Biodesign's Halden in Science spotlight

According to a nationwide EPA survey, the price of keeping our water clean may be the buildup of wastewater sludge filled with contaminants like pharmaceuticals, toxic metals and other compounds. More than half of this sludge is used as fertilizer on U.S. farms each year.

Among the 145 chemicals tested in the EPA study, which was highlighted in a Science magazine news feature, 27 metals, 11 flame retardants, and 12 pharmaceuticals were found in virtually every sample from 74 wastewater treatment plants throughout the country. According to the article, “two of the most common drugs were the antibiotics triclocarban and ciprofloxacin.” Triclocarban is a common additive to antimicrobial soaps and other personal care products. It was found at even higher concentrations than the better-known related antimicrobial agent, triclosan.

Rolf Halden, an environmental engineering expert in the institute’s Center for Environmental Biotechnology who first revealed nationwide contamination with triclocarban in 2005, called the levels of triclocarban measured “astonishingly high.” An unidentified individual at the EPA also judged concentrations that were 10-times greater than those previously reported as looking “intuitively high.” Halden further pointed out the uncertain risks posed to both terrestrial and aquatic life from chemicals in soils and runoff.

Adding to the environmental concerns is work by Halden and colleagues in a 2008 publication (http://www.biodesign.asu.edu/news/anti-bacterial-soap-bad-for-the-environment) that demonstrated that these compounds can persist in aquatic sediments for decades. The impact on humans from environmental exposures has not yet been thoroughly studied, according to Halden’s presentation to the Board on Environmental Studies and Toxicology at the National Academies in December of 2008.

In the next year, EPA expects to complete risk assessments on 10 chemicals in the survey.

To access the Science news article, go to: http://sciencenow.sciencemag.org/cgi/content/full/2009/122/3

To read the EPA report, go to: http://www.epa.gov/waterscience/biosolids/tnsss-overview.html