http://lindaprout.com/nodietblog/2011/03/14/radiation-protection/



and from Dr Veronica Waks on what to expect from the nuclear blow over

http://healthandbeautydoc.blogspot.com/2011/03/protect-yourself-now-from-japan.html 


Again, I'm not an expert on this. But google and do your own research and do what feels appropriate.