Normal Cleanliness (or Dirtyness)

[Guest guest]

What are the mold, bacterial and other cleanliness levels that are

" normal " and usually non-reactive - even for us sensitized people?

The issue comes down to the fact that " presence " of mold is not the

only factor. Other conditions must be present before there is harm to

us. We don't know what those are yet but this means that finding mold

on a sample does not answer the question of whether or not you have a

mold problem that needs to be removed. It would be highly unusual not

to find mold.

For example: A microbiology powerpoint on the Lawrence Berkely Lab

Web site (www.lbl.gov) stated that the number of microbes (bacteria

and mold) in and on the human body is 10 times greater than the total

number of cells in the body. (I saved this and am looking for it).

Also, consider this article from the December 24, 2005, issue of

NewScientist. It is available at www.newscientist.com - but a paid

subscription is needed to read the entire article. So I copied it

below.

Carl Grimes

Healthy Habitats LLC

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How clean is your desk?

24 December 2005

From New Scientist Print Edition.

Hollingham

NEXT time you are bored at work, take a good look at your desk -

computer, screen, piles of paper, assorted clutter, telephone and

three-day-old cup of what was once, in all likelihood, coffee. A

pretty barren and inhospitable place, you might think. But look

closer, your office is teeming with life: from silverfish infesting

forgotten files, to dust mites feasting on showers of dead skin and

cockroaches cleaning up the remains of lunch. They might not keep the

same hours as you but rest assured they're there.

And their presence can have rather unpleasant consequences. " Body

fragments and faeces from insects can be highly allergenic, " warns

Ian Burgess, the director of Insect Research and Development, a

scientific consultancy based in Royston, UK, that specialises in

insect-human relationships. " We've come across lots of people who

suffer skin reactions caused by insect fragments, " he says. The

static charge created by computer monitors can cause thousands of

microscopic allergens to flow through the air, he adds. " The more of

your life you spend in front of the screen, the worse the situation

will be. "

So where do the chief culprits live? Let's begin beneath our feet.

The larvae of the carpet beetle, Anthrenus flavipes, aka " woolly

bears " , are around 3.5 millimetres long and covered in hundreds of

tiny segmented hairs. While the beetle can ruin your rugs, the larvae

can damage your health. The beetles lay their eggs in the carpet. In

autumn they hatch and make their way up the walls. " Because the hairs

of these chubby little larvae are segmented, bits break off and tiny

fragments get into the air, " says Burgess. People who are allergic to

these fragments can get very itchy skin.

Moving up from the ground, there's a riot of activity happening on

the seat of your chair. The warm, possibly moist conditions of the

average office chair make it the perfect home for dust mites. These

globular, hairy arachnids are related to ticks and spiders and live

in close association with humans. Around half a millimetre across,

they feed off dead skin infested with fungi, and although they don't

bite or harm us directly, their faeces contain powerful allergens

that happily make their way into our lungs. Dust mites are widely

accepted as one of the most powerful triggers of asthma.

One study carried out at the UK's Building Research Establishment in

Watford in 1993, and led by Raw, a specialist on indoor air

quality, found that office chairs are commonly infested with dust

mites. The study suggested that when you sit down, a plume of dust

mite faeces belches out from the sides of your chair.

And what about the surface of your desk itself? Though you might dust

and wipe it down on a regular basis, it doesn't take much for nasty

infestations to set in. Dave McLenachan, the Technical Manager for

Rentokil IT Hygiene, based in Manchester, has a cautionary tale for

anyone who thinks their desk is a temple to cleanliness. " We visited

quite a smart office the other day where this person had maggots

crawling out of their keyboard, " he says. Flies had laid their eggs

in the warm moist cracks between the keys. They took little longer

than a weekend to hatch.

Still convinced your hygiene standards are up to scratch? Try this:

turn your keyboard upside down and give it a good shake. Isn't that

an exciting collection of stuff? Dead skin, hair, crumbs, sugar,

possibly worse. All perfect food for flies, maggots, mites,

silverfish.

Equally worrying are the disease carriers. Cockroaches are not only

highly allergenic - their dung and dead scales in particular - but

they come complete with a hoard of pathogens from drains, faeces and

carrion.

Worried? There is worse to come. According to McLenachan it's the

unseen hazards that are the real clincher: fungi and bacteria. The

smaller it gets, he says, the greater the danger.

" There are 400 times more bacteria on a desktop than on a toilet

seat, " says Gerba, professor of microbiology at the

University of Arizona in Tucson. " Offices are worse than public

toilets. " And he should know - he's been studying pathogens in public

restrooms since the mid-1970s. More recently, he's been investigating

the microbes that live in the workplace. " You won't believe some of

the desks I've seen, " he says. " We're spending more time in the

office than ever before and running a germ gauntlet every day at

work. "

Contamination hotspots

Gerba's latest research identifies the most contaminated places in

the office. His team took swabs from similar office work surfaces in

five different US cities: Atlanta in the humid south, Chicago in the

colder north, New York on the east coast, San Francisco on the west

and the dry south-west city of Tucson, Arizona. Samples were taken

from offices, cubicles and conference rooms, and despite the

geographic spread, the results were almost identical. The highest

bacterial counts were on telephone handsets. McLenachan can back this

finding with his own experience. " We recently went to a small

business in Manchester, and there was a guy there who had been off

work for five months with an ear infection. His doctor concluded he

caught it from a telephone. "

Telephone handsets were closely followed by light switches and

computer mice. In conference rooms chair armrests came top of the

list, although the projector remote control was also heavily

contaminated with bacteria.

This in itself is nothing much to worry about. After all, we are all

covered in bacteria. But some bugs are worse for you than others.

Unless you clean your desk, " you can transmit bacteria and the flu

and cold virus around the office, " Gerba warns, " and can very easily

end up with more sick employees. " It's not for nothing that he uses

an alcohol spray and disinfectant wipes on his own desk.

No dirty desk would be complete without the half-full coffee cup, an

ideal breeding ground for furry fungi and bacteria. " Coffee is a

perfect biological substrate, " says Gerba, who uses disposable cups

in his office. " Our study found that in a used coffee cup there are

anywhere between 5000 and 300,000 bacterial cells. " Gerba

concentrated his research on the cups found in communal office

kitchens, most of which, he says, hadn't been cleaned properly and

had crusty brown stains.

The results were disturbing, to say the least. He found that 41 per

cent of the cups contained evidence of faecal contamination, with up

to one in five harbouring Escherichia coli bacteria, a potential

source of food poisoning. He reckons these are likely to have been

spread by " cleaning " with dirty dishcloths. " Funnily enough, the

higher up the administrative chain [the owner was] the more bacteria

there were in the cups. " This he can't explain.

And it's not just bacteria we should be afraid of. " I've seen some

coffee cups that get furry enough to produce airborne spores - that

is a problem for people with allergic asthma, " says Thorne,

professor of toxicology at the University of Iowa College of Public

Health.

The odours from mould growth, apart from being unpleasant, can also

cause problems for asthma sufferers. And Thorne has a word of warning

for anyone who thinks that keeping a plant by their desk improves

their working environment. " Plants, particularly those in wicker

baskets, get wet and mouldy and you get spores released. " Not to

mention pollen. The carpet around the water cooler can also prove a

fertile breeding ground for fungi and bacteria.

Airborne toxins

Thorne's latest study concerned house dust, which is far from the

inert substance you might imagine. His team found bacterial

endotoxins present in all 2500 samples of household dust collected

from beds, sofas and floors in 831 homes across the US. Endotoxins

are released into the air when the cell walls of bacteria rupture or

disintegrate. Once inhaled, these endotoxins can cause inflammation

of the airways. Thorne's research has shown a direct link between the

amounts of dust and the prevalence of asthma symptoms. He doesn't

expect the office to be any different.

But if you think all this means you should stay at home or in the

very least sterilise everything you touch at work, take a leaf out of

Hilton's book. A microbiologist at Aston University in

Birmingham, UK, Hilton has little time for alcohol sprays or

disinfectant wipes around his office, and he certainly doesn't agree

with Gerba when it comes to using disposable coffee cups to protect

against bacterial infection. " The human mouth is full of micro-

organisms, " he says handing me a mug of coffee. " People kiss each

other and don't drop down dead. We've evolved through millions of

years to coexist with microbes - why should we feel the need to kill

all of them when many don't do us any harm? "

Hilton has a point. If this really is a problem, why don't office

workers constantly fall sick with bacterial infections and asthma

attacks? He recently oversaw a study investigating the bacteria that

live on computer keyboards. It looked for evidence of

Enterobacteriaceae - the family of organisms commonly found in the

gut. If they were present that would indicate faecal contamination.

The keyboards in question were located in one of the university's

busy computer labs. Each terminal is used by at least 20 different

students every day.

The researchers took swabs from the " A " and " Z " keys of 120

keyboards. Not surprisingly, they found evidence of more bacteria -

around 150 cells - on the frequently pressed " A " key and only around

30 cells on the less frequently used " Z " . Most of these were likely

to be from skin - Staphylococcus aureus and S. epidermidis, which can

cause skin rash. Only 3 per cent of " A " keys sampled showed

Enterobacteriaceae contamination. Pretty good odds, it would seem, if

you like to suck your thumb at work.

So what steps should we be taking before we brave our workplace? For

Hilton, it's all a question of reasonable precautions: don't assume

everyone else is as hygienic as you, particularly if you are sharing

facilities. " You need to implement a hygiene strategy into your own

life, assuming everyone else is grubby, " he advises. " No matter what

you've been doing, wash your hands before you eat. "

" Don't eat at your desk, " says Thorne. " As well as promoting bacteria

there's also the chance of attracting vermin such as cockroaches,

ants, mice and rats. " He says businesses shouldn't skimp on cleaners

and suggests we could all cut down on clutter. " It's easier to clean

up if you can get to the dust. " But he admits it's easier said than

done. " Looking around my office I can't say I've really followed that

advice. " Even Gerba admits that by Friday his desk is a " disaster " .

In most cases then, the wildlife that lives on and around your desk

is nothing much to worry about. Just beware of the things you share

with co-workers, such as a keyboard, coffee cup or telephone. Thorne

says it's also probably best to approach colleagues with pets or

young children (who play in the dirt more frequently) with caution.

They are more likely to collect endotoxins and allergens on their

clothes at home, not to mention nits, and then bring them into the

office.

Gerba is now trying to work out which type of office is the most

contaminated. His initial findings suggest the worst desks are found

in the media. For asthmatic journalists who work at home this is all

very bad news indeed.

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