Do you choose what family you're born into?
How exactly does that make you no longer responsible for your actions? Are you saying that if you're born into a poor family then you have no choice but to murder, rape and steal? What is your point?
Children aren't responsible for their own lead exposure.
My original post is referring to competent adults, not children or the mentally disabled. I grant that if you are a retard, you aren't necessarily in control of your actions. Everyone else still has to take personal responsibility.