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Issue link: http://wateronline.epubxp.com/i/896704
By Greta White T he perfluorinated chemicals (PFCs) contamination crisis in Hoosick Falls, NY stirred the nation. This group of human-made compounds is considered "emerging contaminants" by the U.S. EPA. This means they are chemicals or materials that are characterized by a perceived, potential, or real threat to human health or the environment, a lack of published health standards, the discovery of a new source or pathway to humans, or the development of a new detection method or treatment technology. PFCs are synthetic chemicals predominately utilized in manufacturing, particularly for their lipid- and water-repellent characteristics. They are used in a wide variety of products such as textiles, packaging, and cleaning products and are also additives in coating and plating processes. However, one of their most significant uses has been in firefighting as a compound in aqueous film-forming foam (AFFF). Large quantities of these chemicals have been released over the years and can be found in the air, groundwater, surface water, soil, and sediments. They are chemically and biologically stable in the environment and resist degradation, have low volatility, and are water-soluble; all of these characteristics have led to widespread bioaccumulation, bioconcentration, and long-range transport of PFC compounds. PFCs were brought into the limelight in 1999 when 3M submitted to the EPA information on their potential risks. Over the following years, several environmental hazard/risk assessments were undertaken, leading the EPA to revise and finalize the health advisory levels for perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) from 200 and 400 parts per trillion (ppt), respectively, down to 70 ppt, both individually or in combination, just this year. PFOS and PFOA are two of the most widely used compounds of the hundreds of PFCs and are particularly persistent in the environment and resistant to degradation. In order to develop new health-based regulations, the EPA takes into account a chemical's toxicology, including sources and pathways to receptors, sampling and analysis methods, fate and transport of the compounds, and remediation techniques. While it would appear that regulators have an understanding of these factors, as they have been creating new regulations, significant knowledge gaps remain in the overall understanding of the impacts associated with PFOS and PFOA. What Do We Know? PFOS and PFOA, in particular, have been detected nationwide in blood samples from both humans and wildlife, and the levels reported are significantly higher in areas near PFC production facilities. Exposure pathways include ingestion through food (particularly in fish) and water, product use, and inhalation of PFC-containing particulate matter. These chemicals are being found to accumulate primarily in the serum, liver, and kidneys. Studies on rodents have raised further concerns about developmental, reproductive, and other systemic effects as 8 wateronline.com n Water Innovations PFCs are turning up in source waters and news cycles, drawing both public and regulatory concern. How pervasive is this group of emerging contaminants — namely PFOS and PFOA — and how might the saga unfold for utilities? PFC Contamination: Issues And Answers PFOS and PFOA are two of the most widely used compounds of the hundreds of PFCs and are particularly persistent in the environment and resistant to degradation.