How about Chicago: > The biggest reason is that essentially Chicago and other cities around Illinois required the use of lead service lines all the way until 1986, long after it was recognized that lead was poisonous and other cities had stopped using it. A decade after other cities had stopped using it Chicago and other cities in Illinois were not only using it but requiring the use of lead long after everybody else…
It seems like the lead blood level indicator has been removed from this site, but a friend showed me this map of homicide rates vs one with lead levels from 18 years prior[0] and there was a pretty strong correlation. Obviously there are confounders, but Kevin Drum’s decade old article positing that lead was a major contributor to the crime wave and subsequent reduction is pretty compelling. [1] EDIT: aside, but mayb…
https://annalsofglobalhealth.org/articles/10.5334/aogh.2754/