It's even worse than that, I think. I may have missed it since I just skimmed that document, but I don't think it covered violent crime.
It has been shown rather conclusively that overexposure to lead in childhood leads to an increase in violent crime in adulthood. Banning leaded gasoline was the single most significant cause of the large decrease in violent crime in the US in the latter part of the 20th century. Here's one story on this [1]. Cites to peer reviewed journals are available from Wikipedia [2].
