Can thorium kill you

Answer 1

Thorium is only weakly radioactive, emitting alpha particles which can barely penetrate human skin, thus exposure to it externally could not kill you. Thorium could be dangerous inside the body, where it could trigger cancers in internal organs. A bigger danger is that thorium decay gives rise to radioactive radon gas which could conceivably build up to a dangerous level if stored in a confined space. As a nuclear fuel, thorium is very much safer than uranium and plutonium. Thorium is present in most soils in fairly significant quantities. Overall, it is very very unlikely to cause you any harm whatsoever unless perhaps you work with it routinely without taking any precautions.