Environmental pollution Lead from silver extraction cost ancient Romans up to three IQ points
Lead pollution is likely to have cost the people of Ancient Rome two and a half to three IQ points. This is the conclusion reached by an international research team with Swiss participation in a new study.
07.01.2025, 11:08
07.01.2025, 11:09
SDA
Using new data from three ice cores from the Arctic, the researchers calculated the lead concentrations in Ancient Rome and their effects on humans for the study published in the scientific journal "PNAS", as the University of Vienna announced on Tuesday. Researcher Sandra Camara-Brugger from the University of Basel was also involved in the study, which was led by Joe McConnell from the US Desert Research Institute (DRI).
In Roman times, a great deal of lead-containing ore was needed to obtain the coveted silver. In the course of the processing technology of the time, lead was also released into the air in large quantities. According to research findings, more than 500 kilotons of lead were released into the atmosphere during the almost 200-year heyday of the Roman Empire.
More lead, less IQ
The scientists then used findings on the correlation between blood-lead concentrations and performance in intelligence tests: in view of this, it can be assumed that the pollution probably cost the ancient Romans an average of two and a half to three IQ points over the entire empire. In mining regions, the drop in intelligence could have been significantly higher.
"A reduction in IQ of two to three points doesn't sound like much, but if you apply that to the entire European population, it's significant," DRI researcher Nathan Chellman was quoted as saying in the press release.
According to the researchers, almost 200 years of increased lead pollution could also have contributed to the fact that the Antonine Plague cost the lives of around five to ten million people and ended the rather peaceful episode, the study authors believe.
