The dose of radiation expected to cause death to 50 percent of an exposed population within 30 days (LD 50/30). Typically, the LD 50/30 is in the range from 400 to 450 rem (4 to 5 sieverts) received over a very short period.

How many sieverts of radiation can kill you?

For example, a single one sievert (1,000 mSv) dose causes radiation sickness such as nausea, vomiting, hemorrhaging, but not death. A single dose of 5 sieverts would kill about half of those exposed to it within a month.

How many milli Sieverts is lethal?

Absorption of a dose between 0.5 and 2 sieverts (Sv) will result in a light reaction involving nausea, asthenia and vomiting between 3 and 6 hours after the exposure. Somewhere between 4 and 4.5 Sv lies the so-called DL50 level, which is the point at which exposure will be fatal in 50% of cases.