An automated high-throughput SPE micro-elution method for perfluoroalkyl substances in human serum

Profile of per- and polyfluoroalkyl substances, source appointment, and determinants in Argentinean postpartum women

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) are a group of synthetic chemicals with potential adverse health effects. Information concerning PFAS concentrations in relation to pregnancy is scarce in South America and non-existent in Argentina.

AIM

We aimed to investigate an extended maternal PFAS profile herein serum concentrations in a regional and global view, source appointment, and determinants in Argentinean women.

METHODS

A cross-sectional study with a sampling period from 2011 to 2012 included 689 women from Ushuaia and Salta in Argentina. Serum samples collected two days postpartum were analyzed by ultra-high pressure liquid chromatography coupled to electrospray negative ionisation tandem-quadrupole mass-spectrometry. Principal Component Analysis (PCA) following absolute principal component score-multiple linear regression (APCS-MLR) was used for PFAS source appointments. Determinants of PFAS were explored through a MLR approach. A review of previous studies within the same period was conducted to compare with present levels.

RESULTS

Argentinean PFAS concentrations were the lowest worldwide, with PFOS (0.74 ng/mL) and PFOA (0.11 ng/mL) as the dominant substances. Detection frequencies largely aligned with the compared studies, indicating the worldwide PFAS distribution considering the restrictions. The PCA revealed region-specific loading patterns of two component groups of PFAS, a mixture of replaced and legacy substances in Ushuaia and long-chain in Salta. This might relate to a mix of non-diet and diet exposure in Ushuaia and diet in Salta. Region, age, lactation, parity, household members, migration, bottled water, and freshwater fish were among the determinants of various PFAS.

CONCLUSION

This is the first study to monitor human PFAS exposure in Argentina. Maternal PFAS concentrations were the lowest observed worldwide in the same period. Exposure contributions are suggested to be affected by restrictions and substitutions. Given the limited population-based studies and the emergence of PFAS, it is essential to conduct further monitoring of PFAS in Argentina and South America.

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

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

Early menarche and other endocrine disrupting effects of per- and polyfluoroalkyl substances (PFAS) in adolescents from Northern Norway. The Fit Futures study

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) comprise a large group of chemicals that are ubiquitous in the environment and include recognized persistent organic pollutants. The aim of this cross-sectional study was to investigate possible endocrine disrupting effects of different PFAS in adolescents.

METHODS

Serum concentrations of PFAS, thyroid, parathyroid and steroid hormones were measured in 921 adolescents aged 15-19 years in the Fit Futures study, Northern Norway. The questionnaire included data on self-reported age at menarche and puberty development score (PDS). Multiple linear and logistic regression analyses and principle component analyses (PCA) were used to assess associations of PFAS with hormones concentrations and puberty indices.

RESULTS

In girls, total PFAS (∑PFAS), perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS), perfluorononanoate (PFNA), perfluorodecanoate (PFDA) were positively associated with dehydroepiandrosterone sulfate (DHEAS) and negatively associated with 11-deoxycorticosterone (11-DOC)/DHEAS ratio. In boys, the associations with 11-DOC/DHEAS ratio were positive for ∑PFAS, perfluoroheptanoate (PFHpA), perfluoroheptane sulfonate (PFHpS), PFOA, and PFOS. Perfluoroundecanoate (PFUnDA) was negatively associated with free thyroxine (fT4) and free triiodothyronine (fT3) in boys. PFNA and PFDA were also negatively associated with fT3 in boys. Serum parathyroid hormone concentration (PTH) was negatively associated with ∑PFAS and perfluorohexane sulfonate (PFHxS) in girls, and with PFOS in boys. PFDA and PFUnDA were positively associated with early menarche, while ∑PFAS and PFOA were positively associated with PDS in boys. No associations of PFAS with serum testosterone, follicle-stimulating hormone, or luteinizing hormone were found in either sex. In girls, PFOA was positively associated with free testosterone index (FTI). In boys, PFOA was positively associated with androstendione and 17-OH-progesterone, while PFHpA was positively associated with estradiol.

CONCLUSIONS

Serum concentrations of several PFAS were associated with parathyroid and steroid hormones in both sexes, and with thyroid hormones in boys, as well as with early menarche in girls and higher PDS in boys.

Serum Concentrations of Selected Poly- and Perfluoroalkyl Substances (PFASs) in Pregnant Women and Associations with Birth Outcomes. A Cross-Sectional Study from Southern Malawi

Pervasive exposure to per-and polyfluoroalkyl substances (PFASs) shows associations with adverse pregnancy outcomes. The aim of the present study was to examine the determinants of different serum PFAS concentrations in late pregnancy and their relationship with birth outcomes in southern Malawi. The sample included 605 pregnant women with a mean age of 24.8 years and their offspring from three districts in the southern region of Malawi. Six PFAS were measured in serum from third-trimester women. The serum PFAS concentrations were assessed with head circumference, birth length, birth weight, gestational age and ponderal index. Participants living in urban areas had significantly higher serum levels of PFOA, PFNA and SumPFOS, while SumPFHxS concentrations were higher in women from rural settings. High PFOA, PFNA and SumPFHxS concentrations were generally inversely associated with head circumference. Birth length was negatively associated with PFOA and PFNA while SumPFHxS was negatively associated with birth weight. SumPFOS was inversely associated with gestational age. Urban area of residence was the strongest predictor for high PFAS concentrations in the maternal serum and was generally associated with adverse birth outcomes. The results highlight the need to investigate SumPFHxS further as it follows a pattern that is different to similar compounds and cohorts.

Impaired gross motor development in infants with higher PFAS concentrations

Industrial produced perfluoroalkyl substances (PFAS) are environmentally persistent and found in humans around the globe. PFAS is transferred from mother to child during pregnancy and lactation and PFAS concentrations are high in infants. PFAS exposure in early life has been linked to a range of negative health effects. In the present study we have investigated PFAS concentrations in mothers (pregnancy week 18, 28 and 36 and six weeks, four and six months postpartum, n = 114) and in infants at six months age (n = 94), and studied the effects of PFAS status on infant gross motor development by Alberta Infant Motor Scale (AIMS) at age six months. PFAS concentrations declined in the mothers during pregnancy and postpartum period, and the highest concentrations were seen in infants aged six months. Parity was a strong negative predictor and fish intake a strong positive predictor of maternal PFAS status, while maternal concentrations of PFAS in pregnancy week 18 and months of exclusive breastfeeding determined the PFAS concentrations in infants at six months. Infants who scored below the median on gross motor development had higher PFAS concentrations than infants with a better gross motor development. Ninety percent of the women reported having fish for dinner at least once a week, with fatty fish as the most popular choice (72%). A higher maternal fish intake in pregnancy week 18 was associated with a poorer gross motor development in the infants at six months. Infant gross motor development is a marker of later cognitive outcome and our findings indicate that higher PFAS concentrations in young infants and maternal fatty fish intake may impair neurodevelopment.

Quantitation of linear and branched perfluoroalkane sulfonic acids (PFSAs) in women and infants during pregnancy and lactation

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) are associated with negative health effects, and exposure during fetal life and infancy are of concern. A subgroup of PFAS, linear and branched perfluoroalkane sulfonic acids (PFSA), have significant differences in biochemical reactions, bioaccumulation and potential toxic exposure effects, and data on transfer of PFSA isomers from mother to baby through placenta or in breastmilk are scarce.

OBJECTIVES

The objective was to investigate differences in branched and linear PFSA isomers in never-pregnant, pregnant and postpartum women and infants.

METHODS

Serum concentrations of branched and linear, perfluorohexane sulfonate (PFHxS), perfluoroheptane sulfonate (PFHpS) and perfluorooctane sulfonate (PFOS) were measured in never-pregnant women (n = 158), pregnant and postpartum women (n = 114) and their infants (n = 94) at age six months.

RESULTS

There was a linear relation between maternal PFSA concentrations in pregnancy week 18 and the infant at age six months. The PFSA concentrations in maternal and infant serum varied with a factor up to 20. The maternal branched/ linear PFHxS ratio increased in the latter part of pregnancy (+45%) and remained high postpartum, and was substantially lower in the infants. Branched/linear PFHpS ratio increased during pregnancy and was highest in the infants, while the branched/linear PFOS ratio decreased in the mothers and was high in the infants.

DISCUSSION

The linear relations between PFSA concentrations in infants aged six months and mothers in pregnancy week 18 confirm that pregnancy and lactation are major excretion routes for PFSA, but accumulate in the infant. The observed great variability in PFSA burden among mothers and infants, as well as the reduced maternal transfer of branched PFHxS isoforms and increased transfer of branched PFOS isoforms compared to the respective linear isoforms to the infant, might impact adverse health effects associated with PFSA exposure, but this should be confirmed in future studies.

Development and validation of an LC-MS/MS method for the quantitation of 30 legacy and emerging per- and polyfluoroalkyl substances (PFASs) in human plasma, including HFPO-DA, DONA, and cC6O4

Per- and polyfluoroalkyl substances (PFASs) include persistent organic pollutants whose spread is still ubiquitous. Efforts to substitute substances of high concern with fluorinated alternatives, such as HFPO-DA (GenX), DONA (ADONA), and cC6O4, have been made. The aim of this work was to develop and validate an isotopic dilution liquid chromatography-tandem mass spectrometry (LC–MS/MS) method suitable to quantify 30 PFASs in human plasma. Analytes included legacy PFASs (PFOA, PFOS, and PFHxS), fluorinated alternatives (PFBA, PFBS, 6:2 FTSA, HFPO-DA, DONA, and cC6O4), and newly identified compounds (F-53B and PFECHS). The sample preparation was rapid and consisted of simple protein precipitation and centrifugation. Calibration standards and quality control solutions were prepared with a human pooled plasma containing relatively low background levels of the considered analytes. A complete validation was carried out: the lower limits of quantitation (LLOQs) ranged from 0.009 to 0.245 µg/L; suitable linearity (determination coefficients, R² 0.989–0.999), precision (2.0–19.5%, relative standard deviation), and accuracy (87.9–113.1% of theoretical) were obtained for considered concentration ranges. No significant variations of analyte responses were recorded under investigated storage conditions and during matrix effect tests. The external verification confirmed the accuracy of the method, although limited to 12 analytes. The method was also applied to 38 human plasma samples to confirm its applicability. The developed assay is suitable for large-scale analyses of a wide range of legacy and emerging PFASs in human plasma. To our knowledge, this is the first published method including cC6O4 for human biomonitoring.

Exposure to perfluoroalkyl substances (PFAS) and dyslipidemia, hypertension and obesity in adolescents. The Fit Futures study

BACKGROUND

Prevalence of obesity, hypertension and dyslipidemia has been increasing in children and adolescents worldwide. Exposure to environmental pollutants may contribute to this development. Our aim was to study associations between perfluoroalkyl substances (PFAS) and dyslipidemia, hypertension and obesity in a population-based sample of adolescents.

METHODS

Serum PFAS concentrations were measured in 940 adolescents, mean age 16.4 (SD 1.3) years, from the cross-sectional Fit Futures study by the UHPLC-MS/MS method. The following endpoints were used: hypertension (systolic blood pressure over 130 mmHg and/or diastolic blood pressure over 80 mmHg); obesity (body mass index over 2 z-score, WHO charts for adolescents); dyslipidemia (total cholesterol ≥ 5.17 mmol/L, and/or LDL-cholesterol ≥ 3.36 mmol/l, and/or apolipoprotein B ≥ 1.10 g/L).

RESULTS

Perfluorooctane sulfonate (PFOS), perfluorononanoate (PFNA), perfluorodecanoate (PFDA) and perfluoroundecanoate (PFUnDA) serum concentrations were positively associated with apolipoprotein B, total- and LDL cholesterol. The highest vs. lowest quartiles of total PFAS (∑PFAS), PFNA and PFDA concentrations were positively associated with the risk of dyslipidemia: OR 2.24 (95% CI 1.10-4.54), OR 2.30 (95% CI 1.16-4.57) and 2.36 (95% CI 1.08-5.16), respectively. The highest vs. lowest quartiles of ∑PFAS, perfluorohexane sulfonate (PFHxS), PFOS, perfluorooctanoate (PFOA) concentrations were positively associated with the risk of hypertension: OR 1.91 (95% CI 1.12-3.26), OR 2.06 (95% CI 1.16-3.65), 1.86 (95% CI 1.08-3.19) and 2.08 (95% CI 1.17-3.69) respectively. PFHxS and perfluoroheptane sulfonate (PFHpS) concentrations were positively associated with obesity.

CONCLUSIONS

This cross-sectional study showed a possible link between several PFAS and dyslipidemia, hypertension and obesity in Norwegian adolescents.

Utilization of a NIST SRM: a case study for per- and polyfluoroalkyl substances in NIST SRM 1957 organic contaminants in non-fortified human serum

The National Institute of Standards and Technology (NIST) generates and maintains thousands of Standard Reference Materials (SRMs) to serve commerce worldwide. Many SRMs contain metrologically traceable mass fractions of known organic chemicals and are commercially available to aid the analytical chemistry community. One such material, NIST SRM 1957 Organic Contaminants in Non-Fortified Human Serum, was one of the first materials issued by NIST with measurements for per- and polyfluoroalkyl substances (PFAS) listed on the Certificate of Analysis and was commercially available in 2009. Since the release of SRM 1957, nearly 400 units have been sold to date, and over 50 publications related to PFAS measurements have included this material for multiple analytical purposes, such as a quality control material, for interlaboratory comparison, as an in-house comparison tool, for inter- and intra-day measurement accuracy, as an indicator of isomeric patterns of PFAS, and for other uses. This perspective details the ways SRM 1957 is utilized by the analytical community and how data have been reported in the literature. A discussion on accurately comparing SRM data to generated data is included. Furthermore, we conducted an in-depth investigation around additional applications for NIST SRMs, such as a matrix-matched reference material, and for the identification of targeted compounds during high-resolution mass spectrometry data collection. Ultimately, this manuscript illustratively describes the ways to utilize a NIST SRMs for chemicals of emerging concern.

Per- and Polyfluoroalkyl Substances in Human Serum Samples of Selected Populations from Ghana

The aims of this study were to assess serum concentrations of per- and polyfluoroalkyl substances (PFASs) in selected populations from Ghana, including workers engaged in the repair of electronic equipment (ERWs), and to elucidate PFAS concentrations in relation to blood mercury concentrations (B-Hg) as a biomarker of seafood consumption. In all, 219 participants were recruited into the study, of which 26 were women and 64 were ERWs. Overall, the PFAS concentrations were low. The most abundant components were perfluorooctane sulfonate (PFOS) and perfluorohexane sulfonic acid (PFHxS). Women had generally lower PFAS concentration than men. The ERWs had statistically significantly higher concentrations of perfluorooctanoate (PFOA), which was associated with the concentration of tin in urine. This could indicate exposure during soldering. The concentration of B-Hg was associated with several of the PFASs such as PFOA, PFOS and perfluoroheptane sulfonate (PFHpS). Additionally, the concentrations of perfluorodecanoic acid (PFDA) and perfluoroundecanoate (PFUnDA) were highly associated with the concentrations of B-Hg. It is noteworthy that the linear isomer of PFHxS was strongly associated with B-Hg while the branched isomers of PFHxS were not. In conclusion, the PFAS concentrations observed in the present study are low compared to other populations previously investigated, which also reflects a lower PFAS exposure within the Ghanaian cohorts. ERWs had significantly higher PFOA concentrations than the other participants. Several PFASs were associated with B-Hg, indicating that seafood consumption may be a source of PFAS exposure.

Pre- and post-diagnostic blood profiles of perfluoroalkyl acids in type 2 diabetes mellitus cases and controls

BACKGROUND

Studies exploring the associations between perfluoroalkyl acids (PFAAs) and type 2 diabetes mellitus (T2DM) are rather limited and have reported conflicting results. All studies to date, including prospective ones, have relied on a single blood sample to study this association. Similarly, studies investigating how T2DM status may influence the longitudinal changes in PFAA concentrations have not been previously performed. As PFAA concentrations in humans have changed considerably over the last two decades, and as individuals diagnosed with T2DM usually undergo lifestyle changes that could influence these concentrations, a single blood sample may not necessarily reflect the life-time exposure to PFAA concentrations. Hence, repeated measurements from the same individuals will extend our understanding of how PFAAs are associated with T2DM. The present study, therefore, aimed to explore associations between pre- and post-diagnostic PFAA blood profiles and T2DM and assess factors associated with longitudinal changes in PFAAs in T2DM cases and controls.

METHODS

Questionnaire data and blood samples from women participating in the Norwegian Women and Cancer study were used to conduct a nested case-control study among 46 T2DM cases matched to 85 non-diabetic controls. PFAAs were measured in blood samples collected prior to (2001/02) and after (2005/6) T2DM diagnosis. We investigated the association between PFAAs and incident and prevalent T2DM using conditional logistic regression. We assessed the longitudinal changes in PFAA concentrations within and between matched cases and controls using t-tests and linear regression models.

RESULTS

We observed no significant associations between pre-diagnostic PFAA concentrations and T2DM incidence. Similar results were observed for the post-diagnostic PFAA concentrations and T2DM prevalence. Decrease over time in PFAA concentrations were observed for PFOA and ∑PFOS concentrations, whereas increase over time were observed for PFNA, PFDA and PFUnDA concentrations. Longitudinal trends in PFAA concentrations among T2DM cases were similar to the changes observed in controls.

CONCLUSIONS

The study did not find evidence of association between PFAAs and incident or prevalent T2DM. The longitudinal changes in PFAAs concentrations were not influenced by T2DM status.

A Critical Review on Metal-Organic Frameworks and Their Composites as Advanced Materials for Adsorption and Photocatalytic Degradation of Emerging Organic Pollutants from Wastewater

Water-borne emerging pollutants are among the greatest concern of our modern society. Many of these pollutants are categorized as endocrine disruptors due to their environmental toxicities. They are harmful to humans, aquatic animals, and plants, to the larger extent, destroying the ecosystem. Thus, effective environmental remediations of these pollutants became necessary. Among the various remediation techniques, adsorption and photocatalytic degradation have been single out as the most promising. This review is devoted to the compilations and analysis of the role of metal-organic frameworks (MOFs) and their composites as potential materials for such applications. Emerging organic pollutants, like dyes, herbicides, pesticides, pharmaceutical products, phenols, polycyclic aromatic hydrocarbons, and perfluorinated alkyl substances, have been extensively studied. Important parameters that affect these processes, such as surface area, bandgap, percentage removal, equilibrium time, adsorption capacity, and recyclability, are documented. Finally, we paint the current scenario and challenges that need to be addressed for MOFs and their composites to be exploited for commercial applications.

Perfluoroalkyl substances (PFASs) and mercury in never-pregnant women of fertile age: association with fish consumption and unfavorable lipid profile

Objectives

To examine concentrations of perfluoroalkyl substances (PFASs) and lifestyle factors that may contribute to higher levels of pollutants in never-pregnant women of fertile age.

Design

Observational cross-sectional study.

Setting

Participants were recruited among employees and students at Haukeland University Hospital and the University of Bergen, Norway.

Participants

Healthy, never-pregnant Norwegian women (n=158) of fertile age (18-39 years).

Outcomes

Concentrations of 20 different PFASs, mercury (Hg), lead, cadmium, total, high-density lipoprotein and low-density lipoprotein (LDL) cholesterol, in addition to self-reported data on dietary intake.

Results

Seven PFASs were detected in more than 95% of the women. Women aged 30-39 years had higher concentrations of sum PFAS compared with younger women. Serum PFASs were significantly intercorrelated (rho: 0.34-0.98, p<0.001) and six of them were significantly correlated to whole blood Hg (rho: 0.21-0.74, p<0.01). Fish consumption was the strongest predictor for most serum PFASs and for whole blood Hg. Fish consumption and serum perfluorooctanesulfonic acid (PFOS) concentrations were both positively associated with serum total and LDL cholesterol, established risk factors for cardiovascular disease.

Conclusions

The majority of Norwegian never-pregnant women of fertile age had a mixture of seven different PFASs and Hg detected in their blood. PFAS concentrations were higher in older women and associated with fish intake. As the mean age of women at first birth is increasing, several factors require further consideration including diet, as this may influence the burden of PFAS to the next generation.

Trial registration number

ClinicalTrials.gov ID: NCT03272022, Unique Protocol ID: 2011/2447, Regional Committee for Medical Research Ethics West (2011/2447), 12 January 2012.

Structure-based virtual screening of perfluoroalkyl and polyfluoroalkyl substances (PFASs) as endocrine disruptors of androgen receptor activity using molecular docking and machine learning

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) pose a substantial threat as endocrine disruptors, and thus early identification of those that may interact with steroid hormone receptors, such as the androgen receptor (AR), is critical. In this study we screened 5,206 PFASs from the CompTox database against the different binding sites on the AR using both molecular docking and machine learning techniques. We developed support vector machine models trained on Tox21 data to classify the active and inactive PFASs for AR using different chemical fingerprints as features. The maximum accuracy was 95.01% and Matthew's correlation coefficient (MCC) was 0.76 respectively, based on MACCS fingerprints (MACCSFP). The combination of docking-based screening and machine learning models identified 29 PFASs that have strong potential for activity against the AR and should be considered priority chemicals for biological toxicity testing.

Serum perfluoroalkyl substances (PFAS) and risk of asthma and various allergies in adolescents. The Tromsø study Fit Futures in Northern Norway

BACKGROUND

Exposure to environmental pollutants may contribute to the development of asthma and other allergies. The aim of this study was to investigate possible associations between asthma and other allergies with exposure to perfluoroalkyl substances (PFASs) in adolescents from the Arctic region of Norway.

METHODS

The Tromsø study Fit Futures 1 (TFF1) and 3-year follow-up Fit Futures 2 study (TFF2) included 675 adolescents that completed a questionnaire about health conditions and underwent a clinical examination with blood tests and fractional nitric oxide (FeNO) measurement. Serum concentrations of 18 PFASs were measured by UHPLC-MS/MS method.

RESULTS

Total PFASs (ΣPFAS) serum concentration over 4th quartile was positively associated with asthma in the TFF1 (OR 3.35 (95% CI 1.54-7.29), p = 0.002). Total perfluorooctane sulfonate (ΣPFOS), linear PFOS (linPFOS), linear perfluorohexane sulfonate (linPFHxS) concentrations over 4th quartiles were associated with 2 times higher odds of asthma in the TFF1. The positive associations between ΣPFAS, ΣPFOS, linPFOS and asthma remained statistically significant in the TFF2. ΣPFAS and linPFHxS concentrations over 3rd tertiles were associated with positive marker of eosinophilic airways inflammation FeNO> 25 ppb. Concentrations of ΣPFOS and linPFOS over 3rd quartiles were positively associated with self-reported nickel allergy (OR 2.25 (95% CI 1.17-4.35) p = 0.016 and OR 2.53 (95% CI 1.30-4.90) p = 0.006, respectively). Allergic rhinitis, self-reported pollen allergy, food allergy and atopic eczema were not associated with PFASs concentrations.

CONCLUSIONS

This study of Norwegian adolescents showed a positive association between several PFASs and asthma, as well as between PFOS and nickel allergy.

Perfluoroalkyl substances in adolescents in northern Norway: Lifestyle and dietary predictors. The Tromsø study, Fit Futures 1

Perfluoroalkyl substances (PFASs) are environmentally persistent chemicals widely used in many consumer products due to water and oil proofing and fire-resistant properties. Several PFASs are recognized as environmental pollutants. This study investigated serum concentrations of 18 different PFASs and their associations with diet and lifestyle variables in 940 adolescents (age 15-19 years) who participated in the Fit Futures 1 study in the Troms arctic district of Norway. Serum concentrations of PFASs were analyzed by ultrahigh pressure liquid chromatography coupled to a triple quadrupole mass spectrometer (UHPLC-MS/MS). The most abundant PFASs in this population were perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), perfluorohexane sulfonate (PFHxS), perfluorononanoate (PFNA) and perfluorodecanoate (PFDA) that were found in 99% of the participants. Perfluoroheptane sulfonate (PFHpS) was found in 98% of the participants. Median concentrations were: PFOS 6.20 ng/mL, PFOA 1.92 ng/mL, PFHxS 0.71 ng/mL, PFNA 0.50 ng/mL, PFDA 0.21 ng/mL and PFHpS 0.15 ng/mL. Median of PFASs sum concentration (∑PFAS) was 10.7 ng/mL, the concentration range was 2.6-200.8 ng/mL. Intake of fat fish, fish liver, seagull eggs, reindeer meat and drinks with sugar were the main dietary predictors of several PFASs. Intake of junk food (pizza, hamburger, sausages) was positively associated with PFNA, intake of canned food was positively associated with PFHxS. Intake of fruits and vegetables, milk products, snacks and candy was not associated with PFASs concentrations. Lean fish intake was positively associated with PFUnDA, but not with other PFASs. There was a positive association of ∑PFAS, PFHxS, PFOA, PFNA and PFDA with chewed tobacco use.