‘Gold mine pollution is poisoning Soweto’s water and soil – study finds food gardens are at risk’ 23 May 2024

For 140 years, gold mines in Johannesburg, South Africa have been leaking wastewater contaminated with heavy metals. The acid mine drainage from Johannesburg’s estimated 278 abandoned mines and 200 mine dumps includes uranium (a radioactive metal), toxic arsenic, copper, cobalt, nickel, lead and zinc. Acid mine drainage can pollute land and water sources up to 20 kilometres away from a mine unless it is remediated by mining companies. The contamination cascades through food webs and poisons river water, plants and animals. Before 1994 in South Africa, African communities were forcibly relocated to places near mine dumps in Soweto, south-west of Johannesburg. Today, Soweto is home to 1.9 million people who are exposed to acid mine drainage.

…Our research found that acid mine drainage has contaminated the streams, irrigation water sources and subsequently, the soil on the land adjacent to the Klip River, which flows south and west of Soweto. In very mild doses, exposure to the heavy metals in acid mine drainage can cause dehydration and abdominal pain. In cases of serious exposure, birth defects, brain damage, cancer and miscarriages can result. Mining companies are supposed to keep money aside to rehabilitate the environment after they close and can only close down once government has granted a closure certificate. But this did not always happen in the past. The authorities, both government and mining companies, should appreciate the seriousness of the situation so that they can do something about it. Strategies could include chemical treatment of the water and construction of wetlands along the rivers. Wetland plants can soak up large quantities of contaminants, such as heavy metals.

…People who live along the Klip River are also at risk of being exposed to heavy metals. We also found that the rest of Soweto’s residents are very vulnerable to heavy metal dust that is blown around during strong winds. We hope the government will take steps to safeguard people in Soweto affected by acid mine drainage. This will help ease the burden on an already strained public health sector now and in the future. The abandoned mines should be lawfully decommissioned. People living very close to the mine dumps must be relocated, and a rehabilitation programme must be implemented to sustain urban agriculture.