It's of some concern, of course. I have family in SF CA, and I've passed on some stuff and urged them to stay away from the beach, pacific seafood etc. I haven't dashed to the S. Hemisphere or anything myself. I've been in Thailand since 3/11, and I even eat seafood when I feel like it... semi-daily, as I believe it mostly comes from Sea of Thailand & Indian Ocean here. So I've prolly been a bit of a sinner here & there wrt Fuku fallout prudence. TH is southwest of JP, and the currents from JP circle around the N. Pacific, the opposite direction from TH. I eat something curry based more days than not, as I love it, and the curcumen in curry (turmeric) is thought to have anti-cancer, even cancer-prophylactic properties. I brush teeth with baking soda & turmeric mix, then swallow it all. My R/O-filtered drinking water is usually spiked with apple cider vinegar... all pH regulating stuff.
But hey, ultimately if I get some terminal cancer one day, I'll give the world of nutritional/herbal (420!) alt-remedies a go, play the results by ear, and if nothing's working I'll just have my affairs in order & off myself rather than any slow painful route to the same place. Main thing is, nothing goes to Western Big Med/Phama (read: dajooz) so they can kill me in the most profitable way.
I learned something from having spent '04 through around '08 or so, worried about "Peak Oil", imminent collapse any second now, Mad Max society during a treacherous die-off etc etc, and oh what a waste of emotional energy! I do hear Rense & others preaching about Fuku as "Extinction Level Event" and so on, but whatever the truth is, I aint gonna let it consume me in worry... that'll gimme cancer faster than a little radiation here & there will! Besides, radiation doesn't even really exist!