| 1. |
- Hendriks, Hester S., et al.
(författare)
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Effects on neonatal exposure to the flame retardant tetrabrombisphenol-A, aluminum diethylphosphinate or zinc stannate on long-term, potentiation and synaptic protein levels in mice
- 2015
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Ingår i: Archives of Toxicology. - : Springer Nature. - 0340-5761 .- 1432-0738. ; 89:12, s. 2345-2354
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Tidskriftsartikel (refereegranskat)abstract
- Brominated flame retardants such as tetrabromobisphenol-A (TBBPA) may exert (developmental) neurotoxic effects. However, data on (neuro)toxicity of halogen-free flame retardants (HFFRs) are scarce. Recent in vitro studies indicated a high neurotoxic potential for some HFFRs, e.g., zinc stannate (ZS), whereas the neurotoxic potential of other HFFRs, such as aluminum diethylphosphinate (Alpi), appears low. However, the in vivo (neuro)toxicity of these compounds is largely unknown. We therefore investigated effects of neonatal exposure to TBBPA, Alpi or ZS on synaptic plasticity in mouse hippocampus. Male C57bl/6 mice received a single oral dose of 211 µmol/kg bw TBBPA, Alpi or ZS on postnatal day (PND) 10. On PND 17–19, effects on hippocampal synaptic plasticity were investigated using ex vivo extracellular field recordings. Additionally, we measured levels of postsynaptic proteins involved in long-term potentiation (LTP) as well as flame retardant concentrations in brain, muscle and liver tissues. All three flame retardants induced minor, but insignificant, effects on LTP. Additionally, TBBPA induced a minor decrease in post-tetanic potentiation. Despite these minor effects, expression of selected synaptic proteins involved in LTP was not affected. The flame retardants could not be measured in significant amounts in the brains, suggesting low bioavailability and/or rapid elimination/metabolism. We therefore conclude that a single neonatal exposure on PND 10 to TBBPA, Alpi or ZS does affect neurodevelopment and synaptic plasticity only to a small extent in mice. Additional data, in particular on persistence, bioaccumulation and (in vivo) toxicity, following prolonged (developmental) exposure are required for further (human) risk assessment.
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| 2. |
- Alves, Andreia, et al.
(författare)
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Case Study on Screening Emerging Pollutants in Urine and Nails
- 2017
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 51:7, s. 4046-4053
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Tidskriftsartikel (refereegranskat)abstract
- Alternative plasticizers and flame retardants (FRs) have been introduced as replacements for banned or restricted chemicals, but much is still unknown about their metabolism and occurrence in humans. We identified the metabolites formed in vitro for four alternative plasticizers (acetyltributyl citrate (ATBC), bis(2-propylheptyl) phthalate (DPHP), bis(2-ethylhexyl) terephthalate (DEHTP), bis(2ethylhexyl) adipate (DEHA)), and one FR (2,2-bis (chloromethyl)-propane-1,3-diyltetrakis(2-chloroethyl) bisphosphate (V6)). Further, these compounds and their metabolites were investigated by LC/ESI-Orbitrap-MS in urine and finger nails collected from a Norwegian cohort. Primary and secondary ATBC metabolites had detection frequencies (% DF) in finger nails ranging from 46 to 95%. V6 was identified for the first time in finger nails, suggesting that this matrix may also indicate past exposure to FRs as well as alternative plasticizers. Two isomeric forms of DEHTP primary metabolite were highly detected in urine (97% DF) and identified in finger nails, while no DPHP metabolites were detected in vivo. Primary and secondary DEHA metabolites were identified in both matrices, and the relative proportion of the secondary metabolites was higher in urine than in finger nails; the opposite was observed for the primary metabolites. As many of the metabolites present in in vitro extracts were further identified in vivo in urine and finger nail samples, this suggests that in vitro assays can reliably mimic the in vivo processes. Finger nails may be a useful noninvasive matrix for human biomonitoring of specific organic contaminants, but further validation is needed.
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| 3. |
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| 4. |
- Ouyang, Xiyu, et al.
(författare)
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Non-target analysis of household dust and laundry dryer lint using comprehensive two-dimensional liquid chromatography coupled with time-of-flight mass spectrometry
- 2017
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 166, s. 431-437
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Tidskriftsartikel (refereegranskat)abstract
- Household dust and laundry dryer lint are important indoor environmental matrices that may have notable health effects on humans due to chronic exposure. However, due to the sample complexity the studies conducted on these sample matrices until now were almost exclusively on the basis of target analysis. In this study, comprehensive two-dimensional liquid chromatography coupled with time-of flight mass spectrometry (LC x LC-ToF MS) was applied, to enable non-target analysis of household dust as well as laundry dryer lint for the first time. The higher peak capacity and, good orthogonality of LC x LC, together with reduced ion suppression in the MS enabled rapid identification of environmental contaminants in these complex sample matrices. A number of environmental contaminants were tentatively identified based on their accurate masses and isotopic patterns, including plasticizers, flame retardants, pesticides, drug metabolites, etc. The identity of seven compounds: tris(2-butoxyethyl) phosphate, tris(2-chloropropyl) phosphate, n-benzyl butyl phthalate, dibutyl phthalate, tributyl phosphate, triethyl phosphate and N, N-diethyl-meta-toluamide was confirmed using two-dimensional retention alignment and their concentrations in the samples were semi-quantitatively determined.
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| 5. |
- Papadopoulou, Eleni, et al.
(författare)
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Estimating human exposure to perfluoroalkyl acids via solid food and drinks : Implementation and comparison of different dietary assessment methods
- 2017
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Ingår i: Environmental Research. - : Elsevier BV. - 0013-9351 .- 1096-0953. ; 158, s. 269-276
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Tidskriftsartikel (refereegranskat)abstract
- Background: Diet is a major source of human exposure to hazardous environmental chemicals, including many perfluoroalkyl acids (PFAAs). Several assessment methods of dietary exposure to PFAAs have been used previously, but there is a lack of comparisons between methods. Aim: To assess human exposure to PFAAs through diet by different methods and compare the results. Methods: We studied the dietary exposure to PFAAs in 61 Norwegian adults (74% women, average age: 42 years) using three methods: i) by measuring daily PFAA intakes through a 1-day duplicate diet study (separately in solid and liquid foods), ii) by estimating intake after combining food contamination with food consumption data, as assessed by 2-day weighted food diaries and iii) by a Food Frequency Questionnaire (FFQ). We used existing food contamination data mainly from samples purchased in Norway and if not available, data from food purchased in other European countries were used. Duplicate diet samples (n = 122) were analysed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) to quantify 15 PFAAs (11 perfluoroalkyl carboxylates and 4 perfluoroalkyl sulfonates). Differences and correlations between measured and estimated intakes were assessed. Results: The most abundant PFAAs in the duplicate diet samples were PFOA, PFOS and PFHxS and the median total intakes were 5.6 ng/day, 11 ng/day and 0.78 ng/day, respectively. PFOS and PFOA concentrations were higher in solid than liquid samples. PFOS was the main contributor to the contamination in the solid samples (median concentration 14 pg/g food), while it was PFOA in the liquid samples (median concentrations: 0.72 pg/g food). High intakes of fats, oils, and eggs were statistically significantly related to high intakes of PFOS and PFOA from solid foods. High intake of milk and consumption of alcoholic beverages, as well as food in paper container were related to high PFOA intakes from liquid foods. PFOA intakes derived from food diary and FFQ were significantly higher than those derived from duplicate diet, but intakes of PFOS derived from food diary and FFQ were significantly lower than those derived from duplicate diet. We found a positive and statistically significant correlation between the PFOS intakes derived from duplicate diet with those using the food diary (rho = 0.26, p-value = 0.041), but not with the FFQ. Additionally, PFOA intakes derived by duplicate diet were significantly correlated with estimated intakes from liquid food derived from the food diary (rho = 0.34, p = 0.008) and estimated intakes from the FFQ (rho = 0.25, p-value = 0.055). Conclusions: We provide evidence that a food diary or a FFQ-based method can provide comparable intake estimates to PFOS and PFOA intakes derived from a duplicate diet study. These less burdensome methods are valuable and reliable tools to assess dietary exposure to PFASs in human studies.
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| 6. |
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| 7. |
- Schellenberger, Steffen, et al.
(författare)
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Performance and hazard assessment of fluorinated and non-fluorinated state-of-the-art DWR-polymers
- 2016
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Ingår i: SETAC Nantes 2016.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Durable water repellent (DWR) impregnation is applied in textile finishing to impart water and, depending on impregnation chemicals, oil and stain resistance to textiles. Following the phase-out of the mosteffective and predominating DWR-technology based on long-chain perand polyfluoroalkyl substances (PFASs), the textile industry had to find suitable alternatives. This phase-out has resulted in a market where bothfluorinated and non-fluorinated DWRs are available, dividable into three broad groups: short chain PFAS-based, silicone-based and hydrocarbonbased polymers. During our research in the SUPFES (Substitution of prioritised poly- and perfluorinated chemicals to eliminate diffusesources) project, the alternative DWRs were assessed with regards to: (i)their structural properties and connected performance, (ii) loss and degradation processes resulting in diffuse environmental emissions, and (iii) hazard profile for selected emitted substances. We worked withDWR-chemistry and raw material producers to appropriately treat two commercially relevant types of fabrics with the DWR alternative chemistries (fluorinated and non-fluorinated). We compared the performance of the treated fabrics developed in the project by testing the following properties using industrial standardised methods: generalproperties, physical properties, DWR properties and tabilities of properties considering relevant stress- parameters. We demonstrated that non-fluorinated alternatives can have a competitive water repellency incomparison to short-chain PFAS substitutes, but that they lack oil repellence. We further estimated possible loss mechanisms for impurities and/or degradation products from DWR-treated fabrics and conducted a hazard assessment for relevant chemicals based on data available in the literature. Our hazard ranking suggests that hydrocarbonbasedpolymers are the most environmentally benign, followed bysilicone- and fluorocarbon-based polymers. Future work will include risk assessment and life cycle assessments (LCA) to estimate long-term advantages and disadvantages of the different DWR-technologies.
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| 8. |
- van der Veen, Ike, et al.
(författare)
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Development and validation of a method for the quantification of extractable perfluoroalkyl acids (PFAAs) and perfluorooctane sulfonamide (FOSA) in textiles
- 2016
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Ingår i: Talanta. - : Elsevier BV. - 0039-9140 .- 1873-3573. ; 147, s. 8-15
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Tidskriftsartikel (refereegranskat)abstract
- In textiles, like outdoor clothing, per- and polyfluoroalkyl substances (PFASs) are often used for durable water repellency (DWR) of the final products. The analytical performance to determine the concentration of these chemicals available for exposure to humans and to the environment need to be established. Here a method for the extraction and analysis of one class of PFASs, namely perfluoroalkyl acids (PFAAs), in outdoor clothing was developed and validated. The PFAAs which were validated, included perfluoroalkyl carboxylic acids (PFCAs) (C4-C14), and perfluoroalkane sulfonic acids (PFSAs) (C4, C6, C7, C8). In addition, perfluorooctane sulfonamide (FOSA) was included in this study. The method was based on an organic solvent extraction and analysis by high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). No further cleaning was needed. Two commonly used organic solvent compositions were evaluated for the optimal extraction, i.e. methanol and acetone/acetonitrile (80:20, v/v), and the number and duration of the sequential extractions were optimized. Results showed that two sequential extractions with 5 mL methanol and an extraction time of 30 min gave an optimal performance with an extraction efficiency of >90%. The influence of matrix on the quantification of PFAAs was studied. This indicated ion suppression due to different matrix effects or sorption behavior to specific textile samples. Validation of the entire method showed overall recoveries of>80% and relative standard deviations (RSDs) of<9% (n=3) for repeatability and <20% (n=3) for reproducibility. This is the first validation of an analytical method for the analysis of extractable PFCAs, PFSAs and FOSA associated to textiles, which is of high importance due to the regulation of PFAAs in textile.
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| 9. |
- Weiss, Jana M., et al.
(författare)
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Tracing thyroid hormone-disrupting compounds : database compilation and structure-activity evaluation for an effect-directed analysis of sediment
- 2015
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Ingår i: Analytical and Bioanalytical Chemistry. - : Springer Science and Business Media LLC. - 1618-2642 .- 1618-2650. ; 407:19, s. 5625-5634
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Tidskriftsartikel (refereegranskat)abstract
- A variety of anthropogenic compounds has been found to be capable of disrupting the endocrine systems of organisms, in laboratory studies as well as in wildlife. The most widely described endpoint is estrogenicity, but other hormonal disturbances, e.g., thyroid hormone disruption, are gaining more and more attention. Here, we present a review and chemical characterization, using principal component analysis, of organic compounds that have been tested for their capacity to bind competitively to the thyroid hormone transport protein transthyretin (TTR). The database contains 250 individual compounds and technical mixtures, of which 144 compounds are defined as TTR binders. Almost one third of these compounds (n = 52) were even more potent than the natural hormone thyroxine (T-4). The database was used as a tool to assist in the identification of thyroid hormone-disrupting compounds (THDCs) in an effect-directed analysis (EDA) study of a sediment sample. Two compounds could be confirmed to contribute to the detected TTR-binding potency in the sediment sample, i.e., triclosan and nonylphenol technical mixture. They constituted less than 1 % of the TTR-binding potency of the unfractionated extract. The low rate of explained activity may be attributed to the challenges related to identification of unknown contaminants in combination with the limited knowledge about THDCs in general. This study demonstrates the need for databases containing compound-specific toxicological properties. In the framework of EDA, such a database could be used to assist in the identification and confirmation of causative compounds focusing on thyroid hormone disruption.
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