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1.
Chemosphere ; 240: 124761, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31546190

RESUMO

The formation and control of haloacetamides (HAcAms) in drinking water have raised high attention due to their high genotoxicity and cytotoxicity, especially the most cytotoxic one, diiodoacetamide (DIAcAm). In this study, the degradation of DIAcAm by UV/chlorination was investigated in terms of degradation kinetics, efficiency, influencing factors, oxidation products and toxicity evaluation. Results revealed that the degradation of DIAcAm by UV/chlorine process followed pseudo-first-order kinetics, and the rate constant between DIAcAm and OH radicals was determined as 2.8 × 109 M-1 s-1. The contribution of Cl to DIAcAm degradation by UV/chlorine oxidation was negligible. Increasing chlorine dosage and decreasing pH significantly promoted the DIAcAm degradation during UV/chlorine oxidation, but the presence of bicarbonate (HCO3-) and natural organic matter (NOM) inhibited it. The mass balance analysis of iodine species was also evaluated during UV/chlorine oxidation of DIAcAm. In this process, with DIAcAm decreasing from 16.0 to 0.8 µM-I in 20 min, IO3-, I- and HOI/I2 increased from 0 to 6.3, 6.1 and 0.5 µM-I, respectively. The increase of CHO cell viability during DIAcAm degradation indicated that the toxicity of DIAcAm could be decreased by chlorination, UV irradiation and UV/chlorine oxidation treatments, in which UV/chlorine oxidation was more effective on toxicity reduction than chlorination and UV irradiation alone.


Assuntos
Acetamidas/química , Poluentes Químicos da Água/química , Cloro/análise , Halogenação , Cinética , Oxirredução , Raios Ultravioleta , Água , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade , Purificação da Água/métodos
2.
Chemosphere ; 238: 124589, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31437630

RESUMO

Vitellogenin (VTG), a well-established biomarker for the diagnosis of endocrine activity in fish, is used in multiple OECD test guidelines (TG) to identify activities of chemicals on hormonal pathways. However, the synthesis of VTG may not only be modified by typical endocrine-related pathways, but also through non-endocrine-mediated processes. In particular, hepatotoxicity, i.e. toxicant-induced impairment of liver structure and function, might influence VTG as a biomarker, since VTG is synthesized in hepatocytes. An intimate understanding of the interplay between endocrine-related and non-endocrine-related pathways influencing VTG production is crucial for the avoidance of erroneous diagnoses in hazard assessment for regulatory purposes of chemical compounds. In order to investigate whether hepatotoxicity may interfere with hepatic VTG synthesis, adult zebrafish (Danio rerio) were exposed to three well-known hepatotoxicants, acetaminophen, isoniazid and acetylsalicylic acid, according to OECD TG 230. Various hepatotoxicity- and endocrine system-related endpoints were recorded: mRNA expression of selected endocrine- and hepatotoxicity-related marker genes in the liver; VTG levels in head/tail homogenates; and liver histopathology. All three test compounds induced significant, but mild single cell necrosis of hepatocytes and transcriptional changes of hepatotoxicity-related marker genes, thus confirming hepatotoxic effects. A positive correlation between hepatotoxicity and reduced hepatic VTG synthesis was not observed, with the single exception of a weak increase in female zebrafish exposed to APAP. This suggests that - in studies conducted according to OECD TG 229 or 230 - it is unlikely that hepatotoxic chemicals will interfere with the hepatic capacity for VTG synthesis.


Assuntos
Acetaminofen/toxicidade , Aspirina/toxicidade , Hepatócitos/metabolismo , Isoniazida/toxicidade , Vitelogeninas/biossíntese , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/metabolismo , Animais , Doença Hepática Induzida por Substâncias e Drogas , Sistema Endócrino/efeitos dos fármacos , Feminino , Hepatócitos/efeitos dos fármacos , Masculino , Proteínas de Peixe-Zebra/biossíntese
3.
Chemosphere ; 238: 124592, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31442778

RESUMO

Tetrabromobisphenol A (TBBPA), a brominated flame retardant used in synthetic polymers and electronics, is present in the aquatic environment and recent evidence suggests it can be potentially biomagnified in the marine ecosystem. However, the toxicity of TBBPA in the marine biota has not been investigated in detail. In this study we aimed to understand the role of carboxylesterases (CEs) in xenobiotic metabolism under the exposure of marine organisms to a chemical of environmental concern, TBBPA. Specifically, we tested for in vitro inhibition of CE activity in a range of marine organisms covering different ecological niches, from species from low (mussels and copepods), medium (sardines and anchovies) and high trophic levels (tuna). The results revealed that the highest inhibition of CE activity to 100 µM TBBPA was recorded in mussels (66.5% inhibition) and tunids (36.3-76.4%), whereas copepods and small pelagic fish showed comparatively lower effects (respectively, 30% and 36.5-55.6%). Our results suggest that CE-mediated detoxification and physiological processes could be compromised in TBBPA-exposed organisms and could ultimately affect humans as many of them are market species.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Hidrolases de Éster Carboxílico/antagonistas & inibidores , Retardadores de Chama/toxicidade , Bifenil Polibromatos/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Ecossistema , Peixes/metabolismo , Halogenação , Humanos , Alimentos Marinhos
4.
Chemosphere ; 238: 124563, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31454744

RESUMO

Nanoplastic pollution is widespread and persistent across global water systems and can cause a negative effect on aquatic organisms, especially the zooplankter which is the keystone of the food chain. The present study uses RNA sequencing to assess the global change in gene expression caused by 21 days of exposure to 75 nm polystyrene (PS) nanoplastics on Daphnia pulex, a model organism for ecotoxicity. With the threshold value at P value < 0.05 and fold change >2, 244 differentially expressed genes were obtained. Combined with real-time PCR validation of several selected genes, our results indicated that a distinct expression profile of key genes, including downregulated trehalose transporter, trehalose 6-phosphate synthase/phosphatase, chitinase and cathepsin-L as well as upregulated doublesex 1 and doublesex and mab-3 related transcription factor-like protein, contributed to the toxic effects of chronic nanoplastic exposure on Daphnia, such as slowed growth, subdued reproductive ability and reproductive pattern shifting. Our study also showed that chronic exposure to nanoplastic changed the sex ratio of D. pulex neonates. By integrating the gene expression pattern in an important model organism, this study gained insight into the molecular mechanisms of the toxic effect of chronic PS nanoplastic exposure on D. pulex, which may also extend to other nanoplastics or aquatic animals.


Assuntos
Daphnia/efeitos dos fármacos , Poliestirenos/toxicidade , Reprodução/efeitos dos fármacos , Razão de Masculinidade , Poluentes Químicos da Água/toxicidade , Animais , Organismos Aquáticos/efeitos dos fármacos , Daphnia/genética , Cadeia Alimentar , Expressão Gênica/efeitos dos fármacos , Humanos , Recém-Nascido , Análise de Sequência de RNA
5.
Chemosphere ; 238: 124584, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31470313

RESUMO

Exposure to endocrine disrupting chemicals has been suggested to contribute to the ongoing globally increasing obesity trend. The complex chemical mixtures that humans and wildlife are exposed to include a number of compounds that may have obesogenic properties. In this study we examined a mixture consisting of phthalate-monoesters, triclosan, and perfluorinated compounds. The mixture was designed within the EDC-MixRisk project based on serum levels of the compounds in pregnant women of a Swedish mother-child cohort. The compounds were negatively associated with birth weight of the children. We assessed whether developmental exposure to this mixture in combination with a calorie-rich diet affected metabolic rate, blood lipids, adipogenesis and lipid storage, and the whole-body level of neutral lipids in zebrafish (Danio rerio). Wildtype zebrafish were exposed to the mixture from 3 h post fertilization to 5, 14 or 17 days post fertilization (dpf) at water concentrations corresponding to 1, 10, 20, or 100 times the geometrical mean of the serum concentration (hsc) in the women. Exposure to the mixture at 20 times hsc lowered metabolic rate at 2-5 dpf, and increased the number of adipocytes and the amount of visceral adipose tissue at 14 and 17 dpf respectively. Also, mRNA expression of fatty acid binding protein 11a was increased at 17 dpf by 10 and 20 times hsc of the mixture. This study shows that a human-relevant mixture of environmental pollutants affects metabolic rate, adipogenesis and lipid storage in young zebrafish fed a calorie-rich diet, thus demonstrating its potential to disrupt metabolism.


Assuntos
Adipogenia/efeitos dos fármacos , Metabolismo Basal/efeitos dos fármacos , Disruptores Endócrinos/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/metabolismo , Animais , Peso ao Nascer/efeitos dos fármacos , Proteínas de Ligação a Ácido Graxo/biossíntese , Proteínas de Ligação a Ácido Graxo/genética , Feminino , Humanos , Hidrocarbonetos Fluorados/toxicidade , Ácidos Ftálicos/toxicidade , Gravidez , Triclosan/toxicidade , Proteínas de Peixe-Zebra/biossíntese , Proteínas de Peixe-Zebra/genética
6.
Chemosphere ; 238: 124588, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31545210

RESUMO

Few works have addressed the effects provoked by the exposure to cadmium containing nanoparticles (NPs) on adult zebrafish (Danio rerio). We studied the effects of CdS NPs (5 nm) or ionic cadmium (10 µg Cd/L) after 3 and 21 d of exposure and at 6 months post-exposure (mpe). Acute toxicity was recorded after exposure to both forms of cadmium. Significant cadmium accumulation was measured in the whole fish after both treatments and autometallography showed a higher accumulation of metal in the intestine than that in the liver. Histopathological alterations, such as inflammation in gills and vacuolization in the liver, were detected after the exposure to both cadmium forms and, in a lower extent, at 6 mpe. X-ray analysis proved the presence of CdS NPs in these organs. The hepatic transcriptome analysis revealed that gene ontology terms such as "immune response" or "actin binding" were over-represented after 21 d of exposure to ionic cadmium respect to CdS NPs treatment. Exposure to CdS NPs caused a significant effect on pathways involved in the immune response and oxidative stress, while the exposure to ionic cadmium affected significantly pathways involved in DNA damage and repair and in the energetic metabolism. Oxidative damage to liver proteins was detected after the exposure to ionic cadmium, while a stronger destabilization of the hepatocyte lysosomal membrane was recorded under exposure to CdS NPs. In summary, although ionic cadmium provoked stronger effects than CdS NPs, both cadmium forms exerted an array of lethal and sublethal effects to zebrafish.


Assuntos
Bioacumulação/fisiologia , Compostos de Cádmio/toxicidade , Cádmio/toxicidade , Sulfetos/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/metabolismo , Animais , Dano ao DNA/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Brânquias/metabolismo , Nanopartículas Metálicas/toxicidade , Estresse Oxidativo/efeitos dos fármacos
7.
Chemosphere ; 238: 124753, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31545217

RESUMO

Boscalid is a widely used fungicide in agriculture and has been frequently detected in both environments and agricultural products. However, evidence on the neurotoxic effect of boscalid is scarce. In this study, zebrafish served as an animal model to investigate the toxic effects and mechanisms of boscalid on aquatic vertebrates or higher animals. And we unravelled that boscalid induced developmental defects associated with oxidative stress. Developmental defects, including head deformity, hypopigmentation, decreased number of newborn neurons, structural defects around the ventricle, enlarged intercellular space in the brain, and nuclear concentration, were observed in zebrafish embryos after boscalid exposure at 48 hpf. Interestingly, we found that boscalid might directly induce oxidative stress and alter the activity of ATPase, which in turn disrupted the expression of genes involved in neurodevelopment and transmitter-transmitting signalings and melanocyte differentiation and melanin synthesis signalings. Ultimately, the differentiation of nerve cells and melanocytes were both impacted and the synthesis of melanin was inhibited, leading to morphological abnormalities. Additionally, exposure to boscalid led to less and imbalance motion and altered tendency of locomotor in larval fish. Collectively, our results provide new evidences for a comprehensive assessment of its toxicity and a warning for its residues in environment and agricultural products.


Assuntos
Compostos de Bifenilo/toxicidade , Fungicidas Industriais/toxicidade , Larva/efeitos dos fármacos , Niacinamida/análogos & derivados , Estresse Oxidativo/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/embriologia , Animais , Diferenciação Celular/efeitos dos fármacos , Modelos Animais de Doenças , Embrião não Mamífero/efeitos dos fármacos , Humanos , Melaninas/biossíntese , Melanócitos/citologia , Neurônios/citologia , Síndromes Neurotóxicas/patologia , Niacinamida/toxicidade , Peixe-Zebra/metabolismo
8.
Sci Total Environ ; 700: 134400, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31689654

RESUMO

Daphnids are freshwater crustaceans used in toxicity tests. Although lethality and immobilisation are the most commonly used endpoints in those tests, more sensitive parameters are required for determination of sublethal acute effects of toxicants. The use of various physiological endpoints in daphnids is considered as a low-cost and simple alternative that meets the 3R's rule (Replacement, Reduction, Refinement) criteria. However, currently there is no review-based evaluation of their applicability in toxicity testing. This paper presents the results on the most commonly determined physiological parameters of Daphnia in ecotoxicological studies and human drug testing, such as feeding activity, thoracic limb movement, heart rate, cardiac area, respiratory activity, compound eye, mandible movements and post-abdominal claw contractions. Furthermore, their applicability as promising endpoints in the assessment of water quality or drug testing is discussed.


Assuntos
Daphnia/fisiologia , Testes de Toxicidade Aguda/métodos , Poluentes Químicos da Água/toxicidade , Animais , Ecotoxicologia
9.
Chemosphere ; 239: 124672, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31494319

RESUMO

Environmental factors such as temperature and light are the most determinants in the photosynthetic productivity in microalgae. However, under extreme of these conditions, certain resistant microalgae strains possess additional abilities such as growth in the presence of high concentrations of metals and some can improve in combinations of more than one abiotic stress. Therefore, the aim of this research was to evaluate the efficiency in photosynthetic production through the oxygen balance to variations in photon intensity, and under temperature changes in a Cd-resistant strain (DcRCd100) compared to the wild-type strain (Dc1Mwt) of Dictyosphaerium chlorelloides. The results showed that the DcRCd100 strain has the maximum efficiency at 200  µmol m-2 s-1 on photosynthesis net (Pn) (96.32 ±â€¯3.63% nmol O2 ml-1 min-1) as the threshold light saturation, and an adaptation to maintain this maximum photosynthetic gross (Pg) rate at 30 °C (94.99 ±â€¯10.03% nmol O2 ml-1 min-1) due to possible modifications in the photosynthetic apparatus that is reflected in the net evolution rate of O2 to deal with such evaluated conditions. While, Dc1Mwt strain its maximum photosynthetic efficiency was at 300 µmol m-2 s-1 and 21 °C (97.72 ±â€¯2.99 and 99.85 ±â€¯0.30%nmol O2 ml-1 min-1, respectively) and in optimal response to the oxygen balance that is normally achieved by this mesophilic genus. These results provide a new prediction of mechanisms in the oxygen evolution in photosynthesis that rules the correlation between resistance and adaptation to extreme abiotic conditions in metal resistant strains of eukaryotic microalgae.


Assuntos
Cádmio/toxicidade , Chlorella/efeitos dos fármacos , Microalgas/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Adaptação Fisiológica/fisiologia , Chlorella/crescimento & desenvolvimento , Microalgas/crescimento & desenvolvimento , Oxigênio/metabolismo , Taxa Respiratória
10.
Chemosphere ; 239: 124668, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31494325

RESUMO

Nitrite is one of major environmental pollutants that can impact immunological parameters in aquatic organisms. In the present study, we investigated the effects of nitrite exposure on oxidative stress, DNA damage and apoptosis in mud crab (Scylla paramamosain). Mud crab were exposed to 0, 5, 10 and 15 mg L-1 nitrite for 72 h. These data showed that acid phosphatase (ACP) and alkaline phosphatase (ALP) activity significantly decreased in treatments with various concentrations of nitrite (5, 10 and 15 mg L-1) after 24 and 48 h, while the levels of nitric oxide (NO) significantly increased in these treatments. Nitrite exposure could suppress superoxide dismutase (SOD) and catalase (CAT) activity, and increase the formation of malondialdehyde (MDA) after 48 and 72 h of exposure. In addition, nitrite exposure decreased total haemocyte counts after 48 and 72 h of exposure. Cytological damage, DNA damage and apoptosis was observed obviously at 72 h after nitrite exposure. Moreover, nitrite exposure significantly induced the mRNA levels of phosphorylated Jun N-terminal kinases (JNK), and eventually activated p53 signaling and caspase-3. These results indicated that nitrite exposure could induce oxidative stress, which further caused DNA damage and apoptosis in mud crab. Our results will be helpful to understand the mechanism of nitrite toxicity on crustaceans.


Assuntos
Apoptose/efeitos dos fármacos , Braquiúros/efeitos dos fármacos , Dano ao DNA/genética , Nitritos/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Fosfatase Ácida/metabolismo , Fosfatase Alcalina/metabolismo , Animais , Braquiúros/genética , Catalase/metabolismo , Hemócitos , Malondialdeído/metabolismo , Óxido Nítrico/metabolismo , Transdução de Sinais , Superóxido Dismutase/metabolismo
11.
Chemosphere ; 238: 124610, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31450112

RESUMO

Antifouling paint particles (APPs) are residues generated primarily during maintenance of vessels and marine structures, and usually occur in boat maintenance areas that are adjacent to aquatic environments, such as estuaries. APPs end up in sediment layers after their release into aquatic systems and represent a threat to benthic invertebrates, which have different habitat and feeding modes. Thus, the aim of the present study was to evaluate the toxicity of APPs-spiked sediment to the benthic microcrustaceans Monokalliapseudes schubarti (a tanaid) and Hyalella azteca (an amphipod), testing whole sediment and elutriate solutions under estuarine conditions. Whole sediment spiked with APPs was more toxic to these organisms than the elutriate solution. This toxicity was attributed to the high concentrations of Cu and Zn metals quantified in the APPs. During the whole sediment test, M. schubarti was more sensitive than H. azteca. M. schubarti is an infauna organism, and its interaction with sediments (e.g. by ingestion of sediment particles) makes it more susceptible to compounds released from APPs than H. azteca, which tends to interact with these compounds at the sediment-water interface. In addition, in tests with sediment elutriate and without sediment, M. schubarti was not affected, while elutriate with 1.50% APPs showed to be significantly toxic to H. azteca. Moreover, these results indicate that APPs act as continuous and localized sources of metals to benthic organisms, highlighting the importance of better APP management and disposal practices in boat maintenance areas to avoid local aquatic contamination.


Assuntos
Anfípodes/efeitos dos fármacos , Crustáceos/efeitos dos fármacos , Sedimentos Geológicos/análise , Pintura/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Incrustação Biológica/prevenção & controle
12.
Chemosphere ; 238: 124616, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31466003

RESUMO

The Alagados Reservoir (Southern Brazil) is used as water supply, and since 2002 there have been reports with a presence of cyanobacterial blooms and cyanotoxins. In order to assess the water quality and the ecological integrity of the reservoir, we evaluated biochemical, genotoxic and osmoregulatory biomarkers in the freshwater cichlid fish (Geophagus brasiliensis) that were exposed to PSTs. The fish were sampled in the Alagados Reservoir in February 2016 (Summer) and were divided in three groups: 1) Reservoir group (RES): fish were collected immediately after sampling; 2) Depuration group (DEP): fish were submitted to the depuration experiment for 90 days in the laboratory; and 3) Reproduction group (REP): fish were kept in the laboratory until the fertilization and the chemical analyses were performed on the offspring (F1 generation). In the RES and DEP the blood, brain, muscle, liver and gills were collected for biochemical, genotoxic and osmoregulatory biomarkers analysis. Our results showed that the fish from the Alagados Reservoir (RES) presented oxidative stress and DNA damage; and after 90 days (DEP), the antioxidant system and DNA damage were recovered. Although PSTs were considered a risk to the ecological integrity of this water body; PSTs concentrations were not found in the tissues of the F1 generation. In addition, the biomarkers used were useful tools to evaluate the effects of environment contamination. Therefore, it is necessary to develop new technologies and monitoring programs in order to reduce cyanobaterial blooms, cyanotoxins and human activities that cause the contamination in aquatic environments.


Assuntos
Biomarcadores/análise , Ciclídeos/metabolismo , Dano ao DNA/efeitos dos fármacos , Alimentos Marinhos/análise , Toxinas Biológicas/análise , Poluentes Químicos da Água/análise , Animais , Ciclídeos/crescimento & desenvolvimento , Monitoramento Ambiental , Humanos , Toxinas Biológicas/toxicidade , Poluentes Químicos da Água/toxicidade
13.
Chemosphere ; 239: 124752, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31514010

RESUMO

The online biomonitoring of aquatic accidental pollution is very important to realize the assessment of complex toxicity. However, the monitoring results would be affected greatly by the internal physio-ecological changes of test organisms, and circadian rhythms might contribute greatly to this kind of effects. In the present study, the behavior responses of zebrafish (Danio rerio) to different concentrations of Deltamethrin, Atrazine, and Thallium (Tl) in 15 days were investigated using an online behavior monitoring system. The results showed that the average behavior strength (BS) value of dark period (0.71 ±â€¯0.16) was lower than that of light period (0.88 ±â€¯0.09) in the control group. Similar pattern was observed in all other treatments with negative relationship between exposure concentrations and mean BS values. It is concluded that the 24 h circadian rhythms in the behavior responses of zebrafish (Danio rerio) could be observed clearly in the online biomonitoring system, and the online monitoring results would be affected obviously in the characteristics of behavior periodicity abnormal and time delay. Therefore, it is suggested that internal physio-ecological characteristics of organisms must be considered once they have the chance to play roles in bio-induced technologies. More investigations are warranted to clear the effects of internal physio-ecological changes on the exported results.


Assuntos
Comportamento Animal/efeitos dos fármacos , Ritmo Circadiano/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Qualidade da Água , Peixe-Zebra/fisiologia , Animais , Atrazina/toxicidade , Nitrilos/toxicidade , Piretrinas/toxicidade , Tálio/toxicidade
14.
Chemosphere ; 239: 124751, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31518922

RESUMO

Bisphenol A (BPA) is a chemical monomer widely used in the production of hard plastics for food containers and personal items. Through improper industrial control and disposal, BPA has become a pervasive environmental contaminant, and toxicological studies have shown potent xenobiotic endocrine disruptor activity. Prenatal exposure in particular can lead to infertility and nervous system disorders characterized by behavioral aggression, depression, and cognitive impairment, thus necessitating careful hazard assessment. In this study, we evaluated BPA accumulation rate, blood-brain barrier (BBB) permeability, lethality, cardiotoxicity, behavioral effects, and impacts on multiple neurochemical pathways in zebrafish larvae. The bioconcentration factor (BCF) ranged from 1.95 to 10.0, resulting in a high rate of accumulation in the larval body. Also, high BBB permeability allowed BPA to accumulate at similar rates in both zebrafish and adult mouse (blood to brain concentration ratios of 3.2-6.7 and 1.8 to 5.5, respectively). In addition, BPA-exposed zebrafish larvae exhibited developmental deformities, reduced heart rate, and impaired behavioral patterns, including decreased total distance traveled, slower movement velocity, and altered color-preference. These impairments were associated with inhibition of the phenylalanine to dopamine synthesis pathway and an imbalance between excitatory and inhibitory neurotransmitter systems. Our results suggest that behavioral alteration in BPA-exposed zebrafish result from high accumulation and ensuing dysregulation of serotonergic, kynurenergic, dopaminergic, cholinergic, and GABAergic neurotransmitter systems. In conclusion, similarities in toxic responses to mammalian models highlight the utility of the zebrafish larva as a convenient model for screening environmental toxins.


Assuntos
Comportamento Animal/efeitos dos fármacos , Compostos Benzidrílicos/toxicidade , Barreira Hematoencefálica/efeitos dos fármacos , Disruptores Endócrinos/toxicidade , Neurotransmissores/metabolismo , Fenóis/toxicidade , Peixe-Zebra/fisiologia , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Feminino , Larva/efeitos dos fármacos , Masculino , Camundongos Endogâmicos ICR , Testes de Toxicidade Aguda , Poluentes Químicos da Água/toxicidade
15.
Chemosphere ; 239: 124748, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31520971

RESUMO

A total of 100 samples were collected from the sediments of a typical copper mining area, south China. Leaching concentrations of selected heavy metals (Ni, Cd, Cu, Pb, Zn, Ba, As, and Hg) were measured to evaluate their distribution patterns and associated health risk. Leaching concentrations of Cu (3.58 ±â€¯1.49 mg/L), Pb (1.50 ±â€¯1.06 mg/L), and Zn (4.04 ±â€¯1.68 mg/L) were significantly higher than the other metals in the samples. By evaluating the spatial heterogeneity, it was found that leaching metal concentrations did not decrease with environmental gradients, mostly caused by diverse distribution in pollution sources. The hazard index and carcinogenic risk indices showed significant risks of human exposure. For public safety, priority governance should be given to the main pollutants (Cd, Cu, Pb, Zn, and As) in sediments. In future studies, the integrated data will be urgently required for local stakeholders to conduct environmental monitoring and remediation scenarios.


Assuntos
Sedimentos Geológicos/análise , Metais Pesados/análise , Mineração , Poluentes do Solo/análise , Poluentes Químicos da Água/toxicidade , Carcinógenos/toxicidade , China , Cobre , Exposição Ambiental/efeitos adversos , Monitoramento Ambiental , Humanos , Metais Pesados/toxicidade , Modelos Teóricos , Saúde Pública , Medição de Risco , Poluentes do Solo/toxicidade , Poluentes Químicos da Água/análise
16.
Chemosphere ; 240: 124936, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31568941

RESUMO

Triphenyltin (TPT) is widely used and commonly found in a water environment, so its effects on aquatic systems are of great concern. This study aimed to reveal the effects of chronic parental exposure of TPT on thyroid disruption and growth inhibition in zebrafish. Adult zebrafish (F0 generation) were exposed to environmentally relevant concentrations (1, 10, and 100 ng/L) of TPT for 60 days, and the larvae (F1 generation) were tested without TPT treatment. Results demonstrated that parental exposure to TPT disrupts thyroid function in zebrafish offspring: serum thyroxine (T4) significantly decreased, while serum 3,5,3'-triiodothyronine (T3) increased, and several genes involved in the hypothalamic-pituitary-thyroid (HPT) axis were down-regulated. In addition, we observed developmental abnormalities in the larvae, demonstrated by a significantly altered hatching rate, malformation rate, body length, heart rate, and survival rate, as well as down-regulation of genes involved in the growth hormone/insulin-like growth factor (GH/IGF) axis. Therefore, parental exposure to TPT induces toxicity in fish offspring through perturbation of the HPT and GH/IGF axes.


Assuntos
Larva/crescimento & desenvolvimento , Compostos Orgânicos de Estanho/toxicidade , Praguicidas/toxicidade , Glândula Tireoide/patologia , Poluentes Químicos da Água/toxicidade , Animais , Feminino , Hormônio do Crescimento/genética , Hormônio do Crescimento/metabolismo , Larva/efeitos dos fármacos , Masculino , Exposição Materna/efeitos adversos , Exposição Paterna/efeitos adversos , Somatomedinas/genética , Somatomedinas/metabolismo , Glândula Tireoide/efeitos dos fármacos , Tiroxina/sangue , Tri-Iodotironina/sangue , Peixe-Zebra/embriologia
17.
Chemosphere ; 240: 124942, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31574434

RESUMO

Advanced oxidation processes (AOPs) can degrade heavy metal complexes in wastewater to improve the removal efficiency of metals. However, the influences of AOP treatments on toxicity induced by metal complexes are not well understood. This study compared the toxicity induced by EDTA-copper (Cu) after UV/persulfate (PS) and UV/H2O2 treatments on luminescent bacteria and human HepG2 cells. The results showed that EDTA-Cu complexes decreased Cu toxicity in luminescent bacteria but increased the cytotoxicity in HepG2 cells, indicating species-specific toxicity. The UV/PS and UV/H2O2 treatments under most pH values and [oxidant]/[EDTA-Cu] conditions decreased the toxicity of EDTA-Cu in HepG2 cells but increased the toxicity in luminescent bacteria. When the ratio of [oxidant] to [EDTA-Cu] was 10, low toxicity in treated solutions was observed in both UV treatment processes. The alkaline precipitation treatment had a significant influence on toxicity reduction after UV/PS treatment; however, it had minimal influence on the UV/H2O2 treatment system. The Cu and total organic carbon (TOC) removal efficiency cannot completely explain the results of toxicity assays. EDTA-Cu intermediates might play important roles in changing the toxicity of EDTA-Cu after both UV treatments. This study provides insights into evaluating the treatment efficiency of UV/PS and UV/H2O2 on EDTA-Cu decomplexation.


Assuntos
Complexos de Coordenação/toxicidade , Cobre/toxicidade , Ácido Edético/toxicidade , Peróxido de Hidrogênio/química , Photobacterium/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Transportadores de Cassetes de Ligação de ATP/metabolismo , Linhagem Celular Tumoral , Ácido Edético/química , Células Hep G2 , Humanos , Oxirredução , Raios Ultravioleta , Águas Residuárias/química
18.
Sci Total Environ ; 698: 134155, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31505347

RESUMO

Despite being considered environmentally safe, a deeper environmental risk assessment is needed for microbial insecticides; special attention should be devoted to their sublethal toxicity to non-target species. This study evaluated effects of VectoBac® 12AS - VB (based on the bacterium Bacillus thurigiensis var. israelensis) and Naturalis®-L - NL (based on the fungus Beauveria bassiana) on the aquatic insect Chironomus riparius life-history and biochemical responses. Acute tests estimated a 48 h-LC50 (median lethal concentration) of 1.85 µg/L (VB) and 34.7 mg/L (NL). Under sublethal exposure, VB decreased adults' emergence (LOEC - lowest observed effect concentration of 80 ng/L) while NL impaired larval growth (LOEC of 0.32 mg/L) and delayed emergence (LOEC of 2 mg/L for males and 0.8 mg/L for females). Despite not being monotonic, phenoloxidase activity increased (LOEC of 20 ng/L (VB) and 2 mg/L (NL)), suggesting activation of the immune system. There were no indications of oxidative damage nor neurotoxicity. Catalase activity was stimulated with all VB treatments, possibly associated with detoxification of immune response products. Under NL exposure, glutathione-S-transferase activity increased but did not show a dose-dependent response and, total glutathione decreased in the highest concentration. Exposure to both formulations caused the increase in protein content, while carbohydrate and lipids were not altered. This study revealed the susceptibility of C. riparius to VB and NL at concentrations below the ones recommended for field application, with potential population-level effects. These results add important information for the risk assessment of these microbial insecticides in aquatic ecosystems, considering relevant sublethal endpoints and raising concern about the adverse effects on non-target aquatic organisms.


Assuntos
Chironomidae/fisiologia , Inseticidas/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Bacillus thuringiensis , Beauveria , Feminino , Masculino
19.
Sci Total Environ ; 698: 134133, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31505348

RESUMO

The series of breakthroughs that have occurred within the realm of nanotechnology have been the source of several new products and technological interventions. One of the most salient examples in this regard is the widespread employment of titanium dioxide (TiO2) nanoparticles across a range of consumer goods. Given that waste is generated at every stage of the consumer-product cycle (from production to disposal), many items with TiO2 nanoparticles are likely to end up being discarded into water bodies. In order to understand the interaction of TiO2 NPs with aquatic ecosystem, the ecological fate and toxicity of TiO2 NPs was studied by exposing zebrafish embryos to a combination of abiotic factors (humic acid and clay) to assess its effect on the development of zebrafish embryos. The physiological changes were correlated with genetic marker analysis to holistically understand the effect on embryos development. Derjaguin-Landau-Verwey-Overbeek (DLVO) theory was used to analyze the interaction energy between TiO2 NPs and natural organic matter (NOM) for understanding the aggregation behavior of engineered nanoparticles (ENPs) in media. The study revealed that combination of HA and clay stabilized TiO2 NPs, compared to bare TiO2 and HA or clay alone. TiO2 NPs and TiO2 NPs + Clay significantly altered the expression of genes involved in development of dorsoventral axis and neural network of zebrafish embryos. However, the presence of HA and HA + clay showed protective effect on zebrafish embryo development. The complete system analysis demonstrated the possible ameliorating effects of abiotic factors on the ecotoxicity of ENPs.


Assuntos
Argila/química , Nanopartículas Metálicas/toxicidade , Titânio/toxicidade , Animais , Embrião não Mamífero , Desenvolvimento Embrionário/efeitos dos fármacos , Substâncias Húmicas/análise , Nanopartículas Metálicas/química , Titânio/química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/toxicidade , Peixe-Zebra
20.
Chemosphere ; 238: 124604, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31450113

RESUMO

Accurate in silico predictions of chemical substance ecotoxicity has become an important issue in recent years. Most conventional methods, such as the Ecological Structure-Activity Relationship (ECOSAR) model, cluster chemical substances empirically based on structural information and then predict toxicity by employing a log P linear regression model. Due to empirical classification, the prediction accuracy does not improve even if new ecotoxicity test data are added. In addition, most of the conventional methods are not appropriate for predicting the ecotoxicity on inorganic and/or ionized compounds. Furthermore, a user faces difficulty in handling multiple Quantitative Structure-Activity Relationship (QSAR) formulas with one chemical substance. To overcome the flaws of the conventional methods, in this study a new method was developed that applied unsupervised machine learning and graph theory to predict acute ecotoxicity. The proposed machine learning technique is based on the large AIST-MeRAM ecotoxicity test dataset, a software program developed by the National Institute of Advanced Industry Science and Technology for Multi-purpose Ecological Risk Assessment and Management, and the Molecular ACCess System (MACCS) keys that vectorize a chemical structure to 166-bit binary information. The acute toxicity of fish, daphnids, and algae can be predicted with good accuracy, without requiring log P and linear regression models in existing methods. Results from the new method were cross-validated and compared with ECOSAR predictions and show that the new method provides better accuracy for a wider range of chemical substances, including inorganic and ionized compounds.


Assuntos
Ecotoxicologia/métodos , Aprendizado de Máquina , Poluentes Químicos da Água/toxicidade , Poluição Química da Água/análise , Animais , Simulação por Computador , Daphnia/efeitos dos fármacos , Peixes , Modelos Lineares , Modelos Teóricos , Relação Quantitativa Estrutura-Atividade , Medição de Risco/métodos , Software , Poluentes Químicos da Água/química
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