[Pharmwaste] triclosan article

[Tenace, Laurie]

http://www.nhregister.com/site/news.cfm?newsid=17810050&BRD=1281&PAG=461&dept
_id=566835&rfi=6
Are we playing Russian roulette with bacteria? 
Abram Katz, Register Science Editor
02/05/2007
The American cleanliness craze may come back to haunt us. 


Millions of Americans are slathering antibacterial products on their hands,
unaware that the chemicals are considered unnecessary, are breeding resistant
germs and appear to threaten the environment, experts said.

We're encouraged to spray germ destroyers on "odor-causing bacteria" in
bathrooms and kitchen counters. Everything from soaps to chopsticks to
steering wheels to toys to toothpaste is imbued with these poisons.

Consequently, traces of the chemicals triclosan and tricloban have been
detected in mother's milk and 60 percent of the rivers and streams of the
United States. The persistent chemicals also end up in sludge that is used in
fertilizer to grow the grains and produce we eat.

The effects of these exposures remain unstudied because companies have no
financial incentive to answer the many questions surrounding triclosan and
tricloban, said Rolf U. Halden, assistant professor in the Johns Hopkins
School of Public Health, and co-founder of the Johns Hopkins Center for Water
and Health in the university's Department of Environment and Health Sciences.

"We are finding these chemicals in more and more places where we don't want
them. The presence of triclosan in U.S. breast milk is one example," Halden
said.

"People think these chemicals are inherently safe. They are not fully aware
of potential risks, including environmental pollution issues," he said.

Halden said a study of 62 women revealed that 97 percent had detectable
antibacterial chemicals in their milk.

And it's not as if triclosan or tricloban is a bulwark of public health.

Physicians, environmental health scientists and infectious disease doctors
said that, despite the advertising hype and proliferation of germ-killing
goods of all kinds, simple soap and water is better for home use.

Even most hospitals do not use antibacterial cleaners, preferring
alcohol-based liquids to disinfect hands before and after seeing patients.

At issue are foams, gels, soaps, mouthwashes, kitchen cleanser, dish-washing
detergents and thousands of other consumer goods containing triclosan
(5-chloro-2-(2,4-dichlorophenoxy)phenol) or tricloban
(3-(4-chlorophenyl)-1-(3,4-dichlorphenyl)urea).

This chlorinated duo does kill bacteria, but cannot eradicate micro-organisms
on our hands. Nothing can, because the normal bacterial flora that live on
our skin are not easily removed, said Dr. Louise Dembry, hospital
epidemiologist at Yale-New Haven Hospital.

Dembry said our resident bacteria are beneficial, keeping pathogens out and
producing certain fatty acids and nutrients.

These bacteria are lodged deep in microscopic valleys of skin.
Disease-causing bacteria, such as salmonella, are considered transient and
are more easily removed, she said.

The aim of hand washing is to remove the transient bacteria, or enough of it
so that it cannot cause illness, Dembry said. Soap and water performs this
job well, she said.

"I see no reason to have anti-bacterial soap in my home," Dembry said.

So, while the cleaner may give us a false sense of security, repeated use
eliminates the weak bacteria and enhances strains able to shrug the chemicals
off.

Stuart B. Levy, professor of microbiology at Tufts University and director of
the Center for Adaption Genetics and Drug Resistance in Boston, said that
triclosan and tricloban work by blocking an enzyme, enoyl reductase (ENR),
that bacteria require to build cell walls. While bacteria need the enzyme,
human beings do not. We lack ENR, anyway, which is why we can use the
compounds. 

"Many of us fear that overuse of triclosan could become a contributing factor
to the rise in antibiotic resistance, Levy said.

At the same time, no scientific studies suggest that triclosan reduces the
spread of food-borne illnesses or infectious diseases, said Dr. Robert
Baltimore, Yale professor of pediatrics and epidemiology and a member of the
Committee for Infectious Diseases of the American Academy of Pediatrics.

"I know of no mainstream medical organization that has endorsed these
products," Baltimore said.

The consequences of exposing children to triclosan and tricloban are not
known, Balitmore said. No benefit has been demonstrated either.

Keeping raw foods on different plates before cooking and heating the
ingredients to a sufficiently high temperature, along with cleaning the
kitchen, is sufficient to prevent food poisoning, Baltimore said.

Alcohol-based hand cleaners, which do not have the suspect compounds, are
suited to hospitals because they are convenient, dry rapidly and do not
require soap or water, said Dr. John Shanley, director of infectious diseases
at the University of Connecticut Medical Center.

"In the hospital, hand sanitizers give us a leg up," he said. 

Laurie J. Tenace
Environmental Specialist
Florida Department of Environmental Protection
2600 Blair Stone Road, MS 4555
Tallahassee, Florida 32399-2400
PH: (850) 245-8759
FAX: (850) 245-8811
Laurie.Tenace at dep.state.fl.us 

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