Radionuclide levels in drinking water

Looking for a handful ofcountry guidelines for acceptable radionuclide levels in drinking water. The WHO has a range of between 0.2-0.8 mSv and we are trying to benchmark some countries against this, particularlyJordan which has a limit of 0.5 mSv.

Would anyone happen to know of a resource that could provide quick information on the topic?