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Lead exposure in last century shrunk IQ scores of half of Americans: study

today.duke.edu

341–350 of 508 posts

Re: Lead exposure in last century shrunk IQ scores of half of Americans: study

#341

I really doubt that. While I am aware of shrinking IQ, as far as I know its a thing of the last 30 years, leaded gas in most developed countries was already outlawed.

IQ reduction is totally expected from the moment contraceptive methods became fully available. Common sense seems to be out of fashion these days, but Idiocracy was spot on: the dumber you are the more prone to "unexpected" pregnancies you'll be. The future will not be Star Trek.

Re: Lead exposure in last century shrunk IQ scores of half of Americans: study

#342

I was recently horrified to learn that the baby glass bottle I had been using with my baby had lead paint on it. https://tamararubin.com/2021/12/sailor-themed-glass-nuk-baby... Apparently, it's considered to be acceptable by current standards. Despite the fact that babies will obviously touch the bottle (and the paint) and then put their hands in their mouth. I bought glass bottles because I wanted to avoid plastic t…

learned about teflon via the movie 'Dark Waters'... it was horrifying

Re: Lead exposure in last century shrunk IQ scores of half of Americans: study

#343

Earlier quoted context omitted.

It was banned in the US in 1978.

So this is all historical and not being removed because of the cost?

Correct. Though note also that lead paint was being phased out already earlier than 1978, so single-family homes built after 1960 or so are less likely to have lead. That still leaves a lot of dwelling units, particularly those that were not renovated recently (i.e. cheaper places).

Re: Lead exposure in last century shrunk IQ scores of half of Americans: study

#344
post #69

Earlier quoted context omitted.

But then there's been a huge rise in crime. The murder rate in some cities is dramatically higher than just a few years ago. But it's not like the gas suddenly became leaded again. This makes me think that we just can't be too certain about these things.

There was not huge rise in crime in general. There were more murders during lockdowns in US, which is in fact to be expected since people were forced to be with close relatives - and most murders are by close people.

Murders have been on the rise since 2014 or so

Re: Lead exposure in last century shrunk IQ scores of half of Americans: study

#345
post #298

Black children had an adjusted 0.73 to 1.41 µg/dL more blood Pb (p https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7084658/

Is it certain that the Pb causes the lower IQ or maybe there is some other factor and poorer people happen to have higher concentration?

It one of the most impactful studies on how lead affects intellectual development, the researcher (who is white) restricted the study to white people only because he assumed (correctly) his results would be ignored if he included African Americans who are disproportionately affected by lead poisoning.

Re: Lead exposure in last century shrunk IQ scores of half of Americans: study

#346

I was recently horrified to learn that the baby glass bottle I had been using with my baby had lead paint on it. https://tamararubin.com/2021/12/sailor-themed-glass-nuk-baby... Apparently, it's considered to be acceptable by current standards. Despite the fact that babies will obviously touch the bottle (and the paint) and then put their hands in their mouth. I bought glass bottles because I wanted to avoid plastic t…

There's also https://en.wikipedia.org/wiki/Titanium_dioxide#Possible_carc..., which is used in many glazes and coatings, but also as a whitener in health supplements and toothpaste!

Re: Lead exposure in last century shrunk IQ scores of half of Americans: study

#347
Has widespread use of lead been exclusive to the US ? I'd imagine that there are other countries which still haven't transitioned off lead, and that they can be used as control. Alternately, are there states that never embraced widespread lead use and if they can be used as a control too ?

Some also attribute the removal of lead to substantial decrease in violence over the last few decades. So, I am not surprised that the effect size here is so large.

Might an impolite question to ask, but is there a known correlation between IQ and propensity for physical violence ? (controlled for socio economics and protected classes of course)

Re: Lead exposure in last century shrunk IQ scores of half of Americans: study

#348

Earlier quoted context omitted.

You can’t ban everything… Marijuanna and sugar and a million other potential vices like alcohol and video games should be available. But we should teach kids discipline, critical thinking, and impulse control - rather than playing whack-a-mole with every vice that comes along.

as we're a society increasingly made up of single parents with a poverty of energy and time. not to mention their own education on these matters.

Perhaps we should solve that problem then.

Re: Lead exposure in last century shrunk IQ scores of half of Americans: study

#349
post #345
post #298

Earlier quoted context omitted.

Is it certain that the Pb causes the lower IQ or maybe there is some other factor and poorer people happen to have higher concentration?

It one of the most impactful studies on how lead affects intellectual development, the researcher (who is white) restricted the study to white people only because he assumed (correctly) his results would be ignored if he included African Americans who are disproportionately affected by lead poisoning.

How can you assume correctly if you aren't even testing that assumption?

Re: Lead exposure in last century shrunk IQ scores of half of Americans: study

#350
post #347

Has widespread use of lead been exclusive to the US ? I'd imagine that there are other countries which still haven't transitioned off lead, and that they can be used as control. Alternately, are there states that never embraced widespread lead use and if they can be used as a control too ? Some also attribute the removal of lead to substantial decrease in violence over the last few decades. So, I am not surprised tha…

> Has widespread use of lead been exclusive to the US ?

No. Leaded gasoline was used throughout the world. Leaded paint on the other hand was in some cases banned in other countries 50 years before it was in the US.

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