Lead pollution resulting from Roman gold extraction in northwestern Spain

A 4000-year record of lake sediment geochemistry from Laguna Roya, near the UNESCO World Heritage Site Las Médulas, reveals that lead pollution during Roman gold extraction (300 BC to AD 120) was twice as high as modern levels. This challenges the assumption that pre-industrial civilizations had minimal environmental impact. The study used trace metal concentrations in sediments to document atmospheric deposition linked to mining and smelting activities. Additional spikes in antimony and bismuth between AD 1500-1700 suggest post-medieval mining, while industrial-era lead pollution peaked in the late 20th century before declining due to the phase-out of leaded gasoline.

Hillman, A. L., Abbott, M. B., Valero-Garcés, B., Morellon, M., Barreiro-Lostres, F., & Bain, D. J. (2017). Lead pollution resulting from Roman gold extraction in northwestern Spain. The Holocene, 27(10), 1465–1474. https://doi.org/10.1177/0959683617693903