Air
Chapter 2
• Name five primary air
pollutants, and give
sources for each.
• Name the two major
sources of air pollution in
urban areas.
• Describe the way in
which smog forms.
• Explain the way in which
a thermal inversion traps
air pollution.
The Air Pollution Problem
• Air is a mixture of gases.
– Nitrogen ___% and Oxygen ___% followed by
_______________ of Argon, CO2, and WV.
• Air pollution is the contamination of the
atmosphere by wastes from sources such as
industrial burning and automobile exhausts.
• Earliest reference to air pollution dates back
to ancient Rome.
• All major air pollution disasters have
occurred in industrialized areas.
• Substances that pollute
the air can be in the
form of solids, liquids,
or gases.
• Most air pollution is the
result of human
activities, but some
pollutants are natural,
including dust, pollen,
spores, and sulfur
dioxide from volcanic
eruptions.
Primary and Secondary
Pollutants
• A ______________ is a pollutant that is put
______________________________or natural
activity. An example would be soot from smoke.
• .
• A _________________ is a pollutant that
_______________________________,
natural components in the air, or both. An
example would be ground-level ozone.
• Ground level ozone forms when the emission
from cars react with the UV rays of the sun
and then mix with the oxygen in the
atmosphere
Outdoor Pollutants
• Particulates __________________________
• ____________________________.
– Ex. Ash, dust, and traces of metals.
• ____________ – compounds of oxygen and
another element.
– Forms acid when it chemically reacts with water.
– Most of the gaseous pollutants come from these
chemicals.
• ____________________________– yellow-brown
haze formed when sunlight reacts with pollutants
produced by cars.
• _____________________ (CFCs) – compounds
of C, Cl, and F once used in refrigerators, air
conditioners, aerosol cans, and in the production
of polystyrene.
Smog
Smog _______________________________
____________________________________
____________________________________.
Smog results from chemical reactions that
involve sunlight, air, automobile exhaust, and
ozone.
Pollutants released by vehicles and industries
are the main causes of smog.
Particulates
Indoor Pollutants
• Improving air circulation can reduce the
amount of pollutants in your home.
• The combination of particulates, gases, and
other chemicals contained in cigarette
smoke makes it the deadliest of all indoor
pollutants.
Radon – ________________________________.
Radon System
Short-Term Effects of Air
Pollution on Health
• Many of the effects of air pollution are short-term and
reversible if their exposure to air pollution decreases.
• For example: headache; nausea; irritation to the eyes,
nose and throat; coughing; tightness in the chest; and
upper respiratory infections, such as bronchitis and
pneumonia.
• Pollution can also make the conditions of asthma and
emphysema worse for certain individuals.
Long-Term Health Effects of Air
Pollution
• Long-term effects on health that have been
linked to air pollution include emphysema,
lung cancer, and heart disease.
• Long-term exposure to air pollution may
worsen medical conditions suffered by older
people and may damage the lungs of children.
Air Pollution and Living Things
• Air pollution has been linked to many health
problems.
• Carbon Monoxide (CO) – ___________________
__________________________reducing it from
reaching cells and resulting in stress and death at
high levels.
• Cigarette smoking is a factor in causing lung
cancer, emphysema, and heart disease.
Asbestos
• _____________ is any of six silicate minerals
that form bundles of minute fibers that are heat
resistant, flexible, and durable.
• Asbestos is primarily uses as an insulator and as a
fire retardant, and it was used extensively in
building materials.
• However, for all of its uses, the government
banned the use of most ________________
_______________________.
• Asbestos fibers can cut and scar the lungs,
causing the disease asbestosis.
• Victims of the disease have more and more
difficulty breathing and may eventually die
of heart failure.
Other Health Issues
• Emphysema – a disease in which tiny air
sacs in the lungs break down.
• Cancer – a disease in which cells grow
abnormally and without restraint.
The US loses up to $10
Billion worth of crops each
year because of air pollution.
Industrial air pollutants can
contaminate farmland and
grazing areas leading to high
levels of lead and zinc.
Global Effects of Air Pollution
• Three major air pollution problems
threatening the global environment:
– Acid Precipitation
– Ozone Depletion
– Global Warming
A ___________________________is the atmospheric
condition in which warm air traps cooler air near Earth’s
surface.
The warmer air above keeps the cooler air at the surface from
moving upward. So, pollutants are trapped below with the
cooler air.
If a city is located in a valley, it has a greater chance of
experiencing temperature inversions (as seen in LA).
What Causes Acid Precipitation?
• Acid precipitation _____________________
_____________________________________
_______________________________When
fossil fuels are burned, they release oxides of
sulfur and nitrogen.
• When these oxides combine with water in the
atmosphere they form sulfuric acid and nitric
acid, which falls as acid precipitation.
Acid Precipitation
• Acid precipitation has become more
common in the last 200 years due to
increased fossil fuel use.
What Causes Acid Precipitation?
What Causes Acid Precipitation?
• This acidic water flows over and through the
ground, and into lakes, rivers, and streams.
• Acid precipitation can kill living things, and
can result in the decline or loss of some local
animal and plant populations.
What Causes Acid Precipitation?
• A pH number _________________________
_____________________________________
___________________________________.
• Each whole number on the scale indicates a
tenfold change in acidity.
• A pH of 7 is neutral, a pH of less than 7 is
acidic, and a pH of greater than 7 is basic.
• Pure water has a pH of 7.0, while normal
precipitation has a pH of about 5.6.
What Causes Acid Precipitation?
• Normal precipitation is slightly acidic because
atmospheric carbon dioxide dissolves into the
precipitation and forms carbonic acid.
• Precipitation is considered acid precipitation if it has
a pH of less than 5.0
• The pH of precipitation in the eastern U.S. and
Canada ranges from 4.2 to 4.8, with the most acidic
precipitation occurring around Lake Erie and Lake
Ontario.
Acid Rain
• _______________is the sudden runoff of large
amounts of highly acidic water into lakes and
streams when snow melts in the spring or
when heavy rains follow a drought.
• This phenomenon causes large numbers of fish
to die, and affects the reproduction of fish and
amphibians that remain. They produce fewer
eggs, and those eggs often do not hatch. The
offspring that do survive often have birth
defects and cannot reproduce.
International Conflict
• One problem in controlling acid precipitation
is that pollutants may be released in one
geographical area and fall to the ground
hundreds of kilometers away.
• For example, much of the acid precipitation
that falls in southeastern Canada results from
pollution produced in the northeastern United
States.
Ozone Depletion
• O3 – Ozone Gas
• Atmospheric ozone helps life on Earth by
blocking out UV rays.
• Found in the Stratosphere.
• Corrosive and poisonous gas on Earth’s
surface.
Hole in the Sky
• Early 1980’s, scientists discovered a thin
area, or hole, in the ozone layer over the
South Pole.
• UV radiation can cause sunburn, blindness,
and skin cancer as well as severe crop
damage.
Causes of Ozone Depletion
• Ozone depletion will continue because
CFCs last up to 50,000 years.
• Chlorine and fluorine are the atoms
responsible for destroying ozone molecules.
Global Warming
• Light energy enters the atmosphere and is
absorbed at the surface. Light energy is
changed to heat. Heat energy is radiated
back to space in the form of infrared
radiation.
The Greenhouse Effect
• CO2 is the most significant greenhouse gas emitted in
large quantities by humans.
• Greenhouse effect got its name because heat is
trapped.
• Ice cores – long cylinders of ice that are drilled and
removed from deep within a sheet of polar ice.
• Ways to reduce Greenhouse Gases in the atmosphere:
– Electric Cars
– Solar Power
– Increasing Fuel Efficiency Standards
Effects of Greenhouse Gas Pollution
• During the past 150 years, levels of atmospheric CO2
has increased due to increased fossil fuel use.
• Global Warming – _________________________
__________________________________________
_______________________________
• Some computer models project that Earth’s
temperatures will rise by 2 – 4 degrees C.
• Ice Caps will melt, coastal areas will flood, weather
patterns will change, salt water will enter freshwater
aquifers.
Controlling Air Pollution
• _____________________, passed in 1970 and
strengthened in 1990, gives the Environmental
Protection Agency (EPA) the authority to regulate
vehicle emissions in the United States.
• The EPA required the gradual elimination of lead in
gasoline, decreasing lead pollution by more than 90
percent in the United States.
• In addition, ___________________, required in all
automobiles, clean exhaust gases of pollutants
before pollutants are able to exit the tail pipe.
• The Clean Air Act requires many
industries to use __________ or
other pollution-control devices.
• Scrubbers remove some of the more
harmful substances that would
otherwise pollute the air.
• A scrubber is a machine that moves
gases through a spray of water that
dissolves many pollutants.
Ammonia is an example of a
pollutant gas that can be removed
from the air by a scrubber.
• _____________________
are machines used in
cement factories and
coal-burning power plants
to remove dust particles
from smokestacks.
• In an electrostatic
precipitator, gas
containing dust particles is
blown through a chamber
containing an electrical
current.
•An electric charge is
transferred to the dust
particles, causing them
to stick together and to
the sides of the
chamber.
Natural Air Pollution Controls
• Precipitation is the most effective natural
method of removing particulates and
aerosols from the air.
• Two ways to remove CO2:
– Biological Activity (Photosynthesis and Shell
Formation)
– Oceans (Cold temperatures hold more CO2)