In Roman times, lead pollution wreaked havoc on IQ – rts.ch

Using data from three ice cores taken in the Arctic, scientists calculated lead concentrations in ancient Rome and their effects on humans, according to this study published in the American journal PNAS.

To obtain the silver so coveted in Roman times, it was necessary to melt a large quantity of ore – galena – containing lead.

With the processing techniques of the time, for every ounce of silver obtained, this process produced thousands of ounces of lead, much of which was released into the atmosphere.

According to the research results, more than 500,000 tonnes of lead were returned there during the almost 200 years of the Roman Empire’s heyday. (read box)said Tuesday the University of Vienna, which contributed to this work.

Lead pollution for 200 years

Scientists examined the correlation between blood lead levels and intelligence test scores (read box). And their inference is that pollution probably cost the ancient populations of ancient Rome two and a half to three IQ points on average across the entire Empire. In mining regions, the decline in intelligence may even have been significantly greater.

“A drop in IQ of two to three points doesn’t seem like a lot, but if you apply it to the entire European population, it’s considerable,” notes Nathan Chellman, a researcher at the American Desert Research Institute (DRI), cited in the communiqué.

According to the research team, intensifying lead pollution over nearly 200 years may further have contributed to the deaths of an estimated five to ten million people during the “Antonine Plague”, likely an outbreak of smallpox. which occurred at the end of the 2nd century AD. Researcher Sandra Camara-Brugger from the University of Basel also participated in this study led by Joe McConnell at the DRI.

>> Read also: Lead may play an underestimated role in deaths from cardiovascular diseases

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