"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."

DRI scientists analyzed Arctic ice core records to reconstruct historical atmospheric lead pollution from Ancient Rome, uncovering a link between lead exposure and cognitive decline. Lead exposure is a significant public health concern,

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.

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

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.

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.