Yes the KEY is PROPER mining.

Gold mining (open-cut) involve digging, crushing,... (dust stirring processes), down to cyanide process and floating gold in mercury (toxic processes). With proper management dusts and poisons may be contained in small areas. But historical/abandoned mines litter our world, none has stopped harming our environment yet!

In AUS a nickle smelting plant is closing down leaving the plants, waste ponds and contaminants to be clean-up by government(s) -- meaning 'with taxpayers money' for many decades to come.

When costing is properly done, we would wonder why we would want gold around our necks -- as a sign of 'participants of world destruction'?