"Some 45, 000 square kilometers in Western Europe have measurable levels of radioactivity in the soil from Chernobyl above the criterion applied in the former Soviet Union to designate 'contaminated' areas, " said UNSCEAR Secretary Malcolm Crick.
The effects of radiation only start to become clear at high acute absorbed doses of over 1 Sv (100 rem), and even then it is necessary to eliminate other potential causes before radiation can be unequivocally said to be the cause, advised UNSCEAR.