Avaliação de risco ambiental na indústria em regime de responsabilidade ambiental

O presente relatório surgiu na sequência do estágio curricular realizado na empresa Envienergy - Ambiente e Energia, Lda. O tema do estágio resultou da necessidade de responsabilização das empresas pelos danos ambientais que possam surgir da sua atividade, segundo as disposições da Diretiva n.º 2004/35/CE, de 21 de Abril, transposta para o regime jurídico nacional pelo Decreto-Lei n.º 147/2008, de 29 de julho, também conhecido por Diploma da Responsabilidade Ambiental. No âmbito deste regime de responsabilidade, desenvolveu-se e aplicou-se a um caso de estudo, uma metodologia de avaliação de riscos ambientais, com posterior cálculo da garantia financeira. O caso de estudo foi uma empresa industrial da área da cerâmica, de médias dimensões, cliente da Envienergy. A metodologia consistiu numa apreciação do estado inicial do ambiente envolvente à empresa em estudo (designada como CERÂMICA), levantamento dos riscos da sua atividade, formulação de cenários de acidentes, avaliação da severidade e da probabilidade dos riscos de acidente e estimativa dos custos de reparação e compensação ambiental dos danos que a atividade possa provocar (a garantia financeira). Segundo esta metodologia, o caso de estudo requer uma garantia financeira no valor de 26.125€, correspondente ao valor financeiro necessário para assegurar que seja possível à indústria avaliada a responsabilização ambiental por danos provocados pela sua atividade. A metodologia também prevê a sugestão de medidas de redução de risco e, considerando a aplicação dessas medidas, a reavaliação dos riscos e da garantia financeira. Desta reavaliação resultou uma garantia financeira estimada em 5.403€. A avaliação de riscos ambientais feita à indústria cerâmica serviu para testar e comprovar a adaptabilidade da metodologia a um caso real. Os resultados obtidos foram satisfatórios, e a metodologia está apta a ser aplicada a casos de estudo de dimensão semelhantes ao caso de estudo avaliado neste relatório.

Cartografia geoquímica da ilha de Santiago com uma densidade de amostragem média/baixa

A ilha de Santiago é a maior do arquipélago de Cabo Verde, apresenta uma área de 991 km2, com um comprimento e largura máximos de 54,9 km e 29 km, respectivamente, e 1392 m de maior altitude. As condições climáticas e a erosão são alguns dos problemas naturais do arquipélago de Cabo Verde. Além disso, a intervenção humana no ambiente superficial revela-se muitas vezes inadequada e com forte impacto. A construção em solos com aptidão agrícola ou florestal, as actividades industriais, a deposição de materiais sólidos ou líquidos de forma inadequada, as práticas agrícolas incorrectas e intensivas, o uso abusivo de pesticidas e fertilizantes, a rega com água contaminada, a sobreexploração de aquíferos que levam muitas vezes à salinização, etc. têm enorme impacto em termos de contaminação de solos, águas superficiais e subterrâneas nas áreas envolventes. Por conseguinte, o conhecimento da variabilidade geoquímica natural é fundamental para a resolução de questões de índole económica, ambiental e de ordenamento do território, médica, e jurídica. A necessidade de construir uma base de dados de geoquímica georeferenciada que caracterize o ambiente superficial da ilha de Santiago foi a principal motivação para a realização deste estudo. Realizou-se um levantamento geoquímico de 337 amostras de sedimentos de corrente e 249 amostras de solos na ilha de Santiago, tendo sido seguidas as recomendações do Projecto Internacional IGCP 259 não só na fase de amostragem, mas também nas fases seguintes de preparação, análise, tratamento dos dados e elaboração de mapas. Determinaram-se os teores, na fracção < 2 mm, para 36 elementos – 9 elementos maiores (Al, Ca, Fe, K, Mg, Mn, Na, P, Ti) e 27 elementos vestigiais (Ag, As, Au, B, Ba, Bi, Cd, Co, Cr, Cu, Ga, Hg, La, Mo, Ni, Pb, S, Sb, Sc, Se, Sr, Th, Tl, U, V, W, Zn). Efectuou-se ainda a análise textural e estudou-se a composição mineralógica de cerca de 25% das amostras. Analisaram-se, também, 103 amostras de rochas, colhidas nas várias formações da ilha de Santiago, tendo sido determinados os teores de K2O, Na2O, Fe2O3(T), MnO, Sc, Cr, Co, Zn, Ga, As, Br, Rb, Zr, Sb, Cs, Ba, Hf, Ta, W, Th e U e REE, a fim de se fazer uma comparação com os teores destes elementos encontrados nos solos e sedimentos de corrente, averiguando se a sua variação é ou não essencialmente condicionada pela geoquímica da rocha-mãe. Os padrões geoquímicos obtidos através dos mapas de distribuição espacial foram correlacionados com a natureza da rocha mãe, o tipo de solo, e ainda com algumas fontes de contaminação. A interpretação dos resultados foi realizada não só pela observação dos mapas geoquímicos, mas também após análise estatística dos conjuntos de dados obtidos, e apoiada em informação diversa disponível. A utilização da Análise de Componentes Principais permitiu distinguir associações entre elementos químicos, quer de origem geogénica quer antropogénica. Foram ainda elaborados mapas de distribuição espacial de vários índices multielementares de importância ambiental, como o Índice de Acidificação Al/(Ca+Mg+K), Índice de Combi, Índice de Avaliação de Risco Ambiental e Índices de Enriquecimento/Contaminação para vários grupos de elementos considerados como “primary pollutant metals”.

From genes to population: effects of toxicants on Enchytraeus albidus

Nowadays, a systems biology approach is both a challenge as well as believed to be the ideal form of understanding the organisms’ mechanisms of response. Responses at different levels of biological organization should be integrated to better understand the mechanisms, and hence predict the effects of stress agents, usable in broader contexts. The main aim of this thesis was to evaluate the underlying mechanisms of Enchytraeus albidus responses to chemical stressors. Therefore, there was a large investment on the gene library enrichment for this species, as explained ahead. Overall, effects of chemicals from two different groups (metals and pesticides) were assessed at different levels of biological organization: from genes and biochemical biomarkers to population endpoints. Selected chemicals were: 1) the metals cadmium and zinc; 2) the insecticide dimethoate, the herbicide atrazine and the fungicide carbendazim. At the gene and sub-cellular level, the effects of time and dosage were also adressed. Traditional ecotoxicological tests - survival, reproduction and avoidance behavior - indicated that pesticides were more toxic than metals. Avoidance behaviour is extremely important from an ecological point of view, but not recommended to use for risk assessment purposes. The oxidative stress related experiment showed that metals induced significant effects on several antioxidant enzyme activities and substrate levels, as well as oxidative damage on the membrane cells. To increase the potential of our molecular tool to assess transcriptional responses, the existing cDNA library was enriched with metal and pesticide responding genes, using Suppression Subtractive Hybridization (SSH). With the sequencing information obtained, an improved Agilent custom oligonucleotide microarray was developed and an EST database, including all existing molecular data on E. albidus, was made publicly available as an interactive tool to access information. With this microarray tool, most interesting and novel information on the mechanisms of chemical toxicity was obtained, with the identification of common and specific key pathways affected by each compound. The obtained results allowed the identification of mechanisms of action for the tested compounds in E. albidus, some of which are in line with the ones known for mammals, suggesting across species conserved modes of action and underlining the usefulness of this soil invertebrate as a model species. In general, biochemical and molecular responses were influenced by time of exposure and chemical dosage and these allowed to see the evolution of events. Cellular energy allocation results confirmed the gene expression evidences of an increased energetic expenditure, which can partially explain the decrease on the reproductive output, verified at a later stage. Correlations found throughout this thesis between effects at the different levels of biological organization have further improved our knowledge on the toxicity of metals and pesticides in this species.

Accidental release of hazardous gases: modelling and assessing risk

The renewed concern in assessing risks and consequences from technological hazards in industrial and urban areas continues emphasizing the development of local-scale consequence analysis (CA) modelling tools able to predict shortterm pollution episodes and exposure effects on humans and the environment in case of accident with hazardous gases (hazmat). In this context, the main objective of this thesis is the development and validation of the EFfects of Released Hazardous gAses (EFRHA) model. This modelling tool is designed to simulate the outflow and atmospheric dispersion of heavy and passive hazmat gases in complex and build-up areas, and to estimate the exposure consequences of short-term pollution episodes in accordance to regulatory/safety threshold limits. Five main modules comprising up-to-date methods constitute the model: meteorological, terrain, source term, dispersion, and effects modules. Different initial physical states accident scenarios can be examined. Considered the main core of the developed tool, the dispersion module comprises a shallow layer modelling approach capable to account the main influence of obstacles during the hazmat gas dispersion phenomena. Model validation includes qualitative and quantitative analyses of main outputs by the comparison of modelled results against measurements and/or modelled databases. The preliminary analysis of meteorological and source term modules against modelled outputs from extensively validated models shows the consistent description of ambient conditions and the variation of the hazmat gas release. Dispersion is compared against measurements observations in obstructed and unobstructed areas for different release and dispersion scenarios. From the performance validation exercise, acceptable agreement was obtained, showing the reasonable numerical representation of measured features. In general, quality metrics are within or close to the acceptance limits recommended for ‘non-CFD models’, demonstrating its capability to reasonably predict hazmat gases accidental release and atmospheric dispersion in industrial and urban areas. EFRHA model was also applied to a particular case study, the Estarreja Chemical Complex (ECC), for a set of accidental release scenarios within a CA scope. The results show the magnitude of potential effects on the surrounding populated area and influence of the type of accident and the environment on the main outputs. Overall the present thesis shows that EFRHA model can be used as a straightforward tool to support CA studies in the scope of training and planning, but also, to support decision and emergency response in case of hazmat gases accidental release in industrial and built-up areas.

Genotoxic risk of herbicides to Anguilla anguilla L.

No contexto dos contaminantes aquáticos, os herbicidas são considerados como um dos grupos mais perigosos. Uma vez aplicados, estes são facilmente transportados para cursos de água, quer devido a uma pulverização pouco cuidada ou devido a fenómenos de escorrência superficial e/ou subterrânea. A presença destes agroquímicos no ambiente tem vindo a ser associada a efeitos nefastos em organismos não-alvo, como é o caso dos peixes. Contudo, existe ainda uma grande lacuna no que diz respeito à informação científica relacionada com o seu impacto genotóxico. Deste modo, a presente tese foi delineada com o intuito de avaliar o risco genotóxico em peixes de duas formulações de herbicidas: o Roundup®, que tem como princípio activo o glifosato, e o Garlon®, que apresenta o triclopir na base da sua constituição, produtos estes largamente utilizados na limpeza de campos agrícolas, assim como em florestas. Foi ainda planeado desenvolver uma base de conhecimento no que diz respeito aos mecanismos de dano do ADN. Como último objectivo, pretendeu-se contribuir para a mitigação dos efeitos dos agroquímicos no biota aquático, nomeadamente em peixes, fornecendo dados científicos no sentido de melhorar as práticas agrícolas e florestais. Este estudo foi realizado adoptando a enguia europeia (Anguilla anguilla L.) como organismo-teste, e submetendo-a a exposições de curta duração (1 e 3 dias) dos produtos comerciais mencionados, em concentrações consideradas ambientalmente realistas. Para a avaliação da genotoxicidade foram aplicadas duas metodologias: o ensaio do cometa e o teste das anomalias nucleares eritrocíticas (ANE). Enquanto o ensaio do cometa detecta quebras na cadeia do ADN, um dano passível de ser reparado, o aparecimento das ANE revela lesões cromossomais, sinalizando um tipo de dano de difícil reparação. O ensaio do cometa foi ainda melhorado com uma nova etapa que incluiu a incubação com enzimas de reparação (FPG e EndoIII), permitindo perceber a ocorrência de dano oxidativo no ADN. No que diz respeito ao Roundup®, o envolvimento do sistema antioxidante como indicador de um estado próoxidante foi também alvo de estudo. Uma vez que as referidas formulações se apresentam sob a forma de misturas, o potencial genotóxico dos seus princípios activos foi também avaliado individualmente. No caso particular do Roundup®, também foram estudados o seu surfactante (amina polietoxilada; POEA) e o principal metabolito ambiental (ácido aminometilfosfórico; AMPA). Os resultados obtidos mostraram a capacidade do Roundup® em induzir tanto dano no ADN (em células de sangue, guelras e fígado) como dano cromossómico (em células de sangue). A investigação sobre o possível envolvimento do stresse oxidativo demonstrou que o tipo de dano no ADN varia com as concentrações testadas e com a duração da exposição. Deste modo, com o aumento do tempo de exposição, os processos relacionados com o envolvimento de espécies reactivas de oxigénio (ERO) ganharam preponderância como mecanismo de dano no ADN, facto que é corroborado pela activação do sistema antioxidante observado nas guelras, assim como pelo aumento dos sítios sensíveis a FPG em hepatócitos. O glifosato e o POEA foram também considerados genotóxicos. O POEA mostrou induzir uma maior extensão de dano no ADN, tanto comparado com o glifosato como com a mistura comercial. Apesar de ambos os componentes contribuirem para a genotoxicidade da formulação, a soma dos seus efeitos individuais nunca foi observada, apontando para um antagonismo entre eles e indicando que o POEA não aumenta o risco associado ao princípio activo. Deste modo, realça-se a necessidade de regulamentar limiares de segurança para todos os componentes da formulação, recomendando, em particular, a revisão da classificação do risco do POEA (actualmente classificado com “inerte”). Uma vez confirmada a capacidade do principal metabolito do glifosato – AMPA – em exercer dano no ADN assim como dano cromossómico, os produtos da degradação ambiental dos princípios activos assumem-se como um problema silencioso, realçando assim a importância de incluir o AMPA na avaliação do risco relacionado com herbicidas com base no glifosato. A formulação Garlon® e o seu princípio activo triclopir mostraram um claro potencial genotóxico. Adicionalmente, o Garlon® mostrou possuir um potencial genotóxico mais elevado do que o seu princípio activo. No entanto, a capacidade de infligir dano oxidativo no ADN não foi demonstrada para nenhum dos agentes. No que concerne à avaliação da progressão do dano após a remoção da fonte de contaminação, nem os peixes expostos a Roundup® nem os expostos a Garlon® conseguiram restaurar completamente a integridade do seu ADN ao fim de 14 dias. No que concerne ao Roundup®, o uso de enzimas de reparação de lesões específicas do ADN associado ao teste do cometa permitiu detectar um aparecimento tardio de dano oxidativo, indicando deste modo um decaimento progressivo da protecção antioxidante e ainda uma incapacidade de reparar este tipo de dano. O período de pós-exposição correspondente ao Garlon® revelou uma tendência de diminuição dos níveis de dano, apesar de nunca se observar uma completa recuperação. Ainda assim, foi evidente uma intervenção eficiente das enzimas de reparação do ADN, mais concretamente as direccionadas às purinas oxidadas. A avaliação das metodologias adoptadas tornou evidente que o procedimento base do ensaio do cometa, que detecta apenas o dano nãoespecífico no ADN, possui algumas limitações quando comparado com a metodologia que incluiu a incubação com as enzimas de reparação, uma vez que a última mostrou reduzir a possibilidade de ocorrência de resultados falsos negativos. Os dois parâmetros adoptados (ensaio do cometa e teste das ANE) demonstraram possuir aptidões complementares, sendo assim recomendado a sua utilização conjunta com vista a efectuar uma avaliação mais adequada do risco genotóxico. Globalmente, os resultados obtidos forneceram indicações de grande utilidade para as entidades reguladoras, contribuindo ainda para a (re)formulação de medidas de conservação do ambiente aquático. Neste sentido, os dados obtidos apontam para a importância da avaliação de risco dos herbicidas incluir testes de genotoxicidade. A magnitude de risco detectada para ambas as formulações adverte para a necessidade de adopção de medidas restritivas em relação à sua aplicação na proximidade de cursos de água. Como medidas mitigadoras de impactos ambientais, aponta-se o desenvolvimento de formulações que incorporem adjuvantes selecionados com base na sua baixa toxicidade.

Características e especificidades de jovens agressores sexuais

Nos últimos anos o estudo da violência sexual juvenil tem vindo a atrair a atenção dos serviços de saúde mental, de justiça juvenil e de políticas públicas, bem como de vários investigadores. Teoricamente existem duas perspetivas explicativas da ocorrência das agressões sexuais cometidas por adolescentes. A perspetiva generalista sugere que os crimes sexuais cometidos por jovens são mais uma manifestação de tendências delinquenciais genéricas, em que as agressões sexuais constituem apenas uma parte do comportamento antissocial do adolescente. A segunda abordagem, denominada de perspetiva especialista, entende que os jovens agressores sexuais se distinguem dos outros adolescentes agressores, argumentando que existem diferentes fatores explicativos das agressões sexuais de outras agressões delinquentes. A presente investigação, composta por cinco estudos, teve como objetivo obter resultados que pudessem contribuir para a discussão internacional sobre qual das perspetivas parece explicar de modo mais apropriado o comportamento sexualmente agressivo de jovens menores de idade. Para o efeito recorreu-se a uma amostra total de 118 adolescentes agressores sexuais (61 violadores e 57 abusadores sexuais de crianças), tendo sido efetuadas análises comparativas com 112 jovens agressores não sexuais e 98 não agressores num conjunto de dimensões (características demográficas, tipológicas, criminais, problemas de comportamento, tendências antissociais, características familiares, sociais e comunitárias e interesses sexuais). Os resultados permitiram observar algumas características diferenciadoras de jovens agressores sexuais por violação de jovens agressores sexuais de crianças. Possibilitaram, igualmente, a observação de características semelhantes entre jovens agressores sexuais e jovens agressores não sexuais, sugerindo que em algumas dimensões são, genericamente, análogas. A exceção parece centrar-se em torno das variáveis relacionadas com a sexualidade (conhecimentos e interesses sexuais atípicos). As implicações destes resultados são discutidas em torno da avaliação psicológica e da avaliação do risco de reincidência, bem como na intervenção e prevenção de comportamentos de agressão sexual juvenil.

Toxicogenomics of natural and anthropogenic effectors in eleutheroembryos

The introduction of chemicals into the environment by human activities may represent a serious risk to environmental and human health. Environmental risk assessment requires the use of efficient and sensitive tools to determine the impact of contaminants on the ecosystems. The use of zebrafish for the toxicity assessment of pharmaceuticals, drugs, and pollutants, is becoming well accepted due to zebrafish unique advantages for the screening of compounds for hazard identification. The aim of the present work is to apply toxicogenomic approaches to identify novel biomarkers and uncovered potential modes of action of classic and emergent contaminants able to disrupt endocrine systems, such as the Retinoic Acid Receptor, Retinoid X Receptor and the Aryl Hydrocarbon Receptor. This study relies on different nuclear and cytosolic protein receptors and other conditional (ligand- or stress- activated) transcriptional factors that are intimately involved in the regulation of defensome genes and in mechanisms of chemical toxicity. The transcriptomic effects of organic compounds, endogenous compounds, and nanoparticles were analysed during the early stages of zebrafish development. Studying the gene expression profiles of exposed and unexposed organisms to pollutants using microarrays allowed the identification of specific gene markers and to establish a "genetic code" for the tested compounds. Changes in gene expression were observed at toxicant concentrations that did not cause morphological effects. Even at low toxicant concentrations, the observed changes in transcript levels were robust for some target genes. Microarray responses of selected genes were further complemented by the real time quantitative polymerase chain reaction (qRT-PCR) methodology. The combination of bio-informatic, toxicological analyses of differential gene expression profiles, and biochemical and phenotypic responses across the treatments allowed the identification of uncovered potential mechanisms of action. In addition, this work provides an integrated set of tools that can be used to aid management-decision making by improving the predictive capability to measure environmental stress of contaminants in freshwater ecosystems. This study also illustrates the potential of zebrafish embryos for the systematic, large-scale analysis of chemical effects on developing vertebrates.

Development of open models and tools for seismic risk assessment: application to Portugal

The exponential growth of the world population has led to an increase of settlements often located in areas prone to natural disasters, including earthquakes. Consequently, despite the important advances in the field of natural catastrophes modelling and risk mitigation actions, the overall human losses have continued to increase and unprecedented economic losses have been registered. In the research work presented herein, various areas of earthquake engineering and seismology are thoroughly investigated, and a case study application for mainland Portugal is performed. Seismic risk assessment is a critical link in the reduction of casualties and damages due to earthquakes. Recognition of this relation has led to a rapid rise in demand for accurate, reliable and flexible numerical tools and software. In the present work, an open-source platform for seismic hazard and risk assessment is developed. This software is capable of computing the distribution of losses or damage for an earthquake scenario (deterministic event-based) or earthquake losses due to all the possible seismic events that might occur within a region for a given interval of time (probabilistic event-based). This effort has been developed following an open and transparent philosophy and therefore, it is available to any individual or institution. The estimation of the seismic risk depends mainly on three components: seismic hazard, exposure and vulnerability. The latter component assumes special importance, as by intervening with appropriate retrofitting solutions, it may be possible to decrease directly the seismic risk. The employment of analytical methodologies is fundamental in the assessment of structural vulnerability, particularly in regions where post-earthquake building damage might not be available. Several common methodologies are investigated, and conclusions are yielded regarding the method that can provide an optimal balance between accuracy and computational effort. In addition, a simplified approach based on the displacement-based earthquake loss assessment (DBELA) is proposed, which allows for the rapid estimation of fragility curves, considering a wide spectrum of uncertainties. A novel vulnerability model for the reinforced concrete building stock in Portugal is proposed in this work, using statistical information collected from hundreds of real buildings. An analytical approach based on nonlinear time history analysis is adopted and the impact of a set of key parameters investigated, including the damage state criteria and the chosen intensity measure type. A comprehensive review of previous studies that contributed to the understanding of the seismic hazard and risk for Portugal is presented. An existing seismic source model was employed with recently proposed attenuation models to calculate probabilistic seismic hazard throughout the territory. The latter results are combined with information from the 2011 Building Census and the aforementioned vulnerability model to estimate economic loss maps for a return period of 475 years. These losses are disaggregated across the different building typologies and conclusions are yielded regarding the type of construction more vulnerable to seismic activity.

Nanosensor for assessing the risk of a cardiovascular disease

The incidence of cardiovascular diseases (CVD) has been increasing according to the European and global statistics. Thus, the development of new analytical devices, such as biosensors for assessing the risk of CVD could become a valuable approach for the improvement of healthcare service. In latest years, the nanotechnology has provided new materials with improved electronic properties which have an important contribution in the transduction mechanism of biosensors. Thus, in this thesis, biosensors based on field effect transistors with single-walled carbon nanotubes (NTFET) were developed for the detection of C-reactive protein (CRP) in clinical samples, that is, blood serum and saliva from a group of control patients and a group of CVD risk patients. CRP is an acute-phase protein, which is commonly known as the best validated biomarker for the assessment of CVD, the single-walled carbon nanotubes (SWCNT) were applied as transduction components, and the immunoreaction (interaction between the CRP antigen and the antibodies specific to CRP) was used as the mechanism of molecular recognition for the label-free detection of CRP. After the microfabrication of field effect transistors (FET), the screening of the most important variables for the dispersion of SWCNT, the assemblage of NTFET, and their application on standard solutions of CRP, it was found that NTFET respond accurately to CRP both in saliva and in serum samples, since similar CRP levels were found with the NTFET and the traditional methodology (ELISA technique). On the other hand, a strong correlation between salivary and serum CRP was found with NTFET, which means that saliva could be used, based on non-invasive sampling, as an alternative fluid to blood serum. It was also shown that NTFET could discriminate control patients from CVD risk patients, allowing the determination of a cut-off value for salivary CRP of 1900 ng L-1, which corresponds to the well established cut-off of 3 mg L-1 for CRP in serum, constituting an important finding for the possible establishment of a new range of CRP levels based on saliva. According to the data provided from the volunteer patients regarding their lipoprotein profile and lifestyle factors, it was concluded that the control and the CVD risk patients could be separated taking into account the various risk factors established in literature as strong contributors for developing a CVD, such as triglycerides, serum CRP, total cholesterol, LDL cholesterol, body mass index, Framingham risk score, hypertension, dyslipidemia, and diabetes mellitus. Thus, this work could provide an additional contribution to the understanding of the association of biomarkers levels in serum and saliva samples, and above all, cost-effective, rapid, label-free, and disposable NTFET were developed, based on a noninvasive sampling, for the assessment of CVD risk, thus constituting a potential point-of-care technology.

Toxicidade de químicos em mistura: o caso da albufeira do Alqueva

In the environment humans and biota are generally exposed to chemical mixtures rather than individual chemicals. Therefore, when assessing the environmental risk of chemicals, it is important to consider chemical mixtures and their possible interactions. The main objective of this work focused on the environmental risk assessment of pesticides found in the water of the Alqueva reservoir and their binary combinations. In this aquatic ecosystem several pesticides were above of the environmental quality standards. But in addition, there were several sampling points of the reservoir where ecotoxicity was observed despite the presence of these contaminants at low concentrations. Here, a component-based approach was used to assess the effects of the pesticide mixtures. The effects of the binary combinations of four herbicides, atrazine (ATR), terbuthylazine (TER), simazine (SIM) and metolachlor (MET), on the growth rate of the microalgae Pseudokirchneriella subcapitata and the effects of the binary combinations of the s-triazine herbicides ATR and TER and the insecticide chlorpyrifos (CPF) on the swimming behaviour and acetylcholinesterase (AChE) activity of the zebrafish Danio rerio were assessed using the two reference models of concentration addition (CA) and independent action (IA). Moreover, the combined effects of the herbicides (ATR, TER and MET) and the insecticide CPF were also tested on the swimming behaviour and AChE activity of the aquatic midge Chironomus riparius after the cholinesterases characterization. In this risk characterization, the calculated risk quotients for the herbicides ATR, TER, SIM and MET were higher than 1, meaning that these herbicides present a high risk for the Alqueva ecosystem. As expected, the microalgae P. subcapitata was the most sensitive species to the herbicides. However, despite these herbicides pose no or low risk to other aquatic organisms tested in this study, with EC50 values much higher than the concentrations found in this aquatic ecosystem, they are able to increase the toxic effects of CPF when they are tested in binary mixtures. Moreover, the risk quotients of mixtures of these herbicides present simultaneously in three different locations of the reservoir were also higher than 1, so this confirms the fact that these herbicides when present in mixtures, present a greater risk for this ecosystem than the expected considering each single chemical by its own.

Challenges in mercury speciation and fractionation in soil and sediment

This investigation focused on the development, test and validation of methodologies for mercury fractionation and speciation in soil and sediment. After an exhaustive review of the literature, several methods were chosen and tested in well characterised soil and sediment samples. Sequential extraction procedures that divide mercury fractions according to their mobility and potential availability in the environment were investigated. The efficiency of different solvents for fractionation of mercury was evaluated, as well as the adequacy of different analytical instruments for quantification of mercury in the extracts. Kinetic experiments to establish the equilibrium time for mercury release from soil or sediment were also performed. It was found that in the studied areas, only a very small percentage of mercury is present as mobile species and that mobility is associated to higher aluminium and manganese contents, and that high contents of organic matter and sulfur result in mercury tightly bound to the matrix. Sandy soils tend to release mercury faster that clayey soils, and therefore, texture of soil or sediment has a strong influence on the mobility of mercury. It was also understood that analytical techniques for quantification of mercury need to be further developed, with lower quantification limits, particularly for mercury quantification of less concentrated fractions: water-soluble e exchangeable. Although the results provided a better understanding of the distribution of mercury in the sample, the complexity of the procedure limits its applicability and robustness. A proficiency-testing scheme targeting total mercury determination in soil, sediment, fish and human hair was organised in order to evaluate the consistency of results obtained by different laboratories, applying their routine methods to the same test samples. Additionally, single extractions by 1 mol L-1 ammonium acetate solution, 0.1 mol L-1 HCl and 0.1 mol L-1 CaCl2, as well as extraction of the organometallic fraction were proposed for soil; the last was also suggested for sediment and fish. This study was important to update the knowledge on analytical techniques that are being used for mercury quantification, the associated problems and sources of error, and to improve and standardize mercury extraction techniques, as well as to implement effective strategies for quality control in mercury determination. A different, “non chemical-like” method for mercury species identification was developed, optimised and validated, based on the thermo-desorption of the different mercury species. Compared to conventional extraction procedures, this method has advantages: it requires little to no sample treatment; a complete identification of species present is obtained in less than two hours; mercury losses are almost neglectable; can be considered “clean”, as no residues are produced; the worldwide comparison of results obtained is easier and reliable, an important step towards the validation of the method. Therefore, the main deliverables of this PhD thesis are an improved knowledge on analytical procedures for identification and quantification of mercury species in soils and sediments, as well as a better understanding of the factors controlling the behaviour of mercury in these matrices.

Effect assessment of nanoparticles toxicity in the terrestrial compartment

Over 11 million tons of nanomaterials (NMs) have been produced in 2012 and predictions point the increase in production. Despite predictions and extended usage via consumer products and industry, the understanding of the potential impact of these materials on the environment is virtually absent. The main aim of this thesis is to understand how a selected group of nanomaterials (metal based particles) may impact soil invertebrates, with special focus on the mechanisms of response. Since a case-by-case Environmental Risk Assessment (ERA) of all the emerging contaminants (particularly NMs) is impossible, among others due to time and cost reasons, to gain understanding on the mechanism of action and response is very important to reach a common paradigm. Understanding the modes of action provides predictive characters in cross particle extrapolation. Besides, it also provides insight for the production of new and sustainable materials. Overall, the effects of the selected NMs (Copper and Silver, Titanium and Zirconium oxides) and the respective salt forms, were investigated at the gene expression (using high-throughput tools, microarray and qPCR technology), biochemical (using enzymatic assays for analysis of oxidative stress markers) and organism (survival and reproduction as in OECD test guidelines) levels, this using standard soil species (Enchytraeus albidus, Enchytraeus crypticus, Eisenia fetida). Gene expression analysis provided valuable information on the mechanisms affected by each of the NMs. The gene expression profile highlighted a (nano)material signature and the effect of the duration of exposure. The functional analyses integrated with the biochemical and organism data, revealed a good understanding power. The biochemical parameters (oxidative stress related) were distinct across the materials and also influenced by duration of exposure and concentration. The standardized organismal responses differed the least between the various materials. The overall outcome is that, in this context of NMs effect assessment, gene expression and enzymatic assays introduced a very important knowledge gap, which could not had been achieved by the standard organismal effects alone. A reoccurring issue with some metal based NMs is the possible dissolution and subsequent release of ions that then causes toxicity e.g. Cu-NPs or Ag-NPs release Cu2+ or Ag+. The oxidation state of the particles was investigated, although this was not the focus of the thesis. The study of fate, e.g. dissolution of NPs, is also only in its beginning and the appropriate techniques are currently being developed. The results showed a specific nanoparticle effect. The UV exposure with titanium dioxide nanoparticles increased its effect.

Seismic vulnerability assessment of slender masonry structures

Slender masonry structures are distributed all over the world and constitute a relevant part of the architectural and cultural heritage of humanity. Their protection against earthquakes is a topic of great concern among the scientific community. This concern mainly arises from the strong damage or complete loss suffered by this group of structures due to catastrophic events and the need and interest to preserve them. Although the great progress in technology, and in the knowledge of seismology and earthquake engineering, the preservation of these brittle and massive structures still represents a major challenge. Based on the research developed in this work it is proposed a methodology for the seismic risk assessment of slender masonry structures. The proposed methodology was applied for the vulnerability assessment of Nepalese Pagoda temples which follow very simple construction procedure and construction detailing in relation to seismic resistance requirements. The work is divided in three main parts. Firstly, particular structural fragilities and building characteristics of the important UNESCO classified Nepalese Pagoda temples which affect their seismic performance and dynamic properties are discussed. In the second part the simplified method proposed for seismic vulnerability assessment of slender masonry structures is presented. Finally, the methodology proposed in this work is applied to study Nepalese Pagoda temples, as well as in the efficiency assessment of seismic performance improvement solution compatible with original cultural and technological value.

Derivation of soil screening values for metals in Portuguese natural soil

The increasing human activity has been responsible by profound changes and a constinuos degradation of the soil compartment in all the European territory. Some European policies are appearing focusing soil’s protection and the management of contaminated sites, in order to recover land for other uses. To regulate the risk assessment and the management of contaminated soils, many European member states adopted soil guideline values, as for example soil screnning values (SSV).These values are particularly useful for the the first tier of the Ecological Risk Assessment (ERA) processes of contaminated sites,especially for a first screening of sites requiring a more site-specific evaluation. Hence, the approriate definition of regional SSVs will have relevant economic impacts in the management of contaminated sites. Portugal is one of European Member States that still lack these soil guideline values. In this context, this study gaves a remarkable contribution in the generation of ecotoxicological data for soil microbiological parameters, terrestrial plants and invertebrates for the derivation of SSVs for uranium (U), cadmium (Cd) and copper (Cu), using a Portuguese natural soil, representative of a dominant type of soil in the Portuguese territory. SSVs were derived based on two methods proposed by the the Technical Guidance Document for Risk Assessment of the European Commission; namely the assessment factor method (AF) and the species sensitivity distribution (SSD) method (with some adaptations). The outputs of both methods were compared and discussed. Further, this study laid the foundation for a deeper reflection about the cut-off (hazard concentration for a given percentage of species - HCps) to be estimated from the SSDs, and to be selected for the derivation of SSVs, with the adequate level of protection. It was proven that this selection may vary for different contaminants, however a clear justification should be given, in each case. The SSvs proposed in this study were for: U (151.4 mg U kg-1dw), Cd (5.6 mg Cd kg-1dw), and Cu (58.5 mg Cu kg-1dw) These values should now be tested for their descriminating power of soils with different levels of contamination. However, this studies clarifies the approach that should be followed for the derivation of SSVs for other metals and organic contaminants, and for other dominant types of Portuguese natural soils.

Metais em plantas e algas : acumulação e potencial aplicação em processos de remediação

The present work reports the study of the bioaccumulation of potentially toxic elements (cadmium, lead and mercury) by marine macroalgae (Ulva lactuca, Fucus vesiculosus and Gracilaria gracilis), abundant in the coast and estuarine systems worldwide. These organisms proved to be capable of withstanding moderate multi-metallic contamination (environmentally relevant concentrations), incorporating high amounts of metal in their tissues. The high removal percentages achieved, in particular for mercury (99%), demonstrate the potential of these algae as a basis for a new biotechnological treatment of saline waters contaminated with metals (more efficient, cost-effective and environmentally friendly than conventional methods). U. lactuca was considered the most promising due to the better performance presented. The comparison between the bioaccumulation and biosorption processes suggested that in some cases the use of the living organism will have advantages over the application of biomass, due to the simplicity of the overall process, and the lower residual concentration of metal achieved in the solution (especially for Cd). The transfer and accumulation of Hg by terrestrial plants (Brassica juncea and Lolium perenne) in agricultural fields near a contaminated industrial area was also studied. Despite the low bioaccumulation factors found (<1), there were high Hg content in plants (up to 84 mg kg-1 in roots and up 6.9 mg kg-1 in shoots, dry weight). Daily intake estimates for grazing animals (cows and sheep) pointed to the potential risk to human health derived from consumption of their meat. The results highlighted the important role that plants and algae may have in protection, risk assessment and remediation of environmental systems contaminated with metals.