That chart is brilliant! I'm giving it to our medical physicists. Thanks for that link!
Glad to be of help. The NRC has a "neat" calculator to estimate how much radiation you receive annually.
Most people receive between 3 microSv (1 microSievert = 100 mrem/millirem) and 7mSv. You don't want to receive any more than 50 microSv in a year's timeframe.
To give you an idea of scale, ingesting enough to give you 1Sv carries around a 5% chance of directly causing cancer.
Now, eating pacific tuna (from this article) shows that although the radiation dose has increased, you are still only obtaining an effective dose to that of eating 5% of a banana. Therefore, if you're worried about getting cancer from fish because of zomgFukushima, stop eating bananas. I wouldn't recommend a diet entirely of tuna (mostly because you are more likely to get mercury poisoning anyways...), but don't be scared of the onslaught of negative and false advertising.