AIR POLLUTION Chapter 22

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AIR POLLUTIONChapter 22
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INTRODUCTION

• Pure air does NOT exist! Air impure to the degree
  we call polluted is an increasingly serious
  problem.
• Air pollution has many different manifestations,
  depending on who offends and who is offended.
• To the average home owner it means eye
  irritation, added costs due to excess laundry and
  cleaning bills, excessive house painting , and
  car-finish deterioration.

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Cont.

• To the farmer it means damaged crops and
  live-stock. To the airline pilot it means
  increased hazards in taking off and landing due
  to poor visibility.
• To industry it means rejects of precision
  materials, process control problems, and poor
  public relations.
• To everyone it means serious health problems from
  ingesting pollutants such as sulfur dioxide,
  carbon monoxide, oxides of nitrogen, dust, soot,
  pollen and other contaminants.

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Pollutants

• Pollutants are harmful substances that enter the
  environment.
• Air pollution may be made up of particulates or
  gases, usually OXIDES.
• Pollutants can be present outdoors or indoors

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Outdoor Pollutants

• Particulates-tiny solids suspended in the
  atmosphere
• -ash, dust, soot from burning organic matter
  metals like lead, iron, copper
• these are dangerous because they easily can
  become trapped in lungs
• Gaseous- oxides are cmpds of 02 another
  element-burning of fossil fuels releases these
  gases

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Photochemical Smog

• Photochemical Smog- yellow-brown haze formed when
  sunlight reacts with pollutants produced by car
  emissions
• - Ozone is one of the chemicals highly
  corrosive in large amounts can also be poisonous
  to living things. NO2 gives PS its distinct brown
  color.

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Hydrocarbons

• Hydrocarbons- Methane most common pollutants-
  decaying organic matter or as a by product or
  burning organic matter.

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CFSs

• CFCs- cmpds of chlorine, carbon, and fluorine
  once used in refrigerators, air conditioners, and
  aerosol cans.

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Indoor Pollutants

• Home products- such as plastic, insulation, and
  cleaners give off harmful fumes.
• Cigarette smoke- extremely harmful to both
  smokers and nonsmokers
• Microorganisms- ventilation ducts contain
  bacteria and fungi
• Radon- a colorless odorless radioactive gas.
  Radon forms when radium, a radioactive element in
  soil breaks down. Radon from soil is drawn into a
  home through the basement.

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Air pollution and its effects on living things

• Air pollution can affect human health and the
  health of plants and animals.
• Humans health problems can range from eye and
  respiratory tract irritation to emphysema and
  lung cancer.
• Air pollution can also damage crops and be passed
  from contaminated food and water to grazing
  animals

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Human diseases
Lung cancer
emphysema
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Crop damage by air pollution
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Global effects of air pollution

• Air pollution can have global as well as local
  effects.
• Acid precipitations is rain or snow with a very
  low pH, resulting from oxides combining with
  water in the air.

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Cont.

• Sulfuric and nitric acid falls on the earth in
  the form of acidic precipitation destroying
  entire ecosystems
• Sweden- 20,000 lakes are too acidic to allow fish
  to survive
• Thousands of other lakes in Norway, Canada and
  the Northeastern US are so acidic that they
  contain no fish or plant life.

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Ozone depletion

• At the surface of Earth, Ozone is a corrosive,
  poisonous gas.
• 20-50 Km above the earths surface it is vital
  for life as we know it! Ozone absorbs most of the
  UV radiations given off by the sun, before they
  reach the earths surface. UV radiations are
  damaging to living things

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Ozone holes over North and South Poles
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Continue

• Ozone depletion results from the breakdown of O3
  molecules in the stratosphere by CFSs. (Cl and
  Fl)
• Experiments have proven that natural sources
  contribute very little chlorine to the
  stratosphere we are the major producers of
  fluorine and chlorine in the stratosphere.

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Global Warming

• The greenhouse effect-caused by gases such as CO2
  in the atmosphere, could lead to global warming.

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Global Warming cont.

• Deforestation at an increase speed also causes
  this warming trend.
• Every second, a rainforest the size of
• a football field disappears.

Amazon rain forest
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Controlling Air Pollution

• Some air pollutants are removed by natural
  processes such as precipitation and biological
  activities.(CO2 removal)
• Local state and federal government agencies have
  been trying to reduce the quantities of polluting
  materials discharged into the atmosphere.
  Significant reduction for adequately clean air
  will require many years and ENFORCED laws.