Copper is not very toxic in comparison to other metals and early humans used too little of it to begin concentrating it in soil, air, or water to the extent that it would affect human health or ecosystems.
Gold is believed to have been used earlier than copper, though its softness and scarcity made it impractical for widespread use, whereas copper is harder and found in pure form (native copper) in many parts of the world.
(Gold and copper's distinct colors and existence in pure form made it easy for our early ancestors to distinguish the two metals from other minerals and stones they came across.) There is disagreement among archaeologists about the exact date and location of the first utilization of copper by humans.
Archaeological evidence suggests that copper was first used between 8,000 and 5,000 B.
C., most likely in the regions known now as Turkey, Iran, Iraq and toward the end of that period the Indian subcontinent.
Between seven and ten thousand years ago, our early ancestors discovered that copper is malleable, holds a sharp edge, and could be fashioned into tools, ornaments, and weapons more easily than stone, a discovery that would change humanity forever.
This meeting of humans and metals would be the first step out of the Stone Age and into the ages of metals: the Bronze and Iron Ages.
Thus began the increased movement of elements and minerals out of their parent geological formations and into the air, soil, water, and living organisms by way of smelters, furnaces and mine tailings.
The first several thousand years of copper production contributed little to global or even local pollution.
Archeologists have also found evidence of mining and annealing of the abundant native copper in the Upper Peninsula of Michigan in the United States dating back to 5,000 B. Native copper was likely used first, as it did not require any process to purify it.