Perfluorooctanoic Acid Research Articles

Uptake of Per- and Polyfluoroalkyl Substances in Mixed Forages on Biosolid-Amended Farm Fields.

Models to predict perfluorooctanesulfonic acid (PFOS) concentrations in livestock based on soil concentrations are essential to guide decisions surrounding food testing and farm management. A key parameter in modeling soil-to-livestock exposure pathways is the plant transfer factor (TF) from soil into forages. Uptake of PFOS and other individual per- and polyfluoroalkyl substances (PFASs) were examined in perennial mixed grasses and legumes on PFAS-contaminated farm fields. In a field plot study, PFOS TFs were similar within each plot over three consecutive years but varied 10-fold among the four plots with mean TFs ranging from 0.026 to 0.27. In a multifarm field survey study, mean PFOS TFs ranged from 0.039 to 0.37. Increasing concentrations of two PFOS precursors in soil were significantly associated with increasing PFOS TFs. These data represent a substantial increase in empirical observations of PFAS TFs for grass-based forages for use in modeling soil-to-livestock exposure scenarios.

Occurrence of per- and polyfluoroalkyl substances in drinking water in China and health risk assessment based on a probabilistic approach

Per- and polyfluoroalkyl substances (PFASs) raise concerns due to their widespread distribution, persistence, and toxicity to humans. Current studies lack the use of exposure parameters for Chinese populations and probabilistic risk assessment (PRA) to assess health risks of PFASs. To provide a scientific basis for the standards of PFASs in drinking water in China, data on concentrations of nine PFASs in 649 drinking water samples were collected from China through literature review. The highest concentration of PFASs was 17.41 ± 20.06 ng/L for perfluorobutyric acid (PFBA). Higher concentrations of PFASs were found in the southeastern coastal and in Sichuan Province. The probability of exceeding the standardized limits for drinking water for PFOA and PFOS was 2.71 % and 0.91 %. PRA and deterministic risk assessment (DRA) were used to assess non-carcinogenic risks in different age groups and provinces. Health risks of PFASs from oral exposure notably exceeded dermal contact. The Hazard Quotient (HQ) for oral exposure to perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) exceeded the acceptable level with a certain probability. The non-carcinogenic risk of exposure to PFASs in drinking water was negligible for the majority of the Chinese population. The study indicates that China should increase research on limits of PFASs in drinking water to reduce the health risks.

6669 Association Between Serum Levels of Thyroid Function and Per- and Polyfluoroalkyl Compounds Concentrations in Central Precocious Puberty in Girls

Abstract Disclosure: Y. Li: None. Y. Xing: None. X. Yin: None. J. Yang: None. S. Zang: None. T. Dong: None. Y. Pan: None. J. Dai: None. P. Li: None. Background: Exposure to per- and polyfluoroalkyl substances (PFASs) may interfere with thyroid function in the general population and disturb the timing of puberty onset. Objectives: We investigated the possible relationship between PFASs and thyroid hormone (THs) exposure in girls with central precocious puberty (CPP). Methods: In a prospective study initially established for assessing CPP, 627 serum samples were collected with (n = 226) and without (n = 401) CPP. The concentrations of 25 PFASs, thyroxin (T4), 3,5,3’-triiodothyronine (T3), and 3,3’,5’-triiodothyronine (rT3) were measured. We used logistic regression to examine the association of THs with the odds of having CPP and multiple linear regression to analyze the associations between THs and various PFASs in the CPP and control groups. Results: The levels of T4 in the CPP group were significantly lower than those in the control group, and the levels of T3 and rT3 were significantly higher than those in the control group. After adjusting for confounders, T3 concentrations were associated with 1.526-fold increased odds of having CPP [odds ratio (OR) = 1.526, 95% confidence interval (CI):1.216-1.914]. In the CPP cohort, perfluoroheptanoic acid (PFHpA), perfluoro (2-ethoxyethane) sulphonic acid (PFEESA), and fluorotelomer phosphate diester (6:2/8:2 diPAP) were inversely associated with T3; perfluorobutanoic acid (PFBA) was inversely associated with T4, and PFEESA and 6:2/8:2 diPAP positively associated with T4; PFBA was positively associated with rT3, and perfluorooctane sulfonic acid (PFOS) was inversely associated with rT. In the control cohort, perfluorobutanesulfonic acid (PFBS) was positively associated with T3, and PFEESA and 6:2/8:2 diPAP were inversely associated with T3, and these PFASs had an adverse association with T4. Perfluorohexanoic acid (PFHxA) was positively associated with rT3, and 6:2/8:2 diPAP was negatively associated with rT3. Conclusion: In this study, different measurements of PFASs and THs were observed in the CPP and control groups. Discrepancies in exposure to PFASs were associated with THs in the CPP cohort and healthy girls. Further research is necessary to investigate the mechanism by which PFASs affect the timing of puberty onset and thyroid function. Presentation: 6/1/2024

Adverse Outcomes Following Exposure to Perfluorooctanesulfonamide (PFOSA) in Larval Zebrafish (Danio rerio): A Neurotoxic and Behavioral Perspective.

Toxicity mechanisms of per- and polyfluoroalkyl substances (PFASs), a chemical class present in diverse ecosystems, as well as many of their precursors, have been increasingly characterized in aquatic species. Perfluorooctanesulfonamide (PFOSA, C8H2F17NO2S) is a common precursor of perfluorooctane sulfonic acid (PFOS), a long-chain PFAS. Here, we assessed sub-lethal endpoints related to development, oxidative stress, transcript levels, and distance moved in zebrafish embryos and larvae following continuous exposure to PFOSA beginning at 6 h post-fertilization (hpf). PFOSA decreased survival in fish treated with 1 µg/L PFOSA; however, the effect was modest relative to the controls (difference of 10%). Exposure up to 10 µg/L PFOSA did not affect hatch rate, nor did it induce ROS in 7-day-old larvae fish. The activity of larval fish treated with 100 µg/L PFOSA was reduced relative to the solvent control. Transcripts related to oxidative stress response and apoptosis were measured and BCL2-associated X, apoptosis regulator (bax), cytochrome c, somatic (cycs), catalase (cat), superoxide dismutase 2 (sod2) were induced with high concentrations of PFOSA. Genes related to neurotoxicity were also measured and transcript levels of acetylcholinesterase (ache), elav-like RNA binding protein 3 (elavl3), growth-associated protein 43 (gap43), synapsin II (syn2a), and tubulin 3 (tubb3) were all increased in larval fish with higher PFOSA exposure. These data improve our understanding of the potential sub-lethal toxicity of PFOSA in fish species.

Important role of Chloroflexi: Improved the cooperation of anammox community under PFOS stress

Perfluorooctane sulfonic acid (PFOS) has received extensive attention in recent years due to its persistence and biotoxicity. As an advanced biological nitrogen removal process, anaerobic ammonium oxidation (anammox) is considered to be the most promising process to replace traditional nitrogen removal technology in the future. However, it is still unclear how PFOS affects microbial community and network structure in anammox system. The study found that PFOS had little influence on the nitrogen removal efficiency. Through microbial community and network analysis, the results showed that the typical anammox bacteria (Candidatus_Kuenenia, Candidatus_Jettenia, and Candidatus_Brocadia) enriched with the increasing concentrations of PFOS. Overall network complexity and proportion of positive links was significantly increased under 10 mg/L PFOS. Especially the subnetwork of Chloroflexi owned 100 % positive links under 10 mg/L PFOS, which accounted for 53.62 % of the corresponding overall network. The genus OLB13 and norank_f__Anaerolineaceae from Chloroflexi could cooperate with anammox bacteria to resist the impact of PFOS and further maintained the stability of anammox system. This study provided new insights into the effects of perfluoroalkyl compounds on anammox system.

Zirconium(IV) coordination-mediated rapid and versatile post-modification of polydopamine coating as stationary phase for open-tubular capillary electrochromatography

In recent years, mussel-inspired polydopamine (PDA)-based materials have attracted significant attention in the field of open-tubular capillary electrochromatography (OT-CEC) owing to their diverse and appealing properties. However, previously established functionalized PDA coating-based CEC stationary phases predominantly relied on the latent reactivity of PDA with amine/thiol-containing molecules, limiting the types of applicable modifiers and requiring time-consuming reaction processes. Herein, we presented a versatile and efficient method for the facile and rapid fabrication of diverse functionalized PDA coatings as OT-CEC stationary phases through a Zr(IV) coordination-mediated post-modification strategy. Different kinds of modifiers, including octadecylamine (ODA), lauric acid (LA), and perfluorooctanoic acid (PFOA), were rapidly and robustly grafted onto the PDA coating, verified through multiple characterization techniques. The influences of preparation parameters on the grafting efficiency of the functionalized PDA coating were systematically investigated. Utilizing the Zr(IV)-mediated ODA-, LA- and PFOA-functionalized PDA-based OT-CEC columns, we achieved high-efficiency baseline separation of a series of neutral analytes with excellent repeatability, good stability, and long lifetime. Given the strong universality of the Zr(IV) coordination-mediated post-modification approach, our study provides an effective pathway for advancing the development of a wider range of functional PDA-based chromatographic stationary phases.

Combined environmental relevant exposure to perfluorooctanoic acid and zinc sulfate enhances apoptosis through binding with endogenous antioxidants in Daphnia magna

Perfluorooctanoic acid (PFOA) is a long-chain legacy congener of the per- and polyfluoroalkyl substances (PFAS) family, notorious as a "forever chemical" owing to its environmental persistence and toxic nature. Essential elements such as zinc (Zn) can cause toxic effects when they change their metal speciation and become bioavailable, such as zinc sulphate (ZnSO4). Combined toxicity assessment is a realistic approach and a challenging task to evaluate chemical interactions and associated risks. Therefore, the present study aims to elucidate the acute mixture toxicity (12–48 hours) of PFOA and ZnSO4 in Daphnia magna at environment-relevant concentrations (ERCs, low dose: PFOA 10 μg/L ZnSO4 20 μg/L; high dose: PFOA 20 μg/L ZnSO4 50 μg/L) in terms of developmental impact, apoptosis induction, and interaction with major endogenous antioxidants. Our results showed that deformity rates significantly increased (p < 0.05) with increasing exposure duration and exposure concentrations, compared to the control group. Further, lack of antenna, tale degeneration, and carapace alterations were the most commonly observed deformities following combined exposure to PFOA and ZnSO4, and these malformations were particularly pronounced after 48 h of exposure. Acridine orange (AO) staining was employed to examine apoptosis in D. magna, and apoptotic cells in terms of bright green fluorescence were detected in the abdominal claw carapace, heart, and post-abdominal area following exposure to a high dose of PFOA and ZnSO4. The molecular docking results revealed that both PFOA and ZnSO4 showed strong binding affinities with endogenous antioxidants CAT and GST, where PFOA was more strongly bound with CAT and GST with higher docking scores of -9.59 Kcal/mol and -7.49 Kcal/mol than those with ZnSO4 (-6.70 Kcal/mol and -6.55 Kcal/mol, respectively). In conclusion, the mixture exposure to PFOA and ZnSO4 at the environmental level induce developmental impacts and apoptosis through binding with major endogenous antioxidants in D. magna.

Personal care product use and per- and polyfluoroalkyl substances in pregnant and lactating people in the Maternal-Infant Research on Environmental Chemicals study

BackgroundPer- and polyfluoroalkyl substances (PFAS) are ubiquitous chemicals routinely detected in personal care products (PCPs). However, few studies have evaluated the impact of PCP use on PFAS concentrations in pregnant and lactating populations. ObjectiveWe investigated associations between PCP use and PFAS concentrations in prenatal plasma and human milk. MethodsWe leveraged the Maternal-Infant Research on Environmental Chemicals (MIREC) Study to evaluate the contribution of PCP use on PFAS concentrations in prenatal plasma (6–13 weeks’ gestation; n = 1,940) and human-milk (2–10 weeks’ postpartum; n = 664). Participants reported frequency of use across 8 PCP categories during the 1st and 3rd trimesters, 1–2 days postpartum, and 2–10 weeks’ postpartum. We used linear regression models to quantify covariate-adjusted percent differences and corresponding 95 % confidence intervals. ResultsIn 1st trimester pregnant people, we found higher use of nailcare products (≥once a week vs never: perfluorooctanoic acid (PFOA): 21 % [9.7 %, 32 %]; perfluorooctane-sulfonic acid (PFOS): 11 % [0.3 %, 23 %]), fragrances (daily vs never: PFOA: 14 % [7.8 %, 21 %]; PFOS: 7.8 % [1.3 %, 15 %]), makeup (daily vs. never: PFOA: 14 % [5.8 %, 23 %]), hair dyes (never vs. > twice during pregnancy: PFOA: 8.3 % [2.4 %, 15 %]), and hair sprays or gels (daily vs. never: PFOA: 12 % [5.0 %, 19 %], PFOS: 7.1 % [0.2 %, 15 %], PFHxS: 9.9 % [0.6 %, 20 %]) were associated with higher plasma PFAS concentrations. Similar results were observed for 3rd trimester PCP use and 2–10 weeks’ postpartum human-milk PFAS concentrations. In addition, we found that people using colored-permanent dye 1 to 2 days postpartum had higher Sm-PFOS (18 % [ 2.7, 35]), PFOA (16 % [4.3 %, 29 %]), and perfluorononanoic acid (17 % [3.6 %, 33 %]) postpartum human-milk concentrations. ConclusionsOur results show that PCP use may be a modifiable source of PFAS exposure in pregnant and lactating populations. These results along with growing scientific evidence can help inform PFAS regulation and guide individual choices to reduce PFAS exposure.

Non-extractable residues of perfluorooctanoic acid (PFOA) in soil

Perand polyfluoroalkyl substances have gained increased attention due to their persistence, ubiquitous presence in the environment, and toxicity. We hypothesised that the formation of non-extractable residues [NER] occurs in soils and contributes to the overall persistence of these priority pollutants, and that NER formation is controlled by temperature. To test these hypotheses, we used 14C-labelled perfluorooctanoic acid [PFOA] as target compound, added it to two arable soils (Cambisol, Luvisol), and incubated them at 10°C and 20°C in the dark. To support potential co-metabolic decomposition, some samples were additionally fed with glucose to enhance microbial activity. The PFOA residues were then sequentially extracted using 0.01 M CaCl2, followed by accelerated solvent extraction (ASE) with methanol or methanol/acetic acid after 0, 1, 3, 9, 30, 62, and 90 days of incubation. In addition, we monitored the release of 14C into the gas phase as well as [14C]-PFOA-NER after dry combustion and liquid scintillation counting. After 90 days, we found that the [14C]-PFOA content declined in the extraction order of CaCl2 ((bio)available fraction) > ASE (residual fraction) > NER > gas fraction), with most rapid changes occurring in the first 9 days of incubation. NER formation was different in the two soils and reached 5-9% of the applied amount in the Cambisol and Luvisol, respectively. Noteworthy the proportion of 14C-PFOA in the (bio)available fraction remained relatively stable over time at 56-62% of the applied amount, indicating the reversible transfer into this fraction from a bi-exponentially declining residual (ASE) pool. These dissipation patterns were neither influenced by temperature nor by the addition of glucose. We conclude that NER exist for PFOA, but that the majority of PFOA remains in (bio)available form, thus maintaining toxicity and mobility in soil for prolonged periods of time.

Novel insights into the mechanisms of bioaccumulation and tissue-specific distribution of hexafluoropropylene oxide homologues, novel PFOA alternatives, in zebrafish (Danio rerio)

Hexafluoropropylene oxide trimer acid (HFPO-TA) and hexafluoropropylene oxide tetramer acid (HFPO-TeA) are two novel alternatives of perfluorooctanoic acid (PFOA). However, their toxicokinetics and accumulation mechanisms in fish are still unknown. This study provides the first line of in vivo uptake and depuration kinetic, bioaccumulation mechanism and tissue-specific distribution for HFPO-TA and HFPO-TeA, upon a 28-day water exposure and a 14-day depuration in zebrafish (Danio rerio). HFPO-TeA and HFPO-TA could quickly accumulate in zebrafish, and the highest concentrations of HFPO-TeA (15.4 ± 1.6 nmol/g ww), HFPO-TA (4.95 ± 0.19 nmol/g ww) and PFOA (0.47 ± 0.03 nmol/g ww) were consistently present in the blood, which was followed by liver, kidney, intestine, gill, gonad and brain, while the lowest were observed in the muscle (1.01 ± 0.11, 0.16 ± 0.02, and 0.01 ± 0.001 nmol/g ww, respectively), indicating both higher accumulation potentials of both HFPO homologs than their predecessor PFOA. The tissue protein content, rather than lipid content, played an enhancing role in the enrichment of three target chemicals, exhibiting a significant positive correlation (r = 0.735, p = 0.038 for HFPO-TeA; r = 0.770, p = 0.026 for HFPO-TA and r = 0.942, p = 0.001 for PFOA) between the tissue bioconcentration factor (BCF) and the protein contents in corresponding tissues. This phenomenon was validated by the equilibrium dialysis experiment, molecular docking analysis and molecular dynamics simulation, which consistently indicated that the binding affinities of serum and liver proteins were greatest with HFPO-TeA, followed by HFPO-TA and least with PFOA. These results suggested that the binding of the target chemicals to specific proteins determined their tissue-specific accumulation potentials. Nontarget screening by high resolution mass spectrometry (HRMS) did not identify suspicious degradation products for HFPO-TA, implying the strong persistence of HFPO-TA in fish.

Enhanced selective photocatalytic reduction and oxidation of perfluorooctanoic acid on Bi/Bi5O7I decorated with poly (triazine imide)

Perfluorooctanoic acid (PFOA) is detected widely in surface and groundwater globally. Its removal poses a significant challenge due to its high chemical stability. This study demonstrates efficient PFOA degradation using poly-triazine-imides-tailored defective Bi5O7I (PTI/BB). Under 300W Xe irradiation, 1µg·L-1 PFOA could be degraded to 9.86ng·L-1 after 3hours in the presence of 0.5g·L-1 25% PTI/BB. The mechanism investigation reveals that the oxygen vacancy (OV) in partially reduced Bi/Bi5O7I (BB) generates impurity states, enhancing the light-harvesting capacity. Furthermore, forming a type Ⅱ heterojunction between conjugated PTI and BB facilitates the efficient separation of photogenerated carriers. The resulting photogenerated electrons (reduction) and holes (oxidation) drive hydrogenation reduction and oxidative decarboxylation of PFOA, respectively. This synergistic effect consequently achieves significant defluorination of PFOA. The proposed PFOA degradation pathway via the PTI/BB catalyst offers new insights into the catalyst design for photocatalytic degradation of per- and polyfluoroalkyl substances (PFAS).

Enhanced adsorption of aqueous perfluorooctanoic acid on iron-functionalized biochar: Elucidating the roles of inner-sphere complexation

Perfluorooctanoic acid (PFOA) is ubiquitously detected in various water bodies, which raises the urgent need for developing effective and economic remediation methods in response to its health risks. The adsorptive removal of PFOA by biochar (BC) is regarded as a simple, effective, and economical technique. However, engineered BCs, including FeCl3-activated BC, for PFOA removal and adsorption mechanisms have been ill-studied. In this study, a FeCl3-activated dairy manure-derived biochar (Fe@MBC) was prepared via one-step pyrolysis/activation, and its properties and adsorption characteristics were compared with a pristine manure-derived biochar (P-MBC). The FeCl3 activation largely increased the surface area of Fe@MBC and the deposition of FexOy minerals on surface of Fe@MBC while significantly elevating the surface roughness of Fe@MBC. The maximum adsorption capacity of Fe@MBC for PFOA (233 mg·g−1) was five times higher than that of P-MBC (46 mg·g−1). PFOA adsorption was favorable at low solution pH and was independent on ionic strength, which supported the major contribution by inner-sphere complexation rather than out-sphere complexation. This mechanism was further confirmed by the disappearance of FeO peak on Fourier transform infrared spectrum and the blue-shift of Fe binding energies on X-ray photoelectron Fe 2p spectrum of Fe@MBC after PFOA adsorption. Fe@MBC maintained a near 100 % adsorption capacity for PFOA after 3 cycles of chemical regeneration. Fe@MBC also exhibited efficient removal for PFOA and other PFAS compounds at trace levels in the lake water and dairy effluent. Thus, this study highlights a promising insight for selectively eliminating PFASs from water.

Analyzing the impact of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) on the reproductive system using network toxicology and molecular docking

Growing evidence suggests that perfluorinated compounds (PFCs) contribute to reproductive toxicity, with perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) being the most extensively studied. These chemicals are known to lower testosterone levels and compromise the integrity of the blood-testis barrier. However, the specific mechanisms of their reproductive toxicity remain largely unknown due to research limitations. In this study, we utilized network pharmacology to pinpoint the core genes and signaling pathways implicated in the reproductive toxicity caused by PFOA and PFOS. Molecular docking was employed to validate the interactions between these compounds and their targets. Key targets identified include CCL2, CXCR4, RPS27A, RPL5, PSMA7, and PSMC1, which are crucial in mediating reproductive toxicity. These genes are primarily involved in the chemokine signaling pathway, viral protein interactions with cytokines and cytokine receptors, and ribosomal functions. This study underscores the effectiveness of combining network toxicology and molecular docking to analyze the toxicity and molecular mechanisms of mixed environmental pollutants.

PFOS sub-chronic exposure selectively activates Aβ clearance pathway to improve the cognitive ability of AD mice

Perfluorooctane sulfonate (PFOS), an emerging persistent organic pollutant, has been controversial in its impact on cognitive functions. Our previous research has confirmed that the sub-chronic PFOS exposure leads to neuronal apoptosis in the cerebral cortex, impairing cognitive functions in normal mice. However, our current study presents a surprising finding: sub-chronic exposure to PFOS effectively reduces cognitive impairments in Alzheimer's disease (AD) mice and significantly retards the disease's progression. Our results indicate that PFOS exposure upregulates the expression level of insulin-degrading enzyme (IDE) in the prefrontal cortex (PFC) of AD mice, thereby selectively enhancing the amyloid-beta (Aβ) clearance pathway without affecting the Aβ production. Moreover, PFOS exposure inhibits microglial proliferation and reduces inflammatory cytokines levels in the PFC of AD mice, providing further supporting for the pivotal role of IDE in attenuating AD progression under PFOS exposure. Collectively, our study is the first to demonstrate that sub-chronic PFOS exposure can alleviates cognitive impairments in AD pathology, with the IDE-mediated Aβ clearance pathway potentially playing a critical role.

Perfluorooctanoic acid (PFOA) induces cardiotoxicity by activating the Keap1/Nrf2 pathway in zebrafish (Danio rerio) embryos

Perfluorooctanoic acid (PFOA), a perfluoroalkyl compound, is linked to congenital heart diseases, though its underlying mechanisms remain unclear. We hypothesized that PFOA induces cardiac defects through the inhibition of the Keap1/Nrf2 pathway, leading to oxidative damage in cardiomyocytes. In this study, zebrafish embryos exposed to PFOA showed significant cardiac malformations and dysfunction, characterized by excessive reactive oxygen species (ROS), malondialdehyde (MDA) production, decreased superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities. Additionally, we observed dysregulation in the expression of key cardiac development genes (vmhc, gata4, nkx2.5, and sox9b). PFOA also reduced the expression of keap1, nrf2, and ho-1. After overexpression of Nrf2, levels of ROS and MDA decreased, while levels of SOD, CAT, and GSH-Px increased. Additionally, cardiomyocyte apoptosis and cardiac malformations were alleviated. These findings have suggested that PFOA induces oxidative stress through Keap1/Nrf2 pathway inhibition, ultimately leading to cardiac defects.

A Comprehensive Review of the Occurrence, Distribution, Characteristics and Fate of Per- and Polyfluoroalkyl Substances in the African Continent

AbstractPer- and polyfluoroalkyl substances (PFAS) represent synthetic organic compounds extensively utilized in a variety of domestic and industrial products due to their distinctive characteristics. Designated as persistent organic pollutants (POPs) by the Stockholm Convention, PFAS are recognized for their long-lasting presence, widespread prevalence, and adverse impacts on both the environment and human health. Recently, the United States Environmental Protection Agency (US EPA) revised the guideline limits for perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) in drinking water, setting them at 0.02 and 0.004 ng/L, respectively. Despite the global emphasis on the necessity for monitoring and treating PFAS in environmental media, there is a scarcity of information on PFAS studies in Africa. This gap may be attributed to a lack of modern laboratory facilities, weak governance, and the enforcement of environmental regulations. This study comprehensively reviews PFAS, focusing on key areas such as global guidelines and regulations, sources and distribution in the environmental matrix in Africa, characteristics, environmental fate, reported methods for sampling and analysis in Africa, and the role of government in the National Implementation Plan (NIP) on the continent. Additionally, the study offers recommendations and identifies knowledge gaps. In Africa, PFAS have been detected in various environmental compartments, including drinking water ranging from 0.03 to 200 ng/L, surface water ranging from 0.0254 to 788 ng/L, sediment ranging from 0.50 to 248.14 ng/g, wastewater ranging from 0.9 to 507 ± 257.6 ng/L, seafood ranging from 0.12 to 179.2 ng/g, sludge ranging from 0.01 to 0.098 ng/g, plants ranging from 0.160 to 29.33 ng/g, and indoor dust ranging from 1.3 to 69 ng/g. Notably, perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) are prevalent in samples from various environmental matrices across Africa. Reported sources of PFAS in African countries include municipal waste, hospital waste from medical equipment, discharge from industries, and wastewater treatment plants. Urgent attention is required from decision-makers and researchers in Africa to address PFAS monitoring, regulation, and treatment within the continent. Graphical abstract

Aggregated health risk assessment of perfluoroalkyl acids migrated from convenience food contact materials.

Ingestion of perfluoroalkyl acids (PFAAs) via contaminated food contact materials (FCMs) is an important human exposure source. This study adopts a toxicity equivalent approach to evaluate the collective health risk of multiple PFAAs in FCMs. A comprehensive extraction and analysis of 21 PFAAs in FCMs was performed. Among the analyzed substances, 15 PFAAs were detected. Migration experiment using three food simulants revealed the migration range of seven PFAAs from FCMs into the simulant to be 0.47-46.7ng/cm2. The hazard quotient results suggest minimal health risk, except for 9% of packaged samples where perfluorooctanoic acid (PFOA) poses a higher risk. Utilizing PFOA toxic equivalent concentrations, comprehensive risk calculations showed ∼77% of samples potentially posing elevated health risks due to PFAA exposure. This emphasizes the substantial contribution of PFAAs beyond PFOA and underscores the importance of considering them in related assessments. The aggregated risk assessment reflects actual exposure circumstances more accurately.

Serum levels of per- and poly-fluoroalkyl substances among middle-aged and elderly populations in Beijing and their association with dyslipidemia

Per- and poly-fluoroalkyl substances (PFAS), ubiquitous environmental pollutants, have been reported as possible contributors to human dyslipidemia. However, evidence for emerging PFAS remains scarce. Using a nested case-control study (n = 357) in a middle-aged and elderly population from Beijing, we investigated the serum concentrations of eight traditional and fourteen emerging PFAS and their potential links with dyslipidemia. Perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) were found to be the dominant PFAS. Serum levels of perfluorohexanesulfonic acid (PFHxS) and 6:2 chlorinated polyfluoroalkyl ether sulfonate (6:2 Cl-PFESA/F53B) were associated with higher risk of elevated low-density lipoprotein cholesterol (LDL-C) with odds ratios (OR) of 3.88 (95% CI: 1.44–10.51) and 2.71 (95% CI: 1.11–6.57), respectively. These compounds also positively correlated with high total cholesterol (TC). PFOA, perfluorodecanoic acid (PFDA), and 6:2 Fluorotelomer phosphate monoester (6:2 PAP) were linked to increased risk of high triglycerides (TG) with OR of 2.79 (95% CI: 1.30–6.01), 2.41 (95% CI: 1.27–4.60), and 1.53 (95% CI: 1.05–2.22), respectively. Conversely, perfluorooctane sulfonamidoacetic acid (FOSAA) was negatively associated with high TG levels. These findings indicate that both traditional and emerging PFAS may induce dyslipidemia, emphasizing the potentially serious impact of emerging PFAS on human health.

Determination of per- and polyfluoroalkyl substances (PFAS) in six different fish species from Swiss lakes.

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants with bioaccumulation potential, particularly affecting aquatic ecosystems and human health also via fish consumption. There is therefore a need for reliable extraction methods and studies to accurately assess PFAS levels in fish, crucial for understanding bioaccumulation and potential toxicological effects on both fish and humans through consumption. This study investigated PFAS levels in freshwater fish from Swiss lakes, focusing on six common species: Coregonus wartmanni, Cyprinus carpio, Oncorhynchus mykiss, Perca fluviatilis, Salmo trutta, and Squalius cephalus. Utilizing an optimized QuEChERS extraction method, 15 PFAS were analyzed in 218 fish fillet samples using liquid chromatography-mass spectrometry (LC-MS/MS). The results were compared to EU regulations and EFSA guidelines for tolerable weekly intake (TWI), with a specific focus on correlations between fish size and PFAS concentration. Our findings reveal significant PFAS contamination, particularly in Perca fluviatilis with perfluorooctane sulfonic acid (PFOS) and perfluorohexane sulfonic acid (PFHxS) levels often exceeding EU safety limits. TWI, calculated for a person of 70kg body weight and an intake of 200g of fish fillet, is exceeded in 95% of Coregonus wartmanni, 100% of Squalius cephalus, and in 55%, 50%, and 36% of the specimens Oncorhynchus mykiss, Salmo trutta, and Perca fluviatilis respectively. Correlation analysis between PFAS concentration and fish size in 121 Salmo trutta specimens revealed significant positive correlations for perfluorobutane sulfonic acid (PFBS), perfluorodecanoic acid (PFDA), and perfluorohexane sulfonic acid (PFHxS), and a negative correlation for perfluoropentanoic acid (PFPeA). These results underscore the critical need for continuous monitoring and regulatory efforts to mitigate PFAS exposure risks to both ecosystems and human health.

Toxicokinetic of perfluorinated compounds - A study of liver sequestration in Baltic cod (Gadus morhua callarias) and human dietary exposure

This study assessed the concentrations and temporal trends of perfluorinated compounds (PFCs) in the muscle and liver tissues of Baltic cod (Gadus morhua) from 2017 to 2023. The Environmental Quality Standard (EQS) for biota and the Estimated Weekly Intake (EWI) for human consumers were calculated to evaluate potential health risks associated with PFC exposure. Significant variations in PFC concentrations were observed across different compounds and sampling years. Perfluorooctanoic acid (PFOA) had a mean concentration ranging from 0.03 ng g⁻1 wet weight (ww) to 0.17 ng g⁻1 ww (mean: 0.093 ng g⁻1 ww), while perfluorononanoic acid (PFNA) ranged from 0.05 ng g⁻1 ww to 0.97 ng g⁻1 ww (mean: 0.46 ng g⁻1 ww). Perfluorooctane sulfonate (PFOS) demonstrated mean concentrations between 1.98 ng g⁻1 ww and 9.03 ng g⁻1 ww (mean: 4.78 ng g⁻1 ww). PFOSA exhibited the lowest liver sequestration factor, indicating a higher elimination potential. The EQS for biota, expressed in PFOA-equivalents, ranged from 9.36 ng g⁻1 ww to 28.5 ng g⁻1 ww (mean: 18.5 ng g⁻1 ww), showing an overall increasing trend over the study period. The EWI for Baltic cod muscle (ΣPFAS-4) indicated an average exposure of 1.84 ng kg⁻1 body weight (bw) per week for adults, with a maximum of 3.46 ng kg⁻1 bw per week. For cod liver consumers, the maximum exposure reached 6.45 ng kg⁻1 bw per week, exceeding the Tolerable Weekly Intake (TWI) in some cases. The rising PFC concentrations in Baltic cod, especially in liver tissues, pose health risks to consumers. Ongoing monitoring and risk assessments are essential to reduce the impacts of PFC exposure from seafood.