Duke University researchers unveil the environmental risks posed by lithium extraction at Bolivia’s Salar de Uyuni. Their findings highlight the need for sustainable mining approaches to protect local ecosystems and communities.
Sitting atop Bolivia’s high Andean plateau, the Salar de Uyuni conceals a critical natural resource just below its surface — the world’s largest known lithium deposit. According to the Duke University Nicholas School of the Environment’s Avner Vengosh and doctoral student Gordon Williams, the hidden lithium brines pose significant potential for future sustainable energy but come with substantial environmental concerns.
Currently, lithium extraction methods involve pumping brine from beneath the salt pan and processing it through a series of evaporation ponds.
However, research indicates this extraction could lead to environmental degradation similar to that seen at Chile’s Salar de Atacama, where groundwater depletion and land subsidence were noted as serious concerns.
The researchers have performed an extensive chemical analysis on the wastewater produced during lithium mining at the Salar de Uyuni. Their findings, published in the journal Environmental Science & Technology Letters, reveal high levels of arsenic and other trace elements, bringing attention to the potential risk for local wildlife and the broader ecosystem.
“This arsenic level is extremely high,” Vengosh, the Nicholas Chair of Environmental Quality, said in a news release. “My group has worked all over the world — in Africa, Europe, Vietnam, India — and I don’t think we ever measured that level of arsenic.”
The study recorded arsenic concentrations in evaporation pond brine reaching nearly 50 parts per million, a stark contrast to the 1 to 9 parts per million found in natural brine, and far above the U.S. Environmental Protection Agency’s ecological safety benchmark.
This elevated arsenic poses a threat to local wildlife, particularly species like flamingos that feed on brine shrimp sensitive to arsenic.
“There’s a risk for bioaccumulation,” added Williams, indicating the potential for chemicals to build up in organisms over time with harmful impacts.
The researchers also highlighted the complexities involved in re-injecting spent brine or wastewater back into the lithium deposit to mitigate land subsidence. Inadequate mixing and dilution of lithium resources were cited as significant hurdles, suggesting more research is needed to develop environmentally sound strategies.
“We see lithium as the future for energy security, so we’re trying to analyze it from different angles to ensure sustainable development and supplies,” Vengosh added.
Understanding the dynamics of lithium brine at Salar de Uyuni is crucial, not only for advancing sustainable extraction methods but also for safeguarding the health of neighboring Indigenous communities — a concern that Vengosh, Williams and other Duke University researchers are actively investigating.
As the world increasingly turns to lithium as a reliable energy source, studies like these underscore the importance of balancing resource extraction with environmental stewardship.