Indoor Air Pollution

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Indoor Air Pollution

• Radioactivity from Radon Gas
• Group members ???,???,??

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Outline

• Introduction
• Where does radon come from?
• How does radon get inside buildings?
• The level and distribution of radon
• The Risk of Living With Radon
• Reducing Radon Risks

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Introduction

• Although pollutant concentrations vary
  significantly from building to building, the
  levels of some common air pollutants often are
  greater indoors than outdoors. Since most people
  spend more time indoors than outdoors, exposure
  to indoor air pollutants is an important
  environmental problem.

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Whats indoor air pollution?

• Indoor Air Pollution is the term used to
  describe the amount of contaminants in the air
  inside a building from sources such as cigarette
  smoking, fuel combustion for heating or cooking,
  certain wallboards, carpets, or insulation as
  well as the geology of the area (radon in soil or
  rocks beneath the structure).

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Whats radon(?)?

• Radon is a naturally-occurring radioactive(????)
  but inert(???) gas part of the decay chain that
  starts with uranium(?) and ends with plumbum (?).
  

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Property of Radon

• Single atom gas
• Inert, colorless, odorless at ordinary
  temperatures
• Melting point 202 degrees K
• Boiling point 211 degrees K
• Atomic radius 1.34 angstroms (the heaviest known
  gas)
• Half-life 3.8days

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Where does radon come from?

• Natural source
• Earth and rock beneath home
• Well water
• Outdoor air
• Artificial source
• Daily life materials leather low density
  plastic (like plastic bags, etc.) paints
• Building materials gypsum board (sheetrock),
  concrete block, mortar, sheathing paper
  (tarpaper), wood paneling, and most insulation.

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• Some uranium is present in all earth materials.
• On continental surfaces the rocks, sediments and
  soils typically contain between 1 and 3 parts per
  million (abbreviated ppm) of uranium. Some earth
  materials may have more.

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How does radon get inside buildings?
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Cavities inside walls
Gaps around service pipes
Cracks in solid floors
The water supply
Construction joints
Gaps in suspended floors
Cracks in walls
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Soil

• Radon from soil gas is the main cause of radon
  problems.
• How much of radon reaches the surface depends on
  the uranium content of the underlying earth
  materials together with their depth and
  permeability (that is, the presence of fractures
  and interconnected pore spaces that act as
  conduits for radon).
• Enter the lowest level of a building using
  whatever pathways are available.

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• For structures with basements or slab-on-grade
  foundations, the entry points include
• Cracks and pores in floor slabs, walls, and
  floor-wall joints
• Openings around sump pumps, floor drains, and
  pipes penetrating floors and walls.

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• Structures with a crawl space between the ground
  and lowest floor level may be less vulnerable to
  radon, which tends to escape to the outside air
  when appropriate vents are installed, but can
  still admit some of the gas through cracks in the
  flooring.

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Water

• Radon can also enter into homes through the water
  system.
• This is mainly true for houses in which ground
  water is used as the main water supply.

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• Small public water works and private domestic
  wells often have closed systems and short transit
  times that do not allow radon to decay to
  harmless by-products before entering a home.
• Once inside, radon escapes from the water to the
  indoor air as people take showers, wash clothes
  or dishes, or otherwise use water. The areas most
  likely to have problems with radon in ground
  water are those with have high levels of uranium
  in the underlying rocks.

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• Water in rivers and reservoirs usually contains
  very little radon, because it escapes into the
  air.
• Thus homes that rely on surface water usually do
  not have a radon problem from their water.
• In big cities, water processing in large
  municipal systems aerates the water, which allows
  radon to escape, and also delays the use of water
  until most of the remaining radon has decayed.

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The Average Level of Radon Found in a Home

• Based on a national residential radon survey
  completed in 1991, the average indoor radon level
  is about 1.3 picocuries(???10-12Ci) per liter
  (pCi/L) in the United States. The average outdoor
  level is about 0.4 pCi/L.

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The safe level of radon

• There is no safe level of radon--any exposure
  poses some risk of cancer.

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Zone 1 counties have a predicted average indoor
radon screening level greater than 4 pCi/L (pico
curies per liter) (red zones) Zone 2 counties
have a predicted average indoor radon screening
level between 2 and 4 pCi/L (orange zones) Zone
3 counties have a predicted average indoor radon
screening level less than 2 pCi/L (yellow zones)
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The Risk of Living With Radon

• Radon gas decays into radioactive particles that
  can get trapped in your lungs when you breathe.
• As they break down further, these particles
  release small bursts of energy. This can damage
  lung tissue and lead to lung cancer over the
  course of your lifetime.

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• Smoking combined with radon is an especially
  serious health risk.
• Children have been reported to have greater risk
  than adults of certain types of cancer from
  radiation, but there are currently no conclusive
  data on whether children are at greater risk than
  adults from radon.

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Radon Risk If You Smoke/Never Smoke
Radon Level If 1,000 people who smoked were exposed to this level over a lifetime... If 1,000 people who never smoked were exposed to this level over a lifetime... WHAT TO DOStop smoking and...
20 pCi/L About 260 people could get lung cancer About 36 people could get lung cancer Fix your home
10 pCi/L About 150 people could get lung cancer About 18 people could get lung cancer Fix your home
8 pCi/L About 120 people could get lung cancer About 15 people could get lung cancer Fix your home
4 pCi/L About 62 people could get lung cancer About 7 people could get lung cancer Fix your home
2 pCi/L About 32 people could get lung cancer About 4 person could get lung cancer Consider fixing between 2 and 4 pCi/L
1.3 pCi/L About 20 people could get lung cancer About 2 people could get lung cancer (Reducing radon evels below 2 pCi/L is difficult.)
0.4 pCi/L About 3 people could get lung cancer (Reducing radon evels below 2 pCi/L is difficult.)
Note If you are a former smoker, your risk may be lower. Lifetime risk of lung cancer deaths from EPA Assessment of Risks from Radon in Homes (EPA 402-R-03-003). Comparison data calculated using the Centers for Disease Control and Prevention's 1999-2001 National Center for Injury Prevention and Control Reports. Note If you are a former smoker, your risk may be lower. Lifetime risk of lung cancer deaths from EPA Assessment of Risks from Radon in Homes (EPA 402-R-03-003). Comparison data calculated using the Centers for Disease Control and Prevention's 1999-2001 National Center for Injury Prevention and Control Reports. Note If you are a former smoker, your risk may be lower. Lifetime risk of lung cancer deaths from EPA Assessment of Risks from Radon in Homes (EPA 402-R-03-003). Comparison data calculated using the Centers for Disease Control and Prevention's 1999-2001 National Center for Injury Prevention and Control Reports. Note If you are a former smoker, your risk may be lower. Lifetime risk of lung cancer deaths from EPA Assessment of Risks from Radon in Homes (EPA 402-R-03-003). Comparison data calculated using the Centers for Disease Control and Prevention's 1999-2001 National Center for Injury Prevention and Control Reports.
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• EPA (Environmental Protection Agency ?????)
  estimates that radon causes thousands of cancer
  deaths in the U.S. each year.

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Reducing Radon Risks
There are two ways to protect your family from
Radon.
First, the hard way
Holding Your Breath
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Lower the Radon Level in Your HomeYour Family
Will Breathe A Lot Easier.
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How to Lower the Radon Level

• The most effective way to lower the radon level
  is set a vent pipe system and fan, which pulls
  radon from beneath the house and vents it to the
  outside. 

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• There are also other ways
• Test your home for radon.
• Be careful when you choose building materials.
• Fill the gaps and cracks in the ground, floor,
  and walls. Pay more attention to the basement and
  the first floor where there is a high level of
  radon.
• Dont smoke in the room, especially the one for
  children and elders.

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Thank you!

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