Radon Information Links
There are a lot of great facts and links. See "Publications" at the top of the page for all rof the EPA's radon related publications.
AARST is the radon industry association. AARST is a voluntary professional association, which serves those individuals engaged in the research, testing, measurement, and remediation of radon.
A nationally recognized certification program for radon professionals throughout the country.
A national certification program for radon professionals.
Here is the direct link to all of the state Indoor Air Quality Programs.
This site has all of the need to know information concerning our water supplies including, waterborne radon.
"Radon In Earth, Air, and Water" site has some good old "nuts and bolts" information on radon in air and radon in water. They have their radon publications available here also.
The stated summary is "the Iowa Radon Lung Cancer Study found excess risks of 0.50 for exposures that are roughly equivalent to 15-years spent at an average radon exposure of 4 pCi/L. The results suggest that residential radon exposure is a significant risk factor for lung cancer." The key author of this study is Dr. R. William Field.
Dr. R. William Field in conjunction with Virtual Hospital presents a lot of useful information on radon, radon occurrence and radon health risk.