Perfluoroalkyl Substances Research Articles

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).

Effect of high-frequency ultrasonication on degradation of polytetrafluoroethylene (PTFE) microplastics/nanoplastics

Polytetrafluoroethylene (PTFE) particle might present a significant contamination in environment due to its dual classification as a microplastic and a fluorinated compound (a type of PFAS, or per- and polyfluoroalkyl substances), coupled with its extreme stability. Identifying an effective degradation method for PTFE microplastics is thus crucial towards remediation, along with the suitable monitoring approaches. This study is the first to use high-frequency (580 kHz) ultrasonication for the degradation of the PTFE microplastics with diameter of ∼1000 nm. Dispersion of PTFE microplastics with help of surfactant (SDS, or sodium dodecyl sulfate) followed by ultrasonication for 9 h under optimal conditions resulted in a defluorination percentage of ∼32 %. Particle size analysis demonstrated the effective diameter shrink of PTFE microplastics by ultrasonication (from ∼1000 nm to ∼330 nm that can be categorized as nanoplastics). SEM-EDS provided clear visualization of PTFE microplastics/nanoplastics, while Raman imaging confirmed the fine particles from molecular spectrum window. ImageJ analysis algorithms were utilized to estimate particle sizes as well. Based on these findings, a potential degradation mechanism for PTFE microplastics/nanoplastics was proposed. This study contributes to the understanding of PTFE degradation and may facilitate further research in this field.

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.

A novel high-throughput quantitative method for the determination of per- and poly-fluoroalkyl substances in human plasma based on UHPLC-Q/Orbitrap HRMS coupled with isotope internal standard

A novel high-throughput quantitative method for the determination of per- and poly-fluoroalkyl substances in human plasma based on UHPLC-Q/Orbitrap HRMS coupled with isotope internal standard

Transition-metal-free defluorinative cyclization of perfluoroalkyl alkenyl iodides with C,N-dinucleophiles: Synthesis of (E)-perfluoroalkenyl pyrroles

Functionalization of the C-F bond in perfluoroalkyl substances represents an emerging focus in organic chemistry. We report here a transition-metal-free intermolecular defluorinative cyclization of perfluoroalkyl alkenyl iodides with C,N-dinucleophiles. This method enables highly chemo-, regio-, and stereoselective 2-fold C (sp3)-F bond cleavage at two vicinal carbon centers in the perfluoroalkyl chain, resulting in the assembly of a five-membered N-heterocycle with a structurally privileged (E)-prefluoroalkenyl unit. The success of partial defluorination is mainly attributed to the pre-installed alkenyl functionality and iodide atom in perfluoroalkyl substances.

Integration of vacuum UV/peroxydisulfate and reductive processes for the thorough defluorination of 8:3 fluorotelomer carboxylates: The critical contribution of preoxidation

Fluorotelomers have been systematically developed in bulk quantities and extensively applied in the fluoropolymer industry. Reductive treatments of fluorotelomers are different from those of perfluoroalkyl substances. In this study, vacuum UV/peroxydisulfate (VUV/PDS) was used for the first time to preoxidize 8:3 fluorotelomer carboxylates (8:3FTCA). Subsequently, it was integrated with the VUV/sulfite/iodide reductive process to accomplish the comprehensive defluorination of the oxidized products. The performance and mechanisms of 8:3FTCA degradation in the preoxidation process were mainly explored. pH values from 6.0 to 8.0 were conducive to 8:3FTCA decomposition. Hydrogen peroxide, hydroxyl radical (•OH), and hydroperoxyl radical (HO2•) were observed to be in a dynamic equilibrium state of mutual transformation, and the contributions of •OH and HO2• were 76.8 % and 17.4 %, respectively. The investigation of the influences of background water matrices demonstrated minimal adverse effects of sulfate and chloride, whereas bicarbonate, carbonate, and natural organic matter exhibited inhibitory effects. The degradation pathways of 8:3FTCA were speculated through density functional theory calculation and intermediate identification. The Ecological Structure–Activity Relationships simulation showed that VUV/PDS preoxidation decreased the aquatic toxicity of 8:3FTCA. These findings provide valuable insights for addressing challenges associated with fluorotelomer carboxylates.

Association of perfluoroalkyl substances (PFAS) with liver function biomarkers in the highly exposed population of the veneto region

IntroductionEpidemiological studies highlight the presence of associations between per- and polyfluoroalkyl substances (PFAS) exposure with liver damage. In 2013, PFAS contamination was discovered in Veneto (Italy), leading to the implementation of a Surveillance Program (SP). Our objective is to investigate the association between PFAS exposure and biomarkers of liver function using single-pollutant and mixture approaches, while exploring the sex-specific differences and the mediating role of obesity in the association. MethodsThe study included 42,094 subjects aged ≥20 years participating in the SP. We used generalized additive models to investigate the association between several PFAS and alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, adjusting for possible confounders and stratifying by sex. Results were back-transformed to show predicted percentage changes in outcomes per ln-unit increase in PFAS levels; furthermore, we explored the role of BMI in the abovementioned causal pathway, considering it as a potential confounder or mediator PFAS joint effect was investigated using Quantile G-computation. ResultsOne ln-unit increase in PFHxS concentrations was associated with a 1.49% (95%CI: 0.87, 2.12) and a 0.84% (95% CI: 0.27, 1.40) increase in ALT levels, in males and females respectively; one ln-unit increase in PFOA concentrations was associated with a 1.03% (95%CI: 0.50, 1.55) increase in ALT levels in males, and a 0.52% (95% CI: 0.22, 0.82) and a 0.60% (95% CI: 0.25, 0.96) increase in AST levels in females and males. PFOS showed no association with ALT and AST levels. Quantile G-computation revealed that an interquartile increase in the PFAS mixture was associated with a 3.02% increase (95% CI: 1.65, 4.43) and a 1.65% (95% CI: 0.77, 2.5) increase in ALT levels, in females and males. Mediation analysis suggested that BMI suppressed the association between PFAS and ALT levels, with positive direct effects higher than the total effects. ConclusionOur findings suggest sex-specific associations between PFAS exposure and liver function biomarkers and underscore the need for additional studies on potential mediators.

Tissue distribution and temporal and spatial assessment of per- and polyfluoroalkyl substances (PFAS) in smallmouth bass (Micropterus dolomieu) in the mid-Atlantic United States

Per- and polyfluoroalkyl substances (PFAS) have become an environmental issue worldwide. A first step to assessing potential adverse effects on fish populations is to determine if concentrations of concern are present in a region and if so, in which watersheds. Hence, plasma from adult smallmouth bass Micropterus dolomieu collected at 10 sites within 4 river systems in the mid-Atlantic region of the United States, from 2014 to 2019, was analyzed for 13 PFAS. These analyses were directed at better understanding the presence and associations with land use attributes in an important sportfish. Four substances, PFOS, PFDA, PFUnA, and PFDoA, were detected in every plasma sample, with PFOS having the highest concentrations. Sites with mean plasma concentrations of PFOS below 100 ng/ml had the lowest percentage of developed landcover in the upstream catchments. Sites with moderate plasma concentrations (mean PFOS concentrations between 220 and 240 ng/ml) had low (< 7.0) percentages of developed land use but high (> 30) percentages of agricultural land use. Sites with mean plasma concentrations of PFOS > 350 ng/ml had the highest percentage of developed land use and the highest number PFAS facilities that included military installations and airports. Four of the sites were part of a long-term monitoring project, and PFAS concentrations of samples collected in spring 2017, 2018, and 2019 were compared. Significant annual differences in plasma concentrations were noted that may relate to sources and climatic factors. Samples were also collected at two sites for tissue (plasma, whole blood, liver, gonad, muscle) distribution analyses with an expanded analyte list of 28 PFAS. Relative tissue distributions were not consistent even within one species of similar ages. Although the long-chained legacy PFAS were generally detected more frequently and at higher concentrations, emerging compounds such as 6:2 FTS and GEN X were detected in a variety of tissues.

Eco-environmental responses of Eichhornia crassipes rhizobacteria community to co-stress of per(poly)fluoroalkyl substances and microplastics

The stabilization of rhizobacteria communities plays a crucial role in sustaining healthy macrophyte growth. In light of increasing evidence of combined pollution from microplastics (MPs) and per- and polyfluoroalkyl substances (PFASs), Selecting typical floating macrophyte as a case, this study explored their impacts using hydroponic simulations and 16S rRNA high-throughput sequencing. A total of 31 phyla, 77 classes, 172 orders, 237 families, 332 genera, and 125 rhizobacteria species were identified. Proteobacteria (16.19% to 57.70%) was the dominant phylum, followed by Bacteroidota (12.34% to 44.48%) and Firmicutes (11.31% to 36.36%). In terms of α-diversity, polystyrene (PS) MPs and PFASs significantly impacted community abundance (ACE and PD-tree) rather than evenness (Shannon and Pielou) compared to the control. βMNTD and βNTI analyses revealed that PS MPs enhanced deterministic assembly processes driven by F-53B and GenX, while mitigating those induced by PFOA and PFOS. Contamination treatments narrowed the ecological niche breadths at both the phylum (5% (PS) to 49.91% (PS & PFOA)) and genus levels (8% (PS) to 63.96% (PS & PFOA)). Functionally, MPs and PFASs decreased the anaerobic capacity and ammonia nitrogen utilization of rhizosphere bacteria. This study enhances our understanding of the microecological responses of macrophyte-associated bacteria to combined MP and PFAS contamination and offers insights into ecological restoration strategies and mitigating associated environmental risks.

Cation-Doped Nanocarbons for Enhanced Perfluoroalkyl Substance Removal: Exotic Bottom-Up Solution Plasma Synthesis and Characterization.

Perfluorinated alkyl substances (PFAS), such as perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), are pervasive organic contaminants that are widespread in aquatic environments, posing significant health risks to humans and wildlife. Due to their persistent nature, urgent removal is necessary. Conventional adsorbents are inefficient at removing PFOS and PFOA, highlighting the need for alternative materials. Herein, we present a synthetic method for quaternary ammonium cation-doped carbon nanoparticles (QACNs) using a solution plasma process for the efficient removal of PFOS and PFOA. QACN is formed simultaneously through a one-step discharge of nonequilibrium plasma at the interface of benzene and pyridinium chloride. The resulting material exhibited a high surface electrical charge and enhanced hydrophilicity as well as an amorphous structure of a nonporous nature, involving nanoparticles with an undefined shape. The obtained adsorbent demonstrated high adsorption efficiency and stability, adsorbing 998.45 and 889.37 mg g-1 of PFOS and PFOA, respectively, exceeding the efficiencies of conventional carbon-based adsorbents (80.89-313.15 mg g-1). The adsorption performance was dependent on the adsorbent dosage, pH of the solution, and the coexisting ionic species. Adsorption studies, including adsorption kinetics, isotherms, and thermodynamics, revealed that PFOS and PFOA were chemisorbed to the QACN surface, forming multilayers endothermically and spontaneously. Experimental and computational analyses revealed that adsorption primarily occurs via electronic interactions between the PFAS active sites and the quaternary ammonium group in the carbon framework. The slightly lower adsorption potential of the PFOS and PFOA fluorocarbon chains on the adsorbent was elucidated. Furthermore, the dispersibility of the adsorbent in solution significantly affected the adsorption performance. These findings highlight the potential of the novel synthetic method proposed in this study, offering a pathway for the development of highly effective carbon adsorbents for environmental remediation.

Breast Cancer-Related Chemical Exposures in Firefighters.

To fill a research gap on firefighter exposures and breast cancer risk, and guide exposure reduction, we aimed to identify firefighter occupational exposures linked to breast cancer. We conducted a systematic search and review to identify firefighter chemical exposures and then identified the subset that was associated with breast cancer. To do this, we compared the firefighter exposures with chemicals that have been shown to increase breast cancer risk in epidemiological studies or increase mammary gland tumors in experimental toxicology studies. For each exposure, we assigned a strength of evidence for the association with firefighter occupation and for the association with breast cancer risk. We identified twelve chemicals or chemical groups that were both linked to breast cancer and were firefighter occupational exposures, including polycyclic aromatic hydrocarbons, volatile aromatics, per- and polyfluoroalkyl substances, persistent organohalogens, and halogenated organophosphate flame retardants. Many of these were found at elevated levels in firefighting environments and were statistically significantly higher in firefighters after firefighting or when compared to the general population. Common exposure sources included combustion byproducts, diesel fuel and exhaust, firefighting foams, and flame retardants. Our findings highlight breast-cancer-related chemical exposures in the firefighting profession to guide equitable worker's compensation policies and exposure reduction.

Integrating redox-electrodialysis and electrosorption for the removal of ultra-short- to long-chain PFAS

A major challenge in per- and polyfluoroalkyl substances (PFAS) remediation has been their structural and chemical diversity, ranging from ultra-short to long-chain compounds, which amplifies the operational complexity of water treatment and purification. Here, we present an electrochemical strategy to remove PFAS from ultra-short to long-chain PFAS within a single process. A redox-polymer electrodialysis (redox-polymer ED) system leverages a water-soluble redox polymer with inexpensive nanofiltration membranes, facilitating the treatment of varied chain lengths of PFAS without membrane fouling. Our approach combines both ion migration by electrodialysis (for PFAS with chain lengths ≤C4) and electrosorption strategies (for PFAS with chain lengths ≥C6) to eliminate approximately 90% of ultra-short-, short-chain, and long-chain PFAS. At the same time, we achieve continuous desalination of the source water down to potable water level. The redox-polymer ED exhibits remarkable PFAS removal in real source water scenarios, including from matrices with 10,000 times higher salt concentrations, as well as secondary effluents from wastewaters. Additionally, the removed PFAS is mineralized with a defluorination performance between 76-100% by electrochemical oxidation, highlighting the viability of integrating the separation step with a reactive degradation process.

Fluoropolymer sorbent for efficient and selective capturing of per- and polyfluorinated compounds

Per- and poly-fluoroalkyl substances (PFAS) have gained widespread attention due to their adverse effects on health and environment. Developing efficient technology to capture PFAS from contaminated sources remains a great challenge. In this study, we introduce a type of reusable polymeric sorbent (PFPE-IEX + ) for rapid, efficient, and selective removal of multiple PFAS impurities from various contaminated water sources. The resin achieves >98% removal efficiency ([PFPE-IEX + ] = 0.5–5 mg mL−1, [PFAS]0 = 1–10 ppb in potable water and landfill leachate) and >500 mg g−1 sorption capacity for the 11 types of examined PFAS. We achieve efficient PFAS removal without breakthrough and subsequent resin regeneration and demonstrate good PFAS recovery in a proof-of-concept cartridge setup. The outcomes of this study offer valuable guidance to the design of platforms for efficient and selective PFAS capture from contaminated water, such as drinking water and landfill leachate.

Skin Permeability of Perfluorocarboxylic Acids Using Flow-Through Diffusion on Porcine Skin.

Per- and polyfluoroalkyl substances (PFAS) are found in a variety of places including cosmetics, rain jackets, dust, and water. PFAS have also been applied to occupational gear to protect against water and oils. However, PFAS have been identified as immunosuppressants and perfluorooctanoic acid (PFOA), a specific PFAS, has been identified as carcinogenic. Since there is a risk for dermal exposure to these compounds, there is a need to characterize their dermal absorption. Using in vitro flow-through diffusion, skin permeabilities were determined for 14C-labeled perfluorooctanoic acid (PFOA), perfluorohexanoic acid (PFHxA), and perfluorobutanoic acid (PFBA) using porcine skin. Tests were conducted over 8 h with either acetone or artificial perspirant as the vehicle. PFBA was found to have greater permeability than PFHxA, likely due to having a smaller molecular weight. The dosing vehicle did not appear to impact permeability rates but impacted the disposition through the skin model. While these PFAS compounds showed a low permeability rate through the skin membranes, they can stay in the skin, acting as a reservoir.

In vitro and in silico characterization of the transport of selected perfluoroalkyl carboxylic acids and perfluoroalkyl sulfonic acids by human organic anion transporter 1 (OAT1), OAT2 and OAT3

Perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFSAs) belong to the group of poly- and perfluoroalkyl substances (PFASs), which may accumulate in humans due to their limited excretion. To provide more insight into the active renal excretion potential of PFASs in humans, this work investigated in vitro the transport of three PFCAs (PFHpA, PFOA, PFNA) and three PFSAs (PFBS, PFHxS and PFOS) using OAT1-, OAT2- or OAT3-transduced human embryonic kidney (HEK) cells. Only PFHpA and PFOA showed clear uptake in OAT1-transduced HEK cells, while no transport was observed for PFASs in OAT2-transduced HEK cells. In OAT3-transduced HEK cells only PFHpA, PFOA, PFNA, and PFHxS showed clear uptake. To study the interaction with the transporters, molecular docking and dynamics simulation were performed for PFHpA and PFHxS, for which a relatively short and long half-life in humans has been reported, respectively. Docking analyses could not always distinguish the in vitro transported from the non-transported PFASs (PFHpA vs. PFHxS), whereas molecular dynamic simulations could, as only a stable interaction of the PFAS with the inner part of transporter mouth was detected for those that were transported in vitro (PFHpA with OAT1, none with OAT2, and PFHpA and PFHxS with OAT3). Altogether, this study presents in vitro and in silico insight with respect to the selected PFASs transport by the human renal secretory transporters OAT1, OAT2, and OAT3, which provides further understanding about the differences between the capability of PFAS congeners to accumulate in humans.

Elucidating per- and polyfluoroalkyl substances (PFASs) soil-water partitioning behavior through explainable machine learning models

In this study, an optimized random forest (RF) model was employed to better understand the soil-water partitioning behavior of per- and polyfluoroalkyl substances (PFASs). The model demonstrated strong predictive performance, achieving an R2 of 0.93 and an RMSE of 0.86. Moreover, it required only 11 easily obtainable features, with molecular weight and soil pH being the predominant factors. Using three-dimensional interaction analyses identified specific conditions associated with varying soil-water partitioning coefficients (Kd). Results showed that soils with high organic carbon (OC) content, cation exchange capacity (CEC), and lower soil pH, especially when combined with PFASs of higher molecular weight, were linked to higher Kd values, indicating stronger adsorption. Conversely, low Kd values (< 2.8 L/kg) typically observed in soils with higher pH (8.0), but lower CEC (8 cmol+/kg), lesser OC content (1 %), and lighter molecular weight (380 g/mol), suggested weaker adsorption capacities and a heightened potential for environmental migration. Furthermore, the model was used to predict Kd values for 142 novel PFASs in diverse soil conditions. Our research provides essential insights into the factors governing PFASs partitioning in soil and highlights the significant role of machine learning models in enhancing the understanding of environmental distribution and migration of PFASs.

Contamination of Perfluoroalkyl Substances and Environmental Fight for Safe and Health: The MammeNoPfas Movement as Epistemic Community

Contamination of Perfluoroalkyl Substances and Environmental Fight for Safe and Health: The MammeNoPfas Movement as Epistemic Community

Unraveling drivers of per- and polyfluoroalkyl substances (PFASs) occurrence and removal in leachate: Insights from disposal methods, geo-climate, and biodegradation

Leachate is a substantial reservoir of per- and polyfluoroalkyl substances (PFASs) within the environment. However, comprehensive information on the occurrence and fate of PFASs in leachate, particularly in semi-arid and moderate-elevation regions where PFASs may aggregate, is lacking. Here, 13 legacy PFASs were investigated in leachate from landfills and an incineration plant in such area. PFASs concentrations ranged from 6063 to 43,161 ng·L−1 in raw leachate, influenced by leachate origin, climate, wastewater disposal, and especially bacterial communities. Bacteroidetes and Firmicutes were enriched in raw leachate, while Proteobacteria dominated during leachate treatment processes, possibly due to PFASs selection pressure. In addition, top 20 biomarkers indicated the potential of these bacterial indicators for PFASs detection. Tracing analysis also suggested that PFASs in groundwater may have originated from leachate and effluent from wastewater treatment plants. PFASs levels in groundwater showed a significant correlation with the presence of Brevundimonas, Leptothrix, Malikia, and Sphaerotilus. The pathogenic bacterium Brevundimonas suggested potential human health risks, while Leptothrix, Malikia, and Sphaerotilus may serve as indicators of groundwater contamination. This study is believed to provide insights into how to prevent and control PFASs-related environmental pollution.

Prenatal exposure to per- and polyfluoroalkyl substances, genetic factors, and autistic traits: Evidence from the Shanghai birth cohort

The epidemiological evidence regarding prenatal PFAS exposure and its interaction with genetic factors on the autistic traits risk is unclear. This study included 1610 mother-child pairs from the Shanghai Birth Cohort (SBC). Ten PFAS were quantified in blood serum collected in the first trimester. Child autistic traits were evaluated at age 4 using a Chinese version of the social responsiveness scale-short form (SRS-SF). We calculated the polygenic risk score (PRS) to evaluate the cumulative genetic effects of autism. Additive interaction models were established to explore whether genetic susceptibility modified the effects of prenatal PFAS exposure. After adjusting for confounders, we found prenatal PFOA exposure was associated with an increased risk of autistic traits in children (OR, 3.05; 95 % CI, 1.14–7.58), and the increased risk associated with PFOA was mitigated among women who reported pre-pregnancy folic acid supplementation. Additionally, an increased risk of autistic traits was observed in children with higher levels of prenatal PFHxS exposure and a high PRS (p for interaction = 0.021). Our findings suggest prenatal PFAS exposure may increase the risk of autistic traits in children, especially in those with a high genetic risk. Further research is warranted to confirm this association and explore the underlying mechanisms.

Environmental contaminants, sex hormones and SHBG in an elderly population

IntroductionEffects of environmental contaminants (ECs) on endocrine systems have been reported, but few studies assessed associations between ECs and sex hormones (SH) in elderly. Aim of this study was to investigate whether blood concentrations of four classes of ECs were associated with SH concentrations in elderly. MethodsSamples from participants of the cross-sectional population-based Prospective Investigation of the Vasculature in Uppsala Seniors study (PIVUS, 70-year-old men and women, n = 1016) were analyzed using validated mass spectrometry-based methods for SH (testosterone (T), dihydrotestosterone (DHT), estrone and estradiol (E2)); 23 persistent organic pollutants (POPs); 8 perfluoroalkyl substances (PFAS); 4 phthalates and 11 metals. SH binding globulin (SHBG) was analyzed using immunoassay. The measured concentrations were normalized, and the values converted to a z-scale. Linear regression analyses were conducted to assess association between concentration of the SH, SHBG and E2/T (aromatase enzyme index, AEI) with the ECs. Multiple linear regression analyses were performed to model the relationships. ResultsThe strongest associations were observed with the polychlorinated biphenyls (PCBs). In men, the strongest associations with concentrations of SH and SHBG were seen for PCBs containing >5 chlorine, monoethyl phthalate (MEP), Ni and Cd; and in women, with PCBs, MEP, several of the PFAS, Cd, Co, and Ni. Difference in the effect of ECs on AEI between men and women were observed. Area under the ROC curve for the models predicting abnormal values of SH and SHBG >0.75 due to the effects of ECs was observed for T, DHT, and E2 in men, and for E2 and SHBG in women. ConclusionsResults of this study suggest that in elderly subjects, concentrations of many ECs associated with concentrations of SH and SHBG, and AEI. Further studies are needed to confirm the findings and to assess effect of the pollutants on endocrine system function in elderly.