No serious radioactivity affecting anyone outside of the immediate vicinity of the Fukushima complex yet.

Were east coast fish stocks affected by Three Mile Island? Or Mediterranean fish by Chernobyl*? It pays to keep speculations within context.
*(Fish in lakes near Chernobyl may have measureable radioactive caesium, but dilution in oceans or large seas would render the amount immeasurable).

One gets as much radioactive bang from one CT Scan as from a year's exposure near the Fukushima complex at present rates.
Comparable rates- A whole body scan exposes one to 720 mSv/ hour and the highest measured at Fukushima complex was 420 mSv.
Dr. Jeffrey R. Toney, reported in http://scienceblogs.com/deanscorner/2011/03/fukushima_radiation_levels_or.php

(Radioactive iodine has a half life of 8 days but the caesium is much longer (forgotten, but in press items recently)). I think Charlie could fill this in.

If the Fukushima complex can be stabilized in the next couple of weeks, no sky is falling scenario need be invoked.