Progress with side effects - How lead changed the ancient world
By Nisa Iduna Kirchengast - Editors: Daniel Kunc, Thomas MauerhoferSmall biconical lead object with loop. - © Lower Austrian Provincial Collections
“Like lead on your feet” or ‘heavy as lead’ - sayings that associate the metal lead with heaviness and weight still reflect its special character today. But lead was much more than a metaphor in ancient times: it shaped everyday life and infrastructure, stood for progress and innovation, but was also a health risk.
Lead was transported from the mining regions to the provinces of the Roman Empire in the form of large ingots. In Roman times, the raw material was mined in numerous regions, such as the Balkans, Greece, Asia Minor, Spain, Britain and Germania. In Britain, for example, industrial lead mining began immediately after the Roman conquest by Emperor Claudius (43 AD). Originally closely linked to silver mining, lead itself developed over time into an important raw material that was processed into a versatile material using advanced methods.
Lead was used in construction, for example to clamp stone blocks - an estimated seven tons of lead were used in the Porta Nigra in Trier. In shipbuilding, lead protected wooden hulls from pests, while in water supply it was used to make the famous lead pipes (known as fistulae). In urban centers such as Pompeii in particular, this material played a key role in the distribution of drinking water. Up to twelve parallel lead pipes were used for complex pressure pipes that bridged valleys. Estimates for such projects, such as the Lugdunum water pipeline (Lyon), amount to a requirement of up to 40,000 tons of lead.
In addition to its architectural and infrastructural applications, lead was also used for weights, amulets, identification marks (tesserae) or curse tablets (lat.: defixiones; inscribed lead sheets with supposed damage spells). Lead plays an unusual role in this context. On the one hand, it is soft enough to be easily written on with a metal stylus, and the writing can be removed just as easily by tapping it out. On the other hand, it is characterized by its heaviness, dark color and poisonous properties - characteristics that were already known in ancient times and gave the metal a symbolic connection to the gods. Small lead bullets, known as “sling leads”, were used in the military. Numerous lead finds also come from Carnuntum, such as lead water pipes, lead weights and lead tablets. The demand for lead was so high that it was traded over long distances. Roman lead ingots, which often weighed over 80 kg and bore inscriptions on their origin and date, are now valuable sources for researching ancient trade routes.
Curse panel, originally wrapped around a triangular nail; irregular shape; inscription written in Latin with Greek text parts.- © Lower Austrian State Collections
The health costs of progress
However, Roman lead processing not only left economic traces, but also long-term environmental consequences. Ice core analyses from Greenland show a significant increase in atmospheric lead levels between the 5th century BC and the 3rd century AD, caused by mining and smelting. In addition to its many uses, lead was not without danger. Vitruvius and later Pliny already described the toxic fumes that arose during the processing of the metal. Modern research shows that the widespread use of lead in everyday Roman life - from water pipes and cooking utensils to the refinement and sweetening of wine with so-called “lead sugar” (Latin sapa) - led to considerable damage to health. Archaeological and geological studies also show increased lead concentrations in sediments and fossil soils, which indicate widespread environmental pollution.
exemplar autem ab artificibus plumbariis possumus accipere, quod palloribus occupatos habent corporis colores. namque cum fundendo plumbum flatur, vapor ex eo insidens corporis artus et in diem exurens eripit ex membris eorum sanguinis virtutes. itaque minime fistulis plumbeis aqua duci videtur, si volumus eam habere salubrem. saporemque meliorem ex tubulis esse cotidianus potest indicare victus, quod omnes structas cum habeant vasorum argenteorum mensas, tamen propter saporis integritatem fictilibus utuntur. (Vitruv 8,6,11)
“This may be verified by observing the workmen in lead working, who exhibit a pale complexion; for in pouring lead, the vapors of the metal settle on the various parts of the body, and burn them daily, destroying the vitality of the blood. Water should therefore under no circumstances be passed through lead pipes if we are anxious that it should remain healthy. The fact that the taste of water passed through clay pipes is better is evident in our daily meals: For all those who use silver vessels on their tables still reach for those made of clay, as with these the purity of taste is preserved.”
Chronic lead poisoning had mainly neurological effects. Recent studies suggest that lead exposure lowered the average intelligence quotient of the population by up to three points. Children in particular were affected, which had not only individual but also social consequences: the performance and creativity of Roman society may have been significantly impaired by these cognitive impairments. In addition, there were physical complaints such as kidney damage, high blood pressure and a weakened immune system, which may also have reduced life expectancy and the efficiency of the workforce.
Large numbers of lead motifs in the form of aedicules were found in Carnuntum. They mostly show three female deities who can be identified as Slivanae, companions of Silvanus, or as triviae, i.e. goddesses of crossroads.
Right votive: lead votive in mirror form, left votive: lead votive in aedicula form - © NÖ Landessammlungen, Archäologischer Park Carnuntum (Photo: N.Gail)
Further reading:
G. Kremer - M. Holzner, Do ut des - Bleivotive aus Carnuntum, CarnuntumJb 2012, 2012, 31-69.