Copper has a long history of use for disinfection and treating infections, dating back to ancient civilizations. As early as 2600 B.C., ancient Egyptians used copper for sterilizing wounds and drinking water. In Egyptian hieroglyphics, copper was denoted by the ankh symbol, representing endless life. One of the oldest known medical records, the Smith Papyrus, attributed to an Egyptian physician around 1700 B.C. but based on information dating back to 3200 B.C., documents the use of copper as an anti-infection agent.
The Chinese used copper coins as medicine to cure bladder problems and aches as early as 1600 B.C. Hindus have been storing holy water from the Ganges River (Gangajal) in copper utensils for centuries before drinking it. The water remained clean due to copper’s anti-fouling and bactericidal properties, protecting them from diarrhea. The ancient Greeks during the time of Hippocrates (400 B.C.) independently discovered the sanitizing power of copper. They used copper to treat pulmonary diseases and to purify drinking water. Early Phoenician sailors treated their battle wounds with shavings from their bronze swords and placed copper strips in their ships’ hulls to inhibit fouling. The Romans used copper for treating eye infections and cleaning wounds.
During the Middle Ages, copper was used less prominently in Europe due to a decline in medical knowledge. However, it continued to be used in other parts of the world, such as in traditional Chinese and Indian (Ayurvedic) medicine. During the Renaissance, with the revival of scientific inquiry, copper’s medicinal properties were rediscovered. Alchemists and early chemists experimented with copper compounds for treating diseases and infections. Copper sulfate was used to treat agricultural diseases and as an antiseptic in medical treatments. The advent of antibiotics reduced the reliance on copper for medical purposes. However, it remained in use in various forms, such as copper-based fungicides in agriculture and copper-lined vessels for water purification. In recent decades, the rise of antibiotic-resistant bacteria has renewed interest in copper as an antimicrobial agent.
Early civilizations did not understand the mechanisms by which copper had such a beneficial effect on their lives. Today, with the development of modern microbiology, the potent antimicrobial properties of copper have been scientifically validated and the biocidal mechanisms elucidated (Borkow, G. (2012) Using copper to fight microorganisms. Current Chemical Biology 6(2): 93-103.). Heavy metals, including gold and silver, also possess antibacterial properties, but copper’s specific atomic configuration, featuring a free electron in its outer orbital shell that readily participates in oxidation-reduction reactions, makes copper an extremely reactive and highly effective biocide. Copper ions disrupt microbial cell membranes, generate reactive oxygen species, and interfere with vital enzymes, leading to the death of bacteria, viruses, and fungi. Importantly, copper’s antimicrobial effect is not reduced over time. For example, the old railings of the Grand Central Terminal in New York remain highly biocidal even though they were installed more than a hundred years ago, demonstrating that the antimicrobial properties of copper do not diminish over time (https://www.smithsonianmag.com/science-nature/copper-virus-kill-180974655/).
Today, copper surfaces and copper impregnated products are used in hospitals to reduce the spread of infections (Borkow, G. and Monk, A.B. (2012) Fighting nosocomial infections with biocidal non-intrusive hard and soft surfaces. World Journal of Clinical Infectious Diseases 2(4): 77-90; Marcus et al (2017) Reduction of healthcare-associated infection indicators by copper oxide impregnated textiles: crossover, double-blind controlled study in chronic ventilator-dependent patients. American Journal of Infection Control 45(4): 401–403); and to heal wounds (e.g. Melamed et al. (2021) Stimulation of Healing of Non-Infected Stagnated Diabetic Wounds by Copper Oxide-Impregnated Wound Dressings. Medicina 57(10):1129).
