[Retric]

ED: This is in terms of the New York City drop in violence around 1993.

The data is just not as clear as your suggesting. After controlling for various things there is a percentage of the variation that links back to lead levels, but that does not mean it's the only or even the strongest impact in the raw data. Further, lead usage is linked to other things and as such is not completely independent.

PS: Remember, people move so lifetime exposure get's really hard to track accurately without regular blood tests.

[lostlogin]

I'm struggling to find the other article that covers a broader geographic area, it was posted here last year. This one is a ok http://www.bbc.com/news/magazine-27067615