miércoles, 23 de abril de 2014

Were Ancient Romans poisoned by lead? (Italy)

It is universally accepted that using lead for domestic water supply and distribution presents a major health hazard. The ancient Romans were unaware of these risks – even sweetening wine with lead – but the water pipes and lead tanks may have had an impact on the ruling elite, who accessed this water.

A historical record of lead pollution

Some historians argue that lead poisoning plagued the Roman elite with diseases such as gout, and may even have hastened the Empire’s fall. Recently, a scientific team investigated just how contaminated Roman tap water was likely to be, in a new report published in the Proceedings of the National Academy of Sciences.
How far the gigantic network of lead pipes used in ancient Rome compromised public health in the city is unknown. However, lead isotopes in sediments from Portus – the harbour of Imperial Rome  – register the presence of a strong anthropogenic component during the beginning of the Common Era and the Early Middle Ages.
The team cored sediments downstream from Rome in the harbour basin at Portus, and from a channel connecting the port to the Tiber River. The researchers compared the lead isotopes in their sediment samples with those found in preserved Roman piping to create a historical record of lead pollution flowing from the Roman capital.

Understanding the harbour

The core samples charted a rise and fall in the concentrations of lead that, when mapped against C14 dates, were able to match known historical events and disruptions. Transitions between sample units may be correlated with the initial excavation of the Trajanic basin (c. AD 112), the continued use of the port during the third century, the gradual fortification and contraction of the port in the later fifth and earlier sixth centuries, and the transition to the post-Byzantine period.
The later fifth and sixth century spike in lead isotopes may be connected to Belisarius’ fixing the abandoned aqueducts of Rome at the end of the Gothic Wars (535–554 AD). Byzantine repairs of the water distribution system may have flushed out massive amounts of corrosion products from abandoned lead pipes in which water may have stagnated for protracted lengths of time.
Although an absolute relationship cannot be proved, the levels of lead recorded from the sediment cores from Portus do seem to show some form of relationship with historically documented events such as the struggle for the control of the port between Gothic and Byzantine forces (AD 536–552) and the damages inflicted to the water distribution system during the Arab sack of Rome in the mid-ninth century.

The effect of lead on a population

Kristina Killgrove, bioarchaeologist at the University of West Florida, who was not involved in this study, carried out an extensive examination of how lead affected the Roman Imperial population, by looking the presence of lead isotope in skeletons from the ancient cemetery at Gabii.
She comments, “Did lead poisoning cause the fall of the Roman Empire?  Probably not, [but] there was increased lead production in the Roman Empire, … however the data simply doesn’t support a conclusion of high lead concentration in the entire population.”

Source: Past Horizons: http://www.pasthorizonspr.com/index.php/archives/04/2014/were-ancient-romans-poisoned-by-lead

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