How much is dangerous?
Any amount of radiation can be dangerous because it can disrupt normal cell processes. But at low doses, the body can replace any cells that die because of exposure. At high doses, the body can’t replace the dying cells fast enough and tissues and organs may begin failing. To get light radiation sickness symptoms, you would need to be exposed to more than 1,000 mSv of radiation within a short time. The dose from an X-ray is too low to cause radiation sickness, while doses from cancer treatments might be high enough to cause some symptoms. Emissions from cellphones and microwaves are also low.
