The Romans invented concrete, aqueducts, and the basis of the modern calendar. But their achievements could have been even greater had their brains not been addled by lead poisoning, a study suggests. The University of Oxford has concluded that lead pollution reduced IQ levels by at least two to three points among the European population.
Lead exposure is responsible for a number of adverse health effects, with even relatively low levels affecting cognitive development. To find out how prevalent lead was in the atmosphere during the Roman period , researchers examined three ice core records to identify pollution levels in the Arctic between BC through AD. The team specifically looked at lead isotopes, which can show where the metal originated, in this case from mining and smelting.
Ancient lead pollution stemmed largely from silver mining, whereby the lead-rich mineral galena was melted down to extract the precious metal. For every ounce of silver obtained, this process produced thousands of ounces of lead β much of which was released to the atmosphere. The study found that the resulting pollution began during the Iron Age and reached a peak during the late 2nd century BCE at the height of the Roman Republic. Lead pollution remained high until the Antonine Plague, from to the s CE, which severely affected the Roman Empire.
According to the research, more than kilotons of lead were released to the atmosphere during the nearly year height of the Roman Empire. Although ice core records show that Arctic lead pollution was up to fold higher during the highest historical peak in the early s, the insight gained from this study demonstrates how humans have been affecting their health for thousands of years through industrial activity, the researchers said. Broaden your horizons with award-winning British journalism.
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