Ancient Greece produced the earliest records of democracy, western philosophy—and, it turns out, lead pollution, Euronews reports.
Researchers studying sediment cores recovered from mainland Greece and the Aegean Sea have found the oldest known evidence of lead pollution in the environment dating to around 5,200 years ago.
That’s 1,200 years older than the previous earliest recorded lead pollution, which was found in a peat bog in Serbia.
The research results were published in the journal Communications Earth and Environment.
In antiquity, lead was released into the atmosphere as a byproduct of smelting ore for copper and silver. The toxic metal later condensed as dust and settled onto the soil.
The site with the earliest signs of lead contamination is located in northeastern Greece, near the island of Thasos. Prior archaeological evidence suggests Thasos was one of the region’s most significant sites for silver mining and metalwork.
The researchers found that levels of lead contamination remained fairly low and localized in ancient Greece, considered the cradle of European civilization, throughout the Bronze Age, the Classical period, and the Hellenistic period.
But around 2,150 years ago, the researchers detected “a very strong and abrupt increase” in lead emissions caused by human activities across Greece, said co-author Andreas Koutsodendris at Heidelberg University.
Around that time, in 146 BC, the Roman army conquered the Greek peninsula, transforming the region’s society and economy.
As Roman trade, colonies, and shipping expanded across the Mediterranean and Black Seas, demand for silver coins grew. This required smelting, which released lead, said Koutsodendris.
Later, the Roman Empire used lead for tableware and for construction, including pipes.