‘Higher than normal’ meaning what? You can ingest higher than normal levels of anything of a bad nature, and still do so safely.
Have you ever had Ben & Jerry’s ice cream?
Hard to say what is higher then normal after the government lifts is maximum safe yearly intake levels. The nuke industry regulators in Japan have had to lift many maximum safe levels. And that is understandable considering three whole reactors melted down and at least two explosions occurred. I can give links, but there are literally dozens of them documenting very high levels in Japanese food that are multiples greater then the new higher safe limits.