In recent years, a growing number of human pharmaceuticals have been detected in the aquatic environment, generally at low concentrations (sub-ng/L to low μg/L). These compounds are characterised by highly specific mechanisms of action, high potency and prolonged activity in order to minimise dosing requirements and potential toxicity in patients. Among the various classes of pharmaceuticals, steroids and anti-steroids are widely used, as shown by the analysis of their clinical use carried out at the beginning of this Ph.D. project. Although the amounts used are much lower than the amounts of some other pharmaceuticals (e.g. analgesics), their ability to affect important physiological processes in fish (e.g. reproduction) at very low concentrations (ng/L) suggest that this class of compounds should represent a high priority for ecotoxicological research. In particular, this Ph.D. project addressed the question of whether or not dutasteride, a human pharmaceutical mainly used to treat benign prostatic hyperplasia, may cause adverse effects in the teleost fathead minnow (Pimephales promelas) by inhibiting the activity of both isoforms of 5α-reductase (5αR), the enzyme which convert testosterone into dihydrotestosterone (DHT). The theoretical framework used to guide the design of the experimental studies was based on the combination of several conceptual approaches, including the study of the evolutionary degree of conservation and functionality of the drug target in non-target species, and the cross-species extrapolation of pharmacological and toxicological information generated during pre-clinical and clinical studies in mammals during drug development. The results obtained during the first phase of this Ph.D. project strongly suggested that DHT has a physiological role in the fathead minnow. In fact, 5αRs are evolutionary conserved in this species, 5αRs genes are expressed in tissues such as the testis, and DHT circulates in fathead minnow plasma at concentrations similar to those detected in humans. These findings represented the rationale for testing the effects of dutasteride in the fathead minnow. Dutasteride caused significant adverse effects in all the in vivo studies performed in order to evaluate its potential toxicity on fish, including early life stage and short term reproduction studies, and all the tested life stages were sensitive to the inhibition of 5αRs activity; however, none of the observed adverse effects occurred at concentrations of exposure lower than 32 μg/L (measured concentration). The results also showed that female fish are highly sensitive to disruption of the androgenic pathways, highlighting their utility for the evaluation of potential adverse effects caused by anti-androgens on fish. In conclusion, the results presented in this Thesis suggest that, at present, the potential presence of dutasteride in the environment does not represent a risk to wild fish populations, due to the high concentrations required to elict significant adverse effect (LOEC = 32 μg/L) and the low volume of drug prescribed every year (5.07 kg in UK in 2006). However, the high bioaccumulation factor of dutasteride suggest that further studies should be conducted to elucidate the role played by the bioaccumulation process in the toxicity responses observed in fish.

Made available in DSpace on 2017-07-10T18:01:55Z (GMT). No. of bitstreams: 1 Francielli De Bona Galvan.pdf: 2787047 bytes, checksum: dcf6ada2d9e9c708b2dadc574098b58b (MD5) Previous issue date: 2015-07-28 / Fundação Araucária / The removal of contaminants in aquatic environments must be performed by means of suitable treatment processes to ensure that water resources are not compromised because of this contamination. It is found that processes employing light have shown good results in the degradation of emergent contaminants. In this sense, this study aimed to determine the best photodegradation conditions of cephalexin antibiotic (CFX) in aqueous solution, using Advanced Oxidative Processes - AOP (UV, UV / H2O2, UV / H2O2 / TiO2 and UV / H2O2 / ZnO). In photocatalysis tests, the variables were organized in an experimental design to verify the influence of each variable in the degradation process, and the experimental results were evaluated using the statistical software Statistica®. It was observed from the analysis of the results that the best conditions for the degradations process were [H2O2] = 1000 mg L-1 and [TiO2] = 50 mg L-1 at pH 4 after two hours of irradiation. / A remoção de contaminantes nos ambientes aquáticos deve ser realizada por meio de processos de tratamento adequados, para garantir que os recursos hídricos não sejam comprometidos em virtude desta contaminação. Verifica-se que os processos que empregam luz têm apresentado bons resultados na degradação de poluentes emergentes. Neste sentido, o presente trabalho tem como objetivo determinar as melhores condições de fotodegradação do antibiótico cefalexina (CFX) em solução aquosa, empregando-se Processos Oxidativos Avançados - POA (UV, UV/H2O2, UV/H2O2/TiO2 e UV/H2O2/ZnO). Os experimentos foram acompanhados por espectrofotometria na região UV-VIS. Nos ensaios de fotocatálise, as variáveis foram organizadas em um planejamento experimental para verificar a influência de cada variável no processo de degradação, e os resultados experimentais foram avaliados empregando-se o software estatístico Statistica®. Observou-se pela análise dos resultados que as melhores condições para o processo de fotodegradação foram [H2O2] = 1000 mg L-1 e [TiO2] = 50 mg L-1 em pH 4.

This diploma thesis deals with the question of whether do public subsidies cause wasteful use of pharmaceuticals, and if so then to what extent. The hypothesis is tested on the Czech republic data for the years 2005-2012. The biggest contributions are defining the health system as an intra-temporal problem, which tells us that lower values of discount rate implies higher level of wasteful use. I express the environmental issues, which are caused by unprofessional pharmaceutical disposal. You can find the price (-0,11), the income (-0,2) and the cross-price (-0,14) elasticity of demand for pharmaceuticals in the empirical part. These estimates are obtained with the help of the Kuhn-Tucker method. Using the 2OLS method Model 2 comes with the major findings. With 10% increase of public subsidies, consumers tend to waste 13,2% more pharmaceuticals.