Using modern evidence of lead pollution and its health effects, the international team calculates that lead exposure in the Roman golden age could have caused a population-wide drop in IQ of about 2.5 to 3 points per person. And that goes for most of the Roman Empire, including its provinces of Gaul, northwestern Africa, Iberia, and Britannia.

A study analyzing Arctic ice cores reveals that lead pollution during the Roman Empire's height contributed to an estimated 2-3 point IQ decline across Europe.

New research finds that pollution from ancient silver and lead mining during the Roman Empire resulted in lowered intelligence across Europe.

Researchers say the massive expansion of mining and the processing of metal ores caused airborne lead pollution to soar during the peak of the empire, leading to an estimated 2- to 3-point drop in IQ

"A 2 to 3 points lower IQ doesn't sound like much, but when you apply that to the entire European population, it's quite a lot."

The mass production of silver coins in the Roman Empire had an unintended effect: spewing so much lead into the atmosphere that it may have lowered citizens’ IQs.

It was during the period known as the Pax Romana, a time of stability in the Roman Empire that lasted for about two hundred years between 27 BC and 192 AD. Mining and smelting operations throughout Europe were likely a a source of lead contamination,

Researchers measured lead pollution and its impact on human health through Arctic ice-core samples. View on euronews