
New Evidence That Lead Exposure Increases Crime (2017) - anarazel
https://www.brookings.edu/blog/up-front/2017/06/01/new-evidence-that-lead-exposure-increases-crime/
======
dalore
> When lead was removed from gasoline, lead levels in the environment fell,
> and kids avoided the lead exposure that caused these developmental problems.
> About 20 years later, when those kids became young adults, crime rates fell.
> This, proponents say, is what explains the mysterious and persistent decline
> in crime beginning in the early 1990s.

> It’s an intriguing idea — particularly since we don’t have a better
> explanation for the big changes in crime rates during this period.

Did not freakanomics come up with a famous (and to me more convincing)
argument that it legalized abortion was the reason for the drop in crime? At
they very least it dispels the arguments we don't have a better explanation
and doesn't even mention it.

[http://freakonomics.com/2005/05/15/abortion-and-crime-who-
sh...](http://freakonomics.com/2005/05/15/abortion-and-crime-who-should-you-
believe/)

~~~
lordnacho
One of the interesting things about social science observations is there's a
lot of noise.

Both the lead and the abortion hypotheses could be true. In fact they could
both be true AND the papers indicating one explanation could conceivably throw
out the other explanation. If you're interested in one hypothesis, you might
not spend the time going through alternatives as thoroughly as someone
investigating the other.

Looking specifically, the studies are always trying to isolate some effect,
often using some sort of clever control derived from the proposed mechanism.
So in this case there's a paper that points out how lead only goes into the
water if the water is acidic, and they look at places with non-acidic water or
non-lead pipes to control. For abortion, it's been a while since I read it,
but there would be something along the lines of when abortion became
widespread in a given community. You'd then look at differences in frequency
and think about whether that came out in the crime stats when the kids got
older.

The rabbit hole is where you can come up with ever more interesting
corollaries and data that support or do not support some hypothesis. You see
this across the social sciences all the time. There's also confounding
problems, say you know people tend to move to the city when they grow up (I
don't know if this is true), then how valid is your birth -> crime data?

Here's a load of random observations I thought up:

\- If abortion is the key, why do crime rates keep falling? Why is it not a
step effect?

\- If it's lead, did crime rates increase 20 years after leaded fuel became a
thing?

\- What if it's abortion AND lead? There are countries where abortion and lead
are timed differently, how about looking at them?

\- What if it's neither, but both are caused by some other thing? Say economic
development -> both?

~~~
sutterbomb
>> If it's lead, did crime rates increase 20 years after leaded fuel became a
thing?

Yes. The rise and fall of violent crime rates correlate very tightly to the
rise and fall of leaded fuel, with a ~20 year gap. You see the same
correlations in different countries that had different phase in / phase out
times, and different U.S. states that had different timelines. (E.g. if a
state phased out leaded gas 5 years earlier than average, their crime wave
also started abating 5 years earlier than average)

~~~
refurb
Source? Crime in general decreased quite a lot after the depression, but the
use of leaded gasoline was quite prevalent regardless.

~~~
AnthonyMouse
Leaded gasoline was introduced in the 1920s but there weren't that many _cars_
until starting in the late 1950s. (Construction of the interstates started
with the Federal Aid Highway Act of 1956.) Then we saw the huge crime wave
starting 20 years later, which peaked and started tapering off in 1993, 20
years after the phase out of leaded gasoline began in 1973.

There is also the point that the people who did have cars in the 1920s were
the aristocrats, and twenty years after that...

~~~
UncleEntity
> Then we saw the huge crime wave starting 20 years later, which peaked and
> started tapering off in 1993...

This seems to correlate fairly well with the government's war on (certain)
drugs as well.

~~~
anoncoward111
It also correlates with population density, public housing, migration, and
crack cocaine use.

I highly doubt there's one contributing factor to crime, and I highly doubt it
is solely from leaded gasoline.

~~~
smallnamespace
There are many things that influence crime, the question is how much of the
total variance is due to gasoline?

And the answer from this research is _quite a lot_ , because the _timing_ of
the rise and fall in crime match the timing of leaded gasoline (with a 20-year
lag) across cities, states, and countries.

To say that 'other factors are responsible' would be to posit that there is
some other factor that holds both across and within different cultures and
countries that perfect accounts for the pattern in crime rates that we see.
That seems much harder to believe than simply 'leaded gasoline causes crime',
which we both have robust evidence for now, and for which we have a very
plausible mechanism of action.

~~~
anoncoward111
Ok, so I'm not disputing that peope born in the 60s had more lead in their
blood than people born in the 80s/90s. Additonally, I'm not disputing that
lead causes behavioral and physical problems. It definitely does.

However, I would like to see the specific data that says the following
(because I'm not seeing it when I read the article):

"Regardless of the crack epidemic in the 1980s, regardless of the decline in
public housing in the 1980s, regardless of the rise of police surveillance
technology, we have indisputable evidence that lead in the blood causes an
increase in crime locally and nationwide by XMeaningfulPercent".

I'd be surprised if one could ever make such a statement.

The data we currently have shows that someone born in 1960 and committing a
crime in 1985 has been exposed to lead, but they also might have been exposed
to crack. Additionally, declining government project housing provided strong
protection for criminals to hide from police, and the police surveillance
technology in 1985 was pitiful compared to the massive levels of surveillance
now.

None of these factors exist anymore in 2018. Crime is much lower. How can we
say which variable contributed in which amount?

~~~
sutterbomb
Your standards are bullshit and you know it. We can't say such statements of
indisputable evidence about anything that happens in the world. Should we
throw our hands up and just say, well it could be invisible llamas, or tree
gnomes, or the boogey man, or should we use the best available evidence to
guide future decisions?

From one of the papers cited in the parent article:

"A growing body of evidence in the social and medical sciences traces high
crime rates to high rates of lead exposure. Scholars have shown that lead
exposure and crime are positively correlated using data on individuals,
cities, counties, states, and nations. Reyes (2007) exploits state-specific
reductions in lead exposure due to the Clean Air Act to estimate the effect of
lead emissions from gasoline on violent crime. She reports that reductions in
childhood lead exposure in the 1970s and 1980s accounted for more than half of
the violent crime decline of the 1990s.2 Stretesky and Lynch (2001) estimate
that, from 1989 to 1991, counties with air lead levels equivalent to .17 μg/m3
had homicide rates four times as high as counties with air lead levels
equivalent to 0 μg/m3. Mielke and Zahran (2012) show that air lead and
aggravated assault rates were strongly associated in a panel of U.S. cities.
Longitudinal studies of individuals document a positive relationship between
pre- and post-natal lead exposure and delinquency (Dietrich et al., 2001) and
arrests for violent offenses (Wright et al., 2008). Cross-sectional research
on individuals (Denno, 1990; Needleman et al., 1996, 2002) and counties
(Stretesky and Lynch, 2004), studies using cross-national panel data (Nevin,
2007), and analyses of national time-series (Nevin, 2000) have yielded similar
results."

Are each of these going to be able to factor for every possible confounder you
can think of? No. But it's not like they aren't controlling for anything.
That's the whole gist of the parent article - three studies using three new
ways of controlling for other variables. Have you seen multitudes of studies
that point to any of those other confounder you mention having better
evidence, across time and geography, while controlling for lead and all the
other possible confounders? Again, nobody is arguing that there are no other
factors. And nobody has a precise answer on just how much, because it's
impossible. But all studies point to: very large effects, still happening in
some cases, and largely preventable:
[https://www.dropbox.com/s/07z65p9a5wdppfl/LifeAfterLead_AEJ_...](https://www.dropbox.com/s/07z65p9a5wdppfl/LifeAfterLead_AEJ_Revision_3_16_17_wRevNotes.pdf?dl=0)

~~~
dang
> _Your standards are bullshit and you know it._

Aggressiveness like this will get you banned on HN. Please read
[https://news.ycombinator.com/newsguidelines.html](https://news.ycombinator.com/newsguidelines.html)
and follow the rules when posting here.

~~~
sutterbomb
I mean I'd say that in civil conversation, face to face. Is swearing the
problem? I was providing substantive contributions to the conversation,
whereas conversant was, in my opinion, doing neither of these:

> Please respond to the strongest plausible interpretation of what someone
> says, not a weaker one that's easier to criticize. Assume good faith.

> Please don't post shallow dismissals

But perhaps doing neither of them more "civilly"? I'm genuinely looking for
guidance on handling of this thread, not trying to argue. Thanks.

------
GreeniFi
Half of Mexican children suffer from lead poisoning.

[http://latinalista.com/columns/globalviews/nearly-half-
mexic...](http://latinalista.com/columns/globalviews/nearly-half-mexicos-
children-suffer-lead-poisoning)

~~~
galaxyLogic
And we know there is a lot of violent crime in Mexico

~~~
ekianjo
Violent crime is Mexico is rather a consequence of cartel activity. Which has
nothing to do with lead.

~~~
nyolfen
why is it so easy for you to rule that out? there are cartels in other
countries, but mexico's are exceptionally, brutally violent

~~~
shawn
Suppose lead were to disappear from the earth tomorrow. It seems unlikely that
it would have any effect on the Mexican cartel ecosystem.

The ecosystem is driven by demand from the US, and Mexico has the supply. The
brutality is a consequence of a power struggle to control those resources.

~~~
smallnamespace
> It seems unlikely that it would have any effect on the Mexican cartel
> ecosystem.

How can you on the one hand so easily dismiss the evidence that lead causes
violence, which is backed up by rigorous statistical analysis and medical
evidence, and on the other hand assert so surely that you know the answer?

If you were consistent, surely you'd apply skepticism to your own explanations
as well.

~~~
shawn
The fact that lead causes violence isn't in question.

Violence is caused by multiple factors. One additional factor is the billions
of dollars to be made preparing and running drugs from Mexico to the US.

My assertion is that if lead were removed as a factor, this would not negate
the other cause.

~~~
int_19h
But is all that violence actually _necessary_ for cartels to profit? Some of
it probably is, but all? There are many organized crime syndicates around the
world, and they usually are involved in drug trade - but rarely you do see
such open and extreme violence as in Mexico, including mass targeting of
civilians (which is usually considered bad for business everywhere).

------
Sileni
One of the most dangerous forms of lead is Tetraethyllead, because of how fat
soluble it is. It's been banned in nearly every country in the world because
it moves through the environment at an alarming rate. One company in the world
still manufactures it, and they're based in the UK[0].

They're entirely aware that they're killing people and have openly said in
management meetings that they won't stop manufacturing the product until
government regulation forces them to.

Mind you, lead levels don't only increase in the country the chemical is used;
it moves through entire ecosystems and across oceans. Lead levels don't fall
to below dangerous levels for decades. This isn't just poisoning the people
nearby; it's poisoning the entire world in small, insidious ways. And chemical
companies are profiting from that. The margin they're selling TEL for would
make government contractors cry.

And to top it off, they have virtually no quality program surrounding their
products because they don't need one; all of their deals are done with
backroom handshakes and agreeing to take the blame if an issue arises. Their
company is built around the idea that it actually costs less to just say
"Yeah, we're terrible people, fine us" than to actually try and comply with
government regulation. They've repeatedly been caught in corruption and
environmental probes, and have changed their names in the states and in the UK
multiple times. They were literally caught trying to bribe their way into
selling TEL in Iran. [1]

[0]: [https://www.independent.co.uk/environment/leaded-petrol-
alge...](https://www.independent.co.uk/environment/leaded-petrol-algeria-
still-legal-innospec-cheshire-uk-sale-export-tel-tetraethyl-
lead-a7907196.html)

[1]: [https://www.sfo.gov.uk/2014/08/04/four-sentenced-role-
innosp...](https://www.sfo.gov.uk/2014/08/04/four-sentenced-role-innospec-
corruption/)

[1]: [https://www.sfo.gov.uk/cases/innospec-
ltd/](https://www.sfo.gov.uk/cases/innospec-ltd/)

~~~
refurb
Leaded gasoline is still used in aviation, so in fact it’s not banned in every
country of the world but Algeria?

Article is pretty low quality.

~~~
Terr_
Note that most big passenger jets and such use kerosene, which is unleaded. In
terms of leaded avgas, it's the smaller planes you've got to worry about.

~~~
londons_explore
The small old planes - typically hobbyist classic planes.

------
baxtr
A was very skeptical when I saw the headline. Then I read the article. The
evidence coming from these 3 studies looks quite compelling I have to say.
Next I googled: “Countries That Still Use Leaded Gasoline”, and I got:

Rank ﻿Location 1 Algeria 2 Iraq 3 Yemen 4 Myanmar 5 North Korea 6 Afghanistan

From [https://www.worldatlas.com/articles/countries-that-still-
use...](https://www.worldatlas.com/articles/countries-that-still-use-leaded-
gasoline.html)

Also I found this: [https://www.motherjones.com/kevin-drum/2016/12/prediction-
te...](https://www.motherjones.com/kevin-drum/2016/12/prediction-terrorism-
middle-east-will-decline-half-between-2020-and-2040/)

Very interesting indeed.

~~~
phakding
> Rank ﻿Location 1 Algeria 2 Iraq 3 Yemen 4 Myanmar 5 North Korea 6
> Afghanistan

I am hoping you are not attributing violence and instability in some of these
countries to lead based gasoline. Sure, there may be correlation, but these
places are centuries old. There are many factors like culture, religiosity,
socio-economic status , history, contemporary culture, so on and so forth.

~~~
astrodust
Since their use of fossil fuels is significantly lower than European countries
it's not a direct comparison, but an interesting situation.

Lead affects impulse control and could be a factor in certain civil phenomena.
It's easier to whip up a mob when there's a lot of lead poisoning.

~~~
fjsolwmv
That's a stretch. It's just as easy to say that national instability leads to
both civil war and lack of modern technology like unleqded gasoline.

~~~
smallnamespace
Yeah, which is why the data is backed up by multiple panel analyses that
actually make the argument for causation. The US data shows that crime rates
rose like clockwork approximately ~20 years after leaded gasoline is used en
masse, and drops ~20 years after it was banned.

Different states introduced and subsequently banned leaded gasoline on
different schedules, so this was a 'natural' experiment, unless you can think
of some other causative factor that precisely explains the timing of the rise
and fall of crime.

I don't understand this content-free 'correlation does not equal causation'
argument.

Sure, in the _absence of other evidence and a mechanism of action_ , we should
have healthy skepticism, but it's known how lead affects brain development,
particularly how it screws up development of the frontal cortex, lowering both
intelligence and social inhibition.

~~~
refurb
_Yeah, which is why the data is backed up by multiple panel analyses that
actually make the argument for causation. The US data shows that crime rates
rose like clockwork approximately ~20 years after leaded gasoline is used en
masse, and drops ~20 years after it was banned._

Did they also account for changes in how crime rates are reported over time?

One would have to account for hundreds of different variables before you could
ever conclusively prove a connection between lead and crime.

~~~
sutterbomb
It would be impossible to 100% conclusively and with absolute precision
determine the exact connection between the two. That doesn't mean it's not the
best available theory at the moment, that fits the most data. There are
international, interstate, and even local level analysis all pointing to the
same thing. There are longitudinal studies on children pointing to the same
thing. And there are established and direct casual mechanisms in the brain
biology that explain it. So what does waving a hand and saying "Nah nah can't
prove it" do? By your standards do we have zero knowledge on all sociological
matters, since it's impossible to design and implement a perfectly controlled
study?

------
makosdv
Makes sense.

"Lead exposure in childhood linked to lower IQ, lower status jobs, as adults"
[https://www.sciencedaily.com/releases/2017/03/170328145300.h...](https://www.sciencedaily.com/releases/2017/03/170328145300.htm)
Which also correlates with criminality.

------
mirimir
I was going to ask why the cited studies apparently didn't consider the
phaseout of lead-based paint. But then I realized that the first study relies
on data preceding the lead-paint problem, in that lead paint wasn't used as
much indoors then, and arguably wasn't in bad shape. The third study just
considers lead levels and interventions, and so subjects were exposed to
multiple sources.

The second study[0] finds that distance to roads correlates with lead
exposure. They do discuss relative contribution from multiple sources: flaking
indoor lead-based paint, lead in soil around foundations (from maintenance of
outdoor lead-based paint), and roadside lead.

0) [https://sci-hub.tw/https://www.nber.org/papers/w23392](https://sci-
hub.tw/https://www.nber.org/papers/w23392)

------
kurthr
And of course, it's the gift that keeps on giving!

[https://arstechnica.com/science/2018/08/lead-in-us-school-
wa...](https://arstechnica.com/science/2018/08/lead-in-us-school-water-
disturbing-detroit-just-shut-off-all-fountains/)

------
krrrh
This 2016 Mother Jones article is a good treatment of this hypothesis:

[https://www.motherjones.com/environment/2016/02/lead-
exposur...](https://www.motherjones.com/environment/2016/02/lead-exposure-
gasoline-crime-increase-children-health/)

------
0x17A
"Lead linked to schizophrenia" :
[https://www.nature.com/news/2004/040217/full/news040216-9.ht...](https://www.nature.com/news/2004/040217/full/news040216-9.html)

------
tarsinge
I may have missed something but it looks like Europe is not taken into
consideration in these studies. For example in France lead in gasoline was not
banned until the 90’s, and the violent crime statistics doesn’t look very
correlated.

~~~
scotty79
Crime lags around 20 years behind lead levels.

Young people burning cars in Paris suburbs around 2010 may not be technically
violent crime but it's pretty weird and special. And also in decline:

[https://www.google.pl/amp/s/www.thelocal.fr/20180102/is-
the-...](https://www.google.pl/amp/s/www.thelocal.fr/20180102/is-the-famous-
french-tradition-of-torching-cars-dying-out/amp)

------
losvedir
Does anyone have any resources with concrete numbers about how much lead
exposure is too much? I just moved into a new house that has a lead service
pipe in from the city, and it concerns me. In addition, the federal action
level is 15ppb, and my utility's water report last year had it at 8ppb, which
seems kind of close.

I know there's no known level of safe lead exposure, but I don't have a good
sense from a cost benefit perspective of how much to do to try to lower my
exposure.

~~~
scottlocklin
Water filters are cheap and effective and make the water taste better anyway.
I think most people's exposure is from eating lead paint and breathing fumes
and particulates (also from paint -previously from gasoline engines). None the
less, the US is visibly decaying enough I always drink filtered water (google
"big berkey").

------
freeflight
Without wanting to sound too snarky, wasn't this already pretty well-
established knowledge? [0]

Imho one of the more infamous and recent examples of human hubris. Who knows
what we are downplaying right now, that might end up really messing us up in
another couple of decades? Only time will tell.

[0]
[https://en.wikipedia.org/wiki/Tetraethyllead#Controversy_and...](https://en.wikipedia.org/wiki/Tetraethyllead#Controversy_and_phase-
out)

~~~
sutterbomb
I thought so, and I wish it were. But look at the threads here, and everyone
who feels that they can just say "crack epidemic" and believe it is providing
the same insight into the situation as scientific study.

------
rejectedalot
In Elizabethan England, didn’t a lot of women wear lead based makeup? I’d be
interested in seeing how that affected crime rates or other metrics, if that
data were available.

------
outworlder
Could it be that there are other pollutants that could cause similar issues?

Some countries have banned lead even before the US, but crime rates are still
growing(Brazil, for instance). Poverty alone does not explain this. There are
countries just as poor (or more), with corrupt police forces and that do not
have the same issue with violence.

~~~
corysama
Recent study showing that air pollution can impact intelligence equivalent to
the loss of a year of education.

[https://www.theguardian.com/environment/2018/aug/27/air-
poll...](https://www.theguardian.com/environment/2018/aug/27/air-pollution-
causes-huge-reduction-in-intelligence-study-reveals)

~~~
londons_explore
It's very hard to separate the effects of airborne lead from other air
pollution, since they tend to exist in the same places.

I wouldn't be surprised if the lead is the cause of both.

------
ekianjo
"single variable reductions" used to explain complex societal changes are
hardly convincing.

