Orientador: Marcelo de Freitas Lima / Coorientador: Lidia Maria de Almeida Plicas / Banca: Josefredo Rodriguez Pliego Junior / Banca: Luis Octávio Regasini / Resumo: Esse trabalho teve como objetivo o estudo da degradação de um organofosforado modelo, o 4-nitrofenil fosfato de dietila (paraoxona), por meio de reações fotoquímicas e químicas. O armazenamento ilegal, sua alta toxicidade e os métodos de degradação utilizados na eliminação de pesticidas levaram à necessidade de encontrar métodos de degradação alternativos para os mesmos. Com isso, no estudo fotoquímico as reações fotossensitizadas tipo II foram empregadas e a espécie reativa, oxigênio singlete, foi produzida a fim de degradar a paraoxona. Em paralelo aos experimentos, o estudo químico-computacional foi realizado a fim de fornecer subsídios para uma possível explicação sobre a reatividade das espécies analisadas. Por meio dos resultados dos cálculos realizados foi possível analisar os orbitais de fronteira, os quais forneceram informações preciosas sobre a inércia da paraoxona frente ao oxigênio singlete, sugerindo que efeitos indutivos e de ressonância no anel têm papel importante no mecanismo de reação. Já nos estudos químicos utilizou-se a hidroxilamina, um nucleófilo alfa, como meio de degradação. O método mostrou-se eficiente e com alta dependência do pH do meio reacional, onde os melhores resultados para a reatividade do nucleófilos foram encontrados na faixa de pH 6,27 a 11,49. Os estudos com diferentes concentrações de nucleófilo indicam que não há participação direta da água na etapa lenta do mecanismo de reação. A termodinâmica do processo reacional aponta com muita clareza para um mecanismo associativo, provavelmente do tipo SN2(P). Parâmetros de correlação entre pKa dos nucleófilos e velocidade mostram que a paraoxona é insensível à basicidade do nucleófilo, como atestado pelo valor de Brownsted igual a 0,02 para nucleófilos comuns. Contudo fica evidente o efeito alfa apresentado pela hidroxilamina e a metil hidroxilamina. Na presença de hidroxilamina a velocidade de... / Abstract: This work aimed to study the degradation of an organophosphorus model, the 4- nitrophenyl diethyl phosphate (paraoxon) through photochemical and chemical reactions. The illegal storing, their high toxicity and degradation methods used in the elimination of pesticides have led to the need to find alternative methods for the degradation thereof. Thus, the study photochemical reactions photosensitized type II were employed and the reactive species, singlet oxygen was produced to degrade paraoxon. In parallel to the experiments, the chemical and computational study was conducted to provide information for a possible explanation of the reactivity of the species analyzed. Through the results of calculations performed was possible to analyze the orbital border, which provided valuable information on the inertia of paraoxon against singlet oxygen, suggesting that inductive and resonance effects in the ring have an important role in the reaction mechanism. Already in chemical studies we used hydroxylamine, a nucleophile alpha like through degradation. The method was efficient and high pH dependence of the reaction medium, where the best results for the reactivity of nucleophiles were found in the pH range from 6.27 to 11.49. Studies with different concentrations of nucleophile does not indicate the direct participation of water in the slow step of the reaction mechanism. The thermodynamics of the reaction process very clearly points to an associative mechanism, probably the type SN2 (P). Correlation parameters between pKa of nucleophiles and speed show that paraoxon is insensitive to basicity of the nucleophile, as attested by Brownsted value equal to 0.02 for common nucleophiles. However it is evident the alpha effect presented by hydroxylamine and hydroxylamine methyl. In the presence of hydroxylamine degradation rates increased about 840 times comparing with its spontaneous hydrolysis / Mestre

Orientador: Classius de Oliveira / Banca: Lia Raquel de Souza Santos / Banca: Fernanda Cristina Alcantara dos Santos / Banca: Alexandre Ninhaus Silveira / Banca: Selma Maria Almeida Santos / Resumo: A reprodução pode ser descrita como o conjunto de atributos fisiológ icos, morfológicos e comportamentais que permitem o sucesso de uma espécie através da máxima descendência sob condições ambientais específicas. Em anfíbios, além de sujeito a um controle hormonal, e considerando o aporte genético, o ciclo reprodutivo é também influenciado por fatores ambientais que determinam o ciclo ga metogênico ao longo de um ano. O presente trabalho teve como objetivo estimar a di versidade genética em duas populações de P. cuvieri pertencentes aos biomas de Mata Atlânti ca e do Cerrado com o marcador molecular ISSR ( Inter Simple Sequence Repeats ). Além disso, foi caracte rizado o ciclo reprodutivo destas populações, relacionando as variações morfológicas gonadais com os fatores climáticos precipitação, temperatura, umidade relativa do ar e velocidade do vento, através de uma Análise de Correspondência Canônica, bem como relacionar a quantidade de pigmentos presente nos testículos com os períodos pré-reprodutivo, reprodutivo e regenerativo através de ANOVA. Ta mbém se analisou em indivíduos de Eupemphix nattereri a relação entre a espermiogênese e a qua ntidade de pigmentação testicular. As populações de P. cuvieri pertencentes aos dois biomas re velaram índice de diferenciação genética (FST ) > 0.288, o que mostra que es tas duas populações são altamente diferenciadas geneticamente. Foram caracter izados 7 tipos celu lares representando o epitélio germinativo. A variância total ao longo do ciclo reprodutivo foi de 23 %, com os dois primeiros eixos responsáveis, respectivamente, por 68,7% e 10,2% da variância total acumulada na média ponderada dos tipos celula res com relação às 4 variáveis ambientais analisadas. O teste de permutação de Monte Carlo indicou que os tipos celulares e a... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Reproduction can be described as the set of physiological, mo rphological, and behavioural attributes that allow for the success of a species through maximum offspring under specific environmental conditions. In amphibians, as well as being under hormonal control, and in view of their genetic constitution, the reproductive cycle is also influenced by environmental factors that determine the ga metogenetic cycle throughout the year. The aim of this study was to characterize the reproductive cycle of Physalaemus cuvieri in populations from the Mata Atlântica region and the Ce rrado region, comparing the morphological gonad variations to the climatic factors of precipita tion, temperature, relative humidity and wind speed, through a Ca nonical Correspondence Analysis, as well as comparing the quantity of pigments presen t in the testis with the pre-reproductive, reproductive and regenerative periods usi ng the ANOVA, and estimating the genetic diversity between the populations of the two biomes with genetic markers ISSR ( Inter Simple Sequence Repeats). The relationship between spermatogenesis and the quantity of testicular pigmentation in individuals of Eupemphix nattereri has also been analyzed... (Complete abstract click electronic access below) / Doutor

To date, limited research has been conducted on the effects of cytotoxic drugs on aquatic species. Three of these species, a single celled plant, an invertebrate and a fish, were exposed to six cytotoxic drugs, both singly and as simple mixtures. A range of endpoints were assessed, including growth inhibition in algae, immobilisation in daphnia and the impact on organ size and the expression of the DNA damage repair genes RAD51 and p53 in zebrafish. No effects at environmentally relevant concentrations were observed in any of the three species.

No description available.

Methylmercury (MeHg) is known predominantly as a neurotoxicant, however emerging experimental and epidemiological evidence has shown associations between MeHg exposure and the potential for increased risks of cardiovascular diseases. This thesis investigated the in vitro cytotoxic effects of MeHg in two cardiomyocyte cell lines, H9C2 rat neonatal cell line and AC16 adult human cell line. We observed significant increases in cell death at concentrations from 1 – 10 µM. ROS production and intracellular calcium concentrations increased dose-dependantly with MeHgCl exposure. Furthermore, while assessing mitochondrial function, a decline in maximal respiration at 1 µM was seen. However, these observations may in turn be a direct consequence of decreased cell numbers following exposures. Additionally, this study highlighted the differences in cellular bioenergetics which may impact how certain cells respond to contaminant stressors. The distribution of MeHg and total Hg in rat heart tissues was also examined and we observed increasing concentrations of MeHg in high and low dosed rat groups as compared to the vehicle controls. No difference was observed in Hg levels between the normal and high fat and sugar diet groups. The urinary isoprostane levels, which are indicative of systemic oxidative stress, showed significant increases in lean rats exposed to the high dose treatment. It was also observed that a high fat and sugar diet in lean and obese rats can contribute to increasing oxidative stress regardless of the level of contaminants they were dosed with. This thesis demonstrated several in vitro effects of MeHg on heart cells as well as determine the distribution of Hg levels in heart tissues and oxidative stress markers from an in vivo study.

Orientadores: Maurea Nicoletti Flynn, Gisela de Aragão Umbuzeiro / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Tecnologia / Made available in DSpace on 2018-08-26T21:07:30Z (GMT). No. of bitstreams: 1 Alegretti_Lucas_M.pdf: 2378258 bytes, checksum: db1360024f2abd7e9ffc0aedfe3f1777 (MD5) Previous issue date: 2015 / Resumo: As respostas de populações ao estresse ambiental têm sido avaliadas em relação a efeitos na taxa de crescimento da população, na capacidade suporte do meio, na densidade e viabilidade populacional. Os objetivos deste trabalho englobam a descrição da estrutura e da dinâmica de uma população natural de Parhyale hawaiensis através da confecção de tabela de vida idade-específica para obtenção de parâmetros vitais populacionais, além de fornecer recomendações metodológicas para testes de toxicidade crônica, conhecido como LTRE (Life Table Responde Experiment). A estrutura populacional, a classe etária, a evolução da densidade, a razão sexual, a curva de sobrevivência, a taxa líquida de reprodução, o tempo de geração e a taxa per capita de crescimento foram estabelecidos para uma população da região entre marés do cinturão de algas, em Poço de Anchieta, Itanhaém - SP. A estratégia de vida identificada para a espécie está associada a um padrão de dinâmica populacional consistente com o comportamento adotado por espécies costeiras em ambientes fisicamente controlados e sujeitos a frequentes perturbações, e sugerem tendências relacionadas à latitude, produtividade e previsibilidade que podem ser resumidas nas hipóteses de seleção r-K relacionadas à longevidade, maturidade e fecundidade da espécie. A abordagem experimental aqui recomendada procura delinear um experimento com período de 12 semanas com a espécie teste P. hawaiensis, com o objetivo de obter respostas a agentes estressores em nível populacional, utilizando com endpoints as estatísticas demográficas: o potencial reprodutivo (R0), a taxa intrínseca de crescimento (r) e o tempo de geração (T). Os valores guias estimados foram respectivamente R0 = 1.45 ± 1.01, r = 0.057 ± 0.169 e T = 3.510 ± 1.305 / Abstract: Population¿s responses to environmental stress have been evaluated for effects on parameters such as population growth rate, environment carrying capacity, population density and viability. The objectives of this study are to describe the structure and dynamics of a natural population of Parhyale hawaiensis by constructing age-specific life tables to obtain population vital parameters and provide methodological recommendations for chronic toxicity tests, known as LTRE (Life Table Response Experiments). The population structure, age group, temporal evolution of the density, sex ratio, survival curve, net reproductive rate, generation time and per capita growth rate were established for a population of the intertidal belt algae, in Poço de Anchieta, Itanhaém - SP. The life strategy identified for the species is associated with a pattern of population dynamics consistent with the behavior adopted by coastal species in physically controlled environments and subject to frequent disruptions, suggesting trends related to latitude, productivity and predictability summarized by rK selection related to longevity, maturity and fecundity of the species. The experimental approach recommended here seeks to outline an experiment with 12-week period with the test species P. hawaiensis, in order to get answers to stressors at the population level, using endpoints with demographic statistics: the reproductive potential (R0), the intrinsic growth rate (r) and the generation time (T). The estimated guide values were respectively R0 = 1.45 ± 1.01, r = 0.057 ± 0.169 and T = 3.510 ± 1.305 / Mestrado / Ambiente / Mestre em Tecnologia

The release of pollutants by the oil sands industry and pulp and paper mills has been an ongoing environmental concern for decades. Such toxins have been linked to declining reproductive and skeletal health in wildlife species, as they have known endocrine disrupting properties that interfere with hormones responsible for proper reproduction and bone development. As such, declining population sizes because of pollutant exposure has been correlated with altered bone health in mammals. For the purposes of environmental monitoring, the development of a biomarker of pollutant exposure would be a beneficial tool to assess pollution impact on wildlife populations. Therefore, the purpose of this research was to identify this biomarker in the American mink based on measures of their bone health. Mink from the Athabasca Oil Sands Region and an area surrounding a pulp and paper mill in Quebec were collected. From each mink, a hindlimb femur and the baculum (for males) were dissected. Bones were evaluated through a series of tests to quantify key cortical and cancellous bone structural and material properties. These included dimensional analysis, three-point bending and micro-Computed Tomography. Toxicology reports of trace element exposure levels in the minks were also provided by ECCC. Principal component analyses and correlation matrices were used to identify potential relationships between the bone metrics and trace element levels, followed by linear regression modeling. Results found that the baculum and femur structural properties were correlated with selenium, rubidium and iron concentrations, suggesting that these elements had the strongest influences on bone health for the mink studied here. This work provides the basis for future research on identifying a biomarker determinant of bone health to be used in environmental monitoring effects programs. The results here indicate that baculum bone measures are dominated by trace element effects rather than loading effects and are thus a useful bone to investigate for biomonitoring programs. This will provide a simple and reliable method for determining whether there are unsustainable levels of pollution in regions across North America. / Thesis / Master of Applied Science (MASc) / Environmental pollution in regions across Canada puts the health of communities and wildlife at risk. To better measure the impact of pollution in these regions, the implementation of a species monitoring program would benefit those communities who are at the greatest risk. Therefore, this research was aimed at developing an indicator of harmful pollution exposure in mink, an abundant species in Canada, by investigating their bone health. A group of mink from Alberta and Quebec were collected and their femur and penile bones tested for a variety of bone health measurements. In addition, information on the heavy metal levels in the mink livers were provided. The bone health measurements and heavy metal levels were then compared to look for any relationships between them. This research found that selenium, rubidium and iron had the strongest effects on bone health. The methods used have set the groundwork for using minks to monitor pollution levels across North America.

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.

Persistent, anthropogenic contaminants collectively known as endocrine-disrupting chemicals (EDCs), are considered to be potential threats to wildlife reproductive fitness (Wingfield, 2002). The modes by which EDCs act on the reproductive system, and establishment of steroid profiles in wildlife, are important areas of study. Two means of performing an endocrine snapshot profile from dolphin tissues (serum and urine) were tested on samples, comparing a novel high performance liquid chromatography method to newly-validated enzyme-linked immunoassays (ELISAs). Serum and urine samples were obtained from two marine parks, and from free-ranging dolphins in the Indian River Lagoon (IRL) and Charleston Harbor (CHS) systems. Relative binding affinities of steroids versus putative EDCs to steroid receptors were compared in dolphin reproductive tissues, obtained by the Georgia Aquarium's Dolphin Conservation Field Station (GADCFS) from strained bottlenose dolphins (four male, three female) during 2010 and 20ll.........I conclude that endocrine disruptors are tissue and receptor specific, and both legacy and emerging contaminants are of concern to dolphin stocks, particularly those facing other significant environmental stressors. / by Sharon M. Homer-Drummond. / Vita. / Thesis (Ph.D.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.

A aplicação do lodo de esgoto em sistemas florestais busca o aprimoramento da produção, favorecendo as características físicas, químicas e biológicas do solo e das plantas. Entretanto, o lodo pode conter patógenos e, elementos orgânicos e inorgânicos tóxicos, e o efeito destes contaminantes no solo e na planta ainda é pouco conhecido. Sendo assim, foi estabelecida a hipótese de que o lodo de esgoto, quando aplicado ao solo, com base na norma P 4.230, da CETESB, não causa efeitos tóxicos ao sistema solo-eucalipto. Com o objetivo de testar a hipótese acima, foi proposta a determinação da concentração dos elementos potencialmente tóxicos, a avaliação da toxicidade e genotoxicidade do solo tratado com lodo de esgoto e a verificação da correlação entre essas variáveis. O experimento de campo foi instalado em dezembro de 2004, quando mudas de Eucalyptus grandis foram plantadas e tratadas com lodo de esgoto, nas doses de 0; 7,7; 15,4 e 23,1 tha-1, base seca, em área comercial de cultivo de eucalipto da companhia Suzano Bahia Sul Papel e Celulose S.A., em Itatinga, SP. Amostras de solo foram coletadas aos 18, 21, 24, 27 e 34 meses após a aplicação do lodo. Foram determinadas as concentrações de Cr, Mn, Fe, Ni, Cu, Zn, Cd e Pb no solo, extraídos por DTPA, Mehlich-1 e com HNO3+HCl, e quantificados por ICP-MS. A toxicidade do solo foi avaliada por meio dos testes com Daphnia magna (concentração letal-CL50), com Pseudokcrichirella subcaptata (inibição de crescimento-CI50), com Lactuca sativa (crescimento de raiz) e com Allium cepa (índice mitótico, aberrações cromossômicas e micronúcleos). Os resultados mostraram um aumento nos teores de Cr, Mn, Fe, Ni, Cu, Zn, Cd e Pb no solo de acordo com as doses. Foi observado um aumento da toxicidade para D.magna, P.subcaptata e genotoxicidade e mutagenicidade para A. cepa de acordo com as doses. O lodo de esgoto aplicado ao solo na dose de 15,1 t ha-1, recomendada pela norma da CETESB, não causa efeito tóxico, genotóxico ou mutagênico no sistema solo-planta, de acordo com os testes realizados. Há correlação entre os testes de toxicidade com P. subcaptata, de mutagênicidade com A. cepa (micronúcleos), com os teores dos elementos potencialmente tóxicos no solo. O teste com D. magna constitui uma importante ferramenta na avaliação toxicológica do lodo aplicado ao solo, apesar de não se correlacionar com os teores de elementos potencialmente tóxicos no solo, indicando que a toxicidade do lodo pode estar relacionada também a outros compostos orgânicos tóxicos e/ou agentes patógenos.O teste de toxicidade com L.sativa é inadequado na avaliação toxicológica da aplicação de lodo em relação as doses, por refletir efeitos dos nutrientes e não dos componentes tóxicos do lodo, porém reflete a toxicidade de acordo com o tempo de aplicação do resíduo / The application of sewage sludge in forest systems quests the improvement of the production, favoring the physical, chemistries and biological characteristics of the soil and of the plants. However, the sludge can contain pathogen and, organic and inorganic toxics elements, and the effect of these pollutants in the soil and in the plant is still unknown. It was established the hypothesis that the sewage sludge, when applied to the soil, according to the norm P4.230 of CETESB, doesn\'t cause toxics effects to the soil-eucalyptus system. To test the hypothesis above, it was established as objective, the determination of the concentration of the potentially toxics elements, the evaluation of the toxicity and genotoxicity of the sewage sludge treated soil, and the verification of the correlation among those variables. The field experiment was conducted in December of 2004, when seedlings of Eucalyptus grandis were planted and treated with sewage sludge, in the doses of 0; 7,7; 15,4 and 23,1 tha 1, dry base, in commercial area of eucalyptus cultivation of the Suzano Bahia Sul Papel and Celulose S.A company, in Itatinga, SP. Soil samples were collected to the 18, 21, 24, 27 and 34 months after the application of the sludge. They were established the concentrations of Cr, Mn, Fe, Ni, Cu, Zn, Cd and Pb in the soil, extracted for DTPA, Mehlich-1 and with concentrated HNO3+HCl, and quantified by ICP-MS. The toxicity of the soil was evaluated through the tests with D. magna (lethal concentration -LC50), with Pseudokcrichirella subcaptata (growth inhibition - IC50), with Lactuca sativa (root growth) and with Allium cepa (mitotic index, cromossomic aberration and micronucleus). The results showed an increase in the concentrations of Cr, Mn, Fe, Ni, Cu, Zn, Cd and Pb in the soil in agreement with the doses. An increase of the toxicity was observed for D. magna, P. subcaptata and an increase of the genotoxicity and mutagenicity for A. cepa in agreement with the doses. The applied sewage sludge to the soil in the dose of 15,1t ha-1, recommended by CETESB, doesn\'t cause toxic, genotoxic or mutagenic effect in the system soilplant, in agreement with the accomplished tests. There is correlation among the toxicity tests with P. subcaptata, of mutagenicity with A. cepa (micronucleus) with the concentrations of Cr, Mn, Fe, Ni, Cu, Zn, Cd and Pb in the soil. The test with D. magna is an important tool in the toxicological evaluation of the sludge applied to the soil, however it wasnt correlated with the concentration of potentially toxics elements in the soil, indicating that the toxicity of the sludge can also be related to the other toxic organic compound or pathogen agents. The L.sativa toxicity test is inadequate in the toxicological evaluation of the sludge application, according to the doses, for reflecting effects of the nutrients and it doesnt reflect the toxic components of the sludge, however it reflects the toxicity in agreement with the time of residue application