Cosmic-radiation exposure

location mean dose in millisievert (mSv)* per year

sea level, temperate zone 0.20–0.40

1,500 metres 0.40–0.60

3,000 metres 0.80–1.20

12,000 metres 28

36–600 kilometres 70–150

interplanetary space 180–250

Van Allen radiation belt (protons) \\<15,000

single solar flare (protons and helium) \\<10,000

*Millisievert is a radiation dose-equivalent unit: it corresponds to a dose equivalent in biologic effectiveness to 10 ergs energy of gamma radiation transferred to one gram of tissue.