Higher PFOS Research Articles

Investigating hydrodynamic cavitation as an efficient means for removal of per- and polyfluoroalkyl substances from solution

With nearly five decades of per- and polyfluoroalkyl substances (PFASs) being associated with firefighting and industrial activities, these compounds inevitably accumulate in both ground and surface water. PFAS contamination in water has emerged as a significant environmental and public health concern, particularly perfluorooctanesulfonic acid (PFOS), which is often found in higher concentrations compared to other PFAS and has more pronounced adverse health effects. Addressing PFAS contamination requires treating large volumes of water, making technologies that rapidly separate and concentrate PFASs highly favoured. The strong surface activity of PFAS, such as PFOS, enables them to generate colloidal gas aphrons (CGAs) during high shear mixing of their aqueous solutions, where PFASs can be separated and collected as foam. This study aims to evaluate the effectiveness of high shear mixing in separating PFOS from solution, leveraging its accumulation at air–water interfaces. High shear-assisted PFOS separation was tested by varying parameters like rotational speed (4000 to 10,000 rpm), mixing time (30 s to 30 min), and the effect of electrolytes. Results showed greater PFOS separation in the presence of electrolytes, particularly monovalent cations like Na+, compared to divalent cations such as Ca2+, due to the creation of more stable CGAs with smaller sizes. At a mixing rate of 6000 rpm, 85 % of PFOS was removed in 30 s from a highly contaminated PFOS solution (10 mg/L), with over 95 % separation after 5 mixing cycles. While high-shear mixing was efficient in PFOS separation from highly contaminated solutions it was less efficient for low-level contaminated solutions (less than 1 mg/L). These results suggest that hydrodynamic cavitation induced by high-shear mixing seems promising for enhancing the separation of PFOS from heavily contaminated solutions. This technique could serve as a standalone method or be integrated with other PFAS removal technologies to enhance the overall efficiency of PFAS removal from polluted water sources.

How renal toxins respond to renal function deterioration and oral toxic adsorbent in pH-controlled releasing capsule.

The number of patients with chronic kidney disease (CKD) is increasing. Oral toxin adsorbents may provide some value. Several uremic toxins, including indoxyl sulfate (IS), p-cresol (PCS), acrolein, per- and poly-fluoroalkyl substances (PFAS), and inflammation markers (interleukin 6 [IL-6] and tumor necrosis factor [TNF]-alpha) have been shown to be related to CKD progression. A total of 81 patients taking oral activated charcoal toxin adsorbents (AC-134), which were embedded in capsules that dissolved in the terminal ileum, three times a day for 1 month, were recruited. The renal function, hemoglobulin (Hb), inflammation markers, three PFAS (PFOA, PFOS, and PFNA), and acrolein were quantified. Compared with the baseline, an improved glomerular filtration rate (GFR) and significantly lower acrolein were noted. Furthermore, the CKD stage 4 and 5 group had significantly higher concentrations of IS, PCS, IL-6, and TNF but lower levels of Hb and PFAS compared with the CKD Stage 3 group at baseline and after the intervention. Hb was increased only in the CKD Stage 3 group after the trial (p = .032). Acrolein did not differ between the different CKD stage groups. Patients with improved GFR (responders) (about 77%) and nonresponders had similar baseline GFR. Responders had higher acrolein and PFOA levels throughout the study and a more significant reduction in acrolein, indicating a better digestion function. Responders had higher acrolein and PFOA levels throughout the study and a more significant reduction in acrolein, while PFOA increased in responders. Both the higher PFOA and lower acrolein may be related to improved eGFR (and possibly to improvements in proteinuria, which we did not measure. Proteinuria is associated with PFAS loss in the urine), AC-134 showed the potential to improve the GFR and decrease acrolein, which might better indicate renal function change. Future studies are needed with longer follow-ups.

Uptake and cellular responses of Microcystis aeruginosa to PFOS in various environmental conditions

Although PFOS has been banned as a persistent organic pollutant, it still exists in large quantities within the environment, thus impacting the health of aquatic ecosystems. Previous studies focused solely on high PFOS concentrations, disregarding the connection with environmental factors. To gain a more comprehensive understanding of the PFOS effects on aquatic ecosystems amidst changing environmental conditions, this study investigated the cellular responses of Microcystis aeruginosa to varying PFOS concentrations under heatwave and nutrient stress conditions. The results showed that PFOS concentrations exceeding 5.0 µg/L had obvious effects on multiple physiological responses of M. aeruginosa, resulting in the suppression of algal cell growth and the induction of oxidative damage. However, PFOS concentration at levels below 20.0 µg/L has been found to enhance the growth of algal cells and trigger significant oxidative damage under heatwave conditions. Heatwave conditions could enhance the uptake of PFOS in algal cells, potentially leading to heightened algal growth when PFOS concentration was equal to or less than 5.0 µg/L. Conversely, deficiency or limitation of nitrogen and phosphorus significantly decreased algal abundance and chlorophyll content, inducing severe oxidative stress that could be mitigated by exposure to PFOS. This study holds significance in managing the impact of PFOS on algal growth across diverse environmental conditions.

Associations of dietary intake and longitudinal measures of per- and polyfluoroalkyl substances (PFAS) in predominantly Hispanic young Adults: A multicohort study

BackgroundPer- and polyfluoroalkyl substances (PFAS) are pollutants linked to adverse health effects. Diet is an important source of PFAS exposure, yet it is unknown how diet impacts longitudinal PFAS levels. ObjectiveTo determine if dietary intake and food sources were associated with changes in blood PFAS concentrations among Hispanic young adults at risk of metabolic diseases. MethodsPredominantly Hispanic young adults from the Children’s Health Study who underwent two visits (CHS; n = 123) and young adults from NHANES 2013–2018 who underwent one visit (n = 604) were included. Dietary data at baseline was collected using two 24-hour dietary recalls to measure individual foods and where foods were prepared/consumed (home/restaurant/fast-food). PFAS were measured in blood at both visits in CHS and cross-sectionally in NHANES. In CHS, multiple linear regression assessed associations of baseline diet with longitudinal PFAS; in NHANES, linear regression was used. ResultsIn CHS, all PFAS except PFDA decreased across visits (all p < 0.05). In CHS, A 1-serving higher tea intake was associated with 24.8 %, 16.17 %, and 12.6 % higher PFHxS, PFHpS, and PFNA at follow-up, respectively (all p < 0.05). A 1-serving higher pork intake was associated with 13.4 % higher PFOA at follow-up (p < 0.05). Associations were similar in NHANES, including unsweetened tea, hot dogs, and processed meats. For food sources, in CHS each 200-gram increase in home-prepared food was associated with 0.90 % and 1.6 % lower PFOS at baseline and follow-up, respectively, and in NHANES was associated with 0.9 % lower PFDA (all p < 0.05). ConclusionResults suggest that beverage consumption habits and food preparation are associated with differences in PFAS levels in young adults. This highlights the importance of diet in determining PFAS exposure and the necessity of public monitoring of foods and beverages for PFAS contamination.

HBM4EU chromates study – PFAS exposure in electroplaters and bystanders

The study aims to reveal the exposure to perfluoroalkyl substances (PFAS) in workers in different industry sectors with exposures to hexavalent chromium (Cr(VI)). The PFAS exposure of in total 172 individuals from 4 countries was assessed by the determination of 8 perfluoroalkyl carboxylic acids and 4 perfluoroalkyl sulfonic acids in plasma samples. The participants were 52 chrome plating workers, 43 welders, 3 surface treating workers and 74 workers without any occupational Cr exposure as controls. Significant differences between workers with Cr exposure and controls were found for the perfluoroalkyl sulfonic acids, particularly for perfluorooctane sulfonic acid (PFOS). The median and maximum levels were, respectively, 4.83 and 789 μg/l for chrome plating workers, 4.97 and 1513 μg/l for welders, and 3.65 and 13.9 μg/l for controls. The considerably high PFOS exposure in Cr platers and welders can be explained by the former application of PFOS as mist suppressants in electroplating baths, which resulted in an exposure of the directly involved operators, but also of welders performing maintenance and repair service at these workplaces.

Serum per- and polyfluoroalkyl substance concentrations and longitudinal change in post-infection and post-vaccination SARS-CoV-2 antibodies

Per- and polyfluoroalkyl substances (PFAS) are ubiquitous throughout the United States. Previous studies have shown PFAS exposure to be associated with a reduced immune response. However, the relationship between serum PFAS and antibody levels following SARS-CoV-2 infection or COVID-19 vaccination has not been examined. We examined differences in peak immune response and the longitudinal decline of antibodies following SARS-CoV-2 infection and COVID-19 vaccination by serum PFAS levels in a cohort of essential workers in the United States. We measured serum antibodies using an in-house semi-quantitative enzyme-linked immunosorbent assay (ELISA). Two cohorts contributed blood samples following SARS-CoV-2 infection or COVID-19 vaccination. We used linear mixed regression models, adjusting for age, race/ethnicity, gender, presence of chronic conditions, location, and occupation, to estimate differences in immune response with respect to serum PFAS levels. Our study populations included 153 unvaccinated participants that contributed 316 blood draws over a 14-month period following infection, and 860 participants and 2451 blood draws over a 12-month period following vaccination. Higher perfluorooctane sulfonic acid (PFOS), perfluorohexane sulfonic acid (PFHxS), and perfluorononanoic acid (PFNA) concentrations were associated with a lower peak antibody response after infection (p = 0.009, 0.031, 0.015). Higher PFOS, perfluorooctanoic acid (PFOA), PFHxS, and PFNA concentrations were associated with slower declines in antibodies over time after infection (p = 0.003, 0.014, 0.026, 0.025). PFOA, PFOS, PFHxS, and PFNA serum concentrations prior to vaccination were not associated with differences in peak antibody response after vaccination or with differences in decline of antibodies over time after vaccination. These results suggest that elevated PFAS may impede potential immune response to SARS-CoV-2 infection by blunting peak antibody levels following infection; the same finding was not observed for immune response to vaccination.

Perfluoroalkyl chemicals and mortality: an exploratory analysis using NHANES 1999-2014

Background: Per- and Polyfluoroalkyl Substances (PFAS) are ubiquitous synthetic chemicals that have been widely used in industrial and consumer products, and are detected in the blood of more than 98% of Americans. PFAS have been linked to increased risks of multiple health outcomes such as cardiovascular disease (CVD) and cancer. Aim: To examine the associations of PFAS exposures with all-cause, CVD, and cancer mortality in the general US population using the most up-to-date publicly available data. Methods: The current study included participant-level data for 5,839 adults aged 45 years or older from the National Health and Nutrition Examination Survey (NHANES) 1999-2000 and 2003-2014 that were eligible for linkage to the public-use National Death Index (NDI) Mortality Files. The associations between 5 individual PFAS, including perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorononanoic acid (PFNA), perfluorohexane sulfonic acid (PFHxS), and perfluorodecanoic acid (PFDA) and mortality were examined using survey-weighted Cox-Proportional Hazards model with the age as the time scale. Hazard ratios (HR) were calculated to compare the mortality HR of participants per interquartile range (IQR) increase in log-transformed serum PFAS concentrations. Results: After adjusting for sex, race, education, BMI, hypertension, cholesterol level, and survey cycle, most PFAS were not statistically significantly associated with increased risk of CVD or cancer mortality. While higher PFOS and all PFAS were inversely associated with CVD and all-cause mortality risks, respectively (p &amp;#x3c; 0.05), the observed associations became null when analyses were restricted to participants without chronic kidney disease (CKD). Conclusions: Based on the most available data from NHANES, there was no evidence of increased risks of CVD or cancer mortality due to elevated PFAS concentrations. Further studies are needed to fully understand the inverse associations observed in this study as well as the role of CKD in PFAS related health effects. Keywords: Perfluoroalkyls, mortality, NHANES

Effect of perfluoroalkyl exposure in pregnancy and infancy on intrauterine and childhood growth and anthropometry. Sub study from COPSAC2010 birth cohort.

Perfluoroalkyl substances PFOS and PFOA are persistent and bioaccumulative exogenous chemicals in the human body with a range of suspected negative health effects. It is hypothesised that exposure during prenatal and early postnatal life might have particularly detrimental effects on intrauterine and childhood growth. In a Danish longitudinal mother-child cohort we investigate effect of PFOS and PFOA in pregnancy and infancy on intrauterine and childhood growth and anthropometry. COPSAC2010 is an ongoing population based mother-child cohort of 738 pregnant women and their children followed from 24 week gestation with longitudinal deep clinical phenotyping until age 10 years. In this observational cohort sub study plasma PFOS and PFOA concentrations were semi-quantified by untargeted metabolomics in the mothers at week 24 and 1 week postpartum and in the children at ages 6 and 18 months and calibrated using a targeted pipeline. We examined associations to intrauterine and childhood growth and anthropometry, including interactions with child sex. Untargeted and targeted blood metabolomics profiles were integrated to investigate underlying mechanisms. Pregnancy plasma PFOA concentrations were associated with lower birth size -0.19 [-0.33; -0.05] BMI z-score per 1-ng/mL and increased childhood height (z-scored) at age 6: 0.18 [0.05; 0.31], but there was no association between childs' own infancy plasma PFOA concentration and height. Pregnancy plasma PFOS concentrations were also associated with lower birth BMI (-0.04 [-0.08; -0.01]), but in childhood pregnancy plasma PFOS concentration interacted with child sex on BMI and fat percentage at 6 years with negative associations in girls and positive in boys. The effect of maternal plasma PFOS concentration on lower girl BMI was borderline mediated through increasing child plasma lactosyl-ceramide levels (p-mediation=0.08). Similarly the effect of maternal plasma PFOS concentration on higher boy fat percentage was borderline mediated through increasing child plasma lactosyl-ceramide levels (p-mediation=0.07). Infancy concentrations of plasma PFOS associated with lower height in childhood, -0.06 z-score at age 6 [-0.19; -0.03]. Higher PFOS and PFOA plasma concentrations during pregnancy had detrimental effects on fetal growth. The effects on childhood growth were not similar as PFOA increased child height, opposite of PFOS in multipollutant models suggesting a differing fetal programming effect. Sex specific growth effects were borderline mediated through an altered lactosyl-ceramide metabolism, proposing a possible mechanism of PFOS that has long-lasting health consequences in this observational study. All funding received by COPSAC are listed on www.copsac.com. The Lundbeck Foundation (Grant no R16-A1694); The Novo Nordic Foundation (Grant nos NNF20OC0061029, NNF170C0025014, NNF180C0031764) The Ministry of Health (Grant no 903516); Danish Council for Strategic Research (Grant no 0603-00280B) and The Capital Region Research Foundation have provided core support to the COPSAC research center. Effort from JALS is supported by R01HL123915, R01HL141826, and R01HL155742 from NIH/NHLBI. CEW was supported by the Swedish Heart Lung Foundation (HLF 20180290, HLF 20200693). BC has received funding for this project from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No. 946228). The funding agencies did not have any role in design and conduct of the study; collection, management, and interpretation of the data; or preparation, review, or approval of the manuscript.

Exposure to perfluoroalkyl substances and risk of hepatocellular carcinoma in a multiethnic cohort

Background & AimsExposure to poly- and perfluoroalkyl substances (PFAS), a class of persistent organic pollutants, is ubiquitous. Animal studies suggest that PFAS may increase risk of fatty liver and hepatocellular carcinoma (HCC) via impacts on hepatic lipid, amino acid, and glucose metabolism, but human data is lacking. We examined associations between PFAS exposure, altered metabolic pathways, and risk of non-viral HCC.MethodsIn this nested case-control study, pre-diagnostic plasma PFAS and metabolomics were measured in 50 incident HCC cases and 50 individually matched controls from the Multiethnic Cohort (MEC) study. Cases/controls were matched by age, sex, race, and study area. PFAS exposure and risk of HCC were examined using conditional logistic regression. A metabolome-wide association study and pathway enrichment analysis was performed for PFAS exposure and HCC risk, and key metabolites/metabolic pathways were identified using a meet in the middle approach.ResultsHigh perfluorooctane sulfonic acid (PFOS) levels (90th percentile from NHANES; >55 μg/L) were associated with 4.5-fold increased risk of HCC (odds ratio 4.5, 95% CI 1.2-16.0). Pathway enrichment analysis showed that PFOS exposure was associated with alterations in amino acid and glycan biosynthesis pathways, which were also associated with HCC risk. We identified 4 metabolites linking PFOS exposure with HCC, including glucose, butyric acid (a short-chain fatty acid), α-ketoisovaleric acid (a branched-chain α-keto acid), and 7α-hydroxy-3-oxo-4-cholestenoate (a bile acid), each of which was positively associated with PFOS exposure and risk of HCC.ConclusionThis proof-of-concept analysis shows that exposure to high PFOS levels was associated with increased risk of non-viral HCC, likely via alterations in glucose, amino acid, and bile acid metabolism. Larger studies are needed to confirm these findings.Lay summaryPer- and polyfluoroalkyl substances (PFAS), often referred to as “forever chemicals” because they are difficult to break down and stay in the human body for years, are extremely common and can cause liver damage. In a first of its kind study, we found that exposure to high levels of perfluorooctanesulfonic acid, one of the most common PFAS chemicals, was linked to increased risk of hepatocellular carcinoma in humans. Hepatocellular carcinoma is difficult to treat and is one of the most common forms of liver cancer, and these findings may provide new avenues for helping to prevent this disease.

Effect of abiotic factors and environmental concentrations on the bioaccumulation of persistent organic and inorganic compounds to freshwater fish and mussels

Many aquatic ecosystems are under persistent stress due to influxes of anthropogenic chemical pollutants. High concentrations can harm entire ecosystems and be toxic to humans. However, in case of highly hydrophobic compounds, their low water solubility precludes direct measurement in water, and thus alternative monitoring strategies are needed. In the present study, we investigated the extent to which bioaccumulated concentrations of persistent compounds can be predicted by concentrations in environmental compartments (water and sediment). Due to their high biomagnification potential, Hg and PFOS were included in this analysis as well. At 44 field locations in Flanders (Belgium), we monitored the concentrations of 11 priority compounds and their derivatives, included in the Water Framework Directive, in both sediment and water (where feasible) and biota (European perch, European eel and freshwater mussels). Besides, some sediment (i.e. total organic carbon (TOC) and clay content) and water characteristics were measured (i.e. pH, oxygen level, conductivity, nitrate, nitrite and dissolved organic carbon (DOC)). Measurements of HCB, HCBD, cis-heptachlorepoxide, HBCD and PFOS in sediment and ∑PCB in water showed a lower detection frequency than in fish samples. While PCB profiles were comparable between all matrices, for PBDE clear differences were detected between sediment and fish profiles, with BDE99 contributing the most for sediment (34%) and BDE47 for fish (≥44%), followed by BDE99 for perch (28%) and BDE100 for eel (25%). Water concentrations for PFOS and benzo(a)pyrene were predictive of respective bioaccumulated concentrations. HCB, ∑PCB and ∑PBDE, concentrations in fish were dependent on sediment concentrations and negatively related to organic compound levels (p < 0.05). Furthermore, pH and nitrite were negatively associated with accumulated concentrations in eel for HCB and PFOS, respectively (p < 0.05). Strong relationships between bioaccumulation and sediment and/or water concentrations strengthened the basis for surrogate monitoring methods. Finally, the extrapolation potential of Hg, ∑PBDE, PFOS, HBCD and ∑PCB between both fish species offered new opportunities in extrapolating different European monitoring frameworks.

Effect of lycopene on hepatotoxicity induced by perfluorooctane sulfonic acid in rats

Objective: Intend to observe the liver injury induced by perfluorooctane sulfonic acid (PFOS) in SD rats and the protective effect of lycopene (LP) and its possible mechanism. Methods: 48 SD rats were randomly divided into 8 groups. The solvent control group of LP protection group and LP protection low, middle and high dose PFOS exposure groups were given LP suspension once a day according to their designed dose. The contents of ALT, ASP and AST in serum, the content of MDA in liver tissue and the activity of SOD and GSH-Px in liver tissue were measured after 2 months. Results: The levels of serum ALT, AST and serum ASP enzyme activity in middle and high dose PFOS groups and high dose PFOS groups were significantly higher than those in solvent control group (P < 0 05).The levels of serum ALT, ALP and AST in middle and high dose PFOS groups protected by LP were lower than those in the same dose PFOS group (P < 0 05). The content of MDA in liver tissue of rats treated with LP was significantly lower than that of rats exposed to the same dose of PFOS (P < 0.05). The contents of GSH-Px and SOD in the liver homogenate of the low, middle and high dose PFOS groups decreased compared with the solvent control group. Conclusion: PFOS can induce liver injury in rats, and lycopene can antagonize liver injury induced by PFOS through antioxidant mechanism.

Inflammatory bowel disease and biomarkers of gut inflammation and permeability in a community with high exposure to perfluoroalkyl substances through drinking water

Perfluoroalkyl substances (PFAS) can act as surfactants and have been suggested to be capable of affecting gut mucosa integrity, a possible factor in the pathogenesis of inflammatory bowel disease (IBD). So far, only PFOA has been shown to have a positive association with ulcerative colitis. The present study aimed to investigate the association of PFAS and clinically diagnosed IBD in the Ronneby cohort, a population with high PFAS exposure (especially high PFOS and PFHxS) from Aqueous Film-Forming Foam through drinking water, using registry data. Additionally, to explore associations of PFAS with fecal zonulin and calprotectin, subclinical biomarkers of gut inflammation and permeability, in a sub-set of participants from Ronneby and Karlshamn (a nearby control municipality). The registry study included all people that ever resided in Ronneby municipality at least one year between 1980 and 2013. Yearly exposure to contaminated drinking water was assessed based on residential addresses and waterworks supply data, and the population classified by early, mid and late periods in ascending level of contamination. Diagnosed IBD cases were retrieved from the Swedish National Patient register and cause-of-death register. The Cox proportional hazards model was used to derive the hazard ratios (HRs) for diagnosed IBD. The biomarker study included 189 individuals who provided fecal samples. Serum PFAS were measured using LC-MS/MS. Fecal zonulin and calprotectin were measured using ELISA. Linear regression was used to assess the associations between measured PFAS and biomarker levels. In the registry study, no raised HRs for diagnosed IBD were found for cohort subjects with mid (1995–2004) or late period (2005–2013) exposure compared to never exposure. Early period exposure only (1985–1994) showed raised HRs for Crohn's disease (HR = 1.58, p = 0.048) and other non-specified IBD (HR = 1.38, p = 0.037). In the biomarker study, Karlshamn showed higher fecal calprotectin levels (median = 99.6 mg/kg in Karlshamn vs. 66.8 mg/kg in Ronneby, p = 0.04). A trend of decreased calprotectin with increased serum PFAS indicated higher PFAS was associated with lower degree of gut inflammation (p = 0.002). No association between serum PFAS and fecal zonulin was found. In conclusion, the present study found no consistent evidence to support PFAS exposure as a risk factor for IBD.

Effects of Prenatal Per- and Polyfluroalkyl Substances Exposure on Birth Outcomes and Its Potential Mechanism

TPS 741: Adverse birth outcomes 2, Exhibition Hall, Ground floor, August 28, 2019, 3:00 PM - 4:30 PM Background: The potential effects of prenatal per- and polyfluroalkyl substances (PFASs) exposure on adverse birth outcomes have been observed in animals. Yet the results have been inconclusive in humans and little is known about its potential mechanism. Objectives: We investigated the potential effect of prenatal PFASs exposure on birth outcomes and its potential mechanism in relation to placental 11β-hydroxysteroiddehydrogenase 2 (11β-HSD2). Methods: In total, 369 mother-infant pairs were recruited from a Chinese birth cohort. Birth outcomes including weight, length, head circumference and chest circumference were obtained from medical records. Maternal serum was collected for 10 PFASs measurement including PFOA, PFOS, PFNA, PFUA, PFOSA, and PFHpA etc. The Protein level of 11β-HSD2 was detected in 290 placentas. Multiple linear regression models analyzed the associations between maternal PFASs level and birth outcomes as well as 11β-HSD2. Results: We observed a significant decrease in birth weight with a log-unit increase in PFHpA concentrations regardless of whether exposures were modeled as continuous (β=-185.08, 95%CI: -357.83 to -12.33) or categorical variables (4thquartile: β=-143.16, 95%CI: -267.76 to -18.56). Significantly lower birth weight was also observed for PFOSA in the 3rdquartile (β=-150.95, 95%CI: -275.97 to -25.92) and 4thquartile (β=-139.95, 95%CI: -265.22 to -14.69). Additionally, higher PFOA (β=-0.15, 95%CI: -0.27 to -0.03), PFNA (β=-0.27, 95%CI: -0.48 to -0.07), PFUA (β=-0.27, 95%CI: -0.49 to -0.05) exposure was associated with decreased 11β-HSD2 while 11β-HSD2 was not significantly associated with any of birth outcomes. Conclusions: Our findings suggested the potential impact of prenatal PFASs exposure on birth weight and placental 11β-HSD2. No association for 11β-HSD2 was present for any of birth outcomes, suggesting that decrease in placental 11β-HSD2 levels induced by PFASs exposure may not play an important role in fetal growth. More studies on the potential mechanisms underlying the effect of prenatal PFASs exposure on birth outcomes are warranted.

Maternal serum concentrations of perfluoroalkyl substances during pregnancy and gestational weight gain: The Avon Longitudinal Study of Parents and Children

Perfluoroalkyl substances (PFAS) are chemicals used in the manufacture of consumer products. PFAS may act as endocrine disruptors, influencing metabolic pathways and weight-related outcomes. Previous studies observed an association between perfluorooctane sulfonic acid (PFOS) and higher gestational weight gain among under-/normal weight mothers. We analyzed associations of maternal serum pregnancy concentrations of PFAS with gestational weight gain (GWG) using data from 905 women in a subsample of the Avon Longitudinal Study of Parents and Children. Women were routinely weighed in antenatal check-ups; absolute GWG was determined by subtracting the first weight measurement from the last. Linear regression was used to explore associations of maternal PFAS concentrations with absolute GWG, stratified by prepregnancy body mass index. Associations of maternal PFOS, perfluorooctanoic acid (PFOA), and perfluorohexane sulfonic acid (PFHxS) concentrations with absolute GWG were null; 10% higher PFOS was associated with GWG of −0.03 kg (95% CI: −0.11, 0.06) among under-/normal weight mothers. Ten percent higher perfluorononanoic acid (PFNA) was associated with a higher GWG of 0.09 kg (95% CI: 0.02, 0.16) among under-/normal weight mothers. Overall, findings suggest no association between maternal PFOA, PFOS, and PFHxS concentrations and GWG, and a weak positive association between maternal PFNA and GWG.

Leaching and transport of PFAS from aqueous film-forming foam (AFFF) in the unsaturated soil at a firefighting training facility under cold climatic conditions

The contaminant situation at a Norwegian firefighting training facility (FTF) was investigated 15 years after the use of perfluorooctanesulfonic acid (PFOS) based aqueous film forming foams (AFFF) products had ceased. Detailed mapping of the soil and groundwater at the FTF field site in 2016, revealed high concentrations of per- and polyfluoroalkyl substances (PFAS). PFOS accounted for 96% of the total PFAS concentration in the soil with concentrations ranging from <0.3 μg/kg to 6500 μg/kg. The average concentration of PFOS in the groundwater down-gradient of the site was 22 μg/l (6.5–44.4 μg/l), accounting for 71% of the total PFAS concentration. To get a better understanding of the historic fate of AFFF used at the site, unsaturated column studies were performed with pristine soil with a similar texture and mineralogy as found at the FTF and the same PFOS containing AFFF used at the site. Transport and attenuation processes governing PFAS behavior were studied with focus on cold climate conditions and infiltration during snow melting, the main groundwater recharge process at the FTF. Low and high water infiltration rates of respectively 4.9 and 9.7 mm/day were applied for 14 and 7 weeks, thereby applying the same amount of water, but changing the aqueous saturation of the soil columns. The low infiltration rate represented 2 years of snow melting, while the high infiltration rate can be considered to mimic the extra water added in the areas with intensive firefighting training. In the low infiltration experiment PFOS was not detected in the column leachate over the complete 14 weeks. With high infiltration PFOS was detected after 14 days and concentrations increased from 20 ng/l to 2200 ng/l at the end of the experiment (49 days). Soil was extracted from the columns in 5 cm layers and showed PFOS concentrations in the range < 0.21–1700 μg/kg in the low infiltration column. A clear maximum was observed at a soil depth of 30 cm. No PFOS was detected below 60 cm depth. In the high infiltration column PFOS concentration ranged from 7.4 to 1000 μg/kg, with highest concentrations found at 22–32 cm depth. In this case PFOS was detected down to the deepest sample (~90 cm).Based on the field study, retardation factors for the average vertical transport of PFOS in the unsaturated zone were estimated to be 33–42 and 16–21 for the areas with a low and high AFFF impact, respectively. The estimated retardation factors for the column experiments were much lower at 6.5 and 5.8 for low and high infiltration, respectively. This study showed that PFOS is strongly attenuated in the unsaturated zone and mobility is dependent on infiltration rate. The results also suggest that the attenuation rate increases with time.

Serum Perfluorooctanoic Acid and Birthweight: An Updated Meta-analysis With Bias Analysis.

A recent meta-analysis of 15 studies found a change in birthweight of -12.8 g (95% CI = -23.1, -2.38) per ng/ml PFOA in maternal or cord blood and -27.1 g (-50.6, -3.6) per log ng/ml PFOA. Almost all studies were done in low-exposed populations. There are nine new studies, adding 6,019 births to the previous 6,937 births. We conducted a meta-analysis of 24 studies. To combine all results, we approximated results for untransformed PFOA from nine studies using log-transformed PFOA. We also included another large study, excluded from previous analyses, in a sensitivity analysis. We found a change of birthweight of -10.5 g (-16.7, -4.4) for every ng/ml PFOA in maternal or cord blood. After adding one previously excluded large study, we found little evidence of an association (-1.0 g; 95% CI = -2.4, 0.4). Restricting to studies where blood was sampled from mothers early in the pregnancy or shortly before conception (5,393 births), we found little association of PFOA with birthweight (-3.3 g [-9.6, 3.0]). In studies where blood was sampled late in the pregnancy (7563 pregnancies), lower birthweight was associated with higher PFOA (-17.8 [-25.0, -10.6]). Present human evidence provides only modest support for decreased birthweight with increasing PFOA. Studies with a wide range of exposure, and studies with blood sampled early in pregnancy, showed little or no association of PFOA with birthweight. These are studies in which confounding and reverse causality would be of less concern.

An Updated Meta-Analysis of the Association of Serum PFOA and Birthweight, with an Evaluation of Potential Biases

Background: A recent meta-analysis of 15 studies of PFOA and birthweight found a change of -12.8 grams (95% CI -23.1,-2.38) per ng/ml in maternal or cord blood, and -27.1 grams (95% CI -50.6, -3.6) per log ng/ml PFOA. Almost all studies were done in low-exposed populations. There are now nine new studies, adding 6019 births to the 6937 births in the prior studies.Methods: We conducted a meta-analysis of 24 studies. We approximating untransformed results for study using log transformed PFOA, to allow combining all studies. We also included another large study, excluded from previous analyses, in a sensitivity analysis.Results: We found a change of birthweight of -10.5 grams (-16.7, -4.4) for every ng/ml of maternal or cord blood. After inclusion of one additional large study, we found virtually no evidence of a PFOA effect (-1.0 grams, 95% CI -2.4, 0.4). Restricting to studies in which blood was sampled from mothers early in the pregnancy or shortly before conception (5393 births), we found little association of PFOA with birthweight (-3.3 grams (-9.6, 3.0)). In studies when blood was sampled late in the pregnancy (7563 pregnancies), there was a lower birthweight with higher PFOA (-17.8 (-25.0, -10.6)).Conclusion: Current human evidence provides only modest support for decreased birthweight with increasing PFOA. Studies with a wide range of exposure, and studies with blood sampled early in pregnancy, showed little or no association of PFOA with birthweight. These are studies in which confounding and reverse causality would be of less importance.

Perfluoroalkyl acids in children and their mothers: Association with drinking water and time trends of inner exposures--Results of the Duisburg birth cohort and Bochum cohort studies.

Perfluoroalkyl acids (PFAAs) are widely distributed in the environment and humans are globally exposed with them. Contaminated drinking water can considerably contribute to the inner exposure levels. We report the results of a human biomonitoring study with mother-child pairs living in two German cities, one city with PFAA contaminated drinking water in the sub μg/l-range (Bochum) and the other one without contamination (Duisburg). Furthermore, we studied time trends of exposure levels within the Duisburg cohort study. We measured seven PFAAs (PFOS, PFOA, PFHxS, PFNA, PFBS, PFDeA, PFDoA) in blood samples by high performance liquid chromatography and tandem mass spectrometry. Samples were taken during pregnancy, from umbilical cord blood (2000-2002), 6-7 years (5th follow-up) and 8-10 years after birth (7th follow-up). The consumption of drinking water was recorded by a standardized questionnaire. Statistical analyses were calculated with multiple linear regression models. Children and mothers from Bochum showed higher PFOS and PFOA plasma concentrations than from Duisburg. The median concentrations (μg/l) for children were: PFOS 4.7 vs. 3.3; PFOA 6.0 vs. 3.6μg/l (p≤0.05). Consumption of >0.7 l (children) and >0.9 l (mothers) drinking water/day was associated with 13-18% higher PFOS, PFOA and PFHxS concentrations in children (p≤0.01), and 22% higher PFOA in mothers (p≤0.05). Within the Duisburg cohort, PFAA levels in children peaked in the 5th follow-up study (medians (μg/l): cord plasma: 2.7 (PFOS); 1.9 (PFOA); 5th follow-up: 3.6 (PFOS); 4.6 (PFOA); 7th follow-up: 3.3 (PFOS); 3.6 (PFOA)). PFOS concentrations in mothers declined from pregnancy to the 5th follow-up (medians: 8.7 vs. 4.0μg/l). Residents exposed to PFOS and PFOA through drinking water showed significantly higher PFOS and PFOA concentrations in blood plasma. Although PFAA concentrations in the children slightly decreased from the 5th to the 7th follow-up, we detected increasing exposure trends with increasing age in the 7th follow-up.

Effects of elevated dissolved carbon dioxide and perfluorooctane sulfonic acid, given singly and in combination, on steroidogenic and biotransformation pathways of Atlantic cod

In the aquatic environments, the predicted changes in water temperature, pO2 and pCO2 could result in hypercapnic and hypoxic conditions for aquatic animals. These conditions are thought to affect several basic cellular and physiological mechanisms. Yet, possible adverse effects of elevated CO2 (hypercapnia) on teleost fish, as well as combined effects with emerging and legacy environmental contaminants are poorly investigated. In this study, juvenile Atlantic cod (Gadus morhua) were divided into groups and exposed to three different water bath PFOS exposure regimes (0 (control), 100 and 200μgL−1) for 5 days at 1h/day, followed by three different CO2-levels (normocapnia, moderate (0.3%) and high (0.9%)). The moderate CO2 level is the predicted near future (within year 2300) level, while 0.9% represent severe hypercapnia. Tissue samples were collected at 3, 6 and 9 days after initiated CO2 exposure. Effects on the endocrine and biotransformation systems were examined by analyzing levels of sex steroid hormones (E2, T, 11-KT) and transcript expression of estrogen responsive genes (ERα, Vtg-α, Vtg-β, ZP2 and ZP3). In addition, transcripts for genes encoding xenobiotic metabolizing enzymes (cyp1a and cyp3a) and hypoxia-inducible factor (HIF-1α) were analyzed. Hypercapnia alone produced increased levels of sex steroid hormones (E2, T, 11-KT) with concomitant mRNA level increase of estrogen responsive genes, while PFOS produced weak and time-dependent effects on E2-inducible gene transcription. Combined PFOS and hypercapnia exposure produced increased effects on sex steroid levels as compared to hypercapnia alone, with transcript expression patterns that are indicative of time-dependent interactive effects. Exposure to hypercapnia singly or in combination with PFOS produced modulations of the biotransformation and hypoxic responses that were apparently concentration- and time-dependent. Loading plots of principal component analysis (PCA) produced a significant grouping of individual scores according to the exposure scenarios at day 6 and 9. Overall, the PCA analysis produced a unique clustering of variables that signifies a positive correlation between exposure to high PFOS concentration and mRNA expression of E2 responsive genes. Notably, this pattern was not evident for individuals exposed to PFOS concentrations in combination with elevated CO2 scenarios. To our knowledge, the present study is the first of its kind, to evaluate such effects using combined exposure to a perfluoroalkyl sulfonate and elevated levels of CO2 saturation, representative of future oceanic climate change, in any fish species or lower vertebrate.

Characterization of a Sorbent Derived from Construction and Demolition Waste

Construction and demolition waste (C&amp;D) was employed as a raw material to synthesize sorbent by fusion-hydrothermal process in order to effectively use this type of waste material. The specific surface area and the cation exchange capacity (CEC) values of the sorbent were 308.2 m2 g-1 and 625.6 mmol/100 g-1, respectively. It was found that the sorbent was quite effective for ammonium ion due to the high CEC value. The sorbent possessed high PFOS sorption capacities after load with cationic surfactant (Cetyltrimethyl Ammonium Bromide, CTAB), the sorption capacities of CTAB-modified sorbents enhanced with the increase of CTAB loading amount. This study provides an effective way for the C&amp;D waste utilization.