Few issues in our uncomfortably complicated high-tech modern world are so muddled as that of radiation hazards. The confusion stems partly from the emotionally charged politics surrounding any subject associated with the word ``nuclear'' -- which in turn is the result of the brutalizing terror of nuclear war that has infected the psyches of several generations of Cold War veterans -- and partly from ignorance and misunderstanding of what radiation does and how it can be harmful -- which in its own turn is the result of decades of gleeful indulgence in the thrills of grade-B sci-fi horror films. Moreover, most people seem quite content with their fantasies and ``good vs. evil'' decision-making strategies, so don't expect a deeper understanding to enhance your popularity! Nevertheless, knowledge is power and someone has to know what's going on, so it looks like you're it. Let me tell you what I can.
Caveat! I encourage you to distrust everything I say (and everything anyone else says) on this subject until you have seen (and believe) the data for yourself. Like most people, I am not a scholar or even an expert in the field of radiation hazards, just an amateur with strong convictions which will distort my presentation of the evidence; my only excuse for subjecting you to my opinions is that everyone else seems to be so timid about expressing any ideas on this topic that the only information you are likely to get elsewhere (without determined effort on your part) is even more politically motivated and less reliable than mine, which I acquired through informal discussions with various people who do have legitimate professional credentials. If you have studied radiobiology (as many Physics 200 students have) you will probably find my descriptions of DNA strand-breaking pathetically naive, but I hope the ``overview'' presented here will still be of some use.