Review of publicly available academic, industry, and NGO research as well as first-hand personal accounts of the impacts of gold mining and processing.

Summary:

• Gold has high value in human society, as it has for thousands of years

• However, gold’s natural chemistry and geology results in gold ore being widely distributed in small quantities throughout the world

• The two primary processes for extracting gold, cyanidation (for large-scale mines), and mercury amalgamation (for small-scale mines), are highly toxic to the environment

• Gold ranks as one of the worst metals in terms of environmental impact

• While (uneconomic) better alternatives exist for these chemicals, the co-presence of other toxic heavy metals with gold ore means that tailings ponds unavoidably pose environmental risk

• Even in the most regulated countries, tailings dam failures occur (often due to natural events like earthquakes and flooding)

• In addition, gold is associated with armed conflict in various parts of the world, resulting in its regulated as a conflict mineral in the US and elsewhere

• Because many of the environmental impacts (including energy) of gold are during the initial stages of mining and processing, recycling—which avoids these stages—can be highly beneficial

• Gold is already highly recycled today, but with the increasing volumes of unrecycled electronics, e-waste can become an important source of recycled gold, with PCB “ore grades” 40-800 times higher than that of mined gold ore