Monday, March 03, 2008

WATER, fluid more precious than oil

WATER, fluid more precious than oil
Chemically, water is a nearly universal solvent. Biologically, it is the dominant constituent of living matter. Physically, it is virtually the only common substance that occurs on our planet as gas, liquid and solid and so defines many of the characteristics of our world. A view of Earth’s surface from outer space is not earthen at all but watery.
Yet finding enough water is a difficult and divisive problem for our society. Most of us take water for granted until nature reminds us otherwise. The latest reminder was the delayed onset of the rains in mid-2007 in the northern Philippines that created such anxiety and panic that officials scrambled some planes skyward to cloud-seed salt. It abated the fears but produced little moisture. Nature, in this instance in the form of the seasonal Southwest Monsoon withheld the rain bearing clouds.
A water shortage is a frustrating problem. Decades of cloud-seeding studies in dry locations around the globe have only confirmed that there is very little meteorologists can do when nature stubbornly withholds rain. Those Air Force planes scattering dry ice or silver iodide calms public anxiety but little moisture to wet the earth. Engineers build dams to collect water or levees to contain overflowing river banks but can’t make one drop of water grow into two.
Water sustains life, not only to the human species but also other organisms that cause illness to humans. Water borne diseases, most commonly diarrhea and typhoid, are caused by water contaminated accidentally or by carelessness. Circulating in nature’s hydrologic cycle (cloud-rain-surface or ground water) the fluid is abiotic but is compromised by man-made devices or pollution.


Clean water plays another role in human health: hygiene.
Q & A:Men are supposed to wash their hands after urination?
A Harvard man and a Yale man are at the urinal. They finish, zip up, then the Harvard man proceeds to the sink to wash his hands, while the Yale man immediately makes for the exit. The Harvard man says, "At Hah-vahd they teach us to wash our hands after we urinate."
The Yale man replies, "At Yale they teach us not to piss on our hands."
Question: why is it customary for males to wash their hands after urination? I bathe daily and wear fresh underpants, so how does my penis get dirty? It's not like I dig a ditch with it. However, my hands might get dirty from daily activities. Is it not more sensible then to wash my hands before touching my clean penis? Is post urination hand washing a throwback to the bad old days, when sex was "dirty" and so, by extension, were sex organs?
Answer: Good joke; common (but stupid) attitude; rank (but important) topic. Some facts:
The purpose of washing is not to get pee off your hands.
No amount of washing will make you clean.
Your boxer-shorts region--from belly button to mid-thigh--is crawling with germs known as coliform bacteria. These bacteria originated in your intestine, and some of them are deadly. Recall the punji stakes, sharpened sticks that the Vietcong concealed point up along trails and daubed with excrement. Stepping on one, you had a good chance of contracting a fatal infection. Similarly, an otherwise not-so-serious gunshot or knife injury could kill you if it perforated the intestine and allowed coliform bacteria to spread around your abdomen.
What you may not know is that washing will not make the coliform bacteria go away. They're holed up in the pores of your skin and nothing short of sandblasting--certainly not your morning shower--is going to get them out. Showering merely gets rid of the ones that have strayed onto the surface. The bacteria won't do much harm if they stay put, but when you urinate your fingers come in contact with Mister P. long enough for the coliform bacteria in your pores to hop aboard. Your fingers subsequently touch lots of other infectible items. If you don't wash your hands with soap and water (soap gets rid of the skin oil that the bacteria stick to). . .
It now dawns on you: jeez, if merely touching my privates is enough to transmit bacteria, it doesn't matter if I pee or not! Urine is actually fairly sterile. There are reports of it being used during wartime in poor countries as a sort of battlefield disinfectant. The lesson to draw from this, however, is not that you can go forth dripping, but rather that just because you didn't pee on your fingers doesn't mean you can skip washing up.

Washing Hands Best

The largest, most comprehensive study ever done comparing the effectiveness of hand hygiene products shows that nothing works better in getting rid of disease-causing viruses than simply washing one’s hands with good old-fashioned soap and water.
Among the viruses soapy hand washing flushes down the drain is the one that causes the common cold. Other removable viruses cause hepatitis A, acute gastroenteritis and a host of other illnesses. A separate key finding was that waterless handwipes only removed roughly 50 percent of bacteria from volunteer subjects’ hands.

"We studied the efficacy of 14 different hand hygiene agents in reducing bacteria and viruses from the hands. No other studies have measured the effectiveness in removing both bacteria and viruses at the same time." said a public health epidemiologist with the University of North Carolina Health Care System and the UNC School of Public Health.

For the first time, too, the UNC researchers tested what happened when people cleaned their hands for only 10 seconds. That represented the average length of time researchers observed busy health-care personnel washing or otherwise disinfecting their hands at work. Previous studies have had people clean their hands for 30 seconds or so, but that’s not what health-care workers usually do in practice, and the study wanted to test the products under realistic conditions.

Anti-microbial agents were best at reducing bacteria on hands, but waterless, alcohol-based agents had variable and sometimes poor effects, becoming less effective after multiple washes. For removing viruses from the hands, physical removal with soap and water was most effective since some viruses are hardy and relatively resistant to disinfection.

A report on the findings appears in the March issue of the American Journal of Infection Control. Authors are professors of medicine and epidemiology at the UNC schools of medicine and public health; a professor of environmental sciences and engineering in public health; and medical technologist. A Duke University biostatistician, helped analyze the data.

"These findings are important because health-care associated infections rank in the top five causes of death, with an estimated 90,000 deaths each year in the United States," the author said. "Hand hygiene agents have been shown to reduce the incidence of health-care associated infections, and a variety of hand hygiene agents are now available with different active ingredients and application methods.

"Our study showed that the anti-microbial hand washing agents were significantly more effective in reducing bacteria than the alcohol-based handrubs and waterless handwipes," he said. "Our study also showed that, at a short exposure time of 10 seconds, all agents with the exception of handwipes demonstrated a 90 percent reduction of bacteria on the hands."

Alcohol-based handrubs were generally ineffective in demonstrating a significant reduction of a relatively resistant virus. While the use of alcohol-based handrubs will continue to be an important infection control measure, it is important to recommend or require traditional hand washing with soap and water throughout each day.

Researchers first had volunteers clean their hands and then contaminated their hands with Serratia marcescens, a harmless bacterium, and MS2 bacteriophage, a virus comparable to, and substituted for, disease-causing organisms. After that, scientists had the subjects clean their hands with various agents and measured how much of the bacteria and virus remained afterwards.

Adapted from materials from University Of North Carolina School Of Medicine.

Related Stories

Hand Sanitizers No Substitute For Soap And Water (Feb. 21, 2000) — Instant hand sanitizers may not be everything consumers expect, according to a Purdue university professor who teaches sanitation practices for food service ... > read more
Simple Measures Can Reduce Spread Of Respiratory Viruses (Oct. 18, 2007) — Blocking transmission of respiratory viruses is an important part of halting spread of disease if an epidemic breaks out. Good hand-washing with normal soap and water are effective ways of containing ... > read more
When It Comes Fighting To C. Difficile, Try Soap And Warm Water (Sep. 25, 2007) — Hospitals world-wide battle infections on a daily basis. One of the most difficult bacteria to combat is Clostridium difficile. Researchers check out many control methods and gave the highest honors ... > read more
New Technology Creates "Super Soap" (May 21, 2002) — Scientists have developed innovative soap technology that significantly reduces the attachment of bacteria to the skin. They report their findings today at the 102nd General Meeting of the American ... > read more
If You Don't Want To Fall Ill This Christmas, Then Share A Festive Kiss But Don't Shake Hands (Dec. 19, 2007) — We've all heard people say 'I won't kiss you, I've got a cold'. But a new report warns that we may be far more at risk of passing on an infection by shaking someone's hand than in sharing a ... > read more
At Home
Most studies on hand washing focus on medical and food service workers. But the American Journal of Infection Control focuses on washing hands at home as a way to stop infections from spreading. Several studies show hands are the single most important transmission route for all types of infections.
Even though most people know to wash their hands after using the toilet or handling a diaper, studies suggest many people are still ending up with germs, particularly those spread by feces, on their hands after leaving the bathroom or caring for a baby.
One study looked in homes of infants recently vaccinated against polio. After vaccination, the virus is known to shed in the baby’s feces. Researchers found the virus on 13 percent of bathroom, living room and kitchen surfaces. While the virus from the vaccine didn’t pose a health risk, the study shows how feces-borne viruses can travel through the home.
Another study found that in homes where salmonella cases had been diagnosed, the bacteria were still lurking in toilet bowls three weeks after the outbreak. Water splashing on the toilet seat was a source of contamination.
Doorknobs, bathroom faucets and toilet flush handles are key sources of germ transmission in the home. That’s why people should focus on cleaning such surfaces regularly and always wash hands after touching them. In one study, a volunteer touched a door handle that had been contaminated with a virus. He then shook hands with other volunteers, and further tests showed he had spread the virus to six people.
The study authors note that the timing of hand washing is key. It’s obvious to wash hands after using the toilet, after sneezing or before eating or handling food. Other crucial times for hand washing are after changing a diaper or cleaning up after a pet, or after touching garbage cans, cleaning cloths, cutting boards, dish rags and utensils that may have come into contact with raw food.
While it may be hard to believe that something as simple as regular hand washing can make a difference in your family’s health, consider what happened in Hong Kong during a 2003 outbreak of SARS, a severe and potentially deadly form of viral pneumonia. The outbreak triggered extensive public and community health measures promoting basic hygiene, including regular hand washing. Not only was the SARS outbreak contained, but other cases of respiratory illnesses, including the flu, dropped sharply.
Sound advice. I would add that we should avoid touching our mouth, nose, and eyes with unwashed hands. If you can’t wash your hands, use a tissue, and make sure the part that touched your hands does not touch your face. — Posted by Jack F. Bukowski, MD, PhD
I would like an answer to the paper towels vs. electric hand dryer controversy. Restrooms with hand dryers all have signs proclaiming that they are the best hygienic choice. However, restrooms with paper towels often have signs explaining how one should first turn off the sink faucets with the towels and then dry the hands. Actually, this makes more sense to me, especially if one also exits the room using the paper towel to open the door. — Posted by Michael Hendler
It is important to emphasize the obvious. Washing hands, beware of toilet handles, door knobs, etc. all apply to every situation outside the home as well. Public restrooms of all sorts, and most particularly in airplanes, the most dangerous place to be in terms of danger of infection (after hospitals , of course). — Posted by Richard Gustafson
I used to work in an office with about twenty other people. One of my co-workers commented on my use of a paper towel to open the bathroom door, teasing me about ‘not trusting’ my co-workers to wash their hands. I just smiled and said, “It’s habit, especially during flu season.” Yes, flu germs are often airborne, but people don’t wash their hands after they blow their noses, cough, or sneeze, and they leave those germs on everything they touch. — Posted by Rowan
… people who sneeze into their hands. I’ve seen many many people who would otherwise consider themselves to be extreme hygienic do this in public - and then proceed to touch everything around them as if nothing has happened. If you don’t have a tissue, spare the rest of us and sneeze into your shirt or jacket sleeve, not your hands! — Posted by Dan Schenck
How to wash one’s hands properly is also very important. In the public washrooms we’re having increasing installation of automatic water taps, soap dispensers using sensors. This is good. However, the provision of air blowers for hands drying means paper towels no longer provided. Users have to find way to pull open the exit door. Perhaps consideration should be given to provision of automatic exit door or simply taking it down if circumstances allow.— Posted by Kevin Shum
Does anyone know the difference in effectiveness in reducing transmission with antibacterial soaps vs. regular soaps? Like my hesitation to use antibiotics quickly, I’ve assumed antibacterial soaps will encourage the presence of more resistant bacterial and thus have avoided using them — but I’d love to know more from any experts on the subject.

From TPP — I’ve written about this topic. there is no difference in effectiveness between handwashing with regular soap or antibacterial soap, although there is a theoretical risk of contributing to bacteria resistance when you use an antibacterial soap product. (The article is reproduced below.)
Germ Fighters May Lead to Hardier Germs
By TARA PARKER-POPE Published: October 30, 2007
Reports of schoolchildren dying from infections with drug-resistant bacteria are enough to send parents on an antimicrobial cleaning frenzy.
But before you start waging your own personal war on single-celled organisms, be warned. Many household and personal cleaners contain ingredients that could make the resistance problem worse.
Today, hundreds of soaps, hand lotions, kitchen cleansers and even toothpastes and mouthwashes include antibacterial agents. One of the most popular is triclosan, which has been used not only in cleaners but also to coat toys, cutting boards, mouse pads, wallpaper and even dog bowls.
The temptation to blanket our families with antibacterial protection has been fueled by scary news reports about a deadly bacteria called CA-MRSA, which stands for community-acquired methicillin-resistant Staphylococcus aureus. Two otherwise healthy children — a seventh grader in Brooklyn and a high school football player in Virginia — died in recent weeks from MRSA infections.
The general advice for avoiding infection is basic hygiene — washing hands or using alcohol-based sanitizers, keeping scrapes covered until healed and refraining from sharing personal items like towels and cosmetics.
But some recent laboratory studies suggest that antibacterial products containing triclosan may not be the best way to stay clean. Instead of wiping out bacteria randomly, the way regular soap or alcohol-based products do, triclosan may inhibit the growth of bacteria in a way that leaves a larger proportion of resistant bacteria behind, according to lab studies at Tufts and Colorado State Universities, among others.
In fairness, none of the research has shown this effect in the real world. In fact, two randomized studies comparing people who used triclosan hand soaps with people who used plain soaps found no evidence that triclosan contributed to bacteria resistance. The soap industry says these results are far more compelling than the controlled lab studies.
But Allison E. Aiello, an assistant professor of epidemiology at the University of Michigan School of Public Health, says the laboratory evidence against triclosan is compelling enough to raise questions about the products. More meaningful, she says, is that several studies show that antibacterial soaps sold to consumers are no better than plain soaps in terms of reducing illness or the count of bacteria left on hands.
“Given that there doesn’t seem to be a benefit, I think it warrants further evaluation,” said Dr. Aiello, whose review article on antibacterial soaps was published last month in the medical journal Clinical Infectious Diseases. “We should be questioning use of these products.”
Soap companies say the worry about triclosan takes the focus away from the real culprit: the abuse of antibiotics and the need for better hygiene in general. “The last thing we want to see is people discouraged from using beneficial hygiene products,” said Brian Sansoni, a spokesman for the Soap and Detergent Association.
In any given colony of bacteria, some portion will often have a natural resistance to antibiotics. The resistant germs might contain genetic variants that give them stronger cell walls, or pumps that allow them to spit the antibiotic back out. They survive the antibiotic onslaught, and with the susceptible bacteria out of the way, naturally resistant strains can thrive. Not only do they multiply, but some can also share their resistance with other bacteria and collect new resistance traits over time.
Natural resistance happens on such a small scale that it is generally not a health worry. But when antibiotics are overused — either by individuals or when farmers add them to animal feed — the effect is amplified. “You’re going to have this exaggerated, snowballing effect of resistant bacteria multiplying all around you,” said Marlene Zuk, a biology professor at the University of California, Riverside, whose book “Riddled With Life” discusses the proliferation of antibacterial cleaners and personal products.
The question about cleaners containing triclosan is whether the agent kills germs randomly or whether it promotes the same selection pressures that can lead to antibiotic resistance. The worry is not that bacteria might become resistant to triclosan. The fear is that the same bacteria that resist triclosan can also resist certain antibiotics. And a handful of lab studies have suggested that triclosan may select for resistant bacteria.
“Here you have a substance that has been widely used in hospital settings and household settings,” said Herbert P. Schweizer, associate director for research at the department of microbiology, immunology and pathology at Colorado State University, who conducted some of the lab studies showing triclosan resistance. “The exposure to this widely used antimicrobial caused emergence of multidrug resistance in laboratory strains.”
That studies of triclosan use haven’t shown a resistance problem in the community doesn’t mean it won’t happen, said Dr. Stuart B. Levy, a microbiology professor at Tufts who is president of the Alliance for Prudent Use of Antibiotics.
“I’m the first to say we haven’t seen a difference yet in the home,” Dr. Levy said. “We know from antibiotic data that if it happens in a lab it will eventually happen outside the lab.”

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