Antimicrobial products ‘toxic for environment, dangerous to human health’

Wednesday, November 10, 2010

WASHINGTON - Antimicrobial products like soaps and handwash may promise to kill germs, but a new study has revealed that they may be causing more harm than good - both for humans and the environment.

A study has indicated that a pair of antimicrobial compounds known as triclosan and triclocarban, which are found in an array of personal care products like antimicrobial soaps, are neither safe for human health and the environment nor they work.

Associate professor Rolf Halden, of the Biodesign Institute at Arizona State University, is interested in chemicals produced in high volume for consumer use.

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).

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.

Halden speculated that these chemicals might in fact persist in the solid byproduct left over after treatment-the sewage sludge.

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.

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. (ANI)

Filed under: Science and Technology

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