Gun crime and lead poisoning – a link?

No, not the kind of lead poisoning that comes from getting shot.  A Milwaukee report suggests a different kind of linkage.

More than half of the people who were perpetrators or victims of gun violence in Milwaukee in recent years had elevated blood lead levels as children, according to a study released Friday by the University of Wisconsin-Milwaukee.

The study of nearly 90,000 residents, conducted at the University’s Joseph J. Zilber School of Public Health, suggests a link between early childhood lead exposure and gun violence in later years.

. . .

Lindsay R. Emer, the study’s lead author … said that while the study was not able to definitively prove cause and effect, the link is striking:

According to their findings, 56% of the shooters and 51% of the victims were found to have blood lead levels equal to or greater than the recommended limit of lead exposure of 5 micrograms per deciliter.

. . .

The study follows a consistent vein of prior research connecting lead exposure and violence:

Researchers at Harvard University and the University of California Berkeley published a study in 2016 that concluded that cities that used lead water pipes had homicide rates that were 24% higher than cities that did not.

Two researchers published a paper in 2017 for the National Bureau of Economic Research that studied the link between lead exposure and juvenile delinquency and found that as blood lead levels increased, so did the probability of suspension from school.

. . .

Bruce Lanphear, professor of health sciences and epidemiology at Simon Fraser University in British Columbia, described lead exposure in children as insidious.

“If it’s not overt poison, one of the challenges is you don’t really see acute symptoms,” he said. “You do see symptoms more like acting-out type behaviors: ADHD type behaviors, problems with schoolwork, risk-taking behaviors, impulsive behaviors in kids, delinquency in kids.”

Those behavioral challenges, he noted, don’t just disappear once someone turns 18.

“Conduct disorder in children matures into delinquent and sometimes even criminal behavior,” he said.

There’s more at the link.

I’d be interested to see this study correlated with others concerning ethnic groups, education levels, socioeconomic “class”, location (e.g. whether or not living in a specific suburb or area is likely to lead to a greater level of delinquency), etc.  If it can be shown that lead poisoning is a definitive, across-the-board factor in youth crime, particularly involving firearms, it may be a valuable step forward in finding new ways to combat that scourge.  Heaven knows, restrictions on firearms have done nothing to stop it!



  1. I doubt their is a correlation, unless the lead causes people to continuously vote for losing politicians, and corruption.

  2. I'm going to go with the theory that this is a non-causal, parallel relationship and that single parent households, family values, economics, generations living on the dole, drug use, and education all are much greater contributors.

  3. This reminds me of a study which predicted a drop in crime as the people who'd been breathing the air while we still used tetraethyl lead as an octane booster grew out of their peak criminal years.

    A drop in crime coincided with their predictions, but it was a weak correlation.

    I wonder, after reading this, if the kind of poisoning we see here that increases violence also makes for poor parents and if lead pipes are prevalent in areas of distinct "vibrancy".

  4. I wonder if the houses they grow up in are older and more poorly maintained – which to me cries out lead paint exposure.

    Metallic lead itself, and even lead pipes themselves, are not a health hazard – what IS a health hazard is organic lead compounds, such as found in leaded gas or lead based paint.

    *Lead pipes can become a problem if the water flowing though them has chemical that react with the lead and create organic lead compounds, particularly if there is an abrupt change in water sources, such as happened when Detroit cut off Flint from their water supply and Flint had to suddenly change to a new supply.

  5. Interesting, and I think a bit of a reach… If this were true, all of us old farts would be shooting people left and right, since we grew up in houses with lead pipes and lead paint on the walls.

  6. Yeah, no. Else Central and South America, Africa and the Middle East all have exposed lead veins that water runs through it and have had since the dawn of time.

    What next? Greens and ham cause violence? Cornbread? Non-AC living conditions?(well, actually, that one actually has some merit.)

    The causes of violence can be linked to nature, but genetically, not environmentally poisonous. Yes, some people are born bad.

    Then there are those that are raised bad and the surrounding nurturing/lack of nurturing that develops it. Microchanges in lead or other contaminates not so much.

    Hey, researchers! Try paying attention to the real reasons violence exists amongst certain cultures. Or is that too un-politically correct for ya?

  7. So, there is a correlation. But it is admitted that causation cannot be proven. At least someone admitted that correlation does not equal causation, which is what we learn in studying the scientific method.

  8. I forgot to add; I grew up in lead painted homes; pumped lead based gasoline for several years as a teen-aged pump jockey; painted houses with lead paint; washed my paint brushes in — you guessed it — lead based gasoline with my bear hands; for most of my youth, drank water out of lead pipe systems. Have yet to commit an act of gun violence. There's a correlation of heavy use of lead with lack of violence — but I can't prove there is a causation.

  9. It's hard to believe there is still that much lead out there to be exposed to. I would say it's a hard core matter of race, IQ, and culture. I've been watching the real crime shows and it's always some low IQ duh-versities that live in the ghetto doing drugs or selling drug or someone 'dissed dem' and they had to shoot back. Sure, there are problem whites that need removal from society, but they cause far less problems. But we can't talk about that cuz that would 'da rasis'.

  10. Blacks are most of the shooters and most of the victims.
    The fact that blacks live in poor neighborhoods with corrupt politics is related. Poor + corrupt leads to still existing lead pipes. (Lead paint only hurts you if you're already dumb enough to eat it.)

    You know, it's funny. When whites lived in those neighborhoods (decades ago, when they were new), they didn't go around killing each other nearly as much.

    So, what we seem to have here is that being black leads to: poverty, violence, criminality and corruption. I'd simplify that to a more basic root cause of being dumb leads to poverty, violence, criminality and corruption.

  11. What to do? Shoot jacketed bullets when possible, and all .22 shorts, longs, and LRs should be shot downwind. Couldn't hurt.

  12. proven in england when lead levels from smoke went down crime reduced also the people who were born in the lead times were actually uglier than their descendants who were lead free

  13. deb harvey and Quartz. The correlation is more like the correlation that Fluoride stops tooth decay. People assume it does, because a study was done. What people don't know is that the control groups (municipalities) went ahead and started fluoridating the water before the study was done, thus invalidating the whole study. What the study actually proved was the non-control groups had better tooth care before and during the study than the control groups, which saw no difference in tooth decay before, during and after the study. But everyone knows flouride is good to stop tooth decay, right?

    The industrial levels of lead involved in the English studies were far above the level of contaminates found in most houses with lead paint and lead pipes and leaded gas. Like industrial levels of lead. Not standard levels of lead.

    Else most range employees, auto-tire workers, miniature figure game players, home shooters, home smelters, home reloaders all would show far more ugliness and tendency to violence than 'normals.' Which we just don't see.

    Industrial (very high) levels of contamination from anything is hazardous to one's health. Moderate levels of lead exposure, as found in most homes, aren't, for the most part.

  14. @Divemedic – Central and South America, Africa, and rather large portions of Asia haven't really experienced a drop in violent crime. It just doesn't get reported.

  15. Whenever you see a correlation of this magnitude, According to their findings, 56% of the shooters and 51% of the victims were found to have blood lead levels equal to or greater than the recommended limit of lead exposure of 5 micrograms per deciliter. it's not worth further investigation or action.

    There's simply too many other explanations. Perhaps both lead exposure and violence are caused by something else and the test has found the link to the mysterious "something else." All a study like this can ever do is justify further study.

    As others have said, correlation is not causation. The only exception is something called the Bradford-Hill criteria, which basically say that if the effect is "ginormous" like it was with smoking (smokers got lung cancer something like 15 times more frequently than non-smokers), and if there's a plausible mechanism, and if a few other criteria are met, then you can attribute causality.

Leave a comment

Your email address will not be published. Required fields are marked *