Recently Detected Drinking Water Contaminants: GenX and Other Per‐ and Polyfluoroalkyl Ether Acids

Abstract

For several decades, a common processing aid in the production of fluoropolymers was the ammonium salt of perfluorooctanoic acid (PFOA). Because PFOA is persistent, bioaccumulative, and toxic, its production and use are being phased out in the United States. In 2009, the US Environmental Protection Agency stipulated conditions for the manufacture and commercial use of GenX, a PFOA replacement. While GenX is produced for commercial purposes, the acid form of GenX is also generated as a byproduct during the production of fluoromonomers. The discovery of high concentrations of GenX and related perfluoroalkyl ether acids (PFEAs) in the Cape Fear River and in finished drinking water of more than 200,000 North Carolina residents required quick action by researchers, regulators, public health officials, commercial laboratories, drinking water providers, and consulting engineers. Information about sources and toxicity of GenX as well as an analytical method for the detection of GenX and eight related PFEAs is presented. GenX/PFEA occurrence in water and GenX/PFEA removal by different drinking water treatment processes are also discussed.

Measurement of Novel, Drinking Water-Associated PFAS in Blood from Adults and Children in Wilmington, North Carolina

“…In North Carolina, a 2,150-acre fluorochemical manufacturing facility (i.e., Fayetteville Works) ( Figure 1 ) discharged process wastewater to the Cape Fear River as early as 1980 ( Wagner and Buckland 2017 ). Several poorly understood PFAS, including hexafluoropropylene oxide dimer acid (HFPO-DA or GenX), have been detected in water samples collected downriver of the facility’s effluent discharge point ( Hopkins et al. 2018 ; McCord and Strynar 2019 ; McCord et al.…”

Effect of GenX on P-Glycoprotein, Breast Cancer Resistance Protein, and Multidrug Resistance–Associated Protein 2 at the Blood–Brain Barrier

“…Additional human exposures to GenX occur through contaminated air and food. The current provisional health goal for GenX in North Carolina is 140 ng=L or ∼ 0:4 nM (Hopkins et al 2018), which is four times higher than our lowest effect level in male rats. Based on an acute and chronic aquatic toxicity study, GenX was not toxic and did not bioaccumulate in any of the species tested (Daphnia, trout, carp, and algae) (Hoke et al 2016).…”

“…In the watershed of the Cape River in North Carolina, GenX is a contaminant in finished drinking water and has the capacity to alter important biological signaling pathways (Hopkins et al 2018;Sun et al 2016). In this report, we investigated the effects of GenX on the expression and activity of three important ABC efflux transporters (P-gp, BCRP, and MRP2) of the BBB.…”

Evaluation of Maternal, Embryo, and Placental Effects in CD-1 Mice following Gestational Exposure to Perfluorooctanoic Acid (PFOA) or Hexafluoropropylene Oxide Dimer Acid (HFPO-DA or GenX)

“…GenX has received intense public scrutiny in North Carolina since its discovery in (Strynar et al 2015), and contamination of, the Cape Fear River Basin following release from a manufacturing facility (Sun et al 2016). GenX has also been measured in the environment in other regions of the United States, including the Ohio River (Hopkins et al 2018), as well as in other countries, including the Xiaoqing River in China (Brandsma et al 2018) and the Rhine River in Europe (Heydebreck et al 2015).…”