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1.
Mar Pollut Bull ; 192: 114963, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37201345

RESUMO

Marine litter is a global problem. Education has been acclaimed as a potential tool to tackle this issue, yet, integrative, student-centered, and over weeks studies to raise awareness on the theme that compares pre- with post-intervention results are limited in the literature. Furthermore, almost no studies rely on the basis of previous experience on the theme and local reality. This paper presents the design, implementation, and evaluation of an educational intervention to raise awareness and educate students (1st cycle to high-school) about marine litter. Different learning skills were fostered through theoretical, laboratorial, and hands-on activities and students participated in a beach clean-up to summarize the classroom's learnings in loco. Pre- and post-questionnaire results indicate that students' knowledge, perceptions, and behavioral intentions changed. Identification of marine litter estimated degradation times and observation of microplastics in local sand samples were activities highly appreciated by youngsters. This intervention positively impacted schoolchildren's literacy, contributing to advancing education in marine litter and can be further adapted to other educational areas.


Assuntos
Plásticos , Instituições Acadêmicas , Humanos , Criança , Estudantes , Inquéritos e Questionários , Microplásticos
2.
Plants (Basel) ; 11(10)2022 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-35631771

RESUMO

Somatic embryogenesis (SE) is a complex biological process regulated by several factors, such as the action of plant growth regulators, namely auxins, of which the most physiologically relevant is indole-3-acetic acid (IAA). In tamarillo, an optimized system for induction of SE creates, after an induction process, embryogenic (EC) and non-embryogenic callus (NEC). In this work the endogenous levels of auxin along the induction phase and in the calli samples were investigated using chemical quantifications by colorimetric reactions and HPLC as well as immunohistochemistry approaches. Differential gene expression (IAA 11, IAA 14, IAA 17, TIR 1, and AFB3) analysis during the induction phase was also carried out. The results showed that the endogenous IAA content is considerably higher in embryogenic than in non-embryogenic calli, with a tendency to increase as the dedifferentiation of the original explant (leaf segments) evolves. Furthermore, the degradation rates of IAA seem to be related to these levels, as non-embryogenic tissue presents a higher degradation rate. The immunohistochemical results support the quantifications made, with higher observable labeling on embryogenic tissue that tends to increase along the induction phase. Differential gene expression also suggests a distinct molecular response between EC and NEC.

3.
Circ Econ Sustain ; 2(2): 731-758, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34888562

RESUMO

The circular economy (CE) concept has become a major interest for companies, promising new business opportunities and a decrease in environmental impacts. Though research on circular business models has recently increased, few scholars have investigated how companies engaged with CE view the connection between CE and sustainability. To address this gap, this paper uses a semi-quantitative survey and semi-structured interviews conducted with companies based in Italy and the Netherlands. Purposive sampling was employed to target firms associated with national and international CE networks, as these companies already engage with CE practices. The survey was distributed online to over 800 firms, of which 155 provided information on their understanding of the CE concept and its relationship with sustainability. The survey results are complemented through findings from 43 interviews with a subset of the survey respondents. The survey answers show that companies view CE as one of the tools to achieve sustainable development, particularly in the environmental domain, where the focus lies on environmentally friendly resource use. Yet, the respondents are less confident whether CE increases economic and social benefits of firms. Interviews show that a majority of respondents position sustainability as the overarching concept. However, most companies advocate that the private sector should strive for both sustainability and circularity, though the distinction between the two concepts in daily business operations seems synthetic and futile to some. These findings provide an important stepping stone for better understanding how firms could apply CE practices to move towards a more sustainable society.

4.
Mar Pollut Bull ; 168: 112446, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33991982

RESUMO

Marine litter is claimed to be one of the most meaningful environmental crises of the century. Education that supports behavior change is a tool to tackle this problem. However, there is a lack of research linking educational initiatives and marine litter issues. A literature review was conducted through a bibliometric and content analysis to explore the state of knowledge regarding educational actions. The results revealed that 2019 was the year with the highest number of publications and that 83.4% of the documents were collaborative efforts. Concerning educational approaches, hands-on and technological activities are being explored to raise awareness and stimulate behavior change. Students and questionnaires represent, respectively, the most common audience and evaluating method. More integrative actions and respective long-term methodological triangulation evaluation were identified as necessary in future studies. This paper is expected to contribute to innovative knowledge in the area by identifying the main gaps in the literature.


Assuntos
Conhecimento , Estudantes , Monitoramento Ambiental , Humanos
5.
Environ Dev Sustain ; 23(8): 11257-11278, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33424430

RESUMO

The COVID-19 pandemic has caused a global crisis, one which also influences the ways sustainability is being taught at universities. This paper undertakes an analysis of the extent to which COVID-19 as a whole and the lockdown it triggered in particular, which has led to the suspension of presence-based teaching in universities worldwide and influenced teaching on matters related to sustainable development. By means of a worldwide survey involving higher education institutions across all continents, the study has identified a number of patterns, trends and problems. The results from the study show that the epidemic has significantly affected teaching practices. The lockdowns have led to a surge in the use of on-line communication tools as a partial replacement to normal lessons. In addition, many faculty teaching sustainability in higher education have strong competencies in digital literacy. The sampled higher education educations have-as a whole-adequate infrastructure to continue to teach during the lockdowns. Finally, the majority of the sample revealed that they miss the interactions via direct face-to-face student engagement, which is deemed as necessary for the effective teaching of sustainability content. The implications of this paper are two-fold. Firstly, it describes how sustainability teaching on sustainable development has been affected by the lockdown. Secondly, it describes some of the solutions deployed to overcome the problem. Finally, the paper outlines the fact that the COVID-19 pandemic may serve the purpose of showing how university teaching on sustainability may be improved in the future, taking more advantage of modern information technologies.

6.
Sci Total Environ ; 601-602: 1753-1761, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-28618664

RESUMO

This study's aim was to develop and implement an integrative epidemiologic cross-sectional study that allows identifying and characterising exposure pathways of populations living and working on the shores of a contaminated estuarine environment. Population residing in Carrasqueira, located on the Sado estuary with known contaminated areas was compared to another population on a noncontaminated estuary (Vila Nova de Mil Fontes - VNMF), considered a nonexposed population. Simple random samples of individuals were selected in each study population from the National Health Service Lists: 140 individuals were selected in Carrasqueira and 219 in VNMF. Participation rates were higher in the exposed group (62.5%, n=102 in Carrasqueira and 48.3%, n=100 individuals in VNMF). The same structured questionnaire was used in both populations, including questions on occupational activities, leisure activities, consumption of food (including fish and mollusks from the estuary) and use of water for human intake and agriculture. Results showed that a significantly higher proportion of Carrasqueira participants reported doing tasks in their job that promote direct (48.8% vs 1.2% in VNMF, p-value<0.001) or indirect (30% vs 11.9% in VNMF, p-value=0.004) contact with water from the estuary. Regarding seafood consumption, the exposed population of Carrasqueira had a higher frequency of consumption of cuttlefish (23.5% vs 9% in VNMF, p-value=0.007), sole (22.5% vs 4% in VNMF, p-value<0.001) and clams (18.6% vs 5.0 in VNMF, p-value=0.004). The comparative study design, with exposed and nonexposed populations living on the shores of two different estuaries allowed us to confirm the hypothesis of a higher risk of contamination from the contaminated estuarine environment. The study design and the selection of both populations were adequate for this type of epidemiologic study of potential routes of human contamination in a mixture of contaminated estuarine environment and can be used in other estuarine areas with similar environmental risk.


Assuntos
Exposição Ambiental/análise , Monitoramento Ambiental , Estuários , Poluentes Químicos da Água/análise , Animais , Estudos Transversais , Exposição Dietética , Estudos Epidemiológicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Exposição Ocupacional , Portugal , Alimentos Marinhos
7.
J Toxicol Environ Health A ; 78(9): 559-70, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25965191

RESUMO

Estuaries may be reservoirs of a wide variety of pollutants, including mutagenic and carcinogenic substances that may impact on the ecosystem and human health. A previous study showed that exposure of human hepatoma (HepG2) cells to extracts from sediment samples collected in two areas (urban/industrial and riverine/agricultural) of an impacted estuary (Sado, Portugal), produced differential cytotoxic and genotoxic effects. Those effects were found to be consistent with levels and nature of sediment contamination. The present study aimed at evaluating whether the mixtures of contaminants contained in those extracts were able to modulate DNA repair capacity of HepG2 cells. The residual level of DNA damage was measured by the comet assay in cells exposed for 24 or 48 h to different extracts, after a short preexposure to a challenging concentration range of ethyl methanesulfonate (EMS), as a model alkylating agent. The results suggested that the mixture of contaminants present in the tested samples, besides a potential direct effect on the DNA molecule, may also interfere with DNA repair mechanisms in HepG2 cells, thus impairing their ability to deal with genotoxic stress and, possibly, facilitating accumulation of mutations. Humans are environmentally/occupationally exposed to mixtures rather than to single chemicals. Thus, the observation that estuarine contaminants induce direct and indirect DNA strand breakage in human cells, the latter through the impairment of DNA repair, raises additional concerns regarding potential hazards from exposure and the need to further explore these endpoints in the context of environmental risk assessment.


Assuntos
Reparo do DNA/efeitos dos fármacos , Exposição Ambiental , Metanossulfonato de Etila/toxicidade , Poluentes Químicos da Água/toxicidade , Ensaio Cometa , Dano ao DNA , Estuários , Sedimentos Geológicos/análise , Células Hep G2 , Humanos , Portugal
8.
Front Genet ; 5: 437, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25540652

RESUMO

The application of the Comet assay in environmental monitoring remains challenging in face of the complexity of environmental stressors, e.g., when dealing with estuarine sediments, that hampers the drawing of cause-effect relationships. Although the in vitro Comet assay may circumvent confounding factors, its application in environmental risk assessment (ERA) still needs validation. As such, the present work aims at integrating genotoxicity and oxidative DNA damage induced by sediment-bound toxicants in HepG2 cells with oxidative stress-related effects observed in three species collected from an impacted estuary. Distinct patterns were observed in cells exposed to crude mixtures of sediment contaminants from the urban/industrial area comparatively to the ones from the rural/riverine area of the estuary, with respect to oxidative DNA damage and oxidative DNA damage. The extracts obtained with the most polar solvent and the crude extracts caused the most significant oxidative DNA damage in HepG2 cells, as measured by the formamidopyrimidine-DNA glycosylase (FPG)-modified Comet assay. This observation suggests that metals and unknown toxicants more hydrophilic than polycyclic aromatic hydrocarbons may be important causative agents, especially in samples from the rural part of the estuary, where oxidative DNA damage was the most significant. Clams, sole, and cuttlefish responded differentially to environmental agents triggering oxidative stress, albeit yielding results accordant with the oxidative DNA damage observed in HepG2 cells. Overall, the integration of in vivo biomarker responses and Comet assay data in HepG2 cells yielded a comparable pattern, indicating that the in vitro FPG-modified Comet assay may be an effective and complementary line-of-evidence in ERA even in particularly challenging, natural, scenarios such as estuarine environments.

9.
Mar Environ Res ; 99: 170-8, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24857782

RESUMO

Within an environmental risk assessment framework of a moderately contaminated estuary (the Sado, SW Portugal), the present work intended to detect endocrine disruption in a flatfish, Solea senegalensis Kaup, 1858, and its potential relationship to organic toxicants. Animals were collected from two distinct areas in the estuary (industrial and rural) and from an external reference area. Hepatic vitellogenin (VTG) levels, cytochrome P450 (CYP1A) induction, ethoxyresorufin-O-deethylase (EROD) activity plus gonad histology were analysed. Males and females were sexually immature and showed no significant evidence of degenerative pathologies. However, hepatic VTG concentrations in males from the industrial area were higher than Reference, even reaching levels comparable to females, indicating low but measurable oestrogenic effects caused by the complex contaminant mixture in estuarine sediments. These individuals also presented elevated CYP1A induction and EROD activity, which is consistent with contamination by organic toxicants such as PAHs and other aryl hydrocarbon receptor (Ahr) -mediated toxicants.


Assuntos
Disruptores Endócrinos/toxicidade , Monitoramento Ambiental/estatística & dados numéricos , Estrogênios/toxicidade , Estuários , Linguados/metabolismo , Sedimentos Geológicos/química , Xenobióticos/toxicidade , Animais , Citocromo P-450 CYP1A1/metabolismo , Disruptores Endócrinos/análise , Estrogênios/análise , Feminino , Gônadas/efeitos dos fármacos , Fígado/metabolismo , Masculino , Portugal , Estatísticas não Paramétricas , Vitelogeninas/metabolismo , Xenobióticos/análise
10.
Ecotoxicol Environ Saf ; 95: 202-11, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23810368

RESUMO

The analysis of multiple biomarker responses is nowadays recognized as a valuable tool to circumvent potential confounding factors affecting biomonitoring studies and allows a better understanding of the mechanisms underlying exposure to natural mixtures of toxicants. For the purpose of an environmental risk assessment (ERA) in an impacted estuary in SW Europe (the Sado, Portugal), juvenile Solea senegalensis from commercial fishing areas were surveyed for histopathological liver alterations and biochemical biomarkers. Although the findings revealed moderate differences in the patterns of histopathological traits between urban/industrial- and agricultural-influenced areas within the same estuary, no significant distinction was found between the cumulative alterations in animals from the two sites. The overall level of histopathological injury was low and severe traits like neoplasms or pre-neoplastic foci were absent. While metallothionein induction and lipid peroxidation could relate to histopathological condition indices, the activity of anti-oxidant enzymes appeared to be impaired in animals collected off the estuary's heavy-industry belt (the most contaminated site), which may partially explain some degree of hepatic integrity loss. Overall, the results are consistent with low-moderate contamination of the estuary and indicate that oxidative stress is the most important factor accounting for differences between sites. The study highlights the need of integrating multiple biomarkers when multiple environmental stressors are involved and the advantages of surveying toxicity effects in field-collected, foraging, organisms.


Assuntos
Monitoramento Ambiental/métodos , Linguados/anatomia & histologia , Linguados/metabolismo , Animais , Biomarcadores/análise , Ecologia , Estuários , Sedimentos Geológicos/química , Peroxidação de Lipídeos , Fígado/metabolismo , Fígado/patologia , Metalotioneína/análise , Portugal , Medição de Risco , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
11.
Environ Int ; 55: 71-91, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23528483

RESUMO

Sediment contamination remains a global problem, particularly in transitional waters such as estuaries and coastal lagoons, which are the recipients of chemicals from multiple near- and far-field sources. Although transitional waters are highly productive ecosystems, approaches for assessing and managing their sediment contamination are not as well developed as in marine and fresh waters. Further, although transitional waters remain defined by their variable and unique natural water quality characteristics, particularly salinity, the biota inhabiting such ecosystems, once thought to be defined by Remane's "paradox of brackish water", are being redefined. The purpose of the present paper is to build on an earlier but now dated (>12years old) review of methods to assess sediment contamination in estuaries, extending this to all transitional waters, including information on integrative assessments and on management decision-making. The following are specifically discussed: chemical assessments; bioindicators; biomarkers; and, biological surveys. Assessment and management of sediment contamination in transitional waters need to be focused on ecosystem services and, where appropriate and possible, be proactive rather than reactive when uncertainty has been suitably reduced.


Assuntos
Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Poluentes Químicos da Água/análise , Poluição Química da Água/prevenção & controle , Ecossistema , Estuários , Água Doce/química , Água do Mar/química
12.
Aquat Toxicol ; 126: 442-54, 2013 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-23010389

RESUMO

Bivalve histopathology is an acknowledged tool in environmental toxicology studies, however geographically restricted, limited to a few species and still lacking the degree of detail needed to develop effective (semi)quantitative approaches. A first-time detailed histopathological screening was performed on grooved carpet shell clams collected from commercial shellfish beds in distinct coastal ecosystems of the Southern Portuguese coast: two parted sites within an impacted estuary (S(1) and S(2)), an inlet channel of a fish farm at a considered pristine estuary (site M) and a site allocated in a clean coastal lagoon (A). A total of thirty histopathological lesions and alterations were analysed in the gills and digestive glands following a weighted condition indices approach, including inflammation-related responses, necrosis, neoplastic diseases and parasites. Digestive glands were consistently more damaged than gills, except for animals collected from site M, where the most severe lesions were found in both organs, immediately followed by S(2). Clams from sites S(1) and A were overall the least damaged. Neoplastic diseases were infrequent in all cases. Inflammation-related traits were some of the most common alterations progressing in animals enduring severe lesions such as digestive tubule (diverticula) and intertubular tissue necrosis. Some alterations, such as lipofuscin aggregates within digestive tubule cells, did not relate to histological lesions. Granulocytomas only occurred in heavily infected tissues. Animals from M and A presented the highest infections in the digestive gland, especially by protozoa. Gill infections were more similar between sites. Still, the level of infection does not account for all histopathological lesions in either organ. Overall, the results are in accordance with environmental parameters, such as distance to pollution sources, sediment type and hydrodynamics, and show that the combination of multiple histopathological features in these clams provides good sensitivity for inter-site distinction even when low or moderate anthropogenic impacts are at stake.


Assuntos
Bivalves/efeitos dos fármacos , Monitoramento Ambiental/métodos , Poluentes Químicos da Água/toxicidade , Animais , Bivalves/microbiologia , Bivalves/parasitologia , Trato Gastrointestinal/química , Trato Gastrointestinal/efeitos dos fármacos , Brânquias/efeitos dos fármacos , Poluentes Químicos da Água/análise
13.
Ecotoxicology ; 21(4): 1194-207, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22362511

RESUMO

Assessing toxicity of contaminated estuarine sediments poses a challenge to ecotoxicologists due to the complex geochemical nature of sediments and to the combination of multiple classes of toxicants. Juvenile Senegalese soles were exposed for 14 days in the laboratory and in situ (field) to sediments from three sites (a reference plus two contaminated) of a Portuguese estuary. Sediment characterization confirmed the combination of metals, polycyclic aromatic hydrocarbons and organochlorines in the two contaminated sediments. Changes in liver cytosolic protein regulation patterns were determined by a combination of two-dimensional electrophoresis with de novo sequencing by tandem mass spectrometry. From the forty-one cytosolic proteins found to be deregulated, nineteen were able to be identified, taking part in multiple cellular processes such as anti-oxidative defence, energy production, proteolysis and contaminant catabolism (especially oxidoreductase enzymes). Besides a clear distinction between animals exposed to the reference and contaminated sediments, differences were also observed between laboratory- and in situ-tested fish. Soles exposed in the laboratory to the contaminated sediments failed to induce, or even markedly down-regulated, many proteins, with the exception of a peroxiredoxin (an anti-oxidant enzyme) and a few others, when compared to reference fish. In situ exposure to the contaminated sediments revealed significant up-regulation of basal metabolism-related enzymes, comparatively to the reference condition. Down-regulation of basal metabolism enzymes, related to energy production and gene transcription, in fish exposed in the laboratory to the contaminated sediments, may be linked to sediment-bound contaminants and likely compromised the organisms' ability to deploy adequate responses against insult.


Assuntos
Monitoramento Ambiental/métodos , Linguados/metabolismo , Fígado/efeitos dos fármacos , Proteoma/análise , Poluentes Químicos da Água/análise , Animais , Bioensaio , Regulação para Baixo , Linguados/crescimento & desenvolvimento , Sedimentos Geológicos/química , Fígado/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Proteólise , Proteômica/métodos , Regulação para Cima
14.
Environ Pollut ; 161: 107-20, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22230075

RESUMO

Surveying toxicity of complex geochemical media as aquatic sediments often yields results that are either difficult to interpret or even contradictory to acknowledged theory. Multi-level biomarkers were investigated in a benthic fish exposed to estuarine sediments through laboratory and in situ bioassays, to evaluate their employment either in ecological risk assessment or in more mechanistic approaches to assess sediment-bound toxicity. Biomarkers reflecting lesions (such as genotoxicity or histopathology), regardless of their low or absent specificity to contaminants, are efficient in segregating exposure to contaminated from uncontaminated sediments even when classical biomarkers like CYP1A and metallothionein induction are inconclusive. Conversely, proteomics and gene transcription analyses provided information on the mechanics of toxicity and aided explaining response variation as a function of metabolic imbalance and impairment of defences against insult. In situ bioassays, although less expedite and more affected by confounding factors, produced data better correlated to overall sediment contamination.


Assuntos
Peixes/fisiologia , Sedimentos Geológicos/química , Poluentes Químicos da Água/análise , Animais , Biomarcadores/análise , Biomarcadores/metabolismo , Monitoramento Ambiental , Peixes/metabolismo , Portugal , Medição de Risco , Poluentes Químicos da Água/toxicidade
15.
Ecotoxicology ; 20(8): 1749-64, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21660599

RESUMO

The transcription of contaminant response-related genes was investigated in juvenile Senegalese soles exposed to sediments from three distinct sites (a reference plus two contaminated) of a Portuguese estuary (the Sado, W Portugal) through simultaneous 28-day laboratory and in situ bioassays. Transcription of cytochrome P450 1A (CYP1A), metallothionein 1 (MT1), glutathione peroxidase (GPx), catalase (CAT), caspase 3 (CASP3) and 90 kDa heat-shock protein alpha (HSP90AA) was surveyed in the liver by real-time PCR. CASP3 transcription analysis was complemented by surveying apoptosis through the TUNEL reaction. After 14 days of exposure, relative transcription was either reduced or decreased in fish exposed to the contaminated sediments, revealing a disturbance stress phase during which animals failed to respond to insult. After 28 days of exposure all genes' transcription responded to contamination but laboratory and in situ assays depicted distinct patterns of regulation. Although sediments revealed a combination of organic and inorganic toxicants, transcription of the CYP1A gene was consistently correlated to organic contaminants. Metallothionein regulation was found correlated to metallic and organic xenobiotic contamination in the laboratory and in situ, respectively. The transcription of oxidative stress-related genes can be a good indicator of general stress but caution is mandatory when interpreting the results since regulation may be influenced by multiple factors. As for MT1, HSP90 up-regulation has potential to be a good indicator for total contamination, as well as the CASP3 gene, even though hepatocyte apoptosis depicted values inconsistent with sediment contamination, showing that programmed cell death did not directly depend on caspase transcription alone.


Assuntos
Linguados/genética , Sedimentos Geológicos/química , Poluentes Químicos da Água/toxicidade , Animais , Apoptose/efeitos dos fármacos , Bioensaio , Caspase 3/genética , Catalase/genética , Citocromo P-450 CYP1A1/genética , Ecotoxicologia/métodos , Perfilação da Expressão Gênica , Glutationa Peroxidase/genética , Proteínas de Choque Térmico HSP90/genética , Hepatócitos/efeitos dos fármacos , Hepatócitos/patologia , Metalotioneína/genética , Portugal , Xenobióticos/toxicidade
16.
Mar Pollut Bull ; 62(1): 55-65, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20884033

RESUMO

Juvenile Senegalese soles were exposed through 28-day laboratory and field (in situ) bioassays to sediments from three sites of the Sado estuary (W Portugal): a reference and two contaminated by metallic and organic contaminants. Fish were surveyed for ten hepatic histopathological alterations divided by four distinct reaction patterns and integrated through the estimation of individual histopathological condition indices. Fish exposed to contaminated sediments sustained more damage, with especial respect to regressive changes like necrosis. However, differences were observed between laboratory- and field-exposed animals, with the latest, for instance, exhibiting more pronounced fatty degeneration and hepatocellular eosinophilic alteration. Also, some lesions in fish exposed to the reference sediment indicate that in both assays unaccounted variables produced experimental background noise, such as hyaline degeneration in laboratory-exposed fish. Still, the field assays yielded results that were found to better reflect the overall levels of contaminants and physico-chemical characteristics of the tested sediments.


Assuntos
Monitoramento Ambiental/métodos , Linguados/metabolismo , Fígado/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/metabolismo , Análise por Conglomerados , Água Doce/química , Sedimentos Geológicos/química , Fígado/metabolismo , Fígado/patologia , Metais/toxicidade , Portugal , Medição de Risco
17.
Environ Res ; 111(1): 25-36, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20965503

RESUMO

Juvenile Senegalese soles (Solea senegalensis) were exposed to estuarine sediments through 28-day laboratory and in situ (field) bioassays. The sediments, collected from three distinct sites (a reference plus two contaminated) of the Sado Estuary (W Portugal) were characterized for total organic matter, redox potential, fine fraction and for the levels of metals, polycyclic aromatic hydrocarbons (PAHs) and organochlorines, namely polychlorinated biphenyls (PCBs) and dichloro diphenyl tricholoethane plus its main metabolites (DDTs). Genotoxicity was determined in whole peripheral blood by the single-cell gel electrophoresis (SCGE or "comet") assay and by scoring erythrocytic nuclear abnormalities (ENA). Analysis was complemented with the determination of lipid peroxidation in blood plasma by the thiobarbituric acid reactive substances (TBARS) protocol and cell type sorting. The results showed that exposure to contaminated sediments induced DNA fragmentation and clastogenesis. Still, laboratory exposure to the most contaminated sediment revealed a possible antagonistic effect between metallic and organic contaminants that might have been enhanced by increased bioavailability. The laboratory assay caused a more pronounced increase in ENA whereas a very significant increase in DNA fragmentation was observed in field-tested fish exposed to the reference sediment, which is likely linked to increased lipid peroxidation that probably occurred due to impaired access to food. Influence of natural pathogens was ruled out by unaltered leukocyte counts. The statistical integration of data correlated lipid peroxidation with biological variables such as fish length and weight, whereas the genotoxicity biomarkers were more correlated to sediment contamination. It was demonstrated that laboratory and field bioassays for the risk assessment of sediment contamination may yield different genotoxicity profiles although both provided results that are in overall accordance with sediment contamination levels. While field assays may provide more ecologically relevant data, the multiple environmental variables may produce sufficient background noise to mask the true effects of contamination.


Assuntos
Linguados/sangue , Linguados/genética , Sedimentos Geológicos/química , Poluentes Químicos da Água/toxicidade , Animais , Aberrações Cromossômicas , Ensaio Cometa , Contagem de Eritrócitos , Metais Pesados/metabolismo , Metais Pesados/toxicidade , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Portugal , Análise de Componente Principal , Distribuição Aleatória , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Poluentes Químicos da Água/sangue
18.
Ecotoxicology ; 19(8): 1496-512, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20717720

RESUMO

Common cockles (Cerastoderma edule, L. 1758, Bivalvia: Cardiidae) were subjected to a laboratory assay with sediments collected from distinct sites of the Sado Estuary (Portugal). Cockles were obtained from a mariculture site of the Sado Estuary and exposed through 28-day, semi-static, assays to sediments collected from three sites of the estuary. Sediments from these sites revealed different physico-chemical properties and levels of metals and organic contaminants, ranging from unimpacted (the reference site) to moderately impacted, when compared to available sediment quality guidelines. Cockles were surveyed for bioaccumulation of trace elements (Ni, Cu, Zn, As, Cd and Pb) and organic contaminants (PAHs, PCBs and DDTs). Two sets of potential biomarkers were employed to assess toxicity: whole-body metallothionein (MT) induction and digestive gland histopathology. The bioaccumulation factor and the biota-to-soil accumulation factor were estimated as ecological indices of exposure to metals and organic compounds. From the results it is inferred that C. edule responds to sediment-bound contamination and might, therefore, be suitable for biomonitoring. The species was found capable to regulate and eliminate both types of contaminants. Still, the sediment contamination levels do not account for all the variation in bioaccumulation and MT levels, which may result from the moderate metal concentrations found in sediments, the species' intrinsic resistance to pollution and from yet unexplained xenobiotic interaction effects.


Assuntos
Cardiidae/efeitos dos fármacos , Sedimentos Geológicos/química , Compostos Orgânicos/toxicidade , Oligoelementos/toxicidade , Animais , Biomarcadores/metabolismo , Cardiidae/metabolismo , Sistema Digestório/efeitos dos fármacos , Sistema Digestório/metabolismo , Exposição Ambiental/efeitos adversos , Monitoramento Ambiental/métodos , Guias como Assunto , Metalotioneína/efeitos dos fármacos , Metalotioneína/metabolismo , Portugal , Medição de Risco/métodos , Rios , Poluentes Químicos da Água/toxicidade
19.
Ecotoxicology ; 18(8): 988-1000, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19603267

RESUMO

Juvenile Solea senegalensis were exposed to fresh sediments from three stations of the Sado estuary (Portugal) in 28-day laboratory assays. Sediments revealed distinct levels of total organic matter, fine fraction, redox potential, trace elements (arsenic, cadmium, chromium, copper, nickel, lead and zinc) and organic contaminants (polycyclic aromatic hydrocarbons, polychlorinated biphenyls and a pesticide: dichloro diphenyl trichloroethane). Organisms were surveyed for contaminant bioaccumulation and induction of two hepatic biochemical biomarkers: metallothionein (MT) and cytochrome P450 (CYP1A), as potential indicators of exposure to metallic and organic contaminants, respectively. Using an integrative approach it was established that, although bioaccumulation is in general accordance with sediment contamination, lethality and biomarker responses are not linearly dependent of the cumulative concentrations of sediment contaminants but rather of their bioavailability and synergistic effects in organisms. It is concluded that metals and organic contaminants modulate both MT and CYP1A induction and it is suggested that reactive oxygen species may be the link between responses and effects of toxicity.


Assuntos
Hidrocarboneto de Aril Hidroxilases/efeitos dos fármacos , Sedimentos Geológicos/química , Metalotioneína/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Hidrocarboneto de Aril Hidroxilases/metabolismo , Biomarcadores/metabolismo , Indução Enzimática/efeitos dos fármacos , Linguados/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Metalotioneína/metabolismo , Portugal , Espécies Reativas de Oxigênio/metabolismo , Poluentes Químicos da Água/química
20.
Ecotoxicology ; 18(8): 1165-75, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19597989

RESUMO

The purpose of this work was to integrate different methodologies to assess the potential ecological risk of estuarine sedimentary management areas, using the Sado Estuary in Portugal as case study. To evaluate the environmental risk of sediment contamination, an integrative and innovative approach was used involving assessment of sediment chemistry, sediment toxicity, benthic community structure, human driving forces and pressures and management areas organic load levels. The basis for decision-making for overall assessment was a statistical multivariate analysis appended into a score matrix tables, using a best expert judgment. The integrated approach allowed to identify from the 19 management areas analyzed, three with no risk but other three with high risk to cause adverse effects in the biota, related with the contaminants analyzed. The methodologies used showed to be effective as a support for decision making leading to future estuarine management recommendations.


Assuntos
Conservação dos Recursos Naturais , Monitoramento Ambiental/métodos , Sedimentos Geológicos/análise , Tomada de Decisões , Ecossistema , Humanos , Análise Multivariada , Portugal , Medição de Risco/métodos
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