Ancient Greece, famous for its contributions to democracy and philosophy, is now linked to the earliest recorded case of environmental lead pollution. Researchers from Heidelberg University analyzed sediment cores from mainland Greece and the Aegean Sea, finding lead contamination dating back 5,200 years. This discovery predates the previously known oldest lead pollution, found in a Serbian peat bog, by 1,200 years. In ancient times, lead was released into the air when ores were smelted to extract copper and silver. This toxic metal then became dust and settled into the soil. The study, published in Communications Earth and Environment, identified the earliest traces of lead pollution near Thasos, an island in northeastern Greece known for silver mining and metalwork. Archaeological evidence shows that lead pollution stayed minimal and localized during the Bronze Age, Classical period, and Hellenistic period.

A sharp increase in lead emissions occurred around 2,150 years ago, during the Roman conquest of Greece in 146 B.C. Becoming part of the Roman Empire brought economic and societal shifts. The growing demand for silver coins led to more smelting, releasing greater amounts of lead into the environment. Additionally, Romans used lead widely in construction, such as in pipes and tableware. This study gives a local view of historical lead pollution, supporting earlier research on Greenland ice cores.