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Who ever knew there was a reason behind brass door knobs and banisters

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This bit of fact came to me in one of the newsletters I get and I was fascinated by how it was first discovered in the old days. 


In 1852, physician Victor Burq visited a copper smelter in Paris's 3rd arrondissement, where they used heat and chemicals to extract the reddish-brown metal. It was a dirty and dangerous job. Burq found the facility to be "in poor condition," along with the housing and the hygiene of the smelters. Normally, their mortality rates were "pitiful," he observed.

Yet, the 200 employees who worked there had all been spared from cholera outbreaks that hit the city in 1832, 1849, and 1852. When Burq learned that 400 to 500 copper workers on the same street had also mysteriously dodged cholera, he concluded that something about their professions—and copper—had made them immune to the highly infectious disease. He launched a detailed investigation into other people who worked with copper, in Paris and cities around the world...

In the 1854 to 1855 cholera epidemic, Burq could not find any deaths of jewellers, goldsmiths, or boilermakers—all those who worked with copper. In people in the army, he found that musicians who played brass instruments (brass is partly copper) were also protected.

In the 1865 Paris epidemic, 6,176 people died of cholera, out of a population of 1,677,000 people—that’s 3.7 people out of every 1,000. But of the 30,000 who worked in different copper industries, only 45 died—an average of around 0.5 per 1,000....

Today, we have insight into why a person handling copper day in and day out would have protection from a bacterial threat: Copper is antimicrobial. It kills bacteria and viruses, sometimes within minutes. In the 19th century, exposure to copper would have been an early version of constantly sanitizing one's hands.

Since then, studies have shown that copper is able to destroy the microbes that most threaten our lives. It has been shown to kill a long list of microbes, including norovirus, MRSA, a staph bacteria that has become resistant to antibiotics, virulent strains of E. coli that cause food-borne illness, and coronaviruses—possibly including the novel strain currently causing the COVID-19 pandemic.

Of course the problem with copper/brass fixtures and surfaces is they oxidize and look 'dirty' as they slowly turn green.

The article surmises "so what? ... it retains its anti-microbial properties regardless of whether it has been polished or not."

The realization is that most folks never realized why door knobs and the like used to be commonly made from brass.  Of course now, if you look at most  institutions like schools and hospitals avoid the brass fixture opting for stainless steel. The belief, I guess, is because you typically make surgical instruments out of stainless steel (medical folks typically sanitize them by dropping them in boiling water for a few minutes), people think of these items as 'clean' while brass/copper items would likely oxidize and look 'dirty'.


items closest to a patient were the most contaminated with microbes—those were the bed rails, the nurse call button, the arm of the visitor chair, the tray tables, and the IV pole. Enveloping these items in copper reduced the presence of microbes by 83 percent. As a result, HAIs were reduced by 58 percent, even though the researchers had introduced copper to less than 10 percent of the surface area of the room.

We have other methods of killing bacteria and viruses to mitigate HAIs, including ultraviolet light and hydrogen peroxide gas. But both require a hospital room to be empty, and once sick people re-enter rooms, surfaces can easily be contaminated again. “Copper is continuously working 24/7 without supervision, without any need to intervene, and it never runs out,” Schmidt said. “As long as the metal's there, it's good to go."

So given how well it could work, for hospital infections and for health more generally, why isn’t copper everywhere? Why isn’t every door knob, every subway rail, every ICU room, made of copper? Why can we easily buy stainless steel water bottles, but not copper? Where are the copper iPhone cases?

It doesn't seem like we'll run out of copper in the near future, according to the World Copper Factbook from 2019. Copper is one of the most recycled of all metals—nearly all copper can be recycled and not lose any of its properties.

Doctors and healthcare workers might not be aware of its properties, as Keevil wrote in The Conversation: “When doctors are asked to name an antimicrobial metal used in healthcare, the most common reply is silver—but little do they know that silver does not work as an antimicrobial surface when dry—moisture needs to be present."


This effect of brass is so powerful, there is even some outfit suggests that you can use something like a 3 oz brass coin that you rub on and around your hands for a minute and it will 'saniitize' your hands to one degree ... i.e. it will kill like 84 percent of the microbes on your hand by this action of rubbing on your hands like a bar of soap.  This is not perfect but obviously in the game of odds, killing 84 % of the covid-19 virus is better than not.  I don't know if it would work, but I suspect that you go to your old penny jar, take out the coins older than 1980, and shove some in each of your pockets. Then, stand around and 'wash' your hands in your pockets with coins like you're a poor duck named Donald whose rich uncle is known as scrooge.

There are going to be some new things that may help us out of this, if the folks in charge are smart enough to make it happen. More on that in a later post.

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Apparently the ability of copper to act as a antimicrobial did not escape the attention of some 3D computer printer designers who've come up with an inherently copper-infused anit-microbial, re-usable N-95 mask.  Since viruses can't tolerate the presence of copper, the designers created a 3D print medium that includes copper which kills coronaviruses including Covid-19.

Because it is plasticized the resulting mask can be fitted to each individual's face by heating the unit, which gives it some remolding flexibility.

Yep, it appears that relatively soon one will be able to buy some 3D printer filament and computerized design software (and a capable 3D printer) and print out this new kind of N95 mask that can be re-used many times.


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