[tim333]

I tried googling the risk and it's all a bit inconclusive but:

>The linear no-threshold model is disputed by several health organizations, including the American Association of Physicists in Medicine and the Health Physics Society, both of which concluded that cancer risk estimation should be limited to doses greater than 50 mSv. Both organizations state that risks from doses below this threshold are too small to be detectable and may be nonexistent.