Well shivling for some is an emotion but if science worshipers starts seeing from their eyes then its a rock made particle.. anyways lets talk about what is a radioactive element? It is basically an element which has heavy atoms they got heavy atoms because of the neutrons in their nucleus later they split into smaller nucleids which are more stable and then it makes a nuclear reaction. During this reaction many energies placed like alpha, gamma and beta particles.
Shivlings are made up of stones. For radioactivity a substance should be of uranium and thorium.
Some people say milk and bael leaves occur radiation as milk absorb the radiation
Radiation gets into the milk because it falls on grass eaten by cows. The milk doesn't absorb radiation.
There are no scientific proven source that bael leaves can pass radiation too..