If I'm reading that map right, there isn't a lot of radioactivity there.
Becquerel per cubic meter????? What the hell kind of radiation measurement is that??? I've already had to learn about rads, rems, and sieverts. Now I've got to go look up Becquerels, too?????
Here's an explanation.
It's just a unit of measurement. Like Sieverts, I don't like it. It's uncommon and not easily digested by the public.