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Comment by papercrane | Hacker News Reader

The lead pipes theory is mostly just pop-science. Romans were likely getting more lead exposure from using lead cooking vessels and utensils.

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Not to mention the fact that their pipes immediately become mineralized, and very little lead leeches in cold water.

Headline science has a way of sticking around for a long time.

Also...Roman plumbing was constant-flow. Lead in water is mostly an issue when it gets to rest in the pipes for a while, then when somebody turns the tap on they get water that's had time to absorb the lead. Since Roman plumbing had no taps though and was just running constantly, the amount of time the water was exposed to the lead was pretty minimal.

spelling pedant: "leaches," not "leeches"

It’s lychees

Plus literally “flavoring” their wine on purpose with lead acetate.

And that was the first and last time that no-calorie sweeteners had deleterious population-level effects

High calorie sweeteners have deleterious population-level effects.

Is there any evidence that modern low calorie sweeteners have deleterious population-level effects, and what are they compared to high calorie sweeteners?

Anecdotally I get gut dybiosis (microbiome imbalance) that notably only occurs when using artificial sweeteners and stops when I stop taking it, I’ve talked to many others who have noticed the same thing. Gut dysbiosis can cause chronic systemic inflammation which is rather bad for the body, not sure if it’s worse than the sugar it replaces, but it shouldn’t be assumed that the problem is solved by low calories. I think it’s important to limit both, preferably to near zero.

Sugar alcohols are especially bad for this. I fried my GI one year and it was largely down to developing a gum chewing habit at a time when sugar alcohols were in almost all gum brands. You can’t process them, but bad gut bacteria can.

It sucks so much, because xylitol appears to be very good for your teeth but bad for your heart:

https://www.nih.gov/news-events/nih-research-matters/xylitol...

I wonder if any Romans evidence had any evidence of population-level delirium from lead consumption...

Lower intelligence would likely surface as hedonistic behavior which is probably hard to distinguish from decadence. Decadence and hedonism were constantly being complained about long before the eventual fall.

> Lower intelligence would likely surface as hedonistic behavior why do you think so

poor decision making

Violence in the US declined as children born around and after leaded gas was banned reached the average age of first offense. It’s quite a line.

You're going to have to explain your point to me, or perhaps you misunderstood my own.

My point is that while it may have been unclear to the Romans as to the cause of changes in behavior they did notice a change and did complain about it a lot. I accept the premise that lead poisoning leads to lower intelligence.

What we know now is that lead’s effects are more pronounced as developmental issues. A little lead exposure as a child can lead to a violent temper. So once children were not born into a low grade cloud of lead contamination, they were set up for fewer mood disturbances as teenagers and young adults. Feeling like violence is your best avenue for conflict resolution leads to crime. So the change wasn’t over night, it was over 20 years.

I expect that whatever effect was going on in Rome if there was one, which seems to be up for debate, counted on pregnant women exposed to lead via alcohol and acidic foods, neither of which young children would normally encounter. Meanwhile lead dust from exhaust got -everywhere-, and paint a lot of places.

I still think you are agreeing with the implied and later stated accepted premise that there is a correlation and it’s not always obvious, I’m still unsure as to what it is you are trying to add.

> Violence in the US declined as children born around and after leaded gas was banned reached the average age of first offense

My pet hypothesis for the generation born after in the mid postwar era having been a general scourge on America is that we had a population boom amidst lead.

Hard to square the fall with lead poisoning when the leadership after the 3rd century hardly even bothered to go to Rome at all.

It's too easy to point at the Claudians as the beginning of the fall. In a way, the "Real" Roman empire began to fail once Augustus took over.

Joseph R. McConnell et al. (January 6, 2025). Pan-European atmospheric lead pollution, enhanced blood lead levels, and cognitive decline from Roman-era mining and smelting. https://www.pnas.org/doi/full/10.1073/pnas.2419630121

So is the idea that widespread lead exposure led to the decline of the Roman empire largely pop science? Are you saying that's not accurate, or that the source of the lead exposure is miscounted?

Yes, that is the modern understanding. Widespread lead exposure had very little / nothing to do with the decline the Roman Empire.

Plus to prove the lead connection you have to discount the centuries of Roman dominance and growth during which lead exposure was common.

This is a much better point. It's not like there were more lead pipes during the decline than the rise.

Wouldn't there necessarily be more lead pipes at the peak and post-peak? Assuming that pipe-building was some non-linear function of dominance, which seems a fair assumption, we would start with 0% pipes at 0% rome and asymptotically close to 100% pipes at the asymptotic 100% peak rome. Is this a bad assumption, or is it basically just pedantry?

It would be more about lead pipes per capita, possibly as rome itself grew wealthier from conquests they added more and more piping, but it would be hard to relate this to any specific moment in time.

Presumably the wealthy elites had their pipes installed first anyways.

"Decadence" likely had nothing to do with the Roman Empire's fall. That theory is based essentially on propaganda, designed to absolve them of blame.

The lead pipes had too much calcification, and not much lead would have leached out. But the Romans did use lead acetate as a sweetener, so they were adding lead directly to many (most?) of their meals.

there are many ways to account for the fall of the roman empire, and everyone chooses their favorite (usually depending on where their interest bends). for example, it could be explained by the increased usage of mercenaries in the roman army. i like this theory because the fall was brought by losses to renegade forces. it could also be explained by bad leadership.

also lead flavoring

lead tastes sweet, sugar wasn't cheaply & widely available, honey is expensive etc.

and knowledge about lead poisoning was not really a think AFIK

at the same time lead pipes tend to gain a crust of chalk over time (depending on chalk content of the water) which mostly defuses their danger. Like you will find some very old houses with lead tape water pipes in the EU today but if you test their tape water you won't find (much of) an issue due to 1) the chalk 2) the water not staying long in the pipe if it's e.g. a 4 apartment house.

Here's Vitruvius in "De Architectura" claiming it's common, easily verified knowledge: https://penelope.uchicago.edu/Thayer/E/Roman/Texts/Vitruvius...

Of course, him mentioning "Don't do this" suggests that lead water pipes into the home were common enough to need a warning against.

interesting

> "Don't do this" suggests that lead water pipes into the home were common enough to need a warning against.

sadly, they still are today sometimes, in areas with a lot of 125+year old infrastructure :/

Interestingly, in 2017, a research found that crime rates in US dropped as lead pipes are replaced with better alternatives [0].

[0]: https://www.brookings.edu/articles/new-evidence-that-lead-ex...

Which continued pretty much into the modern age. Nothing specifically Roman about it.

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