Answer:
There is NO SAFE LEVEL radiation exposure, I am going through this with my son right now. After a bout with Cancer when he was 8 years old, and all the chemo and radiation therapy he was given the cancer free status at 11 years old. We have kept a watchful eye on his health for the last 24 years.
Dec. of 2009 he was given the news that he has thyroid cancer the Doctors have said this was most likely caused by the radiation from his "Childhood Cancer Treatments". Yes we have had 24 years with out this mess but Why didn't anyone tell us before that this was a danger. So basically his cure has caused this second bout of cancer.
After months of researching my wife and I found a New Company that offers an All Natural Product Line that has a Heavy Metal Detox as part of their health program. Our website is up and running with these products listed, you can see it here http://xrl.us/qsystem copy and past it into your top nav bar. Before you get some more bad news look at what your doctors may failed to tell you.
[update by different user]
Radiation is found anywhere and everywhere, this is called background radiation. Examples of this may be found in the potassium of bananas (and have bananas ever given anyone cancer?) the sun provides radiation, which is of course buffered by the o-zone. Even more radiation is put onto earth which is known as cosmic radiation. All in all, the average dose of radiation that a person will "intake" per year is 360 millirems.