Another reason to take the stairs.

Traces of Cobalt 60 have been found in elevator buttons in France. These have been traced back to Indian steel mills. Basically what happens is when Cobalt 60 is unregulated it gets discarded in scrap metal and when melted down finds it's way back into iron and steel products making the products radioactive.

While you probably wont get any over exposure just from pushing the button, I feel sorry for the folks who were installing them and testing the elevators.

Lesson here? 

Buy local. Take the stairs.