This is news to me. Apparently, in the US, dirt bikes and ATV's intended for kids under 12 are now banned due to excessive lead levels.
This is bizarre. I am all for keeping kids safe, but this is unreasonable.
Eliminating lead from childrens toys, that are often licked/chewed by kids is a great idea, since lead is a neurotoxin when ingested in sufficient quantities.
But are kids going to lick/chew their motorbikes? I don't think so. Frankly, kids face much more serious risks from reckless riding etc. Fretting about lead levels is entirely misdirected.
More info:
http://www.ama-cycle.org/news/story.asp?id=1275