Like John said, the small percentage of lead is to improve machineability. There is lead in all kinds of stuff that's why Mom always said to wash your hands before eating.
California sued the key manufacturers over the lead content in the keys you have in your pocket. 1.5% was okay, but 2.0% has to be labeled.
There is nothing wrong with limiting our exposure to lead, but it's not something that I'm very concerned about.