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| 2. |
- Pan, Yitao, et al.
(författare)
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Analysis of emerging per- and polyfluoroalkyl substances : Progress and current issues
- 2020
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Ingår i: TrAC. Trends in analytical chemistry. - : Elsevier. - 0165-9936 .- 1879-3142. ; 124
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Forskningsöversikt (refereegranskat)abstract
- 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.
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| 3. |
- Pan, Yitao, et al.
(författare)
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Associations of urinary 5-methyl-2'-deoxycytidine and 5-hydroxymethyl-2'-deoxycytidine with phthalate exposure and semen quality in 562 Chinese adult men
- 2016
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Ingår i: Environment International. - Oxford, United Kingdom : Elsevier. - 0160-4120 .- 1873-6750. ; 94, s. 583-590
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Tidskriftsartikel (refereegranskat)abstract
- 5-methyl-2'-deoxycytidine (5mdC) and 5-hydroxymethyl-2'-deoxycytidine (5hmdC), products of DNA methylation and hydroxymethylation processes, have been detected previously in human urine, but their associations with environmental chemicals or healthy outcomes are unclear. The present investigation explored the associations between urinary 5mdC and 5hmdC with phthalate exposure and semen quality. We assessed semen parameters including sperm concentration, motility, and morphology, before measuring urinary 5mdC, 5hmdC and 13 phthalate metabolites among 562 subfertile men from Nanjing, China. Urinary 5mdC and 5hmdC were positively associated with the levels of low molecular weight phthalate metabolites (Low-MWP), high molecular weight phthalate metabolites (High-MWP), and the sum of all phthalate metabolites (ΣPAEs), respectively. Urinary 5mdC was associated with below-reference sperm concentration (odds ratios for increasing quartiles=1.0, 2.2, 3.0, 2.0; p for trend =0.02), sperm motility (1.0, 1.1, 1.9, 1.3; p for trend =0.05), and sperm morphology (1.0, 1.4, 2.3, 1.5; p for trend =0.05). Sperm concentration was associated with the highest quartile of urinary 5hmdC [odds ratio=1.9 (95% CI: 1.1, 3.6)]. Our findings showed significant associations between urinary 5mdC and 5hmdC with phthalate metabolites and semen parameters, which suggested urinary 5mdC and 5hmdC may be promising biomarkers in future epidemiological studies.
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| 4. |
- Pan, Yitao, et al.
(författare)
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Dietary exposure to di-isobutyl phthalate increases urinary 5-methyl-2'-deoxycytidine level and affects reproductive function in adult male mice
- 2017
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Ingår i: Journal of Environmental Sciences(China). - : Elsevier. - 1001-0742 .- 1878-7320. ; 61, s. 14-23
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Tidskriftsartikel (refereegranskat)abstract
- Phthalates are a large family of ubiquitous environmental pollutants suspected of being endocrine disruptors. Epidemiological studies have associated phthalate metabolites with decreased reproductive parameters and linked phthalate exposure with the level of urinary 5-methyl-2'-deoxycytidine (5mdC, a product of methylated DNA). In this study, adult male mice were exposed to 450mg di-isobutyl phthalate (DiBP)/(kg·day) via dietary exposure for 28days. Mono-isobutyl phthalate (MiBP, the urinary metabolite) and reproductive function parameters were determined. The levels of 5mdC and 5-hydroxymethyl-2'-deoxycytidine (5hmdC) were measured in urine to evaluate if their contents were also altered by DiBP exposure in this animal model. Results showed that DiBP exposure led to a significant increase in the urinary 5mdC level and significant decreases in sperm concentration and motility in the epididymis, accompanied with reduced testosterone levels and down-regulation of the P450 cholesterol side-chain cleavage enzyme (P450scc) gene in the mice testes. Our findings indicated that exposure to DiBP increased the urinary 5mdC levels, which supported our recent epidemiological study about the associations of urinary 5mdC with phthalate exposure in the male human population. In addition, DiBP exposure impaired male reproductive function, possibly by disturbing testosterone levels; P450scc might be a major steroidogenic enzyme targeted by DiBP or other phthalates.
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| 5. |
- Pan, Yitao, et al.
(författare)
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First Report on the Occurrence and Bioaccumulation of Hexafluoropropylene Oxide Trimer Acid : An Emerging Concern
- 2017
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 51:17, s. 9553-9560
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 6. |
- Pan, Yitao, et al.
(författare)
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Novel Chlorinated Polyfluorinated Ether Sulfonates and Legacy Per-/Polyfluoroalkyl Substances : Placental Transfer and Relationship with Serum Albumin and Glomerular Filtration Rate
- 2017
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Ingår i: Environmental Science and Technology. - Dordrecht, Neteherlands : Springer Netherlands. - 0013-936X .- 1520-5851. ; 51:1, s. 634-644
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 7. |
- Pan, Yitao, et al.
(författare)
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Worldwide Distribution of Novel Perfluoroether Carboxylic and Sulfonic Acids in Surface Water
- 2018
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 52:14, s. 7621-7629
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 8. |
- Sinisalu, Lisanna, 1993-, et al.
(författare)
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Prenatal exposure to poly-/per-fluoroalkyl substances is associated with alteration of lipid profiles in cord-blood
- 2021
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Ingår i: Metabolomics. - : Springer-Verlag New York. - 1573-3882 .- 1573-3890. ; 17:12
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 9. |
- Yao, Jingzhi, et al.
(författare)
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Nontargeted Identification and Temporal Trends of Per- and Polyfluoroalkyl Substances in a Fluorochemical Industrial Zone and Adjacent Taihu Lake
- 2022
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 56:12, s. 7986-7996
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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