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Desert Research Institute Study Finds Lead Pollution During Roman Empire's Pax Romana May Have Caused 2 to 3 Point IQ Reduction in Europe

Jan 7, 2025, 01:36 PM

A recent study by the Desert Research Institute, published in the Proceedings of the National Academy of Sciences, suggests that lead pollution during the Roman Empire may have led to a widespread decline in IQ across Europe. Researchers Joe McConnell and Nathan Chellman analyzed Arctic ice cores to identify lead pollution levels from 500 BCE to 600 CE, covering the rise and fall of the Roman Empire. During the peak of the Roman Empire, known as the Pax Romana, lead pollution was linked to a 2 to 3 point reduction in IQ among the European population. This pollution primarily stemmed from the mining and smelting of silver, which released significant amounts of lead into the atmosphere, with more than 500 kilotons of lead emitted during the nearly 200-year height of the empire. The study highlights the long-term cognitive impacts of industrial lead exposure, with researchers noting that such pollution affected the entire population, including elites and non-elites alike, and that young children during this period had 2.4 micrograms per decilitre of lead in their blood.