Hospital emergency rooms are hives of activity. But beneath the human-sized bustle, at hospitals like Lions Gate in North Vancouver, a much smaller army is at work keeping the facility’s many high touch surfaces clean. That army, underlying its new Advanced Ultra-clean Emergency Department, is increasingly made up of copper, a metal with antimicrobial properties known for centuries but now undergoing a renaissance of scientific interest in medicine.
“High touch surfaces are places that often get contaminated by hospital acquired infections,” says Titus Wong, Vancouver Coastal Health infection control lead, head of the Lions Gate emergency room upgrade, and a microbiologist with the University of British Columbia faculty of medicine. He explains that there are two ways to attack the issue. One is through frequent cleaning and disinfection. But an additional bridge between cleaning times is the idea that surfaces built of appropriate materials can be self-disinfecting. One promising material for that application is copper.
Copper has been used as a highly effective anti-microbial as far back as 2500 BC in ancient Egypt, explains Humberto Palza of the Department of Chemical Engineering and Biotechnology at the University of Chile in Santiago. Though its effects have been known for centuries, a scientific understanding of the mechanisms of copper’s anti-microbial superpowers are more contemporary. Research in recent decades has revealed copper’s effectiveness at killing a wide range of microorganisms including Escherichia coli, methicillin-resistant Staphylococcus aureus (MRSA), Listeria monocytogenes, influenza A virus, and Clostridium difficile, among other microbes.
So at Lions Gate, copper is being increasingly used for intravenous poles, bed rails, grab bars and other high touch surfaces like light switches — places that can become contaminated and lead to hospital acquired infections. Why does copper work so well at attacking microbes? Wong explains that copper “basically punches holes in bacteria.” More specifically, copper exerts antimicrobial action through release of ions, explains Palza. Atoms of copper release copper ions forming Cu2+. These ions “can disrupt or break the membrane of the bacteria,” going inside to interact with the bacterial DNA, says Palza, explaining that copper ions are effective at killing or preventing growth of fungi and viruses too.
Copper is not only in use in hospital settings. Teck Resources, a Canadian mining company that produces copper, recently partnered on the first project of its kind for North American mass transit. It has been conducting a pilot study with Metro Vancouver’s transit operator TransLink to test the effectiveness of copper on high-touch surfaces like grab poles, with results forthcoming.
Copper is not the only metal with anti-microbial properties. Palza notes that silver is even more powerful. However, silver is more expensive and difficult to process, making copper preferable, even though it too is more costly than metals more traditionally used in hospital settings. At Lions Gate Hospital, the next phase of the ongoing project will see the delivery of waiting room furniture with arms made from copper-injected polymer, explains Andrew Tung, Director of Special Projects with Vancouver Coastal Health. Copper surfaces can reduce the bioburden or biofilm that can develop on these surfaces, even between once or twice daily thorough cleaning. “We can make these small incremental environmental changes to reduce the ability for bacteria to grow,” says Tung, with copper constantly killing microbes in real-time.
Palza is part of a scientific team looking at creating copper nanoparticle-infused polymers, and testing their effectiveness in comparison with pure copper. Studying waiting room chairs in Chilean hospitals, his team found that pure copper reduces the bioburden of surfaces by about 85%, while plastic polymer with copper can be about 70% effective. His team continues to refine these materials and is also exploring their effectiveness to prevent biofouling in marine systems, like for salmon farming.
Other work has underlined that copper’s membrane-penetrating effects can impact not only pathogenic microbes, but benign and beneficial organisms too, with a 2018 study linking excess copper to hampered growth and development in marine kelp. Copper pollution is known to have detrimental ecosystem effects. Continued study highlights that although copper is an essential micronutrient for living organisms, its biocidal properties require careful targeted use. Nevertheless, capitalizing on copper’s microbe-killing abilities is likely to grow as the world continues to focus on preventing the spread of infectious disease.