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The Coronavirus Is Everywhere - So Why Isn’t Copper?

July 21, 2020

 

In the age of the coronavirus, why isn’t every hospital or restaurant surface covered with copper? From doorknobs, to toilets, to emergency rooms, to food preparation surfaces in every kitchen in hospitals, restaurants, etc.

During the start of the pandemic we would see a new study every few weeks showing how the virus spreads and how long it can live on different surfaces.


Copper clad surfaces in an intensive care unit are shown circled. Copper cladding was found to reduce
 healthcare-associated infections by 58 percent in one study. (Image: Medical University of South Carolina.)

How Does Copper Kill Microbes?


A: Copper dissolves from the copper surface and causes cell damage
B: The cell membrane ruptures because of copper and other stress phenomena 
C: Copper ions induce the generation of reactive oxygen species, which cause further cell damage
D: Genomic and plasmid DNA becomes degraded
Image: American Society of Microbiology

 

So, why don’t we see more copper used in public surfaces?

Here are some reasons why the use of copper hasn’t been implemented as widely as scientists would like to see:

 

1. The Center for Disease Control has not definitively declared that COVID-19 can spread from contact with contaminated surfaces
Even after several dozens of studies around the world showing similar results to the following table:

TABLE 1.The Killing of Microbes on Copper Surfaces

Contact killing of microbes by copper surfaces

 
   

Species

Killing time*

Salmonella enterica

4 h

Campylobacter jejuni

8 h

Escherichia coli O157

65-75 min

MRSA

45 min

EMRSA-1

60 min

EMRSA-16

90 min

Listeria monocytogenes

60 min

Mycobacterium tuberculosis

5 to 15 days

Candida albicans

60 min

Klebsiella pneumoniae

60 min

Pseudomonas aeruginosa

180 min

Acinetobacter baumannii

180 min

MRSA

180 min

Influenza A virus (H1N1)

6 h

Source: Metallic Copper as an Antimicrobial Surface.

*Or undetectable.

 

2. Copper is expensive
Copper pipes have to be locked up on construction sites to prevent theft. Scrap metal suppliers will buy copper at $2.15 a pound, where as aluminum only commands $0.68 a pound. 

3. Maintenance costs
Copper easily and quickly acquires a greenish patina of copper oxide. While that does not seem to lessen any of its microbial lethality, it makes facility managers want to scrub the surface back to a lustrous copper sheen. So, there are higher maintenance bills for copper. Stainless steel is (deceptively) clean-looking with no scrubbing or maintenance whatsoever.

4. Misconception that copper is toxic
While trace amounts of copper are vital to most organisms, large amounts can be poisonous but copper surfaces won’t hurt humans, except for those with Wilson’s disease, a recessive genetic disorder characterized by an inability to eliminate copper from the body resulting in toxic levels of copper in the liver and brain.

Until the day we find more copper being used on public surfaces, we must remember that the best bet to keep yourself virus free is still by washing your hands with soap and water.   

 

References

Copper Destroys Viruses and Bacteria. Why Isn’t It Everywhere? Shayla Love, Vice.com March 18, 2020.

Metallic Copper as an Antimicrobial Surface, Gregor Grass, Christopher Rensing, and Marc Solioz, Applied and Environmental Microbiology, March 7, 2011.

Significance of Fomites in the Spread of Respiratory and Enteric Viral Disease, Stephanie A. Boone, Charles P. Gerba, Applied and Environmental Microbiology, March 13, 2007.

 

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