Where does radon gas come from ?
Three Radon Sources
- Soil or Bedrock – The Typical Culprit 80-‐90%
- Building Materials – Sometimes but not Typical
- Water -‐ Rarely
Soil/Bedrock are the Primary Sources of Radon
Radium source must be near air or water in the soil pores
SOIL PORES AIR SPACE IN THE DIRT easy soil gas transport
Examples of Porous Soils/Rocks: shale, glacier-‐ground granites ,limestone
Extreme Variations from100 pCi/L -‐100,000+ pCi/L
If your neighbor has high Radon it does not mean that your home will have it too
Factors of Radon Accumulation
- Radon is constantly entering buildings and can accumulate to elevated levels due to:
- Strength of the Radium Source
- Building Materials & Construction design
- Ventilation System Adequacy
- Indoor Air Quality, Temperature, & Humidity
- Weather
- Pathways Into the Home
Radon Physics: Radiation, Radioactivity and Radon
Radon GAS:
- Tasteless
- Naturally occurring
- Decays into Radioactive decay products
- Radon Decay Products = RDPs
- Inert or Noble gas (does not chemically react)
- Colorless
- Odorless
Alpha Radiation
- Greatest risk associated with radon/RDPs
- Mostly a problem in the lungs
- Low penetrating power
- Can cause great tissue damage
- Alpha RBE (Relative Biological Effect) is 20 times greater than Beta or Gamma radiation
Radon Decay Products
- Source of cell damage in lungs
- Have static charges
- Chemically reactive
- Solid particles
- Heavy Metals
- Easily attach themselves to solid objects such as dust, smoke, walls, floors, clothing, or any other object (plate out).
