| 1. |
- Adolfsson-Erici, Margaretha, et al.
(författare)
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A flow-through passive dosing system for continuously supplying aqueous solutions of hydrophobic chemicals to bioconcentration and aquatic toxicity tests
- 2012
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 86:6, s. 593-599
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Tidskriftsartikel (refereegranskat)abstract
- A continuous supply of water with defined stable concentrations of hydrophobic chemicals is a requirement in a range of laboratory tests such as the OECD 305 protocol for determining the bioconcentration factor in fish. Satisfying this requirement continues to be a challenge, particularly for hydrophobic chemicals. Here we present a novel solution based on equilibrium passive dosing. It employs a commercially available unit consisting of similar to 16000 polydimethylsiloxane (PDMS) tubes connected to two manifolds. The chemicals are loaded into the unit by repeatedly perfusing it with a methanol solution of the substances that is progressively diluted with water. Thereafter the unit is perfused with water and the chemicals partition from the unit into the water. The system was tested with nine chemicals with logK(ow) ranging from 4.1 to 6.3. The aqueous concentrations generated were shown to be largely independent of the water flow rate, and the unit to unit reproducibility was within a factor of similar to 2. In continuous flow experiments the aqueous concentrations of most of the study chemicals remained constant over 8 d. A model was assembled that allows prediction of the operating characteristics of the system from the logKow or PDMS/water partition coefficient of the chemical. The system is a simple, safe, predictable and flexible tool that generates stable aqueous concentrations of hydrophobic chemicals.
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| 2. |
- Adolfsson-Erici, Margaretha, 1950-
(författare)
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Fish bile in environmental analysis
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This work explores the usefulness of fish bile analysis in combination with biomarkers for identifying and evaluating new environmental contaminants in the aquatic environment. It illustrates how bile analysis can be used together with biomarkers to assess the causes of estrogenic effects, to identify chemicals in the aquatic environment that are taken up by fish, and to monitor environmental exposure.In a first application, fish exposed to sewage treatment plant effluent were studied. Elevated levels of vitellogenin in the exposed fish demonstrated that estrogenic effects occurred. Several estrogen disrupting substances were identified in the fish bile, and analysis of water samples confirmed that these substances were present in the effluent. The synthetic estrogen 17a-ethinylestradiol, which is known to be present in sewage treatment plant effluent, was shown for the first time to be taken up by fish. Considering the reported potencies of the detected substances, it was concluded that 17a-ethinylestradiol was the major contributor to the estrogenic effects.Chemical analysis of bile was used to identify rubber additives that were released from tires immersed in water. The bile of rainbow trout held in the water contained high levels of metabolites of PAHs and aromatic nitrogen compounds. Several biomarkers were also measured in the exposed fish, and EROD induction and oxidative stress were observed. Based on the bile analysis observations together with knowledge of toxicological mechanisms, it was postulated that the EROD induction was due to the PAHs, while aromatic nitrogen compounds caused the oxidative stress.Resin acids in fish bile proved to be a good indicator of exposure in a chronic long-term study of rainbow trout exposed to effluent from a total chlorine free (TCF) pulp mill. Elevated levels of GST (gluthatione-S-transferase) and GR (gluthatione reductase) activity, and the presence of DNA adducts after a two month recovery period, indicated that compounds in the pulp mill effluents have persistent effects. In addition to characterising the exposure of the fish to the effluent, the analysis of the resin acids in the bile provided evidence of accidents in the pulp mill that the existing process monitoring system had not detected.Resin acids in bile were also found to be a valuable indicator of exposure to pulp mill effluents for eelpout living in the Baltic Sea. A correlation between resin acid levels in bile and skewed sex ratios provided an important link in the chain of evidence that substances in the pulp mill effluents cause male bias of the eelpout embryos.A particularly good example of the potential of bile analysis was the identification of a previously unknown environmental contaminant. A large peak was observed in the bile extracts of fish that had been exposed to sewage treatment plant effluent. This peak was identified as triclosan, which demonstrated its presence in sewage treatment plant effluent. Other work went on to show that it is a common contaminant of the aquatic environment. The ability of fish to concentrate contaminant metabolites in bile to levels very much higher than in the environment, and the comparatively low levels of analytic interferences, make bile a particularly attractive matrix to search for new, unknown organic pollutants
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| 3. |
- Adolfsson-Erici, Margaretha, et al.
(författare)
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In-vivo passive sampling to measure elimination kinetics in bioaccumulation tests
- 2012
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 88:1, s. 62-68
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Tidskriftsartikel (refereegranskat)abstract
- The application of in-tissue passive sampling to quantify chemical kinetics in fish bioconcentration experiments was investigated. A passive sampler consisting of an acupuncture needle covered with a PDMS tube was developed together with a method for its deployment in rainbow trout. The time to steady state for chemical uptake into the passive sampler was >1 d, so it was employed as a kinetically limited sampler with a deployment time of 2 h. The passive sampler was employed in parallel with the established whole tissue extraction method to study the elimination kinetics of 10 diverse chemicals in rainbow trout. 4-n-nonylphenol and 2,4,6-tri-tert-butylphenol were close to or below the limit of quantification in the sampler. For chlorpyrifos, musk xylene, hexachlorobenzene, 2,5-dichlorobiphenyl and p,p'-DDT. the elimination rate constants determined with the passive sampler method and the established method agreed within 18%. Poorer agreement (35%) was observed for 2,3,4-trichloroanisole and p-diisopropylbenzene because fewer data were obtained with the passive sampling method due to its lower sensitivity. The work shows that in-tissue passive sampling can be employed to measure contaminant elimination kinetics in fish. This opens up the possibility of studying contaminant kinetics in individual fish, thereby reducing the fish requirements and analytical costs for the determination of bioconcentration factors.
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| 4. |
- Adolfsson-Erici, Margaretha, et al.
(författare)
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Internal Benchmarking Improves Precision and Reduces Animal Requirements for Determination of Fish Bioconcentration Factors
- 2012
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 46:15, s. 8205-8211
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Tidskriftsartikel (refereegranskat)abstract
- The enactment of new chemical regulations has generated a large need for the measurement of the fish bioconcentration factor (BCF). Past experience shows that the BCF determination lacks precision, requires large numbers of fish, and is costly. A new protocol was tested that shortens the experiment from up to 12 weeks for existing protocols to 2 weeks and reduces the number of fish by a factor of 5, while introducing internal benchmarking for the BCF determination. Rainbow trout were simultaneously exposed to 11 chemicals. The BCFs were quantified using one of the test chemicals, musk xylene, as a benchmark. These were compared with BCFs measured in a parallel experiment based on the OECD 305 guideline. The agreement was <20% for five chemicals and between 20%-25% for two further, while two chemicals lay outside the BCF operating window of the experiment and one was lost due to analytical difficulties. This agreement is better than that observed in a BCF Gold Standard Database. Internal benchmarking allows the improvement of the precision of BCF determination in parallel to large reduction in costs and fish requirements.
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| 5. |
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| 6. |
- Adolfsson-Erici, Margaretha, et al.
(författare)
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Measuring bioconcentration factors in fish using exposure to multiple chemicals and internal benchmarking to correct for growth dilution
- 2012
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Ingår i: Environmental Toxicology and Chemistry. - : Wiley. - 0730-7268 .- 1552-8618. ; 31:8, s. 1853-1860
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Tidskriftsartikel (refereegranskat)abstract
- Modern chemical legislation requires measuring the bioconcentration factor (BCF) of large numbers of chemicals in fish. The BCF must be corrected for growth dilution, because fish growth rates vary between laboratories. Two hypotheses were tested: (1) that BCFs of multiple chemicals can be measured simultaneously in one experiment, and (2) that internal benchmarking using a conservative test substance in the chemical mixture can be used to correct for growth dilution. Bioconcentration experiments were conducted following major elements of the OECD 305 guideline. Fish were simultaneously exposed to 11 chemicals selected to cover a range of BCFs and susceptibility to biotransformation. A method was developed to calculate the growth-corrected elimination rate constant from the concentration ratio of the analyte and a benchmarking chemical for which growth dilution dominated other elimination mechanisms. This method was applied to the experimental data using hexachlorobenzene as the benchmarking chemical. The growth dilution correction lowered the apparent elimination rate constants by between 5% and a factor of four for eight chemicals, while for two chemicals the growth-corrected elimination rate constant was not significantly different from zero. The benchmarking method reduced the uncertainty in the elimination rate constant compared to the existing method for growth dilution correction. The BCFs from exposing fish to 10 chemicals at once were consistent with BCF values from single-chemical exposures from the literature, supporting hypothesis 1. Environ. Toxicol. Chem. 2012; 31: 18531860. (c) 2012 SETAC
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| 7. |
- Adolfsson-Erici, Margaretha, et al.
(författare)
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Undersökning av det syntetiska sötningsmedlet sukralos med avseende på eventuella ekotoxikologiska effekter
- 2001
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Två släkten av kräftdjur: Nitocra spinipes och Gammarus oceanicus resp zaddachiexponerades för sukralos i ekotoxikologiskt relevanta koncentrationer i kroniska tester. Viarbetade utifrån följande hypoteser: skalömsning hos kräftdjur störs av höga halter sukralos iomgivande vatten samt att sukralos inte biokoncentreras i exponerade organismer.Långtidsexponering resulterade i högre dödlighet hos juvenila gammarider. Sukralos syntesinte påverka skalömsningstiden för de adulta honorna i ett pre-copula experiment. Inga teckenpå biokoncentrering kunde märkas. Exponeringen av Nitocra resulterade i att de djur somexponerats för de lägre koncentrationerna av sukralos var längre jämfört med kontrolldjurenmedan för individer exponerade för de högre koncentrationerna minskade längden medökande sukraloskoncentration. De kortaste individerna återfanns i den positiva kontrollen ochhade exponerats för 50 μg/L lindan. RNA-innehållet varierade mellan exponeringarna och denvar lägst i 500μg/L och högst i 5000 μg/L exponeringen Vi fann däremot inget signifikantsamband mellan RNA-innehåll och tillväxthastighet hos Nitocra. Detta kan möjligen vara eneffekt av sukralosexponering, eftersom linjära responser från tidigare experiment har noterats.Inga skillnader avseende medelutvecklingstiden var signifikanta. Renat avloppsvatten frånHenriksalsverken innehöll relativt höga koncentrationer sukralos liksom ytvatten från trereningsverksrecipienter.
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| 8. |
- Chen, Chang-Er L., et al.
(författare)
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Deriving in Vivo Bioconcentration Factors of a Mixture of Fragrance Ingredients Using a Single Dietary Exposure and Internal Benchmarking
- 2018
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 52:9, s. 5227-5235
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Tidskriftsartikel (refereegranskat)abstract
- Chemicals in mixtures that are hydrophobic with Log K-OW > 4 are potentially bioaccumulative. Here, we evaluate an abbreviated and benchmarked in vivo BCF measurement methodology by exposing rainbow trout to a mixture of eight test chemicals found in fragrance substances and three benchmark chemicals (musk xylene (MX), hexachlorobenzene (HCB) and PCB52) via a single contaminated feeding event followed by a 28-day depuration period. Concentrations of HCB and PCB52 in fish did not decline significantly (their apparent depuration rate constants, k(T), were close to zero), whereas k(T) for MX was 0.022 d(-1). The test chemicals were eliminated much more rapidly than the benchmark chemicals (k(T) > 0.117 d(-1)). The bioconcentration factors (BCFA) for the test chemicals were in the range of 273 L kg(-1) (8-cyclohexadecen-1-one (globanone)) to 1183 L kg(-1) (alpha-pinene); the benchmarked BCFs (BCFG) calculated relative to HCB ranged from 238 L kg(-1) (globanone) to 1147 L kg(-1) (alpha-pinene). BCFG were not significantly different from BCFA but had smaller standard errors. BCFs derived here agreed well with values previously measured using the OECD 305 test protocol. We conclude that it will be feasible to derive BCFs of chemicals in mixtures using a single dietary exposure and chemical benchmarking.
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| 9. |
- Chen, Changer Long, et al.
(författare)
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Determination of fragrance ingredients in fish by ultrasound-assisted extraction followed by purge & trap
- 2017
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Ingår i: Analytical Methods. - : Royal Society of Chemistry (RSC). - 1759-9660 .- 1759-9679. ; 9:15, s. 2237-2245
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Tidskriftsartikel (refereegranskat)abstract
- Fragrance materials are widely used in household and personal care products in applications that can lead to emissions into the aquatic environment. Assessing the potential of fragrance materials to bioaccumulate in fish in in vivo laboratory studies requires a reliable analytical method for determining the concentrations of chemical substances in fish tissue. Here, we present an analytical method for simultaneously measuring a group of model chemicals that are representative of chemicals found in fragrance materials in rainbow trout. This method involves ultrasound-assisted extraction (UAE) followed by enrichment of the fragrance ingredients using a purge & trap system. Nine fragrance ingredients including semi-volatile and volatile compounds were selected as model substances for method development. Homogenised whole rainbow trout subsamples were spiked with these nine model fragrance ingredients, hexachlorobenzene (HCB) and 2,2',5,5'-tetrachlorobiphenyl (PCB52). The targeted chemicals were extracted from the fish tissue using acetonitrile in an ultrasonic bath; after solvent exchange to hexane, they were extracted into the gas phase by heating the samples and purging with nitrogen and trapped on a solid-phase extraction (SPE) cartridge. Finally, these chemicals were eluted with hexane from the SPE column and analysed using gas chromatography-mass spectrometry (GC-MS). The proposed method has been evaluated for blanks, spiked recoveries and precision, which are all acceptable. We believe that the method presented here is generally applicable for analysis of acid-sensitive volatile and semi-volatile organic chemicals in fish and provides the basis to conduct in vivo bioaccumulation studies of fragrance materials.
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| 10. |
- Ek, Caroline, et al.
(författare)
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Growth Retardation and Altered Isotope Composition As Delayed Effects of PCB Exposure in Daphnia magna
- 2016
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 50:15, s. 8296-8304
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Tidskriftsartikel (refereegranskat)abstract
- Trophic magnification factor (TMF) analysis employs stable isotope signatures to derive biomagnification potential for environmental contaminants. This approach relies on species delta N-15 values aligning with their trophic position (TP). This, however, may not always be true, because toxic exposure can alter growth and isotope allocation patterns. Here, effects of PCB exposure (mixture of PCB18, PCB40, PCB128, and PCB209) on delta N-15 and delta C-13 as well as processes driving these effects were explored using the cladoceran Daphnia magna. A two-part experiment assessed effects of toxic exposure during and after exposure; juvenile daphnids were exposed during 3 days (accumulation phase) and then allowed to depurate for 4 days (depuration phase). No effects on survival, growth, carbon and nitrogen content, and stable isotope composition were observed after the accumulation phase, whereas significant changes were detected in adults after the depuration phase. In particular, a significantly lower nitrogen content and a growth inhibition were observed, with a concomitant increase in delta N-15 (+0.1 parts per thousand) and decrease in delta C-13 (-0.1 parts per thousand). Although of low magnitude, these changes followed the predicted direction indicating that sublethal effects of contaminant exposure can lead to overestimation of TP and hence underestimated TMF.
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