Average dose by natural radiation: 2,5 mSv/year, with important differences depending on where on the globe one lives.
For example, the proportion of thorium or uranium in the soil results in an exposure of 15 mSv/year in some parts of the Kerala state in India, or of 5 to 10 mSv/year in some parts of Brasil. By way of comparison, the average dose by natural radiation in Belgium amounts to + 2,1 mSv/year.
Total average dose in Belgium:
4,1 mSv/year, of which 51% or + 2,1 mSv of natural origin (radon, cosmic radiation, ...) and 49% of artificial origin (chiefly medical exposure).