What types of "gadgets" specifically? Why would there be radiation sources in them? Why would they be in powder form? And why from China specifically?
This is not any kind of common knowledge. Can you point to sources for this? Who considers this "mandatory safety equipment"?
If anything it's impressive that the purveyors of such bracelets and other things would go to the bother of including radioactive material in the first place. They could have just put some ground quartz (i.e. sand) in it and said it was "crystals". No one was going to check, and even if they did, and you couldn't fob then off by saying their test was invalid, like the Batteriser guy tried to do, what would they do about it? Leave you a bad review on Amazon before you rebrand as Engrokoo or something and pop up as a new name?