What you fail to include in your discussion of risk is probability. You only discuss potential consequence, but that is not enough to evaluate a risk. And in absence of knowing probability, risk perception is skewed, a central element to my point.
A discussion of probability is only possible when the quantities of radionuclide effluent from the Fukushima disaster is generally available. I will remind you that the Japanese government has a media blackout so hard data on what type and how much radionuclides were released is not available. You are welcome to contribute that data to the discussion so probability can be assessed.
It is pointless complaining to me about the lack of data as I would also like to see it. Until such data is made available then we will just have to deal with uncertainty. It is safe to say though it is more than nothing.
The data for exposure risk is known, it generally shows extremely low probability of negative health impacts. But most folks don't realize just how low that is compared to many of the things they do daily.
The point is not that it is low, it is that it exists at all and how much increase in risk we can expect as the radionuclide effluent is absorbed into the foodchain.
By not riding in a car, you are not exposing yourself to the risk of death or injury by car accident. But you do it anyhow.
A more honest comparison would be a risky activity like bungee jumping, an unnecessary risk that you choose as compared to driving car which is a necessary risk you control.
Until we get data on what and how much radionuclides were released we won't be able to quantify the risk. If you're happy to eat Fukushima food, go ahead, you'll probably be ok.