states, according to data compiled by Clean Water Action, an environmental advocacy group. A recent Minnesota survey found manufacturers, 3M and Daikin Scientists are scrambling to get a elevated levels of several perfluoroAmerica, Inc., and one user, Toray handle on the levels of perfluorochemicals were found at some Fluorofibers America, Inc., have chemicals in treated municipal plants, particularly those in urban submitted monitoring data indisewage sludge as further details areas. In many cases, a specific cating they might be possible emerge about the unexpected dissource is not apparent, according sources. Toray Fluorofibers covery of these compounds in to Marvin Hora of the Minnesota America spokesman Arthur Nelfields near Decatur, Ala. Pollution Control Agency. “The levson says, “Any emissions we In October 2008, U.S. EPA scienels vary, but these seem to tists found near Decatur be universal chemicals that some of the highest conare showing up everycentrations of perfluoroocwhere,” Hora adds. tane sulfonate (PFOS), Finding perfluorochemiperfluorooctanoic acid cals in municipal sludge is (PFOA), other carboxylic not surprising given the acids, and fluorotelomer large number of potential alcohols in U.S. soils and precursors that are used traced the source back to commercially, says Univeritreated municipal sewage ty of Toronto chemist Scott sludge, or biosolids. In Mabury. “We have found April 2009, EPA tested wells diPAPs, polyfluoroalkyl and ponds in the areas phosphoric acid diesters where the biosolids were that are used as food conspread. Out of 51 samples, tact paper chemicals, in 25% exceeded the agency’s Biosolids are rich in plant nutrients, but they may also be a municipal sludge at levels recently developed shortover 100 times higher than term provisional health ad- source of perfluorochemicals. corresponding perfluorovisory limit of 0.4 carboxylic acids. Since they are have would be as a result of our micrograms per liter for PFOA. All readily metabolized to perfluorouse of polytetrafluoroethylene concentrations of PFOS were below carboxylic acids, it is likely they will dispersions, which are compliant the 0.2 micrograms-per-liter publiccontribute significantly to the enviwith the EPA PFOA Stewardship health advisory limit. Other carboronmental burden of these chemiprogram.” Previously, 3M told xylic acids occurred in more than cals,” he says. ES&T that it treats all process half of the water samples. A recent EPA survey of contamiwastewater in-house but sends “The findings here have genernants in sludge did not measure the wastewater from bathrooms ated [EPA] Office of Water interperfluorochemicals. “When the and similar uses to the municiest,” according to Gail Mitchell, study started, we didn’t have a pal system. Daikin told ES&T EPA Region 4’s deputy director method,” says Rudzinki. “We won’t previously that process wastewaof water management. “They are be able to analyze those samples ter had been discharged to the evaluating what it means to the now because they are stored in municipal system in the past. biosolids program and trying to Teflon containers,” she adds. The other companies, mainly decide what the next step PFOS was recently added to the metal platers, did not have any should be,” she adds. list of internationally banned or monitoring data, Mitchell says. There are still many unknowns, restricted persistent organic pollutAnother possible source is landfill says Suzanne Rudzinski at the Ofants targeted by the Stockholm leachate, which is also sent to the fice of Water. “Right now, we Convention. However, exemptions wastewater treatment plant. In don’t have representative data on include its use in coatings for semigeneral, scientists have collected perfluorochemicals in biosolids. conductors, firefighting foam, and little data about the concentraWe need more science and more medical devices, and countries can tions of perfluorinated chemicals data.” ask for specific exemptions for in sludge and almost none about EPA is still looking for sources of some other commercial uses. concentrations in soil, according the perfluorochemicals. The agency to Christopher Higgins of the requested information from 14 lo—REBECCA RENNER Colorado School of Mines. Perfluocal industries including manufacrochemical contamination has turers and major users, according been found in seven eastern to Mitchell. Two perfluorochemical DANA W. KOLPIN, U.S. GEOLOGICAL SURVEY
Are perfluorochemicals widespread in biosolids?
5164 9 ENVIRONMENTAL SCIENCE & TECHNOLOGY / July 15, 2009
10.1021/es901417h
2009 American Chemical Society
Published on Web 06/03/2009
