Toxic air pollution in Europe started with ancient Romans

Back in times past the environment was still unpolluted as ancient peoples, destructive as they might have been in some respects, had a rather low impact on the planet as a whole.

Or so a common view goes. But is it true? Not necessarily.

Take a new study whose authors note that mining activities by ancient Romans, those masters of engineering, increased concentrations of atmospheric lead tenfold over time. This led to far more severe levels of air pollution on the continent than previously thought for centuries.

The scientists discovered this by analyzing ice cores from glaciers on Mont Blanc in France where people were already mining metals as far back as the 6th millennium BCE. But then along came the Romans, who set about mass-producing lead for their water pipes in large-scale plumbing, household items and other objects.

The researchers discovered two spikes, centuries apart, in concentrations of trace metals in some of Mont Blanc’s ice that was formed in ancient times: one was deposited in the 2nd century BCE and the other in the 2nd century CE. The Romans’ extensive mining and smelting of heavy metals for half a millennium between 350 BCE and 175 CE released large amounts of toxic fumes into Europe’s air.

Even in relatively small amounts, lead is an extremely toxic environmental pollutant, which can cause a variety of severe health problems in people, especially children. Ancient Romans were unaware of this, of course, and so they carried on polluting their environment and slowly poisoning themselves in the process.

Alpine ice samples show that lead emissions during antiquity surpassed the natural level of lead in the environment of Europe by a factor of 10, says Michel Legrand, an atmospheric scientist at the Université Grenoble Alpes in Grenoble in France who was a co-author of the study.

The results of that were stark. “For comparison, recent human activities related to the use of leaded gasoline in Europe enhanced the natural lead level by a factor of 50 to 100,” Legrand explains. “Thus, the pollution by the Romans is five to 10 times less than that due to the recent use of gasoline but it took place for a long period of time – several centuries instead of 30 years of leaded gasoline use.”

Previously, other researchers discovered lead in an ice core taken in Greenland that formed during the Roman period. It showed that Roman mining activities sent pollution far and wide across Europe, even to remote inhospitable areas where no Roman ever set foot.

In other words, people started polluting their environments long before the Industrial Revolution turned pollution into an industrial-scale byproduct. “Our ultimate goal,” Legrand says, “is to show the man-made impact on the atmosphere for millennia now.”