May 22, 2008

Study Shows Persistent Nature of Antimicrobials

The active ingredients of anti-bacterial soaps and cleaning agents have come under scrutiny by the U.S. Environmental Protection Agency and the U.S. Food and Drug Administration, due to both environmental and human health concerns.
 
Two closely related antimicrobials, triclosan and triclocarban, are at issue. Triclosan (TCS) has a structural resemblance to dioxin, and triclocarban (TCC) is one of the top 10 pharmaceuticals and personal care products most frequently found in the environment and in U.S. drinking water resources.
 
Researcher Rolf Halden and co-workers at the Biodesign Institute at Arizona State University have traced the active ingredients of soaps – used as long ago as the 1960s – to their current location, the shallow sediments of New York City's Jamaica Bay and the Chesapeake Bay, the nation's largest estuary.
 
"Our group has shown that antimicrobial ingredients used a half a century ago, by our parents and grandparents, are still present today at parts-per-million concentrations in estuarine sediments underlying the brackish waters into which New York City and Baltimore discharge their treated domestic wastewater," said Halden, a new member of the institute's Center for Environmental Biotechnology. "This extreme environmental persistence by itself is a concern, and it is only amplified by recent studies that show both triclosan and triclocarban to function as endocrine disruptors in mammalian cell cultures and in animal models."
 
Aiding in his team's research was another type of contamination: the radioactive fallout from nuclear testing conducted in the second half of the last century. Using the known deposition history and half-lives of two radioactive isotopes, cesium-137 and beryllium-7, Halden and his collaborators Steven Chillrud, Jerry Ritchie, and Richard Bopp assigned the approximate time at which sediments observed to contain antimicrobial residues had been deposited in the two East Coast locations.
 
Read more via  eponline.com