I liked the link from angry bear and the analogy that persons killed in car accidents were killed by seat belts as they were all wearing them.
I have an excerpt from an American research that's states that lead doesn't break down once in the body.
You would need to Google a few lines but you can find it.
37 Physicians must understand that air-weapon pellets carry a propensity to embolize once in the bloodstream.34,39 (The old fear of lead poisoning from a retained air-weapon pellet appears obsolete, as the modern alloy composition of the ammunition does not elevate serum lead levels
Repariere nicht, was nicht kaputtist.