Search results
Results from the WOW.Com Content Network
The long-term toxicity of copper has not been well studied in humans, but it is infrequent in normal populations that do not have a hereditary defect in copper homeostasis. [103] There is little evidence to indicate that chronic human exposure to copper results in systemic effects other than liver injury. [82]
Smelting involves more than just melting the metal out of its ore. Most ores are the chemical compound of the metal and other elements, such as oxygen (as an oxide), sulfur (as a sulfide), or carbon and oxygen together (as a carbonate). To extract the metal, workers must make these compounds undergo a chemical reaction.
This oxidation state of copper is not very soluble in water. One billion years ago, after the great oxidation event the oxygen pressure rose sufficiently to oxidise Cu + to Cu 2+, increasing its solubility in water. As a result, the copper became much more available for living organisms.
The find in June 2010 extends the known record of copper smelting by about 800 years, and suggests that copper smelting may have been invented in separate parts of Asia and Europe at that time rather than spreading from a single source. [4] Knowledge of the use of copper was far more widespread than the metal itself.
Copper was probably the first metal mined and crafted by humans. [8] It was originally obtained as a native metal and later from the smelting of ores. Earliest estimates of the discovery of copper suggest around 9000 BC in the Middle East. It was one of the most important materials to humans throughout the Chalcolithic and Bronze Ages.
Copper toxicity (or Copperiedus) is a type of metal poisoning caused by an excess of copper in the body. Copperiedus could occur from consuming excess copper salts, but most commonly it is the result of the genetic condition Wilson's disease and Menke's disease, which are associated with mismanaged transport and storage of copper ions.
Reconstruction of Ötzi's copper axe (c. 3300 BCE). The Copper Age, also called the Eneolithic or the Chalcolithic Age, has been traditionally understood as a transitional period between the Neolithic and the Bronze Age, in which a gradual introduction of the metal (native copper) took place, while stone was still the main resource utilized.
Copper mining contributes significantly to copper emissions into fresh waters. Copper is also introduced into freshwater during metal corrosion , degradation, and abrasion of copper. Scrap copper metal is commonly recycled, but at the end of its manufacturing life cycle, it is discarded to landfills, which can leach significant copper into ...