The rise and fall of mercury: Converting a resource to refuse after 500 years of mining and pollution

The link of mercury (Hg) pollution to Hg mining is rarely made, although Hg primary production presently is as large as global Hg emissions from coal combustion. Here we present historical comparisons on global, continental and national scales, covering up to five centuries of Hg production and consumption. Nearly half of the historical consumption has been pre-industrial, notably for silver and gold mining by amalgamation. More than half has been mined in Europe and one quarter in the Americas. Four economic periods with different control of global Hg price and production were discerned. The Hg price rose sharply after 1830 when Spain no longer controlled the Hg market and when consumption started to shift to gold mining in North America and later on industrial uses. In the 1970's, however, the price as well as quantities consumed plunged as a result of rising health and environmental concerns. In Sweden, per-capita consumption has recently dropped below pre-industrial levels, exemplifying a successful implementation of environmental policy. The chlor-alkali industry is still the globally dominating Hg consumer, and large stocks to be decommissioned in industrialized countries need political guidance to avoid transfer of Hg and related risks to other countries, a potential transfer to small-scale miners favoured by low Hg prices.