Pollution
P.Lobosco
The Balance of the Environment

The balance of the environment can be
upset by the way in which humans obtain
and use natural resources. If humans use
renewable natural resources faster than
they can be replaced, the balance will be
upset. If we damage one resource in the
process of obtaining or using another
resource, the balance will be upset.
Pollution

Pollution is the release into the
environment of substances that change
the environment for the worse. Most
pollution is the result of human activities.
The Trail of Pollution

In order to make a can of soda, the aluminum
must be removed from the ground. Digging
scars the land. Chemicals used in the factory to
produce aluminum become waste that is
discarded and ends up in a river as pollutants.
The fuel burned to to make the aluminum into a
can produces smoke that pollutes the air. The
process used to make the soda to go into the
can also produces pollutants. The consumer
buying the can disposes of it as litter, another
form of pollution.
Sources and Solutions

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A great amount of pollution is tied directly to
energy use. The world’s heavy dependence on
fossil fuels has made pollution a major concern.
The activities involved in finding and using fossil
fuels have led to land, air and water pollution.
Solutions can involve new ways to regulate and
reuse materials. Solutions can also involve
alternative energy to replace fossil fuels.
Main Types of Pollution
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Land
Air
Water
Land Pollution
Land Pollution

Most of the energy (90%) used comes
form fossil fuels. Solar, wind, water and
other alternative energy resources
account for only 5%. Nuclear energy
accounts for the other 5%. Obtaining both
fossil fuels and nuclear energy can pollute
the Earth.
Coal

The use of coal was an important step in
the industrialization of the United States.
Coal near the surface is strip mined. This
process badly damages the land and
causes soil and land pollution. Fertile
topsoil is buried under tons of rock. When
the rock is exposed to precipitation, acids
and other harmful chemical seep into the
ground, polluting the soil and land.
Hazardous Wastes

Wastes from factories may pollute the land
with toxic chemicals, called hazardous
wastes. Hazardous wastes can cause
death or serious damage to human health.
Factories that produce fuels and
petrochemicals from petroleum are the
major sources of hazardous waste. When
improperly stored in barrels buried in
dumps, the wastes seep into the soil.
Management of Hazardous
Wastes
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The best solution is to produce less
hazardous wastes.
In some cases, industries can reuse the
wastes.
Other wastes might be chemically treated
to change the toxic substances they
contain into nontoxic substances.
Radioactive Wastes

Radioactive wastes are the wastes
produced as a result of the production of
energy in nuclear power plants.
Radioactive wastes are classified as either
high-level or low-level. High-level wastes
are primarily the used fuel rods from a
nuclear reactor. Low-level wastes may
include contaminated equipment used in
the power plant.
Disposing of Radioactive Wastes

Low-level wastes decay quickly. Highlevel wastes may of half-lives of 10,000
years or more. Isolating them from the
environment for that length of time is
almost impossible. In the past, high-level
wastes were sealed in concrete or glass
containers. The containers usually began
to corrode or leak.
New Method of Disposal

A new method of disposal has been
proposed. Wastes can be buried in rock
formations that are not subject to
movement of in salt mines. This is known
as Geologic disposal. Disposal in ocean
beds is another alternative. Some
scientists have suggested shooting
rockets carrying high-level wastes into the
sun.
Solid Wastes

Americans produce about 11 billion tons of
solid wastes every year. Solid wastes are
useless, unwanted or discarded materials.
They include agricultural wastes,
commercial and industrial wastes and
household wastes. Another word for solid
waste is garbage. Mountains of garbage
once surrounded cities.
Sanitary Landfills

One way to deal with solid waste dumps is
to cover them with thick layers of soil. In
1976 the United States Congress
prohibited open dumps. They ruled that all
existing open dumps were to be converted
to sanitary landfills. All garbage is
compacted and covered at least once a
day with a layer of soil. Once filled they
can be used as parks.
Problems with Landfills

A problem with sanitary landfills is that
when compacted garbage begins to
decompose and methane gas is produced.
It burns easily and is a fire hazard. Gas
wells need to be installed. Wastes can
ooze out of landfills and pollute the
surrounding soil. The biggest problem is
finding a place to put them.
Ocean Dumping

At one time, solid wastes were commonly
towed offshore and dumped into the
ocean. Much of the debris has washed up
on beaches. Today some debris is still
dumped.
Burning Garbage

Burning garbage in open dumps and in the
incinerators of apartment buildings and hospitals
was used at one time. Because burning
releases harmful gases, the practice is being
halted. Sometimes the old incinerators are
replaced with highly efficient incinerators. Some
buildings use waste to energy incinerators. The
heat produced is used to convert water into
steam which is then used to generate electricity
or heat the building.
Recycling Solid Waste

Most environmentalists prefer recycling.
Recycling not only gets rid of solid waste
but also creates useful materials.
Air Pollution
Air Pollution

The most significant source of air pollution is
motor vehicles. The air is made up of oxygen,
nitrogen, carbon dioxide, and water vapor.
When fossil fuels are burned, pollutants enter
the air. The gasoline burned in the engines of
automobiles contains hydrocarbons. Pollution
occurs when the gasoline is not completely
burned in the engine. Some hydrocarbons as
well as carbon monoxide enter the air.
Smog

Hydrocarbons, carbon monoxide and
several other gases often react in sunlight
to form a thick brownish haze called smog.
Smog contains chemicals that irritate the
eyes and make breathing difficult. Smog is
very dangerous for people with asthma.
Smog can also damage or kill plants.
Smog can build up in a temperature
inversion. This happens in Los Angeles.
Temperature Inversion

A temperature inversion occurs when cool air
near the Earth’s surface becomes trapped under
a layer of warm air. Normally, cool air is heated
by the Earth’s surface and rises, taking
pollutants with it. But during a temperature
inversion, the layer of warmer air acts as a lid
and the pollutants are trapped in the cooler air
near the surface. In the 1940’s some died and
others were hospitalized in Donora, PA during a
temperature inversion.
Acid Rain

Factories and cars release many
pollutants into the air. Some of these
pollutants include sulfur and nitrogen
compounds called oxides. In the
atmosphere, sulfur oxides and nitrogen
oxides combine with water vapor and form
acids: sulfuric and nitric. These acids fall
to Earth as precipitation known as acid
rain.
Problems with Acid Rain

Very often acid rain falls many kilometers
away from the original source of the
pollution. Acid rain from factories in
Germany, France and Great Britain killed
fish and trees in Sweden. The best way to
control acid rain is to burn low-sulfur coal
but it is expensive.
Indoor Air Pollution

Indoor pollution is a serious problem.
Some appliances used in homes and
offices give off potentially dangerous
gases. In addition, often the houses are
insulated in order to be energy efficient.
Pollutants that might otherwise escape
through cracks are trapped inside. One of
the leading causes of indoor pollution is
smoking.
Water Pollution
Water Pollution

More and more of the water on Earth is
becoming unusable. One reason for a
shortage of water is water pollution.
Obtaining and using energy resources are
the major causes of water pollution.
Sources of Water Pollution
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Acid Rain
Strip Mining
Oil Spills
Nuclear power
Hazardous Wastes
Sewage and Agricultural Runoff
Acid Rain

When acid rain falls into lakes, rivers and
streams, they increase the acidity level of
the water. Most fishes and other
organisms that live in water can survive in
only a narrow range of acidity. Acid rain
kills many of the organisms living in the
water.
Strip Mining

Strip mining for coal releases pollutants
that may run off into lakes and streams or
may seep in to the soil to contaminate
groundwater.
Oil Spills

Petroleum is often found under the ocean
floor. To obtain this petroleum, offshore oil
wells are constructed. Drilling accidents
occurs and large amounts of oil spill into
the oceans. Oil spills also occur when
tanker carrying oil are damaged. Tankers
also deliberately flush waste oil into the
ocean. Plants and animals are killed.
Nuclear Power

Water is needed to cool the reactors in
nuclear power plants. Cold water from
lakes and rivers is used for this process.
As a result of this a lot of hot water is
generated. This heated water is then
discharged in to lakes. This causes the
temperature to rise. This temperature
increase is called thermal pollution since
organisms die when temperatures rise.
Radioactive Wastes

Radioactive wastes can also be a sources
of ling-term water pollution. Radioactive
wastes stored in underground containers
may leak and pollute groundwater.
Pollution of the oceans occurs if these
wastes are dumped in the ocean.
Hazardous Wastes

Prior to the 1970’s many industries
dumped chemicals and other hazardous
wastes directly into streams and other
nearby bodies of water. Today they are not
deposited directly into water, instead they
are buried. Often leaks occur and the
groundwater is polluted. Illegal dumping,
called midnight dumping, also occurs.
Sewage

The greatest threat to human health
comes form sewage. Sewage is the
waste material that is carried away by
sewers and drains. Sometimes it is
dumped directly into streams. This
sewage often contains disease-causing
bacteria and viruses. Drinking water may
become contaminated.
Danger to Fish

Fish living in polluted water are also unfit
for human consumption. Untreated
sewage is also harmful to the fish and
other organisms that live in the water.
Bacteria in the water break down the
sewage. In the process, the bacteria use
oxygen. If too much oxygen is used, fish
and other organism may die from lack of
oxygen.
Agricultural Runoff

The runoff of agricultural wastes and
chemicals from farmlands also contributes
to water pollution. Chemicals such as
Phosphates and nitrates are used in
fertilizers to improve the growth of crops.
When fertilizers run off the land in to a
lake, they stimulate the growth of algae.
The algae then use up the oxygen in the
lake. Pesticides also enter the water.
What Can Be Done About
Pollution?

Pollution can be reduced by conserving
energy, by finding cleaner ways to use
energy, and by making sure that wastes
are disposed of in the safest possible
ways.
Conservation

Conservation is the wise use of natural
resources so that they will not used up too
quickly or used in a way that will damage
the environment. The environment
benefits two ways. First, nonrenewable
resources last longer. Second, pollution is
reduced.
Examples of Conservation
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Recycling
Carpooling
Public Transportation
Turning down the thermostat in the winter
and turning up in the summer
Insulate homes
Use less water
New Technologies

New technologies can reduce pollution by
creating cleaner and more efficient ways
of obtaining and using energy resources.
Technology can also help develop
alternatives to fossil fuels.
Scrubber Systems

The burning of coal has been made less
damaging to the environment by the use
of scrubber systems. A scrubber system
works like a shower. As sulfur oxides are
released from burning coal, a highpressure spray of water dissolves the
oxides before they can react with the
water vapor. They can be used on
smokestacks.
Oil Drilling and Spills

New methods have been used to drill for
oil under the ocean floor in order to reduce
underwater leaks. Several new methods
have been developed for cleaning up oil
spills with vacuum systems. Oil-eating
bacteria have also been developed.
Waste Disposal
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Hazardous waste should be separated
from industrial waste.
Hazardous waste should be reused or
recycled when possible.
The waste should be treated chemically to
destroy the toxic materials they contain.
The wastes should be buried in landfills
with many safeguards to prevent leaks.
Everyone’s Responsibility

Pollution is mainly caused by the activities
of people. It is important to realize that the
activities of people can also reduce
pollution. Everyone can help!