Publications by authors named "Sandra Caeiro"

21 Publications

  • Page 1 of 1

Marine litter: A review of educative interventions.

Mar Pollut Bull 2021 Jul 12;168:112446. Epub 2021 May 12.

Department of Science and Technology, Portuguese Distance Learning University, Lisbon, Portugal; CENSE - Center for Environmental and Sustainability Research, School of Science and Technology, NOVA University of Lisbon, Lisbon, Portugal.

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.
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http://dx.doi.org/10.1016/j.marpolbul.2021.112446DOI Listing
July 2021

COVID-19: the impact of a global crisis on sustainable development teaching.

Environ Dev Sustain 2021 Jan 6:1-22. Epub 2021 Jan 6.

School of Humanities and Social Sciences, Sustainability Literacy Institute, College of Charleston, Charleston, USA.

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.
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http://dx.doi.org/10.1007/s10668-020-01107-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7785399PMC
January 2021

An epidemiological approach to characterise the human exposure pathways in a contaminated estuarine environment.

Sci Total Environ 2017 Dec 11;601-602:1753-1761. Epub 2017 Jun 11.

Epidemiology Department, Instituto Nacional de Saúde Doutor Ricardo Jorge, Avenida Padre Cruz, 1649-016 Lisboa, Portugal; Centro de investigação em Saúde Pública, Escola Nacional de Saúde Pública, Universidade Nova de Lisboa, Portugal.

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.
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http://dx.doi.org/10.1016/j.scitotenv.2017.05.108DOI Listing
December 2017

Exploring the potential interference of estuarine sediment contaminants with the DNA repair capacity of human hepatoma cells.

J Toxicol Environ Health A 2015 ;78(9):559-70

a National Institute of Health Dr. Ricardo Jorge, I.P. , Department of Human Genetics , Lisbon , Portugal.

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.
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http://dx.doi.org/10.1080/15287394.2015.1006712DOI Listing
July 2015

An integrative assessment to determine the genotoxic hazard of estuarine sediments: combining cell and whole-organism responses.

Front Genet 2014 10;5:437. Epub 2014 Dec 10.

Departamento de Genética Humana, Instituto Nacional de Saúde Dr.Ricardo Jorge Lisboa, Portugal.

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.
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http://dx.doi.org/10.3389/fgene.2014.00437DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4261831PMC
December 2014

May sediment contamination be xenoestrogenic to benthic fish? A case study with Solea senegalensis.

Mar Environ Res 2014 Aug 9;99:170-8. Epub 2014 May 9.

IMAR - Instituto do Mar, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, 2829-516 Caparica, Portugal. Electronic address:

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.
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http://dx.doi.org/10.1016/j.marenvres.2014.04.012DOI Listing
August 2014

Ecological risk assessment of impacted estuarine areas: integrating histological and biochemical endpoints in wild Senegalese sole.

Ecotoxicol Environ Saf 2013 Sep 28;95:202-11. Epub 2013 Jun 28.

IMAR, Instituto do Mar, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, Caparica, Portugal.

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.
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http://dx.doi.org/10.1016/j.ecoenv.2013.06.004DOI Listing
September 2013

Assessing and managing sediment contamination in transitional waters.

Environ Int 2013 May 22;55:71-91. Epub 2013 Mar 22.

Golder Associates Ltd., 500-4260 Still Creek Drive, Burnaby, BC V5C 6C6, Canada.

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.
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http://dx.doi.org/10.1016/j.envint.2013.02.009DOI Listing
May 2013

Development of histopathological indices in a commercial marine bivalve (Ruditapes decussatus) to determine environmental quality.

Aquat Toxicol 2013 Jan 27;126:442-54. Epub 2012 Aug 27.

IMAR - Instituto do Mar, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, Caparica, Portugal.

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.
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http://dx.doi.org/10.1016/j.aquatox.2012.08.013DOI Listing
January 2013

Hepatic proteome changes in Solea senegalensis exposed to contaminated estuarine sediments: a laboratory and in situ survey.

Ecotoxicology 2012 May 24;21(4):1194-207. Epub 2012 Feb 24.

Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia da, IMAR-Instituto do Mar, Universidade Nova de Lisboa, Caparica, Portugal.

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.
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http://dx.doi.org/10.1007/s10646-012-0874-7DOI Listing
May 2012

Can the integration of multiple biomarkers and sediment geochemistry aid solving the complexity of sediment risk assessment? A case study with a benthic fish.

Environ Pollut 2012 Feb 4;161:107-20. Epub 2011 Nov 4.

IMAR - Instituto do Mar, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.

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.
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http://dx.doi.org/10.1016/j.envpol.2011.10.010DOI Listing
February 2012

Transcriptomic analyses in a benthic fish exposed to contaminated estuarine sediments through laboratory and in situ bioassays.

Ecotoxicology 2011 Nov 10;20(8):1749-64. Epub 2011 Jun 10.

IMAR-Instituto do Mar, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, 2829-516, Caparica, Portugal.

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.
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http://dx.doi.org/10.1007/s10646-011-0708-zDOI Listing
November 2011

Assessment of the genotoxic potential of contaminated estuarine sediments in fish peripheral blood: laboratory versus in situ studies.

Environ Res 2011 Jan 20;111(1):25-36. Epub 2010 Oct 20.

IMAR-Instituto do Mar, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.

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.
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http://dx.doi.org/10.1016/j.envres.2010.09.011DOI Listing
January 2011

Estuarine ecological risk based on hepatic histopathological indices from laboratory and in situ tested fish.

Mar Pollut Bull 2011 Jan 29;62(1):55-65. Epub 2010 Sep 29.

IMAR-Instituto do Mar, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.

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.
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http://dx.doi.org/10.1016/j.marpolbul.2010.09.009DOI Listing
January 2011

Evaluation of the potential of the common cockle (Cerastoderma edule L.) for the ecological risk assessment of estuarine sediments: bioaccumulation and biomarkers.

Ecotoxicology 2010 Nov 18;19(8):1496-512. Epub 2010 Aug 18.

IMAR-Instituto do Mar, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, 2829-516, Monte de Caparica, Portugal.

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.
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http://dx.doi.org/10.1007/s10646-010-0535-7DOI Listing
November 2010

Biochemical endpoints on juvenile Solea senegalensis exposed to estuarine sediments: the effect of contaminant mixtures on metallothionein and CYP1A induction.

Ecotoxicology 2009 Nov 15;18(8):988-1000. Epub 2009 Jul 15.

Instituto do Mar, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, 2829-516, Caparica, Portugal.

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.
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http://dx.doi.org/10.1007/s10646-009-0373-7DOI Listing
November 2009

Ecological risk assessment of sediment management areas: application to Sado Estuary, Portugal.

Ecotoxicology 2009 Nov 14;18(8):1165-75. Epub 2009 Jul 14.

Department of Science and Technology, Portuguese Distance Learning University, R. Fernão Lopes, 9, 1269-001, Lisbon, Portugal.

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.
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http://dx.doi.org/10.1007/s10646-009-0372-8DOI Listing
November 2009

Histological biomarkers in liver and gills of juvenile Solea senegalensis exposed to contaminated estuarine sediments: a weighted indices approach.

Aquat Toxicol 2009 May 27;92(3):202-12. Epub 2008 Dec 27.

IMAR-Instituto do Mar, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.

Young juvenile Solea senegalensis were exposed to three sediments with distinct contamination profiles collected from a Portuguese estuary subjected to anthropogenic sources of contamination (the Sado estuary, western Portugal). Sediments were surveyed for metals (cadmium, chromium, copper, nickel, lead and zinc), a metalloid (arsenic) and organic contaminants (polycyclic aromatic hydrocarbons, polychlorinated biphenyls and a pesticide, dichloro-diphenyl-trichloroethane plus its metabolites), as well as total organic matter, redox potential and particle fine fraction. The fish were exposed to freshly collected sediments in a 28-day laboratorial assay and collected for histological analyses at days 0 (T(0)), 14 (T(14)) and 28 (T(28)). Individual weighted histopathological indices were obtained, based on presence/absence data of eight and nine liver and gill pathologies, respectively, and on their biological significance. Although livers sustained more severe lesions, the sediments essentially contaminated by organic substances caused more damage to both organs than the sediments contaminated by both metallic and organic contaminants, suggesting a possible synergistic effect. Correlation analyses showed that some alterations are linked, forming distinctive histopathological patterns that are in accordance with the severity of lesions and sediment characteristics. The presence of large eosinophilic bodies in liver and degeneration of mucous cells in gills (a first-time described alteration) were some of the most noticeable alterations observed and were related to sediment organic contaminants. Body size has been found to be negatively correlated with histopathological damage in livers following longer term exposures. It is concluded that histopathological indices provide reliable and discriminatory data even when biomonitoring as complex media as natural sediments. It is also concluded that the effects of contamination may result not only from toxicant concentrations but also from their interactions, relative potency and sediment characteristics that ultimately determine bioavailability.
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http://dx.doi.org/10.1016/j.aquatox.2008.12.009DOI Listing
May 2009

Genotoxic damage in Solea senegalensis exposed to sediments from the Sado Estuary (Portugal): effects of metallic and organic contaminants.

Mutat Res 2008 Jun 30;654(1):29-37. Epub 2008 Apr 30.

IMAR - Instituto do Mar, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, 2829-516 Monte de Caparica, Portugal.

Juvenile Solea senegalensis (Senegalese sole) were exposed to freshly collected sediments from three sites of the Sado Estuary (West-Portuguese coast) in 28-day laboratory assays in order to assess the ecological risk from sediment contaminants, by measuring two genotoxicity biomarkers in peripheral blood: the percentage of Erythrocyte Nuclear Abnormalities (ENA) by use of an adaptation of the micronucleus test, and the percentage of DNA strand-breakage (DNA-SB) with the Comet assay. Sediments were surveyed for metallic (Cr, Ni, Cu, Zn, As, Cd and Pb) and organic (PAHs (polycyclic aromatic hydrocarbons), PCBs (polychlorinated biphenyls) and DDTs (dichloro-diphenyl-trichloroethane)) contaminants. Sediments from site A (farthest from hotspots of contamination) were found to be the least contaminated and weaker inducers of genotoxic damage, whereas sediments from sites B (urban influence) and C (affected by industrial effluents and agricultural runoffs) were responsible for a very significant increase in both ENA and DNA-SB, site B being most contaminated with metals and site C mainly with organic pollutants, especially PAHs and PCBs . Analysis of genotoxic effects showed a strong correlation between the concentrations of PAHs and PCBs and both biomarkers at sampling times T(14) and T(28), while the amounts of Cu, As, Cd and Pb were less strongly correlated, and at T(28) only, with ENA and DNA-SB. These results show that organic contaminants in sediment are stronger and faster acting genotoxic stressors. The results also suggest that metals may have an inhibitory effect on genotoxicity when interacting with organic contaminants, at least during early exposure. ENA and DNA-SB do not show a linear relationship, but a strong correlation exists between the overall increase in genotoxicity caused by exposure to sediment, confirming that they are different, and possibly non-linked effects that respond similarly to exposure. Although the Comet assay showed enhanced sensitivity, the two analyses are complementary and suitable for the biomonitoring of sediment contaminants in a benthic species like S. senegalensis.
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http://dx.doi.org/10.1016/j.mrgentox.2008.04.007DOI Listing
June 2008

Toxicity ranking of estuarine sediments on the basis of Sparus aurata biomarkers.

Environ Toxicol Chem 2007 Mar;26(3):444-53

CIMAR-LA/CIIMAR-Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Laboratório de Ecotoxicologia, Rua dos Bragas, 177, 4050-123 Porto, Portugal.

Sparus aurata biomarkers were used to rank sediments from the Sado River estuary (Portugal) according to their toxicity. Initially, the activities of liver ethoxyresorufin-O-deethylase, liver and gill glutathione S-transferases, muscle lactate dehydrogenase, and brain acetylcholinesterase were tested in a laboratory bioassay with the reference compound benzo[a]pyrene. Enzymatic activities were determined in different tissues of fish exposed for 48, 96, or 240 h to three concentrations of benzo[a]pyrene (25, 50, and 100 microg/L). Induction of liver ethoxyresorufin-O-deethylase was observed at all the exposure periods and concentrations, suggesting a continuous response of this system to toxicant exposure. Induction of liver glutathione S-transferases activity was only observed after 240 h of exposure, whereas gill glutathione S-transferases activity was significantly inhibited at all the exposure periods, suggesting a direct or indirect effect of the toxicant on these enzymes. Inhibition of lactate dehydrogenases activity was only observed after 96 h of exposure to 25 microg/L of benzo[a]pyrene. No significant effects were observed on acetylcholinesterase activity, suggesting that cholinergic function of S. aurata is not affected by benzo[a]pyrene. In a second phase, fish were exposed for 240 h to sediments collected at five sites of the Sado River estuary, and the same biomarkers were analyzed. For all the enzymes assayed, significant differences among sites were found. In this study, the battery of biomarkers used allowed to discrimination among sites with different types of contamination, levels of contamination, or both, after multivariate data analysis. Discrimination of sites was similar to the ranking provided by a more complex and parallel study (including chemical analysis of sediments, macrobenthic community analysis, amphipod mortality toxicity tests, and sea urchin abnormality embryo assays), suggesting its suitability to evaluate the toxicity of estuarine sediments.
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http://dx.doi.org/10.1897/06-119r.1DOI Listing
March 2007

Delineation of estuarine management areas using multivariate geostatistics: the case of Sado Estuary.

Environ Sci Technol 2003 Sep;37(18):4052-9

IMAR, Department of Exact and Technological Sciences of the Portuguese Distance Learning University, R. Escola Politecnica 147, 1269-001 Lisbon, Portugal.

The Sado Estuary is a coastal zone located in the south of Portugal where conflicts between conservation and development exist because of its location near industrialized urban zones and its designation as a natural reserve. The aim of this paper is to evaluate a set of multivariate geostatistical approaches to delineate spatially contiguous regions of sediment structure for Sado Estuary. These areas will be the supporting infrastructure of an environmental management system for this estuary. The boundaries of each homogeneous area were derived from three sediment characterization attributes through three different approaches: (1) cluster analysis of dissimilarity matrix function of geographical separation followed by indicator kriging of the cluster data, (2) discriminant analysis of kriged values of the three sediment attributes, and (3) a combination of methods 1 and 2. Final maximum likelihood classification was integrated into a geographical information system. All methods generated fairly spatially contiguous management areas that reproduce well the environment of the estuary. Map comparison techniques based on kappa statistics showed thatthe resultant three maps are similar, supporting the choice of any of the methods as appropriate for management of the Sado Estuary. However, the results of method 1 seem to be in better agreement with estuary behavior, assessment of contamination sources, and previous work conducted at this site.
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http://dx.doi.org/10.1021/es0262075DOI Listing
September 2003