Actually, Professor Hamilton in Smallville(played by Joe Morton), after all his time being around the kryptonite in his research on it and its effects on biology around it. Was succumbing to radiation poisoning before dying from a humungous exposure to it.
Likewise, it was revealed in Action Comics#600, that the krytonite ring Lex Luthor wore to dick around with Superman. Ended up giving the crumy crook radiation poisoning as well. Causing him to loose his hand, and cancer to boot.Which lead him to fake his death, and have his brain transplanted in a younger cloned body. Which for a while he passed himself as Lex Jr. until Lois Lane dug up the truth.