I felt like your program on Fukushima was more confusing than clarifying. There is no healthy dose of radioactive isotopes from nuclear reactors. All of them are dangerous and damaging to life. Take a look at some of the results of radioactivity from Chernobyl:
You can talk about mercury in fish but it doesn't produce the same results as man-made radioactive isotopes. I suggest you do more research and actually look for scientific opinions about how dangerous these substances are to life.