I think unfortunately this would open the door for bad actors too. Taking old outdated phone batteries and combining them would allow for some crazy things that could do mass harm. Even smoke detectors with Americium can be gathered and dissected to radiate a small neighborhood or inact terrorism. Additional reading: en.wikipedia.org/wiki/David_Hahn

The whole story of why we use Americium in detectors is an interesting one in itself. youtu.be/DuAeaIcAXtg one of my favorite long form nerdy youtube channels.