Search

Various per- and polyfluoroalkyl substances (PFASs) remain undiscovered and unexplored in the environment. The goals of this study were to discover new species of PFASs in effluent and surface waters from a fluorochemical industrial zone, and to assess their concentration, distribution, and temporal trends in the adjacent natural environment. In total, 83 emerging PFASs from 14 classes were identified, 22 of which were reported for the first time. Authentic standards were synthesized for 13 per- and polyfluoroalkyl ether carboxylic acids (PFECAs), thereby greatly expanding the scope of PFAS-targeted monitoring. The newly identified compounds accounted for 27%-95% of the total PFAS concentrations. Of note, a novel diether carboxylic acid, 2-[2-(trifluoromethoxy)hexafluoropropoxy]tetrafluoropropanoic acid (C7 HFPO-TA) was detected at an extremely high concentration in the fluorochemical zone effluent (447 000 ng/L) and at a median concentration in the fluorochemical zone surface water (670 ng/L), with detectable levels also found in the natural environment, that is, Wangyu River (23 ng/L) and Taihu Lake (5.6 ng/L). The distinct geographic distribution of C7 HFPO-TA suggests transport from the industrial point source to Taihu Lake via the Wangyu River. The concentration of C7 HFPO-TA in Taihu Lake, along with that of many other emerging PFASs, continued to grow in three sampling campaigns from 2016 to 2021. Considering the environmental persistence and toxicity of structurally similar PFECAs (e.g., HFPO-DA), studies on C7 HFPO-TA are urgently needed.

INTRODUCTION: Poly-/per-fluoroalkyl substances (PFAS) are widespread environmental pollutants that may induce metabolic perturbations in humans, including particularly alterations in lipid profiles. Prenatal exposure to PFAS can cause lasting effects on offspring metabolic health, however, the underlying mechanisms are still unknown. OBJECTIVES: The goal of the study was to investigate the impact of prenatal PFAS exposure on the lipid profiles in cord blood. METHODS: Herein, we combined determination of bile acids (BAs) and molecular lipids by liquid chromatography with ultra-high-resolution mass spectrometry, and separately quantified cord blood concentrations of sixteen PFAS in a cohort of Chinese infants (104 subjects) in a cross-sectional study. We then evaluated associations between PFAS concentration and lipidome using partial correlation network analysis, debiased sparse partial correlation, linear regression analysis and correlation analysis. RESULTS: PFAS levels showed significant associations with the lipid profiles; specifically, PFAS exposure was positively correlated with triacylgycerols (TG) and several bile acids. Importantly, exposure to perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorononanoic acid (PFNA) and perfluorohexane sulfonic acid (PFHxS) were associated with increased levels of TGs with saturated fatty acids while multiple classes of phospholipids were decreased. In addition, several free fatty acids showed significant positive correlations with PFOS. CONCLUSIONS: Our results indicated that prenatal exposure to PFAS mediated metabolic changes, which may explain the associations reported between PFAS exposure and metabolic health later in life., Funding agencies:Örebro UniversitySTINT (The Swedish Foundation for International Cooperation in Research and Higher Education) CH2018-7805

The increasingly stringent restrictions on legacy per- and polyfluoroalkyl substances (PFASs) have led to the compensatory use of new fluorinated replacements. These new compounds, hereafter referred to as emerging PFASs, continue to be discovered and are now showing ubiquity in abiotic and biotic environments. Thus, there is an urgent need for robust, yet sensitive analytical methods to determine their occurrence and understand their behavior, fate, impact, and toxicity. Here, we review the up-to-date sample preparation and analytical methodologies for emerging PFASs based on peer-reviewed literature published in the past three years (2015-2018). The determination of emerging PFASs is similar to that of legacy PFASs, with satisfactory performances for most emerging PFASs achieved using conventional extraction and analytical approaches. However, the determination of certain specific analytes remains challenging due to the unavailability of standards and reference materials, low recoveries and matrix effects, background contamination, and poor sensitivities due to in-source fragmentation. Despite recent progress in identifying ionic semi-volatile PFASs with liquid chromatograph-high-resolution mass spectrometry (LC-HRMS), our knowledge on new types of neutral volatile PFASs remains poor due to limited non-target analysis using gas chromatograph (GC)-HRMS., Funding Agencies:National Natural Science Foundation of China 21737004Chinese Academy of Sciences XDB14040202

Driven by increasingly stringent restrictions on long-chain per- and polyfluoroalkyl substances (PFASs), novel fluorinated compounds have emerged on the market. Here we report on the occurrences of several perfluoroalkyl ether carboxylic and sulfonic acids (PFECAs and PFESAs), including hexafluoropropylene oxide dimer and trimer acids (HFPO-DA and HFPO-TA), ammonium 4,8-dioxa-3 H-perfluorononanoate (ADONA), chlorinated polyfluorinated ether sulfonic acid (6:2 Cl-PFESA), and its hydrogen-substituted analogue (6:2 H-PFESA) in surface waters from China ( n = 106), the United States ( n = 12), the United Kingdom ( n = 6), Sweden ( n = 10), Germany ( n = 14), The Netherlands ( n = 6), and Korea ( n = 6). Results showed that HFPO-DA, HFPO-TA, and 6:2 Cl-PFESA (median = 0.95, 0.21, and 0.31 ng/L, respectively) were frequently detected in all countries, indicating ubiquitous dispersal and distribution in global surface waters. The presence of 6:2 H-PFESA was widely detected in China (detection rate > 95%) but not in any other country. Only trace levels of ADONA (0.013-1.5 ng/L) were detected in the Rhine River flowing through Germany. The estimated total riverine mass discharges of HFPO-DA, HFPO-TA, and ΣPFESAs reached 2.6, 6.0, and 4.3 ton/year in five of the major river systems in China. Our results indicated that novel PFECAs and PFESAs might become global contaminants, and future investigations are warranted., Funding Agencies:National Natural Science Foundation of China 21737004 31320103915 Chinese Academy of Sciences XDB14040202

Here, we report on the occurrence of a novel perfluoroalkyl ether carboxylic acid, ammonium perfluoro-2-[(propoxy)propoxy]-1-propanoate (HFPO-TA), in surface water and common carp (Cyprinus carpio) collected from the Xiaoqing River and in 'residents residing near a fluoropolymer production plant in Huantai County, China. Compared with the levels upstream of the Xiaoqing River, HFPO-TA concentrations (5200-68500 ng/L) were approximately 120-1600-times higher downstream after receiving fluoropolymer plant effluent from a tributary. The riverine discharge' of HFPO-TA was estimated to be 4.6 t/yr, accounting for 22% of total PFAS discharge. In the wild common carp collected downstream from the point source, HFPO-TA was detected in the blood (median: 1510 ng/mL), liver (587 ng/g ww), and muscle (118 ng/g ww). The log BCFbiood of HFPO-TA (2.18) was significantly higher than that of PFOA (1.93). Detectable levels of HFPO-TA were also found in the sera of residents (median: 2.93 ng/mL). This is the first report on the environmental occurrence and bioaccumulation of this novel chemical. Our results indicate an emerging usage of HFPO-TA in the fluoropolymer manufacturing industry and raise concerns about the toxicity and potential health risks of HFPO-TA to aquatic organisms and humans., Funding Agencies:National Natural Science Foundation of China 21737004 31320103915 Strategic Priority Research Program of the Chinese Academy of Sciences XDB14040202

Per- and polyfluoroalkyl substances (PFASs) may cross the placental barrier and lead to fetal exposure. However, little is known about the factors that influence maternal-fetal transfer of these chemicals. PFAS concentrations were analyzed in 100 paired samples of human maternal sera collected in each trimester and cord sera at delivery; these samples were collected in Wuhan, China, 2014. Linear regression was used to estimate associations of transfer efficiencies with factors. Chlorinated polyfluorinated ether sulfonates (Cl-PFAESs, 6:2 and 8:2) were frequently detected (>99%) in maternal and cord sera. A significant decline in PFAS levels during the three trimesters was observed. A U-shape trend for transfer efficiency with increasing chain length was observed for both carboxylates and sulfonates. Higher transfer efficiencies of PFASs were associated with advancing maternal age, higher education, and lower glomerular filtration rate (GFR). Cord serum albumin was a positive factors for higher transfer efficiency (increased 1.1-4.1% per 1g/L albumin), whereas maternal serum albumin tended to reduce transfer efficiency (decreased 2.4-4.3% per 1g/L albumin). Our results suggest that exposure to Cl-PFAESs may be widespread in China. The transfer efficiencies among different PFASs were structure-dependent. Physiological factors (e.g., GFR and serum albumin) were observed for the first time to play critical roles in PFAS placental transfer., Funding Agency:Strategic Priority Research Program of the Chinese Academy of Sciences XDB14040202National Natural Science Foundation of China 31320103915 21437002 81372959 81402649Fundamental Research Funds for the Central Universities, HUST 2016YXZD043