Most of us never think about radiation effects except when we need to have a dental or chest x-ray to rule out disease. Also, the sun's radiation affects us daily but we don't pay it much attention until we are faced with a nasty burn. (Not a smart course of action.)
But what about the early days of science and medicine when x-rays were newly discovered? I came across this General Electric 1940s film on German physicist, Wilhelm Röntgen's discovery of x-rays. This educational "infomercial" is interesting AND scary when you think of how little they knew.
Compare that to today's use of medical physics in CT, MRI, and other imaging methods. Progress has been made and medical science has come a long way. Something to think about. Go science!