Cleaning up contaminated mines with plants and fungi

May 06, 2019
IDRC/Bartay

Ebenezer J.D. Belford, a scientist at Kwame Nkrumah University of Science and Technology in Kumasi, Ghana, was researching how plants can help reclaim mining sites, when to his surprise, a colleague informed him that a Canadian was doing the same. “Here I was in Ghana, working on the same topic as Sharon Regan in Canada,” he said.

The two researchers contacted each other to develop a successful proposal to IDRC’s Canada-Africa Research Exchange Grants program in 2014 (managed by the Social Sciences and Humanities Research Council) to set up a joint lab at Queen’s University, in Kingston, Ontario. “Without [the IDRC grant], we wouldn’t have been able to get started together at all,” says Belford.

Since then, the two biotech researchers have been collaborating to create plants that can handle the hard work of cleaning up contaminated mine sites. Their joint research uses fungi to boost the ability of plants to absorb heavy metals in mine tailings (the soil left behind at mine sites). The heavy metals found in these tailings make land unsuitable for agriculture, they pollute watersheds, and they pose threats to human health. Together, Belford and Regan began engineering plants that would help remove mercury, cadmium, arsenic, and lead from the soil at abandoned mines.

Protecting people and changing policy

Regan travelled to Ghana in 2015 and was shocked to see that abandoned mine sites are generally open to the public. At a defunct AngloGold mine in Obuasi, for example, she saw groups of people walking with children on the contaminated land. Many were looking for gold at the abandoned site.

“Although Canada and Ghana both have significant challenges when dealing with heavy metal contaminated sites, the impact on human health is felt even more in Ghana,” Regan said. “For me, having seen firsthand how people are living near these contaminated sites makes our research seem even more important.”

The site she visited was naturally overgrown with senna (senna occidentalis), which is why Belford focused on boosting its ability to leach heavy metals from soil. “We are very motivated and hope we can come out with something that will benefit everybody, to ensure the lands are cleaned properly,” said Belford.

The cleaning power of plants

The two scientists began testing how the senna plant, the small flowering shrub that Belford had been working with in Ghana, could gain an edge at leaching contaminants from old mine sites. Regan was thrilled when early test results showed that fungi enhanced the biomass and leaching capacity of senna by two to three times. Even so, tests must be repeated to determine the impact of the enhanced plants on a variety of different contaminants.

A surprise finding also occurred while Belford was conducting research in Canada. During a field trip with Regan to Kam Kotia, a former copper mine outside Timmins, Ontario, the scientists determined that the same fungi that boosts senna plants in Ghana also helps the roots of poplar trees clean the soil. This has now become the primary focus of Regan’s research in Canada.

Ongoing research helps Ghanaian students

Their research has attracted at least one Ghanaian and two Canadian graduate students. Working with Regan at her Queen’s University biotech lab, the students are spending long hours testing and retesting root cultures and purifying the fungi that are needed to create contaminant-leaching super plants.

A former student of Belford’s from Ghana, Joseph Quagraine, is now completing a Master of Science at Queen’s after working with Regan since 2015. His work was supported by a federal grant that was obtained after the initial research funded by IDRC’s small grant ended. “That little grant kick-started a whole lot in my lab, and a whole lot for students,” Regan said.

In the spring of 2019, Regan’s lab will benefit from a CA$1.65 million grant from the Natural Sciences and Engineering Research Council that will allow her to work with two graduate and one or two undergraduate students each year for the next six years. She expects some of the students will be Ghanaian — thus continuing her collaboration with Belford. “The IDRC grant was a unique opportunity to build a new and long-term research collaboration with a like-minded researcher in Ghana,” she said.