Copper

Copper is an essential micro-nutrient, needed at 1.3 milligrams per day, according to the International Copper Association. It is needed for red blood cell formation, protein metabolism, the production of RNA, enzyme activity, hair and skin color, and the health of the nerves. 
Colloidal Copper has been used as a remedy for gray hair, burns, arthritis, parasites and viral and bacterial infections. Colloidal Copper has been found helpful against multi-cellular parasites such as malaria, ring-worm, cryptosporidium, toxoplasma, and chronic bladder infections where bacteria have formed a multi-cellular biofilm.
Copper (Cu) is a heavy metal whose unbound ions are toxic. However, Colloidal Copper is not ionic but consists of clusters of atoms called nanoparticles and thus does not have the toxicity of ionic copper. Almost all of the copper in the body is present as a component of copper proteins, thereby reducing the in vivo concentration of unbound copper ions almost to zero. Genetic mechanisms control the processes by which copper is incorporated into apoproteins and those by which toxic accumulations of copper are avoided.

Health Effects:
Copper is an essential nutrient, required by the body in very small amounts. 
Almost every daily diet contains 2 to 3 mg of copper, only about half of which is absorbed. Any copper absorbed in excess of metabolic requirements is excreted through the bile, probably via hepatic lysosomes. On average, an adult has about 150 mg of copper in the body, of which about 10 to 20 mg is in the liver. The remainder is distributed ubiquitously.
People with Wilsons disease may be more sensitive than others to the effect of copper contamination and should consult their health care provider.

Copper Deficiency:
In genetically normal people, acquired, environmental, or dietary abnormalities rarely cause clinically significant copper deficiency. The only reported causes of such deficiency are kwashiorkor; persistent infantile diarrhea, usually associated with a diet limited to milk; severe malabsorption, as in sprue; total parenteral nutrition that is copper-free; and excess intake of a zinc salt as a dietary supplement. Treatment must be directed at the cause of the deficiency, usually with the addition of 2 to 5 mg of cupric ion daily.
Copper increases iron assimilation; iron and copper work together in the formation of hemoglobin and red blood cells. Anemia can be a copper deficiency symptom. Various enzyme reactions require copper. Copper influences protein metabolism and general healing, improves vitamin C oxidation and is integral in the formation of RNA. Low or high copper levels can be found in those with mental and emotional problems. Copper helps rid the body of parasites such as ring worm, taenia, and is beneficial for graying and thinning hair. Copper excess is not common because only a small percentage is assimilated, but toxicity problems can present serious disease states.

Some Symptoms of a Copper Deficiency:
Allergies, Anemia, Aneurysm, Arthritis, Dry Brittle Hair, Edema, Gulf War Syndrome, Hair Loss / Baldness, Heart Disease, Hernias, High Blood Cholesterol, Hypo and Hyper Thyroidism, Kawasaki Disease, Liver cirrhosis, Oppressed breathing, Osteoporosis, Parasites, Parkinson's Disease, Reduced Glucose Tolerance, Ruptured Disc, Skin Eruptions or Sores, Varicose Veins, White or Gray Hair, and Wrinkled skin.

What Happens to Copper When it is Released to the Environment?
All water is corrosive toward copper to some degree, even water termed noncorrosive or water treated to make it less corrosive. Corrosivity toward copper is greatest in very acidic water. Many of the other factors that affect the corrosivity of water toward lead can also be expected to affect the corrosion of copper.

How Will Copper be Detected in and Removed from my Drinking Water?
The regulation for copper became effective in 1992. Between 1993 and 1995, EPA required your water supplier to collect water samples from household taps twice a year and analyze them to find out if copper is present above 1.3 ppm in more than 10 percent of all homes tested. If it is present above this level, the system must continue to monitor this contaminant twice a year.  If contaminant levels are found to be consistently above the Action level, your water supplier must take steps to reduce the amount of copper so that it is consistently below that level.

Links:
References on Benefits and Toxicity of Copper and Zinc

Copper Applications in Health & Environment

International Copper Association

A Common Parasite Reveals Its Strongest Asset: Stealth; Toxoplasma