While Marie Skłodowska's husband, Pierre Curie, died in a traffic accident, she died of cancer. Various sources claim that the radiation she got during their experiments might have contributed significantly to that. Obviously, the effects of radioactivity were not yet known at the time (not even much later).
Today, the acquired dose of the human body is measured in Sieverts, which is essentially the Gray (which is the mass-specific radioactive energy), weighted with the sensitivity of the organs.
Is it known, or at least estimated, how many Sieverts the Curies did get?