Effects On The Environment
Despite being used in 90% of gold production, gold cyanidation is controversial due to the toxic nature of cyanide. Although aqueous solutions of cyanide degrade rapidly in sunlight, the less-toxic products, such as cyanates and thiocyanates, may persist for some years. The famous disasters have killed few people — humans can be warned not to drink or go near polluted water — but cyanide spills can have a devastating effect on rivers, sometimes killing everything for several miles downstream. However, the cyanide is soon washed out of river systems and, as long as organisms can migrate from unpolluted areas upstream, affected areas can soon be repopulated. In the Someș river below Baia Mare, the plankton returned to 60% of normal within 16 days of the spill. Famous cyanide spills include :
| Year | Mine | Country | Incident |
|---|---|---|---|
| 1985-91 | Summitville | US | Leakage from leach pad |
| 1980s-present | Ok Tedi | Papua New Guinea | Unrestrained waste discharge |
| 1995 | Omai | Guyana | Collapse of tailings dam |
| 1998 | Kumtor | Kyrgyzstan | Truck drove over bridge |
| 2000 | Baia Mare | Romania | Collapse of tailings dam (see 2000 Baia Mare cyanide spill) |
| 2000 | Tolukuma | Papua New Guinea | Helicopter dropped crate into rainforest |
Such spills have prompted fierce protests at new mines that involve use of cyanide, such as Roşia Montană in Romania, Lake Cowal in Australia, Pascua Lama in Chile, and Bukit Koman in Malaysia.
Read more about this topic: Gold Cyanidation
Famous quotes containing the words effects and/or environment:
“Consider what effects which might conceivably have practical bearings we conceive the object of our conception to have. Then our conception of these effects is the whole of our conception of the object.”
—Charles Sanders Peirce (1839–1914)
“A positive learning climate in a school for young children is a composite of many things. It is an attitude that respects children. It is a place where children receive guidance and encouragement from the responsible adults around them. It is an environment where children can experiment and try out new ideas without fear of failure. It is an atmosphere that builds children’s self-confidence so they dare to take risks. It is an environment that nurtures a love of learning.”
—Carol B. Hillman (20th century)