The physics and physiology of radiation exposure seem to be quite complicated. I can't really answer your question, I'm very far from qualified to do so, but again _according to Wikipedia_ the short term effect of 0.2 Sv per day, let alone a year, seems to fall into the "no effect" category[1]. And according to this[2] post on Boingboing, the long term effect may not be as bad as one might think either.

[1] http://en.wikipedia.org/wiki/Sievert#Symptom_Benchmarks [2] http://www.boingboing.net/2011/03/14/radiation-dose-and-r.ht...