Hemp Is Being Used To Clean Toxic Mining Residues In South Africa

In recent news, hemp has been found to absorb toxic materials in soil that’s heavily contaminated, and a South African researcher is looking to put that into action. He wants to test the potential of hemp farming to cleanse the soil in polluted former gold mining areas while testing how hemp farming could enhance economic development in abandoned regions.

The man behind the mission is Tiago Campbell, a master’s degree candidate in environmental science at the University of the Witwatersrand. Campbell is currently evaluating the potential for rejuvenation lands near Johannesburg in Gauteng that have been contaminated for more than 130 years due to reckless mining practices.

Campbell will do these evaluations within the Witwatersrand Basin, one of the world’s most extensive gold deposits running for 400 kilometers. Within the Gauteng Province, HempToday reports that South Africa’s Federation for a Sustainable Environment says there are at least 380 abandoned mining areas, all of which contain “elevated levels of toxic and radioactive metals” like arsenic, cadmium, cobalt, copper, zinc, and uranium.

Campbell then added that harvested hemp containing pollutants could not be used for human consumption or within food, but it’s the perfect raw material for other products like bioplastics, textiles, and construction materials.

Italian researchers gave a prime example. In a different report, HempToday noted that these researchers suggested that hemp hurd used to clean soil of heavy metals is safe for building materials like hempcrete and biomass from phytoremediation attempts is a reliable source of energy.

Campbell added that cleaning up the soils of contaminated lands could also allow these unpopulated areas to see life again. Thus far, his research has confirmed that hemp is a “heavy metal hyper-accumulator” that’s beat other plants studied for phytoremediation potential (soil cleansing). Other plants studied were Indian mustard, water hyacinth, alfalfa, and sunflower.

Debut evidence that hemp was a hyper-accumulator began to emerge back in the 90s when Ukraine’s Institute of Bast Crops noted hemp’s ability to absorb the dangerous heavy metals left over from the Chernobyl nuclear zone that left soil drenched in lead, nickel, cadmium, zinc, and chromium.

The U.S. Environmental Protection Agency estimates that the cost of phytoremediation to remove dangerous heavy metals from soil is roughly 20-50% of what “conventional” methods would cost, which uses physical, chemical, or thermal technology. The University of Witwatersrand is funding Campbell’s latest project and is excited to be a part of the future of hemp.