The current CDC standard is zero lead for children and childbearing women.
That comes from finding clinical evidence of damage when they are down at the limits of what they can measure accurately. That standard poses a very significant question: Does lead intake in adult males follow different patterns or can we simply not measure that effect separately from the rest of the damage? The science has steadily decreased the standard for everyone, including adult males, so I wouldn't be surprised to see that trend continue. Substituting lead for calcium is where the problems come from.
