Phone Bacteria

How Dirty is Your Phone?

Research Reveals How Much Bacteria is on your Phone

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  • 100% of phone screens tested contained E. coli and fecal streptococci – both found in human and animal POOP!
  • 50% of the phones contained excrement from cockroaches
  • All phones tested positive for S. aureus – a cause of pneumonia
Harmful Bacteria

Research Reveals Types of Harmful Bacteria on Phones

It's safe to say that we use our phones a lot, from sending a quick text message to scrolling through seemingly endless feeds of cat videos, our mobile phones have become an integral part of our lives that we seemingly can't go five minutes without. Many of us continue to use our phone while we eat, and perhaps even while we go to the bathroom.

We may think that we're cleaning the screen thoroughly enough after using it, but is that really the case, or are we really growing bacteria breeding grounds right beneath our fingertips?

To find out, conducted lab research on twenty swabs collected from ten randomly selected mobile phone screens within an office setting. The participants in the sample consisted of five women and five men, with the ages ranging from 22 to 62 years old. The results are fascinating, although we must warn you that they're not for the faint of heart!

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Purpose of research

The research consisted of two sterile bacterial collection swabs being taken per mobile phone screen of ten randomly selected individuals – making a total of twenty swabs across ten phone screens.

Multiple swabs were used for each screen to ensure that an accurate sample of bacteria was collected. The swabs were then placed into a developing fluid and sent to a bacterial analysis laboratory. The results are measured in CFU (Colony Forming Units). The lab research was conducted in February 2023.

The data collected through this research will give an insight into the common types of bacteria that are found on mobile phone screens, alongside detailing the potential risks associated with allowing these bacteria to grow.

Phone Bacteria

Revealing the Bacteria Playground Thriving on your Smartphone Screen

Summary of findings:

  • 50% of phone screens contained bacteria P. aeruginosa – commonly found in cockroach feces.
  • 100% of phone screens contained E. coli and fecal streptococci – both found in human and animal fecal matter.
  • None of the phone screens contained traces of Salmonella.
  • Bacillus cereus, responsible for intense food poisoning, was found on 100% of phone screens.
  • S. aureus – a cause of pneumonia – was present in 100% of phone screens sampled.
Toilet Roll

How harmful is it to bring our phones to the toilet?

It's something most of us are guilty of doing, at least occasionally, but should we really take our phones into the bathroom with us when we need to use the toilet? While we tend not to think anything of mindlessly scrolling through our social media feeds or replying to DMs when we're on the toilet, our research found that the secrets of what we get up to in the bathroom are often physically left behind on our phone screens – and that may actually come with health complications down the line.

While we may not see the harm in taking our phone for a quick 5-minute trip to the bathroom, we could be exposing our phone screens to any of the following bacteria:

  • Escherichia coli (E. coli)
  • Fecal streptococci and Enterococci

Both of these bacteria strains are commonly found in fecal matter – human fecal matter! These bacteria land on our phones, usually when we flush the toilet and they become airborne. We then carry them with us, on our phone screens, out of the toilet and into the rest of our homes, where they could even be responsible for spreading diseases!

Not only is this an unpleasant image in terms of bacteria living on our mobile phones, it also shows that many of us could be walking around with our own fecal matter on our screens… Screens that we then bring up to our faces to make calls – yuck!

Escherichia Coli (E. coli)

Escherichia Coli (E. coli)

One of the most common bacteria cultures found on the cell phone screens in the study was escherichia coli, also known as E. coli. This bacteria was found on every phone screen in the sample, with each swab taken containing a concentration of less than 10 colonies (CFU). Despite the relatively small culture size, this doesn't detract from the potential risks associated with this bacteria.

E. coli is a very common bacterium, with the majority of its variants being entirely harmless. However, many of the harmful variants of this bacteria occur in fresh fecal matter, meaning that finding this bacteria on your phone screen is a relatively good indicator that there is also fecal matter present.

While this alone doesn't necessarily mean you're likely to contract any of the ailments associated with E. coli contamination – which include diarrhea, vomiting, and even urinary tract infections – it's not exactly a pleasant thought to know that your phone screen could be laced with feces!

With our research finding E. coli colonies on each phone screen, this highlights just how prevalent it is for us to take our mobile phones with us to the bathroom and not clean them thoroughly afterwards, with the potential for some nasty side effects.

Fecal Streptococci & Enterococci

Fecal Streptococci & Enterococci

Fair warning – this one is quite squeamish. We found traces of fecal streptococci on all of the 10 phone screens we took samples from. Each swab had concentrations of under 20 colonies (CFU).

As you may have guessed from the name, fecal streptococci and enterococci are bacteria that form in the stomach and intestines of both humans and animals, and are most commonly found in fecal matter. Unfortunately, finding this bacteria on your phone screen is a pretty good indicator that there is feces on your screen.

Given the presence of E. coli cultures, it was already fairly safe to assume that fecal streptococci would also be found – and while this bacterium may not be solely responsible for any ailments, that doesn't make it any more reassuring!

Staphylococcus Aureus

Staphylococcus Aureus

Another bacterium that was present on every phone screen in the sample was staphylococcus aureus, also known as S. aureus. Our research found less than 20 colonies of this bacteria on each swab taken from the phone screens in the sample, significantly higher than the number of E. coli colonies discovered.

S. aureus can present itself as a pathogenic bacteria, contributing to the risk of ailments including food poisoning, respiratory infections, such as pneumonia, and even skin infections. It can also be the underlying cause of many common minor skin conditions, such as acne, boils, cellulitis, and folliculitis.

Unlike other bacteria, the incubation time for S. aureus is very short, lasting between 1 to 6 hours. After that, the duration of the illness can vary anywhere between 30 minutes to 3 days. Due to its potential pathogenic nature, the likelihood of contracting an illness associated with S. aureus is relatively high.

Although the concentrations of bacteria found on the phone screens in our research were still fairly small, there is the possibility of developing an illness from even a small amount of contamination.

Bacillus Cereus

Bacillus Cereus

Another very common bacteria was bacillus cereus. Our research found colonies of bacillus cereus on each of the 20 swabs taken from the phone screens. Each swab contained less than 20 B. cereus colonies (CFU).

This bacteria is most commonly found in food and soil, and many variants are harmless. Certain varieties of B. cereus can cause foodborne illnesses, and can cause symptoms such as vomiting, nausea, and diarrhea.

Typically, these harmful variants are often associated with undercooked food, so finding traces of this bacteria can be an indicator that you could be putting yourself at risk of food poisoning.

Clostridium Perfringens

Clostridium Perfringens

We found clostridium perfringens, also known as C. perfringens, on each phone screen that was swabbed for this study. Specifically, there were under 10 colonies of this bacteria on each swab collected. Again, this is a relatively small number of colonies, but when we think about the small surface area on our phone screen, this becomes a bigger issue.

This bacteria is interesting, as it naturally occurs in both decaying vegetation and the human intestinal tract. However, this bacteria is far from friendly, and is one of the most common causes of food poisoning. Unlike other foodborne bacteria, C. perfringens forms bacteria spores that can withstand cooking temperatures. This bacteria germinates as cooked food is left to stand, rather than resulting from undercooked food.

Symptoms of contamination from this bacteria can be quite unpleasant, including abdominal cramping, vomiting, fever, and diarrhea. These symptoms can take up to 24 hours to subside, which can result in a miserable time for those that come into contact with this bacteria.

Pseudomonas Aeruginosa

Pseudomonas Aeruginosa

One of the more interesting bacteria colonies discovered during this research was pseudomonas aeruginosa (P. aeruginosa). This bacterium was only present in 50% of the phone screens sampled, with the concentrations varying. Four of the phone screens contained over 3.0x10^3 colonies (CFU) of P. aeruginosa, while another had 2.5x10^3 colonies (CFU).

Interestingly, of those that had this bacteria present on their phone screen, the majority were men. Three male participants and two female participants had P. aeruginosa colonies on their phone.

This bacteria is far less common than the others discovered, and is typically found on cockroaches or in their feces. This particular bacteria can be harmful to those that are immunocompromised, as it's an opportunistic bacterial pathogen. Prevalent symptoms of exposure to P. aeruginosa include respiratory and urinary tract infections, and a form of dermatitis commonly referred to as 'hot-tub rash'.

It was interesting to find fairly high concentrations of this bacteria on half of our sample, and begs the question of whether we should add ‘cockroaches crawling over the screen when we're not looking' to our list of mobile phone safety concerns!

Finally, our samples were also tested for salmonella. This bacteria is one of the most common causes of severe food poisoning, and can lead to symptoms including stomach cramps, fever, vomiting, nausea, and diarrhea. Infection usually occurs when this bacteria is consumed through contaminated food or by touching a surface that has been contaminated.

Thankfully, none of the mobile phone screens in our study contained any traces of salmonella. Typically associated with raw meats and poultry, such as chicken, alongside uncooked eggs and dairy, it seems that we tend to tread more carefully when handling raw foods around our phones.

Phone Bacteria
Bacteria Potential health risks
Escherichia Coli (E. coli) E. coli contamination can cause diarrhea, vomiting, respiratory infections, and even urinary tract and bloodstream infections in humans
Fecal Streptococci & Enterococci Fecal Enterococci can cause diseases of the skin, eyes, respiratory tract, and ears. These pathogens are a common cause of urinary tract infections, endocarditis (infection of the lining of the heart), and bacteremia (infection of the bloodstream). If these bacteria are able to enter a wound, they can also cause wound infections.
Staphylococcus Aureus Staphylococcus Aureus is the leading cause of skin and soft tissue infections, such as cellulitis, abscesses, and furuncles. Most infections are minor, though they can potentially develop into infections of the bloodstream, pneumonia, and even bone and joint infections.
Bacillus Cereus Bacillus Cereus is a foodborne pathogen that has the potential to produce toxins. These can cause two types of gastrointestinal illness: emetic (vomiting) and diarrhoeal syndrome (diarrhea). Symptoms usually occur quite rapidly after ingesting contaminated foods.
Clostridium Perfringens Clostridium Perfringens is one of the most common causes of food poisoning worldwide, resulting in symptoms such as vomiting, diarrhea, fevers, and lethargy.


Skull & Crossbones

Are our phones a danger to our health?

Our research found a shocking number of different types of bacteria thriving on the screens of multiple randomly-selected mobile phones, many of which can cause some pretty awful side effects. While this does appear concerning, it's unlikely that the quantity of bacteria found on these screens is enough to cause any real damage.

Ultimately, what we've learned from this research is that it really is important to keep on top of cleaning and sanitizing our smartphones – especially if we're one of the many that are guilty of taking their iPhone on a quick expedition to the bathroom! This can be done easily and quickly, using disinfectant wipes.

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SellCell collected swab samples from the phone screens of ten individuals between the ages of 22 and 62. Four of the participants were male, with the remaining six participants being female. Two samples were collected from each phone screen using sterile swabs as part of a bacteria collecting kit issued by SYSCO Environmental. These swabs were stored in a developing fluid before being processed in a laboratory. Results were measured in CFU (Colony Forming Units). The lab research was conducted in February 2023.