Radon is not (ionising) radiation, it's a radioactive substance! Fear of radiation is indeed irrational, because the radiation most likely to give you cancer i

Radon is not (ionising) radiation, it's a radioactive substance! Fear of radiation is indeed irrational, because the radiation most likely to give you cancer is sunlight! Fear of radioactive substances is very rational. The danger of radioactive material is that it can be consumed, and so bypasses the protection of the only organ that has actually evolved substantial defence against ionising radiation (your skin). As it hangs around for an indeterminate amount of time you have little way of knowing how much radiation you have absorbed.