Ancient Greece Was Site of World’s Earliest Lead Pollution, Study Finds

Ancient Greece, famed for its contributions to democracy and philosophy, was also the unexpected cradle of significant lead pollution, The Associated Press reports, citing new research.

Scientists have discovered the oldest known evidence of environmental lead contamination dating back approximately 5,200 years, pushing back the previously recorded timeline by more than a millennium.

The study, published Thursday in the journal Communications Earth and Environment, reveals that lead pollution began as a byproduct of smelting ore to extract copper and silver. This toxic metal, released into the atmosphere, eventually settled as dust onto the soil.

“Silver was highly valued for jewelry and special objects, but it wasn’t found in a pure state,” explained Joseph Maran, an archaeologist at Heidelberg University and a co-author of the study.

He noted that silver was typically mined in ores that also contained lead.

The earliest signs of this pollution were discovered in northeastern Greece, near the island of Thasos, which archaeological evidence suggests was a major hub for silver mining and metalwork. While the contamination levels remained relatively low and localized throughout the Bronze Age, the Classical period (known for figures like Socrates and Plato) and the Hellenistic period, a dramatic shift occurred around 2,150 years ago.

The researchers detected “a very strong and abrupt increase” in lead emissions caused by human activities across Greece at that time, said Andreas Koutsodendris, also at Heidelberg University and a co-author of the research.

This surge in pollution coincides with the Roman conquest of Greece in 146 B.C. The Roman Empire’s expansion across the Mediterranean and Black Seas spurred a massive increase in demand for silver coins. This demand led to increased smelting activity, which released large quantities of lead into the atmosphere. The Romans also utilized lead for tableware and construction, further contributing to the pollution.

Previous research, including analysis of Greenland ice cores, had indicated high levels of lead in the Northern Hemisphere during the Roman era. However, this new study provides a more detailed and localized picture of how lead levels fluctuated within Greece.