Lead in gasoline blunted IQ of half the U.S. population, study says
nbcnews.com
nbcnews.com
Humanity is full of mistakes like DDT and lead makeup. We continue to make these mistakes today, but it’s important to know that we progress with technology.
CFCs are no longer necessary and high octane unleaded now can be had at the pump.
Yes, it allowed a lot of progress. But society should have been able to make an informed decision about whether it was worth it.
Sounds like most disruptors, PI-based, and food companies today - Facebook algorithms, Uber's early safety/compliance/sexism issues, etc. I wouldn't be surprised if certain food related things become a big deal in a couple of decades. Stuff like hormones and meds in animals and xenohormones in packaging. Even things like synthetic food dyes have some evidence of hyper activity in children, to the point the EU is putting warning labels on some things.
When the CEOs have their families avoiding their own products, that's a damn big warning that they know. It shouldn't be a surprise.
It should matter who gets rich. People have for too long been naively (or foolishly) swallowing the elite-favored narrative that someone else's money is none of anyone's business; a dynamically imbalanced moral which may have been weakly defensible in a byegone world that was far less tightly integrated, consolidating and wealth-connected than it has become.
What is the total damage to the economy of making such a colossal number of people less smart, for the entire duration of their life?
The cost must be colossal, in trillions. Imagine if 1% drop in IQ costs us 1% loss of GDP, in that case m, over the past decades, we have suffered more damage that the entire GDP of USA. Someone should be paying that!
And someone in this thread has rightly pointed out, will microplastics be the same?
P. 78
We do. Your observation likely reflects a data source selection error on your part.
21% of adults in the US are illiterate in 2022.
54% of adults have a literacy below sixth-grade level.
21% of Americans 18 and older are illiterate in 2022.
https://www.crossrivertherapy.com/research/literacy-statisti...
You say it’s a “cost” but equal education obviously isn’t a priority in our country and I can’t help but wonder who benefits from such a high percentage of illiteracy (this is semi-rhetorical).
I genuinely don’t think we’re tracking the cost appropriately nor implementing solutions with enough urgency; 10-15 years down the road this empire of ours is going to be far out-classed intellectually by countries that actually implement policy for the equitable benefit of everyone.
If I’m off base I’d appreciate an education on this topic as it’s quite gross to think about our elite institutions being proponents of eugenics in the past[1] and how that likely spilled over into the world-building we did after WWII (Kissinger etc).
Or put another way, how do we map “AI is going to save everyone” rhetoric to how history has actually gone, and what incentive do existing power structures have to change?
Two years after he got lead poisoning, he did a demonstration where he huffed TEL and poured it on his hands and claimed he could do it every day without consequence. Nobody believed him, perhaps because it was no secret that lead exposure was dangerous. The state of New Jersey didn't believe it either and shut down his plant, and he later came down with lead poisoning again and had to take a leave of absence.
So to your point, these were the actions of a man who saw people in his factories dying, came down with lead poisoning twice himself, and kept selling the stuff. That's not a lack of foresight, that's just greed. He just didn't care. The benefits he saw were "making a shitload of money".
I can't imagine he knew about the dangers in that case. Even someone amazingly greedy would be unlikely to risk the very serious complications doing this would cause.
If you yourself have to take a leave of absence (admitting the cause) and dozens of your employees become sick with the same thing (many of whom die), it's certainly not unknown. Whether it's unappreciated or ignored is different. In this case I don't think we can know for sure.
I would speculate, though, that Midgley knew exactly what he was doing. After the state of NJ shut down his plant, the feds had it reopened. TEL was important for military purposes. Midgley knew that he found himself possessing a key ingredient for internal combustion. It's not often that you can insert yourself as a key component of an existing (fifteen year old!) industry. He knew he could put on a show and downplay the risks, and if he pulled it off he'd be rich like a Rockefeller.
reminds me of the guy who made millions (billions?) selling identity theft protection theatre (LifeLock IIRC) by running an absurd ad campaign in which he put his own name and SSN in public advertisements for the service, and promptly had his identity stolen, and kept having stolen over and over for years.
But with hundreds of millions in the bank selling this scam he likely had plenty of other resources to mitigate the damage, resources his millions of customers likely do not.
Morale: Don't follow the man with the seriously damaged IQ.
Lead toxicity wasn't some big unforeseeable surprise, there was over two millennia of documentation on the dangers of lead when Midgley kicked off the mass production of tetraethyl lead.
It's better to just say the man was cursed. He also brought Freon to market. Arguably no living person has done as much environmental damage as he accomplished single-handedly. As Bill Bryson said, he had "an instinct for the regrettable that was almost uncanny."
[1] https://www.whitehouse.gov/briefing-room/statements-releases...
https://www.epa.gov/sdwa/use-lead-free-pipes-fittings-fixtur...
The article that the OP was written about is case in point. One calculation they do in their paper is the sum of all IQ points lost due to Pb exposure, which comes out to some absurdly large number. Sums of IQ points don't mean anything. It's just a sensational marketing gimmick. And it worked! It got them a national mainstream news article. Reporting their findings on lead exposure without the sensational IQ point calculations and commentary probably would not have gotten them a national news article.
Made me think of this:
1. Make up some scientific "evidence" that exposure to some common, harmless substance is actually harmful.
2. People believe it. Smart people make an effort to avoid it. Dumb people don't care.
3. Measure it 30 years later, and now there's a correlation between higher IQ and lower exposure to the substance. Higher IQ causes lower exposure to the substance.
I'm not saying this is the case with Pb, it's just a funny idea.
Smart people make an effort to avoid it, dumb people don't care.
Is your sense that the number of smart people leaving the US each year is greater than the number of smart people moving to the US each year?
> I'm not saying this is the case with Pb, it's just a funny idea.
My view is that poverty, low IQ, and lead exposure are all caused by intractably complex webs of genes, behaviors, beliefs, and parenting styles. This occurs in such a way that high IQ, high socioeconomic status, and low lead exposure are all strongly correlated, but not perfectly correlated.
As a spherical-cow sort of model, imagine that there's a "I don't give a fuck" (IDGAF) gene. People with the IDGAF gene have higher levels of lead exposure (because their houses aren't as clean), lower IQs (because they're not as motivated to think hard about the IQ test problems), and lower socioeconomic status (because they're not as motivated to get high-paying jobs) relative to those without the gene. But some IDGAF-positive people will get lucky and end up with high-paying jobs. Some IDGAF-negative people will be impoverished due to bad luck, etc. In other words, socioeconomic status is a noisy indicator of IDGAF. The key point is that IDGAF-positive people who have good jobs still probably don't keep their houses as clean as IDGAF-negative people. So when you control for poverty, you've killed off most of the IDGAF-mediated correlation between lead and IQ, but not all of it.
(as a reminder, this was just a spherical-cow model for illustrative purposes... reality is intractably more complex!)
Back when lead levels were mostly in the 10-20 mcg/dL range, the observed correlations with IQ were typically around 3-5 IQ points per standard deviation of lead exposure. Now that lead levels are an order of magnitude or two lower, the observed correlation is still... 3-5 IQ points per standard deviation of exposure. Blood levels of other environmental toxins have also been correlated with IQ. These studies typically come in around... wait for it... 3-5 IQ points per standard deviation of exposure.
The common-sense explanation, in my opinion, is that developmentally delayed children eat more dust and dirt.
Do you have thoughts on why such a strong correlation would appear other than some causal influence?
To be sure, there could be other factors at play. But nobody, I mean nobody, is suggesting that lead is safe. We know it messes you up. There is evidence that it really messes you up.
My belief is that lead is a noisy metric for dirt/dust ingestion, which correlates with IQ for a variety of reasons. Homes of poor families tend to be dirtier, and wealthier families tend to live in newer suburban housing farther from curbs for example, but that sort of thing is pretty easy to control for. The big thing that can't be controlled in a straightforward way, is developmentally delayed children eating more dust/dirt. To a much lesser extent, this also correlates negatively with IQ in adults due to pica, disregard for cleanliness, etc correlating negatively with IQ. But the lead-IQ correlation is strongest at age 2, and that's no coincidence.
Observable symptoms of lead poisoning occur at blood levels above ~60 mcg/dL, which is 3-4 times higher than the levels studied in 1970s-era lead IQ research, and about 2 orders of magnitude higher than the levels studied in contemporary lead-IQ research. The latter body of research reports significantly larger effect sizes than the former.
https://en.wikipedia.org/wiki/Lead–crime_hypothesis#Correlat...
https://www.themarshallproject.org/2023/11/03/violent-crime-...
Whichever way that data is cut, though, pre-2000 and in particular mid 70s "peak lead" crime levels are far and away worse than those of the past two decades.
Edit: why disagree? I can claim that the size of the standard Hersey bar had a positive correlation over that time too. That doesn't mean there's a convincing causative mechanism. Most of the studies linking lead to crime rely on poor data practices, such as testing blood levels of convicted criminals. There are very easy explainations to show bias here, such as smarter criminals being less likely to be convinced and criminals with higher blood levels tending to have lower IQs. Many exclude certain areas like DC or NYC in their analysis or the trend disappeared. Many used state level data points which are not granular enough to investigate causative effect (eg median income at the state level is not useful. You need to investigate it at the individual level. Things like localized cost of living and standard of living would also be more useful numbers). The designs and data are sloppy as hell in my opinion.
It's just that meta-analysis over many studies seems to show that it is a contributor to crime. When it is removed from the environment, it then shows up in the crime data.
many studies seems to show that it is a contributor to crime."
This seems contradictory. How can it not cause violent crime yet be a causative factor?
I can see how it might be correlated. But I've never heard a compelling argument for how it would be causative.on any significant level.
Edit: It's worth noting that the study described by the OP does not demonstrate an effect on IQ. They estimate population-wide lead exposure. The lost IQ point calculation is based on correlation coefficients obtained through observational studies.
Observational research is how we know that smoking cigarettes causes health issues. We don't have 30 year RCTs on smokers. And there is no such thing as causation vs correlation. All we have are causal inferences draws from correlation.
Finally, when you suggest there are confounders, that's a causal claim. What confounders do you have in mind here, what standard of evidence do you need to accept them as confounders, and do they supersede the evidence we have for lead and IQ?
A lot of it depends on how well the controls were done and what follow-up research was done. Thongs like identifying and confirming mechanisms of action are a huge difference between some basic correlation and claimed causation. In the case of exposures, you can work backwards - reduce blood levels and perform tests to see if functions return. That's a lot easier than identifying people before they meet the criteria. Although that's still possible, especially when dealing with certain vocational scenarios where tests can be performed before possible exposures.
You'd need a large study to determine if stopping smoking reduces future risk of tumors; it's not something you can determine in a single person.
And they have done some studies that seem to prove the risk does decrease after cessation and continues to decrease over time.
> Finally, when you suggest there are confounders, that's a causal claim. What confounders do you have in mind here, what standard of evidence do you need to accept them as confounders, and do they supersede the evidence we have for lead and IQ?
Dirt and dust ingestion, for which lead is a noisy metric. It's no accident that the correlation between lead and IQ is strongest at age 2. That's the age by which the smarter children have figured out that dust bunnies don't taste very good.
1) Multiple researchers have obtained U-shaped lead-IQ curves which regress toward the mean at extreme values. This, in my opinion, strongly implies that the lead-IQ correlation only occurs in the "ordinary exposure through dirt and dust" regime.
2) The effect sizes reported back in the 70s, when lead levels were an order of magnitude or two higher than they are now, were significantly lower than the effect sizes reported in contemporary research. In both cases, however, they can be broadly summarized as "3-5 IQ points per standard deviation of exposure".
From [1]:
> ... younger adults to be the only age group with an increase in overall cancer incidence between 1995 and 2020—the rate has risen by 1% to 2% each year during that time period. ...
> Colorectal cancer, while still overwhelmingly a disease that affects older people, is now the leading cause of cancer death in men younger than 50 and second in women in that age group. The numbers have been rising steadily in people 55 and younger since the mid-1990s, according to the ACS.
1. https://www.yalemedicine.org/news/cancer-in-younger-people-o....
My suggestion would have been social media.
But the moment that you bring up how there might be a environmental/biological component to the extremely rapid increase in LGBT identification, particularly in the youth, they think you're Alex Jones. Sorry, no. I'm simply someone who internalized the message that movies like "Children of Men" were sending.
People think you're Alex Jones because it's a very, very dumb reach.
Punk wasn't something in the blood.
Recent LGBT craziness is just a trend like any other.
The problem is that this isn't true once you factor out disease status (such as obesity, which is rising).
If you can’t question things for fear of being labeled a conspiracy theorist is a signal to question those things.
The best mass produced oils are probably olive and avocado.
This video has a pretty good breakdown of the science: https://youtu.be/IDZmXzAMmwI
It would be something that experts know about and warn against.
That certain cities and countries have already banned based on expert input.
It would be something manufacturers know about and hide info on and actively lie about.
It would be something that even after regulatory laggards like the US federal government ban it, is still inflicted on the globally poor and powerless.
The recent thing about a pesticide affecting unborn children fits neatly for example.
Tetraethyl lead is an anti-knock compound, and turbines don't knock. It's good that it's being phased out, but saying "aviation uses leaded gas" leads people to think that commercial aviation uses leaded gas, which hasn't been the case for longer than most of us have been alive.
Turboprops are only 8% of planes flown commercially[0] and the category is dominated by small planes, avgas consumption vs. jetfuel is on the order of 2-4%, as a napkin estimate.
[0]: https://www.statista.com/statistics/573231/aviation-industry...
As others state, tying lower IQ to TEL is sketchy at best.
I'm guessing it's posted now as a response to the Kansas Attorney General's recent Twitter post that questions the benefit of removing lead pipes:
"Biden wants to replace lead pipes ... all for benefits that may be entirely speculative."
https://twitter.com/badmedicaltakes/status/17662226122485760...
Anyway what is the DOI of that research (or anyone got the direct link?). I like to read through than being summarize by nbc.
More for people born earlier decades like 1960s and 1970s
I wouldn't be surprised it we find out that microplastics or a different substance continued the trend for 1990s and 2000s babies
It might be this one: https://pubmed.ncbi.nlm.nih.gov/35254913/
Half of US population exposed to adverse lead levels in early childhood
https://www.pnas.org/doi/10.1073/pnas.2118631119
Choice Quote:
Significance
We estimate population-level effects on IQ loss and find that lead is responsible for the loss of 824,097,690 IQ points as of 2015.
Cognitive impairment is a terrifying idea but I think it’s important to balance the risk of COVID-associated cognitive impairment with the risk of cognitive decline that would result from whatever social isolation would be necessary to avoid COVID.
Is cognitive decline due to COVID really comparable to that of lead exposure? If so, I’d really appreciate more concrete information to put the risk into context.
Distributions are often more interesting than averages or medians alone.
Reporting a loss of theoretical IQ points is weird terminology since IQ people want you to believe it's measuring something that exists called "g", but then they don't report this result as a loss of "g". Of course they also happily claim every other test that produces a number like the SAT is also a true measurement of your intelligence and you're doomed to never be able to increase it. Basically they just believe any statement as long as it's got numbers in it and it says something they like.
Is anyone pursuing that
It's interesting how none of the comments here have brought up the "but IQ doesn't mean anything" talking point yet. I wonder why.
Potentially you could interpret this as suggesting a tacit (mathematical) increase elsewhere, but I don't think the math works out like that.
There is in fact an upward trend to IQ scores:
When IQ tests are revised, they are again standardized using a new sample of test-takers, usually born more recently than the first; the average result is set to 100. When the new test subjects take the older tests, in almost every case their average scores are significantly above 100.
Aviation gasoline does use lead-- it's used there to prevent predetonation (engine knock), which is bad for a car engine but really bad in something that's supposed to be keeping you in the air. Replacing it is an ongoing effort, but it's taking a while-- largely because of certification requirements, because it's pretty important to make sure that your new gasoline formulation isn't going to, again, make that thing that's keeping you in the air fail. And there are a lot of older GA airplanes out there that would need recertification for a new fuel.
see "The Secret History of Lead" https://www.thenation.com/article/archive/secret-history-lea...