Work out radiation dose (sievert) instantly with clear inputs, formula shown and shareable results.
Absorbed dose in gray measures energy deposited; equivalent dose in sievert weights it by how damaging the radiation is. Alpha particles carry a factor of 20 because they deposit energy densely. Multiplying again by the tissue weighting factor gives the effective dose - 2 mGy of gamma to the lung (wT = 0.12) is 0.24 mSv effective.
Equivalent dose
H = D x wR
Effective dose
E = H x wT
About 2.4 mSv worldwide from cosmic rays, radon and natural radioactivity, though radon-prone areas can be several times higher.
Because it deposits its energy over a few tens of microns, causing dense clusters of DNA damage that are far harder to repair.