Have a read up on radiation hormesis. It looks like small doses might be beneficial. The linear no threshold model is all fine and good at high doses, but low down the data is poor. <a href="http:&#x2F;&#x2F;www.ncbi.nlm.nih.gov&#x2F;pubmed&#x2F;15673519" rel="nofollow">http:&#x2F;&#x2F;www.ncbi.nlm.nih.gov&#x2F;pubmed&#x2F;15673519</a>