Lead and the Roman water system - Archaeology of Portus: Exploring the Lost Harbour of Ancient Rome

Half a century after lead poisoning was proposed as the cause of the fall of the Roman Empire, a wave of publications to refute this idea put an end to this theory. Although lead is no longer considered the main culprit in the decline of Roman civilization, its presence in the Roman water distribution system water is still worthy of consideration as a major public health problem. The Archaeology of Portus course will introduce some of the methods employed in this research.

By measuring the isotopic composition of the lead in the sediments of the docks of the port of Imperial Rome (Portus) and the Tiber, a new study has shown that the piped water of ancient Rome contained up to 100 times more lead than the local water sources. Moreover, fluctuations in the isotopic signal of the lead in the sedimentary deposits studied indicate that they are closely linked to major historical events that affected Rome and its water distribution systems in late antiquity.

This research was conducted by a multidisciplinary team of researchers in Lyon involving the Laboratoire d’Environnement, Ville, Société (EVS, CNRS/Lyon2/Lyon3/UJM/INSA de Lyon/ENS de Lyon/ENTPE), the Laboratoire de Géologie de Lyon Terre, Planète, Environnement (ENS de Lyon /Université Claude Bernard Lyon 1/CNRS) and the Laboratoire Archéorient (CNRS/Université Lumière Lyon 2) of the Maison de l’Orient et de la Méditerranée – Jean Pouilloux. This study was published in the Journal Proceedings of the National Academy of Sciences (PNAS) in April 2014.

Research paper: http://www.pnas.org/content/111/18/6594.abstract

Guardian link: http://www.theguardian.com/science/2014/apr/21/ancient-rome-tap-water-contaminated-lead-researchers

Maggy says:

May 12, 2014 at 7:40 am

It would be great to think these methods could also be applied closer to home. In the NW of England there are Roman sites such as Chester and Maryport which have avoided post-18th century large scale industrial development and so might be able to yield similar sediments for isotopic analysis.
I’d love to learn more about the lab processes involved in gathering and analysing samples, and hope this will be at least signposted in the course.

Per Baadnes says:

May 12, 2014 at 8:33 pm

I have always thought that water was supplied continuously to Roman cities, continuously as in running all time. I do not know if they had a tap to turn on and off. By this I mean, the accumulation of lead ions would be less than in the analyses sediment. One of the effects of lead poisoning is sterility, another is reduced strength in the muscles in the hands, not likely to bring the Roman empire down. To me it seems quite far fetched to accuse the water, more likely are the length of the border, the organization of the attacker, the weakened military and the like.

May 13, 2014 at 7:26 am

Following on from Per’s point, agreed that modern evidence doesn’t support the idea that lead pipes brought down the Roman Empire, but the recent research allows us to test the hypothesis that urban people at the time had greatly elevated levels of lead in their systems. I have seen for example the remains of huge lead containers (Tullie House Museum, Carlisle, not on display); lead pipes and taps led into houses in places that have survived to a large extent, like Pompeii and Herculaneum. Per is correct that the supply of water into urban centres was continual, flowing by gravity along aqueducts and then into collection/distribution points, and even down to the level of individual neighbourhoods water flowed continually into supply troughs from which ‘the unconnected’ gathered their water. But wealthier people definitely enjoyed indoor plumbing largely based on lead. I suspect that in provinces like Britain, the value of lead piping led later non-urban generations to strip them out and re-use them so they don’t survive for excavation.
Per, there’s a great book by Peter Connolly called The Ancient City that has excellent reconstructions of Roman plumbing based on real examples from Italy – I recommend it and believe you will enjoy it.

Bob says:

May 19, 2014 at 8:19 am

Given that lead accumulates in the body ( particularly bones and teeth) and has been implicated in child IQ impairment I would be interested in any cross correlation with lead analysis in skeletons through time in Portus-has such work been done?

Hazel Dunphy says:

May 20, 2014 at 11:24 pm

Is not water in and around Rome hard which would reduce the lead content in piped water?

Maggy says:

May 21, 2014 at 7:27 am

You’re probably right Hazel, but lead was used in many more applications – even wine storage jars as it made the wine taste sweeter! Sounds like elevated lead content could come from more places than just water supply aqueducts. This is why we need more research!