History's hidden lead crisis
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Human-caused lead pollution began over 5,000 years ago - much earlier than thought.
New research reveals that lead contamination in the Aegean Sea started around 5,200 years ago, during the rise of ancient Greek civilisations.
This finding, by German and Greek scientists, pushes back the timeline of human-induced environmental damage by 1,200 years.
Published in Communications Earth & Environment, the study shows that early agropastoral societies already influenced ecosystems.
Researchers analysed marine sediment cores from the Aegean Sea and a peat core from Tenaghi Philippon in northeastern Greece, uncovering the world’s earliest known evidence of human-caused lead pollution.
“The earliest impact was confined to the close vicinity of settlements,” the study notes.
However, even these early mining activities had environmental effects beyond local areas.
A sharp rise in lead pollution occurred around 2,150 years ago, linked to the Roman Empire’s expansion into Ancient Greece.
This period saw increased mining of gold and silver for coinage, alongside widespread deforestation and agricultural growth. These activities significantly impacted both land and sea environments.
Lead levels from both marine and terrestrial sediments indicate the Roman period marked a key shift.
The Tenaghi Philippon core showed pollution evidence predating similar records from Greenland ice cores and Balkan peatlands.
“Our data demonstrate a marked increase in lead pollution at 2,150 years BP that left an imprint across terrestrial and marine settings of the Aegean region,” said Dr Andreas Koutsodendris, one of the lead researchers.
This pollution surge reflects societal shifts, with resource extraction intensifying to support growing economies. Pollen analysis also shows extensive deforestation tied to agriculture and mining.
The study challenges the view that marine pollution is a modern issue, showing that human activities have impacted marine environments for millennia.
