The Benchmark Institute Report

Written by  Friday, 25 July 2008 04:28
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The persistent activism of Mariette Liefferink, the C.E.O. of the Federation for a Sustainable Environment has kept the media attention on the impact of uranium and gold mining on the Wonderfonteinspruit catchment area for a number of years.

The Nuclear [Nuclear Regulator] of South Africa finally admitted publicly in February 2008 (Tempelhoff, 2008) that radioactive toxins from mine waste facilities on the West Rand have so badly polluted soil and water in the area stretching from Randfontein almost to Potchefstroom that food grown in the area would be dangerous for both human and animal consumption (Temelhoff, 2008).

Liefferink found the following:

The Water Research Report, No 1214, entitled "An Assessment of sources, pathways, mechanisms and risks of current and potential future pollution of water and sediments in gold-mining areas of the Wonderfonteinspruit Catchment" on page 152 states:

"9.7.3

Health effects by route of exposure Inhalation exposure

The health effects of uranium particles inhaled seem to depend on two factors - the size of the particles and the water-solubility of the particles.

Small particles (< 2micron in diameter) are carried by the inhaled air stream all the way into alveoli (the deep respiratory tract). Here the particles can remain for periods from weeks up to years (ICRP, 1994, NCRP, 1997), depending on their solubility. Highly insoluble uranium compounds may remain in the alveoli, whereas soluble uranium compounds may dissolve and pass across the alveolar membranes into the bloodstream, where they may exert systemic toxic effects. In some cases insoluble particles are absorbed into the body from the alveoli by phagocytosis into the associated lymph nodes.

Larger particles, being more susceptible to gravitational forces, tend to deposit higher in the respiratory tract. They are cleared from the respiratory tract by the formation of mucous, which is swept up into the mouth, and expurgated or swallowed into the gastrointestinal system. The latter fate of the particles is converted from the pulmonary system to the gastrointestinal system. The gastrointestinal system is more chemically aggressive than the pulmonary system, and uranium compounds that would not dissolve in the lungs may become systemically available due to chemical dissolution in the gut. Acute pulmonary effects have, however, been ascribed to chemical toxicity as opposed to radiotoxicity of uranium in observations of experiments with rabbits. However, insoluble particles may reside in the lungs for years causing chronic radiotoxicity to be expressed in the alveoli."

In terms of the National Nuclear Regulator's Report No TR-RRD-07-0006, entitled "Radiological Impacts of the Mining Activities to the Pubic in the Wonderfonteinspruit Catchment Area" it was found:

Page 40 (S 5.1.1)

"It has to be mentioned that the near-surface atmospheric air presents commonly the third relevant medium at mining sites, because emissions of radon and/or contaminated dust may

cause elevated radiation exposures of the public by inhalation and/or contributions to food chain pathways. Such exposures are likely to occur in the vicinity of the slimes dams located in the Wonderfonteinspruit catchment area but they are not part of the present project."

Page 42 (S 5.1.3)

"The uptake of sediments during cattle watering at banks of dams, ponds, furrows, etc. is an important pathway, which can cause contributions to the effective doses that are some orders of magnitude above the contributions stemming from pure water uptake by cattle.

"During the stay on contaminated sites, unintended ingestion of soil (small soil particles with diameter less than 0.5 mm) presents a realistic exposure pathway, which especially for "playing kids" can cause contributions to the effective doses in the same order as the external gamma radiation."

P 57 (S 5.2.3.4)

"The scenario comprises four exposure pathways. The pathways p = WaPaCa and p = WaSoCa concern the uptake of radionuclides with cattle fodder (pasture grass, clover and other forage plants) and the direct uptake of contaminated soil during grazing, respectively. The use of radioactively contaminated water for the irrigation of pasture land contaminates the upper soil layer. This contributes to the pathWaPaCa via the radionuclide transfer from soil to plant, and determines the exposure pathway WaSoCa. Additionally, the exposure pathway WaPaCa takes into account the interception of activity by forage vegetation leafs during irrigation."

"...Similarly, the exposure pathway p = WaPaPo comprises direct pasture contamination (activity interception by leafs of forage vegetation during irrigation) and indirect pasture contamination due to the previous contamination of the root zone of soil."

P 89 (S 6.1)

"However, in total it seems that - apart from the transfer factor problem - the dose calculations presented in this report draw a picture of the radiological situation in the WCA that is not too far from reality. Even the assessment of the incident site MP38 (Bridge, Carletonville) indicates a serious long term problem concerning the transport of slimes into the environment (runoff water erosion from the very steep slopes of the slimes dams located throughout the WCA)."

In terms of the Water Research Commission Report 1214/1/06 entitled : "An Assessment of Sources, Pathways, Mechanisms and Risks of Current and Potential Future Pollution of Water and Sediments in Gold-Mining Areas of the Wonderfonteinspruit Catchment" it was found:

P 154 (S 9.7.4)

"Death

...Animals exposed to uranium compounds by the inhalation route have died, the cause of death being traced to damage to the renal system.”

P 119 (S 9.1.2)

"Risk assessment

Exposure assessment

Principal modes of contact are ingestion of water and food products, and inhalation of dust and aerosols."

"Plant and animal uptake of uranium

Uranium mobility may also be increased owing to the formation of soluble complexes with chelating agents produced by micro-organisms in the soil Uranium may be transported to vegetation by air or by water. It can be deposited on the plants themselves by direct deposition or resuspension, or it can adhere to the outer membrane of the plant's root system, with potential limited absorption. Similarly uranium deposited on aquatic plants or water may be adsorbed or taken up from the water.

The plants, aquatic or terrestrial, may be eaten directly by humans or consumed by land or aquatic animals which provide food for humans. The uptake or bioconcentration of uranium by plants or animals is the mechanism by which uranium in soil, air, and water enters into the food chain of humans...Because of the higher root sorption of uranium, consumption of radishes and other root vegetables grown in uranium-containing soils may be a source of human exposure."

Systemic effects (ATSDR, 1999)

Respiratory effects: Prolonged exposure to high levels of insoluble uranium dust may damage the lungs by chemical action

Renal effects: Uranium is nephrotoxic, exerting its toxic effect by chemical action mostly in the proximal renal tubules in humans and animals.

P 156 (9.7.4)

"...laboratory experiments have revealed that, where there are very high concentrations of uranium in tissues (including bone) prolonged action of the uranium on cells exerts a definite carcinogenic effect.

"...in other words, there is no safe limit for carcinogens."

In terms of ss 13.6.7 of the State of the Environment Report 2002, North West Province, it is found:

"Wind blown dust from mine rock and sand dumps and slimes dams could pose a health hazard due to inhalation of uranium contaminated dust particles. Also radionuclide-contaminated dust can be dispersed far distances from the source, affecting agricultural lands for fruit and crop plantations."

(Similar fact evidence can be found in the effects of the Chernobyl nuclear disaster in 1986. The clouds of radiation contaminated particles which drifted over Scandinavia resulted in elevated cancer levels in these countries, as well as the need to slaughter thousands of cattle because of elevated radiation levels in their milk.)

"If uranium is inhaled or ingested, it poses increased risks of lung cancer and bone cancer. By its insidious nature the effect of radioactive exposure of the general population, cancer may take anything up to 40 years to manifest itself. Where the effect is genetic, anomalies may take generations to appear."

Bone is the principal storage site in the body, and the rest is distributed to other organs and tissues.

Uranium deposited in the bones and other organs is subsequently released back to the blood stream with at least two different half lives. Similar to other heavy metals causing neurotoxic problems, uranium can cross the blood-brain barrier. Of particular concern to women are studies with laboratory animals which found uranium in the placenta, foetus, and milk of females and in the tissues and urine of offspring fed milk from exposed females.

"Mutagenic effects of radiation occur in the form of genetic mutations passed on to subsequent generations and do not necessarily depend on a dose threshold (stochastic effects)" ss 13.6.7

And

"Number of cancer cases reported in a potentially contaminated area directly attributed to the chronic effects of radioactivity e.g. pancreatic cancer." ss 13/6/11 Ibid.

"There is a growing body of evidence pointing that both the long- and short-term effects substances present in the environment may be impacting on the health of the population, particularly in the gold mining areas."

"Gold mine dumps need to be rehabilitated and revegetated where possible to mitigate the effects of wind-blown radioactive dust contamination of surrounding urban and rural areas." Ibid.