Yes / Shell beads appear to have been one of the earliest examples of personal adornments. Marine shells identified far from the shore evidence long-distance transport and imply networks of exchange and negotiation. However, worked beads lose taxonomic clues to identification, and this may be compounded by taphonomic alteration. Consequently, the significance of this key early artefact may be underestimated. We report the use of bulk amino acid composition of the stable intra-crystalline proteins preserved in shell biominerals and the application of pattern recognition methods to a large dataset (777 samples) to demonstrate that taxonomic identification can be achieved at genus level. Amino acid analyses are fast (<2 hours per sample) and micro-destructive (sample size <2 mg). Their integration with non-destructive techniques provides a valuable and affordable tool, which can be used by archaeologists and museum curators to gain insight into early exploitation of natural resources by humans. Here we combine amino acid analyses, macro- and microstructural observations (by light microscopy and scanning electron microscopy) and Raman spectroscopy to try to identify the raw material used for beads discovered at the Early Bronze Age site of Great Cornard (UK). Our results show that at least two shell taxa were used and we hypothesise that these were sourced locally.

Thesis (MSc)--Stellenbosch University, 2001. / ENGLISH ABSTRACT: Runoff is generally regarded as one of the most important routes of nonpoint source pesticide pollution in agricultural surface waters. Of major concern is the fact that low, sub-lethal levels of pesticide exposure are responsible for negative ecotoxicological effects, stressing the need for methods capable of identifying problem areas where populations could be at risk. Predicted average losses of three pesticides in tributaries of nine sub-catchments of the Lourens River were calculated through use of a GIS-based runoff model. There was a significant (p < 0.005) positive correlation between the predicted average loss and mean measured concentrations of the insecticides both in water and suspended sediments (R2 between 0.75 and 0.9), indicating that the model could serve as a powerful tool for the risk assessment and management of surface waters in South African orchard areas. Based on field relevant exposure scenanos, the potential effects of azinphos-methyl on macroinvertebrate communities were evaluated in a combined microcosm and field approach. Microcosms were contaminated for 1 h with AZP (control, 0.2; 1,5and 20 ug/L; three replicates each) and acute effects on survival were evaluated 6 days after exposure. The sensitivity or tolerance of 12 core taxa was determined based on their response to the exposure scenarios and compared to field tolerance/sensitivity as was established by a field investigation at a control and contaminated site of the Lourens River. The sensitivity/tolerance of ten of the 12 taxa corresponded to that which was found in the field. Thus microcosm studies employing a field relevant design can be successfully linked to field studies and indicate that transient pesticide contamination affects the aquatic communities of the Lourens River. / AFRIKAANSE OPSOMMING Afloop word oor die algemeen beskou as een van die belangrikste roetes van niepuntbron pestisiedbesoedeling in landbou oppervlakwaters. Die feit dat lae, sub-letale vlakke van pestisiedblootstelling negatiewe ektoksikologiese gevolge kan hê, is van groot belang. Dit beklemtoon die behoefte aan metodes om probleemgebiede te kan identifiseer waar bevolkings aan risiko onderhewig is. 'n GIS-gebaseerde afloopmodel is gebruik om die gemidddelde verlies van drie pestisiede in die sytakke van nege sub-opvangsgebiede van die Lourensrivier te voorspel. Daar was 'n beduidende (p < 0.005) positiewe korrelasie tussen die voorspelde gemiddelde verlies en gemete konsentrasies van insektisiede in beide die water en sediment (R2 between 0.75 and 0.9) fases, wat aandui dat die model as 'n kragtige hulpmiddel vir risikobestuur van oppervlakwaters in Suid Afrikaanse boord-gebiede kan dien. Die potensiële gevolge van azinfos-rnetiel (AZP) op makroinvertebraat gemeenskappe is deur middel van 'n gekombineerde mikrokosmos (wat op veldrelevante blootstellings gebaseer is) en veldbenadering bepaal. Mikrokosmosse is vir 1 h met AZP gekontamineer (kontrole; 1; 0.2; 1; 5 en 20 ~g1L; drie replikate elk), en die akute gevolge op oorlewing is ge-evalueer na ses dae van blootstelling. Die sensitiwiteit of toleransie van 12 sleutel taksa is deur middel van hulle respons op die blootstellingsreeks bepaal, en met hulle veldtoleransie/sensitiwiteit vergelyk wat in 'n veldstudie by 'n kontrole- en gekontamineerde gebied in die Lourensrivier bepaal is. Die sensitiwiteit/toleransie van 10 van die 12 taksa in die mikrokosmos eksperimente het ooreengestem met die wat in die veld gevind is. Mikrokosmosstudies wat op 'n veldrelevante ontwerp gebaseer is, kan dus suksesvol aan veldstudies gekoppel word, en dui aan dat oorgedraagde pestisiedkontaminasie die akwatiese gemeenskap van die Lourensrivier beinvloed.

Thesis (PhD (Botany and Zoology))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The use of organophosphate pesticides is still an integral part of commercial farming activities and these substances have been implicated as a major source of environmental contamination in South Africa. Evidence exists that many non target animals in and around agricultural areas are at risk of being affected due to the mobile nature of pesticides and the intermittent nature of pesticide application. The extent to which non-target animals are affected by exposure to two organophosphates (azinphos-methyl and chlorpyrifos) was investigated through monitoring selected biomarker responses and life cycle effects under laboratory conditions in two selected test species. A representative species from both the aquatic and terrestrial environment was used as these two compartments of the environment are inevitably linked due to the mobility of pesticides from the area of application to surrounding areas. The earthworm Eisenia fetida was used as test organism in the terrestrial environment while the fish Oreochromis mossambicus served as representative of the aquatic environment. Juvenile life stages of both species were subjected to standard acute toxicity tests which showed that for both species, juvenile life stages were more sensitive to both pesticides than adults. It was also illustrated that azinphos-methyl is more toxic than chlorpyrifos to both species. Both test species were also subjected to an intermittent exposure regime in order to assess the effects of repeated pesticide application on biomarker, life-cycle and behaviour responses. The results indicated that for similar exposure regimes, azinphos-methyl was more toxic to E. fetida than chlorpyrifos and detrimentally affected all endpoints investigated. The present study suggests that exposure concentration may have a more pronounced effect in inducing a toxic response than exposure interval, irrespective of the pesticide used. In addition to this, E. fetida was unable to avoid the presence of these pesticides in soil, even at concentrations as high as 50% of the LC50 value, indicating that the presence of pesticides in the soil pose a realistic threat to earthworms and other soil dwelling organisms. Biomarker responses, morphological effects and feeding behaviour was assessed for O. mossambicus and similar to the terrestrial toxicity experiments, there was evidence to suggest that in the case of an intermittent exposure scenario, azinphos-methyl was more hazardous than chlorpyrifos to this species. For the majority of endpoints that were investigated, it appeared that exposure interval played a more important role in inducing an effect than exposure concentration. At a shorter exposure interval, the majority of endpoints showed no difference between higher and lower exposure concentrations, while at a longer exposure interval the effects of exposure concentration became evident. In addition, feeding behaviour was affected by pesticide exposure in a dose-dependent manner. The present study yielded important results that improve the understanding of biological impacts of pesticide pollution on the environment. This can aid in optimising farming practices such as pesticide application not only in terms of eradicating the pest organisms, but also in terms of mitigating the environmental effects associated with large-scale pesticide use, thereby ensuring sustained biodiversity in these areas. / AFRIKAANSE OPSOMMING: Die gebruik van organofosfaat plaagdoders is ‘n integrale deel van kommersiële landbou aktiwiteite maar hierdie middels is ook ‘n prominente bron van omgewingsbesoedeling in Suid-Afrika. Daar is bewys dat verskeie nie-teiken diere in en om landbouareas geaffekteer word weens die nie-statiese aard van plaagdoders in die omgewing, sowel as die herhalende aard van plaagdodertoediening. Die graad waartoe nie-teiken diere geaffekteer word deur die plaagdoders azinphos-metiel en chlorpyrifos is ondersoek deur die monitering van verskeie biomerkerresponse en lewenssiklus-effekte in geselekteerde toetsspesies binne ‘n beheerde laboratoriumomgewing. ‘n Verteenwoordigende spesie van beide die akwatiese en die terrestriële omgewing is gebruik aangesien hierdie twee dele van die omgewing onlosmaaklik verbind is weens die beweging van plaagdoders vanaf die area van toediening na omringende areas. Die erdwurm Eisenia fetida is gekies as toetsorganisme vir die terrestriële omgewing en die varswatervis Oreochromis mossambicus het gedien as verteenwoordigende spesie vir die akwatiese omgewing. Onvolwasse diere van beide spesies is onderwerp aan standaard akute toksisiteitstoetse en daar is gevind dat, vir beide spesies, onvolwasse diere meer sensitief vir die betrokke plaagdoders is as volwasse diere. Dit is ook gevind dat azinphosmetiel giftiger is as chlorpyrifos vir beide spesies. Beide toetsspesies is ook onderwerp aan ‘n chroniese blootstellingsregime om die effek van herhaalde plaagdodertoediening op biomerker-, lewenssiklus- en gedragsresponse te ondersoek. Die resultate van die herhaalde blootstelling het aangedui dat vir soortgelyke blootstellingsregimes, azinphos-metiel giftiger is as chlorpyrifos vir E. fetida en dat beide middels alle eindpunte wat ondersoek is, nadelig affekteer. Die huidige studie toon ook bewyse dat blootstellingskonsentrasie ‘n meer prominente effek as blootstellingsinterval kan hê in die teweegbringing van ‘n toksiese respons. Verder was E. fetida nie in staat om die teenwoordigheid van die plaagdoders in grond te vermy nie, self nie by konsentrasies so hoog as 50% van die LC50 waarde nie. Laasgenoemde resultaat dui dus aan dat die aanwesigheid van plaagdoders in die grondomgewing ‘n realisitese bedreiging inhou vir erdwurms en ander grondorganismes. Soortgelyk aan die terrestriële toksisiteitseksperimente, was daar getuienis vir die verhoogde toksisiteit van azinphos-metiel relatief tot chlorpyrifos vir O. mossambicus. Dit blyk dat blootstellingsinterval ‘n meer prominente rol as blootstellingskonsentrasie speel in die teweegbringing van effekte vir die meerderheid van die eindpunte wat ondersoek is. In die geval van ‘n korter blootstellingsinterval het die meerderheid van eindpunte wat ondersoek is geen verskille getoon tussen ‘n hoër en ‘n laer konsentrasie nie, terwyl met ‘n langer blootstellingsinterval daar ‘n aanduiding was dat blootstellingskonsentrasie ‘n meer prominente rol gespeel het. Verder is gevind dat voedingsgedrag in O. mossambicus geaffekteer is op ‘n konsentrasie verwante manier. Die huidige studie toon resultate wat ‘n belangrike bydrae kan lewer tot die begrip van die biologiese impakte van organofosfaat plaagdoders op die omgewing. Die resultate kan gebruik word vir die optimisering van boerderypraktyke soos plaagdodertoediening, sodat laasgenoemde effektief is vir die beheer van pes-organismes, maar ook die impakte van grootskaalse plaagdodertoediening kan minimaliseer en sodoende die biodiversiteit binne hierdie areas sal beskerm.

Η παρούσα μελέτη στοχεύει στη διερεύνηση των τοξικών επιπτώσεων των στραγγισμάτων που δημιουργούνται σε χώρους υγειονομικής ταφής απορριμμάτων (ΧΥΤΑ) σε υδρόβιους οργανισμούς, όπως τα ανόστρακα καρκινοειδή Thamnocephalus platyurus και Artemia franciscana, το τροχόζωο Brachionus plicatilis, το μικροφύκος Dunaliella tertiolecta και το δίθυρο μαλάκιο Mytilus galloprovincialis, καθώς και τη διερεύνηση των παραμέτρων που θα μπορούσαν να επηρεάσουν την εν δυνάμει τοξικότητά τους. Η μελέτη στραγγισμάτων που συλλέχθηκαν από τον ΧΥΤΑ Αιγείρας (ν. Αχαΐας) κατά τη διάρκεια του έτους 2011, έδειξε σημαντικές ποιοτικές και ποσοτικές εποχιακές διαφορές στην εν δυνάμει τοξικότητα των στραγγισμάτων στους οργανισμούς που ελέγχθηκαν, με τις σημαντικότερες τοξικές επιπτώσεις να εμφανίζονται στα δείγματα που συλλέχθηκαν κατά τη διάρκεια άνυδρων περιόδων, όπως η περίοδος μεταξύ Οκτωβρίου και Δεκεμβρίου. Παρόμοια, έκθεση μυδιών σε δείγμα στραγγίσματος που συλλέχθηκε κατά τη διάρκεια της παραπάνω περιόδου (Νοέμβριος 2011) έδειξε σημαντική αύξηση του ποσοστού θνησιμότητας των ατόμων, σε συγκεντρώσεις μεγαλύτερες από 0.5% v/v, ενώ σε μικρότερες συγκεντρώσεις (0.01 και 0.1% v/v) εμφανίστηκαν σημαντικές κυτταροτοξικές, νευροτοξικές και γενοτοξικές επιπτώσεις, καθώς και φαινόμενα οξειδωτικής καταπόνησης (oxidative stress). Τα αποτελέσματα της παρούσας εργασίας καταδεικνύουν την τοξικότητα των σταγγισμάτων σε υδρόβιους οργανισμούς, η οποία μπορεί επιπλέον να εκτιμηθεί μέσω της ανάλυσης επιλεγμένων παραμέτρων όπως η αγωγιμότητα (Cond), τα παράγωγα του αζώτου (NO3−, και NH4–N), ο λόγος BOD5/NH4–N και οι φαινόλες (T-PH). / The present study investigates seasonal variations of leachate composition and its toxic potency on different species, such as the brine shrimp Artemia franciscana (formerly Artemia salina), the fairy shrimp Thamnocephalus platyurus, the estuarine rotifer Brachionus plicatilis and the microalgal flagellate Dunaliella tertiolecta, as well as its ability to induce lethal and pre-pathological alterations in organisms bioindicators, such as the mussel Mytilus galloprovincialis. In specific, leachate regularly collected from the municipal landfill site of Aigeira (Peloponissos, Greece) during the year 2011, showed significant alterations of almost all its physicochemical parameters, as well as its toxic potency, with time. Samples collected during the dry season (October until December) proved to be more toxic than samples from other sample dates/periods. Further analysis showed significant increase of mortality among mussels exposed to leachate collected during that period (November 2011) (96h LC50 = 0.526%, v/v), while mussels exposed to sub-lethal concentrations (0.01 και 0.1% v/v) showed increased cytotoxic, neurotoxic, genotoxic and oxidative effects. The current study revealed for the first time that the estimation of a battery of leachate physicochemical parameters, such as Cond, TDS, NH4–N, T-PH and the respective BOD5/NH4–N ratio, could be used as a low-cost effective tool in order to estimate leachate strength and toxicity, at least in the case of semi-arid areas, such as the most of the Mediterranean countries.

M.Sc. / The increase in industrialisation, mining and agricultural activity along rivers could have a detrimental effect on aquatic environments unless the dangers of pollutants are not taken notice of. Metal ions and industrial effluent have become a source of pollution in the watercourses of South Africa. Pollutants generally have negative effects on the physiology of aquatic biota in polluted waters. The effects of copper and industrial effluent by the exposure of the clawed toad, Xenopus laevis and Tilapia sparrmanii are presented in this study. An experimental static-renewal system with an exposure time of 96 hours was followed at 25±1°C. After copper and effluent exposure, several physiological changes occurred in the two aquatic organisms. The sublethal effects that occurred include changes in hatching, survival, behaviour, growth impairment and developmental limitations. The results of the present study suggest that lethal endpoints can be used as indicators in detecting and evaluating the effects of aquatic pollution, caused by copper and effluent. Individual variation, however, could hamper the conclusions made but the study of aquatic organisms is of practical importance when conducting experimental studies in a laboratory and does not have the same impact as during field studies. Apart from the exposure to sublethal concentrations of copper and effluent, computational derivations of LC50, NOEC values and 95% confidence limits were made. The obtained concentrations were used as assumptions that pollutants should not exceed for the protection of aquatic life. Statistically different differences were found between the chosen derived variables of control and experimental organisms. The advantages of FETAX solution over borehole water can be attributed to the bioavailability of pollutants, which appears to be much less in those solutions. The predicted NOEC values provide some information regarding the concentrations at which no effects will be observed and the Target Water Quality Ranges (TWGR) for water were used to determine if the diluent was correct.

CAPES / A água é fundamental para o equilíbrio ecológico e manutenção da vida, entretanto perturbações de diferentes magnitudes têm alterado seriamente sua qualidade. Nesse sentido, diversas metodologias de análise buscam mensurar o seu grau de contaminação, utilizando avaliação de parâmetros físicos, químicos e biológicos. Reservatórios podem ser classificados como ecossistemas semi-lóticos originados a partir do represamento de rios e a distribuição de organismos nesse corpo hídrico é influenciada pelas características físicas, químicas e interações biológicas e ecológicas. O reservatório do rio Verde localiza-se na divisa dos municípios de Campo Largo e Araucária, Estado do Paraná. O presente estudo teve por finalidade a caracterização física e química de água e sedimentos, assim como avaliação da macrofauna nectônica e bentônica em quatro pontos do reservatório ao longo das quatro estações climáticas entre os anos de 2013 e 2014. Quanto aos parâmetros físicos e químicos, todos à exceção da matéria orgânica encontram-se dentro dos valores preconizados por legislações pertinentes. A macrofauna do reservatório mostrou-se rica e diversificada. Ao total foram coligidos 1880organismos, sendo 938 exclusivamente no sedimento. Ao longo do período amostral foi registrada a presença de táxons bioindicadores, assim como organismos de importância médica e ecológica. De acordo com o teste de regressão linear múltipla, os fatores significativos para a distribuição da comunidade bentônica foram pH, temperatura da água, oxigênio dissolvido, saturação de oxigênio dissolvido, condutividade, material em suspensão (total, orgânico e inorgânico), turbidez, clorofila-a, nitrito, nitrato, matéria orgânica, umidade, fósforo e nitrogênio totais e as frações granulométricas areia média, areia fina e silte/argila. Já para a composição de guildas tróficas, foram registrados cinco grupos: coletores, predadores, raspadores, filtradores e fragmentadores. A partir do teste de regressão linear não-paramétrica, foram consideradas significativas as variáveis turbidez, profundidade e as frações granulométricas. O resultado dos índices de qualidade BMWP' e Diversidade de Shannon-Wiener sugere poluição moderada, resultado que complementa o obtido exclusivamente pelas análises físicas e químicas, corroborando a importância da inclusão da avaliação das comunidades aquáticas e bentônicas em programas de monitoramento ambiental. / Water is essential to the ecological balance and maintenance of life, however disturbances of different magnitudes have seriously affects their quality. In this sense, various analysis methodologies seek to measure the rate of contamination using evaluation of physical, chemical and biological parameters. Reservoirs can be classified as semi-lotic ecosystems originated from the damming of rivers and the distribution of organisms in this water body is influenced by physical, chemical and biological/ecological interactions. The Verde river reservoir is located on the borderland of the cities of Campo Largo and Araucaria, Parana State. The present study aimed the physical and chemical characterization of water and sediment, as well the evaluation of aquatic and benthic macroinvertebrates in four sample points along four seasons in the reservoir between the years 2013 and 2014. Relative to the physical and chemical parameters, all except organic matter are within the recommended values for relevant legislation. The macrofauna of the reservoir proved to be rich and diverse. A total of 1880 organisms were collected, with only 938 in the sediment. Over the sample period was recorded the presence of bioindicators taxa as well organisms of medical and ecological importance. According to the multiple linear regression model, the significant factors for the distribution of the benthic community were pH, water temperature, dissolved oxygen, dissolved oxygen saturation, conductivity, suspended matter (total, organic and inorganic), turbidity, chlorophyll- a, nitrite, nitrate, organic matter, humidity, phosphorus and total nitrogen and grain size medium sand fractions, fine sand and silt/clay. For the composition of trophic guilds, were registered five groups: collectors, predators, scrapers, slicers, filterers and shredders. From the non-parametric linear regression test, were considered significant the variables turbidity, depth and granulometric fractions. The result of the quality index BMWP ' and Shannon -Wiener Diversity suggests moderate pollution, a result that complements that obtained exclusively by physical and chemical analysis, corroborating the importance of including the assessment of aquatic and benthic communities in environmental monitoring programs.

Made available in DSpace on 2016-06-02T19:29:17Z (GMT). No. of bitstreams: 1 2445.pdf: 4928937 bytes, checksum: 329cdf8352a20c310390781ed4cb098d (MD5) Previous issue date: 2009-04-06 / Universidade Federal de Sao Carlos / The present research is a qualitative-quantitative study, involving participative-actionresearch and descriptive procedures, achieved through analysis of empirical knowledge and field (practical) research. The object of the research is the aquatic bio-indicator organisms, mainly fish, related to Environmental Education. It was intended to demonstrate that their identification is an important collaborating strategy in the construction of ecological awareness of the subjects aimed in this study, students from 5th to 8th year of grade school in private schools in the City of São Carlos, SP. The specific methodological procedures used were environmental study activities; lectures; technical visits, having one of them happened in the presence of the subjects (excursion through the course of Córrego do Gregório); material sampling; laboratory identification. The results obtained in terms of achieving the intended objectives are lists of reminiscent bio-indicator organisms in Córrego do Gregório and Ribeirões Feijão and Monjolinho, which suffer human antropic influence, emphasizing those which are good indicators of environmental quality. Through interfaces with Environmental Education, the study has motivated children to the construction of the ecological awareness and socio-environmental a responsibility, having contributed to the construction of concepts and values which are interconnected to the environmental area under the light of ethics and solidarity. / A presente pesquisa trata-se de um estudo de caso de natureza quali-quantitativa, envolvendo pesquisa-ação-participativa e procedimentos descritivos, realizado mediante análise de conhecimentos empíricos e pesquisa de campo. O objeto da pesquisa são os organismos aquáticos bioindicadores da qualidade ambiental, principalmente peixes, relacionados com a Educação Ambiental. Pretendeu-se demonstrar que sua identificação é importante estratégia colaboradora na construção da consciência ecológica dos sujeitos alvo desta pesquisa, os alunos de 5ª a 8ª séries do ensino fundamental em escola da rede particular de ensino da cidade de São Carlos/SP. Os procedimentos metodológicos e técnico-operacionais utilizados foram atividades de estudo do meio; palestras; visitas técnicas, sendo uma delas realizada em presença dos sujeitos (excursão pelo percurso do Córrego do Gregório); coleta de material; identificação em laboratório. Os resultados conseguidos em termos de atingimento dos objetivos propostos são listas de organismos bioindicadores remanescentes no Córrego do Gregório e nos Ribeirões Feijão e Monjolinho, mananciais que sofrem influência antrópica municipal, destacando aquelas que são boas indicadoras da qualidade ambiental. Em interface com a Educação Ambiental, motivou as crianças para a construção da consciência ecológica e a responsabilidade sócio-ambiental, contribuindo para a construção de conceitos e de valores interligados na área ambiental à luz da ética e da solidariedade.

Made available in DSpace on 2014-10-09T12:42:12Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:05:28Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Made available in DSpace on 2014-10-09T12:42:12Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:05:28Z (GMT). No. of bitstreams: 0 / Estudos recentes têm identificado a presença de diversos poluentes emergentes em ambientes aquáticos. A ocorrência em diferentes matrizes ambientais tem sido continuamente relatada, o que evidencia a necessidade de estudos de toxicidade. O DEET (N,N-dietil-meta-toluamida) é o princípio ativo mais utilizado em repelentes de insetos e está presente em diversas formulações comercialmente disponíveis. Além dos poluentes químicos, os organismos aquáticos estão sujeitos à exposição da radiação ionizante proveniente de fontes naturais ou em proximidades de instalações de usinas nucleares. O presente estudo avaliou a toxicidade do DEET em organismos irradiados e não irradiados com radiação gama de 60Co, e os efeitos que a radiação causa sob os lisossomos de hemócitos do mexilhão Perna perna. Para isso, foram realizados ensaios de toxicidade aguda para identificar a concentração de DEET e a dose de radiação gama passíveis de causar mortalidade, e posteriormente ensaios de citotoxicidade avaliando a estabilidade da membrana lisossômica em organismos expostos ao DEET e radiação ionizante. De acordo com os resultados obtidos nos ensaios de toxicidade aguda, a concentração de DEET que causa mortalidade em 50% dos organismos expostos (CL50) é de 114,27 mg L-1, e a dose de radiação que causa mortalidade (DL50) é de 1068 Gy. Nos os ensaios de citotoxicidade obteve-se a concentração de efeito não observado (CENO) para organismos irradiados e não irradiados de 0,0001 mg L-1 e a concentração de efeito observado (CEO) em concentrações acima desta. A CI25(72h) para organismos não irradiados foi de 0,0003 mg L-1 e a CI50(72h) foi de 0,0008 mg L-1 para organismos irradiados e não irradiados. Apesar das concentrações de efeito encontradas no presente estudo terem sido mais altas que as ambientais, estão na mesma ordem de grandeza e também deve-se levar em consideração os possíveis efeitos sinérgicos do DEET com outros contaminantes presentes em ambiente aquático. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2016-11-11T16:56:25Z No. of bitstreams: 0 / Made available in DSpace on 2016-11-11T16:56:25Z (GMT). No. of bitstreams: 0 / As evidências da contaminação das águas por resíduos de medicamentos e seus subprodutos levou esse grupo de resíduos a compor a lista de poluentes orgânicos emergentes, como consequência da expansão do uso de medicamentos, como o antidepressivo cloridrato de fluoxetina e o anti-inflamatório diclofenaco. Diversos Processos Oxidativos Avançados vêm sendo aplicados para a degradação destes compostos. Dentre eles, o processo de irradiação com feixe elétrons obteve bons resultados na remoção de toxicidade e degradação de fármacos. O presente estudo consistiu em aplicar radiação ionizante como uma possível tecnologia para degradar os fármacos em águas. A irradiação de solução aquosa contendo os fármacos foi aplicada usando acelerador de elétrons, cuja eficiência foi discutida mediante análises químicas (Cromatografia Líquida Ultra Rápida e Carbono Orgânico Total (COT)), ecotoxicológicas (ensaios de toxicidade com Vibrio fischeri e Daphnia similis) e biológicas (Ensaios Respirométricos). Os resultados de COT indicaram mineralização não significativa dos compostos, mesmo sendo observada degradação máxima de 99,9% para o diclofenaco e 55% para o cloridrato de fluoxetina na mistura (1:1) em 5.0 kGy. Foi observada toxicidade aguda dos fármacos, sendo mais acentuada para a fluoxetina, seguido do diclofenaco e, finalmente, da mistura para V. fischeri. Quando D. similis foram empregadas nessa avaliação, a ordem de toxicidade foi de fluoxetina, a mistura de ambos os medicamentos e do diclofenaco. Além disso, foi observada remoção de toxicidade nas amostras irradiadas em todas as doses aplicadas para a bactéria V. fischeri, com maior eficiência de remoção de toxicidade de 55%, em 5 kGy, na mistura dos dois fármacos. Para a D. similis, foi observada remoção significativa de toxicidade da mistura apenas na dose 2,5 kGy. Os ensaios respiroétricos não indicaram biodegradabilidade após o tratamento. / Dissertação (Mestrado em Tecnologia Nuclear) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP