The South African guidelines for the amount of uranium allowed in drinking water have been revised from 0.07 mg/ℓ to 0.01 mg/ℓ, owing to new findings regarding the health risks of uranium, which is associated with acid mine drainage (AMD) from derelict coal and gold mines and which runs into drinking water, says Federation for a Sustainable Environment (FSE) CEO Mariette Liefferink.

She states that a recent report by Professor Frank Winde from North-West University not only highlights the radioactive health risks caused by uranium but also the chemical toxicity of uranium.

“It is widely known that uranium in drinking water is statistically linked to high incidences of leukaemia. New findings show that uranium in drinking water has endocrine-disrupting and genotoxic properties, which cause transgenerational health- related impacts, kidney failure and chronic kidney disease,” says Liefferink.

She adds that AMD decanting from the Witwatersrand goldfields has high levels of heavy metals and uranium contamination, with the highest concentration in the West and Far West Rand goldfields.

“Communities in that area are at risk of incurring serious health problems, owing to the chemical toxicity of uranium and the long-term exposure to elevated levels of radioactivity. The Department of Mineral Resources’ airborne radiometric survey in its

‘Regional Mine Closures’ report indicates that there are high levels of radioactivity, which stem from mine tailings dumps, in the West Rand, the Far West Rand and Klerksdorp, as well as the central and eastern areas of the Witwatersrand,” she says.
Liefferink adds that densely populated areas of the Witwatersrand, such as the Johannesburg central business district (CBD), Carletonville, Randfontein and the western areas fall within the high-risk area for radioactivity.

“It was also found that large areas of the Johannesburg CBD have shown elevations in radioactivity, owing to tailings dumps that are used to dump construction material,” she notes.

The report also shows that the seepage of heavy metals and uranium is elevated in the wetlands and Witwatersrand areas, owing to the migration of the tailings from the tailings dams.

The National Nuclear Regulator’s Brenk report found that the main radioactive contamination pathway for people who live in close proximity to tailings dams is the inhalation and ingestion of contaminated dust, radon and radon gas, and as a result of the deposition of contaminated dust on crops.

“Young children are especially vulner- able to the ingestion of contaminated dust, as they crawl on the ground and put objects in their mouths. Further, if dust from tailings dams settles on crops and pastures, it enters the food chain,” Liefferink notes.

She adds that, although uranium is low in radioactivity, its geological age ensures that it remains radioactive for millions of years.

“It will continue to be a hazard for millions of years wherever it is deposited. When it decays, uranium forms radioactive products, including radium and radioactive-led isotopes, which, although short lived, contain high radioactive properties,” she says.

Liefferink notes that there are more than 1.6-million people living on top of or adjacent to uraniferous waste in South Africa.
“Many houses situated near mine dump tailings are informal houses that do not have concrete flooring and remain closed without ventilation for long periods. This increases the risk of radon gas inhalation, which causes lung cancer,” she says.

Meanwhile, Liefferink notes that she is also a member of seven multidisciplinary research groups currently conducting research to establish whether or not there is a link between AMD and gold mine waste and high levels of cancer in mining areas.

“I met with members of the World Health Organisation last month in connection with a research project related to cancer in mining areas that will start this year.”

She notes that long-term exposure to low-dose radiation manifests itself in different illnesses and conditions, including eye problems, heart disease and the suppression of the immune system.

“The most important health implications of uranium are caused by its high chemical toxicity risk, which is more worrying than its radiological risks.

“Uranium radiation consists of gamma, beta and alpha rays and can affect the skin and have various internal impacts. Chemical toxicity in uranium is a poison which acts differently from radiation and causes kidney failure, kidney disease and transgenerational impacts,” Liefferink says.

AMD Situation
Liefferink points out that in the Western basin of the Witwatersrand, AMD continued to flow uncontained and untreated into the Vaal and Limpopo river systems from 2002 to 2012.

“Since August 2012, the water has been neutralised by the removal of some of the heavy metals, but the damage has already been done,” she states, adding that receptor dams, such as the Robertson lake, in the West Rand, had AMD pumped into it for years, resulting in uranium levels that, in 2002, were 40 000 times above natural uranium levels in freshwater.

“The dam, which was previously used for recreational purposes, currently contains 16 mg/ℓ of uranium. There is no life in the dam and it has been declared a radioactive hot spot. The Lancaster dam, which flows into the Wonderfonteinspruit, which, in turn, flows into the Vaal river catchment, is another radioactive hot spot. The sediment within the Wonderfonteinspruit contains elevated levels of cobalt, copper, zinc, arsenic, cadmium and uranium, with the main contaminant being uranium,” she says.

The radioactivity levels in the soil in the dessicated Tudor dam, at the source of the Wonderfonteinspruit are between 10 000 becquerel per kilogram (Bq/kg) and 100 000 Bq/kg. The regulatory limit is 500 Bq/kg.

Liefferink points out that the Hippo dam, in the West Rand, which flows into the Krugersdorp game reserve and was neutra- lised in 2012, contained a crust of uranium-containing heavy metals.

“The two old hippo males in the dam were covered with this sludge. They are still alive; how- ever, they could not be examined, as they would have died if they had to be taken out of their natural environment to be examined. Until recently, there was no other life in the dam,” she states.

Liefferink adds that the Tweeloopiesspruit, which flows into the Crocodile river, is a highly toxic river system, owing to the amount of AMD that has seeped into the system over the years.

“Until recently, there was no life in that area, not even bird life. The heavy metal sludge, after the neutralisation process, is pumped into an unlined pit. This will just reintroduce the heavy metals into the environment – it does not make any sense,” she says.

“In Klerksdorp, there are constant radioactive and toxic spillages caused by the remining operations on private farmland, which have resulted in cattle dying. It is perplexing that no action is being taken. Action needs to be taken to contain the effects of AMD on the environment,” she concludes.