An Associated Press feature on Friday, Filthy Stories
from the Office, noted that computer keyboards, cellphones, the
buttons on office printers and photocopiers, and other office and home
office surfaces harbor "a rank stew of vile bacteria" with "hundreds of
times more bacteria than a toilet seat", citing a statistical metric
that has become a bit of a cliché.
The article references the research of the findings of America's
leading expert on work and home hygiene, Charles Gerba, a professor of
microbiology at the University of Arizona, and other experts in the
field.
A recently posted Apple Knowledge Base article, How to
Disinfect the Apple Internal or External Keyboard, Trackpad, and
Mouse, says:
"In addition to regular cleaning of your computer and
input devices (keyboards, trackpads, and mice), you may find it
necessary to disinfect them.
"Multiple people using the same computer, people using
the computer when they were ill, and the particular environment where
the computer is used, are a few reasons you may wish to disinfect areas
of the computer that people come into contact with the most.
"In order to properly disinfect these areas, you
should use Lysol Wipes, Clorox Disinfecting wipes, or Clorox Kitchen
Disinfecting Wipes . . . when disinfecting your Apple
product."
Several of Dr. Gerba's studies conducted at the University of
Arizona have found that telephones are the most germ-infected objects
in usual environment, followed by desktops, water fountain handles,
microwave door handles, computer keyboards and mice. (Famously, these
studies have found that keyboards generally have 400 times more
bacteria than an average toilet seat.)
Here are the relative germ densities of frequently touched office
equipment cited in the study abstracts:
- Phone: 25,127 germs per square inch
- Desktop surface: 20,961 germs per square inch
- Keyboard: 3,295 germs per square inch
- Mouse: 1,676 germs per square inch
- Fax machine: 301 germs per square inch
- Copy machine: 69 germs per square inch
- Toilet seat: 49 germs per square inch.
The area where you rest your hand on your desk has on average 10
million bacteria, say the researchers.
"For bacteria, a desk is really the laptop of luxury," Dr. Gerba
commented in a press release. "They can feast all day from breakfast to
lunch and even dinner." Gerba and his researchers found that unless
desks were wiped clean with a disinfectant during the day, bacteria
levels climbed higher and higher, peaking after lunch.
The bacteria crawling all over your phone, keyboard, and mouse may
include hundreds of different types, including E. coli, Klebsiella
pneumonia, streptococcus, salmonella, and staphyloccus aureus (a.k.a.
"staph").
But is this something to be concerned about?
IMHO, it's unwise to be too flippant about exposure to potentially
pathogenic germs. Being sick is no fun at all, and exposure to microbes
can make us sick. On the other hand, becoming obsessively paranoid
about it is no doubt counterproductive. Millions of people inhabit
office environments and seem to survive reasonably well, and it's
arguable that some anti-germ countermeasures may actually be playing a
part in making the problem worse - for example, use of antibacterial
agents actually promote the development of antibiotic-resistant
so-called "superbugs."
For example, according to Dean Oliver, a professor of food safety at
the University of California cited in the AP piece, washing your hands
for 20 seconds under soap and running water is preferable to a squirt
of hand sanitizer at your desk, and even though many hand sanitizers
contain anti-microbial chemicals, scrubbing with ordinary soap is
substantially better and doesn't promote bacterial evolution (so long
as it's not antibacterial soap).
Viruses, not bacteria, cause the vast majority of these
ailments.
"Antibacterial soaps would be good if they worked, but they don't
seem to do anything," Dr. Gerba reports. Columbia University
researchers reported in a study, published in the Annals of Internal
Medicine, that families using antibacterial cleaning products
experienced about the same number of runny noses, sore throats, and
fevers as a control group using ordinary soaps and detergents. Viruses,
not bacteria, cause the vast majority of these ailments. However, some
suspect that common antibacterial agents used in cleaning products may
be nurturing the development of antibiotic-resistant microbes.
Staphyloccus aureus is a common bacteria that can cause many
problems from pimples, boils, and cellulitis, a bacterial infection of
the skin, to fatal diseases like pneumonia, meningitis, endocarditis,
and toxic shock syndrome. In one study, Dr. Gerba tested 25 cell phones
and found staph on almost half of them. Cell phones are particularly
virulent germ vectors because they are held close to or touching faces
and lips, get breathed on at close range, held and operated with hands
that may not have been recently washed, and are often stored in warm,
dark pockets in ideal conditions for germ incubation.
Keyboards and mice obviously also get touched continuously and
frequently become contaminated with germ-generating food residues when
users eat at their desks. Microbes get transferred to hands to
keyboards and mice to phones and back again as we move from one device
to another, building up colonies of potentially disease-causing agents
on their vector surfaces. Some disease-causing viruses can survive on
hard surfaces for up to 72 hours.
"We don't think twice about eating at our desks, even though the
average desk has 100 times more bacteria than a kitchen table and 400
times more bacteria than the average toilet," notes Dr. Gerba.
The key to protecting oneself from microbial infections is to
understand vectors - the routes via which disease pathogens enter our
bodies - and it so happens that human/machine interfaces of the
electronic devices that have become ubiquitous tools of everyday life
are also highly efficient disease vectors.
Another expert cited in the AP article, Professor Elizabeth Scott of
the Simmons Center for Hygiene and Health in Boston notes that the
typical office worker touches hands to face an average of 18 times an
hour, essentially transporting the microbial menageries inhabiting
keyboards, cellphones, and whatever else we might have touched since
the last hand-scrub to the thresholds our respiratory and digestive
system every 3-1/2 minutes.
Perhaps even worse, research has shown that while 95% of people say
they wash their hands after using a public bathroom, only 67% actually
do, just 33% of the hand-washers use soap, and only 16% really wash
their hands long enough (long enough being the time it takes to sing a
verse of Happy Birthday or Yankee Doodle without hurrying).
Aside from swabbing tactile
contact surfaces with disinfectants on a regular and frequent basis, a
passive approach is also possible in the form of a growing selection of
antimicrobial phones, keyboards and mice. Most of these new gadgets are
coated with germ-hostile materials based on silver, which you may see
advertised as "nano silver" or "silver ion". Unlike antibiotics, which
some believe also weaken your immune system with frequent exposure,
silver and hydrogen peroxide (which are even more effective when used
in tandem) have not been found to promote the formation of
antibiotic-resistant "superbugs". However, antimicrobial coatings on
products are not without controversy, about which more in a moment.
A century ago, infectious disease was the number one cause of death.
However, Ignaz
Semmelweis's discovery in 1847 that washing hands made a (dramatic)
difference in surgical outcomes (he was more or less drummed out of the
medical profession for his trouble and was eventually committed to a
mental institution, where he died just 14 days later, possibly after
being severely beaten by guards). This led to Louis Pasteur's and
Robert Koch's germ theory of disease, in turn resulting in better
hygiene practices (particularly in medical facilities) in the late 19th
Century, which was a revolutionary developmental step toward the
discovery of antibiotic drugs in the mid-20th Century. By the 1980s,
infectious disease had fallen to being the No. 5 killer, but since then
it has insidiously crept back up to third place, which makes the
sounding of alarm bells about office, cell phone, etc. more than
headline-grabbing FUD.
It may or may not be coincidence that the trend reversal happened
around the same time that personal computers and cell phones became
popular and then near-universal accouterments of contemporary life, but
it is certainly an interesting parallel.
In one study, the University of Arizona's Dr. Gerba and his team
separated office workers into two groups. One group used disinfecting
wipes to clean their desks, phones, and computers once a day while the
other did not. Within two days, the wipes users were found to have a
99.9% reduction in bacteria levels. Among people who did not use wipes,
bacteria levels increased an average of 19-31% on their telephone,
computer mouse, keyboard, and desktop surfaces throughout a typical
workday.
My own favorite agents of disinfection are hydrogen peroxide and
colloidal silver. While proprietary disinfectants like the Lysol and
Clorox products suggested by Apple can certainly do the job, they are
problematical for folks like myself and others who are afflicted with
multiple chemical
sensitivity (MCS). While germs may make me sick, it is 100% certain
that exposure to strongly scented cleaning chemicals will make me sick,
so the cure may be worse than the original problem. Or not, since
non-aromatic alternatives are available.
Both hydrogen peroxide and colloidal silver
work as disinfectants, and both are widely (although not unanimously)
considered reasonably safe as chemicals go for that sort of use. At
standard dilutions, hydrogen peroxide may cause mild skin irritation to
extremely sensitive individuals, but that's about the only caveat with
respect to topical exposure, while colloidal silver, in my experience,
has proved a benign and indeed a wonderful soothing and dealing agent
for burns and skin irritation, but that sort of use is not
uncontroversial.
According to the British Columbia, Canada, Environmental Protection
Department's Water Quality Branch "Silver is a disinfectant for
non-spore forming bacteria at concentrations three or four orders of
magnitude below the levels at which it is toxic to mammalian life
(about 1 gm/day for humans or 500 mg/L in their drinking water)."
That's talking about ingestion - not topical skin exposure. There is a
condition called Agyria that causes a permanent grayish discoloration
of the skin in some individuals who ingest large amounts of
silver over extended periods of time.
United States Patent 6027469, a disinfecting system for hemodialysis
apparatus issued February 22, 2000, notes: "Hydrogen peroxide is used
in hospitals to disinfect surfaces. It is sometimes mixed with
colloidal silver. It is often preferred because it causes far fewer
allergic reactions than alternative disinfectants."
Hydrogen peroxide also has the advantage of being cheap.
For its part, when colloidal silver comes into contact with a germs
like E-coli or staph it essentially smothers the microbe, rendering it
unable to breath or reproduce, effectively stopping it in its
tracks.
As noted above, another avenue of vector interdiction and prevention
has been the use of keyboards, mice, mouse pads, wrist-rests, and even
cellphones that have been coated with antimicrobial agents, either
organic (i.e., either antibiotics; probably not so good for you) or
silver-based.
However, a damper (to say the least) was put on the antimicrobial
input device market last March when the EPA
fined Aten Technology, Inc., of Irvine, CA, peripherals-maker
IOGear's parent company, $208,000 for selling "unregistered pesticides"
and making unproven claims about their effectiveness.
"We're seeing far too many unregistered products that assert
unsubstantiated antimicrobial properties." Katherine
Taylor, associate director of the Communities and Ecosystems
Division in EPA's Pacific Southwest region, is quoted commenting,
"Whether the claim involves use of an existing material such as silver,
or new nano technology, the EPA takes these unverified public health
claims very seriously. Consumers should always follow commonsense
hygiene practices, like washing hands frequently and thoroughly."
There are also potential environmental issues associated with
release of silver nanoparticles into the environment. See Problematic New
Findings Regarding Toxicity of Silver Nanoparticles and Groups File Legal Action
for EPA to Stop Sale of 200+ Nanosilver Products.
A scientific paper, Are Gold and Silver
Nanoparticles Toxic?, by Desma N. Mitchell, Hilary Arnold Godwin,
Elizabeth Claudio is available online.
Note also that there is a distinction between colloidal silver and
nanoparticle silver, which is explained at nano-silver.com.
Some keyboards and mice (but no cellphones that I've heard of) can
also be washed in a dishwasher, which is an effective means of
disinfecting them. I haven't been able to find any Mac specific
washable keyboards.
Some experts recommend washing contact surfaces frequently with an
alcohol-based cleaner, rather than an antibiotic disinfectant, and
blowing out detritus that inevitably finds its way to lodge in the
under-key world from time to time.
As I said, it's not wise to obsess, but it does make good sense to
exercise some cautious prudence in cutting down exposure to
disease-causing organisms. Apple's advice is probably worth following,
especially if you're involved with computers, telephones, and other
tactile-contact devices in a multi-user environment, whether at the
office or at home.
