| 1. |
- Carney Almroth, Bethanie, 1974, et al.
(författare)
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Assessing the effects of textile leachates in fish using multiple testing methods: From gene expression to behavior
- 2021
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Ingår i: Ecotoxicology and Environmental Safety. - : Elsevier BV. - 0147-6513 .- 1090-2414. ; 207
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Tidskriftsartikel (refereegranskat)abstract
- The textile industry, while of major importance in the world economy, is a toxic industry utilizing and emitting thousands of chemical substances into the aquatic environment. The aim of this project was to study the potentially harmful effects associated with the leaching of chemical residues from three different types of textiles: sportswear, children’s bath towels, and denim using different fish models (cell lines, fish larvae and juvenile fish). A combination of in vitro and in vivo test systems was used. Numerous biomarkers, ranging from gene expression, cytotoxicity and biochemical analysis to behavior, were measured to detect effects of leached chemicals. Principle findings indicate that leachates from all three types of textiles induced cytotoxicity on fish cell lines (RTgill-W1). Leachates from sportswear and towels induced mortality in zebrafish embryos, and chemical residues from sportswear reduced locomotion responses in developing larval fish. Sportswear leachate increased Cyp1a mRNA expression and EROD activity in liver of exposed brown trout. Leachates from towels induced EROD activity and VTG in rainbow trout, and these effects were mitigated by the temperature of the extraction process. All indicators of toxicity tested showed that exposure to textile leachate can cause adverse reactions in fish. These findings suggested that chemical leaching from textiles from domestic households could pose an ecotoxicological threat to the health of the aquatic environment.
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| 2. |
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| 3. |
- Asnicar, Davide, et al.
(författare)
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Sand Goby : An Ecologically Relevant Species for Behavioural Ecotoxicology
- 2018
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Ingår i: Fishes. - : MDPI. - 2410-3888. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Locomotion-based behavioural endpoints have been suggested as suitable sublethal endpoints for human and environmental hazard assessment, as well as for biomonitoring applications. Larval stages of the sand goby (Pomatoschistus minutus) possess a number of attractive qualities for experimental testing that make it a promising species in behavioural ecotoxicology. Here, we present a study aimed at developing a toolkit for using the sand goby as novel species for ecotoxicological studies and using locomotion as an alternative endpoint in toxicity testing. Exposure to three contaminants (copper (Cu), di-butyl phthalate (DBP) and perfluorooctanoic acid (PFOA) was tested in the early life stages of the sand goby and the locomotion patterns of the larvae were quantified using an automatic tracking system. In a photo-motor test, sand goby larvae displayed substantially higher activity in light than in dark cycles. Furthermore, all tested compounds exerted behavioural alterations, such as hypo- and hyperactivity. Our experimental results show that sand goby larvae produce robust and quantifiable locomotive responses, which could be used within an ecotoxicological context for assessing the behavioural toxicity of environmental pollutants, with particular relevance in the Nordic region. This study thus suggests that sand goby larvae have potential as an environmentally relevant species for behavioural ecotoxicology, and as such offer an alternative to standard model species.
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| 4. |
- Birgersson, Lina, 1989
(författare)
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Effects of mixtures of endocrine disrupting chemicals – Thyroid disruption and behavioural effects in fish models
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Wildlife and humans are continuously exposed to thousands of man-made compounds, including chemicals that are able to act as endocrine disruptors (EDCs). These pollutants are able to affect vital processes including brain development, reproduction, metabolism and growth. An organism can be especially sensitive to these chemicals if the exposure occurs during early developmental stages, at so-called “windows of exposure” when organs that rely on endocrine regulation are still being developed. EDCs and other pollutants are present in the environment as complex mixtures, which can be difficult to handle from a risk assessment point of view. It is therefore important to evaluate effects of EDC mixtures after exposure during early development. The majority of the work in the current thesis was done by exposure studies using zebrafish. These studies take place within the EDC-MixRisk project, where an interdisciplinary whole mixture approach is used to assess effects of human-relevant EDC mixtures. This thesis is focused on three of the mixtures designed and produced within the EDC-MixRisk project, based on chemicals measured in serum of pregnant women and associated with adverse effects on neurodevelopment (MIX N0) or negatively associated with birth weight (MIX G0 and MIX G1) in their children. Effects on behaviour and expression of genes related to the thyroid system were assessed in larval zebrafish after acute (48h) exposures using automatic locomotion tracking and qPCR. MIX N0, MIX G0 and MIX G1 were all found to significantly affect the locomotion of larval zebrafish at concentrations 100 times higher than the mean serum concentration measured in pregnant women (100X). Effects on thyroid receptor expression (thra and thrb) and deiodinases (dio1 and dio2) were also observed for MIX N0 and MIX G1 at this concentration. For MIX G0, effects on gene expression (thra, thrb and dio2) were found already at 0.01X–1X concentrations (i.e. up to 100 times lower than the mean concentrations measured in women). Next, we compared the two mixtures (MIX G0 and MIX G1) linked to adverse effect on growth by measuring locomotion over a longer period of time and found that the more complex MIX G1, which had the same total concentration as MIX G0 but consisted of more compounds, had an attenuated effect compared to MIX G0 immediately after exposure. However, when locomotion was measured one month later fish were still affected and moving less than compared to controls (hypoactive distance travelled) after MIX G1 exposure while MIX G0 no longer had an effect. We also assessed the impact of environmental enrichment (EE) on exposure to the EDC mixtures. Our results showed that the rearing environment can affect the outcome of behavioural assays later in life for zebrafish acutely exposed to EDC mixtures. Additionally, adult fish reared in a barren or enriched environment and thereafter exposed to EDC mixtures can respond differently in a behaviour assay. The final study included in this thesis was a field study of wild perch from sites in Sweden contaminated with known EDCs. We found that lifelong exposure to PFASs (one of the chemical classes present in the EDC mixtures described above) in a contaminated lake can affect both the thyroid system and immune defence in wild perch.
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| 5. |
- Birgersson, Lina, 1989, et al.
(författare)
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Thyroid function and immune status in perch (Perca fluviatilis) from lakes contaminated with PFASs or PCBs
- 2021
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Ingår i: Ecotoxicology and Environmental Safety. - : Elsevier BV. - 0147-6513 .- 1090-2414. ; 222
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Tidskriftsartikel (refereegranskat)abstract
- The environment contains a multitude of man-made chemicals, some of which can act as endocrine disruptors (EDCs), while others can be immunotoxic. We evaluated thyroid disruption and immunotoxic effects in wild female perch (Perca fluviatilis) collected from two contaminated areas in Sweden; one site contaminated with perand polyfluoroalkyl substances (PFASs) and two sites contaminated with polychlorinated biphenyls (PCBs), with one reference site included for each area. The hepatic mRNA expression of thyroid receptors alpha and beta, and the thyroid hormone metabolising iodothyronine deiodinases (dio1, dio2 and dio3) were measured using real-time PCR, while the levels of thyroid hormone T3 in plasma was analysed using a radioimmunoassay. In addition, lymphocytes, granulocytes, and thrombocytes were counted microscopically. Our results showed lower levels of T3 as well as lower amounts of lymphocytes and granulocytes in perch collected from the PFAS-contaminated site compared to reference sites. In addition, expressions of mRNA coding for thyroid hormone metabolising enzymes (dio2 and dio3) and thyroid receptor alpha (thra) were significantly different in these fish compared to their reference site. For perch collected at the two PCB-contaminated sites, there were no significant differences in T3 levels or in expression levels of the thyroid-related genes, compared to the reference fish. Fish from one of the PCB-contaminated sites had higher levels of thrombocytes compared with both the second PCB lake and their reference lake; hence PCBs are unlikely to be the cause of this effect. The current study suggests that lifelong exposure to PFASs could affect both the thyroid hormone status and immune defence of perch in the wild.
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| 6. |
- Caporale, N., et al.
(författare)
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From cohorts to molecules: Adverse impacts of endocrine disrupting mixtures
- 2022
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 375:6582
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Tidskriftsartikel (refereegranskat)abstract
- Convergent evidence associates exposure to endocrine disrupting chemicals (EDCs) with major human diseases, even at regulation-compliant concentrations. This might be because humans are exposed to EDC mixtures, whereas chemical regulation is based on a risk assessment of individual compounds. Here, we developed a mixture-centered risk assessment strategy that integrates epidemiological and experimental evidence. We identified that exposure to an EDC mixture in early pregnancy is associated with language delay in offspring. At human-relevant concentrations, this mixture disrupted hormone-regulated and disease-relevant regulatory networks in human brain organoids and in the model organisms Xenopus leavis and Danio rerio, as well as behavioral responses. Reinterrogating epidemiological data, we found that up to 54% of the children had prenatal exposures above experimentally derived levels of concern, reaching, for the upper decile compared with the lowest decile of exposure, a 3.3 times higher risk of language delay. © 2022 American Association for the Advancement of Science. All rights reserved.
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| 7. |
- Goodrich, H. R., et al.
(författare)
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Understanding the gastrointestinal physiology and responses to feeding in air-breathing Anabantiform fishes
- 2020
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Ingår i: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 96:4, s. 986-1003
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Tidskriftsartikel (refereegranskat)abstract
- The Mekong Delta is host to a large number of freshwater species, including a unique group of facultative air-breathing Anabantiforms. Of these, the striped snakehead (Channa striata), the climbing perch (Anabas testudineus), the giant gourami (Osphronemus goramy) and the snakeskin gourami (Trichogaster pectoralis) are major contributors to aquaculture production in Vietnam. The gastrointestinal responses to feeding in these four species are detailed here. Relative intestinal length was lowest in the snakehead, indicating carnivory, and 5.5-fold greater in the snakeskin, indicating herbivory; climbing perch and giant gourami were intermediate, indicating omnivory. N-waste excretion (ammonia-N + urea-N) was greatest in the carnivorous snakehead and least in the herbivorous snakeskin, whereas the opposite trend was observed for net K+ excretion. Similarly, the more carnivorous species had a greater stomach acidity than the more herbivorous species. Measurements of acid-base flux to water indicated that the greatest postprandial alkaline tide occurred in the snakehead and a potential acidic tide in the snakeskin. Additional findings of interest were high levels of both PCO2 (up to 40 mmHg) and HCO3- (up to 33 mM) in the intestinal chyme of all four of these air-breathing species. Using in vitro gut sac preparations of the climbing perch, it was shown that the intestinal net absorption of fluid, Na+ and HCO3- was upregulated by feeding but not net Cl- uptake, glucose uptake or K+ secretion. Upregulated net absorption of HCO3- suggests that the high chyme (HCO3-) does not result from secretion by the intestinal epithelium. The possibility of ventilatory control of PCO2 to regulate postprandial acid-base balance in these air-breathing fish is discussed.
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