| 1. |
- Lerg, Charlotte A., et al.
(författare)
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Modes of Publication : Introduction
- 2023
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Ingår i: History of Intellectual Culture : International Yearbook of Knowledge and Society - International Yearbook of Knowledge and Society. - 9783111078038 - 9783111077833 ; 2, s. 71-76
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Bokkapitel (refereegranskat)
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| 2. |
- Brits, Martin, et al.
(författare)
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Brominated and organophosphorus flame retardants in South African indoor dust and cat hair
- 2019
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Ingår i: Environmental Pollution. - : Elsevier BV. - 0269-7491 .- 1873-6424. ; 253, s. 120-129
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Tidskriftsartikel (refereegranskat)abstract
- Flame retardants (FRs), such as brominated flame retardants (BFRs) and organophosphorus flame retardants (OPFRs), are diverse groups of compounds used in various products related to the indoor environment. In this study concentrations of eight polybrominated diphenyl ethers (PBDEs), two alternative BFR5 and ten OPFRs were determined in indoor dust (n = 20) and pet cat hair (n = 11) from South Africa. The OPFRs were the major FRs, contributing to more than 97% of the total FR concentration. The median Sigma(10)OPFRs concentrations were 44,800 ng/g in freshly collected dust (F-dust), 19,800 ng/g in the dust collected from vacuum cleaner bags (V-dust), and 865 ng/g in cat hair (C-hair). Tris(1-chloro-2-propyl) phosphate (TCIPP) was the dominant OPFR in the dust samples with median concentrations of 7,010 ng/g in F-dust and 3,590 ng/g in V-dust. Tris(2-butoxyethyl) phosphate (TBOEP) was the dominant OPFR in C-hair, with a median concentration of 387 ng/g. The concentrations of Sigma 8PBDEs were higher in F-dust than in V-dust. BDE209 was the dominant BFR in all three matrices. Bis(2-ethylhexyl)-3,4,5,6-tetrabromo-phthalate (BEH-TEBP) and 2-ethylhexyl-2,3,4,5- tetrabromobenzoate (EH-TBB) showed notable contributions to the BFR profile in cat hair. A worst-case dust exposure estimation was performed for all analytes. The estimated TCIPP daily intake through dust ingestion was up to 1,240 ng/kg bw for toddlers. The results indicate that OPFRs are ubiquitous in South African indoor environment. Indoor dust is a major source of human exposure to environmental contaminants. This can for example occur through hand-to-mouth contact of toddlers, and is an important route of exposure to currently used FRs accumulated on dust particles. The presence of FRs, in particular high concentrations of OPFRs, suggests that children and indoor pet cats may have greater exposure to FRs than adults.
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| 3. |
- Brits, Martin, et al.
(författare)
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Comprehensive two-dimensional gas chromatography coupled to high resolution time-of-flight mass spectrometry for screening of organohalogenated compounds in cat hair
- 2018
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Ingår i: Journal of Chromatography A. - : Elsevier BV. - 0021-9673 .- 1873-3778. ; 1536, s. 151-162
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Tidskriftsartikel (refereegranskat)abstract
- The coupling of comprehensive two-dimensional gas chromatography with high-resolution time of-flight mass spectrometry offers the best separation efficiency combined with accurate mass measurements over a wide mass range. The tremendous power of this screening tool is illustrated by trace qualitative screening analysis of organohalogenated compounds (OHCs) in pet cat hair. Tentative identification was supported by mass spectral database searches and elemental formula prediction from the experimentally determined accurate mass data. This screening approach resulted in the first tentative identification of pentabromoethylbenzene, decabromodiphenyl ethane, hexabromocyclododecane, trisbromoneopentyl alcohol, tris(2-chloroethyl) phosphate and tris(2-chloroisopropyl)phosphate in the South African indoor environment. A total of seventy-two OHCs were identified in the samples and include known flame retardants, such as polybrominated diphenyl ethers, and legacy contaminants such as polychlorinated biphenyls and organochlorine, organophosphorous and pyrethroid pesticides. The results obtained from cat hair indicate that these pets are exposed to complex mixtures of OHCs and the detection of these compounds suggests that non-invasive cat hair samples can be used to model indoor exposure with reference to external deposition of OHCs present in the air and dust surrounding people. Toddlers share the same environment as pet cats and therefore also the same health risks.
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| 4. |
- Brits, Martin, et al.
(författare)
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Critical review of the analysis of brominated flame retardants and their environmental levels in Africa
- 2016
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 164, s. 174-189
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Forskningsöversikt (refereegranskat)abstract
- World-wide, the prevalence of brominated flame retardants (BFRs) is well documented for routine analysis of environmental and biological matrices. There is, however, limited information on these compounds in the African environment and insufficient information on the analytical approaches used to obtain data. This paper presents a review on BFR levels in the African environment and the various analytical methodologies specifically applied in Africa for polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls and alternative-BFRs. The analyses include liquid sample preparation using liquid-liquid and solid phase extraction and solid sample preparation involving Soxhlet extraction, with ultrasound-assisted extraction increasingly being applied. Instrumental detection techniques were limited to gas chromatography coupled with electron capture detector and electron impact ionisation with single quadrupole mass spectrometers. Information on congener profile prevalence in indoor dust, soil, aquatic environment (water, sediment, and aquatic organisms), eggs, wastewater treatment plant compartments, landfills (leachate and sediment) and breast milk are presented. Although PBDEs were inconsistently detected, contamination was reported for all investigated matrices in the African environment. The manifestation in remote regions indicates the ubiquitous prevalence and long-range transport of these compounds. Levels in sediment, and breast milk from some African countries were higher than reported for Asia and Europe. Due to limited data or non-detection of alternative-BFRs, it is unclear whether banned formulations were replaced in Africa. Most of the data reported for BFR levels in Africa were obtained in non-African laboratories or in South Africa and formed the basis for our discussion of reported contamination levels and related methodologies.
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| 5. |
- Brits, Martin, et al.
(författare)
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Short-, medium-, and long-chain chlorinated paraffins in South African indoor dust and cat hair
- 2020
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 238
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Tidskriftsartikel (refereegranskat)abstract
- Polychlorinated n-alkanes or chlorinated paraffins (CPs) contain a magnitude of structural isomers and are categorized as short-chain (SCCPs), medium-chain (MCCPs), and long-chain (LCCPs) CPs, according to the carbon chain lengths. In this study the Sigma SCCPs, Sigma MCCPs, and Sigma LCCP concentrations are reported for South African indoor dust and pet cat hair. The median concentrations of the Sigma CPs (C-9-C-37) ranged from 33 to 663 mu g/g for freshly collected dust (FD), 36-488 mu g/g for dust collected from household vacuum cleaner bags (VD), and 1.2-15 mu g/g for cat hair (CH) samples. MCCPs were the dominant CP group, followed by SCCPs and LCCPs. The Sigma MCCP concentration ranged from 13 to 498 mu g/g in dust and 0.6-6.5 mu g/g in cat hair. SCCPs with shorter carbon chains and lower chlorine substitution were observed in cat hair. LCCPs with carbon chains > C(20)were detected in dust and hair samples, possibly indicating the use of wax grade LCCP formulations. Non-traditional Kendrick mass defect plots were used to obtain information on the magnitude of CPs and provide evidence of possible interfering compounds. This is the first report on the occurrence of SCCPs, MCCPs, and LCCPs in the South African indoor environment.
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| 6. |
- Carlsson, Gunnar, et al.
(författare)
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Thyroid disruption properties of three indoor dust chemicals tested in Silurana tropicalis tadpoles
- 2019
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Ingår i: Journal of Applied Toxicology. - : Wiley. - 0260-437X .- 1099-1263. ; 39:9, s. 1248-1256
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Tidskriftsartikel (refereegranskat)abstract
- Indoor dust contains a multitude of industrial chemicals, and ingestion of dust is considered an important exposure route to organic contaminants. Some of these contaminants have been shown to interfere with the thyroid system, which may result in significant consequences on public health. The amphibian metamorphosis is a thyroid hormone-dependent process, which can be used as an in vivo model for studies on thyroid hormone-disrupting potency. Three contaminants of indoor dust were tested on metamorphosing Silurana (Xenopus) tropicalis tadpoles. The tested chemicals were Tris (1,3-dichloroisopropyl) phosphate (TDCiPP), tetrabromobisphenol-A (TBBPA) and propylparaben (PrP). Measurements reflecting general growth, development progress and thyroid epithelial cell height were performed on the exposed tadpoles as well as chemical analyses of the exposure water. It was shown that TDCiPP acts as a thyroid hormone-disrupting chemical in metamorphosing tadpoles by causing increased epithelial cell height in thyroid glands after exposure to a nominal concentration of 0.010 mg/L and in higher concentrations. TBBPA caused reductions in general growth of tadpoles at the nominal concentration 0.125 mg/L, and PrP caused acute toxicity at the nominal concentration 12.5 mg/L. However, no evident indications of specific thyroid-disrupting effects caused by TBBPA or PrP were observed.
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| 7. |
- Dracheva, Elena, et al.
(författare)
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In Silico Identification of Potential Thyroid Hormone System Disruptors among Chemicals in Human Serum and Chemicals with a High Exposure Index
- 2022
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 56:12, s. 8363-8372
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Tidskriftsartikel (refereegranskat)abstract
- Data on toxic effects are at large missing the prevailing understanding of the risks of industrial chemicals. Thyroid hormone (TH) system disruption includes interferences of the life cycle of the thyroid hormones and may occur in various organs. In the current study, high-throughput screening data available for 14 putative molecular initiating events of adverse outcome pathways, related to disruption of the TH system, were used to develop 19 in silico models for identification of potential thyroid hormone system-disrupting chemicals. The conformal prediction framework with the underlying Random Forest was used as a wrapper for the models allowing for setting the desired confidence level and controlling the error rate of predictions. The trained models were then applied to two different databases: (i) an in-house database comprising xenobiotics identified in human blood and ii) currently used chemicals registered in the Swedish Product Register, which have been predicted to have a high exposure index to consumers. The application of these models showed that among currently used chemicals, fewer were overall predicted as active compared to chemicals identified in human blood. Chemicals of specific concern for TH disruption were identified from both databases based on their predicted activity.
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| 8. |
- Engelhardt, A. Josefin, 1992-, et al.
(författare)
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Anthropogenic Organic Contaminants Analysed in Human Blood and Combined Risk
- 2023
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Ingår i: Exposure and Health. - : Springer Science and Business Media LLC. - 2451-9766 .- 2451-9685. ; 15:3, s. 551-565
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Forskningsöversikt (refereegranskat)abstract
- The number of chemicals in the anthroposphere is increasing and some of them end up in humans. A literature search was made to assess which anthropogenic organic contaminants (OCs) that have been analysed in blood from the general population. The reviewed articles were used to create a database of studies [human blood database (HBDB), containing 559 OCs] reporting blood analyses made worldwide. All studies analysing blood from the Swedish population were compiled into a second database [Swedish exposure database (SEDB), containing 166 OCs] listing blood concentrations of OCs. Data from the SEDB showed decreasing levels of regulated chemicals in blood over time, indicating that regulation had made an impact. The Hazard Index (HI) approach was used as a qualitative mixture risk assessment of the OCs with established human biomonitoring guidance values (HBM-GVs) and blood levels in the SEDB. Nine HBM-GVs were found and the HI of the corresponding OCs/groups of OCs showed that a risk of adverse effects in the general population could not be excluded, which is a cause for concern considering that only a fraction of the analysed OCs in the SEDB were included. This study presents the OCs identified in human blood and concentration time trends. The study highlights the lack of HBM-GVs needed for mixture risk assessments to assess the combined risk of chemical exposure to the general population.
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| 9. |
- Gustafsson, Åsa, 1975-, et al.
(författare)
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Estimated daily intake of per- and polyfluoroalkyl substances related to different particle size fractions of house dust
- 2022
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Ingår i: Chemosphere. - : Pergamon Press. - 0045-6535 .- 1879-1298. ; 303:Pt 2
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Tidskriftsartikel (refereegranskat)abstract
- Indoor environmental pollutants are a threat to human health. In the current study, we analysed 25 per- and polyfluoroalkyl substances (PFASs) in seven different size fraction of house dust including the two relevant for exposure via ingestion and inhalation. The highest PFAS concentration is found in the inhalable particulate fraction which is explained by the increased surface area as the particulate's sizes decrease. The estimated daily intake (EDI) of the individual PFAS and exposure pathways were calculated for children and adults. In addition, the total EDI for PFOA and its precursors was estimated. The polyfluoroalkyl phosphoric acid diesters (diPAP), followed by PFOA and PFHxA fluortelomer, showed the highest concentrations of PFAS analysed. The cumulative EDI of PFAS for children was 3.0 ng/kg bw per day, a worst-case scenario, which is 17 times higher than the calculated EDI for adults. For children, ingestion of dust was found to result in 800 times higher PFOA exposure than via inhalation. The contribution from PFOA precursors corresponded to only 1% of the EDI from dust indicating PFOA as the main source of exposure. The EDI's of PFOA and PFOS from dust were lower than the calculated EDI's from food ingestion reported by the Swedish Food Agency. Our data indicate that the EDI for the sum of four PFASs: PFOA, PFNA, PFHxS and PFOS from dust intake alone is close to the established tolerable weakly intake of 4.4 ng/kg bw in children, set by European Food Safety Authority (EFSA) in 2020. The combined EDI levels PFOA and PFOS from both dust and food exceeded the EFSA TWI for both children and adults. This study demonstrates that dust is a relevant exposure pathway for PFAS intake and that analysis of relevant particle size fractions is important for evaluation of dust as an exposure pathway.
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| 10. |
- Hamers, Timo, et al.
(författare)
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Transthyretin-Binding Activity of Complex Mixtures Representing the Composition of Thyroid-Hormone Disrupting Contaminants in House Dust and Human Serum
- 2020
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Ingår i: Journal of Environmental Health Perspectives. - 0091-6765 .- 1552-9924. ; 128:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: House dust contains many organic contaminants that can compete with the thyroid hormone (TH) thyroxine (T-4) for binding to transthyretin (TTR). How these contaminants work together at levels found in humans and how displacement from TTR in vitro relates to in vivo T-4-TTR binding is unknown. OBJECTIVES: Our aims were to determine the TTR-binding potency for contaminant mixtures as found in house dust, maternal serum, and infant serum; to study whether the TTR-binding potency of the mixtures follows the principle of concentration addition; and to extrapolate the in vitro TTR-binding potency to in vivo inhibition levels of T-4-TTR binding in maternal and infant serum. METHODS: Twenty-live contaminants were tested for their in vitro capacity to compete for TTR-binding with a fluorescent FITC-T-4 probe. Three mixtures were reconstituted proportionally to median concentrations for these chemicals in house dust, maternal serum, or infant serum from Nordic countries. Measured concentration-response curves were compared with concentration-response curves predicted by concentration addition. For each reconstituted serum mixture, its inhibitor-TTR dissociation constant (K-i) was used to estimate inhibition levels of T-4-TTR binding in human blood. RESULTS: The TTR-binding potency of the mixtures was well predicted by concentration addition. The similar to 20% inhibition in FITC-T-4 binding observed for the mixtures reflecting median concentrations in maternal and infant serum was extrapolated to 1.3% inhibition of T-4-TTR binding in maternal and 1.5% in infant blood. For nontested mixtures reflecting high-end serum concentrations, these estimates were 6.2% and 4.9%, respectively. DISCUSSION: The relatively low estimated inhibition levels at median exposure levels may explain why no relationship between exposure to TTR-binding compounds and circulating T-4 levels in humans has been reported, so far. We hypothesize, however, that 1.3% inhibition of T-4-TTR binding may ultimately be decisive for reaching a status of maternal hypothyroidism or hypothyroxinemia associated with impaired neurodevelopment in children.
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| 11. |
- Jones, Bernt, et al.
(författare)
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Are persistent organic pollutants important in the etiology of feline hyperthyroidism? A review
- 2019
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Ingår i: Acta Veterinaria Scandinavica. - : Springer Science and Business Media LLC. - 0044-605X .- 1751-0147. ; 61:1
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Forskningsöversikt (refereegranskat)abstract
- Feline hyperthyroidism is a rather new disease, first reported from the North American east coast in 1979. The prevalence is increasing, especially in older cats, and hyperthyroidism is now reported worldwide as the most common feline endocrinopathy. Several studies have been performed trying to identify important etiological factors such as exposure to persistent organic pollutants, and especially brominated flame retardants, have been suggested to be of importance for the development of the disease. Recent studies have shown higher concentrations of these contaminants in serum of hyperthyroid cats in comparison to cats with normal thyroid status. However, other still unknown factors are most probably of importance for the development of this disease.
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| 12. |
- Khabazbashi, Sara, et al.
(författare)
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Estimation of the concentrations of hydroxylated polychlorinated biphenyls in human serum using ionization efficiency prediction for electrospray
- 2022
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Ingår i: Analytical and Bioanalytical Chemistry. - : Springer Science and Business Media LLC. - 1618-2642 .- 1618-2650. ; 414:25, s. 7451-7460
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Tidskriftsartikel (refereegranskat)abstract
- Hydroxylated PCBs are an important class of metabolites of the widely distributed environmental contaminants polychlorinated biphenyls (PCBs). However, the absence of authentic standards is often a limitation when subject to detection, identification, and quantification. Recently, new strategies to quantify compounds detected with non-targeted LC/ESI/HRMS based on predicted ionization efficiency values have emerged. Here, we evaluate the impact of chemical space coverage and sample matrix on the accuracy of ionization efficiency-based quantification. We show that extending the chemical space of interest is crucial in improving the performance of quantification. Therefore, we extend the ionization efficiency-based quantification approach to hydroxylated PCBs in serum samples with a retraining approach that involves 14 OH-PCBs and validate it with an additional four OH-PCBs. The predicted and measured ionization efficiency values of the OH-PCBs agreed within the mean error of 2.1 × and enabled quantification with the mean error of 4.4 × or better. We observed that the error mostly arose from the ionization efficiency predictions and the impact of matrix effects was of less importance, varying from 37 to 165%. The results show that there is potential for predictive machine learning models for quantification even in very complex matrices such as serum. Further, retraining the already developed models provides a timely and cost-effective solution for extending the chemical space of the application area.
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| 13. |
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| 14. |
- Li, Li, et al.
(författare)
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Characterization of residential household dust from Shanghai by particle size and analysis of organophosphorus flame retardants and metals
- 2019
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Ingår i: Environmental Sciences Europe. - : Springer. - 2190-4707 .- 2190-4715. ; 31:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Physical and biological properties of dust particles might affect the availability and distribution of chemicals associated to indoor dust; however it has not been adequately examined. In this study, household dust from Shanghai was fractionated into five particle sizes and size distribution, morphology, surface area, organic matter, microorganisms, elemental composition, metals and organophosphorus flame retardants (OPFRs) compositions were characterized. Also, household dust samples from Stockholm that has previously been characterized were included in the analysis of OPFRs for comparison.Results: The respirable fraction had a yield of 3.3% in mass percentage, with a particle size of 2.22 +/- 2.04 mu m. As expected, both metals and OPFRs concentrations increased with decreased particle size. Al and Fe dominated (66-87%) followed by the concentrations of Zn (5-14%) and Ga (1.8-5%) of the sum of 16 metals in the dust. The concentrations of OPFRs in Shanghai dust ranged from 5.34 to 13.7 mu g/g (median: 7.21 mu g/g), compared to household dust from Stockholm that ranged from 16.0 to 28.3 mu g/g (median: 26.6 mu g/g). Tris(2-chloroisopropyl) phosphate (TCIPP) and tris(2-chloroethyl) phosphate (TCEP) dominated in Shanghai dust samples while tris(2-butoxyethyl) phosphate (TBOEP) dominated in dust from Stockholm homes.Conclusion: The results showed that mass percentage for each particle size fraction was not evenly distributed. Furthermore, the particle-bound microorganisms and OPFRs increased with decreased particle size, whereas metals had the highest concentrations at specific dust sizes. Therefore, it is essential to select the proper particle size in order to assess any specific human exposure study to indoor pollutants.
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| 15. |
- Meijer, Lisethe, et al.
(författare)
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Serum concentrations of neutral and phenolic organohalogens in pregnant women and some of their infants in The Netherlands.
- 2008
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Ingår i: Environ Sci Technol. - 0013-936X. ; 42:9, s. 3428-33
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Tidskriftsartikel (refereegranskat)abstract
- As part of a large European Union (EU)-funded comparative toxicology and human epidemiology study, EU-Compare, a selection of organohalogen compounds (OHCs) was analyzed in maternal serum, collected at the 35th week of pregnancy, and in cord serum of a number of their infants to determine maternal concentrations and to investigate the extent of transplacental transfer of these compounds. Eight neutral OHCs were analyzed: one polychlorinated biphenyl (PCB: CB-153),4,4'-DDE, five polybrominated diphenyl ethers (PBDEs: BDE-47, BDE-99, BDE-100, BDE-153, and BDE-154), and hexabromocyclododecane (HBCDD). Five phenolic OHCs were analyzed: three hydroxylated PCBs (40H-CB-107, 40H-CB-146, and 40H-CB-187), one hydroxylated PBDE (60H-BDE-47), and pentachlorophenol (PCP). All OHCs, except 60H-BDE-47, were present in maternal and cord serum. The historically identified OHCs showed the highest concentration: 4,4'-DDE (median value 89 ng/g lipid in maternal serum and 68 ng/g lipid in cord serum) and PCP (median value 970 pg/g serum in maternal serum and 1500 pg/g serum in cord serum). HBCDD and the PBDEs were present at much lower concentrations. We conclude that OHCs are present in the serum of pregnant women, and all compounds tested are transferred over the placenta. Because transfer is occurring at a critical stage of infant development, investigation of the health impact is urgent.
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| 16. |
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| 17. |
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| 18. |
- Norrgran Engdahl, Jessica, et al.
(författare)
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Cats' Internal Exposure to Selected Brominated Flame Retardants and Organochlorines Correlated to House Dust and Cat Food
- 2017
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 51:5, s. 3012-3020
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Tidskriftsartikel (refereegranskat)abstract
- Pet cats may be used as a biomarker for assessing exposures to organohalogen compounds (OHCs) adsorbed to household dust in home environments. This study explores two exposure routes of OHCs, ingestion of OHCs (i) via house dust and (ii) via cat food. House dust from 17 Swedish homes and serum from the participating families' pet cats were collected, and cat food was purchased matching the diet reported. Paired samples of cat serum, house dust, and cat food were analyzed for brominated flame retardants/natural products (polybrominated diphenyl ethers (PBDEs), decabromobiphenyl (BB-209), decabromodiphenyl ethane (DBDPE), 2,4,6-tribromophenol (2,4,6-TBP), OH-PBDEs) and organochlorines (polychlorinated biphenyls (PCBs), 1,1-bis(4,4'-dichlorodipheny1)-2,2,2-trichloroethane (4,4'-DDT), 1,1-bis(4,4'-dichlorodiphenyl)-2,2-dichloroethene (4,4'-DDE), hexachlorobenzene (HCB), pentachlorophenol (PCP)). Significant correlations were found between serum and dust samples from the living rooms for BDE-47 (p < 0.035), BDE-99 (p < 0.035), and BDE-153 (p < 0.039), from the adult's bedroom for BDE-99 < 0.019) and from all rooms for BDE-99 (p < 0.020) and BB-209 (p < 0.048). This is the first time a correlation between cat serum levels and household dust has been established, a finding that supports the hypothesis that dust is a significant exposure route for cats. Serum levels were also significantly correlated with concentrations found in cat food for 6-OH-BDE47 (p < 0.002), 2,4,6-TBP (p < 0.035), and BB-209 (p < 0.007). DBDPE was found in high concentrations in all dust (median 154 pmol/g) and food samples (median 0.7 pmol/ig lw) but was below detection in serum samples, suggesting low or no bioavailability for DBDPE in cats.
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| 19. |
- 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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| 20. |
- Palm, Emma, et al.
(författare)
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Gas Phase Reactivity of Isomeric Hydroxylated Polychlorinated Biphenyls
- 2024
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Ingår i: Journal of the American Society for Mass Spectrometry. - 1044-0305 .- 1879-1123.
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Tidskriftsartikel (refereegranskat)abstract
- Identification of stereo- and positional isomers detected with high-resolution mass spectrometry (HRMS) is often challenging due to near-identical fragmentation spectra (MS2), similar retention times, and collision cross-section values (CCS). Here we address this challenge on the example of hydroxylated polychlorinated biphenyls (OH-PCBs) with the aim to (1) distinguish between isomers of OH-PCBs using two-dimensional ion mobility spectrometry (2D-IMS) and (2) investigate the structure of the fragments of OH-PCBs and their fragmentation mechanisms by ion mobility spectrometry coupled to high-resolution mass spectrometry (IMS-HRMS). The MS2 spectra as well as CCS values of the deprotonated molecule and fragment ions were measured for 18 OH-PCBs using flow injections coupled to a cyclic IMS-HRMS. The MS2 spectra as well as the CCS values of the parent and fragment ions were similar between parent compound isomers; however, ion mobility separation of the fragment ions is hinting at the formation of isomeric fragments. Different parent compound isomers also yielded different numbers of isomeric fragment mobilogram peaks giving new insights into the fragmentation of these compounds and indicating new possibilities for identification. For spectral interpretation, Gibbs free energies and CCS values for the fragment ions of 4 '-OH-CB35, 4 '-OH-CB79, 2-OH-CB77 and 4-OH-CB107 were calculated and enabled assignment of structures to the isomeric mobilogram peaks of [M-H-HCl](-) fragments. Finally, further fragmentation of the isomeric fragments revealed different fragmentation pathways depending on the isomeric fragment ions.
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| 21. |
- Pohl, Johannes, et al.
(författare)
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Carbamazepine Ozonation Byproducts : Toxicity in Zebrafish (Danio rerio) Embryos and Chemical Stability
- 2020
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 54:5, s. 2913-2921
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Tidskriftsartikel (refereegranskat)abstract
- Carbamazepine (CBZ) is an anticonvulsant medication with highly persistent properties in the aquatic environment, where it has the potential to affect nontarget biota. Because CBZ and many other pharmaceuticals are not readily removed in conventional sewage treatment plants (STP), additional STP effluent treatment technologies are being evaluated and implemented. Whole effluent ozonation is a prospective method to remove pharmaceuticals such as CBZ, yet knowledge on the toxicity of CBZ ozonation byproducts (OBPs) is lacking. This study presents, for the first time, in vivo individual and mixture toxicity of four putative OBPs, that is, carbamazepine 10,11-epoxide, 10,11-Dihydrocarbamazepine, 1-(2-benzaldehyde)-4-hydro-(1H,3H)-quinazoline-2-one (BQM), and 1-(2-benzaldehyde)-(1H,3H)-quinazoline-2,4-dione (BQD) in developing zebrafish (Danio rerio) embryos. BQM and BQD were isolated from the ozonated solution as they were not commercially available. The study confirmed that the OBP mixture caused embryotoxic responses comparable to that of ozonated CBZ. Individual compound embryotoxicity assessment further revealed that BQM and BQD were the drivers of embryotoxicity. OBP chemical stability in ozonated CBZ water solution during 2 week dark storage at 22 degrees C was also assessed. The OBP concentrations remained over time, except for BQD which decreased by 94%. Meanwhile, ozonated CBZ persistently induced embryotoxicity over 2 week storage, potentially illustrating environmental concern.
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| 22. |
- Pohl, Johannes, et al.
(författare)
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Embryotoxicity of ozonated diclofenac, carbamazepine, and oxazepam in zebrafish (Danio rerio)
- 2019
-
Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 225, s. 191-199
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Tidskriftsartikel (refereegranskat)abstract
- Pharmaceutical residues are polluting the surface water environments worldwide. Sewage and wastewater treatment, therefore, needs to be improved in order to remove pharmaceutical residues from the effluent. One such treatment improvement is effluent ozonation. Even though ozonation has proven to be very efficient in reducing pharmaceutical parent compound concentrations in wastewater effluents, much remains unclear regarding potentially toxic ozonation by-product (OBP) formation. In this study, we sought to elucidate the aquatic toxicity of ozonated pharmaceuticals in zebrafish (Danio rerio) embryos in a static 144 h post fertilization (hpf) fish embryotoxicity (ZFET) assay. Three pharmaceuticals commonly detected in wastewater effluents, i.e. carbamazepine, diclofenac, and oxazepam, were selected for testing. Toxicity was assessed before and after 1 min ozonation (0.053 mg L-1 peak O-3 concentration) and 10 min ozonation (0.147 mg L-1 peak O-3 concentration). Chemical analysis showed that carbamazepine and diclofenac were largely removed by ozone (90 +/- 11% and 97 +/- 3.8%), whereas oxazepam was removed to a lesser extent (19 +/- 5.7%). The ZFET assay revealed diverging toxicities. Diclofenac embryotoxicity decreased with increasing ozonation. Oxazepam did not cause embryotoxicity in the ZFET assay either pre- or post ozonation, but larvae swimming activity was affected at 144 hpf. Carbamazepine embryotoxicity, on the other hand, increased with increasing ozonation. Chemical analysis showed the formation of two OBPs (carbamazepine-10,11-epoxide and 10,11-dihydrocarbamazepine), possibly explaining the increased embryotoxicity. The results of this study highlight the importance of new chemical and toxicological knowledge regarding the formation of OBPs in post-ozonated effluents. (C) 2019 The Authors. Published by Elsevier Ltd.
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| 23. |
- Rimayi, Cornelius, et al.
(författare)
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Contaminants of emerging concern in the Hartbeespoort Dam catchment and the uMngeni River estuary 2016 pollution incident, South Africa
- 2018
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 627, s. 1008-1017
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Tidskriftsartikel (refereegranskat)abstract
- A quantitative assessment of pollutants of emerging concern in the Hartbeespoort Damcatchment area was conducted using liquid chromatography-tandem mass spectrometry LC-MS/MS) to establish the occurrence, source and distribution of 15 environmental pollutants, including 10 pharmaceuticals, 1 pesticide and 4 steroid hormones. Seasonal sampling was conducted in the Hartbeespoort Lake using sub-surface grab sampling to determine the lake's ecological status and obtain data for establishment of progressive operational monitoring. The Jukskei River, which lies upstream of the Hartbeespoort Dam, was sampled in the winter season. Five year old carp Cyprinus carpio) and catfish Clarias gariepinus) were also sampled from the Hartbeespoort Dam to study bioaccumulation in biota as well as to estimate risk associated with fish consumption. In the Jukskei River, the main source of 11 emerging pollutants EPs) was identified as raw sewage overflow, with the highest Sigma 11 EP concentration of 593 ng L-1 being recorded at the Midrand point and the lowest Sigma 11 EP concentration of 164 ng L-1 at the N14 site located 1 km downstream of a large wastewater treatment plant. The Jukskei River was found to be the largest contributor of the emerging contaminants detected in the Hartbeespoort Dam. In the Hartbeespoort Dam EP concentrations were generally in the order efavirenz > nevirapine > carbamazepine > methocarbamol > bromacil > venlafaxine. Water and sediment were sampled from the uMngeni River estuary within 24 h after large volumes of an assortment of pharmaceuticalwaste had been discovered to bewashed into the river estuary after flash rainfall on 18 May 2016. Analytical results revealed high levels of some emerging pollutants in sediment samples, up to 81 ng g(-1) for nevirapine and 4 ng g(-1) for etilefrine HCL. This study shows that efavirenz, nevirapine, carbamazepine, methocarbamol, bromacil and venlafaxine are contaminants that require operational monitoring in South African urban waters.
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| 24. |
- Rimayi, Cornelius, et al.
(författare)
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Effects of environmentally relevant sub-chronic atrazine concentrations on African clawed frog (Xenopus laevis) survival, growth and male gonad development
- 2018
-
Ingår i: Aquatic Toxicology. - : Elsevier BV. - 0166-445X .- 1879-1514. ; 199, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- Sub-chronic toxicity of environmentally relevant atrazine concentrations on exposed tadpoles and adult male African clawed frogs (Xenopus laevis) was evaluated in a quality controlled laboratory for 90 days. The aim of this study was to determine the effects of atrazine on the survival, growth and gonad development of African clawed frogs. After exposure of tadpoles to atrazine concentrations of 0 (control), 0.01, 200 and 500 mu g L-1 in water, mortality rates of 0, 0, 3.3 and 70% respectively were recorded for the 90 day exposure period. Morphometry showed significantly reduced tadpole mass in the 500 mu g L-1 atrazine exposed tadpoles (p < 0.05). Light microscopy on testes of adult frogs exposed to the same atrazine concentrations using hematoxylin and eosin (H&E) and Van Gieson staining techniques revealed gonadal atrophy, disruption of germ cell lines, seminiferous tubule structure damage and formation of extensive connective tissue around seminiferous tubules of frogs exposed to 200 mu g L-1 and 500 mu g L-1 atrazine concentrations. Ultrastructural analysis of the cellular organelles using transmission electron microscopy (TEM) revealed significant amounts of damaged mitochondria in testosterone producing Leydig cells as well as Sertoli cells. Biochemical analysis revealed reduced serum testosterone levels in adult frogs at all exposure levels as well as presence of six atrazine metabolites in frog serum and liver. The results indicate that atrazine concentrations greater than the calculated LC50 of 343.7 mu g L-1 cause significant mortality in tadpoles, while concentrations >= 200 mu g L-1 adversely affect reproductive health of adult frogs and development of tadpoles sub-chronically exposed to atrazine.
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| 25. |
- Rimayi, Cornelius, et al.
(författare)
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Seasonal variation of chloro-s-triazines in the Hartbeespoort Dam catchment, South Africa
- 2018
-
Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 613, s. 472-482
-
Tidskriftsartikel (refereegranskat)abstract
- Seasonal variation of eight chloro-s-triazine herbicides and seven major atrazine and terbuthylazine degradation products was monitored in the Hartbeespoort Dam catchment using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS/MS). Lake, river and groundwater were sampled from the Hartbeespoort Dam catchment over four seasons and the downstream Jukskei River was monitored during the winter season. Triazine herbicide concentrations in the Hartbeespoort Dam were in the order atrazine > simazine > propazine > ametryn > prometryn throughout the four seasons sampled. Triazine herbicide concentrations in the Hartbeespoort Dam surface water were highest in summer and gradually decreased in successive seasons of autumn, winter and spring. Terbuthylazine was the only triazine herbicide detected at all sampling sites in the Jukskei River, though atrazine recorded much higher concentrations for the N14 and Kyalami sites, with concentrations of 923 and 210 ng L-1 respectively, compared to 134 and 74 ng L-1 for terbuthylazine. Analytical results in conjunction with river flow data indicate that the Jukskei and Crocodile Rivers contribute the greatest triazine herbicide loads into the Hartbeespoort Dam. No triazine herbicides were detected in the fish muscle tested, showing that bioaccumulation of triazine herbicides is negligible. Atrazine and terbuthylazine metabolites were detected in the fish muscle with deethylatrazine (DEA) being detected in both catfish and carp muscle at low concentrations of 0.2 and 0.3 ng g(-1), respectively. Desethylterbuthylazine (DET) was detected only in catfish at a concentration of 0.3 ng g(-1). With atrazine herbicide groundwater concentrations being >130 ng L-1 for all seasons and groundwater Sigma triazine herbicide concentrations ranging between 527 and 367 ng L-1, triazine compounds in the Hartbeespoort Dam catchment may pose a risk to humans and wildlife in light findings of endocrine and immune disrupting atrazine effects by various researchers.
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| 26. |
- Rimayi, Cornelius, et al.
(författare)
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Source characterisation and distribution of selected PCBs, PAHs and alkyl PAHs in sediments from the Klip and Jukskei Rivers, South Africa
- 2017
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Ingår i: Environmental Monitoring & Assessment. - : Springer Science and Business Media LLC. - 0167-6369 .- 1573-2959. ; 189:7
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Tidskriftsartikel (refereegranskat)abstract
- A study of the distribution of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) utilising 16 priority PAHs, benzo(e) pyrene, perylene, 19 alkylated PAHs and 31 ortho substituted PCBs in South Africa is presented. It was aimed to (a) deduce characteristic contamination patterns for both PCBs and PAHs and (b) provide the first comprehensive dataset for establishment of source characterisation of PCBs and PAHs. This is in line with new South African legislation on mandatory monitoring of PCB and PAH emissions. Bar charts, principal component analysis (PCA) and biplots were utilised to identify signature contamination patterns and distribution of PCBs and PAHs within the Jukskei and Klip Rivers. Sediments from the Jukskei and Klip River catchments both showed distinct contamination signatures for hexa to nonachlorinated PCBs, characteristic of contamination by Aroclor 1254 and 1260 technical mixtures. PCB signature patterns in order of abundance were 138 > 180 > 206 > 153 > 187 > 149 and 138 > 153 > 180 > 149 > 187 > 110 > 170 for the Jukskei and Klip River sediments, respectively. The upstream Alberton point had the highest Sigma 31 PCB and Sigma (parent+alkyl) PAH concentrations in the Klip River of 61 and 6000 mu g kg(-1) dry weight (dw), respectively. In the Jukskei River, the upstream Marlboro point had the highest Sigma 31 PCB concentration of 19 mu g kg(-1) dw and the N14 site recorded the highest Sigma(parent+alkyl) PAH concentration of 2750 mu g kg(-1) dw. PAH concentrations in both the Jukskei and Klip Rivers were significantly higher than the PCB concentrations. Fluoranthene, phenanthrene and pyrene were found in the highest concentrations in both the Jukskei and Klip River sediments. Both the Jukskei and Klip River sediments showed trends of a mixed pyrogenic-petrogenic PAH source contamination.
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| 27. |
- Spaan, Kyra, et al.
(författare)
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Effects of 25 thyroid hormone disruptors on zebrafish embryos : A literature review of potential biomarkers
- 2019
-
Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 656, s. 1238-1249
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Forskningsöversikt (refereegranskat)abstract
- It is estimated that many organic compounds found in our environment can interfere with the thyroid system and act as thyroid hormone (TH) disruptor. Despite that, there is a clear lack of assays to identify TH disruptors. Recently zebrafish embryos were suggested as screening tool to identify compounds which impact thyroid synthesis. Effects on hormone level, gene transcript expression, eye development and swim bladder inflation are suggested as potential biomarker for TH disruptors. In order to assess the applicability of these biomarkers we performed a literature review. The effects of 25 known TH disrupting compounds were compared between studies. The studies were limited to exposures with embryos prior 7 days of development. The different study designs and the lack of standardized methods complicated the comparison of the results. The most common responses were morphological alterations and gene transcript expression changes, but no specific biomarker for TH disruption could be identified. In studies addressing TH disruption behavioral effects were more commonly monitored than in studies not mentioning the TH pathway. TH disruption in developing zebrafish embryos might be caused by different modes of action e.g. disruption of follicle development, binding of TH, activation of TH receptors causing different effects. Timing of developmental processes in combination with exposure duration might also play a role. On the other side compound characteristics (uptake, stability, metabolization) could also cause differences between substances. Further studies are necessary to gain better understanding into the mechanisms of TH disruption in early zebrafish development.
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| 28. |
- 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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| 29. |
- Van Der Veen, Ike, et al.
(författare)
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Fate of Per- and Polyfluoroalkyl Substances from Durable Water-Repellent Clothing during Use
- 2022
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Ingår i: Environmental Science and Technology. - : American Chemical Society. - 0013-936X .- 1520-5851. ; 56:9, s. 5886-5897
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Tidskriftsartikel (refereegranskat)abstract
- To make outdoor clothing water- or dirt-repellent, durable water-repellent (DWR) coatings based on side-chain fluorinated polymers (SFPs) are used. During use of outdoor clothing, per- and polyfluoroalkyl substances (PFASs) can be emitted from the DWR to the environment. In this study, the effects of aging, washing, and tumble drying on the concentration of extractable PFASs in the DWR of perfluorohexane-based short-chain SFPs (FC-6 chemistry) and of perfluorooctane-based long-chain SFPs (FC-8 chemistry) were assessed. For this purpose, polyamide (PA) and polyester (PES) fabrics were coated with FC-6- and FC-8-based DWRs. Results show that aging of the coated fabrics causes an increase in concentration and formation of perfluoroalkyl acids (PFAAs). The effect of aging on the volatile PFASs depends on the type of fabric. Washing causes a decrease in PFAA concentrations, and in general, volatile PFASs are partly washed out of the textiles. However, washing can also increase the extractable concentration of volatile PFASs in the fabrics. This effect becomes stronger by a combination of aging and washing. Tumble drying does not affect the PFAS concentrations in textiles. In conclusion, aging and washing of fabrics coated with the DWR based on SFPs release PFASs to the environment.
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| 30. |
- van der Veen, Ike, et al.
(författare)
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The effect of weathering on per- and polyfluoroalkyl substances (PFASs) from durable water repellent (DWR) clothing
- 2020
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Ingår i: Chemosphere. - : Elsevier Ltd. - 0045-6535 .- 1879-1298. ; 249
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Tidskriftsartikel (refereegranskat)abstract
- To assess the effects of weathering on per- and polyfluoroalkyl substances (PFASs) from durable water repellent (DWR) clothing, thirteen commercial textile samples were exposed to elevated ultra violet (UV) radiation, humidity, and temperature in an aging device for 300 h, which mimics the lifespan of outdoor clothing. Before and after aging, the textile samples were extracted and analysed for the ionic PFASs (perfluoroalkyl acids (PFAAs), perfluorooctane sulfonamide (FOSA)) and volatile PFASs (fluorotelomer alcohols (FTOHs), acrylates (FTACs) and methacrylates (FTMACs)). Results showed that weathering can have an effect on PFASs used in DWR of outdoor clothing, both on the PFAS profile and on the measured concentrations. In most weathered samples the PFAA concentrations increased by 5- to more than 100-fold, while PFAAs not detected in the original textiles were detected in the weathered samples. DWR chemistries are based on side-chain fluorinated polymers. A possible explanation for the increase in concentration of the PFAAs is hydrolysis of the fluorotelomer based polymers (FTPs), or degradation of the FTOHs, which are used in the manufacturing of the FTPs. The concentrations of volatile PFASs also increased, by a factor up to 20. Suggested explanations are the degradation of the DWR polymers, making non-extractable fluorines extractable, or the transformation or degradation of unknown precursors. Further research is needed to unravel the details of these processes and to determine the transformation routes. This study shows that setting maximum tolerance limits only for a few individual PFASs is not sufficient to control these harmful substances in outdoor clothing.
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| 31. |
- Volchko, Yevheniya, 1979, et al.
(författare)
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Assessing costs and benefits of improved soil quality management in remediation projects : A study of an urban site contaminated with PAH and metals
- 2020
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 707
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Tidskriftsartikel (refereegranskat)abstract
- Contaminants in the soil may threaten soil functions (SFs) and, in turn, hinder the delivery of ecosystem services (ES). A framework for ecological risk assessments (ERAs) within the APPLICERA - APPLICable site-specific Environmental Risk Assessment research project promotes assessments that consider other soil quality parameters than only contaminant concentrations. The developed framework is: (i) able to differentiate the effects of contamination on SFs from the effects of other soil qualities essential for soil biota; and (ii) provides a robust basis for improved soil quality management in remediation projects. This study evaluates the socio-economic consequences of remediation alternatives stemming from a Tier 1 ERA that focusses on total contaminant concentrations and soil quality standards and a detailed, site-specific Tier 3 Triad approach that is based on the APPLICERA framework. The present study demonstrates how Tier 1 and Tier 3 ERAs differ in terms of the socio-economic consequences of their remediation actions, as well as presents a novel method for the semi-quantitative assessment of on-site ES. Although the presented Tier 3 ERA is more expensive and time-consuming than the more traditional Tier 1 ERA approach, it has the potential to lower the costs of remediation actions, decrease greenhouse gas emissions, reduce other environmental impacts, and minimise socio-economic losses. Furthermore, the remediation actions stemming from the Tier 3 ERA were predicted to exert far less negative ES effects than the actions proposed based on the results of the Tier 1 ERA.
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| 32. |
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| 33. |
- Weiss, Jana, 1973-
(författare)
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Human exposure to persistent organic pollutants : Illustrated by four case studies in Europe
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- An extensive use of chemicals in countless consumer products has resulted in human exposure to several persistent organic pollutants (POPs). Sufficient knowledge about their chemical composition properties and environmental faith is required, to be able to proper risk assess and regulate the substances. Significant data gaps exist regarding knowledge of actual exposure to humans and toxicological effect data.The objective of this thesis was to add human exposure data of a few POPs from four case studies. The analytes discussed in this thesis are polychlorinated dibenzo-p-dioxins and furans (PCDDs/PCDFs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCDD).Three European populations were studied. Milk was analysed from a group of women, who were accidentally exposed to high levels of 2,3,7,8-TetraCDD (TCDD) in Seveso, 1976. Still today, twice as high TCDD levels were recorded in the milk, compared to background concentrations. Serum was analysed from mothers and their infants from The Netherlands. Cord serum contained equal amounts of POPs as in mother’s blood, indicating non-hindered placenta transfer. Serum analysed from Swedish men and women with a high fish intake had elevated PCB and PCB metabolite (OH-PCB) levels. Additionally, butter was collected worldwide and shown to be a suitable matrix for dairy product survey of POPs.The exposure levels in the four papers were compared to recently reported exposure levels in Europe. It is indicated in the thesis that the PCDDs/PCDFs and PCBs toxic equivalency (TEQ) levels are of concern, i.e. the ratio between threshold levels for adverse health effects and TEQ exposure levels is lower than requested margin of safety. Average levels of PBDE/HBCDD in the European population are estimated to be of no concern today, but for individuals with intakes at the 95th percentile are the current margins of safety small.
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| 34. |
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| 35. |
- Weiss, Jana, et al.
(författare)
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Hydroxy-PCBs, PBDEs, and HBCDDs in serum from an elderly population of Swedish fishermen's wives and associations with bone density
- 2006
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Ingår i: Environmental Science & Technology. - : American Chemical Society (ACS). - 1520-5851 .- 0013-936X. ; 40:20, s. 6282-6289
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Tidskriftsartikel (refereegranskat)abstract
- Lack of human exposure data is frequently reported as a critical gap in risk assessments of environmental pollutants, especially regarding "new" pollutants. The objectives of this study were to assess serum levels of the persistent 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153), hydroxylated polychlorinated biphenyl metabolites (OH-PCBs), polybrominated diphenyl ethers (PBDEs), and hexabromocyclododecanes (HBCDDs) in a group of Swedish middle-aged and elderly women expected to be relatively highly exposed, and to evaluate the impact of potential determinants (e.g., fish intake, age) for the inter-individual variation, as well as to investigate the association between these pollutants and bone density. No associations were found between bone mineral density or biochemical markers of bone metabolism and the analyzed environmental pollutants. Relatively high levels of CB-153 (median 260 ng/g fat) and Sigma(3)-OH- PCBs (median 1.7 ng/mL serum), and low concentrations of Sigma 6PBDEs (median 3.6 ng/g fat) were determined. Total level of HBCDDs in serum was quantified by gas chromatography with mass spectrometric detection (median 0.5 ng/g fat). HBCDD diastereomeric and enantiomeric patterns were determined by liquid chromatography with mass spectrometric detection. The dominating stereoisomer was (-)alpha-HBCDD, but 1-3% of gamma-HBCDD was also detected in the serum samples.
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| 36. |
- Weiss, Jana, et al.
(författare)
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Identifiering av nya riskkemikalier och validering av exponerings index med fokus på människa
- 2022
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Syftet med denna studie var att finna strategier för att identifiera nya riskkemikalier som vi människor kan bli exponerade för, baserat på den information som finns i Svenska produktregistret (SE-PR). En kombination av information om den registrerade användningen av kemikalier, och modellerade egenskaper som kan förutspå persistens och huruvida kemikalierna är benägna att bioackumuleras i mänskligt blod och urin användes. Med denna strategi kunde olika listor av prioriterade kemikalier som kunde potentiellt vara riskkemikalier i blod och urin hos människa presenteras.Kort summerat: Kemikalier som är lätt biologiskt nedbrytbara bör övervakas i urin och icke biologiskt nedbrytbara bör analyseras i blod. Kemikalier med hög fördelningskoefficient för oktanol-luft (log KOA> 8) bör prioriteras för analys både i blod och urin. Fördelningskoefficienten för oktanol-vatten delar upp de prioriterade kemikalierna i tre grupper; opolära (log KOW> 6) och polära (log KOW 3,5-6) kemikalier för analys i blod, och polära (log KOW <4) kemikalier för analys i urin.Med denna strategi prioriterades syntetiska antioxidanter som potentiella riskkemikalier både i blod. Med riktad kemisk analys kunde sex antioxidanter detekteras i en pool av blodprover från människor som bor i Stockholmsregionen.
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| 37. |
- Weiss, Jana
(författare)
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Import, disposal, and health impacts of pesticides in the East Africa Rift (EAR) zone: A review on management and policy analysis
- 2018
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Ingår i: Crop Protection. - : Elsevier BV. - 0261-2194 .- 1873-6904. ; 112, s. 322-331
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Forskningsöversikt (refereegranskat)abstract
- East Africa Rift (EAR) zone countries, such as Ethiopia, Tanzania, Kenya, and Uganda are among the least developed countries in the world. Agricultural activities are the main source of their economy and huge amounts of pesticides have been imported for decades to protect crops from damage by pests and diseases. Some of these pesticides expired in storage before they were used and their disposal became a major problem. Further, these countries declare different policies related to pesticide management. This study reviews the relevant literature about import, disposal and health impacts of pesticides together with different related policies. Web of Science, Google Scholar, and Google were used as the main sources of information. Records show the increases in the import of pesticides in Ethiopia from 2013 to 2016, in Tanzania from 2006 to 2011, in Kenya from 2008 to 2015, and in Uganda from 1980 to 2004. Disposing of obsolete pesticides is very costly and needs proper facilities. Therefore, EAR countries transport these pesticides to European countries for incineration. For example, Ethiopia disposed of 1574.5 and 926 tonnes of obsolete pesticides in collaboration with the FAO. Acute and passive pesticide poisoning occurrences are also discussed in the review. The paper also highlights the policies so far stated. However, these policies lack proper implementation. Therefore, this study suggests EAR countries should use alternative methods to protect crops from the damage caused by pests and diseases, which could reduce the excessive import of pesticides. Similarly, training should also be given to all stakeholders to ensure implementation of all policies.
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| 38. |
- Weiss, Jana M, et al.
(författare)
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Competitive Binding of Poly- and Perfluorinated Compounds to the Thyroid Hormone Transport Protein Transthyretin
- 2009
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Ingår i: Toxicological sciences : an official journal of the Society of Toxicology. - : Oxford University Press of the Society of Toxicology. - 1096-0929. ; 109:2, s. 206-16
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Tidskriftsartikel (refereegranskat)abstract
- Due to their unique surfactant properties, poly- and perfluorinated compounds (PFCs) have been extensively used, and can be found all over the environment.. Concern about their environmental fate and toxicological properties have initiated several research projects. In the present study, we investigated if PFCs can compete with thyroxin (T4, i.e. the transport form of thyroid hormone) for binding to the human thyroid hormone transport protein transthyretin (TTR). Such competitive capacity may lead to decreased thyroid hormone levels as previously reported for animals exposed to PFCs. Twenty four PFCs, together with six structurally similar natural fatty acids, were tested for binding capacity in a radioligand binding assay. The binding potency decreased in the order: PFHxS>PFOS/PFOA>PFHpA>L-PFOSi>PFNA, with TTR binding potencies 12.5-50 times lower than the natural ligand thyroxine (T4). Some lower molecular weight compounds with structural similarity to these PFCs were >100 times less potent than T4. Simple descriptors based on the two dimensional molecular structures of the compounds were used to visualize the chemical variation and to model the structure-activity relationship for the competitive potencies of the TTR-binding compounds. The models indicated the dependence on molecular size and functional group(s), but demanded a more detailed description of the chemical properties and data for validation and further QSAR development. Competitive binding of PFCs to TTR as observed for human TTR in the present study, may explain altered thyroid hormone levels described for PFC-exposed rats and monkeys. Median human blood levels of the most potent TTR-binding PFCs are 1-2 orders of magnitude lower than IC50-values determined in the present study. In addition, this study contributes to the understanding of the bioaccumulation of PFCs in man and possibly in other wildlife species.
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| 39. |
- Weiss, Jana M., et al.
(författare)
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Daily intake of phthalates, MEHP, and DINCH by ingestion and inhalation
- 2018
-
Ingår i: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 208, s. 40-49
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Tidskriftsartikel (refereegranskat)abstract
- Phthalate esters, suspected endocrine disrupting chemicals, are used in a wide range of applications. Because phthalate esters are not covalently bound, they can easily leach into the indoor environment and associate to dust particles. Thus, exposure may occur through inhalation, ingestion, or contact with the skin. However, it is unclear to what degree indoor dust contributes to the daily intake of phthalate esters.This study investigates household dust as an exposure pathway for seven phthalate esters, the monoester MEHP, and the plasticizer DINCH. Household dust collected from children's sleeping rooms and from living rooms were analysed using gas and liquid chromatography tandem mass spectrometry. To compare two exposure pathways, different dust particle sizes were generated: a respirable fraction (<5 mu m) and an ingested particle fraction in the anticipated size range of skin adherence (<75 mu m). Modelling of dust inhalation and ingestion showed that the daily intake of dust-bound phthalate esters was likely to be 2 times (inhalation) to 12 times (ingestion) higher for 21-month-old children than for adults. These children's daily uptake of phthalate esters was 40-140 times higher through ingestion than inhalation. Furthermore, dust may be an exposure pathway for phthalate esters as well as for MEHP. Therefore, phthalate monoesters could be environmental contaminants of their own and need to be considered in health risk assessments. (C) 2018 Elsevier Ltd. All rights reserved.
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| 40. |
- Weiss, Jana M., et al.
(författare)
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Per- and polyfluoroalkyl substances (PFASs) in Swedish household dust and exposure of pet cats
- 2021
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Ingår i: Environmental Science and Pollution Research. - : Springer Science and Business Media LLC. - 0944-1344 .- 1614-7499. ; :28, s. 39001-39013
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Tidskriftsartikel (refereegranskat)abstract
- Per- and polyfluoroalkyl substances (PFASs) are used in a wide range of products and have been found ubiquitously in our indoor environment, and there is evidence that exposure to PFAS can lead to adverse endocrine effects, such as thyroid hormone disruption. Pet cats have a high dust intake due to their grooming behavior and have been shown to be a suitable sentinel species for assessment of toddler's exposure. Here we used paired household dust (n=46) and cat serum (n=27) samples to establish whether dust is a relevant exposure pathway to PFASs. An analytical method for PFAS analysis was optimized using a low volume of cat serum samples, combining solid-phase extraction and online sample cleanup. Dust was extracted with methanol by sonication and cleaned up by addition of active carbon. In total, 27 PFASs were analyzed by liquid chromatography/mass spectrometry analysis. The correlation between PFAS levels in dust and serum, serum lipids and thyroid hormone levels, and PFAS levels in dust between different rooms were statistically evaluated. PFOS and PFDA could be quantified in all cat serum samples (median 2300 pg/mL and 430 pg/mL, respectively), followed by PFOA (median 1100 pg/mL), quantified in 96% of the samples. The levels of 6:2 and 8:2 diPAPs were determined in 65% and 92% of the serum samples, respectively, and were an order of magnitude lower (1.4-160 pg/mL). Household dust on the other hand was dominated by 6:2 and 8:2 diPAPs, with a median of 65 ng/g dust and 49 ng/g dust, respectively. PFOS (median 13 ng/g dust) and PFOA (median 9 ng/g dust) were quantified in 93% of the dust samples. Only eight PFASs were detected (>LOD) in at least 50% of the samples of both matrices and could be paired. Significant correlations between cat serum and dust were found for PFOA (r(S)=0.32, p<0.049) and PFUnDA (r(S)=0.55, p<0.001). Significant positive correlations were found between serum total thyroxine (r(S)=0.11, p<0.05) and PFNA and between serum cholesterol and PFHpA (r(S)=0.46, p<0.01), PFUnDA (r(S)=0.40, p<0.05), PFDoDA (r(S)=0.44, p<0.01), and sum PFAS (r(S)=0.48, p<0.01). In conclusion, this study confirmed that dust is a relevant exposure pathway for the ingestion of some PFASs for cats, and the serum levels of PFASs could be of relevance for the cat's health.
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| 41. |
- 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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| 42. |
- Weiss, Jana, et al.
(författare)
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Screening of polyfluoroalkyl substances (PFASs), including fluorinated organophosphates in Skellefteå municipality
- 2019
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- SammanfattningResultaten visar att många fler PFAS kongener kan bestämmas i dammprover än i ytvatten ochavloppsvattenprover. I damm kvantifierades i minst ett prov 36 PFAS, jämfört med 6 PFAS i ytvattenoch 8 PFAS i avloppsvatten. Det vara stora variationer i PFAS-koncentrationerna i dammprover mellanindustrier med olika aktiviteter, vilket mycket väl återspeglar en användning av PFAS-innehållandeprodukter. Nivåerna var generellt högre i industriellt damm än vad som uppmättes tidigare ihushållsdamm. Tidigare observerade höga PFPA- och PFPIA-koncentrationerna kunde inte bekräftas,varken i damm eller i vattenproverna. Omfattande metodvalideringsarbete indikerade att dammrepresenterar en exceptionellt komplex matris, vilket kan vara en del av förklaringen. Därmed skarapporterad damm koncentrationer tolkas med varsamhet och uppföljande studier behövs för attbekräfta observationer.PFAS-nivåerna i ytvattnet var generellt under kvantifieringsnivåer. Endast 6:2 FTSA hade förhöjdanivåer i några få prover. Källan till 6:2 FTSA är inte känd. Som förväntat kunde det konstateras attSkellefteå flygplats släpper ut PFAS som kommer från brandbekämpningsskum, främst PFOS ochPFHxS. Kvantifierbara nivåer av PFAS hittades även i ett prov nedströms samhället Kusmark, medokänd källa.En viktig slutsats i studien var att många företrädare för industrin inte kände till omfattningen av PFASföroreningi sina anläggningar. Ingen av de inkluderade industrierna rapporterade användningen avPFAS, medan det framgår av litteraturgranskningen och den observerade PFAS-koncentrationen idammproverna, att PFASs hanteras i respektive anläggning. Detta belyser behovet av att förbättramedvetenheten om källorna genom bättre rapportering av innehållet i produkter. Det är viktigt attförbättra informationen om vilka PFAS som finns i produkter, och därmed ytterligare undersökapotentiella exponeringskällor. Flera toxikologiska studier har gjorts på det reglerade PFOS och PFOA,medan för andra PFASs är informationen möjliga hälsoeffekter ytterst begränsat.
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| 43. |
- Wiklund, Linus, et al.
(författare)
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Exploring a mechanism-based approach for the identification of endocrine disruptors using Adverse Outcome Pathways (AOPs) and New Approach Methodologies (NAMs) : A perfluorooctane sulfonic acid case study
- 2024
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Ingår i: Toxicology. - 0300-483X .- 1879-3185. ; 504
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Tidskriftsartikel (refereegranskat)abstract
- Endocrine disruptors (EDs) pose a serious threat to human health and the environment and require a comprehensive evaluation to be identified. The identification of EDs require a substantial amount of data, both in vitro and in vivo, due to the current scientific criteria in the EU. At the same time, the EU strives to reduce animal testing due to concerns regarding animal welfare and sensitivity of animal studies to adequately detect adverse effects relevant for human health. Perfluorooctane sulfonic acid (PFOS) is a persistent organic pollutant that is suspected to be an ED based on academic research, however it is not identified as such from a regulatory perspective. It has previously been shown that PFOS has the potential to cause neurotoxicity as well as affect the thyroid system, and it is known that specific thyroid hormone levels are critical in the development of the brain during. In this work, the aim was to evaluate a mechanism-based approach to identify ED properties of PFOS based on the Adverse Outcome Pathway (AOP) framework and using New Approach Methods (NAMs), by comparing this approach to an ED assessment based on the currently available guidance document. An AOP network (AOPN) was generated for the thyroid modality, and AOPs leading to developmental neurotoxicity (DNT) were identified. A literature search and screening process based on the AOPN, and systematic review methodology, was performed, followed by a rigorous Weight-of-Evidence (WoE) assessment. Evidence was mapped back onto the AOPN used for the literature search, to identify possible endocrine Modes-of-Action (MoAs) for PFOS and data gaps in the two assessments. It could be concluded that PFOS fulfils the criteria for ED classification in the standard ED assessment, but not in the mechanism-based assessment. The need for quantitative information, such as quantitative AOPs, for the mechanism-based approach is discussed. The possibility of a directly neurotoxic alternative MoA was also highlighted based on available in vitro data. Opportunities and challenges with implementing AOPs and NAMs into the regulatory assessment of EDs, and assessing hazard in the Next Generation Risk Assessment, is discussed. This case study exploring the mechanism-based approach to ED identification represents an important step toward more accurate and predictive assessment of EDs based on AOPs and NAMs, and to the Next Generation Risk Assessment (NGRA) concept.
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| 44. |
- Zhang, Jin, et al.
(författare)
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In Silico Approach To Identify Potential Thyroid Hormone Disruptors among Currently Known Dust Contaminants and Their Metabolites
- 2015
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 49:16, s. 10099-10107
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Tidskriftsartikel (refereegranskat)abstract
- Thyroid hormone disrupting chemicals (THDCs) interfere with the thyroid hormone system and may induce multiple severe physiological disorders. Indoor dust ingestion is a major route of THDCs exposure in humans, and one of the molecular targets of these chemicals is the hormone transporter transthyretin (TTR). To virtually screen indoor dust contaminants and their metabolites for THDCs targeting TTR, we developed a quantitative structure activity relationship (QSAR) classification model. The QSAR model was applied to an in-house database including 485 organic dust contaminants reported from literature data and their 433 in silico derived metabolites. The model predicted 37 (7.6%) dust contaminants and 230 (53.1%) metabolites as potential TTR binders. Four new THDCs were identified after testing 23 selected parent dust contaminants in a radio-ligand TTR binding assay; 2,2',4,4'-tetrahydroxybenzophenone, perfluoroheptanesulfonic acid, 3,5,6-trichloro-2-pyridinol, and 2,4,5-trichlorophenoxyacetic acid. These chemicals competitively bind to TTR with 50% inhibition (IC50) values at or below 10 mu M. Molecular docking studies suggested that these THDCs interacted similarly with TTR via the residue Ser117A, but their binding poses were dissimilar to the endogenous ligand T4. This study identified new THDCs using an in silico approach in combination with bioassay testing and highlighted the importance of metabolic activation for TTR binding.
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