The earliest traces of lead pollution the researchers identified were 5,200 years old. Joe Daniel Price via Getty ImagesNew research has found that ancient Greece may harbor the oldest known evidence of lead pollution.After analyzing sediment cores from Greeces mainland and the Aegean Sea, scientists identified traces of lead contamination that date back more than 5,000 years. The discovery suggests that human activities were causing lead pollution 1,200 years earlier than previously thought.The lead emissions followed the development of smelting technologies, which produced metals like silver, according to a recent study published in the journal Communications Earth & Environment.Silver was used for jewelry, for special objectsbut it wasnt found in a pure state, co-author Joseph Maran, an archaeologist at Heidelberg University, tells Christina Larson of theAssociated Press.The smelting process released lead into the environment, and traces eventually became embedded in the soil, where todays scientists can study them.The earliest traces of lead pollution the researchers identified were 5,200 years old. They were found in a peat bog in northeastern Greece near the island of Thasos, an ancient hub for silver mining and metalwork.Peat cores dont receive any fluvial [river] input, so its only atmospheric dust that settles into this environment, co-author Andreas Koutsodendris, a scholar at Heidelberg Universitys Institute of Earth Sciences, tells Peter de Kruijff of the Australian Broadcasting Corporation.The researchers found that another sharp increase occurred about 2,150 years ago, which coincides with the Roman conquest of the Greek peninsula in around 146 B.C.E. Following this victory, the Romans claimed for themselves the regions wealth of resources, says Maran in a statement.The Roman expansion drove a new demand for silver to mint currency, leading to increased smelting and greater environmental contamination, as Koutsodendris tells the AP. The widespread use of lead for construction, coin production and even tableware further contributed to emission levels.The new research complements previous studies, such as ice core analyses from Greenland, which had already suggested high lead emissions during the Roman era. As Nathan Chellman, an environmental scientist at the University of Nevada at Reno who wasnt involved in the research, tells the AP, the new study adds a more specific and local picture to how lead levels changed.Beyond pollution, the findings highlight the broader environmental consequences of resource exploitation. The Romans expanded mining operations, extracting vast quantities of gold, silver and other metals. Smelting these metals required the Romans to gather large amounts of wood, which also contributed to widespread deforestation and land degradation, per the study.By analyzing the sediment cores, the researchers were also able to track vegetation development in the region, revealing shifts in land use over time.The combined data on lead contamination and vegetation development show when the transition from agricultural to monetary societies took place and how that impacted the environment, says Jrg Pross, a scholar at Heidelberg Universitys Institute of Earth Sciences, in the statement.Get the latest stories in your inbox every weekday.Filed Under: Ancient Greece, Gold, Greece, History, New Research, Pollution