The Lancet Commission on Pollution and Health, and IQ

The Lancet Commission on Pollution and Health, an authoritative review with well-over a dozen distinguished co-authors, is unusually forthright on the effect of pollution, most especially lead, on IQ. I think some of their numbers, especially in paragraph three, are too large but the direction is certainly correct.

Neurotoxic pollutants can reduce productivity by impairing children’s cognitive development. It is well documented that exposures to lead and other metals (eg, mercury and arsenic) reduce cognitive function, as measured by loss of IQ.168

Loss of cognitive function directly affects success at school and labour force participation and indirectly affects lifetime earnings. In the USA, millions of children were exposed to excessive concentrations of lead as the result of the widespread use of leaded gasoline from the 1920s until about 1980. At peak use in the 1970s, annual consumption of tetraethyl lead in gasoline was nearly 100 000 tonnes.

It has been estimated that the resulting epidemic of subclinical lead poisoning could have reduced the number of children with truly superior intelligence (IQ scores higher than 130 points) by more than 50% and, concurrently, caused a more than 50% increase in the number of children with IQ scores less than 70 (figure 14).265 Children with reduced cognitive function due to lead did poorly in school, required special education and other remedial programmes, and could not contribute fully to society when they became adults.

Grosse and colleagues 46 found that each IQ point lost to neurotoxic pollution results in a decrease in mean lifetime earnings of 1·76%. Salkever and colleagues 266 who extended this analysis to include the effects of IQ on schooling, found that a decrease in IQ of one percentage point lowers mean lifetime earnings by 2·38%. Studies from the 2000s using data from the USA 267,268 support earlier findings but suggest a detrimental effect on earnings of 1·1% per IQ point.269 The link between lead exposure and reduced IQ 46, 168 suggests that, in the USA, a 1 μg/dL increase in blood lead concentration decreases mean lifetime earnings by about 0·5%. A 2015 study in Chile 270 that followed up children who were exposed to lead at contaminated sites suggests much greater effects. A 2016 analysis by Muennig 271 argues that the economic losses that result from early-life exposure to lead include not only the costs resulting from cognitive impairment but also costs that result from the subsequent increased use of the social welfare services by these lead-exposed children, and their increased likelihood of incarceration.


So we believe IQ is an effective metric in this context, but not in selecting job applicants or prospective students?

IQ is also valid metric when Our Presidential Candidate has a higher IQ than Yours.

Though as far as I know the last presidential election where both IQs were public knowledge was JFK vs RMN where, amazingly, the much higher IQ of Nixon was little mentioned.

"We" just don't like it when "IQ" is used as a proxy for "race," often by the same people who fight "environmental regulations."

Is the person with an IQ of 120 the same as the person who should have had an IQ of 130 but lost 10 points due to neurotoxicity? I dont know but it seems probable they are different. There is a lot of decent evidence linking high lead levels to crime. So in this case we might just be seeing IQ decrease due to neurotoxic pollution acting as a proxy for everything else.


The study is sloppy and worse biased. They had their agenda and searched for anything that might support it.

Most epidemiology is pretty worthless stuff. I'm hoping someone might come along and explain why this is an exception.

Jobs require a diversity of skills and character traits, and IQ test tells you nothing about most of them.

But we generally have even weaker and more ambiguous ability to assess character, and many skills, than IQ. That’s not a reason to not use IQ.

What's preventing us from devising better methods of assessing character and many skills?

"What's preventing us from devising better methods of assessing character and many skills?"

Our low IQs.

Well played!!

How about Johnson v. Trump?

What? I thought it was a terrible, horrible, no good, very bad thing to believe that there is such a thing as IQ. And even worse to think that it is important.

Wouldn't it be sad if regions with less environmental concern spiraled down, unaware that they were doing it to themselves..

Would be interesting to compare former East and West Germany, given the rather notorious pollution history in the Warsaw Pact countries.

This is almost entirely about lead paint in homes, with children eating lead paint chips. (Leaded gasoline was phased out in 95.)

In a better world Congress would be debating how to remove lead paint from old houses. This isn’t a partisan issue, since neither side’s enemies rises or falls in status.

Since there’s no culture war aspect, I doubt any state under unified party government will be rolling out any large scale lead removal programs.

How many old homes with paint-eating children are we talking about? Everybody had lead paint and leaded gasoline for decades but we still seem to have accomplished a lot. Is this an argument that we would have invented wireless communications even sooner?

Lead paint hasn't been available on the open market for over 40 years (1978) at this point. The EPA has routinely tested and determined the percentage of the US toddlers (age 1 to 5) with more than 10 µg/dL of lead in their blood.

1980 - 88.2%
1991 - 8.9%
1994 - 4.4%

Over 20 years ago that number dropped to 0%. The current detectable level is a mean of 0.758 µg/dL for children ages 1 to 5. Which is essentially the same as the adult population.

Children eating lead paint is a statistically rare event at this point.

Yes. We also would have been smart enough to buy Amigas over Macs and the invasion of the IBM clones never would have happened in a lead- free America.

Betamax would have won over VHS.

just because it worked 'well enough' in the past doesn't mean it was ok. Suppose we had been losing two IQ points on average due to lead use. How would we have known? Yet the losses would be very large and tragic.

Keeping heavy metals out of the brains of young people seems like the lowest hanging fruit there is.

I'm all in favor of low-hanging fruit, like the Kiwanis International's Worldwide Service Project to eliminate cretinism by iodide supplements or a single sewage treatment plant in Haiti. But I'm skeptical of the thesis that Jonas Salk MD would have invented the cure for cancer in addition to the polio vaccine but for leaded gasoline and paint.

The outcome wouldn’t be cure for cancer.

It would be less violent crime, fewer teenage pregnancies, less social dysfunction. Which tracks with the data, although I’d say it’s one of many factors not the only one.

I owned rental property in Maryland that was over a century old in a historical zone that limited major changes to the property. There were thick layers of lead paint. Before each new tenant we had certified third parties do visual and dust wipe tests and scrape and repaints. The properties had an annual walk-through inspection, where visual flaking was looked for.

I don't think Maryland is special here.

A place with serious paint flakes would need to be owned buy a rogue landlord okay with huge legal risks. More importantly, the mother, or parents, would have to be extremely neglectful, and frankly, low IQ, not to notice problems. You can skip the landlord and call the city and get action. Low IQ is heritable, and parents like this are not going to be producing National Merit Scholars, lead chips or not.

I wonder what Ashkenazi Jews have been doing that the rest of us haven't? Do they scrupulously police their environs for lead, arsenic and mercury? It's all terribly complex, a riddle wrapped in a mystery inside an enigma.

My brother pointed out to me recently that when many Jews in Germany converted to Christianity that it was likely the less well off part of the Jewish population that disproportionately did so. That is, the most intelligent and wealthiest Jews could afford to retain their Jewish heritage, while the poorer and less intelligent were more likely to convert so as to avoid being stigmatized. If only the elite Jews were left, that would have skewed the innate intelligence of the remaining Ashkenazi population upwards.

The Jews all got killed in Germany, even the conversos. And the IQ premium for Ashkenazi Jews is still there for Jews not of German descent, which is most of them.

Most in the US are from Eastern Europe, and their ancestors got out of Europe before Hitler (obviously)

Large scale conversions to Christianity among Jews occurred both in Germany and Eastern Europe over several centuries, up through the late 19th century. I'm not talking about the Nazis.

I read a book about 19th century German Jews. I think it was called "The Pity of It All." Anyway, that isn't how it worked, is my vague recollection. Your grandfather Moses Mendelssohn entered Berlin through the gate marked for cattle and Jews - and became very successful. You, his musical grandson (I believe), converted like many others because it was necessary to reach the top of one's field, or even just to earn the academic post for which you had studied; this may have been true of the military as well, also the law, I think. But my impression is you chose conversion when you had attained a certain level of success that made being "fully German" seem within your grasp.

Like Heine, who knew he could make Germany love him as it had Goethe: but not, perhaps, as a Jew.

And even the very wealthiest Jews were never really free. Among many financial favors they performed for the government, they were forced, for example (I recall from an anecdote in the book) to purchase ugly surplus product runs from the royal pottery. Memorably including some porcelain monkeys which were especially hideous, apparently, and are now perhaps collector's items because of this fraught history.

Sorry, trying and failing to reply to Hazel.

I have a suspicion that in each generation a few percent of young Jewish men converted to Christianity because they couldn't intellectually hack the high expectations.

And similarly at the other end, the most able are the most likely to leave various Traveller etc. communities. A good term for this is "evaporative cooling".

Shouldn't IQs and school quality be going up if lead has been dropping for 30 years?

On the other hand, violent crime rates have been falling, and part of that may be related to lower heavy metals in brains.

Lead in the environment dropped precipitously in the 1980's. The effects would have all occurred well before now. Of course Kevin Drum does think that it explains the fall in violent crime.

Actually, IQ scores were going *up* over the period when lead was most in use. This was called the Flynn effect, and no one has ever explained it. Moreover, scores in many countries then started going *down* over the last 30 years. So basically the Lancet's conclusions run counter to what empirical evidence we have as to IQ.

I thought these IQ environment effects

Were measuring the effects

Of household air quality and IQ


Pot smoking and second hand pot smoke.

"reduce productivity "... "loss of IQ"... "increased use of the social welfare services "... "increased likelihood of incarceration"...

This certainly explains Hong Kong. Or not.

related: Lucifer Curves: The Legacy of Lead Poisoning-- Rick Nevin

I have failed to notice the higher intelligence.

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