Examples of strong doses
The sievert, as a dose unit, appears to represent a strong exposure as can be seen from this sample of exposures considered to be high. The highest dose represented here - 20 Sv - is that suffered by one of the two workers of Tokaimura who died after receiving 4 times the lethal dose. Survivors of Hiroshima were exposed to varying doses, ranging from a few millisieverts (mSv) to 500 mSv. On average, the Chernobyl liquidators received around 100 mSv. More exposed, the group of firefighters received 250 mSv on average, 163 of them exceeding a dose of 1 Sv.