It was used in the aftermath of the Chernobyl Nuclear disaster during the 1990s. Now research is underway in South Africa that suggests that hemp might be able to clean up some of the most devastated areas of earth—namely South African gold mines.
In a landmark study, funded by the University of the Witwatersrand in South Africa, a graduate student, Tiago Campbell, a master’s degree candidate in environmental science, is studying phytoremediation as a possible way to regenerate over 400 kilometres of land in the Gauteng, Free State and North West provinces.
This is an area of the planet known for several things. It is one of the richest gold deposits in the world (and has been since it was first discovered). Mining got its start in South Africa in 1852 (copper not gold), but the rush has hardly abated since then. In the 1860s, two of the world’s largest diamonds, including the 83-carat Star of South Africa (aka the Cullinan I diamond which sits in the Queen of England’s gold sceptre) and the 21-carat Eureka diamond were unearthed, which predictably, set off a precious metals and gemstones rush in the country.
Unsurprisingly, it is also a place where several of the top 10 world’s deepest mines are located including the deepest in the world, Mponeng Gold Mine, which stretches up to 4.27 km (just over two miles) below the earth, the second deepest mine, Driefontein Mine (3.42km deep), the third deepest mine (Kusasalethu Gold Mine), 3.38 km deep, the Moab Khotsong Gold Mine, the world’s fourth deepest (at just over 3km deep at its deepest point), South Deep Gold Mine (2.99 km deep), and the Kopanang Gold Mine (2.24km deep). Indeed, the only other mines in the top ten are in Canada and the U.S.
All mining has never been environmentally friendly—to say the least of it. However, the concentration of such activity in such close proximity also creates a perfect storm for a widespread environment disaster zone, toxic to life of the plant, animal and humankind.
There are, according to authorities, over 380 gold mines in Gauteng Province, alone, which contain elevated levels of toxic and radioactive metals including cadmium, cobalt, copper, zinc, uranium, and arsenic.
According to Campbell, when reached by High Times, the results of his study so far are not hemp specific as he was also unable to obtain a cannabis license to grow his crops on campus. So far, he has only used a different fiber plant species. However, he also said, “based on my understanding and experience with the cannabis plant, I firmly advocate for its validity and potential for use in phytoremediation strategies. I have been in contact with a team from the Vaal University of Technology who are actively conducting research using numerous cannabis varieties for phytoremediation. The team is truly pioneering this work, I hope to be involved in their work in the future.”
Hemp is known (and South African research is further confirming the same) as a “hyper accumulator” of heavy metals. Further it beats out other plants already studied for their phytoremediation potential including Indian mustard, water hyacinth, alfalfa and sunflowers.
According to the U.S. Environmental Agency, the cost of phytoremediation for removing hazardous heavy metals from soil ranges from 20-50 percent of the cost of more conventional (and expensive) methods.
So far nearly 1,000 plants have been put into soil collected from the polluted areas and all have grown normally in lab tests.
Such plants could not be consumed by either animals or people but could be used downstream as non-consumable plant fiber projects (such as plantcrete).
Regardless, the news is optimistic, and further comes at a time when the entire South African cannabis discussion is headed for high gear.