorless radioactive gas
that comes from the natural
decay of uranium in the soil
 Enters a building through
cracks in floor & walls
Air Pollution
 The presence of materials in the air that damage air
quality
 Greatest problems due to pollution created by humans
in factories, automobiles, etc.
 Air pollutant: any material that causes air pollution
 Ex) gas, dust, smoke, pollen
 Air quality standard: the maximum level of atmospheric
pollution allowed at one time in a geographical area
 Set by EPA
 Designed to limit the amount of pollution forcing those
who pollute the air to stop
Air Pollution
 The nature of air allows widespread pollution
 Wind currents can move polluted air across continents
and over oceans
 Air will carry pollutants greater distances than water
 Weather fronts move air pollution across large areas
 Airshed: geographical area that may release materials
into the air
 Pollution from U.S. power plants may result in acid rain in
Canada
 Since air moves, pollution created in one place can result
in pollution problems elsewhere
Air Pollution
 2 major types of air pollutants are gases and
suspended solid particles
Gas Pollutants
1. Carbon forms-hydrocarbons, carbon monoxide, and
carbon dioxide
 Primarily released by the petroleum industries and
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combustion (burning) of materials containing carbon
Industrial processes from oil refining, steel mills, and
chemical manufacturing plants are a major source of air
pollution
2. Sulfur oxides
 Sulfur is usually found as an oxide in the air
 Sulfur oxides are sulfur dioxide and sulfur trioxide
 When sulfur compounds mix with water vapor, the end
result is acid rain. This the best example of air pollution
that affects wildlife, especially fish.
Gas Pollutants
3. Nitrogen Oxides
 During combustion, nitrogen in fuel forms nitrogen
oxides
The oxides formed are nitrogen monoxide and nitrogen
dioxide
Nitrogen oxides pose health problems similar to sulfur
oxides
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4. Photochemical Oxides
 Primary ingredient=smog
 The ozone layer of the earth is being damaged by
pollutants, namely chlorofluorocarbons (CFC’s)
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Freon in refrigerators and air conditioners
Spray cans
Suspended Solid Particles
 Particulate includes small particles similar to dust and
droplets of water
 Includes acid droplets, salts of metals, pollen, and other
substances
 Smoke from factories, burning trash, forest fires, and
dusts from roads are sources of solid particles
 Scrubbing: use of procedures to remove particulate
from industrial exhaust
 Use of a fine spray mist of water through smoke
 Use of electrostatic precipitators
Suspended Solid Particles
 Two metals are major causes of air pollution:
 Lead- a heavy metal used in manufacturing paint and
dinnerware
 Paint containing lead was once widely used
 Tiny particles of paint could get into food or on toys that small
children put into their mouths
 Most uses of lead have been stopped
 Mercury- a heavy metal used widely in thermometers
 Is being eliminated because of mercury poisoning
 Can cause death of fish
 Human symptoms=loss of memory, birth defects, involuntary
shaking of the body
Effects of Air Pollution
 Human Health Problems
 Respiratory diseases i.e. lung cancer, emphysema,
bronchitis, black lung disease
 Asphyxiation- a condition that occurs when the body is
not getting adequate oxygen due to carbon monoxide
accumulating in the blood
 Pollution can injure farm animals, pets, and wildlife
 Feed produced in high pollution areas may be poisoned
 Fluorides are particularly damaging to animals
 Acid rain has destroyed fish populations
Effects of Air Pollution
 Pollution may damage fruits, vegetables, flowers, trees, and lawns
 Pollution may cause chlorosis (plant leaves turn yellow & fall off)
 The major effect of air pollution on the climate has been the
greenhouse effect
 Pollutants cause the atmosphere to hold in heat and increase the
earth’s temperature
 Air contents influence climate
 Contents absorb radiation to protect the earth
 The contents hold heat against the earth’s surface
 Visibility is impaired
 Property damage
 Acid rain- rust & corrosion on equipment and fish crops lost
 Damage to buildings
 Changes the ecosystem by affecting the entire food chain
Determine Air Quality
Obj- Summarize how air pollution is detected and controlled
How Air Pollution is Tested &
Measured
 Air quality is difficult to test because of the nature of the air
 Invisible & moves about
 Ambient Air Monitoring
 Samples collected with an air pollution sampling pump: Collects
& measures the quantity of air being sampled; then the sample
is passed into an absorbing solution. Solution is chemically
analyzed. Specially designed kits are used to test for
hazardous materials.
 Point Source Emissions Monitoring
 Emission: a gas born pollutant that is released into the air
(smoke & fumes)
 Point Source Air Pollution: a specific place where air pollution
originates; Examples) factories with tall smoke stacks
Measuring Pollutants
 Volume per Volume- the number of parts of a pollutant
in the air
 Expressed as “parts per volume”
 May also be expressed in parts per million (ppm)
 Weight per Volume- the weight in parts per million
(ppm)
 Used to measure the concentration of a pollutant in the
air
 Stated as micrograms per cubic meter
 Dimension measurement- used to measure solid
particles, called particulate, in the air
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Protecting
the
Air
Controlling emissions
 Scrubbers can be used on smoke stacks to remove gases and particulate
 Fuels that produce less sulfur and other wastes can be used
 Emission control devices i.e. catalytic converter
 Reusing and Recycling
 Save the release of pollutants that manufacturing a product would generate
 Conserve limited natural resources
 Using Alternative Methods
 New refrigerants have replaced freon in refrigerators and air conditioners
 No till farming has reduced the need to plow and reduces dust
 IPM reduces the use of hazardous pesticides
 Practicing Safety
 Close windows and stay inside when outside pollution level is high
 Wear protective masks around hazardous chemicals
 Find a current event that
So what is going
on in our world
today?
Several strides have been made
toward cleaner air beginning with
the Clean Air Act that was last
revised in 1990.
highlights what places or
businesses are doing to
reduce the pollution they
put into the atmosphere
 Write a ONE PAGE
summary of the article.
Be sure to include the title
of the article, author, and
the date published.