There was a BBC Documentary on a couple of years back about the benefits of (low-level) radiation on health and how the hysteria regarding radiation has been completely overblown. For instance, they took a sample of rodents living in parts of the United Kingdom and some living in the so-called "contaminated zone" around Chernobyl and they found out that the Chernobyl rodents were actually far healthier and disease resistent than their British counterparts.
Allied to this there was a study that showed there was no direct link between working as a Pilot and higher cancer rates. Interestingly they also showed a map of cancer rates across the USA and plotted it against a map of the USA in terms of areas of highest background radiation. There was a directly inverse relationship between levels of background radiation to cancer rates showing that background radiation (in this instance) was beneficial to health.
The main message was that radiation was (until you got to a certain level) beneficial and we needent be so worried about its effects.