The Microcosmos at Our Fingertips

I conducted this project as part of Professor Pringle’s EEB321 class at Princeton University. In the age of the coronavirus pandemic, how “clean” the surfaces we come into contact with every day has been at the forefront of people’s minds more and more. This is also an obsession of popular science, as fear mongering about cleanliness and contamination seems to increase website visits and reads. A simple Google search for the terms “how dirty is your keyboard” and “keyboard bacteria study” reveal headlines claiming that a computer keyboard is 20,000 times dirtier than a toilet seat. Clicking on such articles quickly reveals that these headlines are slightly facetious, representing outliers in often-referenced studies. Furthermore, research into the bacterial and viral load of keyboards, when compared to toilets, likely ignores the fact that toilets tend to be cleaned more often and with more powerful antimicrobial agents than keyboards.

But as I use my computer every day, and more so given the nature of remote school, work, and even social life, I could not help but wonder what, exactly, is on my computer keyboard, especially considering that I have not cleaned my keyboard in a long time. To investigate what is on my keyboard, I prepared a slide of some dust in the computer crevice and looked at it through the Foldscope. Unfortunately, I was not able to identify much in the image other than what appeared to be hair, but it looked similar to another slide of dust from the floor. Because of this, I hypothesize that what is on my keyboard is not much different from what is (harmlessly) on my floor.

Foldscope image of dust collected from my computer keyboard.
Foldscope image of dust collected from my floor.

Because of this, I hypothesize that what is on my keyboard is not much different from what is (harmlessly) on my floor. Research seems to support this, as a study by Ide et al. (2019) of keyboards in healthcare settings found that the most common make up of keyboard microbial contaminants were skin commensals. Bacteria was also found, as expected, but it was also found that various disinfection methods were inconsistent, and there was little evidence on the link between device contamination and human colonization or infection.

This is important to note because the obsession our society has with cleanliness has caused an increased in immunopathology and weakened immune systems that may be making us all more prone to epidemics and pandemics. Of course, it is important to avoid pathogens, as the effects of infection can be deadly. But learning to live with the worms and germs we have been living with for most of evolutionary history will do us all well.  

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