How does lead toxicity from jewelry happen vs. occupational exposure?
Metallic lead is comparatively inert, but after exposure to air it quickly develops a film of lead compounds, including litharge, $\ce{PbO}$, basic lead sulfate, $\ce{Pb2SO4(OH)2}$, etc. Though these are not very soluble, sweat and bacterial action can convert them to much more soluble compounds.
Lead is also very soft, so touching an article made of lead leaves a residue on the fingers, similar to the way using an aluminum-handled tool leaves the hands covered in gray aluminum and its compounds.
The danger is usually not immediate, but rather the accumulation of toxic lead in the body. However, lead worn next to the skin is steadily abraded. Also, children (and pets) put things in their mouths or even swallow them. Stomach acids do dissolve lead, and there is high mortality in waterfowl from swallowing lead pellets.
This is why lead has no place in play things (or perhaps in most products, since it will almost invariably leach out to poison the environment).
That said, this is an abstract comment, and not to be construed as a way to &quot;safely&quot; use lead in toys.