[ RadSafe ] C h e m o t o x i c i t y of thorium?

[franz.schoenhofer at chello.at]

Dear RADSAFErs,

I stay now for a few months in Poland, working on a project on NORM in drinking water. Because of numerous discussions inspired by the fact that the European Union set only a radiation specific limit for radionuclides including "uranium", though uranium is far more chemotoxic than radiotoxic I wonder, how the situation is with thorium. I have not found anything useful about chemotoxicity of thorium in comparison of its (high) radiotoxicity.
Any information, any links available?

Best regards,

Franz