Healthy radiation????

[Astronuc]

This subject came up in another forum, where I pointed out that the younger the organism, the more risk radiation poses - even X-rays (which are low energy - few eV to 100's keV).

Fetuses and children have very high rates of cell division (mitosis) and they are particularly vulnerable to radiation.  One change in the DNA, near the beginning, will have profound consequences for the organism during later stages of development.