To my knowledge there were no known cases of secondary transmission. I don't know if it's biologically even possible in this case. The issue isn't that they were getting radium on their lips, it was that they were getting it inside their mouths (they were sticking the brush nibs in their mouth to "sharpen" them), in small doses, over a long period of time. Once inside the mouth it was transmitted into other parts of the body. That is not the sort of thing that is easily transferred to another person. It is not impossible for someone to transmit radioactive contamination to other people, but it requires massive doses usually to be an issue (this comes up when people are given certain types of radiation therapy), and the substances need to be excreted by the body in some way (e.g., through sweat, vomit, feces, whatever).