Serum Perfluoroalkyl Acids Concentrations Research Articles

Low concentrations of perfluoroalkyl acids (PFAAs) in municipal drinking water associated with serum PFAA concentrations in Swedish adolescents

While highly contaminated drinking water (DW) is a major source of exposure to perfluoroalkyl acids (PFAAs), the contribution of low-level contaminated DW (i.e. < 10 ng/L of individual PFAAs) to PFAA body burdens has rarely been studied. To address this knowledge gap, we evaluated the association between concentrations of perflurooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorohexane sulfonic acid (PFHxS) and perfluorooctane sulfonic acid (PFOS), and their sum (∑4PFAAs) in DW and serum in Swedish adolescents using weighted least squares regression. We paired serum PFAA concentrations in adolescents (age 10–21 years, n = 790) from the dietary survey Riksmaten Adolescents 2016–17 (RMA) with mean PFAA concentrations in water samples collected in 2018 from waterworks (n = 45) supplying DW to the participant residential and school addresses. The median concentrations of individual PFAAs in DW were < 1 ng/L. Median concentrations of PFNA and PFHxS in serum were < 1 ng/g, while those of PFOA and PFOS were 1–2 ng/g. Significant positive associations between PFAA concentrations in DW and serum were found for all four PFAAs and ∑4PFAAs, with estimated serum/DW concentration ratios ranging from 210 (PFOA) to 670 (PFHxS), taking exposure from sources other than DW (background) into consideration. The mean concentrations of PFHxS and ∑4PFAA in DW that would likely cause substantially elevated serum concentrations above background variation were estimated to 0.9 ng/L and 2.4 ng/L, respectively. The European Food Safety Authority has determined a health concern concentration of 6.9 ng ∑4PFAAs/mL serum. This level was to a large degree exceeded by RMA participants with DW ∑4PFAA concentrations above the maximum limits implemented in Denmark (2 ng ∑4PFAAs/L) and Sweden (4 ng ∑4PFAAs/L) than by RMA participants with DW concentrations below the maximum limits. In conclusion, PFAA exposure from low-level contaminated DW must be considered in risk assessment for adolescents.

Quantitative relationships of perfluoroalkyl acids in drinking water associated with serum concentrations above background in adults living near contamination hotspots in Sweden

Contaminated drinking water (DW) is a major source of exposure to per- and polyfluoroalkyl substances (PFAS) at locations around PFAS production/use facilities and military airports. This study aimed to investigate quantitative relationships between concentrations in DW and serum of nine perfluoroalkyl acids (PFAAs) in Swedish adult populations living near contamination hotspots. Short-chained (PFPeA, PFHxA, PFHpA, and PFBS) and long-chained PFAAs (PFOA, PFNA, PFDA, PFHxS and PFOS) were measured in DW and serum. We matched DW and serum concentrations for a total of 398 subjects living or working in areas receiving contaminated DW and in one non-contaminated area. Thereafter, linear regression analysis with and without adjustments for co-variates was conducted. This enabled to derive (i) serum concentrations at background exposure (CB) from sources other than local DW exposure (i.e. food, dust and textiles) at 0 ng/L DW concentration, (ii) population-mean PFAA serum:water ratios (SWR) and (iii) PFAA concentrations in DW causing observable elevated serum PFAA concentrations above background variability. Median concentrations of the sum of nine PFAAs ranged between 2.8 and 1790 ng/L in DW and between 7.6 and 96.9 ng/mL in serum. DW concentration was the strongest predictor, resulting in similar unadjusted and adjusted regression coefficients. Mean CB ranged from <0.1 (PFPeA, PFHpA, PFBS) to 5.1 ng/mL (PFOS). Serum concentrations increased significantly with increasing DW concentrations for all PFAAs except for PFPeA with SWRs ranging from <10 (PFHxA, PFHpA and PFBS) to 111 (PFHxS). Observed elevated serum concentrations above background variability were reached at DW concentrations between 24 (PFOA) and 357 ng/L (PFHxA). The unadjusted linear regression predictions agreed well with serum concentrations previously reported in various populations exposed to low and high DW levels of PFOA, PFHxS and PFOS. The quantitative relationships derived herein should be helpful to translate PFAA concentrations in DW to concentrations in serum at the population level.

Determinants of serum concentrations of perfluoroalkyl acids (PFAAs) in school children and the contribution of low-level PFAA-contaminated drinking water.

Little is known about the demographic/life-style/physiological determinants explaining the variation of serum perfluoroalkyl acid (PFAA) concentrations in children. We identified significant determinants in children and investigated the influence of low-level PFAA-contaminated drinking water (DW) (<10 ng L-1 of single PFAAs) on serum concentrations. Four perfluorosulfonic acids (PFSAs) and 11 perfluorocarboxylic acids (PFCAs) were analyzed in serum from 5th grade children from 11 Swedish schools (N = 200; average age: 12 years) using liquid chromatography-tandem-mass-spectrometry. Data on demography and life-style/physiological factors were obtained by questionnaires. PFAA concentrations in raw and drinking water (DW) were obtained from the water works supplying DW to the schools. In multiple regression analyses school was the determinant contributing most to the variation in PFAA concentrations, with the lowest contribution for PFHpA (10%) and the highest for PFHxS (81%). Girls had lower adjusted mean concentrations of PFHxS, PFOS, PFNA and PFDA than boys, but a higher concentration of PFHxA. Girls reporting onset of menstruation had lower PFHxS and PFOA concentrations than other girls, suggesting menstrual bleeding elimination. Children born by mothers from less industrialized countries had lower mean concentrations of both PFSAs and PFCAs than children with mothers from highly industrialized countries, suggesting differences in early-life exposure. Life-style factors associated with paternal education levels appeared to influence PFAA concentrations differently than maternal education level. Already at an average DW PFHxS concentration of 2 ng L-1, children had a significantly higher adjusted mean serum PFHxS concentration than at an average DW concentration of <1.6 ng PFHxS L-1. Similar results were observed for PFOS and PFOA. The DW variable explained 16% (PFOA) to 78% (PFHxS) of the variation in serum PFAA concentrations, suggesting that low-level-contaminated DW is a significant source of exposure for children in Sweden. Although some of the associations, especially those with menstruation and maternal birth country, should be interpreted with extra caution due to the small size of the study, the results contribute to future work on identifying populations of children at risk of elevated PFAA exposures.

Alternatives of perfluoroalkyl acids and hepatitis B virus surface antibody in adults: Isomers of C8 Health Project in China

Previous epidemiological and experimental studies have shown that legacy perfluoroalkyl acids (PFAAs) are immunotoxic. However, whether the immunosuppressive effects in PFAA alternatives which recently have been widely detected in the environment are unknown. To address this knowledge gap, we investigated the relationship of serum legacy PFAAs and PFAA alternatives with the antibody of hepatitis B virus in adults. We recruited 605 participants from a cross-sectional study, the Isomer of C8 Health Project in China. We measured two representative legacy PFAAs (perfluorooctane sulfonate, PFOS and perfluorooctanoic acid, PFOA), and three PFAA alternatives (two chlorinated polyfluorinated ether sulfonic acids, Cl-PFESAs and perfluorobutanoic acid, PFBA) in serum using ultra-performance liquid chromatograph-tandem mass spectrometry (UPLC-MS/MS). We applied linear and logistic regression models to analyze associations between serum PFAAs and hepatitis B surface antibody (HBsAb) with multivariable adjustments. We found negative associations between serum PFAAs concentrations and HBsAb. Lower serum HBsAb levels (log mIU/mL) were observed for each log-unit increase in linear PFOS (β = −0.31, 95% confidential interval: 0.84, −0.18), 6:2 PFESA (β = −0.81, 95% CI: 1.20, −0.42), 8:2 PFESA (β = −0.29, 95% CI: 0.43, −0.14) and PFBA (β = −0.18, 95% CI: 0.28, −0.08). The association between PFAAs and HBsAb seronegative seemed to be higher for 6:2 PFESA (odds ratio = 3.32, 95% CI: 2.16, 5.10) than its predecessors, linear PFOS (OR = 1.96, 95% CI: 1.37, 2.81) and branched PFOS isomers (OR = 1.64, 95% CI: 1.05, 2.56). We report new evidence that exposure to PFAA alternatives are associated with lower HBsAb in adults. This association seems to be stronger in 6:2 PFESA than PFOS. Our results suggest that more studies are needed to clarify the potential toxicity of PFAA alternatives in human which will facilitate better chemical regulations for PFAAs.

Level and determinants of serum perfluoroalkyl acids (PFAAs) in a population in Klang Valley, Malaysia.

For decades, perfluoroalkyl acids (PFAAs) have been commonly used for industrial and commercial purposes due to their water- and stain-resistant properties. Persistent pollutants that contain PFAAs have been associated with adverse health effects in humans, and many studies have documented dietary intake, indoor air inhalation, and dermal contact as the potential routes for human exposure to PFAAs. The aim of this study was to assess the level of PFAAs in the serum samples of a general population in a specific region in Malaysia. Using 219 serum samples collected from residents of Klang Valley, Malaysia, the levels of nine PFAAs were analyzed using liquid chromatography-tandem mass spectrometry. In addition, questionnaire surveys on the dietary habits and lifestyles of the subjects were conducted. The results showed that PFAA concentrations of up to 32.57 ng/mL were detected in all serum samples. In 82.6% of the participants, at least seven PFAAs were detected in the serum samples, with perfluorooctanesulfonic acid being the predominant PFAA (median = 8.79 ng/mL). In the adjusted regression model, the concentrations of most PFAAs were higher in men than in women and positively correlated with age, although body mass index and smoking were not significantly associated with the serum PFAA concentrations. Taking into consideration the lifestyle variables, significant associations were found between nonstick cookware and perfluorononanoic acid, between dental floss and cosmetics and perfluorodecanoic acid (PFDA), and between leather sofa and perfluoroundecanoic acid (PFUnDA). Besides, consumption of beef was significantly associated with increased levels of serum PFUnDA, whereas consumption of lamb and chicken eggs was negatively associated with the serum levels of PFUnDA and PFDA, respectively.

Liver function biomarkers disorder is associated with exposure to perfluoroalkyl acids in adults: Isomers of C8 Health Project in China

Exposure to chemicals may affect liver enzyme to increase the risk of liver diseases. Perfluoroalkyl acids (PFAAs) are one kind of persistent organic pollutants with hepatotoxic effect in organism. However, data is scarce to characterize the hepatotoxic effects of specific structural PFAA isomers in general population. To address this data gap, we evaluated the association between serum PFAAs concentration and liver function biomarkers in the Isomers of C8 Health Project in China. High performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was used to measure 18 serum PFAAs, except for linear and branched isomers of PFOA/PFOS, nine perfluorinated carboxylic acids (PFCAs) and two perfluorinated sulfonic acids (PFSAs) were also included, in 1605 adult residents of Shenyang, China. Values for nine serum liver function biomarkers were determined by full-automatic blood biochemical analyzer. Linear regression was used to evaluate associations between PFAAs and continuous liver function biomarkers and logistic regression to assess markers dichotomized per clinical reference intervals. Results indicated that serum PFAAs concentrations were associated with liver biomarker levels suggestive of hepatotoxicity, especially for liver cell injury. For example, a 1 ln-unit increase in total- perfluorooctanoic acid (PFOA) exposure was associated with a 7.4% [95% confidence interval (CI): 3.9%, 11.0%] higher alanine aminotransferase (ALT) level in serum. Interestingly, we observed association between branched PFAA isomers and liver biomarkers. For example, one ln-unit increase in branched perfluorooctane sulfonate (PFOS) isomers exposure was associated with a 4.3% increase in ALT level (95% CI: 1.2%, 7.4%) and a 33.0% increased odds of having abnormal ALT (95% CI: 5.0%, 67.0%). Also, we found that PFNA had positive association with ALT [(6.2%, 95% CI: 3.1%, 9.4%) and AST levels (2.5%, 95% CI: 0.5%, 4.5%)]. Logistic regression results showed that PFPeA, PFHxA, PFNA, PFDoDA, PFTrDA and PFTeDA had statistically association with abnormal prealbumin. Conclusively, our results support previous studies showing association between PFAAs exposure and liver function biomarkers. We found new evidence that branched PFAAs isomer exposure is associated with the risk of clinically relevant hepatocellular dysfunction.

Perfluoroalkyl Acids (PFAAs) in Serum from 2-4-Month-Old Infants: Influence of Maternal Serum Concentration, Gestational Age, Breast-Feeding, and Contaminated Drinking Water.

Little is known about factors influencing infant perfluorinated alkyl acid (PFAA) concentrations. Associations between serum PFAA concentrations in 2-4-month-old infants ( n = 101) and determinants were investigated by multiple linear regression and general linear model analysis. In exclusively breast-fed infants, maternal serum PFAA concentrations 3 weeks after delivery explained 13% (perfluoroundecanoic acid, PFUnDA) to 73% (perfluorohexanesulfonate, PFHxS) of infant PFAA concentration variation. Median infant/maternal ratios decreased with increasing PFAA carbon chain length from 2.8 for perfluoroheptanoic acid and perfluorooctanoic acid (PFOA) to 0.53 for PFUnDA and from 1.2 to 0.69 for PFHxS and perfluorooctanesulfonate (PFOS). Infant PFOA, perfluorononanoic acid (PFNA), and PFOS levels increased 0.7-1.2% per day of gestational age. Bottle-fed infants had mean concentrations of PFAAs 2 times lower than and a mean percentage of branched (%br) PFOS isomers 1.3 times higher than those of exclusively breast-fed infants. PFOA, PFNA, and PFHxS levels increased 8-11% per week of exclusive breast-feeding. Infants living in an area receiving PFAA-contaminated drinking water had 3-fold higher mean perfluorobutanesulfonate (PFBS) and PFHxS concentrations and higher mean %br PFHxS. Prenatal PFAA exposure and postnatal PFAA exposure significantly contribute to infant PFAA serum concentrations, depending on PFAA carbon chain length. Moderately PFBS- and PFHxS-contaminated drinking water is an important indirect exposure source.

Associations of serum perfluoroalkyl acid levels with T-helper cell-specific cytokines in children: By gender and asthma status

Perfluoroalkyl acids (PFAAs) are a group of common chemicals that ubiquitously exist in wildlife and humans. Experimental data suggest that they may alter T-lymphocyte functioning in situ by preferentially enhancing the development of T-helper 2 (TH2)- and inhibiting TH1-lymphocyte development and might increase allergic inflammation, but few human studies have been conducted. To evaluate the association between serum PFAAs concentrations and T-lymphocyte-related immunological markers of asthma in children, and further to assess whether gender modified this association, 231 asthmatic children and 225 non-asthmatic control children from Northern Taiwan were recruited into the Genetic and Biomarker study for Childhood Asthma. Serum concentrations of ten PFAAs and levels of TH1 [interferon (IFN)-γ, interleukin (IL)-2] and TH2 (IL-4 and IL-5) cytokines were measured. The results showed that asthmatics had significantly higher serum PFAAs concentrations compared with the healthy controls. When stratified by gender, a greater number of significant associations between PFAAs and asthma outcomes were found in males than in females. Among males, adjusted odds ratios for asthma among those with the highest versus lowest quartile of PFAAs exposure ranged from 2.59 (95% CI: 1.14, 5.87) for the perfluorobutanesulfonate (PFBS) to 4.38 (95% CI: 2.02, 9.50) for perfluorooctanesulfonate (PFOS); and serum PFAAs were associated positively with TH2 cytokines and inversely with TH1 cytokines among male asthmatics. Among females, no significant associations between PFAAs and TH2 cytokines could be detected. In conclusion, increased serum PFAAs levels may promote TH cell dysregulation and alter the availability of key TH1 and TH2 cytokines, ultimately contributing to the development of asthma that may differentially impact males to a greater degree than females. These results have potential relevance in asthma prevention.

Prostate-specific antigen and perfluoroalkyl acids in the C8 health study population.

Purpose:To inform questions raised by inconsistent findings regarding an association between perfluoroalkyl acids (PFAAs) and prostate cancer by assessing the relationship of PFAAs in human serum to prostate-specific antigen (PSA).Materials and Methods:Using 2005 to 2006 survey data from a large survey population, we compared serum PFAA concentrations in adult males with PSA concentrations adjusted for risk factors including age, body mass index, smoking status, and socioeconomic status.Results:Perfluoroalkyl acids are not consistently associated with PSA concentration in general, or with PSA more than 4.0.Discussion:These findings do not provide evidence that PFAA exposure is associated with PSA.

Perfluoroalkyl acids (PFASs) and thyroid disruption in US adults (NHANES 2007-2008)

Background: Perfluoroalkyl acids (PFASs) are known thyroid toxicants in animal studies, but the effect of PFASs on human thyroid hormones is unclear. Aims: To examine PFAS-thyroid hormone associations in a representative, population-based sample of US adults. We hypothesized that people who had undiagnosed autoimmune hypothyroidism, defined as thyroid peroxidase antibody (TPOAb) &gt;9 IU/mL, and low iodine status would be susceptible to PFAS-induced thyroid disruption because of their compromised capacity to regulate thyroid hormone production. Methods: Our sample included 1,525 US adults (?18 years) from the 2007-2008 NHANES study with available serum PFAS and thyroid hormone data, excluding those with a previously-diagnosed thyroid condition and those taking thyroid medications. We evaluated associations between individual serum PFASs (PFHxS, PFNA, PFOA and PFOS), and thyroid hormones (fT4, fT3, fT3/fT4, and TSH) using multivariable linear regression. Models were stratified by TPOAb status (high: ? 9 IU/mL serum, normal &lt; 9 IU/mL), and iodine status (normal: &gt; 100 ?g/L urine, low: ? 100 ?g/L iodine urine), and were adjusted for age, sex, urinary cotinine, race/ethnicity, time of day of serum collection, and, for women, pregnancy and menopause status. Results: Median serum PFAS concentrations, in ng/g, were: 1.9 (PFHxS), 1.5 (PFNA), 4.3 (PFOA) and 13.9 (PFOS). 426 (28%) of participants had low iodine status, 113 (7%) had high TPOAb, and 26 (2%) had both low iodine and high TPOAb. Higher concentrations of all four PFASs were significantly associated (?=0.05) with lower fT4, higher fT3 (PFOS and PFOA only), higher fT3/fT4, and higher TSH in the low iodine / high TPOAb group only. A weak positive association between PFOA and TSH was also found in participants who had low iodine but normal TPOAb. Conclusions: Exposures to PFASs are associated with hypothyroid disruption in adults who have both low iodine and undiagnosed autoimmune hypothyroidism, a population representing about 2.2% (5 million) of US adults.

Serum perfluoroalkyl acids concentrations and memory impairment in a large cross-sectional study

ObjectivesTo examine the cross-sectional association between serum perfluorooctanate (PFOA), perfuorooctane sulfonate (PFOS), perfluorononanoic acid (PFNA) and perfluorohexane sulfonate (PFHxS) concentrations with self-reported memory impairment in adults and the interaction of...

Legacy for Young Men: PFAAs and Human Sperm

Vol. 117, No. 6 EnvironewsOpen AccessLegacy for Young Men: PFAAs and Human Sperm Cynthia Washam Cynthia Washam Search for more papers by this author Published:1 June 2009https://doi.org/10.1289/ehp.117-a256bAboutSectionsPDF ToolsDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InReddit Recent studies suggest that men’s capacity for sperm production may be harmed by toxic exposures in both fetal and later life. Among the potential chemical culprits are the perfluoroalkyl acids (PFAAs), highly persistent degradation products of the polyfluorinated compounds used in products including nonstick cookware and water-resistant coatings for carpeting, clothing, and other textiles. Findings from a new Danish study suggest that exposure to PFAAs may help account for the otherwise unexplained poor semen quality observed in many young men today [EHP117:923–927; Joensen et al.].Studies in the 1990s found that PFAAs diminished testosterone levels and increased estradiol levels in male rats. In human studies, men have appeared to have higher serum PFAA concentrations than have even higher levels compared with those of older men. Young men may therefore be at higher risk for any potential adverse effects posed by these chemicals.Inspired by such observations, the Danish team designed what they believe is the first study of the effects of PFAAs on sperm quality in humans. They focused their investigation on perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) because of these compounds’ prevalence, their long half-lives, and existing evidence that they act as endocrine disruptors. The subjects included 105 young men from the general population who had provided semen samples in 2003 as part of Denmark’s compulsory military draft examination. These men had the highest and lowest testosterone counts of 546 potential subjects considered. Serum levels of PFOA and PFOS were combined to give each man a PFAA score. These scores were used to classify subjects into low-, intermediate-, and high-PFAA groups.Sperm quality varied markedly among all three groups. Compared with the low- and intermediate-PFAA groups, men in the high-PFAA group showed significantly poorer sperm quality in terms of both percentage and total numbers of morphologically normal sperm. Ejaculate from men in the low-PFAA group had a median count of 15.5 million normal sperm compared with 10 million and 6.2 million normal sperm in the intermediate- and high-PFAA groups, respectively. Average sperm concentration and motility also were lower in the high-PFAA group, but not significantly so. PFAAs were not inversely associated with testosterone levels, a finding that was contrary to expectations based on previous animal research.The researchers note that humans and wildlife will be exposed to persistent PFAAs for years to come. They speculate that high exposures to PFAAs may be contributing to low semen quality and subfertility reported in other studies. However, they caution, results from this preliminary study should be corroborated in larger studies.Men with the highest PFAA scores also had the highest percentages and numbers of morphologically abnormal sperm.FiguresReferencesRelatedDetails Vol. 117, No. 6 June 2009Metrics About Article Metrics Publication History Originally published1 June 2009Published in print1 June 2009 Financial disclosuresPDF download License information EHP is an open-access journal published with support from the National Institute of Environmental Health Sciences, National Institutes of Health. All content is public domain unless otherwise noted. Note to readers with disabilities EHP strives to ensure that all journal content is accessible to all readers. However, some figures and Supplemental Material published in EHP articles may not conform to 508 standards due to the complexity of the information being presented. If you need assistance accessing journal content, please contact [email protected]. Our staff will work with you to assess and meet your accessibility needs within 3 working days.