The use of cyanide in the mining process of metals such as gold and silver, leads to severe environmental risks. The use of cyanide in gold mining has led to environmental disasters in many countries across the world such as the United States, Canada, China, Guyana, Bolivia, Zimbabwe, Philippines and Ghana. Recently, Community groups and NGOs in Europe and the United States issued a report which exposed the danger of unregulated cyanide compound releases from mines around the world.
Cyanide is deadly for human beings as well as the environment. The main risks associated with the use of cyanide in mining process are exposure of workers to concentrated hydrogen cyanide gas, leaking of cyanide into the environment and exposure of surrounding communities to cyanide due to accidental releases. During the mining process, the release of cyanide along with other toxic chemicals such as arsenic, lead, cadmium and mercury, leads to harmful effects and permanent damage to some species of animals, plants and human beings. It may also result in deforestation, soil erosion, land slides, and contamination of underground water.
The release of arsenic and other poisonous chemicals during the cyanide leaching process is very dangerous. The cyanide-leach wastes of mining process have the potential to negatively impact municipal sewage and water treatment procedures. It also potentially increases the human intake of several toxic substances. All the cyanide-containing water bodies formed during gold mining milling operations are hazardous to wild animals and migratory birds such waterfowl and bats, if not managed properly. Even accidental leaking of cyanide solutions into rivers and streams will kill fish and other aquatic animals massively. Especially, freshwater fish are the most cyanide-sensitive aquatic organisms.
Workers at gold mining operations can be exposed to cyanide during the heap leaching or tank extraction process. Cyanide is very harmful to human being as it acts as a poison to the human body. Severe breathing difficulties develop when cyanide is inhaled, swallowed or absorbed through the skin. Cyanide blocks the absorption of oxygen by cells, making the victim to suffocate. Exposure to concentrated levels of cyanide can be fatal to the human beings. Exposure to very low concentration of cyanide may cause cancer in people or animals.
We are not certain about the presence and concentration of numerous cyanide compounds in mining wastes. We are also not sure about the presence, persistence, and toxicity of cyanide and related compounds in the environment. But as the effects of cyanide are getting more obvious, the opposition to cyanide leaching in gold mining is also increasing.
The use of cyanide in mining causes an unreasonable risk to the health of people, wildlife, and fish. As the hazards of cyanide in mining process are very much obvious, it is the responsibility of the Government and mining companies to take essential steps. The International Cyanide Management Code provides direction and guidance on how to manage cyanide to ensure protection of workers, the environment and the communities adjacent to mining operations. Mining waste should be regulated in the same manner as other chemical or industrial waste. The public needs enough awareness about mining hazards. The government should ban mining projects that result in environmental hazards in order to prevent ecological disasters. Citizens must also oppose such mining projects. Many organizations in countries such as United States, Canada and Turkey have started associations for banning cyanide leaching in mining.