There used to be cadmium in just about all printing papers - not only the contact papers. Any famous photo printed more than ten years ago (or on more than ten years old paper) is likely to have been printed on cadmium-bearing paper.
The "new" cadmium-free emulsions caused a minor revolution in lith printing, as all papers suddenly behaved completely differently.
My entry in the Traveling Portfolio was printed on old "New Oriental Seagull" which contained cadmium. The recent stuff (with the big black circle on) does not. At least so I have been told.