help with display screen users

hoping someone can help, friend of mine works for a national newspaper (as there nurse) shes got a girl who has been diagnosed as leukemia, this girl is convinced that she has got it from being in front of a screen all day, we cant find any research that will convince her otherwise anyone help here. We know that she needs somthing to blame but shes scaring all the other D.S.E. users

thanks if you have research can you quote reference and well try and get it