How so? Same as with botox what matters is concentration. And public fear of radiation is significantly overblown compared to what is logically warranted.
We can see this induced fear at work in Fukushima, where they can't dump into ocean water which was filtered from all radioactive isotopes but tritium, even though its concentration is relatively small. For example, if you dump all this water into ocean, it's calculated that in one year an average Japanese will get a dose equal to 0.8 µSv, which is approximately equal to how much you regularly get from natural sources in just 3 hours.
If anything I think that heavy metal poisoning is much more dangerous and nasty. I am quite sure that it has caused orders of magnitudes more damage to the world's population than all human-created radiation combined (not counting the US nuclear bombing of Japan). But you don't hear much about it compared to the damage caused by radiation, do you?
No, people aren’t allowed to return to parts of Fukushima due to contamination. It’s ruined fishing industries because no one wants to buy food from the area.