The Raelian Movement
for those who are not afraid of the future : http://www.rael.org
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Myth of a Germ-Free World: A Closer Look at Antimicrobial Products
http://www.sciencedaily.com/releases/2010/11/101109152939.htm
ScienceDaily (Nov. 9, 2010) — Killing microorganisms has become a
national obsession. A pair of antimicrobial compounds known as
triclosan and triclocarban are lately the weapons of choice in our war
of attrition against the microbial world. Both chemicals are found in
an array of personal care products like antimicrobial soaps, and
triclosan also is formulated into everyday items ranging from plastics
and toys to articles of clothing.
But are these antimicrobial chemicals, as commonly used by people
across the nation, really safe for human health and the environment?
More pointedly, do they even work? According to associate professor
Rolf Halden, of the Biodesign Institute at Arizona State University,
the answer to these questions is an emphatic "No."
A biologist and engineer, Halden is interested in chemicals produced
in high volume for consumer use. "I follow the pathways of these
substances and try to figure out what they do to the environment, what
they do to us and how we can better manage them."
The antimicrobial triclosan was patented in 1964, and began its use in
clinical settings, where it was found to be a potent bacterial killer,
useful before surgical procedures. Since then, industry's drive to
convince consumers of the need for antimicrobials has been aggressive
and highly effective. Antimicrobials made their first appearance in
commercial hand soaps in the 1980s and by 2001, 76 percent of liquid
hand soaps contained the chemical.
Antimicrobials have become a billion dollar a year industry and these
chemicals now pervade the environment and our bodies. Levels of
triclosan in humans have increased by an average of 50 percent since
2004, according to newly updated data from the Centers for Disease
Control and Prevention (CDC).Triclosan and triclocarban are present in
60 percent of all rivers and streams nationwide and analysis of lake
sediments have shown a steady increase in triclosan since the 1960s.
Antimicrobial chemicals appear in household dust where they may act as
allergens, and alarmingly, 97 percent of all U.S. women show
detectable levels of triclosan in their breast milk. Such unnecessary
exposures carry risks which, at present, are ill-defined.
Halden and his team conducted a series of experiments aimed at
tracking the environmental course of the active ingredients in
personal care products. The disturbing results of their research
indicate that triclosan and triclocarban first aggregate in wastewater
sludge and are transferred to soils and natural water environments,
where they were observed to persist for months or years.
The chemistry behind these compounds, which contain benzene ring
structures that have been chlorinated, make them notoriously difficult
to break down. Further, they are averse to water or hydrophobic,
tending to stick to particles, which decreases their availability for
breakdown processes and facilitates long-range transport in water and
air. A recent study demonstrated the accumulation of triclosan in
dolphins from contaminated coastal waters.
Earlier, the EPA had been provided with industry-funded studies of
wastewater treatment plant effluent, seemingly indicating elimination
of triclosan and triclocarban during the treatment process. But Halden
speculated that these chemicals might in fact persist in the solid
byproduct left over after treatment -- the sewage sludge. The group's
suspicions were confirmed through an initial testing of a large
wastewater treatment plant serving 1.3 million people, located in the
Mid Atlantic region of the U.S.
In the first study of its kind, conducted by the team in 2006, it was
determined that three quarters of the mass of triclocarban entering
the wastewater treatment facility was simply moved from the water into
the sludge. Similar tests confirmed the accumulation of triclosan in
sludge with 50 percent efficiency.
"We make 13 billion pounds of dry sludge per year," Halden notes.
"That is equal to a railroad train filled with sludge stretching 750
miles from Phoenix to San Francisco." One half of this sludge winds up
on agricultural fields. The potential for these chemicals to migrate
into food or leach into groundwater, has not received adequate
consideration. It is likely that antimicrobials are capable of moving
up the food chain, through a process known as biomagnification.
Both triclosan and triclocarban have been linked to endocrine
disruption, with potential adverse impacts on sexual and neurological
development. Further, the accumulation of these antimicrobials in the
environment is exerting selective pressure on microorganisms exposed
to them, thereby increasing the likelihood that a super-bug, resistant
to the very antimicrobials developed to kill them, will emerge -- with
potentially dire consequences for human health.
On the positive side, Halden's team identified specific microorganisms
adapted to not only tolerate but also break down pervasive
antimicrobials. The research is part of a wider effort aimed at
alerting the public and regulatory agencies, including the EPA and
FDA, of the dangers of these chemicals as well as developing effective
remediation strategies.
As Halden explains, "these microbes have the dual advantage of being
resistant to destruction by antimicrobials and being able to break
down these chemicals. You could put them to use for example by adding
them to high-strength industrial wastewater before it gets combined
with the domestic sewage."
In the group's recent studies, appearing in Water Research and the
Journal of Hazardous Materials, levels of triclosan and triclocarban
were measured, to determine the degree to which these chemicals, along
with other antimicrobials, become concentrated in sludge, and what
happens to them thereafter. Triclosan and triclocarban account for
two-thirds of the mass of all the antimicrobials in sludge, Halden
found, based on a survey of 72 chemicals entering the wastewater
treatment stream. Further, massive bioaccumulation of antimicrobial
chemicals has been observed in various species. Earthworms exposed to
triclosan, for example, showed accumulation of the chemical by a
factor of 2700 percent.
Halden notes the impact these persistent chemicals can have on other
life forms in the environment that are not their intended target. The
thresholds for killing microbes are much higher than those for other,
more fragile life forms, like algae, crustaceans and fish. "This
explains why residual concentrations of antimicrobials found in
aquatic environments are still sufficiently harmful to wipe out the
small and sensitive crustaceans, which are critical to the aquatic
life cycle and food web," Halden says.
For certain, chemicals like triclosan and triclocarban have their
place in public health, particularly in clinical settings, among
people who are trained in their proper use. However, in 2005, the FDA
put together an expert panel to review all the available information
on these chemicals. Halden was among the voting members of this
committee, which concluded that regular use of antimicrobial products
by the general public was no more effective than traditional methods
of proper hygiene -- simply washing thoroughly with regular soap and
water.
Society, Halden insists, is participating in a grand experiment in
which we are all guinea pigs. While effective regulation of these
chemicals is badly needed, Halden says that the inertia of regulatory
agencies is a formidable obstacle. In the meantime, the best hope is
for consumers to avoid triclosan and triclocarban containing products.
"The culture of fear leads people to make impulsive decisions and buy
a lot of antimicrobial products that are not really needed," Halden
says. "It's a profitable market to be in, but not one that is
ultimately sustainable or a good idea."
Editor's Note: This article is not intended to provide medical advice,
diagnosis or treatment.
Story Source:
The above story is reprinted (with editorial adaptations by
ScienceDaily staff) from materials provided by Arizona State
University. The original article was written by Richard Harth, science
writer, Biodesign Institute at ASU.
Journal References:
1. Todd R. Miller, David R. Colquhoun, Rolf U. Halden.
Identification of wastewater bacteria involved in the degradation of
triclocarban and its non-chlorinated congener. Journal of Hazardous
Materials, 2010; 183 (1-3): 766 DOI: 10.1016/j.jhazmat.2010.07.092
2. Evelyn Walters, Kristin McClellan, Rolf U. Halden. Occurrence
and loss over three years of 72 pharmaceuticals and personal care
products from biosolids–soil mixtures in outdoor mesocosms. Water
Research, 2010; DOI: 10.1016/j.watres.2010.07.051
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"Ethics" is simply a last-gasp attempt by deist conservatives and
orthodox dogmatics to keep humanity in ignorance and obscurantism,
through the well tried fermentation of fear, the fear of science and
new technologies.
There is nothing glorious about what our ancestors call history,
it is simply a succession of mistakes, intolerances and violations.
On the contrary, let us embrace Science and the new technologies
unfettered, for it is these which will liberate mankind from the
myth of god, and free us from our age old fears, from disease,
death and the sweat of labour.
Rael
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