AIR POLLUTION

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AIR POLLUTION

• Composition of Air
• Mixture composed of 78 Nitrogen (N2), 21 Oxygen
  (O2), 0.06 Carbon Dioxide (CO2)
• Also contains water vapor, gaseous pollutants,
  and solid particles (particulates)
• Air Pollution a change to the atmosphere that
  has harmful effects
• Types of Air Pollution
• Smog
• Acid Rain
• Global Warming
• Destruction of the Ozone Layer
• Indoor Air Pollution

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AIR POLLUTION

• Smog combination of smoke and fog
• Photochemical Smog thick, brownish haze when
  certain gases in the air react with sunlight
• Gases mainly come from cars and trucks
• Gases form ozone a toxic gas
• Temperature Inversion a layer of warm air
  prevents the pollution (smog) from rising above
  the city
• Problems include
• Itchy, watery eyes
• Scratchy throat
• Lung problems
• Harms the bodys defense against illness

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AIR POLLUTION

• Acid Rain - a condition that arises when certain
  gases in the atmosphere react with rain water,
  turning it acidic
• Nitrous and Sulfer Oxides water ? nitric acid
  and sulfuric acid
• Gas pollutants come from car engines (nitrous
  oxide) and coal burning plants (sulfer oxides)
• Lowers pH of rain water below its normal value
• pH a scale that measures the acidity of
  solutions
• Acid below 7 Neutral 7 Base above 7 (14
  is highest)
• Unpolluted rain water is 5.2 (slightly acidic) ?
  acid rain is when the pH falls well below that
  level
• Damages environment
• Can kill large areas of forests
• Releases heavy metals out of the soil
• Makes waterways unsuitable for aquatic life
• Can destroy certain materials in buildings and
  statues

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AIR POLLUTION

• Ozone Depletion harmful pollutants reacting
  with a layer of our atmosphere known as the ozone
  layer, causing it to decrease
• Ozone Layer a layer of the atmosphere that
  contains a small amount of ozone (O3) gas
• About 30 km above surface
• Helps protect against ultraviolet radiation from
  sun ? UV rays cause sunburn and skin cancer
• Ozone absorbs UV energy keeps it from getting
  to surface
• Ozone is recycled (see Figure 6, P. 145)
• Chlorofluorocarbons (CFCs) molecules that
  react with ozone, stopping it from being recycled
• Come from air conditioners, refrigerators, fire
  extinguishers, aerosol cans
• Now CFCs are banned in most countries
• Large hole over Antarctica and Australia

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AIR POLLUTION

• Global Warming the idea that certain pollutants
  in the atmosphere are causing the temperature of
  the Earth to rise too quickly
• Greenhouse effect certain compounds trap the
  heat entering the Earths atmosphere prevents
  it from reflecting back into space
• Greenhouse gas gases that cause the greenhouse
  effect
• Carbon dioxide is most common greenhouse gas
• Works like a car window on a hot summer day ?
  heat can get in, just cant get back out
• Natural and needed ? the Earths temperature
  would be way too cold without this effect
• Some scientist worry that too many greenhouse
  gases are accumulating in our atmosphere
• Carbon dioxide is on the increase
• Burning of fossil fuels
• Deforestation
• Other greenhouse gases include water vapor,
  methane, and certain nitrogen and sulfur
  compounds
• Potential Consequences
• Dramatic changes in climate
• Coastal flooding melting of polar ice caps
• Mass extinction weather changing faster than
  organisms can adapt
• NOT ALL SCIENTISTS AGREE THAT GLOBAL WARMING IS
  HAPPENING!

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AIR POLLUTION

• Indoor Air Pollution
• Allergens such as pollen, dander, dust
• Cigarette smoke
• Asbestos used to be used as an insulator
• Associated with lung disease
• Carcinogenic linked to causing cancer
• Has to be removed now in public buildings
• Carbon Monoxide CO
• Description Colorless odorless gas
• Problem Binds with blood cells that carry
  oxygen keeps oxygen from getting to body cells
• Source when wood, coal, oil or gas are not
  burned completely
• Can by detectors to warn if levels get too high
• Radon
• Description colorless, odorless gas that is
  radioactive
• Problem can cause lung problems and cancers
• Source formed naturally by rocks underground
  leaks in through cracks in basements
• Can install ventilation units to keep Radon from
  building up

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AIR POLLUTION

• Solutions
• Emissions control
• Emissions solid particles and gas that are
  released into the air
• Laws set up to limit what factories can put into
  the air
• Scrubber using water to clean emissions before
  releasing into atmosphere
• Catalytic converter a device in cars and trucks
  that reduces emissions of carbon monoxide,
  hydrocarbons, nitrogen oxides
• Forms less harmful carbon dioxide and water
• CFC substitutes
• General Conservation Practices
• Reduse, reuse, recycle
• Carpool, find alternative ways for transportation
• Use less energy
• Support agencies and organizations that are for
  protecting the environment