A contínua entrada de metais pesados nos ambientes aquáticos constitui uma potencial ameaça aos ecossistemas naturais devido à ação tóxica direta em organismos aquáticos. Nos ambientes aquáticos, os organismos estão expostos a metais tanto dissolvidos na água como aqueles presentes na cadeia trófica. Um maior conhecimento sobre o papel do alimento como rota adicional de exposição a metais ou como um possível retentor de sua toxicidade para invertebrados aquáticos é necessário. Considerando-se a importância dos metais na contaminação ambiental, bem como a necessidade de melhor entendimento das interações desses elementos nos sistemas aquáticos, o presente estudo visou a avaliar a sensibilidade de espécies fitoplanctônicas (Selenastrum capricornutum e Microcystis aeruginosa) e de espécies zooplanctônicas (Daphnia similis e Ceriodaphnia dubia) aos metais cádmio e cromo e os efeitos tóxicos desses elementos em tais organismos. O crescimento celular, a concentração de clorofila, o biovolume e o peso seco das algas foram analisados quando as espécies algais foram expostas aos metais por meio de testes de toxicidade aguda. Testes de toxicidade aguda e crônica com o zooplâncton aos metais também foram realizados e o efeito de diferentes densidades algais (alta, média e baixa) sobre a toxicidade dos metais aos cladóceros foi avaliado. Além disso, algas foram expostas aos metais, oferecidas como alimento a C. dubia e os efeitos tóxicos crônicos foram investigados. Os resultados demonstraram que S. capricornutum foi mais sensível ao cádmio e M. aeruginosa foi mais sensível ao cromo, sendo essa diferença relacionada à capacidade das algas para reter os metais. Com o aumento de ambos os metais, houve uma diminuição na densidade celular, na taxa de crescimento, na clorofila e no peso seco das algas. A presença de diferentes densidades de S. capricornutum não alterou significativamente o valor da CE(I)50; 48h aos metais para D. similis, mas a elevada densidade de M. aeruginosa reduziu a toxicidade do cádmio para o dafinídeo. A alta densidade de alimento (106 céls/mL) influenciou negativamente a reprodução e a sobrevivência de C. dubia quando exposta a concentrações subletais dos metais em solução. Alimento exposto à metais, quando fornecido em alta e em média densidade, também afetou a sobrevivência e a reprodução dos organismos-teste. Apesar de a água ser uma importante rota de exposição aos metais para os organismos aquáticos, o alimento deve ser considerado uma via de contaminação adicional. / The continuous input of heavy metals into aquatic systems constitutes a potential threat to natural ecosystems because of the direct toxic action on aquatic organisms. In aquatic ecosystems, the organisms are exposed to dissolved metals in the water as to metals presents in the food chain. A larger knowledge about paper of food as an additional route of exposure to metals or as possible retainer of its toxicity for aquatic organisms is necessary. Considering the importance of metals in contamination of aquatic ecosystems and the need of better understanding of the interactions of those elements in the aquatic ecosystems as well, the aim of this study was to evaluate the sensibility of phytoplankton species (Selenastrum capricornutum and Microcystis aeruginosa) and zooplankton species (Daphnia similis and Ceriodaphnia dubia) to cadmium and chromium metals and the toxic effects of those elements in such organisms. Analysed of cellular growth, chlorophyll concentration, biovolume and dry weight of the algae were carried out when algal species were exposed to metals. Acute and chronic toxicity tests with the zooplankton were also accomplished and the effect of different algal densities (high, middle and low) on toxicity of metals to cladoceran was evaluated. Alga S. capricornutum was exposed to metals, supplied as food to C. dubia and chronic toxicity effects were investigated. The results demonstrated that S. capricornutum was more sensitive to cadmium and M. aeruginosa was more sensitive to chromium, this difference was related the capacity of the algae to retain metals. Cell density, growth rate, chlorophyll and dry weight of the algae were reduced with increase of both metals. The presence of different density of S. capricornutum does not alter the value of EC50 to metals for D. similis, but high density of M. aeruginosa reduced the toxicity of cadmium for daphnid. High food density (106 cells/mL) influenced negatively on reproduction and survival of C. dubia when this organism was exposed to sublethal concentrations of metals in solution. Food exposed to metals, when it was supplied at high and middle density, also affected survival and reproduction of the test organisms. Although the water to be considered a important route of exposure of metals for aquatic organisms, the food should be considered an additional source of toxicity.

Florescimentos de cianobactérias têm sido cada vez mais frequentemente detectados em reservatórios do Estado de São Paulo, especialmente naqueles da bacia do Médio rio Tietê. A presença de cianobactérias pode acarretar prejuízos à qualidade da água nestes ambientes, em razão de seu potencial tóxico à biota aquática, incluindo riscos à saúde humana. O presente estudo teve por objetivo analisar a estrutura da comunidade zooplanctônica de três reservatórios do Médio rio Tietê, SP (Barra Bonita, Bariri e Ibitinga) e sua relação com as cianobactérias presentes nas florações, com ênfase nos efeitos da toxicidade destas sobre o dafinídeo Ceriodaphnia silvestrii, uma espécie nativa. Para tanto, amostragens foram realizadas nos períodos de junho e setembro de 2008, e janeiro e maio de 2009. Foram efetuadas medições de diversos parâmetros físicos, químicos e biológicos em cada reservatório. As florações de cianobactérias foram coletadas com redes de plâncton, e armazenadas para análise e quantificação de cianotoxinas e também para a realização de ensaios ecotoxicológicos. Verificou-se que a comunidade zooplanctônica dos reservatórios é dominada por copépodos e rotíferos na maior parte das camadas de água dos reservatórios. Os copépodes Cyclopoida foram mais abundantes que os Calanoida, com grande representatividade de formas jovens (náuplios e copepoditos). A espécie de Cladocera Bosminam longirostris e grande parte das espécies de rotifera, como Brachionus calyciflorus foram frequentes em todas as represas, indicando que podem ter estratégias para coexistir com as toxinas dos blooms de cianobactérias. As concentrações de microcistinas LR foram detectadas em todas as amostras de florações dos reservatórios do médio rio Tietê, com concentrações variando e 18,2 a 100 \'mü\'g/L. Os testes de toxicidade aguda revelaram que os extratos brutos das florações de cianobactérias foram tóxicos ao dafínideo Ceriodaphnia silvestrii, provocando inibição dos movimentos natatórios mesmo em baixas concentrações de microcistina-LR, podendo portanto influenciar negativamente a biota aquática. / Cyanobacteria blooms are increasingly being detected in São Paulo state reservoirs, particularly in those of middle Tietê river basin. The presence of cyanobacteria can cause deterioration of water quality in these systems due to its potential toxicity to the aquatic biota, and also risks to human health. The aim of the present srtudy was to analyse the structure of the zooplankton community in three reservoirs placed in middle Tietê river basin, SP (Barra Bonita, Bariri and Ibitinga) and its relationships with blooms of cyanobacteria, with emphasis on its toxic effects upon the daphnid Ceriodaphnia silvestrii, a native species. Sampling was carried out in June and September 2008 and January and May 2009. Measurements of several physical, chemical and biological parameters were carried out in each reservoir. Samples of cyanobacteria blooms were taken with phytoplankton nets and properly kept for posterior analysis of species composition, cyanotoxin quantification and also for acute toxicity testing. It was found that zooplankton communities in the reservoirs are dominated by rotifers and copepods in most of the water layers sampled. The cyclopoid copepods were more abundant than calanoid ones with great representativiness of the young forms (nauplii and copepodids). The Cladocera species Bosmina longirostris and some species of Rotifera as Brachionus calyciflorus were frequent in all reservoirs, indicating that they might have strategies to cope with the cyanobacteria bloom toxicity. Microcystin LR concentrations were detected in all samples of blooms from Middle Tietê River reservoirs with concentrations varying from 18,2 to 100 \'mü\'g/ L. Acute toxicity tests revealed that raw extracts from cyanobacteria scums were toxic to the daphnid Ceriodaphnia silvestrii, causing immobilization of natatory movements even at low LR microcystin concentrations, thus negatively affecting the aquatic biota.

Research in the multidisciplinary science of ecotoxicology is crucial to assess injuries to ecosystem resources from chemical spills or other stressors used to support environmental decision-making. Established guidelines recommend the use of non-standard native species in toxicity investigations. This work focused on the use of native species for aquatic toxicity assessment to make more relevant conclusions on the potential for adverse biological effects to occur as a result to single chemical exposures or exposures to a complex mixture like oil. We apply these studies to investigate petroleum product impacts from the Deepwater Horizon incident and concerns for metal toxicity in estuarine environments using a new model organism. Data generated from comprehensive toxicity testing programs were used in the first probabilistic risk assessment of Deepwater Horizon oil toxicity highlighting a lack of appropriate data and representative phyla. Novel toxicity study methods and a stress-response index were developed and demonstrated sensitivity and success in using the starlet anemone in ecotoxicology studies. Swim performance was used as new method to investigate sublethal indicators of stress resulting in varied responses from sheepshead minnows and Florida pompano. These studies further our ability for better laboratory-to-field extrapolation and for decision-making. The use of native species and complex mixtures like oil presented novel challenges in conducting aquatic toxicity studies. Special emphasis is placed on the necessity to understand the appropriate laboratory conditions for native species not typically held in the laboratory and maintaining study parameters to obtain quality data for more accurate interpretation and replication.

Uno de los principales factores que amenazan a los anfibios es la contaminación del medio por diferentes sustancias químicas, lo que hace necesario incrementar el conocimiento que se tiene del impacto de estos compuestos sobre los anfibios.En la presente Tesis Doctoral se estudió el impacto, en diferentes condiciones experimentales, del cloruro amónio, nitrito sódico y nitrato sódico, de manera aislada o combinada, sobre la rana común, Pelophylax perezi (Seoane, 1885). Además, se intentó proporcionar una visión general de los efectos de la contaminación sobre los anfibios mediante la realización de un meta-análisis.Los resultados obtenidos permiten concluir que la contaminación afectó negativamente a la supervivencia de los anfibios y a otros parámetros subletales. Sin embargo, la contaminación puede conducir la evolución de los anfibios. Finalmente, las condiciones experimentales demostraron tener una gran importancia a la hora de establecer el impacto de un agente estresante sobre los anfibios. / Chemical pollution is one of the major factors threatening amphibians, which makes necessary to perform further studies to assess its impact on amphibians.The present PhD thesis looks at the impact, in different experimental venues, of ammonium chloride, sodium nitrite and sodium nitrate, either isolated or combined, on the Iberian water frog, Pelophylax perezi (Seoane, 1885). Moreover, an overview of pollution effects on amphibianswas provided by conducting a meta-analysis.The results obtained allowed to conclude that pollution negatively affected amphibian survival, as well as other sublethal endpoints. Neverthelesss, pollution may drive the evolution in amphibians. Finally, experimental venues were revealed to show a great relevance when assessing the impact of a stressing factor on amphibians.

Derivat de 3 capítols de la tesi s'han publicat dos articles en revistes científiques i un capítol de llibre: Chapter 3, pg. 61 : Corcoll et al. 2012-HdB Environ Chem-book chapter 4 Chapter 4, pg. 81: Corcoll et al. 2011- Chl-a fluorescence parameters as biomarkers of metal toxicity in fluvial biofilms Chapter 5, pg. 117: Corcoll et al. 2012- The effect of metals on photosynthesis processes and diatom metrics on biofilm from a metal-contaminated river / Metal pollution in rivers is in great concern with human activities in the fluvial watershed. This thesis aims to investigate the potential use of chl-a fluorescence parameters as biomarkers of metal toxicity, and to find cause-effect relationships between metal exposures, other environmental factor (i.e. light), and functional and structural biofilm responses. This thesis demonstrates that the use of chl-a fluorescence parameters allows detect early effects on biofilms caused by zinc toxicity, both in the laboratory as in polluted rivers. In microcosm experiments, the use of chl-a fluorescence parameters allows evaluates structural changes on photosynthetic apparatus and in algal groups’ composition of biofilms long-term exposed to zinc. In order to evaluate the effects of chronic metal pollution in rivers, it is recommended the use of biofilm translocation experiments and the use of a multi-biomarker approach. / La contaminació per metalls en els rius està principalment lligada a l’activitat humana que té lloc a la conca fluvial. Aquesta tesi té per objectiu principal avaluar l'ús potencial dels paràmetres de fluorescència de la chl-a com a biomarcadors de toxicitat per metalls, i trobar relacions causa-efecte entre l’exposició dels metalls, altres factors ambientals (ex. la llum), i les respostes funcionals i estructurals del biofilms. Aquesta tesi demostra que els paràmetres de fluorescència de la chl-a permeten detectar alteracions ràpides del biofilm causades per la toxicitat del zinc, tan al laboratori com en rius contaminats. En microcosmos, els paràmetres de fluorescència de la chl-a permeten avaluar canvis estructurals en l’aparell fotosintètic i en la composició dels grups algals dels biofilms exposats crònicament al zinc. Per avaluar els efectes de la contaminació crònica per metalls en rius es recomana fer experiments de translocació de biofilms i utilitzar una aproximació de multi-biomarcador.

In the European Union an environmental risk assessment is required for the registration of new chemicals, biocides, pesticides and pharmaceuticals. In order to avoid the release of potential hazardous substances, various ecotoxicity tests are performed, including acute and chronic fish tests. As a consequence of the new program of the European Union “Registration, Evaluation and Authorisation of Chemicals” (REACH) the number of animal experiments for environmental risk assessment is expected to increase remarkably within the next years. On the other hand there is a strong societal demand for reducing the number of animal tests by using alternative in vitro models. According to EU directives, investigations using non-human vertebrate embryos are considered pain free in vitro methods and are therefore accepted as alternatives to animal experiments. For the acute fish test, the Danio rerio embryo test (DarT) has been established as a replacement method and included in national regulations at least for waste water (German Waste Water Dues Law). However, no alternatives for chronic fish tests are currently available. The overall goal of this thesis was to work towards such a replacement by extending DarT zu Gene-DarT. Toxicants will initially interact at the molecular level with consequences for physiology, fitness and survival. The analysis of gene expression patterns may unravel elements of these molecular events before any phenotypic changes are visible. The hypothesis of this thesis therefore was that chemical-sensitive genes in embryos exposed in a conventional DarT may indicate toxic impact of substances at sub-acute concentrations and thus enhance the sensitivity of the embryo toxicity test. Furthermore, unlike the conventional DarT-endpoints, gene expression analysis will provide insights into mechanistic processes underlying toxicity. The 3,4-dichloroaniline (3,4-DCA), which is used as a reference compound in the DarT, was selected as model chemical in this thesis. In a first step, differentially expressed genes in embryos exposed to 3,4-DCA were identified by microarray technology and RT-PCR techniques. Six dose-dependent significant differentially expressed genes were identified. These genes were involved in biotransformation pathways (cyp1a, ahr2), stress response (nrf2, maft, ho-1) and cell cycle control (fzr1). Differential expression upon 3,4-DCA exposure was detected below the LOEC (lowest observed effect concentration = 6.2 µM) of survival or developmental disorders of the embryo test (0.78 µM and above). For the validation of stage specific sensitivity, genes were also analysed in post-hatched stages. Extension of exposure to post-hatched stages resulted in a differential expression at lower concentrations as for the embryonic stages, indicating an improved sensitivity due to stage-specific sensitivity or exposure time. To confirm the adaptive function of the 3,4-DCA-sensitive genes, embryonic mRNA abundance was experimentally manipulated by knock down and overexpression. By injection of sense (mRNA) or antisense (siRNA) RNA in one-cell-stages of embryos, the transcript levels of genes were transiently enhanced or repressed in embryos exposed to 3,4-DCA. mRNA injection of the genes cyp1a, ho-1 and nrf2 reduced the number of embryos with 3,4-DCA-induced malformations. In contrast, siRNA injections for the same genes led to an increase in the severity and frequency of developmental disorders. The results clearly indicate the adaptive functions of the investigated genes or their corresponding proteins. This study demonstrates that the analysis of chemical-sensitive gene expression shows the potential to increase the sensitivity of conventional toxicity tests. The analysis of gene expression also provides additional mechanistic information for toxic action, e.g. in the presented study, the involvement of Ah-receptor regulated pathways as an adaptive response. Furthermore, the presented data indicate that functional manipulations, using mRNA and siRNA-injection, are suitable to evaluate the role of differentially expressed genes for toxicity.

Levels of selected metals and persistent organic pollutants (POPs) were investigated in sediment and fillet tissue of the sharptooth catfish (Clarias gariepinus), from sites along the Orange-Vaal River system, South Africa. A histological assessment was done on the livers, kidneys, and gills of the fish sampled to determine morphological changes. The sediment and fish sampling sites were selected up- and downstream of major pollution sources such as mining, industrial and agriculture. The concentrations of the metals in the fish and sediment was determined with an inductively coupled plasma mass spectrometry and the POPs with a high resolution gas chromatographyhigh resolution mass spectrometer. Indices were calculated to describe the quality of the sediment The enrichment factor (Ef) of individual heavy metals evaluated elevation in levels above natural geology. The geo-accumulation index (Igeo) determined the degree of pollution by the enrichment levels of the individual metals. The pollution effect of the total mixture of the heavy metals was investigated by the metal pollution index (MPI) and pollution load index (PLI). Ecological risk was determined by calculating the sediment quality guideline index (SQG-I) and a sediment quality index (SQI) to determine the quality of the sediment. For the SQG-I and SQI, international sediment quality guidelines were used, since South Africa does not have them. The bio-accumulation factor (BF) was calculated between sediment and fish. A limited human health risk assessment was done for the consumption of Clarias gariepinus. A semi-quantitative histopathological assessment was preformed and alterations found were numerically described with the aid of mean organ indices. The POPs values were very low. The Igeo and Ef of Se, Hg, Ag and Au were the highest at all the sites. Parys had the most metals that were enriched to different degrees, but Rooipoort had the highest MPI and PLI. The SQG-I indicated that the sites had a moderate chance of posing an ecological risk to its biota, except for Rooipoort that had a high toxic probability. The SQI classified Rooipoort as “fair” in terms of sediment quality and the rest of the sites as “good”. The semi-quantitative histology based assessment results showed that the mean organ and fish indices fell within class 1 (normal tissue structure with slight histological alterations) or class 2 (normal tissue structure with moderate histological alterations). The mean gill, -liver and kidney indices for all the sites fell in class 1. The mean fish index for all the sites however, fell in class 2. The human health risk assesment showed high risk for non-carcinogenic effects from Ag, Hg, As and Cr if fish from the sample sites were to be consumed. The results from this study identified that the river system is polluted by anthropogenic activities. Results showed that the pollutants of concern in the system were ultimately Ag, Hg and PFOS. Although the morphology of Clarias gariepinus was not altered, the results indicated that the Orange-Vaal River system is polluted and that these fish is unsafe for human consumption. / Thesis (MSc (Environmental Sciences))--North-West University, Potchefstroom Campus, 2013.

Levels of selected metals and persistent organic pollutants (POPs) were investigated in sediment and fillet tissue of the sharptooth catfish (Clarias gariepinus), from sites along the Orange-Vaal River system, South Africa. A histological assessment was done on the livers, kidneys, and gills of the fish sampled to determine morphological changes. The sediment and fish sampling sites were selected up- and downstream of major pollution sources such as mining, industrial and agriculture. The concentrations of the metals in the fish and sediment was determined with an inductively coupled plasma mass spectrometry and the POPs with a high resolution gas chromatographyhigh resolution mass spectrometer. Indices were calculated to describe the quality of the sediment The enrichment factor (Ef) of individual heavy metals evaluated elevation in levels above natural geology. The geo-accumulation index (Igeo) determined the degree of pollution by the enrichment levels of the individual metals. The pollution effect of the total mixture of the heavy metals was investigated by the metal pollution index (MPI) and pollution load index (PLI). Ecological risk was determined by calculating the sediment quality guideline index (SQG-I) and a sediment quality index (SQI) to determine the quality of the sediment. For the SQG-I and SQI, international sediment quality guidelines were used, since South Africa does not have them. The bio-accumulation factor (BF) was calculated between sediment and fish. A limited human health risk assessment was done for the consumption of Clarias gariepinus. A semi-quantitative histopathological assessment was preformed and alterations found were numerically described with the aid of mean organ indices. The POPs values were very low. The Igeo and Ef of Se, Hg, Ag and Au were the highest at all the sites. Parys had the most metals that were enriched to different degrees, but Rooipoort had the highest MPI and PLI. The SQG-I indicated that the sites had a moderate chance of posing an ecological risk to its biota, except for Rooipoort that had a high toxic probability. The SQI classified Rooipoort as “fair” in terms of sediment quality and the rest of the sites as “good”. The semi-quantitative histology based assessment results showed that the mean organ and fish indices fell within class 1 (normal tissue structure with slight histological alterations) or class 2 (normal tissue structure with moderate histological alterations). The mean gill, -liver and kidney indices for all the sites fell in class 1. The mean fish index for all the sites however, fell in class 2. The human health risk assesment showed high risk for non-carcinogenic effects from Ag, Hg, As and Cr if fish from the sample sites were to be consumed. The results from this study identified that the river system is polluted by anthropogenic activities. Results showed that the pollutants of concern in the system were ultimately Ag, Hg and PFOS. Although the morphology of Clarias gariepinus was not altered, the results indicated that the Orange-Vaal River system is polluted and that these fish is unsafe for human consumption. / Thesis (MSc (Environmental Sciences))--North-West University, Potchefstroom Campus, 2013.

Στην παρούσα μελέτη πραγματοποιήθηκε εκτίμηση της τοξικότητας των τελικών εκροών πριν και μετά το στάδιο της απολύμανσης (με τη χρήση της μεθόδους της χλωρίωσης) από το σταθμό βιολογικής επεξεργασίας των αστικών αποβλήτων της Πάτρας με την χρήση βιοδεικτών (biotest). Η μελέτη των τοξικών επιπτώσεων αυτών των εκροών και από τα δύο στάδια πραγματοποιήθηκε σε οργανισμούς-Βιοδείκτες τόσο των γλυκών όσο και αλμυρών υδάτων, όπως οι οργανισμοί Thamnocephalus platyurus και Artemia franciscana (με τη μορφή βιοτέστ Thamnotoxkit F και Artoxkit MTM αντίστοιχα), όσο και σε φυτικά είδη, όπως τα Sorghum saccharatum, Lepidum sativum και Sinapis alba (με τη μορφή Phytotoxkit). Επιπλέον έγινε ανίχνευση του μικροβιακού φορτίου πριν και μετά το στάδιο της χλωρίωσης, για την εκτίμηση της αποτελεσματικότητας της μεθόδου απολύμανσης των εκροών, καθώς και χημική ανάλυσή τους. Σύμφωνα με τα αποτελέσματα της παρούσας μελέτης, οι τελικές εκροές υγρών αποβλήτων που καταλήγουν στο στάδιο της απολύμανσης, με τη μέθοδο της χλωρίωσης παρουσιάζουν μεγάλες διακυμάνσεις τόσο στις φυσικοχημικές παραμέτρους και στη συγκέντρωση βαρέων μετάλλων που μετρήθηκαν, όσο και στην τοξικότητα που μπορεί να επιφέρουν στους οργανισμούς που χρησιμοποιήθηκαν. Τα αποτελέσματα της παρούσας μελέτης έδειξαν την αποτελεσματικότητα της μεθόδου όσο αφορά τη μείωση του μικροβιακού φορτίου των τελικών εκροών. Αντίθετα, η μελέτη τοξικότητας των τελικών εκροών με τη χρήση οργανισμών τόσο του γλυκού όσο και του αλμυρού νερού (Thamnocephalus platyurus και Artemia franciscana αντίστοιχα), καθώς και σε φυτικούς οργανισμούς (Sorgum saccharatum, Sinapsis alba και Lepidum sativum) έδειξε σημαντικές εποχικές μεταβολές στην επαγωγή τοξικών φαινομένων. Συγκεκριμένα, οι εκροές (μετά το στάδιο της χλωρίωσης effluents) φαίνεται να είναι λιγότερο τοξικές για τους οργανισμούς του αλμυρού νερού, συγκριτικά με τις τοξικές επιπτώσεις που προκαλούν οι εκροές πριν το στάδιο της χλωρίωσης (influents). Αντίθετα, οι εκροές που προκύπτουν μετά το στάδιο της χλωρίωσης παρουσιάζουν μεγαλύτερη τοξικότητα σε οργανισμούς του γλυκού νερού, σε σχέση με τις επιπτώσεις που προκαλούν οι εκροές πριν το στάδιο της χλωρίωσης, ενώ παρατηρήθηκε σημαντική αναστολή της αυξητικής ικανότητας των ειδών Sorgum saccharatum και Sinapsis alba σε κάθε περίπτωση. Συμπερασματικά, από τα αποτελέσματα της παρούσας μελέτης, φαίνεται η αποτελεσματικότητα της μεθόδου απολύμανσης των τελικών εκροών, όσο αφορά την απαλλαγή τους από μολυσματικούς παράγοντες, αλλά αναδεικνύονται τα προβλήματα τοξικότητας που μπορεί να επιφέρουν οι τελικές εκροές σε οργανισμούς των τελικών υδάτινων αποδεκτών (γλυκό και αλμυρό νερό), καθώς και η αναποτελεσματικότητα της χρήσης των τελικών εκροών σε δραστηριότητες όπως η άρδευση, λόγω της αναστολής που προκαλεί η χρήση τους σε φυτικούς οργανισμούς. / In this study was estimated the toxicity of the final effluents before and after the stage of disinfection (using the method of chlorination) in the wastewater treatment plant of Patras using bioindicators (biotest).The study of the toxic effects of these effluents and of the two stages was performed on organisms bioindicators both in freshwater and salt water, such as Thamnocephalus platyurus and Artemia franciscana (in the form of biotest Thamnotoxkit F and Artoxkit MTM respectively) and on plant species such as Sorghum saccharatum, Lepidum sativum and Sinapis alba (in the form of Phytotoxkit). Moreover the treated effluents were tested for microbiological parameters before and after the stage of chlorination, to assess the effectiveness of the method of disinfection of effluents, and also a chemical analysis was performed. According to the results of this study, the final effluents of wastewater that end in the process of disinfection, with the method of chlorination, vary widely both in physicochemical parameters and heavy metals that were measured, and as well the toxicity that can cause to organisms used. The results of this study showed the effectiveness of the method as regards reducing the microbial load of the final effluents. Instead, the study of final effluents toxicity using organisms of both fresh and saltwater (Thamnocephalus platyurus and Artemia franciscana, respectively) and in plant organisms (Sorgum saccharatum, Sinapsis alba and Lepidum sativum) showed significant seasonal changes in the induction of toxic reactions. Specifically, the effluents (after-chlorination effluents) seem to be less toxic for organisms of salt water, compared with the toxic effects caused by effluents before the stage of chlorination (influents). However, the effluents after the stage of chlorination are toxic in freshwater organisms compared to the effects caused by effluents before the stage of chlorination, while there was significant inhibition of growth capacity of species Sorgum saccharatum, Sinapsis alba in each case. In conclusion, the results of this study show the effectiveness of the method of disinfection of final effluents, as regards the discharge from contaminants, but highlighted the problems of toxicity that the final effluents can cause to organisms in the final water receiver (fresh and salty water), and the inefficiency of using of final effluents in activities such as irrigation, due to the inhibition caused by their use in plant organisms.

O objetivo do presente deste trabalho foi avaliar a toxicidade aguda, crônica e a genotoxicidade sobre E. andrei causadas por solo recém-contaminado com óleo lubrificante usado e após biorremediação por diferentes estratégias, após 22 meses, e paralelamente ao estudo de ecotoxicidade, foi conduzida uma investigação comparativa de três métodos de extração de HTP e HPA de solos para análise cromatográfica. A comparação das técnicas de extração evidenciou que para HTP, a técnica de extração acelerada por solvente-ASE foi a que melhor recuperou n-alcanos; já para as frações HRP e MCNR as técnicas soxhlet e micro-ondas-MARS não apresentaram diferenças significativas e foram melhores que ASE. Para HPA, a técnica de extração por soxhlet foi a que apresentou melhor recuperação em todos os solos. O teste de mortalidade apresentou, aos 14 dias, taxas crescentes de mortalidade de 10 6%, 20 0%, 73 25%, 93 12% e 100 0% para amostras de CONT (solo controle, sem contaminação artificial), BIOS (solo contaminado com 5% de OLU e biorremediado por bioestimulo), BIOA1 (solo contaminado com 5% de OLU e biorremediado por bioestimulo + bioaumento com adição de 10% de RSU maturado), e BIOA2 (solo contaminado com 5% de OLU e biorremediado por bioestimulo + bioaumento com adição de 10% de RSU semi-maturado) e OLU (solo contaminado com 5% de OLU), respectivamente. Aos 28 dias, entretanto, BIOS e OLU apresentaram taxas de mortalidade de 97 % 6 % e de 100 % 0 % respectivamente, valores estes significativamente superiores ao CONT. Foram observadas deformações anatômicas nos indivíduos mantidos em BIOS e OLU, assim como diminuição da biomassa em todas as amostras, evidenciando efeitos crônicos. O teste de reprodução, aos 28 dias, foram observadas grandes quantidades de indivíduos jovens nos solos biorremediados e recém-contaminado. No entanto, aos 56 dias houve uma diminuição dessas formas e o controle (CONT) exibiu uma quantidade maior de formas juvenis. O teste de densidade e viabilidade celular mostrou ser indicador sensível para toxicidade crônica apresentando queda nos solos BIOS e OLU em relação ao CONT com diferenças significativas (p <0.05). Não foram observados micronúcleos nos solos em estudo. Tal observação reforça a necessidade de testes de ecotoxicidade para avaliar a real eficácia de tecnologias de tratamento. / The aim of this study was to evaluate this acute toxicity, chronic and genotoxicity on E. andrei caused by freshly contaminated soil with used lubricating oil and after bioremediation by different strategies, after 22 months, and alongside ecotoxicity study, we conducted a comparative study of three methods of extraction and HTP HPA soil for chromatographic analysis. Comparison of extraction techniques for HTP showed that the technique of accelerated solvent extraction-ASE had the best recovery of n-alkanes, whereas for fractions and HRP MCNR soxhlet techniques and microwave-MARS and no significant differences were better than ASE. For HPA, the soxhlet extraction technique showed the best recovery in all soils. The mortality test showed , at the 14th day, growing mortality rates of 10 6% 20 0%, 73 25% 93 12% and 100 0% for samples CONT (ground control without contamination artificial ), BIOS (soil contaminated with 5% of OLU and bioremediated for biostimulation) BIOA1 (soil contaminated with 5% of OLU and bioremediated for biostimulation + bioaugmentation by adding 10% of MSW matured) and BIOA2 (soil contaminated with 5% bioremediated of OLU and for biostimulation + bioaugmentation by adding 10% of MSW semi-matured) and OLU (soil contaminated with 5% OLU), respectively. At the 28th day, however, OLU BIOS and mortality rates were 97% 6% and 100% 0%, respectively, values which are significantly higher than CONT. Anatomical deformations have been observed in individuals kept in BIOS and OLU, as well as decreased biomass in all samples, suggesting chronic effects. The reproduction test, at the 28th day, were found large quantities of juveniles in bioremediated soils and freshly contaminated soil. However, at the 56th day there was a decrease of these forms and control (CONT) exhibited a greater amount of juveniles. The >test> density and cell viability test showed to be a sensitive indicator for chronic toxicity in soils having decrease BIOS and OLU compared to CONT with significant differences (p <0.05). No micronuclei were observed in soils under study. This observation reinforces the need for ecotoxicity tests to assess the true efficacy of treatment technologies.