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The scientist explanation of how he discovered things is superb - in the film version he will be played by Keanu:
http://www.nature.com/nsu/040216/040216-2.html
http://msnbc.msn.com/id/4274188/
American Association for the Advancement of Science,
Seattle, February, 2004
Biohazard lurks in bathrooms
Shower curtains awash with potentially harmful bacteria.
16 February 2004
PETER ALDHOUS
© Image Source
If you don't scrub your shower curtain, you're asking for trouble. These plastic sheets are flooded with bacteria that can cause nasty infections says Norman Pace, a microbiologist at the University of Colorado, Boulder.
Pace has long been interested in the microbial communities that live all around us, and one day decided to examine the soapy film that covered his shower curtain. "I scraped a little bit of soap scum, put it under the microscope and went: 'Wooah!'" he says. The sample teemed with bacterial life.
To find out whether the bugs were harmless or not, Pace enlisted an undergraduate student, Ulrike Theissen. She collected scum from five shower curtains: Pace's own, three more from colleagues at Boulder, and one from Berkeley, California.
The bugs' DNA showed that around 80% belonged to one of two groups: the sphingomonads and the methylobacteria. Both contain species that are opportunistic pathogens, able to infect wounds or sicken people whose immune systems are suppressed. These include the elderly, or those taking drugs to combat the rejection of transplanted organs.
Each time you take a shower you are engulfed by an aerosol of bacteria, Pace told the American Association for the Advancement of Science meeting in Seattle. In most cases, that will not be dangerous. But if you have an unprotected cut, or your immune system is suppressed, it could be a different story.
The bacteria probably feed on volatile organic chemicals shed from human bodies, says Pace, rather than on soap. "When you cough, belch or fart, you're putting a lot of organic chemistry in there," he says. Chemicals called plasticizers, which make shower curtains more flexible, could also feed bacteria, he suggests.
When you cough, belch or fart, you're putting a lot of organic chemistry in there
Norman Pace
University of Colorado
Pace's findings have caused a change in his personal habits: "I take showers, but since the study, I wash my shower curtain every few weeks."
Shower curtains may not be the biggest hazard we encounter while bathing. Other studies have found that the air just above water level in a typical Jacuzzi, or hot tub, is packed with bacteria that can cause lung infections.
"I would not get into a public hot tub. I would not get into a private hot tub, frankly," says Pace.
http://www.nature.com/nsu/040216/040216-2.html
Scientist takes aim at microbial scum
Our bodies do battle with armies of everyday germs
By Paul Recer
Science Writer
The Associated Press
Updated: 05:38 PM PT Feb. 15, 2004
SEATTLE - That soap scum that forms on the shower curtain? It’s really a biofilm loaded with more than a billion bacteria per cubic inch.
The moving belt on an escalator? When you put your hand there, you’re dipping into a puddle of bacteria left by all those who went before.
How about the potting soil for your petunias? It’s the happy home of a pathogen called Microbial Avian Complex, a potentially troublesome bug.
Then there’s the sponge you use to rinse dishes at the sink. Yep, loaded with thriving bacteria.
If this makes you want to go relax in a hot tub, think again. The air wafting from the hot water is probably loaded with microbes, some of them able to give you a hacking cough.
Living in the microbial world
It’s a microbial world, says Norman P. Pace, a researcher at the University of Colorado at Boulder. Virtually everything you touch is coated with the little critters. You couldn’t escape them if you wanted to because your skin is covered with about 100 million bacteria, says Pace.
Yet, science knows very little about environmental microbes, how they live, reproduce and thrive in the natural world. Most of what is known comes from germs cultured and studied in the lab.
“We live in a microbial world and I find it appalling that this is ignored by science,” Pace said Saturday at the national meeting of the American Association for the Advancement of Science.
He discovered the colonies of soap scum bacteria when, out of curiosity, he took a sample from his own shower curtain and examined it under a microscope.
“I was amazed,” he said. Later studies of shower curtains from other homes found the same thing.
“When you step into a shower, you are enmeshed in a bio-aerosol,” he said.
Everyday health risks
Most of the soap scum bacteria is harmless to the healthy. But for people with compromised immune systems, such as patients with AIDS or on chemotherapy or with open wounds, some of the germs can be deadly.
Pace recommends that shower curtains be cleaned weekly.
When he rides an escalator, Pace said he puts down only his knuckles because of the potential broth of bacteria that may be present.
The kitchen sink sponge, he said, “is a spectacular source of bacteria.”
In his own home, he regularly wrings out the sponge and lets it dry, breaking up the wet, warm bacteria paradise.
Pace explored the microbial world of hot tubs after he was asked to investigate why some on the staff at a therapeutic swimming pool were developing “lifeguard lung,” a nagging cough that plagues pool workers.
Studying 'lifeguard lung'
He found that the air above a heated, indoor pool or above a hot tub is enriched with microbe by about 60 percent. Persistent exposure to the air caused the “lifeguard lung” in sensitive people. The same thing can happen around a hot tub.
“These findings are a bit scary. The bottom line is people should be aware of the risk of swimming in indoor pools or sitting in indoor hot tubs,” Pace said.
One hot tub and pool solution, he said, is to increase ventilation so the cloud of microbes is swept away. “Lifeguard lung” generally clears when the exposure is stopped.
But, Pace said, “I wouldn’t get into a public hot tub, or even a private one for that matter.”
No need for extremes
Despite the scary image of bacteria everywhere, Pace said it’s not reasonable to go into a “Howard Hughes mode.” The late billionaire isolated himself and sterilized most things out of fear of germs.
Among microbes there are good guys and bad guys. Many bacteria are beneficial, helping to keep the harmful ones in check. Antibiotics can kill both the useful germs and the bad ones. That gives an advantage to bacteria that are resistant to antibiotics, some of which can be harmful.
Instead, Pace practices prudence.
People should wash their hands frequently, clean off soap scum often, dry out the kitchen sponge and avoid excessive exposure to indoor pools and hot tubs, he said.
Pace said there also needs to be more research about the life and times of microbes in the natural world so science can determine where there is a risk to human health and then develop solutions.
http://msnbc.msn.com/id/4274188/
