Scientists find evidence of human air pollution dating back to 1500s


The Adnes is the longest continental mountain range in the world stretching from Venezuela to Argentina. (Michael McDonough/Flickr)
The Adnes is the longest continental mountain range in the world stretching from Venezuela to Argentina. (Michael McDonough/Flickr)

Nick Fetty | February 10, 2015

Researchers have recently discovered evidence of air pollution believed to be from 16th century silver production in Bolivia.

The research team was led by Ohio State University professor Paolo Gabrielli with OSU’s Byrd Polar and Climate Research Center. The researchers discovered an imprint of smog high in metal content in an Andean ice cap in Peru but the source of the pollution is likely hundreds of miles east in present-day Bolivia.

The air pollution was believed to come from to come from silver refineries in the mountain town of Potosí. Prior to Spanish colonization, the Inca people mined silver in the area and at one point Potosí was the silver mining capital of the world. However with Spanish colonization came more efficient methods for mining silver which in turn led to greater amounts of air pollution. Much of the pollution from the silver mines consisted of lead, arsenic, and other materials and was believed to have occurred during between the 16th and 18th centuries.

The article was published in Proceedings in the National Academy of Sciences. The authors conclude: “This anthropogenic pollution of the South American atmosphere precedes the commencement of the Industrial Revolution by ∼240 y(ears).” Some scientists say that human-caused air pollution – “though agriculture, mining, fossil fuel production and other industrial activities” – has put us in a period known as Anthropocene. However scientists debate about when exactly this period began and Gabrielli’s recent findings would suggest that the period started earlier than previously thought.

The research was funded by the National Science Foundation (NSF) Paleoclimate.

Journal features ISU research on agriculture and climate change


This farmer utilizes contour farming and conservation tillage techniques on his Warren County farm in 2011. (Wikimedia)
This farmer utilizes contour farming and conservation tillage techniques on his Warren County farm in 2011. (Wikimedia)

Nick Fetty | December 11, 2014

The most recent issue of the Journal of Soil and Water Conservation includes several articles by Iowa State University researchers focused on ways that climate change is affecting agriculture.

Researchers and graduate students in from Climate and Corn-based Cropping Systems Coordinated Agricultural Project contributed to most of the articles in the recent issue. The project, known simply as the Sustainable Corn Project, is based at Iowa State University and is funded by the U.S. Department of Agriculture. Of the 20 reports in the recent journal issue, 14 were authored by researchers with the Sustainable Corn Project.

One of the reports analyzed the effects cover crops have on nitrous oxide emissions, concluding that cover crops increased nitorus oxide levels in 60 percent of published observations. The authors point out that certain variables could have affected the reaction between the cover crops and nitrous oxide emissions including “fertilizer N(itrogen) rate, soil incorporation, and the period of measurement and rainfall.”

The Sustainable Corn Project is a collaboration between 10 Midwestwen land-grant universities: Iowa State University, Lincoln University (MO), Michigan State University, Ohio State University, Purdue University, South Dakota State University, University of Illinois,  University of Minnesota, University of Missouri, and University of Wisconsin. Roughly 160 scientists, engineers, educators, and students work with more than 200 farmers on this project.