A quick google on leather and radioactive decay resulted in this Chernobyl article, it says;
www.fullspate.net...
"And what about the soldiers who worked on the roof of the reactor? 3,600 soldiers worked on the roof to clear the debris and get it ready so we
could build the concrete shield. These guys got it the worst. They had lead vests, but the radiation was coming from below, and they weren't
protected there.
They were wearing ordinary, cheap imitation-leather boots."
"No one was really supposed to go up there. The job was supposed to be done by radio-controlled robots that the Americans and the Japanese gave us,
but the radiation disrupted their electronics and they broke down after a few minutes."
Interesting none the less, but i can't really find much on radioactive decay on other matierals.. i'll keep searching though.