Pollution

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Pollution

• P.Lobosco

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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.

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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.

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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.

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Sources and Solutions

• A great amount of pollution is tied directly to
  energy use. The worlds 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.

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Main Types of Pollution

• Land
• Air
• Water

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Land Pollution
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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.

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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.

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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.

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Management of Hazardous Wastes

• 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.

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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.

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Disposing of Radioactive Wastes

• Low-level wastes decay quickly. High-level
  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.

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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.

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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.

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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.

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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.

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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.

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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.

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Recycling Solid Waste

• Most environmentalists prefer recycling.
  Recycling not only gets rid of solid waste but
  also creates useful materials.

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Air Pollution
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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.

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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.

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Temperature Inversion

• A temperature inversion occurs when cool air near
  the Earths surface becomes trapped under a layer
  of warm air. Normally, cool air is heated by the
  Earths 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 1940s some died and others were
  hospitalized in Donora, PA during a temperature
  inversion.

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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.

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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.

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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.

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Water Pollution
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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.

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Sources of Water Pollution

• Acid Rain
• Strip Mining
• Oil Spills
• Nuclear power
• Hazardous Wastes
• Sewage and Agricultural Runoff

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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.

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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.

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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.

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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.

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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.

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Hazardous Wastes

• Prior to the 1970s 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.

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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.

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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.

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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.

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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.

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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.

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Examples of Conservation

• Recycling
• Carpooling
• Public Transportation
• Turning down the thermostat in the winter and
  turning up in the summer
• Insulate homes
• Use less water

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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.

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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 high-pressure spray of water dissolves the
  oxides before they can react with the water
  vapor. They can be used on smokestacks.

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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.

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Waste Disposal

• 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.

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Everyones 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!