EPA finds record PFOS, PFOA levels in Alabama grazing fields
USDA AGRICULTURAL RESEARCH SERVICE
sampling private drinking-water for grazing beef cattle for 12 years, Because of very high levels of perfluwells located much closer to the according to Mitchell. orooctane sulfonate (PFOS), perfluofields. These wells serve fewer than If the chemicals are found to have rooctanoic acid (PFOA), and other 100 people, Mitchell estimates. contaminated meat, the results perfluorochemicals found in agriculEPA officials notified both USDA would mark the first time that pertural soils near Decatur, Ala., scienand FDA about the high levels of fluorochemicals have been traced tists with the U.S. EPA, the U.S. perfluorinated chemicals because the from sludge to commercially proDepartment of Agriculture (USDA), land was used for grazing cattle, duced food. In 2006, perfluorochemiand the U.S. Food and Drug AdminMitchell says. USDA is reistration (FDA) are investisponsible for inspecting raw gating whether meat such as beef or chicken perfluorinated chemicals for potential contamination, have entered the human and FDA oversees processed food chain and contamifoods. But neither USDA nor nated meat. FDA has analyzed any The source of PFOA and samples. PFOS, both of which occur The high concentrations at low part-per-million levof perfluorochemicals in els, is treated municipal sewthe Decatursludge could age sludge, or biosolids, that be a rare situation, or a were applied to some 5000 common onespublished acres of agricultural land, data on the concentrations according to Gail Mitchell, of perfluorinated chemicals EPA Region 4’s deputy direcin sludge are minimal, and tor of water management. Cattle may have picked up PFOA from sludge that was spread on almost nothing is known EPA is still investigating how fields where they graze. about concentrations in soils, the chemicals got into the says Christopher Higgins of sludge, adds Cathy Fehrenthe Colorado School of Mines. cal contamination of two German bacher, chief of EPA’s exposure as“Based on published reports, the rivers was traced to fields treated sessment branch, which is tasked levels in the soil are high compared with sludge (Environ. Sci. Technol. with investigating the fate and transto what one would expect due to 2006, 40, 7108-7109). port of PFOA. normal land application of a purely 3M managed its own industrial Chief among the likely sources are domestic sludge. However, we really wastes, and process wastewater did process wastewater from nearby don’t have enough occurrence data not enter the public system, says Bill manufacturing plants and chemicals to determine whether an industrial Nelson, a 3M spokesperson. Howon consumer products that could source is the reason for the high levever, Daikin America, the other mabreak down to PFOS or PFOA. These els,” he says. jor perfluorochemical manufacturer compounds can enter the sewage It is often difficult to find out how in the area, discharged process system from private homes after much sludge has been applied to a wastewater to the municipal waste washing off goods such as stain-refield, adds soil scientist Murray treatment plant in the past, accordpellent fabrics and coated paper McBride at Cornell University. Being to Marilyn Irving-VanOrden, a products. cause PFOS and PFOA persist indefispokesperson for Daikin. In 2007, a local perfluorochemical nitely in the environment, repeated “Two EPA labs have confirmed manufacturer informed EPA that application of sludge, whose organic these [high levels], but we don’t some of its process wastewater conconstituents eventually break down, know how extensive the contaminatained high levels of perfluorochemicould possibly lead to a concentration is because we are at the start of cals. Samples of municipal sludge tion of perfluorinated chemicals near our investigation,” Mitchell says. Detaken in 2005 by environmental conthe surface, he notes. catur gets its drinking water from the sultants with 3M, a company that In the U.S., the application of bioTennessee River, which is unlikely to produced PFOA in a plant near Desolids to agricultural land is regulated be affected by sludge because the catur, and by EPA in 2006 and 2007, by EPA. Grazing is permitted with no river’s volume is so large, and also show high but variable levels. waiting period after class A biosolids, samples from a smaller, potentially The new soil samples were analyzed which are treated for pathogens, are more vulnerable local drinking-water in October 2008. Decatur water utilapplied. There is a 30-day waiting reservoir are not contaminated by ity records indicate that the sludge period before grazing is allowed after perfluorochemicals. EPA is currently has been applied to grasslands used 10.1021/es803520c
2009 American Chemical Society
Published on Web 12/24/2008
March 1, 2009 / ENVIRONMENTAL SCIENCE & TECHNOLOGY 9 1245
class B biosolids, which must meet less stringent treatment requirements, are applied. Utilities must keep detailed records describing sludge application, but there are no requirements to check for emerging contaminants of concern, such as perfluorochemicals. Several companies manufacture or have manufactured perfluorochemicals in the Decatur area. 3M produced PFOA at its Decatur plant from 1999 to 2000, and PFOA was used by Dyneon LLC, a wholly owned 3M subsidiary, until 2004. In 2004, several Decatur residents who lived near the 3M plant filed suit against
3M, alleging that environmental tests revealed high levels of perfluorinated chemicals in their soil. That same year, EPA officials signed a memorandum of understanding with 3M and Dyneon. The companies agreed to monitor soils on their property and other potential sources of perfluorochemicals. Transfer of perfluorochemicals to grazing animals may well be a significant concern, says McBride, who notes that on pasture lands, sludge spread on top of the field usually is not worked into the soil each time it’s
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applied. “This means that the animals can be ingesting something close to pure sludge,” he says. Grazing cattle ingest from 1 to 18% of their dry-matter intake as soil or sludge, he adds. Worldwide, people have PFOA and PFOS in their blood at low part-per-billion levels. U.S. regulators have not set a federal standard for PFOA. It is still unclear how people are exposed, but food, food packaging, household dust, and drinking water are all likely to contribute (Environ. Sci. Technol. 2007, 41, 4497-4500). —REBECCA RENNER
