Novel Perfluoroalkyl Ether Carboxylic Acids (PFECAs) and Sulfonic Acids (PFESAs): Occurrence and Association with Serum Biochemical Parameters in Residents Living Near a Fluorochemical Plant in China

Abstract

Although perfluoroalkyl ether carboxylic (PFECAs) and sulfonic acids (PFESAs) have been widely detected in environmental matrices, their occurrence in humans and impact on human health remains insufficiently understood. Here, we report on 13 PFECAs and PFESAs in 977 sera samples collected from residents living near a fluorochemical plant in Shandong, China. The sum concentration of these emerging PFECAs accounted for 13% of the total PFASs in the serum of the participants, with the frequent detection of several PFECAs (>95%) (PFMOAA, PFO4DA, and PFO5DoDA at median concentrations of 12.91, 0.142, and 0.987 ng/mL, respectively) and PFESAs (98.7%) (Nafion byproduct 2 at a median concentration of 0.097 ng/mL). Serum PFMOAA, PFO5DoDA, and 6:2 Cl-PFESA levels were significantly higher in males than in females. Positive relationships were observed between age and PFMOAA, 6:2 Cl-PFESA, and H-PFMO2OSA levels, whereas HFPO-TA and PFO5DoDA serum concentrations in the 0–40-year age group were lower than that in the >40-year age group. Furthermore, multivariate linear regression models and sensitivity analyses showed positive associations among PFO5DoDA levels, elevated lipid parameters (cholesterol, low-density lipoprotein cholesterol, and triglycerides), liver function markers (albumin levels and alanine transaminase, aspartate aminotransferase, and glutamyl transpeptidase activities), and uric acid levels. Thus, our results suggest potential health risks from exposure to novel PFESAs and PFECAs (especially PFO5DoDA).

Occurrence of Novel Perfluoroalkyl Ether Carboxylic Acids in River Water and Human Urine Quantified by a Simple Liquid–Liquid Microextraction Approach Coupled with LC–MS/MS

“…Native standards of six emerging PFECAs, i.e., PFMOAA, PFO2HxA, PFO3OA, PFO4DA, PFO5DoDA, HFPO-TrA, and HFPO-TeA, were synthesized from their corresponding ethyl esters (Sanming Hexafluo Chemical Co., Ltd., China) following previously reported reactions. 17 Four PFECAs (i.e., HFPO-DA, PF4OPeA, PF5OHxA, PFO2HpA) were purchased from Wellington Laboratories (Guelph, ON, Canada). More details on standards and reagents are listed in Text S1.…”

“…Source temperature and ion-spray voltage can greatly impact the insource fragmentation of PFECAs. 17 Therefore, optimal conditions were screened from 12 × 15 combinations with 50 °C increments for the source temperature (50−600 °C) and 250 V increments for the voltage (1000−4500 V). When in-source fragmentation of PFECAs was effectively reduced under optimum conditions, an earlier strategy using secondary fragments (e.g., [M−H−CO 2 ] − and [M−H−CF 2 CO 2 ] − ) as "parent ions" was no longer needed 10,14,16 as sufficient signal strength could be obtained for [M−H] − ions.…”

“…Some of these PFECAs are found at comparable or even greater levels than historical PFASs in field studies downstream of fluorochemical plants. 4,13−15 Long-chain homologues have been detected in human sera, 4,16,17 and their levels are significantly associated with lipid and liver function biomarkers. 17 Evidence also suggests that the hepatotoxicity 18 and developmental toxicity 19 of these long-chain PFECAs may be more serious than those of PFOA.…”

“…In the past five years, the use of liquid chromatography-high-resolution mass spectrometry (LC-HRMS) has identified various new PFECAs, with single or multiple ether linkages, branch chains, and heteroatoms dispersed in their backbones. − Two important series of emerging PFECAs are frequently reported, i.e., hexafluoropropylene oxide (HFPO) homologues, which oligomerized by two or more HFPO monomers, and OCF 2 -type homologues featuring a mono- or multi-OCF 2 moiety (Figure S1). Some of these PFECAs are found at comparable or even greater levels than historical PFASs in field studies downstream of fluorochemical plants. ,− Long-chain homologues have been detected in human sera, ,, and their levels are significantly associated with lipid and liver function biomarkers . Evidence also suggests that the hepatotoxicity and developmental toxicity of these long-chain PFECAs may be more serious than those of PFOA.…”

Degradation Pathways and Complete Defluorination of Chlorinated Polyfluoroalkyl Substances (Clx−PFAS)

“…15,16 However, "alternative" PFAS containing −O−, [17][18][19] -H, 20,21 and -Cl 22,23 in the fluorinated moiety (RF) have also been systematically developed and extensively applied for decades. Recent studies have confirmed their negative health effects [24][25][26][27] and worldwide pollution in water [28][29][30][31][32][33][34][35][36] and soil. 37 Chlorine-containing PFAS (Clx−PFAS) are prepared by the telomerization process, where the iodinated telogen (RF−I) initiates the polymerization of fluorinated olefins (Schemes 1A and B).…”