Always late to the party, here it is the 22nd and we just find out that it is Radon Protection Month in America.
Radon is the second leading cause of lung cancer after smoking. Most Radon enters your house through the basement or slab; that is why we say on Planet Green that if you are building a home office, put it above grade.
The only way to find it is to test for it, and if it is in the basement, it is relatively easy to deal with through sealing and ventilation. (You can have testing done professionally or buy a testing kit) Other sources are a bit more problematic.
First place in National Radon Poster Contest by Shana, Age 10, from Georgia
Consumer advocates at Buildclean remind us that it can also come from building materials. Sara Speer Selber of Buildclean writes:
"Certain industries, building materials manufacturers, and resellers would have consumers believe there is absolutely nothing to worry about when it comes to the potential for surface choices such as granite, concrete, or ceramic tile to contribute to indoor radon exposure," said Speer Selber.
"A growing body of evidence indicates that some very popular materials may, in some instances, emit not only radon but gamma radiation. The only way to know is to test the materials in your home environment -- or better yet -- before installing them," she added.
Building a radon-resistant house:
A. Gas Permeable Layer: This layer is placed beneath the slab or flooring system to allow the soil gas to move freely underneath the house. In many cases, the material used is a 4-inch layer of clean gravel.
B. Plastic Sheeting: Plastic sheeting is placed on top of the gas permeable layer and under the slab to help prevent the soil gas from entering the home. In crawlspaces, the sheeting is placed over the crawlspace floor.
C. Sealing and Caulking: All openings in the concrete foundation floor are sealed to reduce soil gas entry into the home.
D. Vent Pipe: A 3- or 4-inch gas-tight or PVC pipe (commonly used for plumbing) runs from the gas permeable layer through the house to the roof to safely vent radon and other soil gases above the house.
E. Junction Box: An electrical junction box is installed in case an electric venting fan is needed later. From EPA
More on Radon in TreeHugger and Planet Green:
What's the 2nd Leading Cause of Lung Cancer in the US?
Home Office Tricks: Watch out for Dangers
Ask TreeHugger: What Do Radon Tests Mean?
GreenBuild: Buildclean is a Breath of Fresh Air
Don't Take it for Granite that Your Countertop isn't Radioactive ...
And from How Stuff Works:
What is Radon?
How Does Radon Get into a Home?
How Do You Test for Radon?
What is the Health Risk of Radon?