Mastodawn

David Meyer 5d ago

Comparing historical hair samples from people from when they were babies to today, a new study finds a nearly 100-fold decrease in lead from samples after the EPA's crackdown on leaded gas. Regulation works and it saves lives!
https://arstechnica.com/science/2026/02/a-century-of-hair-samples-proves-leaded-gas-ban-worked/

Dr. Dan Killam Feb 3

The study from Cerling et al. I saw Thure Cerling talk about his work when I was a grad student, fascinating stuff! https://www.pnas.org/doi/10.1073/pnas.2525498123

Martin Vermeer FCD Feb 3

@dantheclamman Nothing about environmental lead and crime, which appears to be a thing...

obscurestar Feb 3

@martinvermeer @dantheclamman Truthfully, this would be very hard data to draw any conclusions from. There are just too many other factors. For instance, the shift from mostly human manufacturing to mostly robotic manufacturing (which began happening at increasing scale post WWII) the stagnation of wages are going to drive crime. Also the CIA selling arms to Iran to buy drugs from Noriega to dump on US streets to increase crime as a way to attack minorities. Too many factors. Hard to isolate.

@obscurestar @martinvermeer @dantheclamman Actually, the lead-crime correlation shows up across all industrialized societies in 20c. That the curves line up despite different countries industrializing and moving to automobiles at different times indicates that lead exposure was a major factor. It was not contained in the US, far from it.

I think the burden of proof is on those who suggest that what we know to be true about lead exposure for individuals and small groups of people somehow doesn't scale to large groups.

obscurestar Feb 3

@tasket @martinvermeer @dantheclamman I don't at all doubt that lead, particularly tetraethyl lead isn't toxic and a contaminant on a massive scale (not to mention used for the stupidest pure greed reasons). Even the Romans knew that lead was bad news. Correlation across many industrialized nations can well constitute a smoking gun but correlation is not always causation. Just urging caution with blanket statements.

Dr. Dan Killam Feb 4

@obscurestar @tasket @martinvermeer Yes, caution is merited. A recent meta-analysis showed there probably is an association between lead exposure and crime, but the relationship is not cut-and-dry. It explains some of the variance, but there are other contingent factors or "confounders" at play, with kids exposed to high lead and also having greater socioeconomic need showing the biggest negative effect. The review authors point out many studies do not account for that and some other interactive effects. https://pmc.ncbi.nlm.nih.gov/articles/PMC10393136/#sec011

The association between lead exposure and crime: A systematic review

Prior research has demonstrated an association between lead exposure and criminal behavior at the population-level, however studies exploring the effect of lead exposure on criminal behavior at the individual-level have not been reviewed ...

PubMed Central (PMC)

Peter Ralph Feb 3

@dantheclamman wow, and the decline is continuing exponentially through today, looks like

Martin Vermeer FCD Feb 3

@petrelharp @dantheclamman Yep, like radioactive decay

@dantheclamman @petrelharp Yeah, but if you're not used to lin-log plots, it makes you think the decline is slower than it really is. Always a problem with public communication.

poppypunkpilgrim Feb 3

@dantheclamman great news aside, am i the only one that finds this graph very beautiful as well? i love aesthetically pleasing depictions of data

Orrock LXXXVI XLVII Feb 3

@dantheclamman similarly strontium 90 in baby teeth

JSMuellerRoemer Feb 3

@dantheclamman Isn’t it great being an (early) Millenial? Almost the same lead dose at birth, but no chance of owning a home. But yes, regulation works, another example is CFCs/HCFCs and the ozone layer

@JSMuellerRoemer @dantheclamman "Elder Millenial" Is the term you are searching for. 😆 🖖

JSMuellerRoemer Feb 3

@JDGeoShack @dantheclamman I know the term, I just don’t like it 😆

@JSMuellerRoemer @dantheclamman LMAO - embrace it with me! With age comes wisdom.

JSMuellerRoemer Feb 3

@dantheclamman @JDGeoShack dunno, I feel with age comes anger and rage against capitalism and conservative politicians (i.e. all that aren’t on the very left end of the spectrum these days, which is basically the 90s center left). But maybe that’s not about age, more about a system hellbent on ending humanity? 🤔

@JSMuellerRoemer @dantheclamman AKA Wisdom 😆 You're spittin' facts right now. Keep on, you lovely fediverse citizen you. ❤️

@JDGeoShack @JSMuellerRoemer @dantheclamman i’m definitely older than elder millennials and have doubts about a strong positive correlation between age and wisdom.

@dr_a @JSMuellerRoemer @dantheclamman It's not always true for sure...and those who claim to be wise may simply be prideful! It's complicated... 🖖

JSMuellerRoemer Feb 13

@JDGeoShack @dr_a @dantheclamman I generally go by the rule of never trusting anyone who calls themselves wise or an expert – or wears a suit

@JSMuellerRoemer @JDGeoShack @dantheclamman that’s an interesting rule, although in a previous life not a particularly good one for me.

JSMuellerRoemer Feb 15

@dr_a because you were (required to be) a suit wearer yourself or because your superiors were suit wearers? Or more related to self-proclaimed wisdom/expertise?

@JSMuellerRoemer in one part of my past it was the environment i worked in. in another part, there was the pleasure of clothing that fits extremely well. for better or worse, suits are one of the few items of clothing that it’s easy to get tailored on a budget.

with regard to experts, a lot of my old professional life involved people who were acknowledged as experts and denying one’s own (externally acknowledged) expertise was considered dishonest.

today suits are for fun.

Sassinake!Feb 3

and that's why they are going to roll them back.

Dr. Dan Killam Feb 3

@Sassinake the paper actually explicitly calls this out in a way I rarely see in a discussion section. very powerful and kind of chilling

The damage done by this is staggering. It will continue to affect humans for several generations. Leaded paint will also be an issue for decades to come.
edited because I was born in the high lead era

Good to see this evidence!

Flaming Cheeto Feb 3

@dantheclamman Kevin Drum would've loved this

No soy Mario Feb 3

@dantheclamman but won't anybody think of the shareholders and how these evil regulations make them miss out on the last pennies for their return on investment! /s

RealGene ☣️Feb 3

@dantheclamman
I know I'm a broken record (or looping GIF) on this, but a large reason Pb levels aren't even lower is Avgas, the 100-octane gasoline fuel burned in virtually all reciprocating-engine aircraft, which still contains tetraethyl lead.

https://en.wikipedia.org/wiki/Avgas

Avgas - Wikipedia

obscurestar Feb 3

@dantheclamman But without lead causing irrational impulsive behavior and brain damage, how will the GOP get new voters?

raspberryswirl Feb 3

@dantheclamman recommending this lead story, facinating
https://www.youtube.com/watch?v=IV3dnLzthDA

The Man Who Accidentally Killed The Most People In History

YouTube

@raspberryswirl @dantheclamman
Veritasium always does good stuff.

leftofcentre Feb 3

@dantheclamman that pussy grabbin pig pedonald seems to have the a brain eaten by this affliction..

The Polish Dispatch Feb 3

@dantheclamman How many of those leaded babies are members of congress today?

This Old Hiker Feb 4

@ThePolishDispatch @dantheclamman People aren't talking about it, but the people in charge of businesses and governments around the world are exactly the age group who received the maximum doses of environmental lead. I strongly suspect that this fact is behind our worldwide political instability. I'm in this age range and I think that we need to take away grandpa's car keys.

Khleedril 5d ago

@Patrickoldhiker @ThePolishDispatch @dantheclamman Also... Covid.

This Old Hiker 5d ago

@khleedril @ThePolishDispatch @dantheclamman COVID too, and it is definitely being seen in population behavior in the US.

Dr. Dan Killam 5d ago

@Patrickoldhiker @khleedril @ThePolishDispatch I worry a lot about collective impacts of cognitive decline and general mental health. It seems like there isn't much data to help us quantify whether our population-scale baseline has shifted, and that's scary to me.

Lead was also found in pipes, gasoline, paints, etc. And amalgam is still used today. When it comes out, it is hazardous waste.

A big shoutout to BP's Kwinana refinery which, with the complicity of WA's corporate captured government kept producing leaded petrol way past 1996.

The government's own article below celebrates this remarkable achievement.

#WesternAustralia #Perth #ColinBarnett #Kwinana #BP

https://www.wa.gov.au/government/media-statements/Court%20Coalition%20Government/Opening-of-BP-Kwinana-refinery-project-resulting-in-lower-lead-levels-in-petrol-19960202

Opening of BP Kwinana refinery project resulting in lower lead levels in petrol | Western Australian Government

2/2/96Lead levels in petrol have again been reduced significantly as a result of new high-tech upgrades at BP Kwinana's oil refinery.

Western Australian Government

MidgePhoto Feb 4

@dantheclamman your Senators and President formed their brains before 1980.
This may show.

Kevin Russell Feb 4

That's a 20% increase in population IQ

Michael Gemar Feb 4

@kevinrns @dantheclamman Perhaps one factor in the Flynn Effect?

https://en.wikipedia.org/wiki/Flynn_effect

Flynn effect - Wikipedia

Kevin Russell Feb 5

@michaelgemar @dantheclamman

Lead poisoning causes almost 10% of intellectual disability of otherwise unknown cause and can result in behavioral problems.[2]

Tito Swineflu Feb 5

@dantheclamman This is me! I took my kid in to get tested for lead, and he was fine. The threshold for lead is something like 0.5 parts per million. The Dr, who is my age, turned to me and said, "you and I would have been 20 ppm as kids."
Imagine how much smarter we all could have been.

Dr. Dan Killam Feb 5

@tito_swineflu yes, it makes me sad to think off all the potential lost, but happy to know society made the right choice

I am Jack's Found 404 6d ago

I was wondering about this the other day... Is leaded gas still allowed/used anywhere else in the world?

Dr. Dan Killam 5d ago

@float13 small aircraft still use it, and some racing cars. Those are the biggest remaining users of leaded gas

Eugene Parnell 5d ago

@dantheclamman Have you read the book "Murderland" by Caroline Fraser? It's about the link between air pollution (lead, arsenic, sulphur dioxide) and the serial killer epidemic in the Pacific Northwest in the 50s -80s. It's not a scientific book, but the correlation is pretty eye opening.
https://bookshop.org/p/books/murderland-crime-and-bloodlust-in-the-time-of-serial-killers-caroline-fraser/156e2df8d7c9c05c