Chapter 22
Air and Noise Pollution
22.1 The Air Pollution Problem
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Harmful materials to the environment are called
pollutants.
Harmful substances released into the
atmosphere are called air pollution.
Evolution of pollution
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Air pollution is not a new problem it was first
reported in ancient Rome.
Then it become a widespread problem during
the 1700's in the industrial revolution.
There have been numerous cases of deaths
from everyday industrial pollutants.
Outdoor Pollutants
• Tiny particles suspended
in the atmosphere are
called particles.
• This can include traces
of lead, iron, pesticides,
fertilizers, and plant
pollen.
• These can be dangerous
to people since it can be
easily inhaled.
Oxides
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These are the most common gaseous
pollutants. They are made up from oxygen ad
one other compound.
They are formed from the burning of fossil fuels.
Photochemical Smog
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This is a yellow-brown haze that is formed when
sunlight reacts with pollutants produced by cars.
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Hydrocarbons- made from hydrogen and
carbon most commonly a pollutant in the form
of methane.
A similar pollutant is called Chlorofluorocarbons
made from carbon, chlorine, and flourine, they
were used in refrigerators, air conditioners, and
aerosol cans. CFC's destroy ozone.
Ozone Depletion
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Ozone is a corrosive, poisonous gas. There is
a layer 20 to 50 km above the Earth's surface.
It blocks the sun's harmful UV radiation.
Causes
• CFC's do not break
down in the lower part
of the atmosphere.
When it rises to the
stratosphere it breaks
down and releases
chlorine and fluorine.
This breaks down the
ozone in these layers.
Indoor Pollutants
• Plastic, insulation, and
cleaners give off harmful
fumes.
• The most harmful indoor
pollutant is cigarette
smoke.
Radon Gas
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It is a colorless, odorless, radioactive gas that is
given of when radium in soil breaks down.
These particles can attach to air particles and
be inhaled.
Carbon Monoxide
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Carbon monoxide binds with hemoglobin (part
of red blood cells) better than oxygen. This
prevents any oxygen from attaching to the cells.
22.2 Air Pollution and Living Things
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Particles in the air have been linked to two very
fatal diseases.
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Emphysema – a disease in which tiny air sacs in
the lungs break down.
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Cancer-cells grow abnormally and without restraint.
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Cigarette smoke is the leading cause of both of these
diseases.
Plants and Air Pollution
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Chemicals such as ozone and sulfur oxides
damage plants directly.
The U.S. Loses 10 billion dollars worth of crops
each year.
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The accumulation of pollutants in plants can
disrupt the food chain and in extreme cases can
kill grazing animals.
Global Warming cont.
• Global warming is the increase in Earth's average
surface temperature caused by an increase in
greenhouse gases.
• The temperature may increase and cause sea levels to
rise. This would cause some land to be under water.
Sea water would invade groundwater systems.
Global Warming
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The trapping of radiated heat by gases in the
atmosphere is called the greenhouse effect.
Some gases trap infrared radiation and heat up
the Earth. These are known as green house
gases.
How Acid Rain is Formed
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Water in the atmosphere becomes acidic when
it reacts with carbon dioxide forming carbonic
acid which has a pH of about 5.6.
22.3 Global Effects of Air Pollution
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There are three major air pollution problems
threatening the global environment:
1.) Acid Precipitation – rain or snow that is more
acidic than normal precipitation
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This can damage trees and can cause lakes to
become inhabitable.
22.4 Controlling Air Pollution
• Natural processes can control air pollution:
– 1. Precipitation – the most effective natural
method of controlling air pollution. Pollutants are
carried out of the air. This means that is placed
somewhere else.
– 2. Biological activity – many plants and organisms
remove carbon dioxide from the environment.
–3. Burying – when carbon is trapped
under ground it eventually turns into
fossil fuels.
–4. Ocean – the ocean removes large
amounts of carbon dioxide from the
atmosphere. This is dependent on the
temperature.
Human Controls
• 1. Cleaner automobiles - There are strict
emission control standards for all
automobiles. The only way to cut down
on all the emissions is to quit using
gasoline for fuel.
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2. Power plant regulations – certain
devices are now required to reduce
the pollution in factories.
22.5 Noise Pollution
• The unit used to measure
sound intensity is a decibel.
• Physical pain and severe
hearing loss happens at
anything over 120dB.
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Stress caused from loud persistent
noise leads to severe health
problems.
• In 1972, Congress passed the Noise Control
Act. This set standards for maximum noise
levels.