Right now, there may be poop on your cell phone (and oh so much more).

by Ashley Cummings on October 2, 2012

Image courtesy of jannoon028/FreeDigitalPhotos.net

The dangers of cell phone distractions while driving are widely publicized, but could your mobile device be a health hazard in other ways?

BREAKING NEWS — Your mobile phone may have poop on it. Yes, that’s right. That little gadget that makes you feel naked if you leave the house without it, could be harvesting E. coli and infectious diseases.

You hold it up to your face. You use it while you’re eating lunch. Maybe you even take it with you to the bathroom…

An article published in the NED Journal of Research, “Mobile Phones: Reservoir of Infectious Diseases in University Premises”, tested the phones of 367 university students, teachers, and staff members. The major findings from this study were:

  • 98.6% of phones were contaminated in some way.
  • Coliform bacteria were present on 69% of phones. Example: E. coli from some form of fecal matter, which may cause an upset stomach.
  • Corynebacterium diphtheria was present on 51% of phones. Translation: causes diphtheria, an upper respiratory tract illness, which commonly includes a sore throat, mild fever and swelling of the tonsils, pharynx, or nasal cavity.
  • Coagulase negative staphylococcus was present on 42.2% of phones. Translation: commonly found on skin and in mucus membranes, and is relatively harmless, except for those with weak immune systems.

So, what are the possible explanations for this bacteria being present?

  • Not washing hands after using the restroom.
  • Phone use while sick (breathing, coughing, sneezing).
  • Setting the phone on contaminated surfaces (kitchen counter, bathroom counter).
  • Touching an infected surface, then touching the phone (a desk, your nose, a door handle).
  • Rarely or never disinfecting the phone.
  • Using the device continuously for over 2 hours.
  • Heat from hands and the phone itself increases bacteria, which already has the ability to live for months.

What should you take away? There are both good and bad types bacteria. Flush away bad bacteria by not taking your phone with you to the bathroom, washing your hands often, kindly not sharing your phone with someone who is sick, and by disinfecting it often (wipes work well).

Be especially careful when coworkers or peers are beginning to sniffle or complain of a sore throat. Don’t let the cold and flu season take over your campus or office this year!

Now, I would be lying if I said I wasn’t a germophobe, but if germs and bacteria don’t scare you…just picture the poop.


Kahn, S. & Shaihk, A. A. (2012). Mobile Phones: Reservoir of Infectious Diseases in University Premises. NED University Journal of Research 9(1), 35-43.

John Spevacek October 2, 2012 at 9:36 am

Chemists, physicists, pharmacists and doctors have long understood the concept “it’s the dose that make the poison”, meaning that exposure to a certain chemical or radiation in small enough doses does no harm.

Biologists have never caught on to this. Sure, there is e. coli etc. on the phone, but is it enough to make you sick? If it isn’t enough – and judging by the fact that nearly everyone uses a phone and yet most people are’t sick – then this is just promoting germophobia.

Andy Tauscher October 2, 2012 at 6:36 pm

You bring up a valid point about the dosage. However, just because everyone using a cell phone isn’t sick at the exact same time, doesn’t mean that the fecal matter on the phones doesn’t contribute to illness.

In fact, everyone gets sick with something at some point or another, so it my very well contribute to the spread of these diseases. This post doesn’t seem to claim any epidemic here, just that fecal matter on phones could be a contributing factor.

Ashley Cummings October 4, 2012 at 2:20 pm

John, thank you for your feedback.

More research must to be done on whether or not participants got sick at any point as a result of the germs from their phones. Nonetheless, this is something to be aware of, say while eating lunch if you’re touching your phone and your food… It won’t make a difference if you washed your hands or not beforehand.

I have to agree with Andy’s point that it does not mean everyone should be sick, it just means that at some point we all get sick and germs on phones could have something to do with the spread, especially during cold and flu season.

Ginny Kendall October 2, 2012 at 10:17 am

How do you safely disinfect a cell phone?

Ashley Cummings October 2, 2012 at 2:01 pm

Clorox wipes should do the trick.

Quintus October 2, 2012 at 11:14 am

Should you not have written “Germophone”?
Nice post, but again I cannot access your prime reference material without going through the Universities web portal. I would really advise everyone to reference as much open access material as possible. This, I realise, may be difficult in most cases, but try and find some.

Michael Grisafe October 2, 2012 at 11:35 am

Hi Quintus,

Hang tight! I am working on a post (out in one or two weeks talking about open sources of science information and journals).

John Spevacek October 2, 2012 at 1:04 pm

It more than just open sources – it’s making sure that the sources DO NOT run us into the U of M web portal. Please link directly to the article on the publisher’s website.

Ashley Cummings October 2, 2012 at 2:04 pm

The link should now provide the abstract, I’m still working on finding free public access to the full text.

John Spevacek October 3, 2012 at 8:51 am

In all seriousness, lots of luck with that. It will probably not happen.

Enjoy all the access that you currently have, because once you are no longer affiliated with a large university, the access will be greatly reduced or non-existent.

Margaret October 2, 2012 at 12:32 pm

Hi Ashley,
I get a little nervous with over use of antibacterial wipes and gels. This might be a little of topic, but it would be nice to know which is worse the bacteria or the over use of antibacterial gel/soap? Also, your link to the pharynx is to the pharynx in other animals. I realize that there is a lot of bacteria everywhere. I was surprised that some of the phones were not contaminated. I wonder what those owners did that was different.

Great idea for a post. I don’t know anyone without a cellphone.


Ashley Cummings October 2, 2012 at 8:02 pm

Overuse of antibacterial cleaners would be a great topic for another post!

Rick October 3, 2012 at 8:31 pm

Hi Ashley,
Sorry to be the style guy, but I think any piece of writing intended to inform us on scientific issues has to display a certain amount of precision in the use of language. In your bulleted list, the sentence fragments after “Translation:” aren’t actually restatements of the original sentence (because they don’t make any mention of phones) but are actually supplementary information. If you were to claim, for example, that “Your phone is responsible for that case of diphtheria you suffered from last week”, then I guess the “Translation:” formulation would work. As it is, though, I think it serves more as a hindrance to understanding than a help.

How about reformulating as, for example, “Coagulase negative staphylococcus is commonly found…”? If you think that repeating the technical term is over the top, then “This bacterium (“bacteria”, if you must!) is commonly found…”

I know a lot of these style matters are a matter of taste, but it seems to me that in this case you’re throwing away precision for no real gain. Feel free to disagree, though, if you like it how it is!

Ashley Cummings October 4, 2012 at 2:23 pm

Thank you for your input, Rick. This is something I will try to be more conscious of in future posts.

Rick October 3, 2012 at 8:37 pm

I would also really like to read a post of antibacterial cleaners. This may be a slightly different matter, but most Japanese universities now have either chlorine-based (in the case of thrifty universities such as my own) or ethanol-based (in the case of richer universities) cleaners. I heard somewhere that ethanol-based cleaners cannot kill a norovirus, which would be interesting if true and if I knew what a norovirus was.

The economics of this question also puzzles me. A non-medicated liquid soap costs three times as much as a medicated one (again in Japan).

Lauren C. October 5, 2012 at 7:46 pm

Hi Ashley,
I think your post brought up an issue that many people do not think about on a daily basis. I take my phone everywhere with me and I am also surrounded by germy kids at school all day. I don’t think this post promoting germophobia, I think it is just making us more conscience of things that could make us sick. There are so many ways we can become sick, so why not eliminate one!

Thanks for reminding me to clean my phone! It’s so easy to forget!

Ashley Cummings October 6, 2012 at 11:24 am

Hi Lauren C.,

Thank you for commenting! I am glad I could help remind you to clean your phone every once in a while. As a teacher, this may be a good thing to pass along to your colleagues, and even possibly your kids (I’m sure some already own cell phones)!

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