Joe Caspermeyer, Media Relations Manager & Science Editor
(480) 727-0369 | joseph.caspermeyer@asu.edu
May 16, 2008
Anti-bacterial soap bad for the environment
ASU Biodesign Institute Researcher Rolf Halden studies soap’s effect on environment and impact on human health
The craze over bacteria-killing soaps is likely causing significant harm to the environment and could potentially impact human health, according to ASU Biodesign Institute researcher Rolf Halden, PhD. Halden is a noted expert in determining where in the environment mass-produced chemicals wind up, their impact on health, and how to remove them from drinking water and agricultural soils.
Parental concerns about maintaining germ-free homes for their children have led to an ever-increasing demand for anti-bacterial soaps and cleaning agents. But the active ingredients of these soaps now have come under scrutiny by the EPA and FDA due to both environmental and human health concerns. Recent studies suggest two chemicals commonly used in anti-bacterial soaps—triclosan and triclocarban—disrupt proper endocrine function and pose a health concern.
One major problem is that the chemicals in these soaps do not degrade, but stay around in the environment. "Our group has shown that antimicrobial ingredients used a half a century ago, by our parents and grandparents, are still present today," said Halden, who explained that these chemicals are now more common, particularly now that they are being added to hand soaps. "The irony is that these compounds have no measurable benefit over the use of regular soap and water for hand washing; the contact time simply is too short."
Unfortunately, when the chemicals land in large concentrations in areas where wastewater is discharged and stay there over time, they have ample opportunity to disturb fragile ecosystems. Halden’s group found significant concentrations of harmful soap-related chemicals dating back to the 1950’s in the waters into which New York City and Baltimore discharge their treated domestic wastewater. He notes that the organisms living in this water are "experiencing multi-generational, life-time exposures to our chemical follies."
By analyzing vertical cores of sediment deposited over time in the two sampling locations on the East Coast, Halden’s group showed triclocarban to be present at parts per million levels, which could represent unhealthy levels for aquatic life, especially the bottom feeders that are important to commercial fishing industries like shellfish and crabs. Triclocarban is also now one of today’s top ten pharmaceuticals and personal care products most frequently found in the environment and in U.S. drinking water resources. The impact on humans has not yet been thoroughly studied.
While Halden seeks solutions to cleaning such contaminants from the environment using his engineering expertise, he said the best solution right now in combating the pollution is for consumers to limit the use of antimicrobial personal care products except in situations where they may be necessary, such as clinical environments and around individuals with immune system disorders. Halden is planning to continue his research on persistent antimicrobials by studying their associated health effects in susceptible populations including mothers and their babies.
<>Halden is a recent hire to ASU, formerly with the Johns Hopkins University Bloomberg School of Public Health, where he was an associate professor of Environment Health Sciences and held a joint appointment in Geography and Environmental Engineering. Prior to joining academia, Halden was project engineer at the Lawrence Livermore National Laboratory, where he directed the construction and operation of physical and biological groundwater treatment systems. He received his MS and PhD in civil and environmental engineering from the University of Minnesota, and holds a MS in microbiology from the Technical University of Brunswick, Germany.
“Fate of Triclosan and Evidence for Reductive Dechlorination of Triclocarban in Estuarine Sediments” is an original research paper currently in press in the peer-reviewed journal Environmental Science Technology. The work was funded in part by the Johns Hopkins Center for a Livable Future and the National Institute of Environmental Health Sciences. The study’s authors are T. R. Miller, J. Heidler, S. N. Chillrud, A. DeLaquil, J. C. Ritchie, J. N. Mihalic, R. Bopp, and R. U. Halden.
