Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

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

today.duke.edu

Post reply on HN
Print view View original

361–370 of 508 posts

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

#361

Post by LordDragonfang »

dionidium wrote: post #294
veltas wrote: post #6

Didn't we have a previous study debunking this research on statistical grounds?

What has never made sense to me is that the IQ effects aren't equally visible across income/class groups, but we know there are millions of wealthy people living in old housing in Boston and NYC and Providence and so on. Lead levels in those houses must be just as high, right? But those kids aren't experiencing the same IQ effects. Surely this suggests that something else is a bigger factor?

Wealthy people are more likely to have good childcare (nannies, after school activities) where kids spend less time unsupervised and able to, for example, eat paint chips. For that matter, stuff like chipped paint is less likely to be left in a deteriorating state by more affluent owners.

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

#362

Post by S201 »

istjohn wrote: post #331
jccooper wrote: post #258

For context, leaded gasoline phase-out began in 1973, based on the 1970 Clean Air Act. It was largely gone in the US by the 80s but not officially eliminated (except for General Aviation) until 1996. Other countries continued to use leaded gasoline, largely in Africa and the Middle East; the UN started an effort in 2002 to eliminate it in those places still using it. In July 2021, the last stocks of leaded gasoline (…

And we still use leaded fuel in aviation. [1] 1. https://www.faa.gov/about/initiatives/avgas

GA pilot here. This is true and most of us don't like using leaded gas either. It's nasty stuff that leads to increased wear on our engines, is more expensive, and is increasingly used as justification for closing airports. Plus we're exposed to it when fueling our planes.

However, it's worth mentioning that recently the first unleaded avgas, G100UL, was approved by the FAA. We're trying to move away from 100LL (leaded avgas) and are finally making some progress on that front.

https://gami.com/g100ul/g100ul.php

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

#364

Post by [deleted] »

istjohn wrote: post #331
jccooper wrote: post #258

For context, leaded gasoline phase-out began in 1973, based on the 1970 Clean Air Act. It was largely gone in the US by the 80s but not officially eliminated (except for General Aviation) until 1996. Other countries continued to use leaded gasoline, largely in Africa and the Middle East; the UN started an effort in 2002 to eliminate it in those places still using it. In July 2021, the last stocks of leaded gasoline (…

And we still use leaded fuel in aviation. [1] 1. https://www.faa.gov/about/initiatives/avgas

[deleted]

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

#365

Post by downrightmike »

Small airports have more smaller prop planes, fun fact, they almost exclusively use leaded gas because it gives them more power. So if you live near one, you're getting a dusting of lead everyday. Like this one in the middle of $500k+ homes suburbs: https://www.google.com/maps/place/Chandler+Municipal+Airport...

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

#366

Post by maerF0x0 »

kikokikokiko wrote: post #341
jhoechtl wrote: post #325

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.

you never know. We might be able to hit a critical mass with Authoritarian regimes regulating reproduction, and through gene editing.

Perhaps when we finally translate "unintelligent people" into "vermin" we'll do what many previous iterations of society have done... genocide.

Part of this is literally possible. A big part of made stark to point out that we should be careful in the way our language dehumanizes people of below average intelligence. They're still part of our species, and biological history.

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

#367

Post by trophycase »

pessimizer wrote: post #318
zelon88 wrote: post #215

Earlier quoted context omitted.

I wasn't there in the 70s, but from what I understand potency of the 70s wasn't nearly what it is today. I have no source for this, but I've been in countless circles with long time smokers who all correlate the same story; that modern day mids was literally the best quality Marijuana you could find in the 70s. So that's probably about 10% THC compared to 30% THC which is not uncommon today.

When you smoke with people these days, they only take a couple of hits. In the 90s when we smoked it was joint after joint after joint. It's basically the cigarette filter thing; people know where they want to get, and they'll keep going until they get there, no matter how weak you make it. Which is what made filtered cigarettes worse for your lungs than unfiltered ones. The calculus would be different if you were ta…

I wish we could go back to that. Personally I find most weed I smoke these days to be way way too strong.

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

#368

Post by mark-r »

hadlock wrote: post #289
jccooper wrote: post #258

For context, leaded gasoline phase-out began in 1973, based on the 1970 Clean Air Act. It was largely gone in the US by the 80s but not officially eliminated (except for General Aviation) until 1996. Other countries continued to use leaded gasoline, largely in Africa and the Middle East; the UN started an effort in 2002 to eliminate it in those places still using it. In July 2021, the last stocks of leaded gasoline (…

Yeah in the US I recall in 1991 or 92 the pumps had "UNLEADED" in great big letters running up the side of them. My dad's '77 chevy had a gas gauge near the center console that said "UNLEADED FUEL ONLY". There's been another push to get rid of leaded gas in aviation but studies show that it's virtually undetectable in the environment.

They made the gas tank filler hole a smaller diameter for unleaded gas cars, so that the leaded nozzles wouldn't fit.

https://uiobservatory.com/2010/how-intelligent-design-saved-....

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

#369

Post by dmitrygr »

downrightmike wrote: post #365

Small airports have more smaller prop planes, fun fact, they almost exclusively use leaded gas because it gives them more power. So if you live near one, you're getting a dusting of lead everyday. Like this one in the middle of $500k+ homes suburbs: https://www.google.com/maps/place/Chandler+Municipal+Airport...

This has been disproven so many times, it is tiring to even try. Small amount, dispersed over huge distances. Current measurements indicate NO more lead in the blood of people near airports than not. It is only heard nowadays from land developers seeking to capitalize on a few acres among "the middle of $500k+ homes"

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

#370

Post by 09bjb »

hadlock wrote: post #289
jccooper wrote: post #258

For context, leaded gasoline phase-out began in 1973, based on the 1970 Clean Air Act. It was largely gone in the US by the 80s but not officially eliminated (except for General Aviation) until 1996. Other countries continued to use leaded gasoline, largely in Africa and the Middle East; the UN started an effort in 2002 to eliminate it in those places still using it. In July 2021, the last stocks of leaded gasoline (…

Yeah in the US I recall in 1991 or 92 the pumps had "UNLEADED" in great big letters running up the side of them. My dad's '77 chevy had a gas gauge near the center console that said "UNLEADED FUEL ONLY". There's been another push to get rid of leaded gas in aviation but studies show that it's virtually undetectable in the environment.

Source? I have no reason to doubt you but would love to see where those data. Most of what I heard is that "lead exposure above zero is significant" and "if you're living near an airport, especially one serving smaller plans, you are being exposed".
Post reply on HN