Accidental Chemist: Alum Pablo Pastén’s Career in Chemistry Began at Northwestern

In a recent profile for Chemical and Engineering News, alum Pablo Pastén credits Professor Jean-François Gaillard for sparking his interest in chemistry. 

As a Ph.D. student at Northwestern University, Pastén never thought he’d become a chemist. He originally trained as a civil engineer at the Pontifical Catholic University of Chile (UC). But a few hours in Jean-François Gaillard’s lab changed everything. 

Gaillard commented on Pastén’s journey—from Northwestern Ph.D. student to lead researcher for the Center for Sustainable Urban Development (CEDEUS) in Chile. 

“A lot of engineering students want to get out of chemistry because it’s too complicated. It has a bad reputation,” Gaillard said in Pastén’s profile. Although Pastén was not a chemist by training, Gaillard thought he had gained the title after hours spent in the lab doing research for Pastén’s Ph.D.

Using geochemistry to address societal challenges and influence public policy, Pastén has been researching the environmental impact of mining in Chile, specifically tailings or waste created after ore is processed. Tailings often contain toxic elements, including heavy metals and other chemicals that can leach into water and soil.

When Pastén and his team visited an urban development built next to abandoned tailing ponds in Copiapo, they learned that the community was concerned about nearby tailings. When they analyzed road dust samples with a portable X-ray fluorescence spectrometer, they found alarming levels of copper, lead, and zinc that exceeded international guidelines for residential soil. In 2022, they published these findings, reviving an inactive discussion on Chile’s soil framework law. 

Along with his role at CEDEUS, Pastén teaches environmental chemistry to students in the Department of Hydraulic and Environmental Engineering at the Pontifical Catholic University of Chile.