Study Finds Bacteria in Unused Paper Towels

Artículo en inglés un estudio encontró bacterias en papel tiene nueve manos.
Recycled Paper Towels Had the Highest Bacterial Counts
ByBrenda Goodman, MA
WebMD Health News
Reviewed byLouise Chang, MD

Dec. 28, 2011 — Grabbing a paper towel in a public restroom may leave more on your hands than you bargained for.
Researchers say they’ve found bacteria, including some that are known to make people sick, in unused paper towels. They also found that those bacteria could be transferred to hands after washing.
The study is published in the American Journal of Infection Control. It did not find any illnesses connected to paper towel use.
Experts say the findings are probably most important for people in hospital isolation units and those with weakened immune function who need to be extra cautious about contact with germs.
Germs Lurk in Paper Towels
Researchers at Laval University in Canada tested six brands of commercial paper towels — the kind doled out in many public bathrooms.
They found bacteria in all of them, but the towels made from recycled fibers were the most heavily contaminated.
“In our study, the concentration of bacteria in the recycled paper was between 100- to 1,000-fold higher than the virgin wood pulp brand,” the researchers write.
Bacterial slime is known to be a problem at recycled paper mills, where it corrodes machines and may damage finished paper sheets.
Researchers say the new paper towel finding fits with other studies that have noted high bacterial counts in other kinds of recycled paper products.
Bacteria may thrive in recycled paper because it contains binding ingredients like starches and fillers that serve as food.
Most of the bacteria found in paper towels were Bacillus bacteria. Many Bacillus strains can produce toxins that cause food poisoning.
One brand of paper towel contained Bacillus cereus bacteria. In addition to food poisoning, B. cereus has been associated with infections of the eyes, lungs, blood, and central nervous system.
Although the found amounts of B. cereus probably wouldn’t harm healthy people, researchers note it may be more dangerous for people who have weakened immune systems, like babies and the elderly, and for people who take medications that suppress their immune function.
Germ experts said the study was an eye-opener.
“These findings are interesting in that we do not think of paper towels as being contaminated,” says Elizabeth Scott, PhD, who is co-director of the Center for Hygiene and Health in Home and Community at Simmons College in Boston.
Scott says the study also made her curious about bacteria in other kinds of paper products.
“It makes me wonder about kitchen towels. These are put to all kinds of uses in direct contact with food, for example, covering and wrapping food,” she says. “And what about facial tissues, which come into close contact with our eyes and noses?”
Advice for Consumers
Scott and other experts note that the study did not find paper towels caused anyone to get sick.
Until more is known, experts agree that this one study shouldn’t be a reason for healthy people to avoid paper towels.
“People shouldn’t think that it’s better not to wash their hands if they only have paper towels available to dry them,” says Angela Golden, DNP, who is president-elect of the American Academy of Nurse Practitioners.
She says 20 seconds with soap and water is still the rule, especially after activities that dramatically increase exposure to germs, like handing raw meat.
Golden says air dryers, if they’re available, may be the healthiest and most environmentally responsible option of all.


Protocolos de investigación – secador Innovaltech

April 3, 2008


Can the process of drying hands that have just been washed actually contaminate them? Is the air discharged from hand dryers cleaner than paper hand towels? The purpose of this study is to determine whether the air discharged from hand dryers is microbiologically contaminated, and to compare this result with that for paper hand towels. The test sites, i.e. public washrooms, were selected so as to represent different situations:
o Restaurants
o Department stores
o Shopping centres

Hand towels vs. dryers
• 90% more bacteria were found on the paper towels than in the hand dryers.
• Paper towels were highly contaminated and could be a major vector of bacteria in food.
• Hand dryers contain up to 95% fewer contaminants than paper towels. Room air vs. air discharged from the hand dryer
• A reduction of up to 74% in yeasts and moulds was observed between the room air and the air discharged from the hand dryer.
• 37% reduction in overall bacteria.
• 40% reduction in yeasts, on average.
• 17% reduction in moulds, on average. Based on these results, the air discharged from hand dryers is cleaner than the room air (the air entering the device).

Dryer model
• There is no significant difference in the results for the various models of hand dryers.

The heated air exiting hand dryers is a natural barrier against microorganisms, i.e. it has a lethal effect that paper towels simply do not have.1 Even if not maintained, hand dryers are still the best choice, by far.

Based on the study results, the following conclusions can be made: • The air discharged from the hand dryers contains fewer microorganisms than the room air.
• The paper towels were moderately to highly contaminated with bacteria, whereas the air from the hand dryers contained significantly fewer of these microorganisms.
• There was no difference observed between the various dryer models.
• As is the case for paper towel dispensers, it was found that hand dryers require periodical maintenance in order to preserve their initial performance level.
• An unmaintained or poorly maintained paper towel dispenser can be a major source and vector of bacteria on hands.


1Hand Dryer and Hygiene, A definitive statement on the bacteriological safety of warm air.

Effects of 4 Hand-Drying Methods for Removing Bacteria From Washed Hands: A Randomized Trial

Artículo en inglés (los efectos de 4 maneras diferentes para secar las manos para eliminar las bacterias)
Objective: To evaluate the effects of 4 different drying methods to remove bacteria from washed hands.
• Subjects and Methods: One hundred adult volunteers par-
ticipated in this randomized prospective study. All bacterial counts were determined using a modified glove-juice sampling procedure. The difference was determined between the amounts of bacteria on hands artificially contaminated with the bacterium Micrococcus luteus before washing with a nonantibacterial soap and after drying by 4 different methods (cloth towels accessed by a rotary dispenser, paper towels from a stack on the hand-washing sink, warm forced air from a mechanical hand-activated dryer, and spontaneous room air evaporation). The re-
sults were analyzed using a nonparametric analysis (the Friedman test). By this method, changes in bacterial colony-forming unit values for each drying method were ranked for each subject.

• Results: The results for 99 subjects were evaluable. No sta-
tistically significant differences were noted in the numbers of colony-forming units for each drying method (P=.72).

• Conclusion: These data demonstrate no statistically signif-
icant differences in the efficiency of 4 different hand-drying methods for removing bacteria from washed hands.

Mayo Clin Proc. 2000;705-708

Hand washing is the single most important procedure in hospital infection control. Many studies reported in the medical literature have shown that disease-causing bacteria are carried on the hands of health care workers. Good hand-washing techniques can prevent the spread of these bacteria to patients. Many studies have also demonstrated the usefulness of antibacterial soaps and the physical washing of the hands to remove bacteria.10-19 Fewer studies have been reported that evaluated the effect that drying the hands has on removing bacteria. The purpose of the present study was to determine the difference between the amount of bacteria on the hand before washing and after drying with 4 different hand-drying methods: cloth towels accessed by a rotary dispenser, paper towels from a stack on the hand-washing sink, warm forced air from a mechanical hand-activated dryer, and spontaneous evaporation. We hypothesized that no significant difference in bacterial reduction occurs among any of these hand-drying methods.


Readers Digest on electric hand dryer in restrooms

Artículo en inglés (el uso de los secadores de mano en los baños)
In public restrooms, paper towel or electric hand dryer?
Far less energy is needed to heat and blow air at your hands than to make paper towels and haul them around.
One study found that nine trees are cut down to supply an average fast-food restaurant with paper towels over a year; the tossed towels then create 1,000 pounds on landfill waste. Reader’s Digest Version: If there’s a choice, go for the hot air.

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