Byrd Polar and Climate Research Center researchers have discovered the earliest evidence of large-scale human-produced air pollution dating to the Spanish conquest of the Incas during the 1500's.

In the 16th century, during its conquest of South America, the Spanish Empire forced countless Incas to work extracting silver from the mountaintop mines of Potosí, in what is now Bolivia—then the largest source of silver in the world. The Inca already knew how to refine silver, but in 1572 the Spanish introduced a new technology that boosted production many times over and sent thick clouds of lead dust rising over the Andes for the first time in history.

“This evidence supports the idea that human impact on the environment was widespread even before the industrial revolution,” said Paolo Gabrielli, a research scientist at the Byrd Polar and Climate Research Center at Ohio State and corresponding author of the study.

Lonnie Thompson, Distinguished University Professor of Earth Sciences at Ohio State and co-author of the study, called the find “another keyhole into the past of human activity in that part of the world,” and suggested that further investigation could ultimately help us better understand the fate of pollution circulating in the atmosphere today.

For further details, please see the OSU News website.