Scientists have found the oldest evidence of manmade air pollution buried in an ice cap in the Peruvian Andes.
According to Live Science, authors of a study published in the journal Proceedings of the National Academy of Science believe the pollutants originated in the Bolivian mountain Potosí's silver mines.
"This evidence supports the idea that human impact on the environment was widespread even before the industrial revolution," study co-author Paolo Gabrielli, a research scientist at the Byrd Polar and Climate Research Center at Ohio State University, said in a press release.
Found in 16th century Spanish silver mines in Peru, the traces' origins would have been hundreds of miles away if they did in fact begin in Bolivia. But the city of Potosí has a well-documented and celebrated industrial history in South America for its silver.
"There is a long pre-industrial history of mining in Peru and Bolivia," Gabrielli told Live Science. "Our study demonstrates that since the colonial time, mining and metallurgic activities performed by the Spanish did also have an impact on very distant areas."
The team of scientists used an instrument called a mass spectrometer, which can measure chemicals in number and type based on a single sample. For their study, Gabrielli and his team looked for antimony, arsenic, bismuth, molybdenum and lead in the ice cap.
"The fact that we can detect pollution in ice from a pristine high altitude location is indicative of the continental significance of this deposition," Gabrielli said in the release. "Only a significant source of pollution could travel so far, and affect the chemistry of the snow on a remote place like Quelccaya."
