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.
Fellow environmental scientists Salerwe Mosebi, Khayalethu Ntushelo and I researched how acid mine drainage affects urban agriculture in Soweto. Residents of the area rely on their small vegetable gardens to supplement their income and help meet their nutritional needs.
