Everyone in the world is continually exposed to background radiation. That level has gone up considerably since the US began testing atom bombs in the atmosphere. The current AVERAGE level in THE WORLD is about 3 millisieverts per year. In the US it averages about 6 mSv per year (depending on where you live; it might be much higher.)
By comparison, these days:
One chest x-ray delivers 20 μSv = .02 mSv.
On the other hand, one CT scan delivers from 1 to 20 mSv.
Everyone in the world is continually exposed to background radiation. That level has gone up considerably since the US began testing atom bombs in the atmosphere. The current AVERAGE level in THE WORLD is about 3 millisieverts per year. In the US it averages about 6 mSv per year (depending on where you live; it might be much higher.)
By comparison, these days: One chest x-ray delivers 20 μSv = .02 mSv. On the other hand, one CT scan delivers from 1 to 20 mSv.
https://en.wikipedia.org/wiki/Background_radiation