It was used in the aftermath of the Chernobyl nuclear disaster in the 1990s. Ongoing research in South Africa suggests that hemp may be able to clean up some of the most devastated areas on earth, namely mines South African gold.
In a landmark study, funded by the University of the Witwatersrand in South Africa, graduate student Tiago Campbell, MSc candidate in environmental science, studies phytoremediation as a possible way to regenerate over 400 kilometers of land in Gauteng, l ‘Free State and Northwestern provinces.
It is a region of the planet known for several things. It is one of the richest gold deposits in the world (and this since its discovery). Mining began in South Africa in 1852 (copper, not gold), but the rush has hardly abated since then. In the 1860s, two of the largest diamonds in the world, including the 83-carat South African star (aka the Cullinan I Diamond which is in the Queen of England’s Golden Scepter) and the 21-karat Eureka Diamond were unearthed, which, as you might expect, sparked a rush of precious metals and precious stones in the country.
Unsurprisingly, it’s also a place where many of the top 10 the deepest mines in the world are located including the deepest in the world, the Mponeng gold mine, which extends as far as 4.27 km (just over two miles) underground, the second deepest mine, the Driefontein mine (3, 42 km deep), the third deepest mine (Kusasalethu Gold Mine), 3.38 km deep, the Moab Khotsong gold mine, the fourth deepest in the world (just over 3 km deep at its deepest point), the South Deep Gold Mine (2.99 km deep) and the Kopanang Gold Mine (2.24 km deep). Indeed, the only other mines among the top ten are in Canada and the United States.
All mining has never been environmentally friendly, to say the least. However, the concentration of such activity in such proximity also creates a perfect storm for an area of widespread ecological disaster, toxic to the life of plants, animals and mankind.
There are, according to authorities, more than 380 gold mines in Gauteng province alone, which contain high levels of toxic and radioactive metals, including cadmium, cobalt, copper, zinc, uranium and arsenic.
How hemp can help South Africa
According to Campbell, when reached by Highlights, the results of his study so far are not specific to hemp as he was also unable to obtain a cannabis license to grow his crops on campus. So far he has only used another species of fiber plant. However, he also said, “Based on my understanding and experience with the cannabis plant, I strongly advocate its validity and potential for use in phytoremediation strategies. I have been in contact with a team from Vaal University of Technology who are actively conducting research using many varieties of cannabis for phytoremediation. The team are really pioneers in this work, I hope to be involved in their work in the future.
Hemp is known (and South African research further confirms it) as a “hyper accumulator” of heavy metals. In addition, it beats other plants already studied for their phytoremediation potential, including mustard, water hyacinth, alfalfa and sunflower.
According to the United States Environmental Agency, the cost of phytoremediation to remove dangerous heavy metals from soil ranges from 20 to 50 percent of the cost of more conventional (and expensive) methods.
So far, nearly 1,000 plants have been placed in the soil collected from the polluted areas and all have grown normally in laboratory tests.
These plants could not be consumed by animals or humans, but could be used downstream as non-consumable plant fiber projects (such as plant concrete).
Either way, the news is upbeat and furthermore comes at a time when the whole South African cannabis discussion is moving into high gear.