Levels Of Perfluoroalkyl Acids Research Articles

Relationship Between Perfluoroalkyl Acids in Human Serum and Sjogren's Syndrome: A Case-Control Study of Populations in Hangzhou, China.

Exposure to perfluoroalkyl acids (PFAAs) has been found to elicit a range of detrimental effects on human health. However, limited research has investigated the impact of PFAAs on immunity and immune disorders such as Sjogren's syndrome, with existing studies yielding inconsistent results. This study was conducted in Hangzhou, China, with an initial cohort comprising 156 healthy individuals and 162 patients diagnosed with Sjogren's syndrome. We quantified serum levels of PFAAs and examined associations between PFAAs and both susceptibilities to the development of Sjogren's syndrome and immune marker concentrations. Nine PFAAs were frequently detected in the serum, with perfluorooctanoate (PFOA) exhibiting the highest concentration, followed by perfluorooctanesulfonate (PFOS). Exposure to PFOA and perfluorotridecanoate (PFTrDA) was inversely associated with the disease. Furthermore, a negative correlation between PFOA and C-reactive protein (CRP) was observed. These findings suggest that exposure to specific PFAAs may impact the immune system and potentially influence the development of Sjogren's syndrome.

Distribution, trophic magnification and risk of trace metals and perfluoroalkyl acids in marine organisms from Haizhou Bay

Haizhou Bay, a semi-enclosed key aquaculture area in East China, has had relatively limited research focused on trace metals and perfluoroalkyl acids (PFAAs) in its biota. This study characterized the distribution, biomagnification and health risks of selected trace metals and PFAAs in various marine organisms from Haizhou Bay. Among the species examined, zinc (Zn) was the most prevalent metal, followed by copper (Cu) and chromium (Cr), whereas cadmium (Cd), total mercury (THg), and methylmercury (MeHg) contents were relatively low. Perfluorooctane sulfonate (PFOS) was the most abundant PFAA, followed by perfluorooctanoic acid (PFOA). The calculated trophic magnification factors (TMFs) were above one for Cr, THg, MeHg, and all PFAAs except perfluorobutanoic acid (PFBA) and perfluorotetradecanoic acid (PFTeDA). Across animal groups, gastropods exhibited relatively low levels of THg, MeHg, and perfluorosulfonic acids (∑PFSAs). By comparison, fish generally had lower levels of Cd and Cu compared to other animal groups, and demersal fish had significantly higher MeHg compared to gastropods. Certain organisms, such as cephalopods and shrimps, were found to pose potential health risks due to elevated levels of Cd, while levels of other studied metals, PFOS and PFOA generally appeared to be within safe limits for human consumption. Further research is needed to assess the sources and impacts of these and other contaminants.

Current status and risk assessment of perfluoroalkyl acids in surface water and sediments of the Yellow River in Shandong, China

The Yellow River is the main source of water for urban and rural area and agricultural irrigation in northern China. Herein, the distribution and risk assessment of perfluoroalkyl acids (PFAAs) were investigated from the Yellow River in Shandong Province, China. The total concentration of PFAAs (∑PFAAs) in surface water and sediments were 37.5–2128 ng/L (mean: 167 ng/L) and not detected−6.95 ng/g dry weight (dw) (mean: 1.02 ng/g dw), respectively. Short-chain PFAAs-perfluorobutanoic acid (PFBA), perfluorohexanoic acid (PFHxA), and perfluorobutane sulfonic acid (PFBS) were the most prevalent PFAAs in surface water. Source analysis showed that firefighting foam (proportion: 31.3 %) and textile treatments and food packaging (proportion: 30.3 %) were the main sources of PFAAs in water. Based on the concentration of PFAAs in water, ecological and potential human health risks were assessed. Perfluorooctanoic acid (PFOA), perfluorononanoate (PFNA), perfluorodecanoate (PFDA) and perfluoroundecanoic acid (PFUnDA) posed nonnegligible ecological risk for some aquatic organisms. Levels of PFAAs (e.g., PFOA, PFNA, and PFDA etc.) in some water samples were higher than the advisory guidelines of PFAAs concentrations in water worldwide, indicating a potential human health risk. Therefore, PFOA, PFNA, PFDA, and PFUnDA are the key focus of pollutants in the water of the Yellow River in Shandong Province, and the standards and limits of these PFAAs in environments including surface water and sediment should be promoted.

Influence of age on the concentrations of perfluoroalkyl acids (PFAA) in the tissues of perch (Percafluviatilis)

Globally, perfluoroalkyl acids (PFAA) are ubiquitous due to their almost unlimited applications in industry and households and are detected in a wide variety of matrices.Aquatic ecosystems are of particular importance due to the spread of PFAA via water fluxes. The majority of published studies describe PFAA concentrations in fish or aquatic mammals, but not the dependence of PFAA concentrations in tissues and organs in fish of different ages. Since this is very important for understanding the accumulation behavior of these substances our study systematically investigates the influence of age on the PFAA concentration in the tissues of 74 perches (Perca fluviatilis), a very popular edible fish. Fish are particularly suitable as indicators of PFAA contamination of water because of their uptake via water (gills and skin) and food (predominantly piscivorous diet). The mean total PFAA concentrations (as the sum of the individual concentrations of 11 compounds) were: 114 μg/kg (kidney), 112 μg/kg (heart), 79.9 μg/kg (liver), 78.4 μg/kg (spleen), 64.6 μg/kg (gills) and 21.7 μg/kg (muscle), with longer-chain compounds accounting for 90% of the substances. Perfluorooctanesulfoic acid (PFOS) accounted for the largest percentage of the total PFAA concentration in all tissues at 43–63%. With the exception of the heart and spleen, a significant increase in total concentrations was observed with increasing age of the perch. The strongest correlation was observed for the kidney, followed by the liver and gills. With regard to their consumption as human nutrition the tolerable weekly PFAA intake of 4.4 ng/kg bodyweight and week for the sum of the 4 EFSA PFAA in adults and children was exceeded many times over (860% and 1600% respectively) with an average fish consumption per week. The maximum PFAA levels set in the E.U. since January 2023 were exceeded five times.

Assessment of activated carbon as a sorbent amendment for immobilizing perfluoroalkyl acids for surface sediment remediation

The detection of elevated levels of perfluoroalkyl acids (PFAAs) in sediments has become a significant concern, urgently requiring management and remediation efforts. In this study, we investigated the effectiveness of industrially cost-effective activated carbon (AC) in remediating PFAA-contaminated sediments at different disturbance intensities and explored the sorption capacity of AC under broad environmentally relevant conditions and in response to environmental variations. AC exhibited high sorption effectiveness for PFAAs (excluding perfluorobutanoic acid < 40 %) across different pH, ionic strengths (IS), and dissolved organic matter (DOM). However, the increase in pH or reduction in IS might reactivate partially immobilized PFAAs. DOM outcompeted longer-chain PFAAs for sorption sites, resulting in their reactivation on AC, while it showed a stronger sorption than a competitive effect on shorter-chain PFAAs. The 192-day remediation experiment showed that AC significantly deactivated mobile PFAAs and decreased PFAA release by 45.5 %–99.2 % and 61.0 %–98.8 % under weak and intense disturbances, respectively, when compared with untreated sediment. Although intense disturbance led to an increase in PFAA release, the PFAA levels in the water column of the AC group after intense disturbance were comparable or even lower than those before intense disturbance, primarily owing to the secondary sorption of suspended AC. These findings are crucial for the appropriate and safe use of AC for PFAA sequestration, the management of PFAA-contaminated sediments, and the development of effective sediment remediation strategies.

Removal of perfluoroalkyl acids (PFAAs) from aqueous solution by water hyacinth (Eichhornia crassipes): Uptake, accumulation, and translocation

Although Eichhornia crassipes, commonly known as water hyacinth, has been widely used in wastewater treatment, further investigations are still needed to explore the removal efficiency of perfluoroalkyl acids (PFAAs) from the aqueous environment using this floating aquatic plant. In this study, a hydroponic experiment was conducted to assess accumulation, bioconcentration factors (BCFs), translocation factors (TFs), and removal rates of eight PFAAs by water hyacinth. The obtained results indicated that all PFAAs, including five perfluoroalkyl carboxylic acids (PFCAs) with chain lengths C4-C8 and three perfluoroalkyl sulfonic acids (PFSAs) with C4, C6, and C8, were readily accumulated in water hyacinth. Throughout the duration of the experiment, there was a noticeable increase in PFAA concentrations and BCF values for different plant parts. For the root, PFAAs with more carbon numbers showed a higher uptake than the shorter homologues, with PFSAs being more readily accumulated compared to PFCAs with the same carbon number in the molecules. In contrast, the levels of long-chain PFAAs were comparatively lower than those of short-chain substances in the stem and leaf. Notably, PFAAs with less carbon numbers, like PFPeA, PFBA, and PFBS, showed a remarkable translocation from the root to the stem and leaf with TFs >1. For the whole plant, no significant correlation was found between BCFs and organic carbon-water partition coefficients (Koc), octanol-water partition coefficients (Kow), membrane-water distribution coefficients (Dmw), or protein-water distribution coefficients (Dpw). The removal rates of PFAAs ranged from 40.3 to 63.5 % throughout the three weeks of the experiment while the removal efficiencies varied from 48.9 % for PFHxS to 82.6 % for PFPeA in the last week.

Factors affecting the occurrence and accumulation of perfluoroalkyl acids in indoor dust in Tainan, Taiwan

Perfluoroalkyl acids (PFAAs) are environmentally and biologically persistent chemicals. In this study, we investigated the concentrations of six PFAAs in dust samples collected from different indoor environments in a college campus in Tainan, Taiwan, and assessed the health risk of PFAAs exposure to college students. We also analyzed the effects of dust characteristics (total organic carbon, moisture content, and dust content) on PFAAs levels. With regard to the space type, the median of total PFAAs concentrations were in the order of laboratories (528.9 μg kg−1) > offices (304.2 μg kg−1) > dormitories (180.1 μg kg−1) > classrooms (105.1 μg kg−1). With regard to the height from the ground, the median total PFAAs concentrations were in the order of dust near the floors (>2 m; 383.6 μg kg−1) > near the ceiling (0–2 m; 202.5 μg kg−1) > on the ground (0 m; 145.6 μg kg−1). The main species of PFAAs, perfluorooctane sulfonate and short-chain perfluoroalkyl carboxylates, accounted for respectively 30%–60% and ∼20%–37% of total PFAAs pollution in the indoor space types and sampling heights under consideration. The average daily intake (ADI) values of six PFAAs for college students were found to be 0.059–0.126 ng kg−1 BW day−1 (BW: body weight), with dormitories and workplaces (i.e., laboratories and offices) accounting for over 40% and ∼50% of the ADI, respectively. The estimated hazard quotient ranged from 0.0029 to 0.0063, three orders of magnitude lower than 1, suggesting relatively low risks for college students exposed to the six PFAAs monitored in indoor dust. The analysis of dust characteristics revealed that total organic carbon did not have a significant effect on PFAAs levels as we expected. In contrast, dust moisture and cation content dominated PFAAs accumulation.

Inputs, amplification and sinks of perfluoroalkyl substances at coastal Antarctica

The sources, biogeochemical controls and sinks of perfluoroalkyl substances, such as perfluoroalkyl acids (PFAAs), in polar coastal regions are largely unknown. These were evaluated by measuring a large multi-compartment dataset of PFAAs concentrations at coastal Livingston and Deception Islands (maritime Antarctica) during three austral summers. PFAAs were abundant in atmospheric-derived samples (aerosols, rain, snow), consistent with the importance of atmospheric deposition as an input of PFAAs to Antarctica. Such PFAAs deposition was unequivocally demonstrated by the occurrence of PFAAs in small Antarctic lakes. Several lines of evidence supported the relevant amplification of PFAAs concentrations in surface waters driven by snow scavenging of sea-spray aerosol-bound PFAAs followed by snow-melting. For example, vertical profiles showed higher PFAAs concentrations at lower-salinity surface seawaters, and PFAAs concentrations in snow were significantly higher than in seawater. The higher levels of PFAAs at Deception Island than at Livingston Island are consistent with the semi-enclosed nature of the bay. Concentrations of PFOS decreased from 2014 to 2018, consistent with observations in other oceans. The sink of PFAAs due to the biological pump, transfer to the food web, and losses due to sea-spray aerosols alone are unlikely to have driven the decrease in PFOS concentrations. An exploratory assessment of the potential sinks of PFAAs suggests that microbial degradation of perfluoroalkyl sulfonates should be a research priority for the evaluation of PFAAs persistence in the coming decade.

Source, transport, and fate of perfluoroalkyl acids (PFAAs) in turbid bay environments: Significant roles of suspended sediment and water column stratification.

The coastal area was the major region receiving pollution from land-based sources into the sea. Perfluoroalkyl acids (PFAAs) in famous bays had aroused wide concern, but the importance of underdeveloped or small bays with notable levels of PFAAs were often neglected. Moreover, the roles of suspended sediment (SPS) and water column stratification on PFAA behaviors were unclear. In this study, PFAAs distribution in multiphase-multilayer in four underdeveloped bays (two urban bays and two island bays) were investigated. The urban bays not only had higher PFAA contamination but also posed a greater threat of short-chain PFAAs in water-SPS-sediment system than the island bays. The major source of PFAAs in water and SPS was domestic sewage in urban bays and was rainfall-runoff in island bays. Water column stratification with higher PFAA partition in water-SPS system in the surface layer than in the bottom layer was only found in the urban bays due to the higher human activity intensity. These provided new perspectives for managing emerging contaminants and establishing water quality criteria in the turbid coastal environment. The key role of SPS as a carrier offered possibilities to accurately differentiate the effects of dissolved and particulate PFAAs on bioavailability.

PFAS association with kisspeptin and sex hormones in teenagers of the HBM4EU aligned studies

Exposure to Perfluoroalkyl acids (PFAS) can impair human reproductive function, e.g., by delaying or advancing puberty, although their mechanisms of action are not fully understood. We therefore set out to evaluate the relationship between serum PFAS levels, both individually and as a mixture, on the Hypothalamic-Pituitary-Gonadal (HPG) axis by analyzing serum levels of reproductive hormones and also kisspeptin in European teenagers participating in three of the HBM4EU Aligned Studies. For this purpose, PFAS compounds were measured in 733 teenagers from Belgium (FLEHS IV study), Slovakia (PCB cohort follow-up), and Spain (BEA study) by high performance liquid chromatography-tandem mass spectrometry (HPLC/MS) in laboratories under the HBM4EU quality assurance quality control (QA/QC) program. In the same serum samples, kisspeptin 54 (kiss-54) protein, follicle-stimulating hormone (FSH), total testosterone (TT), estradiol (E2), and sex hormone-binding globulin (SHBG) levels were also measured using immunosorbent assays. Sex-stratified single pollutant linear regression models for separate studies, mixed single pollutant models accounting for random effects for pooled studies, and g-computation and Bayesian kernel machine regression (BKMR) models for the mixture of the three most available (PFNA, PFOA, and PFOS) were fit. PFAS associations with reproductive markers differed according to sex. Each natural log-unit increase of PFOA, PFNA, and PFOS were associated with higher TT [18.41 (6.18; 32.31), 15.60 (7.25; 24.61), 14.68 (6.18; 24.61), respectively] in girls, in the pooled analysis (all studies together). In males, G-computation showed that PFAS mixture was associated with lower FSH levels [-10.51 (−18.81;-1.36)]. The BKMR showed the same patterns observed in G-computation, including a significant increase on male Kiss-54 and SHBG levels. Overall, effect biomarkers may enhance the current epidemiological knowledge regarding the adverse effect of PFAS in human HPG axis, although further research is warranted.

Concentration, distribution, and bioconcentration of short- and long-chain perfluoroalkyl substances in the water, suspended particulate matter, and surface sediment of a typical semi-enclosed bay

This study investigated per- and polyfluoroalkyl substances (PFAS) levels in the surface water, suspended particulate matter (SPM), sediment, and fishes in the Laizhou Bay (LZB) and its inflow river estuaries in dry, normal, and wet seasons. The results demonstrated that the short-chain perfluoroalkyl acids (PFAA) accounted for about 60 % of the total PFAA (∑PFAA) concentration in water, while long-chain PFAA were the dominant compounds in the sediment and SPM. The levels of the ∑PFAA and their precursors decreased from the estuaries to the bay, which implied that terrigenous input (pollutant in land flowed into sea) was the main pollution source of PFAA in the LZB. The PFAAs levels in surface water were ranked as the order of dry > normal > wet season. The distribution coefficients of PFAA showed that the long-chain PFAA were more prone to be adsorbed by sediment and SPM than short-chain PFAA. The increase of ∑PFAA concentrations was in the range of 0.32–36.7 ng·L−1 after the oxidation conversion of water samples. Precursors were the important source of the PFAA in the surface water. The perfluorooctane sulfonate (PFOS) was the dominant compound in fish tissues. These results provide hints for understanding PFAS pollution in LZB.

Transdermal absorption of 13C4-perfluorooctanoic acid (13C4-PFOA) from a sunscreen in a male volunteer – What could be the contribution of cosmetics to the internal exposure of perfluoroalkyl substances (PFAS)?

Per- and polyfluoroalkyl substances (PFAS) are a complex group of man-made chemicals with high stability and mobility leading to ubiquitous environmental contamination and accumulation especially of some long-chain perfluoroalkyl acids (PFAA) in humans. While dietary intake is the main route of exposure, transdermal uptake from cosmetic products usually is considered negligible. However, PFAS are present in a part of these products, and recent epidemiological studies have provided evidence for relevant uptake via this route. The crucial question is whether PFAA in cosmetic products can cross the human skin barrier. A defined amount (110 µg) of 13C4-perfluorooctanoic acid (13C4-PFOA) was mixed into a sunscreen (30 g) which was applied on the whole skin of a volunteer. The plasma concentrations of 13C4-PFOA were determined in serial blood samples taken over 115 days using UHPLC-MS/MS and 13C2-PFOA as internal standard. After application, 13C4-PFOA plasma levels increased continuously, reaching levels of 3, 56 and 118 ng/L after 6 h, 3 days and 10 days, respectively. A maximum level of 132 ng/L was measured 22 days after application, representing 9.4 % of the PFOA level resulting from the volunteer’s background exposure (1400 ng/L, equivalent to 1.4 ng/mL). In the following weeks, the levels slightly decreased with an estimated half-life of 1.8 years. The best estimate for the fraction absorbed may be 1.6 % of the dose, using a volume of distribution of 0.17 L/kg body weight. For PFOA mixed into a sunscreen, this experimental approach demonstrates a significant uptake of a PFAA via transdermal absorption in humans. In the past, some cosmetic products contained relevant PFAA levels as contaminants/impurities of PFAS added as active ingredients. Depending on these levels and the use (frequency, skin area involved), it is plausible that this route of exposure has contributed to the internal exposure to PFAA, as already suggested by epidemiological observations.

Elevated exposure to long-chain perfluoroalkyl and polyfluoroalkyl substances (PFAS) in Inuit from Nunavik, Arctic Canada: a call for global action

BACKGROUND AND AIM: The Inuit of Nunavik are exposed to perfluoroalkyl acids (PFAAs) via long-rang transport from southern to northern latitudes and biomagnification of PFAAs in Arctic food webs. Our objective was to document plasma PFAAs levels and compare them to previously documented levels and the general Canadian population. METHODS: The study included 1326 Nunavimmiut aged 16-82 years from the population representative survey, Qanuilirpitaa? 2017 Nunavik Inuit Health Survey. Concentrations of nine PFAAs were assessed, including perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate (PFHxS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA) and perfluoroundecanoic acid (PFUdA). Concentrations were compared to Nunavik levels in 2004, other Arctic regions, and the Canadian Health Measures Survey (CHMS) Cycle 5 2016-2017. Multiple linear regression analyses compared concentrations by demographics and lifestyle. RESULTS: There were elevated concentrations of various PFAAs congeners compared to CHMS, including PFOS, and long-chain PFAS congeners, PFNA, PFDA, and PFUnDA. PFNA and PFUdA concentrations were 7-fold higher than the CHMS concentrations, and PFDA concentrations were almost 4-fold higher than the CHMS concentrations. Short-chain congeners were largely undetected. Concentrations differed by sex, age, region, and indicators of seafood and marine mammal consumption. Males had higher concentrations of PFOA and PFHxS, whereas females had higher concentrations of PFDA and PFUdA. PFAAs concentrations increased with age and were highest among those aged 50+ years, such that serum PFOS concentrations were 2.5 times higher in those aged 50+ years compared to those aged 16-29 years. PFNA concentrations followed a U-shaped curve with increasing age. CONCLUSIONS: Our findings indicate a decrease in older PFAAs, but concentrations of many PFAAs in Nunavik remain several-fold higher compared to the general Canadian population. Evidence also points to an increase in exposure to long-chain PFAAs, which are an emerging public health concern in the Arctic. KEYWORDS: PFAS, Indigenous, Environmental justice, Exposure

Fatty acid ecological tracers highlight the role of diet in perfluoroalkyl acid contaminant exposure in eggs of an omnivorous bird

Herring gulls (Larus argentatus) are generalist feeders; contaminant levels in their eggs reflect chemical exposure and uptake due to foraging in both aquatic and terrestrial environments. Hence, contaminant levels in their eggs provide insights into sources and relative importance of aquatic versus terrestrial pathways of chemical transfer. Here, perfluoroalkyl acids (PFAAs) known to be bioaccumulative were measured in individual herring gull eggs from one site on Lake Superior, Ontario, Canada. Thirteen perfluorinated carboxylates (PFCA, C4-C18) and four perfluorinated sulfonates (PFSA, C4-C10) were measured. Total PFCA and total PFSA concentrations varied 4- and 5-fold, respectively, among eggs. To understand these differences, stable carbon and nitrogen isotopes and fatty acid dietary tracers were measured in the same eggs. Stable isotopes were not useful in explaining inter-egg differences in PFAA concentrations. However, a variety of omega 3 (n-3) and omega 6 (n-6) fatty acid measures were correlated with C9-C13 PFCAs as well as the PFSAs: perfluoro-1-hexanesulfonic acid (PFHxS) and perfluoro-1-octanesulfonic acid (PFOS). In general, n-3 fatty acids were positively correlated with egg PFAA concentrations while only the n-6 fatty acids exhibited negative relationships with egg PFAA levels. Proportions of n-3 and n-6 fatty acids in eggs would be expected to increase and decrease, respectively, with increased aquatic food in the gull diet. Results indicate that increased use of aquatic food led to heightened PFAA exposure in these generalist consumers sampled in a relatively remote area. They also highlight the utility of employing a variety of dietary markers for understanding contaminant exposure and accumulation.

Outside the Safe Operating Space of a New Planetary Boundary for Per- and Polyfluoroalkyl Substances (PFAS).

It is hypothesized that environmental contamination by per- and polyfluoroalkyl substances (PFAS) defines a separate planetary boundary and that this boundary has been exceeded. This hypothesis is tested by comparing the levels of four selected perfluoroalkyl acids (PFAAs) (i.e., perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorohexanesulfonic acid (PFHxS), and perfluorononanoic acid (PFNA)) in various global environmental media (i.e., rainwater, soils, and surface waters) with recently proposed guideline levels. On the basis of the four PFAAs considered, it is concluded that (1) levels of PFOA and PFOS in rainwater often greatly exceed US Environmental Protection Agency (EPA) Lifetime Drinking Water Health Advisory levels and the sum of the aforementioned four PFAAs (Σ4 PFAS) in rainwater is often above Danish drinking water limit values also based on Σ4 PFAS; (2) levels of PFOS in rainwater are often above Environmental Quality Standard for Inland European Union Surface Water; and (3) atmospheric deposition also leads to global soils being ubiquitously contaminated and to be often above proposed Dutch guideline values. It is, therefore, concluded that the global spread of these four PFAAs in the atmosphere has led to the planetary boundary for chemical pollution being exceeded. Levels of PFAAs in atmospheric deposition are especially poorly reversible because of the high persistence of PFAAs and their ability to continuously cycle in the hydrosphere, including on sea spray aerosols emitted from the oceans. Because of the poor reversibility of environmental exposure to PFAS and their associated effects, it is vitally important that PFAS uses and emissions are rapidly restricted.

Evaluated serum perfluoroalkyl acids and their relationships with the incidence of rheumatoid arthritis in the general population in Hangzhou, China

Perfluoroalkyl acids (PFAAs) are widely present in human blood, and have many toxic effects on humans. However, effects of PFAA exposure on the risk of rheumatic immune diseases are limited. In the present study, occurrence of 7 PFAAs, including perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoate (PFNA), perfluorodecanoate (PFDA), perfluoroundecanoate (PFUnA), perfluorododecanoate (PFDoA), and perfluorotrdecanoate (PFTrA), were measured in serum samples from 156 healthy people (controls) and 156 rheumatoid arthritis (RA) cases living in Hangzhou, China. We also investigated the relationships among cumulative PFAA levels in serum, some immune markers, and the incidence of RA. The results showed that PFOA (6.1 and 11.8 ng/mL) had the highest mean serum concentrations, followed by PFOS (3.2 and 3.4 ng/mL) and PFDA (0.86 and 2.6 ng/mL), in both controls and RA cases. Cumulative exposure to PFOA in the study population were positively correlated with the levels of rheumatoid factors (rs = 0.69, p < 0.01) and anti-cyclic citrullinated peptide antibody (rs = 0.56, p < 0.05). Moreover, significant associations of PFOA concentrations with odds ratios (OR) of RA (OR = 1.998, confidence interval (CI): 1.623, 2.361, p = 0.01) were found by adjusting for various covariates. The crude and adjusted OR for RA was respective 1.385 (95% CI: 1.270, 1.510, p = 0.04) and 1.381 (95% CI: 0.972, 1.658, p = 0.06) for a unit increase in serum PFOS levels, but the adjusted results were not significant. Overall, this case-control study found that human serum PFOA concentrations were positively correlated with RF and ACPA levels.

Spatiotemporal distribution of perfluoroalkyl acid in Chinese eggs

ABSTRACT To study the contamination levels of perfluoroalkyl acids (PFAAs) in Chinese eggs and the effects of persistent organic pollutant (POP) amendments to the Stockholm Convention blacklist, 3200 eggs from 10 major producing areas were collected from June 2013 to May 2017. Seventeen PFAAs in eggs were analysed. Perfluorooctane sulphonic acid (PFOS), perfluoropentanoic acid (PFPeA) and perfluorooctanoic acid (PFOA) were the main PFAAs in eggs. Perfluoroalkyl carboxylic acids (PFCAs) and short-chain PFAAs levels in eggs decreased after the amendment was implemented in China (p < .05), but no significant difference was observed in PFOS. The average ΣPFAAs of eggs from 10 major producing areas was 0.23 ng/g (<LOD–5.4 ng/g), with samples from Hunan, Hubei and Henan being above this threshold, indicates the need for more stringent evaluation and regulation on pollutant management practices. The detection rate of eggs with PFOS risk was very low and no consumption-related health risk was identified.

Emerged macrophytes to the rescue: Perfluoroalkyl acid removal from wastewater and spiked solutions

This study evaluated the potential for three emergent aquatic macrophytes to remove perfluoroalkyl acids (PFAAs) from contaminated waters in constructed wetland systems. Three plants (Iris pseudacorus L., Phragmites australis (Cav.) Trin. Ex Steud., and Typha latifolia L.) were exposed to an effluent from a tannery wastewater treatment plant (WWTP) that contained residual PFAAs, and to three spiked solutions with increasing concentrations of 11 perfluorocarboxylic acids (PFCAs) and three perfluorosulfonic acids (PFSAs) (500, 2500, and 5000 ng L−1, each). Thirty-six lightweight expanded clay aggregate- and vegetation-filled tanks (0.35 × 0.56 × 0.31 m) were exposed to the tested solutions at the Acque del Chiampo SpA WWTP in Arzignano (NE Italy). Throughout the experiment, PFAA concentrations and physicochemical water parameters were monitored via measures of the clay material, plastic tank inner surfaces, and below- and above-ground biomasses (after harvest). Vegetation growth was shown to be unaffected by increased PFAA levels in the spiked solutions. Alternatively, total biomass was significantly reduced when WWTP water was used, although we attribute this finding to the relatively high salinity that mainly restricted Typha and Iris development. The tested macrophytes were found to remove a significant PFAA mass from the contaminated waters (36% to ca. 80%, on average) when Phragmites was subjected to the highest PFAA concentrations. Such large accumulations were primarily associated with long C-chain PFAA stabilization in belowground biomass (26%, on average). Most PFAA translocations were observed in Typha, which accumulated mostly short perfluorinated C-chain PFBA, PFPeA, and PFHxA in the aboveground biomass (16%, on average). Despite some growth limitations, Iris was still the most efficient macrophyte for translocating PFBS under WWTP.

Shift in the distribution and fate of perfluoroalkyl acids by sluice gates in the multi-environment media of rivers

The impact of sluice operations on the distribution and fate of perfluoroalkyl acids (PFAAs) remains poorly understood. In this study, the distribution of PFAAs was investigated in water, suspended particles, sediment, and pore water from the upstream and downstream sections of six sluice gates along the Wangyu River, China. The target PFAAs were widely distributed in the dissolved phase (∑PFAAs: 447.61 ± 180.26 ng/L), particle phase (∑PFAAs: 2040.95 ± 1870.88 ng/g dw), sedimentary phase (∑PFAAs: 39.42 ± 35.38 ng/g dw), and pore water phase (∑PFAAs: 8172.54 ± 4278.60 ng/L). Our data suggest predominant detections of short-chain PFAAs such as perfluorobutanoic acid (PFBA) and perfluorohexanoic acid (PFHxA) in the four environmental media. Sediment pore water appeared as an essential repository and potential source for PFAA re-release to the river environment. The levels of PFAAs in the dissolved and suspended particle phase upstream of the sluices were significantly lower than those downstream, while the situation in the sediment and pore water phase was the opposite. Sluice operation caused PFAA redistribution among the multi-environment media but did not change the PFAA composition, which had the significant effect on the partition behavior of perfluoroalkyl carboxylic acids (PFCAs) between particles and water, as well as changed the migration pattern of PFOA, PFNA and PFOS from equilibrium to the migration state. Quantitative prediction models were developed for simulating fate of PFAAs in gate-controlled river, and the major factors affecting the distribution and fate of PFAAs were identified. Our findings provide insights into the redistribution mechanisms of PFAAs and an understanding of their environmental fate.

The Impact of Smoking on the Association between Perfluoroalkyl Acids (PFAS) and Thyroid Hormones: A National Health and Nutrition Examination Survey Analysis.

Perfluoroalkyl acids (PFAS) are known endocrine disrupting chemicals, potentially affecting thyroid function. Smoking has been associated with PFAS levels as well as with thyroid function. The impact of smoking on the association between PFAS and thyroid function remains to be elucidated, so the objective was to assess the effect of PFAS exposure on thyroid function in the general population, stratified by smoking status, using the National Health and Nutrition Examination Survey (NHANES). NHANES adult participants who were part of the 2011–2012 laboratory subsample and had PFAS and thyroid function measured were included (n = 1325). Adjusted linear regression models and stratified analyses were performed. There was a significant positive association between perfluorooctanesulfonic acid (PFOS) (p = 0.003), perfluorononanoic acid (PFNA) (p = 0.014), total PFAS (p = 0.004) concentrations and free T4 (FT4). No significant associations were found between perfluorooctanoic acid (PFOA), PFOS, perfluorohexane sulfonate (PFHxS), PFNA, total PFAS and total T4 (TT4) or thyroid stimulating hormone (TSH). In non-smokers, a significant positive association was found between PFOS (p = 0.003), PFHxS (p = 0.034), PFNA (p = 0.012), total PFAS (p = 0.003) and FT4 while no significant associations were found in smokers. The present study showed that increased PFAS exposure was associated with increased FT4 in non-smokers, while no association was found in smokers. These results confirm that smoking modifies the association between PFAS exposure and thyroid function.