Research links Roman Empire air pollution to decline in European IQ

Research suggests that air pollution during the Roman Empire may have caused a decline in IQ across Europe. Ice-core records show a significant increase in atmospheric lead levels from 100 BCE to 200 CE, linked to extensive mining and metal smelting. Children born in this period likely had lead levels in their blood three times higher than today's averages in the US. The study estimates that this exposure could have reduced IQ by 2.5 to 3 points for the population. The findings align with previous studies on lead pollution and its effects. This research is notable for using ice-core data to assess historical pollution and its impact on human health. The study was published in the journal PNAS.