Air Pollution

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Air Pollution

• The contamination of the atmosphere caused by
  the pollutants from human and natural resources.

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Primary Pollutants

• Put directly into the air by human or natural
  activity
• Examples carbon monoxide, dust, smoke, chemicals
  from paint and other substances

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• Give 3 primary pollutants from natural sources.

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• Smoke, dust, sea salt, carbon monoxide, chemicals
  from paint and other substances

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Secondary Pollutants

• Form when primary pollutants react with other
  primary pollutants or with naturally occurring
  substances, such as water vapor.
• Examples ozone, smog

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Ozone

• - Produced when sunlight reacts with vehicle
  exhaust and air

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Smog

• Forms when ozone and vehicle exhaust react with
  sunlight

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Sources of Human- Caused Air pollution

• Industrial air pollution
• Examples
• -industrial plants and electric power plants burn
  fossil fuels, such as coal to produce energy
• - Oil refineries, chemical manufacturing plants,
  dry- cleaning businesses, auto body shops

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• Indoor Air Pollution
• Ventilation- the mixing of indoor air with
  outdoor air which can reduce indoor air pollution

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Acid Precipitation

• Rain, sleet, or snow that contains a high
  concentration of acids

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Effects of Acid Precipitation

• Soil acidification- acidity of soil increases
  causing nutrients needed by plants to be washed
  away.
• Increased acidity causes aluminum and other toxic
  metals to be released and absorbed by the roots

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• How does acid precipitation affect plants?

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• Acid precipitation may decrease the soil
  nutrients that are available to plants.

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• 2. Acid shock- rapid change in a body of waters
  acidity
• Can cause large numbers of fish to die
• Can affect the delicate eggs of fish and
  amphibians

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To reduce effects of acid precipitation

• Spray powdered lime on acidified lakes in spring.
• Lime- a base, neutralizes the acid in the water

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• Why is powdered lime sprayed on lakes in the
  spring instead of the fall?

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• Powdered lime is used to counteract the effect of
  acidic snowmelt from snow that accumulated during
  the winter.

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The Ozone Hole

• Ozone- O
• Hole in the ozone layer
• Allows more UV (ultraviolet radiation) to reach
  the earths surface
• Damages genes and causes skin cancer
• Thin over the Antarctic regions, during spring

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Cause of Ozone Hole

• Chemicals called CFCs caused ozone to break down
  into oxygen, which does not block the suns
  harmful rays.

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• CFC molecules can remain active in the
  stratosphere for 60 to 120 years. So CFCs
  released 30 years ago are still destroying the
  ozone today. Thus, it will take many years for
  the ozone layer to completely recover.

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Air pollution and Human health

• HealthShort-term effects headache nausea
  irritation of eyes, nose, and throat coughing
  upper respiratory infections worsening of asthma
  and emphysema
• Long-term effects emphysema lung cancer
  permanent lung damage heart disease

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Cleaning Up Air Pollution

• Clean Air Act- a law that gives the EPA
  (Environmental Protection Agency) the authority
  to control the amount of air pollutants that are
  released from cars and factories.

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• Scrubber- used to remove some pollutants before
  they are released by smokestacks

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Allowance Trading System

• Establishes allowances for a certain type of
  pollutant. If companies exceed the allowance,
  they must buy additional allowances or pay a fine.

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Reducing Air Pollution from Vehicles

• Cars that run on fuels other than gasoline
• Example hybrid cars use gasoline and electric
  power
• - carpool