The bustling City of Johannesburg ("Joburg") did not exist 130 years ago. Then gold was discovered on a farm in the area, leading to a gold rush, a tent city, and intensive gold mining in the Witwatersrand region of South Africa.
As it happens, the gold ore is also rich in uranium. At many mine sites, uranium is separated out as a byproduct after gold is extracted from the ore. In this way South Africa has become a small but significant uranium producer (about one percent of world production). Meanwhile, mountains of gold-mine tailings continue to pile up everywhere. These sand-like mining wastes are quite radioactive and will remain so for hundreds of millennia.
The tailings contain some of the deadliest naturally-occurring radionuclides known to science. Radium and polonium, uranium and thorium, along with radioactive isotopes of lead and bismuth abound. Radon gas is given off in great quantities, created by the spontaneous disintegration of radium atoms. When the sandy material is used in construction, as it often is, the resulting buildings experience a build-up of radon gas inside. Radon is the leading cause of lung cancer among non-smokers. The U.S. Environmental Protection Agency estimates that 20 to 30 thousand Americans die every year from lung cancer caused by breathing radon gas at home.
At the recent "Nuclearisation of Africa" conference in Joburg (November 16−19) I was informed that the radioactive tailings in South Africa are four times greater in volume than the uranium tailings in all other countries combined. Traveling around the region it is easy to appreciate this fact. Countless colossal mounds of uncovered tailings are everywhere to be seen, even within Joburg itself. They are enormous in size, and are often located right beside built-up areas. In some case villages of tin-roofed shacks are perched right on top of the radioactive sand-like materials. Wind carries the yellow dust everywhere, slowed only by irregular patches of vegetation that serve as anchors. Once pristine rivers have become polluted and dewatered with little or no remediation in sight.
Geologists who have worked at mines in the area are often unaware of the radioactive legacy their companies are leaving behind for future generations. A great deal of ignorance prevails.
The four-day "Nuclearisation of Africa" conference was organized by the IPPNW (International Physicians for the Prevention of Nuclear War), AUA (African Uranium Alliance), and FSE (Federation for Sustainable Development). The main objective was to assist participants from South Africa, Niger, Congo, Tanzania, Namibia and Zambia, to understand and avoid the radioactive legacy of uranium mining, and to prevent the even greater radioactive legacy left behind by nuclear power plants in the form of high-level radioactive waste (irradiated nuclear fuel).
Africa has an abundance of renewable resources and is perfectly positioned to take advantage of the current world-wide trend away from nuclear technology towards genuinely sustainable alternatives. Those alternatives were also highlighted during the four-day conference.