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Monday, November 22, 2010

ASU Scientist warns about overuse of germ killing products

Killing microorganisms has become a national obsession. A pair of antimicrobial compounds known as triclosan and triclocarban are the current 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.
According to new research by associate professor Rolf Halden of the Biodesign Institute at Arizona State University, these chemicals are not safe for human health or the environment. And, they do not work.
“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.”
Levels of triclosan in humans have increased by an average of 50 percent since 2004, according to newly updated data from the 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. Also, 97 percent of all U.S. women show detectable levels of triclosan in their breast milk.
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.
 “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.
Halden noted the thresholds for killing microbes are much higher than those for 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 stated.

Dr. Grout’s comment:

The antimicrobial triclosan began its use in the medical surgical arena in 1964. Since then, industry’s drive to convince consumers of the need for antimicrobials has been aggressive and highly effective. Triclosan was first added to commercial liquid hand soap in 1987. Four years later, 76 percent of liquid hand soaps contained the chemical. Triclosan is added to plastic containers, toys and even clothing, too.
In 2005, the FDA asked an expert panel, which included Halden, to review all the available information on these chemicals. The panel concluded that regular use of antimicrobial products by the general public was no more effective against disease causing germs than simply washing thoroughly with regular soap and water.
In 2003 and 2009, University of Minnesota civil engineering professor William Arnold and his colleague Kristopher McNeill published their discovery that triclosan, when exposed to sunlight, generates a specific group of four dioxins – highly toxic compounds that are persistent environmental pollutants. The researchers found that levels of dioxins derived from the antibacterial soap ingredient triclosan have risen by 200 to 300 percent.
Killing microorganisms has become a national obsession. We can stop it by choosing to buy products without “antibacterial” on the label. This is one chemical we can easily do away with by reading labels and just not buying it.

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