LettersTitanium Mining in Africa Poses Health RisksTo the editors: The Canadian mining company Tiomin Resources Inc. insists that huge titanium deposits discovered on the Kenyan coast could help turn around the depressed economy of the country by generating up to $14.2 billion in revenue, apart from employment opportunities. The economic benefit is so strong that the government of Kenya might readily grant the license for the mining to commence. Yet serious health and environmental concerns have been raised. An analysis done by a Kenyan expert, Dr. Robert Mugo, underscored the existence of uranium and thorium in the mines and their toxicity as radioactive elements.1 An assessment of the exact health consequences, however, was conspicuously missing from the analysis. As in many other instances, the human cost—something that should be at the core of any environmental impact assessment—has not been considered. Both uranium and thorium emit low-energy alpha radiation. Because alpha particles and gamma radiation emitted by uranium are relatively weak, uranium poses little health hazard outside the body. Kidney disease, however, has been observed in uranium miners and animals who ingest large quantities of uranium, and this is attributable to the element’s toxic chemical properties. When ingested, uranium increases the risk of lung, bone, leukemia, and soft tissue cancers.2 Animal studies show that uranium may affect reproduction and the developing fetus. U-238 also decays into dangerous radionuclides such as radium-226 and radon-222. Thorium dioxide is classified by the US Agency for Toxic Substances and Disease Registry (ATSDR) as a “known cancer causing agent.” Though the element poses little health hazard outside the body, studies indicate that thorium may be absorbed through the skin. Workers exposed to thorium have increased chances for developing lung disease, lung cancer, and pancreatic cancer. Thorium has also been shown to cause liver disease, blood disorders, and changes to genetic material. In laboratory studies, metal poisoning and birth defects have been observed in exposed animals.3 The fact that titanium cannot be successfully mined without large amounts of water increases the risk of exposure among miners and others. The water used during the refining process will seep into the water table. The radioactive residues in the tailings diffuse in rain water and drain into water sources. In some cases the residues are aerosolized and are recycled into the atmosphere.2 The dangers of exposure are compounded when the wind blows radioactive sand and soil into the air. The mining sites are very close to the Indian Ocean. The drainage of the water into the sea will lead to bioaccumulation of radioactive material in the fish—still another source of human exposure. There is no safe method of draining radioactive water from these coastal mines other than into the Indian Ocean. It is therefore imperative that a baseline survey of the health and environmental impact be conducted as a basis for evaluating the impact of titanium mining on the human population. The economic costs might in the end be counterbalanced—if not outweighed—by the health effects. —Paul
Saoke References
1. East African Standard. The big issue. February 5,
2001, P2. [Return to text] |