|Classification and external resources|
A Kayser-Fleischer ring, copper deposits found in the cornea, is an indication the body is not metabolizing copper properly.
Copperiedus refers to the consequences of an excess of copper in the body. Copperiedus can occur from eating acid foods cooked in uncoated copper cookware, or from exposure to excess copper in drinking water or other environmental sources.
Copper in the blood exists in two forms: bound to ceruloplasmin (85–95%), and the rest "free", loosely bound to albumin and small molecules. Free copper causes toxicity, as it generates reactive oxygen species such as superoxide, hydrogen peroxide, and the hydroxyl radical. These damage proteins, lipids and DNA.
Symptoms and presentation
Acute symptoms of copper poisoning by ingestion include vomiting, hematemesis (vomiting of blood), hypotension (low blood pressure), melena (black "tarry" feces), coma, jaundice (yellowish pigmentation of the skin), and gastrointestinal distress. Individuals with glucose-6-phosphate deficiency may be at increased risk of hematologic effects of copper. Hemolytic anemia resulting from the treatment of burns with copper compounds is infrequent.
Chronic (long-term) effects of copper exposure can damage the liver and kidneys. Mammals have efficient mechanisms to regulate copper stores such that they are generally protected from excess dietary copper levels.
The U.S. Environmental Protection Agency's Maximum Contaminant Level (MCL) in drinking water is 1.3 milligrams per liter. The MCL for copper is based on the expectation that a lifetime of consuming copper in water at this level is without adverse effect (gastrointestinal). The USEPA lists evidence that copper causes testicular cancer as "most adequate" according to the latest research at Sanford-Burnham Medical Research Institute. The Occupational Safety and Health Administration (OSHA) has set a limit of 0.1 mg/m3 for copper fumes (vapor generated from heating copper) and 1 mg/m3 for copper dusts (fine metallic copper particles) and mists (aerosol of soluble copper) in workroom air during an eight-hour work shift, 40-hour work week.
EPA cancer data
The EPA lists no evidence for human cancer incidence connected with copper, and lists animal evidence linking copper to cancer as "inadequate". Two studies in mice have shown no increased incidence of cancer. One of these used regular injections of copper compounds, including cupric oxide. One study of two strains of mice fed copper compounds found a varying increased incidence of reticulum cell sarcoma in males of one strain, but not the other (there was a slightly increased incidence in females of both strains). These results have not been repeated.
In cases of suspected copper poisoning, penicillamine is the drug of choice, and dimercaprol, a heavy metal chelating agent, is often administered. Vinegar is not recommended to be given, as it assists in solubilizing insoluble copper salts. The inflammatory symptoms are to be treated on general principles, as are the nervous ones.
When acidic foods are cooked in unlined copper cookware, or in lined cookware where the lining has worn through, toxic amounts of copper can leach into the foods being cooked. This effect is exacerbated if the copper has corroded, creating reactive salts. Actual cooking may not be required for copper to leach into acidic liquids if they are stored in copper for a period of time. Many countries and states prohibit or restrict the sale of unlined copper cookware.
Copper oxide glaze on cups used for hot liquid might also be a concern, as well as copper pipes for conveying water to the home.
OSHA has set safety standards for grinding and sharpening copper and copper alloy tools, which are often used in nonsparking applications. These standards are recorded in the Code of Federal Regulations 29 CFR 1910.134 and 1910.1000.
With an LD50 of 30 mg/kg in rats, "gram quantities" of copper sulfate are potentially lethal in humans. The suggested safe level of copper in drinking water for humans varies depending on the source, but tends to be pegged at 2.0 mg/l.
A significant portion of the toxicity of copper comes from its ability to accept and donate single electrons as it changes oxidation state. This catalyzes the production of very reactive radical ions, such as hydroxyl radical in a manner similar to Fenton chemistry. This catalytic activity of copper is used by the enzymes with which it is associated, thus is only toxic when unsequestered and unmediated. This increase in unmediated reactive radicals is generally termed oxidative stress, and is an active area of research in a variety of diseases where copper may play an important but more subtle role than in acute toxicity.
Some of the effects of aging may be associated with excess copper. In addition, studies have found that people with mental illnesses, such as schizophrenia, had heightened levels of copper in their systems. However, it is unknown at this stage whether the copper contributes to the mental illness, whether the body attempts to store more copper in response to the illness, or whether the high levels of copper are the result of the mental illness.
Indian childhood cirrhosis
One manifestation of copper toxicity, cirrhosis of the liver in children (Indian childhood cirrhosis), has been linked to boiling milk in copper cookware. The Merck Manual states recent studies suggest that a genetic defect is associated with this particular cirrhosis.
Elevated free copper levels exist in Alzheimer's disease. Copper and zinc are known to bind to amyloid beta proteins in Alzheimer's disease. This bound form is thought to mediate the production of reactive oxygen species in the brain.
Too much copper in water may damage marine and freshwater organisms such as fish and molluscs. Fish species vary in their sensitivity to copper, with the LD50 for 96-h exposure to copper sulphate reported to be in the order of 58 mg per litre for Tilapia (Oreochromis niloticus) and 70 mg per litre for catfish (Clarias gariepinus)  The chronic effect of sublethal concentrations of copper on fish and other creatures is damage to gills, liver, kidneys and the nervous system. It also interferes with the sense of smell in fish, thus preventing them from choosing good mates or finding their way to mating areas.
Copper and copper alloys such as brass have been found to be toxic to bacteria via the oligodynamic effect. The exact mechanism of action is unknown, but common to other heavy metals. Viruses are less susceptible to this effect than bacteria. Associated applications include the use of brass doorknobs in hospitals, which have been found to self-disinfect after eight hours, and mineral sanitizers, in which copper can act as an algicide. Overuse of copper sulfate as an algicide has been speculated to have caused a copper poisoning epidemic on Great Palm Island in 1979.
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