Ancient Romans: Victims of Their Own Industrial Pollution

Research indicates that lead exposure from Roman silver mining may have caused a decline in intelligence across the empire, marking an early instance of industrial pollution.

Roughly 2,000 years ago, the Roman Empire experienced a golden era, but beneath the surface, a troubling environmental problem was developing. A recent study published in the journal Proceedings of the National Academy of Sciences has found that lead pollution may have significantly impacted public health and cognitive abilities during this time.

Beginning in 27 B.C., during the Pax Romana, a period characterized by relative peace and economic prosperity, the Roman Empire expanded its territories across Europe, the Middle East, and North Africa. The economy relied heavily on silver coinage, necessitating extensive mining operations. However, the extraction of silver invariably produced a massive amount of lead — for each ounce of silver, approximately 10,000 ounces of lead were released into the environment, according to Joseph McConnell, the lead author of the study and an environmental scientist at the Desert Research Institute.

The dangers of lead exposure are well-documented, with no known safe threshold, as highlighted by neurotoxicologist Deborah Cory-Slechta from the University of Rochester Medical Center, who was not part of the study. The researchers found traces of lead in ice samples from Greenland and Russia, which they believe originated from Roman mining activities. The lead particles traveled through the atmosphere, eventually depositing in the Arctic as snowfall.

This research not only sheds light on the potential cognitive decline experienced by the Roman population due to lead exposure but also serves as an early reminder of the detrimental effects industrialization can have on human health and the environment.