More than 200 mounds of earth contaminated with heavy metals, notably uranium, lie within sight of South Africa's commercial capital, according to the Harvard International Human Rights Clinic.
Tens of thousands of poor South Africans in Johannesburg spend their lives in the shadow of vast mine dumps, exposing them to toxic substances such as arsenic, lead and uranium.
The gold rush from 1886 that caused the imposing slag heaps to spring up around South Africa's largest city saw many investors and miners become fabulously wealthy.
The same was not true of those who lived and worked near the pits, and were exposed to dangerous cocktails of dust and chemicals.
TRT World's Kim Vinnell reports.