Perfluorinated Substances Research Articles

Determination of Perfluorinated Substances (PFAS) Using LC-ORBITRAP-MS in Certain foodstuffs of Animal Origin According to newly established EU legislation

Determination of Perfluorinated Substances (PFAS) Using LC-ORBITRAP-MS in Certain foodstuffs of Animal Origin According to newly established EU legislation

Metallopolymer-Based Block Copolymers for Perfluorinated Substances (PFAS) and Ion Removal

Similar to the efforts made to combat standard (transition)metal-ion pollution in drinking water such as chromate or lead, a significant endeavor has been directed towards removing perfluorinated organic substances (PFAS),...

Environmental exposure and ecological risk of perfluorinated substances (PFASs) in the Shaying River Basin, China

There have been concerns raised about the environmental effects of perfluoroalkyl substances (PFASs) because of their toxicity, widespread distribution, and persistence. Understanding the occurrences and ecological risk posed by PFASs is essential, especially for the short-chain replacements perfluorobutanoic acid (PFBA) and perfluorobutane sulfonic acid (PFBS), which are now becoming predominant PFASs. The lack of aquatic life criteria (ALC), however, prevents an accurate assessment of the ecological risks of PFBA and PFBS. This study thus investigated the occurrence of 15 PFASs at 29 sampling sites in Shaying River Basin (in China) systematically, conducted the toxicity tests of PFBA and PFBS on eight resident aquatic organisms in China, and derived the predicted non-effect concentration (PNEC) values for PFBA and PFBS for two environmental media in China. The results showed that the total PFASs concentrations (ΣPFASs) ranged from 5.07 to 20.32 ng/L (average of 10.95 ng/L) in surface water, whereas in sediment, ΣPFASs ranged from 6.46 to 20.05 ng/g (dw) (average of 11.51 ng/g). The presence of PFBS was the most prominent PFASs in both water (0.372–8.194 ng/L) and sediment (4.54–15.72 ng/g), demonstrating that short-chain substitution effects can be observed in watersheds. The PNEC values for freshwater and sediment were 6.60 mg/L and 8.30 mg/kg (ww), respectively, for PFBA, and 14.04 mg/L, 37.08 mg/kg (ww), respectively, for PFBS. Ecological risk assessment of two long-chain PFASs, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), and two short-chain PFASs, PFBA and PFBS, using the hazard quotient method revealed that Shaying River and other major River Basins in China were at risk of PFOS contamination. This study contributes to a better understanding of the presence and risk of PFASs in the Shaying River and first proposes the ALCs for PFBA and PFBS in China, which could provide important reference information for water quality standards.

POPs in the Mongolian environment

An environmental and human monitoring project analyzing the persistent organic pollutants (POPs) listed in the Annexes of the Stockholm Convention on POPs was implemented in Mongolia with sampling activities from 2017 until 2019. In support of the global monitoring plan implementation, a total of 51 samples were analyzed for POPs whereby 23 POPs were detected frequently. Two POPs, endrin and hexabromobiphenyl (PBB 153), were not quantified in any of the samples; toxaphene was found only twice in air samples; and dicofol, pentachlorophenol, and short-chain chlorinated paraffins were analyzed only in one human milk sample. Most results were for perfluorooctanoic acid (PFOA, 32 of 43 samples) and perfluorooctanesulfonic acid (PFOS, 31 of 43 samples). With respect to detection frequency, dioxin-like polychlorinated biphenyls (dl-PCB) were detected in 100% of the samples analyzed (N = 28). On scale, highest amounts were found in soil samples, almost 30 000 ng/g for lindane, more than 13 000 ng/g for α-hexachlorocyclohexane (α-HCH), and almost 10 000 ng/g for dichlorochlorodiphenyltrichloroethane (DDT) and its transformation products. The soil and ambient air samples were the drivers towards highest values in the abiotic samples, due to the presence of legacy POPs such as DDT, indicator PCB, HCHs but also hexachlorobenzene (HCB), and pentachlorobenzene (PeCBz). Concentrations of dioxin-like POPs were low in general as were the perfluorinated substances (PFAS). With respect to brominated flame retardants, the presence of hexabromocyclododecane in air samples was surprising. At present, the analytical capacity to analyze POPs in various matrices under the global monitoring plan for POPs is being set-up to strengthen future environmental monitoring activities in Mongolia.

HRMS screening of organophosphate flame retardants and poly-/perfluorinated substances in dust from cars and trucks: Occurrence and human exposure implications

Time spent within vehicles' cabin has been largely increased during the last years. As a result, the assessment of indoor dust quality is meaningful since dust can be a source of numerous emerging contaminants associated with adverse effects in human health. To this end, fourteen cars and ten trucks from the city of Thessaloniki, Northern Greece were selected to assess the quality of vehicles' microenvironments. An HRMS-based strategy was deployed for the target and non-target analysis of the collected samples. The target approach aimed at the accurate mass screening of nine organophosphate flame retardants (OPFRs) and nine per-/polyfluorinated compounds (PFAS), revealing mean concentrations for the OPFRs varied from <MQL–3409 ng/g for tris(1,3-dichloro-2-propyl) phosphate (TDCP), while the PFASs were either not detected (<MDL) or detected below the quantification limit (<MQL). To exploit the advanced technology of HRMS, a non-target analysis (NTA) workflow was also designed and employed, allowing the identification of 17 non-targets (plasticizers, PPCPs, pesticides and industrial chemicals) at identification confidence levels from 3 to 1. The statistical analysis between the positive findings and vehicles' conditions evidenced a possible of association just for individual cases. Lastly, a preliminary evaluation of human exposure to the target analytes was applied with the view to assess the potential harmful effects. All values were < 1 indicating no special effects because of exposure to this concentration level.

Preparation of cationic hierarchical porous covalent organic frameworks for rapid and effective enrichment of perfluorinated substances in dairy products

Perfluorinated substances (PFASs) are harmful pollutants that have environmental persistence and high bioaccumulation. Effective sample pretreatment must be performed to detect trace or even ultra-trace PFASs in actual samples because of their extremely low contents in complex samples. In this study, a cationic hierarchical porous covalent organic frameworks (C-H-COF) were customized via a template-assisted strategy using polystyrene spheres (PS) as sacrificial materials and a post-synthetic modification method. C-H-COF showed good adsorption selectivity for PFASs owing to the dual effects of the full utilization of the internal adsorption sites and electrostatic interaction. The key role of electrostatic attraction in the extraction of PFASs using C-H-COF was further proven by density functional theory (DFT) calculations. The maximum adsorption capacity of the C-H-COF for perfluorooctanoic acid (PFOA) was 400 mg·g⁻1, which was superior to that of microporous COFs (M-COF) and hierarchical porous COFs without cationic functionalization (H-COF). Accordingly, an analytical method for sensitively detecting five PFASs was established by employing C-H-COF as a dispersive solid phase extraction (DSPE) adsorbent combined with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), and the limits of detection were 0.011‒0.29 ng·L⁻1. Moreover, the hierarchical porous structure of the C-H-COF accelerated the mass transfer of analytes so that the extraction process could be completed within 10 min. This method was employed to analyze PFASs in dairy products, in which the ultra-trace levels of analytes were quickly determined with spiked recoveries of 80.1‒112.6%. This work not only provides a rational synthetic strategy for novel ionic hierarchical porous COFs but also helps to expand the application of COFs in sample pretreatment.

Ecosystem specific accumulation of organohalogenated compounds: A comparison between adjacent freshwater and terrestrial avian predators

Insight into processes determining the exposure of organohalogenated contaminants (OHCs) in wildlife might be gained from comparing predators in different ecosystems. This study compared two avian predator species with similar food chain lengths: the goldeneye duck (Bucephala clangula) and the tawny owl (Strix aluco) breeding in adjacent freshwater- and terrestrial ecosystems in central Norway. We measured lipophilic organochlorines (OCs) and protein-bound perfluorinated substances (PFASs) in eggs of the two species over 21 years (1999–2019). Across years, the proportional distribution of OCs (∼90% of the ΣOHC load) relative to PFASs (∼10%) was similar in the two species. Moreover, ΣOC concentrations were similar between the species, but PFAS compounds were 2–12 times higher in the goldeneyes than in tawny owls. OC-pesticides dominated in tawny owls (∼60% of ΣOC), whereas persistent polychlorinated biphenyl (PCBs) congeners were the main OC components in goldeneyes (∼70% of ΣOC). The lipid-normalized concentrations of most OC-pesticides and the less persistent PCB101 declined significantly in both species. Hexachlorobenzene (HCB), p,p’-dichlorodiphenyldichloroethylene (p,p’-DDE), and more persistent PCBs decreased in tawny owls, while they tended to increase in goldeneyes. The increase in HCB was particulary robust. Among the PFASs, contrasted temporal trends were found across the species for four out of 11 compounds: PFOS declined while most perfluorocarboxylic acids (PFCAs) increased in tawny owls. In contrast, most PFASs were stable in goldeneyes. Moreover, there was no annual covariance between the OHC exposure in the two species: i.e., high concentrations in one species in a given year did not translate into high concentrations in the other. Hence, the two avian predators in adjacent ecosystems seem to be subject to different processes determining the OHC exposure, probably related to variation in diet and climate, long-range transport of different contaminants, and emissions of pollution locally.

Multiple pollutants in groundwater near an abandoned Chinese fluorine chemical park: concentrations, correlations and health risk assessments

Contamination and adverse effects from various pollutants often appear in abandoned industrial regions. Thus, nine groundwater samples were collected from the vicinity of the fluorochemical industry in Fuxin City, Liaoning Province, to determine concentrations of the ten heavy metals arsenic (As), chromium (Cr), cadmium (Cd), lead (Pb), nickel (Ni), copper (Cu), manganese (Mn), zinc (Zn), iron (Fe) and mercury(Hg), as well as those of fluorine (F−) and eighteen poly- and perfluorinated substances (PFASs), analyse correlation relationships, and assess the health risks for different age groups. The results showed that the levels of fluorine (F−) (0.92–4.42 mg·L−1), Mn (0.0005–4.91 mg·L−1) and Fe (1.45–5.61 mg·L−1) exceeded the standard limits for drinking water. Short chain perfluorobutanoic acid (PFBA) (4.14–2501.42 ng·L−1), perfluorobutane sulfonate (PFBS) (17.07–51,818.61 ng·L−1) and perfluorohexanoic acid (PFHxA) (0.47–936.32 ng·L−1) were the predominant substances from the PFASs group. No individual PFASs levels had significant relationships with F− or heavy metal contents. There was a positive relationship between short chain PFASs concentrations and water depth and a negative relationship between long chain PFASs concentration and water depth. The hazard quotient (HQ) decreased in the order F− > heavy metals > PFASs and also decreased for older age groups. In addition, As, Fe, Mn and perfluorooctanoic acid (PFOA) were the main sources of risk from the heavy metal and PFASs groups, respectively.

Cancer incidence in a Swedish cohort with high exposure to perfluoroalkyl substances in drinking water

BackgroundThe use of firefighting foams at a military airport resulted in high levels of perfluorinated substances (PFAS) in the drinking water distributed to one-third of households in the Swedish municipality of Ronneby between the mid-1980s and the end of 2013. MethodThe Ronneby Register Cohort, a large cohort comprising all individuals (N = 60,507) who ever lived in the Ronneby municipality during the period of drinking water contamination, was linked to the Swedish Cancer Register 1985–2016. Individual exposure was classified based on comprehensive data on yearly residential address and water distribution. External analysis explored standardized cancer incidence ratios (SIR) for residents never, or ever, residing in the contaminated water district, compared with those residing in other towns in the same county as reference population. Cox models provided hazard ratios (HR) for different exposure groups within the cohort. Results5,702 individuals with cancer were identified. SIR for overall cancer was 1.04 for men (95%CI 0.96–1.12) and 0.89 for women (95%CI 0.82–0.96) who ever lived in the contaminated drinking water area. Kidney cancer, which was reported with increased risk in C8 study, showed somewhat elevated HR in this study (HR 1.27; 95%CI 0.85–1.89). The HR was modestly elevated for bladder cancer (HR 1.32; 95%CI 1.01–1.72), and reduced for prostate cancer (HR 0.83; 95%CI 0.71–0.98). In subjects who ever lived in the contaminated water area during 2005–2013, when exposure was estimated to be highest, higher risks for kidney cancer (HR 1.84; 95%CI 1.00–3.37) but lower for prostate cancer (HR 0.76; 95%CI 0.59–0.98) were observed. ConclusionAnalysis of this large cohort exposed to high levels of PFAS, dominated by PFHxS and PFOS, revealed no evidence for an overall increased risk of cancer. A moderately increased risk of kidney cancer was observed, in accordance with previous findings after PFAS exposure dominated by PFOA.

Linking field and laboratory studies: Reproductive effects of perfluorinated substances on avian populations.

Although both laboratory and field studies are needed to effectively assess effects and risk of contaminants to free-living organisms, the limitations of each must be understood. The objectives of this paper are to examine information on field studies of reproductive effects of perfluorinated substances (PFASs) on bird populations, discuss the differences among field studies, and then place those results in context with laboratory studies. Hypotheses to explain the divergences between field studies and between laboratory and field studies will be discussed. Those differences include mixture issues, misattribution of the mechanism or the specific PFAS causing impairments, as well as other possible reasons. Finally, suggestions to better link laboratory and field studies will be presented. Integr Environ Assess Manag 2021;17:690-696. Published 2021. This article is a US Government work and is in the public domain in the USA.

Poly- and perfluorinated substances in environmental water from the Hartbeespoort and Roodeplaat Dams, South Africa

Concentrations of poly- and perfluorinated substances (PFASs) were determined in Hartbeespoort and Roodeplaat Dams, South Africa. Water samples were collected from the dams in February–March, and May–June, representing southern hemisphere summer and winter seasons, respectively. Solid phase extraction (SPE) was used to extract the analytes from the water samples and liquid chromatography-tandem mass spectrometry (LC-MS/MS) used for analysis. The mean PFAS concentrations detected ranged from 1.38–346.32 ng∙L-1 and 2.31–262.29 ng∙L-1 in the Hartbeespoort Dam and Roodeplaat Dam, respectively. Perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorohexane sulfonic acid (PFHxS) and perfluoroheptanoic acid (PFHpA) were the most dominant PFASs detected. The PFAS concentrations detected were higher in summer than in winter, but the difference between seasons was not statistically significant (p = 1). Furthermore, the concentrations of short-chain PFASs were higher than the longer chains. Overall, the PFAS concentrations in the present study are comparable to those reported in other parts of South Africa, and also Ghana, higher than the concentrations reported in Uganda, Singapore, and Vietnam, and lower than those in Germany, Japan and China. The measured concentrations of PFOA and PFOS raise concerns of human exposure to these chemicals since they are above the USEPA advisory limit. This suggests that communities living within the vicinity of the dams are most likely to be exposed to these chemicals.

PFAS Environmental Pollution and Antioxidant Responses: An Overview of the Impact on Human Field.

Due to their unique properties, perfluorinated substances (PFAS) are widely used in multiple industrial and commercial applications, but they are toxic for animals, humans included. This review presents some available data on the PFAS environmental distribution in the world, and in particular in Europe and in the Veneto region of Italy, where it has become a serious problem for human health. The consumption of contaminated food and drinking water is considered one of the major source of exposure for humans. Worldwide epidemiological studies report the negative effects that PFAS have on human health, due to environmental pollution, including infertility, steroid hormone perturbation, thyroid, liver and kidney disorders, and metabolic disfunctions. In vitro and in vivo researches correlated PFAS exposure to oxidative stress effects (in mammals as well as in other vertebrates of human interest), produced by a PFAS-induced increase of reactive oxygen species formation. The cellular antioxidant defense system is activated by PFAS, but it is only partially able to avoid the oxidative damage to biomolecules.

PFAS and cholesterol in epidemiological studies: causality, biomarkers, mixtures and relative potency

Concern continues about adverse effects, including raised cholesterol, associated with perfluorinated substances (PFAS) in general and perfluoro-octanoic acid (PFOA) in particular, and whether all associations are truly causal. There have been numerous epidemiological studies of blood concentrations (usually cross-sectional studies of serum concentrations) of PFOA and cholesterol. In addition to the usual sources of potential confounding, using serum PFOA as the exposure raises the possibility of confounding by physiology, for example, enterohepatic recirculation and correlated absorption of both PFAS and bile acids or cholesterol. Mechanistic toxicology studies of the pharmacodynamics of PFOA and cholesterol may shed light on the plausibility of these various causal and artefactual contributions to the associations, but the large and complex C8 dataset offers the possibility of assessing directly the strength of the epidemiological evidence in favour of this association being causal.District level measures of exposure offer a way of addressing exposure response immune from confounding by physiology, acting as instrumental variables for exposure. For 40,000 adults 18+ in the C8 study population, there was a strong and significant association of cholesterol, in relation to serum PFOA, adjusting for sex, age, race and other measured potential confounders. New results using the instrumental variable approach by water district contamination level showed a similar, significant dose response, and the concordance of the two approaches strongly supports a causal interpretation of the association. Comparison of slopes suggests that about half of the association with PFOA in single pollutant models is explained by confounding. A similar change in slope is achieved in cross sectional analyses by adding adjustment for other PFASs in the blood. Slopes for each PFAS in multi-pollutant models thus allow the estimation of relative potency which is helpful for risk assessment in populations with mixed PFAS exposure.

Environmental factors affecting degradation of perfluorooctanoic acid (PFOA) by In2O3 nanoparticles

Nanophotocatalysts have shown great potential for degrading poly- and perfluorinated substances (PFAS). In light of the fact that most of these catalysts were studied in pure water, this study was designed to elucidate effects from common environmental factors on decomposing and defluorinating perfluorooctanoic acid (PFOA) by In2O3 nanoparticles. Results from this work demonstrated that among the seven parameters, pH, sulfate, chloride, H2O2, In2O3 dose, NOM and O2, the first four had statistically significant negative effects on PFOA degradation. Since PFOA is a strong acid, the best condition leading to the highest PFOA removal was identified for two pH ranges. When pH was between 4 and 8, the optimal condition was: pH = 4.2; sulfate = 5.00 mg/L; chloride = 20.43 mg/L; H2O2 = 0 mmol/L. Under this condition, PFOA decomposition and defluorination were 55.22 and 23.56%, respectively. When pH was between 2 and 6, the optimal condition was: pH = 2; sulfate = 5.00 mg/L; chloride = 27.31 mg/L; H2O2 = 0 mmol/L. With this condition, the modeled PFOA decomposition was 97.59% with a defluorination of approximately 100%. These predicted results were all confirmed by experimental data. Thus, In2O3 nanoparticles can be used for degrading PFOA in aqueous solutions. This approach works best when the target contaminated water contains low concentrations of NOM, sulfate and chloride and at a low pH.

Filter function of graphene oxide: Trapping perfluorinated molecules.

We need clean drinking water, but current water purification methods are not always sufficient. This study examines the binding and binding mechanisms when graphene oxide is used as a filter material for removing perfluorinated substances and trihalomethanes. We use density functional theory calculations to examine the binding of the harmful molecules on graphene oxide. Our results indicate that the binding energies between graphene oxide and the investigated molecules are in the range of 370-1450 meV per molecule, similar to the binding energies obtained in other studies, where adsorption of similar size molecules onto graphene oxide has been investigated. This indicates that graphene oxide has the potential to separate the molecules of interest from the water. Significant contribution to the binding energies comes from the van der Waals (dispersion) interaction between the molecule and graphene oxide, while the hydrogen bonding between the functional groups of graphene oxide and the hydrogen atoms in functional groups on the molecules also plays a role in the binding.

Serum levels of a range of perfluorinated substances (PFAS) after drinking water exposure in three populations living around military and civil airfields in Sweden

Serum levels of a range of perfluorinated substances (PFAS) after drinking water exposure in three populations living around military and civil airfields in Sweden

Poly- and perfluoroalkyl substances in a drinking water treatment plant in the Yangtze River Delta of China: Temporal trend, removal and human health risk

Poly- and perfluorinated substances (PFASs) have been found ubiquitously all over the world in drinking water, thus attracting concern of public opinion and regulators. The present study was carried out in a drinking water treatment plant (DWTP) located in the city of Changzhou (China), near the Yangtze River Delta. 31 PFASs concentrations were analyzed in the DWTP process water flows, as well as in its upstream source water (Yangtze River and Desheng River) and downstream public supply water. 13 PFASs were detected in source and drinking water with total concentration of 25–38 ng/L, which were higher for Yangtze River than Desheng River. The predominant contaminants were perfluorobutanesulfonate, perfluorooctanoic acid and perfluorobutanoic acid. In addition, HFPO-TA was identified for the first time in Yangtze River. Data indicate that PFASs discharge in Yangtze River is remarkable, with a mass flow in the wet season (i.e. summer) up to 83 kg/d. However, oxidizable precursors (quantified by total oxidizable precursor assay) were 21–88% of total PFASs, constituted mainly by short-chain homologues. Taking these precursors into account, an opposite picture is observed: Desheng River had higher concentration of total PFASs than Yangtze River. Results for the DWTP indicate that PFASs concentration was not affected by conventional treatment processes and remained unchanged also in the downstream public water supply pipelines. More importantly, granular activated carbon removed effectively only sulfonated and carboxylated congeners, but was inefficacious with oxidizable precursors. The present study demonstrates that, despite implementation of treatment by granular activated carbon, there is still a risk for citizens deriving from drinking water of Yangtze River.

Perfluoroalkyl Contaminant Exposureand Effects in Tree Swallows Nesting at Clarks Marsh, Oscoda, Michigan, USA.

A site in northeastern Michigan, Oscoda Township, has some of the highest recorded exposure in birds to perfluorinated substances (PFASs) in the United States. Some egg and plasma concentrations at that location exceeded the lowest reproductive effect threshold established for two avian laboratory species. The objectives of this study were to determine whether there were reproductive effects or physiological responses in a model bird species, the tree swallow (Tachycineta bicolor), associated with this extremely high exposure to PFASs. The lack of exposure above background to other contaminants at this site allowed for an assessment of PFAS effects without the complication that responses may be caused by other contaminants. A secondary objective was to determine the distribution of PFASs in multiple tissue types to better understand and interpret residues in different tissues. This can best be done at highly exposed locations where tissue concentrations would be expected to be above detectable levels if they are present in that tissue. There were no demonstrable effects of PFAS exposure on reproduction nor on most physiological responses.

Perfluoroalkyl Substances in Water from the Yangtze River and Its Tributaries at the Dividing Point Between the Middle and Lower Reaches.

The Yangtze River drainage basins are China's most important economic development zones and also the locations of several large-scale fluorine chemical industries. In order to reveal the contribution from the tributaries at the dividing point between the middle and lower reaches of the Yangtze River with respect to perfluorinated substances (PFASs), 17 PFAS compounds in surface water, groundwater, and tap water samples were analyzed in the tributary system of the Jiujiang section of the Yangtze River. The total concentrations of PFASs in the surface waters ranged from 7.8 to 586.2ng/L. High proportion of short-chain compound PFBS in surface waters in Nanchang City, Poyang Lake, and the Yangtze River was observed which is likely of WWTPs' origin.

Seasonal accumulation of persistent organic pollutants on a high altitude glacier in the Eastern Alps

The seasonal accumulations of perfluorinated substances (PFAS), polybrominated diphenyl ethers (PBDE) and polycyclic aromatic hydrocarbons (PAH) were measured in a 10 m shallow firn core from a high altitude glacier at Mt. Ortles (Italy, 3830 m above sea level) in South Tyrol in the Italian Eastern Alps. The most abundant persistent organic pollutants of each group were perfluorobutanoic acid (PFBA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA) (for PFASs); BDE 47, BDE 99, BDE 209 (for PBDEs) and phenanthrene (PHE), fluoranthene (FLA) and pyrene (PYR) (for PAHs). All compounds show different extents of seasonality, with higher accumulation during summer time compared to winter. This seasonal difference mainly reflects meteorological conditions with a low and stable atmospheric boundary layer in winter and strong convective activity in summer, transformation processes during the transport of chemicals and/or post-depositional alterations. Change in the composition of the water-soluble PFCAs demonstrates the influence of meltwater percolation through the firn layers.