Most of us recognize the importance of washing our hands throughout the day. We keep antibacterial soap by our sinks and hand sanitizer in our pockets. Then, after we press the flesh at networking events or finish our bathroom duties, we pretend we're a doctor scrubbing for surgery. But sometimes we're less fastidious when we encounter objects that seem beyond the reach of bacteria and viruses. In reality, we come in contact with an array of fomites -- materials or surfaces that are likely to carry infection -- every day of our lives.
On the next few pages, we have a list of 10 things you might think are benign but are actually crawling with bacteria and other wee-beasties. Our first stop will make you think twice about getting that cool, refreshing drink of water from a public fountain.
Charles Gerba, professor of microbiology at the University of Arizona, is a bacteria bigwig. In the 1970s, he warned us about toilet plumes -- clouds of contaminated water that fill our bathrooms every time we flush stuff down the loo. A few years later, he revealed the microbial landmines lurking in our kitchens, on sponges, cutting boards, countertops and sinks. And then he opened our eyes to the invisible, disease-carrying world found on TV remote controls in hotel rooms.
More recently, Gerba turned his attention to the workplace. In research sponsored by consumer product company Kimberly-Clark Professional and conducted as part of The Healthy Workplace Project, the microbiologist and his associates swabbed close to 5,000 surfaces in several office buildings with at least 3,000 employees. Back in the lab, they tested the swabs for adenosine triphosphate, or ATP, a chemical found in all living cells and therefore an indicator that bacteria, yeast and mold were likely present on the item tested. An ATP reading of 100 indicated a dirty object; a reading of 300 or higher indicated a filthy object [source: Castillo].
Of the water fountain buttons tested by the researchers, 23 percent earned ATP readings of 300 or more. A little more than half scored 100 [source: Castillo]. Either way, it's a sure sign that the water cooler is a great place to catch some gossip -- and your next cold. Just use your shirtsleeve and remember to wash the shirt later.
When you're working your five-speed transmission like Sammy Hagar in a black Ferrari, the last thing on your mind is microbial infection. Then again, you might want to wear some gloves the next time you grab the stick and rev the engine or, at the very least, wash your hands thoroughly when you arrive at your destination. Why? Because the operative word in "manual transmission" is "manual." Even on a short trip, your hand spends a lot of time caressing the gearshift knob -- and picking up microorganisms that might be living there.
A tiny 2010 experiment in the U.K. supports this idea [source: Whitcroft]. Scientists swabbed 12 ordinary items in a suburban family's home, then tested those items for the presence of bacteria, including E. coli and Staphylococcus aureus, and two types of molds, aspergillus and penicillium. One of the things they tested was the gearshift knob of a 3-year-old Saab. Turns out, the knob was contaminated with high levels of bacteria and very high levels of molds. The researchers surmised that drivers pick up mold spores on their way to their cars. They then carry those spores into the vehicle and seal themselves inside with the contaminants. If you suffer from allergies or other respiratory problems, driving 55 may be the least of your worries.
They say the pen is mightier than the sword, and thanks to Dr. J. Owen Hendley, a professor of pediatrics at the University of Virginia, we now have another reason to believe it's true. In 2006, Hendley co-authored a study investigating the prevalence of rhinoviruses -- the germs responsible for the common cold -- in hotel rooms. Here's what Hendley and his team did: They asked 15 people with confirmed colds to spend the night in a nearby hotel. After the sniffling, sneezing guests checked out, scientists entered the rooms before the cleaning staff and tested various surfaces for the presence of rhinoviruses. As you might expect, they found virus particles on door handles, TV remotes, light switches, phones and alarm clocks. But they also found a large number on hotel pens [source: Associated Press].
By extrapolation, it's safe to assume that other communal pens -- at banks, grocery stores, day-care centers, restaurants and department stores -- are just as infected. In fact Dr. Neil Schachter, a pulmonary disease specialist at Mount Sinai Hospital, recommends that you should carry your own pen at all times and "use it instead of the doctor's, the delivery guy's or the restaurant waiter's" [source: Prevention].
In 2009, Charles Gerba was at it again. This time, he teamed up with research scientists Kelly Bright and Stephanie Boone to see if disinfecting wipes could help control the spread of infectious diseases in elementary school classrooms. Their study focused on six classrooms in one Seattle school. Three of those rooms were part of the control group and received no intervention. The other three were thoroughly cleaned each day by parent volunteers who scrubbed 12 test surfaces with disinfecting wipes containing quaternary ammonium, a chemical compound often used in disinfectants, surfactants, fabric softeners, antistatic agents and wood preservatives [source: Bright et al.].
Over seven winter weeks, the scientists swabbed the test surfaces in both the control and experimental classrooms several times. They sent the samples to a lab, where they were analyzed for the presence of bacteria and viruses. Their results confirmed what we already know from the first entry on our list: Water fountain buttons were hotbeds of microbial activity. Surprisingly enough, the next most contaminated object per square centimeter in the classroom was the manual pencil sharpener handle. The least contaminated objects were the classroom entrance and exit doorknobs. How was this possible? Gerba and his colleagues noted that the doors in the classrooms were usually propped open, so they escaped being touched throughout the day. The pencil sharpeners weren't so lucky. Kids used them constantly and, as a result, left behind more than just a few graphite shavings [source: Bright et al.].
OK, let's get this straight. After you use the facilities -- especially public facilities -- you need to wash your hands, correct? But what do you do if the soap in the dispenser next to the sink carries as many germs as the toilet where you did your business? This isn't such a far-fetched question, according to some researchers at the University of Arizona. After sampling 132 refillable soap dispensers in public restrooms and restaurants, they found 23 percent were contaminated with viable bacteria, including Serratia marcescens, Enterobacter aerogenes and Klebsiella pneumoniae [source: Hoyle]. These are all pathogens, by the way, which means they're capable of causing disease.
More disturbing, the researchers don't think the germs are surviving in spite of the soap. They believe instead that the bugs are metabolizing chemicals in the soap to stay fat and happy. So where does that leave you when you're emerging from a public restroom stall? Look for dispensers containing sealed disposable bags, which tend to be bacteria-free. If they're not available, carry some alcohol-based sanitizer and use that on your hands. Using water with no soap, even hot water, will do little to remove bacteria from your skin.
We've all heard the horror stories of people getting injured on a moving escalator. How about this item from the July 3, 2013, edition of the New York Daily News: "A 32-year-old woman was chewed up by an escalator in a Harlem subway station Wednesday after she collapsed and her hair got snagged in the moving stairs." As painful as this sounds, such accidents are uncommon. But that doesn't mean escalators won't try to hurt you.
Recent research suggests that escalator handrails fall just behind restroom sinks and food court tables as the filthiest objects in a mall. When scientists have tested the hard rubber cover that makes up a rail, they've found a menagerie of disgusting items -- food, blood, mucus, urine and feces. They've also found potentially pathogenic bacteria, such as E. coli and bugs common to the upper respiratory tract [source: Dineen]. Taking the stairs seems like a good solution until you remember that you'll have to deal with another handrail. And the elevator is a germ incubator complete with bacteria-infested buttons. Best to stick with the escalator -- and stay away from the handrail.
What's good for your hands must also be good for your clothes, right? Not so fast. For one thing, your washing machine receives dozens of garments every time you do laundry. That means it must clean an area far bigger than your hands. And don't think a dirty T-shirt carries fewer bacteria than skin. According to germ guru Charles Gerba, a load of undergarments transfers about 500 million E. coli bacteria to the machine [source: Roberson]. If you're using a front-loading machine, which can't always expel all of the water from one wash cycle, these bacteria take a leisurely swim until the next load arrives. In essence, you're washing dirty clothes with contaminated water.
A better solution (aside from throwing away clothes after each use and starting over with new ones) is to wash whites first in chlorine bleach. Follow this up with a load of underwear, using hot water and color-safe bleach substitute. Once a month, you should add bleach and run an empty cycle. This sanitizes your machine and helps to reduce the number of bacteria found on your clothes.
Ducklings and chicks rank high on the list of the cutest animals ever. They're soft, fuzzy and full of plaintive peeps. According to the Centers for Disease Control and Prevention, they're also breeding grounds for salmonella, a bacterium that often causes food poisoning. The birds release the germs in their droppings, but their entire bodies can become contaminated because, well, they play where they poop. If you cuddle or -- gross -- kiss your feathered friends, you run the risk of picking up some bad bacteria. Salmonella germs cause a diarrheal illness that can be mild, severe or even life-threatening, especially in very young or very old people.
If you can't resist touching the baby birds, be sure to wash your hands thoroughly with soap and warm water. In lieu of washing, use alcohol-based hand sanitizer until you can get to a sink. And never let live poultry inside your house or anywhere where food is prepared, stored or served. That means you shouldn't let ducklings and chicks party on your patio or hang out in your beer cooler.
Everyone loves a full wallet -- the decadent smell of leather and currency, the pockets bulging with credit cards, the change pouch rattling with coins. If you're lucky enough to carry such riches, you might want to consider the other bounty in your billfold. Research now suggests that your folding money may be a playground for pathogens. One 2002 study conducted in western Ohio found that 94 percent of $1 bills contained disease-causing bacteria [source: Bryner]. Another study in England proved that the problem is universal. Scientists there swabbed the hands, currency and credit cards of 272 people in London, Birmingham and Liverpool, then tested for the presence of fecal bacteria. As you might expect, the subjects' hands were pretty disgusting, but 8 percent of the swabs from the cards and 6 percent of the swabs from the bills had as much fecal bacteria on them as you would find in a dirty toilet bowl [source: Chan].
Coins carry their fair share of germs, as well. African researchers analyzed coin samples taken from a variety of street vendors and other locations in a residential neighborhood in Nairobi [source: Kuria]. They isolated a number of potentially pathogenic bacteria, including E. coli, klebsiella, salmonella and staphylococcus. They also found residue from fungal strains known to cause diseases, leading them to recommend good hand hygiene for anyone handling coins all day long. This is especially important in restaurants, where people who exchange money with customers also prepare food.
Oh, the ivory towers and hallowed lecture halls of college, where we learn about calculus, medieval history, astronomy and, um, beer pong. In this popular drinking game, a player on one team tries to toss a Ping-Pong ball into cups of brewski lined up on a table. If he or she makes it, a player on the opposing team has to swill the beer (after removing the ball, of course). Except for some drunk and disorderly behavior beer pong might produce, it's a perfectly harmless game, right?
Apparently not, according to Clemson University students who recently tested balls used in games across their Tiger Nation. During homecoming weekend, the scientists-in-training roamed the campus to find games in action and collect samples for their study. They then took the Ping-Pong balls to the lab and tested them for the presence of bacteria. On a typical ball used in outdoor games, students found up to 3 million bugs living on the surface. On a ball used indoors, on carpeted surfaces, they found just 200 bacteria. And don't kid yourself into thinking that germs don't like to swim. In a separate part of the experiment, the researchers found a high level of ball-to-beverage transfer [source: Collins]. Who said higher education was doomed?
Many people think Marie Antoinette's hair turned white overnight. Find out if this could really happen at HowStuffWorks.
Author's Note: 10 "Harmless Things You Should Wash Your Hands After Touching
As I wrote this article, I kept thinking about my high school job in the sub shop. These were the days before restaurant staff routinely wore gloves, so our hands were constantly in the food. Given that we were all a bunch of teenage dorks who could barely remember to close and lock the back door, much less wash our hands throughout a shift, I'm amazed the place wasn't shut down.
- "10 Ways You're Wrecking Your Immune System." Prevention. December 2011. (July 7, 2013) http://www.prevention.com/health/healthy-living/top-10-worst-habits-your-immune-system/6-you-dont-carry-pen#ixzz2YqumGR2I
- Associated Press. "Study: Hotel Guests Leave Germs, Viruses Behind in Rooms." Fox News. Sept. 29, 2006. (July 7, 2013) http://www.foxnews.com/story/2006/09/29/study-hotel-guests-leave-germs-viruses-behind-in-rooms/#ixzz2YquMqeyn
- Bright, Kelly R., Stephanie A. Boone and Charles P. Gerba. "Occurrence of Bacteria and Viruses on Elementary Classroom Surfaces and the Potential Role of Classroom Hygiene in the Spread of Infectious Diseases." The Journal of School Nursing. Nov. 10, 2009.
- Bryner, Jeanna. "U.S. money contains highest traces of cocaine." NBC News. Aug. 5, 2008. (July 7, 2013) http://www.nbcnews.com/id/26039953/#.UdoSHyh7P2E
- Castillo, Michelle. "Where do germs flourish in your office? Study reveals dirtiest surfaces." CBC News. May 23, 2012. (July 7, 2013) http://www.cbsnews.com/8334-504763_162-57440032-10391704/where-do-germs-flourish-in-your-office-study-reveals-dirtiest-surfaces/
- Centers for Disease Control and Prevention. "After you touch ducklings or chicks, wash your hands." (July 7, 2013) http://www.cdc.gov/healthypets/resources/salmonella-baby-poultry.pdf
- Chan, Amanda. "Bank Cards, Bills Contaminated With Fecal Bacteria: Study." Huffington Post. Oct. 18, 2012. (July 7, 2013) http://www.huffingtonpost.com/2012/10/18/bank-card-fecal-bacteria-contaminated-germs_n_1971609.html
- Collins, Jeffrey. "Clemson students find bacteria risk in beer pong." The Houston Chronicle. April 15, 2013. (July 7, 2013) http://www.chron.com/life/healthzone/article/Clemson-students-find-bacteria-risk-in-beer-pong-4435071.php
- Dineen, Cari Wira. "The 8 germiest places in the mall. CNN. Nov. 26, 2011. (July 7, 2013) http://www.cnn.com/2011/11/25/health/germiest-places-mall
- Hoyle, Brian. "Pathogens Seem To Be Everywhere - Even in Soap Dispensers." American Society for Microbiology. August 2007. (July 7, 2013) http://forms.asm.org/microbe/index.asp?bid=52087
- Kuria, JK, Wahome RG, Jobalamin M, Kariuki SM. "Profile of bacteria and fungi on money coins." East African Medical Journal. April 2009. (July 7, 2013) http://www.ncbi.nlm.nih.gov/pubmed/20084997
- Roberson, Laura. "4 Surprising Places Germs Hide." April 10, 2012. (July 7, 2013) http://www.menshealth.com/health/call-clean
- Whitcroft, Isla. "The (very) alarming results when one family asked a science lab to test their home for germs." Daily Mail. Aug. 19, 2010. (July 7, 2013) http://www.dailymail.co.uk/health/article-1303403/The-alarming-results-family-asked-science-lab-test-home-germs.html