A recent study conducted by geoscientists from Heidelberg University has uncovered the earliest known evidence of environmental lead contamination in the Aegean region. By analyzing sediment cores from the seabed and coastal areas surrounding the Aegean Sea, researchers have determined that human activities began polluting the environment with lead approximately 5,200 years ago—well before previously recorded evidence of such contamination.

This discovery not only extends the timeline of human-induced environmental pollution but also provides crucial insights into the socio-economic transformations of ancient civilizations, particularly the impact of the Roman conquest of Greece.

The Aegean region is known as the birthplace of some of Europe’s earliest civilizations, including the Minoans and Mycenaeans. Understanding the environmental impact of human activity in this historically rich area provides valuable insights into the evolution of ancient societies. To investigate this, the research team analyzed 14 sediment cores from the Aegean Sea and surrounding coastlines, with one core from a peat bog providing the earliest known evidence of lead contamination in the environment.

Lead contamination Aegean
Left: Position of the Aegean region (black box) within the North Atlantic realm and locations of the Pb records from Crveni Potok and NGRIP ice cores in Greenland. Right: Locations of the studied cores (closed blue and green circles) in the Aegean region, and selected previously published palynological records (open green circles) that are referred to in the discussion. Locations of known Pb ore deposits adapted from the OXALID database are also shown (closed violet circles). Andreas Koutsodendris et al.

This sediment core revealed lead traces dating back to around 5,200 years ago, predating the previously known earliest evidence of lead pollution by approximately 1,200 years. The contamination was likely the result of early metallurgical activities, particularly those related to silver production, which is known to release lead as a byproduct. The presence of lead in these ancient sediments serves as an important marker of early industrial activity and economic shifts.

According to Dr. Andreas Koutsodendris of Heidelberg University’s Institute of Earth Sciences, the increase in lead levels over time correlates with significant economic and societal changes. Lead pollution levels surged around 2,150 years ago, a period that coincides with the Roman conquest of Greece.

By analyzing pollen samples within the sediment cores, researchers were able to reconstruct patterns of vegetation and land use. The data indicate that this period was marked by widespread deforestation and intensified agricultural activity. These changes align with historical records of Roman economic expansion and resource exploitation in the region.

Lead contamination Aegean
Sediment cores sampled from the Aegean Sea serve as natural environmental archives, offering insights into the impacts of early human activity on ecosystems. Credit: Bertil Mächtle

Professor Jörg Pross, a leading researcher in paleoenvironmental dynamics, emphasized that the simultaneous rise in lead pollution and land-use changes reflects a transition from agrarian economies to monetized economies. The Roman conquest facilitated increased mining activities for gold, silver, and other valuable metals, with smelting operations contributing heavily to lead emissions. The extraction and processing of these minerals were highly dependent on wood, further exacerbating deforestation.

Significantly, the study also provides the oldest known record of lead contamination in oceanic sediments caused by human activity. Prior to this discovery, marine lead pollution was primarily linked to more recent industrial advancements. The findings from the Aegean seabed establish that human-induced environmental degradation through metal production was occurring on a large scale over two millennia ago.

The sediment cores analyzed in this study were collected during research expeditions aboard the METEOR and AEGAEO vessels between 2001 and 2021. The project was supported by the German Research Foundation (DFG) and the European Union, with additional funding for continued research efforts. Alongside the Heidelberg team, scientists from Berlin, Frankfurt, Hamburg, Hohenheim, Tübingen, and Greece contributed to this groundbreaking study.

SOURCES

Universität Heidelberg

Koutsodendris, A., Maran, J., Kotthoff, U. et al. Societal changes in Ancient Greece impacted terrestrial and marine environments. Commun Earth Environ 6, 25 (2025). doi.org/10.1038/s43247-024-01921-7

  • Share on:

Discover more from LBV Magazine English Edition

Subscribe to get the latest posts sent to your email.

Something went wrong. Please refresh the page and/or try again.

Follow LBV Magazine on Google News