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Roman Empire's use of lead lowered IQ levels across Europe, study finds
- leptoniscool 2y agoI wonder if future historians will see a similar drop after widespread use of plastic
- Mistletoe 2y agoHas plastic been linked to lower IQ?
- glitchc 2y agoNot yet, I think the OP means it might in the future.
- userbinator 2y agoIf anything, the correlation might be the opposite --- look at plasticiser use in East Asian countries, for example.
- pseudolus 2y agoPerhaps not with respect to IQ but there’s a chance that future historians might correlate the use of plastics with increased rates of infertility.
- echelon 2y agoPerhaps there is a link between plastics and ADHD [1]. [1] https://pmc.ncbi.nlm.nih.gov/articles/PMC8910189/ https://pmc.ncbi.nlm.nih.gov/articles/PMC8910189/
- TomK32 2y agoI find it interesting that the article you linked didn't mention the heritability of ADHD. In around 3/4ths[0] of cases ADHD is caused by genetics, which leaves plenty of space for other causes. [0] https://www.nature.com/articles/s41380-018-0070-0 https://www.nature.com/articles/s41380-018-0070-0
- User23 2y agoNext do fluoride. That’s been “debunked” though right?
- User23 2y agoFor those that didn’t get the memo: https://www.cnn.com/2025/01/06/health/children-higher-fluoride-levels-lower-iqs-government-study/index.html https://www.cnn.com/2025/01/06/health/children-higher-fluori...
- defrost 2y agoIt doesn't seem as if the principal researcher behind this result is a historian: https://www.dri.edu/directory/joe-mcconnell/ https://www.dri.edu/directory/joe-mcconnell/
- Beijinger 2y agohttps://senecaeffect.substack.com/p/are-plastics-killing-us https://senecaeffect.substack.com/p/are-plastics-killing-us
- TomK32 2y agoOh gosh... "insidious castration of all men" and "blurred gender roles". Really? They have been blurry for all of homo sapiens existence, just think of the matriarchal societies that still exist today[0]. Gender dysphoria has been documented from individuals[1] for a long time, societies accepted a third gender since ancient time and even in the USA, the Cercle Hermaphroditos[2] was quite early to the party, being founded in 1895 (yes 130 years ago). I'm confident that plastic will go the way trees did: Unbothered for a long time until bacteria figured dead wood is just another food and put a stop to trees being fossilized as coal. Stop plastics, it's a good idea to do so for many reasons, but there's no need to drag gender roles and those stupid good old times into it. I much prefer spending time with my kid instead of slaving away 9-5 six days a week. [0] https://www.townandcountrymag.com/society/tradition/g28565280/matriarchal-societies-list/ https://www.townandcountrymag.com/society/tradition/g2856528... [1] https://en.wikipedia.org/wiki/Kalonymus_ben_Kalonymus https://en.wikipedia.org/wiki/Kalonymus_ben_Kalonymus [2] https://en.wikipedia.org/wiki/Cercle_Hermaphroditos https://en.wikipedia.org/wiki/Cercle_Hermaphroditos
- __MatrixMan__ 2y agoMaybe, but given that "plastics" are a broad category I'd expect that IQ would me a poor proxy for some of their effects. BPA for instance, is a xenoestrogen. I'm not sure what metric to watch for it, but it's probably not IQ.
- sebmellen 2y agoAnogenital distance is likely the preferred measure. > Males with a short AGD (lower than the median around 52 mm (2 in)) have seven times the chance of being sub-fertile as those with a longer AGD. > Swan et al. report that the levels of phthalates associated with significant AGD reductions are found in approximately one-quarter of Americans tested by the Centers for Disease Control and Prevention (CDC) for phthalate body burdens. https://en.m.wikipedia.org/wiki/Anogenital_distance https://en.m.wikipedia.org/wiki/Anogenital_distance (warning on the header photos).
- __MatrixMan__ 2y agoI was imagining something a bit more impactful (and easy to find in the data), because as far as that one goes, it's not clear why anyone should know or care. Maybe high school graduation rate (an inverse proxy to indicate bullying)?
- sebmellen 2y agoObviously not as easy to screen for, but this is a very clear indicator of how strong the known adverse effects of plasticizers are.
- curmudgeon22 2y ago> On average, lead levels in children’s blood at the peak of the Roman empire could have risen 2.4 micrograms per decilitre, the researchers found, reducing their IQ by 2.5 to 3 points. When taking background lead into account, childhood blood levels may have reached about 3.5 micrograms per decilitre. > A 2021 study by the Centers for Disease Control and Prevention in the US found blood levels in children aged one to five years fell from 15.2 to 0.83 micrograms per decilitre between the late 1970s and 2016 as leaded fuels were banned.
- luxuryballs 2y ago[flagged]
- CyberDildonics 2y agoLots of people across the world don't have fluoride in their water, you could compare populations right now. https://en.wikipedia.org/wiki/Water_fluoridation_by_country https://en.wikipedia.org/wiki/Water_fluoridation_by_country
- davorak 2y agoI doubt you can do a clean comparison, likely too many confounding factors, at least to pull anything out easily.
- CyberDildonics 2y agoIf someone thinks they can figure out 1500 years from now if the 'fall of the west' was because of fluoride, it's probably easier to look at the countries in the west that do and don't use it now.
- luxuryballs 2y agothat’s the joke, today we are like “huh… lead in water, IQ, fall of Rome!” and that was more than 1500 years ago I think
- friend_Fernando 2y agoI suspect a similarly ugly reality is what happened in Cambodia after Pol Pot's genocide. It's done very poorly compared to its neighbors.
- cmrdporcupine 2y agoSimilarly, arsenical bronze (copper + arsenic) was common before tin started to be used, and I've often wondered how common arsenic poisoning was in the copper age / early bronze age. When we think of the nastiness of industry, it's often industrial 19th century Britain and so on, but some of these villages (often quite remote) back then were full on industrial sites with massive smelting operations and the entire population including children engaged in mining and smithing and then exporting.
- davidgay 2y agoRe arsenic poisoning: https://en.wikipedia.org/wiki/Hephaestus#:~:text=In%20the%20Iliad%2018.371%2C%20it,by%20arsenic%20exposure%20from%20metalworking https://en.wikipedia.org/wiki/Hephaestus#:~:text=In%20the%20....
- agumonkey 2y agoA repair guy taught me recently that up until the 40s cadmium was used as a layer on some metallic devices, then people realized it was toxic. Funny.
- cmrdporcupine 2y agoI mean, I can do better (worse). Up until .. the 60s? 70s? They used to literally spray lead-arsenate on apple orchards as a pesticide. Incredibly effective one, too. Just that unfortunate thing of poisoning the top soil forever. A lot of those old apple orchards have had other things done with them since. Which is kind of scary. https://en.wikipedia.org/wiki/Lead_hydrogen_arsenate https://en.wikipedia.org/wiki/Lead_hydrogen_arsenate "US EPA banned use of lead arsenate on food crops in 1988."
- userbinator 2y agoStill widely used in military/aerospace. https://en.wikipedia.org/wiki/Plating#Cadmium_plating https://en.wikipedia.org/wiki/Plating#Cadmium_plating
- iSnow 2y agoAlso in pigments. There still has to be lots and lots of old devices, paint in houses, glass ware etc. around that derive their color from Cadmium. https://en.wikipedia.org/wiki/Cadmium_pigments https://en.wikipedia.org/wiki/Cadmium_pigments
- aaron695 2y ago[dead]
- PeterHolzwarth 2y agoI have no idea if this is true (and honestly can only barely remember the reference, which I read maybe a decade or two ago), but I believe I saw a comment that the interior of lead pipes eventually develop a "calcified" (don't know what else to call it) lining of the lead reacting to water, such that lead stops leeching into the water that passes through the pipes. I believe this came up when reading something about how the trend of traditional historicity has always been to identify the Big Major Cause of the fall of the Roman empire, but that each explanation ultimately falls short. The followup point made by this, of course, is two-fold: that "falls" are often very complex and multi-faceted; and that the Roman empire never really "fell" in the Gibbons sense - it just slowly evolved, and eventually shifted east, finally becoming self-consciously retro-classically Hellenized, and just morphed to something new and lasted another thousand years -- but never actually fell during that time. Anyone else have any thoughts or insight on the "lead pipes eventually line themselves with something non-lead-like" angle?
- timschmidt 2y agoIt's called mineralization, and happens so long as there are dissolved minerals in the water and PH is correct. Lead contamination happened in Flint, MI because additives to control the water PH were neglected to save cost, and slightly acidic water ate away at the mineralization layer in the pipes and began dissolving the lead again.
- AngryData 2y agoI don't know if I would call Flint's water just "slightly" acidic. It was acidic enough for the Flint hospital to complain about their stainless steel sinks rusting, for local automotive plants to dig their own wells because it was destroying parts they were washing, and turned their entire water supply system into swiss cheese that had to be replaced. It might be slightly acidic compared to highly concentrated acids, but in terms of potable water it seems extremely corrosive.
- timschmidt 2y agoOf course you are right, and no offense meant. I grew up in Flint, and have family there to this day. My intention was more to communicate that even small changes in water PH can affect this mineralization layer. What I rarely see talked about with regard to Flint's water supply is that Detroit was willing to give them water for free, which is documented, and the only explanation that makes sense as to why they weren't taken up on the offer is the state governor's cabinet connections to fracking and a pipeline intended to bring lakewater inland to facilitate fracking. They wanted the taxpayers of Flint to help foot the bill. See: http://banmichiganfracking.org/the-flint-water-connection-to-fracking/ http://banmichiganfracking.org/the-flint-water-connection-to...
- caymanjim 2y agoI find it hard to believe that atmospheric lead levels were higher in the ancient Roman Empire than since the Industrial Revolution. The amount of lead mined and smelted now is vastly more than it was then. Regardless of current safety measures, there were decades with none. And then we had leaded gasoline for a century. Everything in this article may be accurate, but that likely means we're all far worse off now.
- hnburnsy 2y agoWait until you hear about leaded gas!
- khana 2y ago[dead]
- wumeow 2y agoLead contamination is still fairly widespread: carrots, sweet potatoes, chocolate, spices. It’s a good idea to get your blood tested and try to find any sources of exposure if your levels are high.
- jaybrendansmith 2y agoAs a child born in 1970 that loved the smell of gasoline, I really wish I could test how many IQ points I lost. I tell my kids it must be at least 15, because they are much smarter than me!
- peeters 2y ago> Roman Empire’s use of lead lowered IQ levels across Europe, study finds I'm not a fan of this phrasing. None of the findings had anything to do with measuring IQ levels in ancient Europe. They were about measuring historical levels of lead, which they then just plugged into modern models to presume some levels of cognitive effects. A study that was actually able to measure cognitive disparities and correlate them with measured levels of lead would have been extremely interesting, but this is not that. Everything other than the measurements of historical lead levels seems to be fluff. This would kind of be like saying "massive asteroid strike 100m years ago lead to cataclysmic tsunami, study finds" but then not showing any evidence of a tsunami, just evidence that it struck an ocean and the inference that that would have caused a tsunami. It might be a reasonable inference, it's just not as interesting as the title would make it seem. Edit: I should qualify, I'm not trying to say that "they did the math"-style papers don't have value, just that the phrasing in how they are presented matters to me. If the phrasing was more like "Use of lead in Roman Empire would have lowered IQ levels across Europe, study finds" I would have no issue with it.
- PeterHolzwarth 2y agoFully agree, @peeters - as I've mentioned elsewhere in these comments, there's a long-standing trend of trying to identify the one true cause of the fall of the Roman Empire. Each explanation falls short - it's just a complicated thing (and heck, the empire didn't really fall, it just shifted east.)
- hodgesrm 2y agoOr as some wag once put it, the empire then continued to decline and fall for another 1000 years.
- gazchop 2y agoInclined to agree with this. It didn't fall, just sort of withered into other cultural ideologies and empires. Some of it was also fucking bananas which didn't survive enlightenment.
- 2y ago
- Ferret7446 2y agoI can't help but be pedantic and point out that since IQ is normalized, their average IQ would be 100 whether or not they used lead. More philosophically, the condition of life is inherently susceptible to damage, so you practically have to draw the line at what level of damage you want to try and mitigate given the realities of the time. Do you want to be wrapped up, only breathing, eating, and drinking perfectly calibrated mixes of chemicals?
- xeonmc 2y agoWho are you, who are so wise in the Ways of Science?
- anovikov 2y ago…and that brought us Christianity
- gazchop 2y agoAthena was much cooler.
- chrisbrandow 2y agoInterestingly this paper probably underestimates things since it is not evaluating food sources, such as lead sweetened wine commonly drunk by the elites. I suspect the effects were non trivial.
- justlikereddit 2y agoNow do the same study for smartphone abuse and third world immigration
- SMP-UX 2y agoRoman lead pipes were not a significant factor on the health of humans back then... To the same extent as public sewers, bathing, hygiene rules etc. Rome had it a lot better than even some countries today. Yeah you still had to deal with infections and such which could have been deadly but time and medicine era that you were in you had way better health outcomes in Rome
- ashoeafoot 2y agoIts more about lead kettles in which a sweet whine/ sugary additive was boiled down?
- deleted 2y ago[deleted]
- Symbiote 2y agoYou seem to have missed the third paragraph of the article.
- lifeisstillgood 2y ago> A 2021 study by the Centers for Disease Control and Prevention in the US found blood levels in children aged one to five years fell from 15.2 to 0.83 micrograms per decilitre between the late 1970s and 2016 as leaded fuels were banned. So if my generation had lead levels 3-4 X higher than Roman kids, does this explain the “Exams are getting easier” meme - that exams are staying the same, but kids really are getting smarter … ( also the hey exams were waaay harder in the Edwardian Era meme?)
- Anotheroneagain 2y agoExams are getting easier, because children are getting dumber, and wouldn't pass if they stayed the same.
- hunglee2 2y agoHeadline writers were the original click baiters - understandable to get opens but really harms the substance of the article, which is that increase in lead poisoning may have had debilitating impact on the Roman Empire.
- thinkingemote 2y agoOriginal paper https://www.pnas.org/doi/abs/10.1073/pnas.2419630121 https://www.pnas.org/doi/abs/10.1073/pnas.2419630121 ----- Note this isn't mainly about lead pipes: "most significant... may have been through background air pollution from mining and smelting of silver and lead ores "
- baud147258 2y ago> smelting of silver and lead ores The smelting of silver and lead is detectable via ice cores, I remember seeing a graph showing the height of Roman silver production was only matched in the 18th century https://en.wikipedia.org/wiki/Roman_economy#/media/File:World_Lead_Production.jpg https://en.wikipedia.org/wiki/Roman_economy#/media/File:Worl...
- khana 2y ago[dead]
- Anotheroneagain 2y agoRome fell after they stopped using lead. There is no evidence whatsoever that lead was widely known to be toxic, until a group of conspirationists took over the academia. In fact such a belief couldn't have been widespread. The historical quotes appear to be fabricated. In fact it's essential. Roman sewers and sanitation quickly flushed it down the drain, by 235 it was in chaos, long distance trade was no longer possible and a thousand years long dark age ensued. The original depletion happened deep in prehistory, the most major event happening around 26kya. Also by ice cores, substantiated by geological changes and mammoth skeletons.
- panick21_ 2y agoWow, somebody is still repeating 60 historical stuff.
- thrance 2y agoIsn't the average IQ of a population supposed to remain at a 100? Also pretty sure the Romans didn't measure IQ. Anyway, I'm really tired of those "Stupid claim, study finds".
- coderwolf 2y agoIs IQ really that important? I mean, if your goal is to get from point A to point B, having a fast car just means you go there faster. I'm thinking of IQ in a similar way, as in - high IQ = faster car. But at the end of the day, it's still the same, isn't it? Please correct me if I'm wrong.
- whatsupdog 2y agoYes it matters. Faster car can run more miles in a day. More IQ can do more work.
- siva7 2y agoUnfortunately for that we have computers so we don't need high IQ to do more work like calculations but higher quality work (which also depends on what kind of work you're doing) and that is oftentimes not primarily related to high IQ (think of creative work)
- starspangled 2y agoIs that really true? That IQ is often not related to capacity to do valuable intellectual work in the modern world?
- jjk166 2y agoIQ measures reasoning capability, not speed of mental calculations.
- coderwolf 2y agoI think you're right. (Did some ChatGPTing, and found this one holds). But still, I don't believe IQ alone can improve your reasoning capability, could it? Like with proper education, and knowledge, a person with average IQ would more likely be able to see the correct patterns, and connections between ideas, than a high IQ person without the required education would. It's like - having the proper education, trumps the meaning of having a high IQ. But, it's true, given the similar environment, I'd assume, the high IQ person would do better.
- animal531 2y agoIs a 2-3 point IQ drop really that terrible? If we all suddenly went from 100% to 97% brain efficiency we wouldn't even notice. For example a bad night of sleep is surely worth 10 times as much.
- f1shy 2y agoOr even measurable reliably? What is the typical error bar for an IQ test? Also is only kind of estimation based on what is known today about lead...
- imdsm 2y agoI wrote about this last year and everyone here picked on me calling my article AI generated, so I shut down my curiosity blog.
- Pigalowda 2y agoWomp womp
- gradientsrneat 2y agoReading through the submission, it looks like hardly anyone replied or upvoted, the replies seemed like constructive criticism, you acknowledged that you used AI, and you used "we" throughout replies to the feedback. Even in the absence of the article for context, what you are saying now doesn't seem like a fair assessment on behalf of the community, at least from the comment section's side. I will acknowledge there are lowlife trolls who lurk HN, but also flagging an article that is largely created by AI seems reasonable.
- o999 2y ago> By some estimates, the Roman empire amounted to more than 80 million people at its peak, meaning that about a quarter of the world’s population could have been exposed to the lead pollution generated by mining and smelting. The effects of lead poisoning can be so severe that scholars have debated whether it contributed to the fall of the empire. I wonder what will happen to current empires from micro- and nano-plastics, PFAS, airpolution, as well as harmful yet popular habits like doomscrolling and games addictions.
- deadlast2 2y agoWould love to see a similar study on fluoride in modern civilizations.
- nyscof4 2y agoModern day studies show little or no benefit from fluoridation: Cochrane Review https://cochrane.org/news/water-fluoridation-less-effective-now-past?fbclid=IwY2xjawF1LjJleHRuA2FlbQIxMQABHeH4xjAacBa3DFcreQdpVAZPuoPUrN14uUiaf9cnZPzAa44USCADzPL6Vw_aem_1JRRByjhFxhJbGPeGse0bQ https://cochrane.org/news/water-fluoridation-less-effective-... LOTUS Study https://sites.manchester.ac.uk/lotus/#results https://sites.manchester.ac.uk/lotus/#results CATFISH Study https://pubmed.ncbi.nlm.nih.gov/36469652/ https://pubmed.ncbi.nlm.nih.gov/36469652/ When under oath CDC could not provide any evidence that fluoride is safe for the brain https://fluoridealert.org/content/cdc-oral-health-director-we-have-no-safety-data-on-fluoride-and-the-brain/ https://fluoridealert.org/content/cdc-oral-health-director-w... CDC agreed with the 2006 National Research Council findings that fluorides “interfere with the function of the brain and body by direct and indirect means.” CDC KNEW fluoride affected the brain back in 2006, yet did nothing with this information! https://youtu.be/0A34FK2lTDs https://youtu.be/0A34FK2lTDs
- BorgHunter 2y agoFluoride has two major differences that would complicate such a study: First, fluoride is a natural component of lots of drinking water (often at levels far higher than artificial fluoridation creates), while lead contamination in drinking water is rare and usually human-caused. Second, lead is known to be bad for one's health in any amount, while fluoride is only known to cause IQ drops above a certain dose. You might find this meta-analysis interesting: https://jamanetwork.com/journals/jamapediatrics/fullarticle/2828425 https://jamanetwork.com/journals/jamapediatrics/fullarticle/... Part of that conclusion (note that water fluoridation in the US is recommended to a level of 0.7 mg/L): > This systematic review and meta-analysis found inverse associations and a dose-response association between fluoride measurements in urine and drinking water and children’s IQ across the large multicountry epidemiological literature. There were limited data and uncertainty in the dose-response association between fluoride exposure and children’s IQ when fluoride exposure was estimated by drinking water alone at concentrations less than 1.5 mg/L.
- ddgflorida 2y agoSkeptical
- Over2Chars 2y agoHmm, the IQ test was invented hundreds of years after the Fall of Rome. This article correlates 100% with bad causal statements. Garum, anyone?