Why was Kryptonite introduced to the Superman series

It was back in June of 1943 when “Kryptonite” was introduced to the Superman radio series, as the actor Bud Collyer was about to take few days off.

The radioactive element “Kryptonite”  played a part during the program “The Meteor from Krypton”.

After 1949 “Kryptonite” was incorporated to other comics, as well and due to its dangerous nature (Superman’ s weakness) it has also been used as a synonym for Achilles’ heel.