Also, humans in general seem to have a rather higher tolerance for radiation, any kind, than people generally assume. Especially if the exposure is relatively short. It can be a gamble, as some individuals react worse than others, but it is not a guaranteed death, or even guaranteed harm, for everybody.

The highest natural radioactive background radiation area on Earth where people live seems to be Ramsar, Iran, 250 mSv per year, when the highest allowed for nuclear facility workers and such seems to be 50 mSv per year, and yet people living in Ramsar, a lot of who have lived there their whole lives, actually seem to have lower number of lung cancer cases per year than people living elsewhere, and otherwise no higher number of anything you usually connect to radiation exposure.