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The larval and pupal stages of Chironomus riparius are benthic dwellers which ingest sediment, and are commonly prey. In an environment with elevated selenium concentrations, they can accumulate it and transfer it to higher trophic level organisms upon being ingested. This study was conducted to: 1. Develop a method for performing acute toxicity tests using Chironomus riparius. 2. Establish relationships between dry mass and selenium content, and between dry mass and selenium body burden. 3. Determine whether bioaccumulation or bioconcentration contributed more to the selenium content and body burden of individual larvae. 4. Determine selenium concentrations which were acutely and chronically toxic to C. riparius, and whether previous exposure changed the acutely toxic concentration. 5. Evaluate adequacy of national surface water selenium criterion with respect to these data. In acute toxicity tests, 1 larva per 4 ml test solution was an acceptable organism density, and test solutions were successfully renewed by siphoning and refilling the test chamber. Regression showed that larval selenium content was linearly dependent on dry mass within instar, and body burden was negatively exponentially dependent on dry mass. Predicted body burdens were linearly dependent on dissolved selenium concentration. This indicated that bioconcentration was more important than bioaccumulation in determining body burdens. C. riparius readily acclimated after prolonged exposure to dissolved selenium, but became slightly more sensitive to selenium after prolonged exposure to substrate-adsorbed selenium. The national water quality selenium criteria may not protect against biomagnification in all ecosystems, and should be based on some environmental chemical factors. / Master of Science

To protect the environment from contaminants, environmental risk assessment (ERA) evaluates the risk of adverse effects to populations, communities and ecosystems. Environmental management decisions rely on ERAs, which commonly are based on a few endpoints at the individual organism level. To bridge the gap between what is measured and what is intended for protection, individual-level effects can be integrated in population models, and translated to the population level. The general aim of this doctoral thesis was to extrapolate individual-level effects of harpacticoid copepods to the population level by developing and using population models. Matrix models and individual based models were developed and applied to life-history data of Nitocra spinipes and Amphiascus tenuiremis, and demographic equations were used to calculate population-level effects in low- and high-density populations. As a basis for the population models, individual-level processes were studied. Development was found to be more sensitive compared to reproduction in standard ecotoxicity tests measuring life-history data. Additional experimental animals would improve statistical power for reproductive endpoints, but at high labor and cost. Therefore, a new test-design was developed in this thesis. Exposing animals in groups included a higher number of animals without increased workload. The number of reproducing females was increased, and the statistical power of reproduction was improved. Individual-level effects were more or equally sensitive compared to population-level effects, and individual-level effects were translated to the population level to various degrees by population models of different complexities. More complex models showed stronger effects at the population level compared to the simpler models. Density dependence affected N. spinipes populations negatively so that toxicant effects were stronger at higher population densities. The tools presented here can be used to assess the toxicity of environmental contaminants at the individual and population level, improve ERA, and thereby the basis for environmental management. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Submitted. Paper 4: Manuscript.</p>

Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 4 uppsatser.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / O esqueleto quinona foi identificado como um importante grupo farmacofÃrico para atividade citotÃxica de vÃrios compostos utilizados na clÃnica, constituindo ainda uma das maiores classes de agentes anticÃncer. A &#946;-lapachona à uma das quinonas mais estudadas nos Ãltimos anos. Suas aplicaÃÃes mais importantes estÃo relacionadas Ãs aÃÃes contra vÃrias cÃlulas tumorais. Seu derivado, nor-&#946;-lapachona (composto 1), tem atividade anticÃncer similar. Assim, o objetivo desse trabalho foi avaliar o mecanismo de aÃÃo envolvido na citotoxicidade do composto 1 e de seu derivado nitrofenilamino (composto 2) em cÃlulas leucÃmicas HL-60. Inicialmente foi investigado o efeito desses compostos na viabilidade de cÃlulas HL-60 apÃs 24 horas de incubaÃÃo, mostrando CI50 de 2,92 e 0,48 &#956;M para os compostos 1 e 2, respectivamente. Acerca da seletividade celular, o composto 1 mostrou forte seletividade para cÃlulas tumorais, enquanto que o seu derivado foi apenas parcialmente seletivo. Estudos feitos em cÃlulas HL-60 indicaram que o composto 2 induz morte celular por apoptose como mostrado pelas mudanÃas morfolÃgicas, fragmentaÃÃo do DNA, despolarizaÃÃo da membrana mitocondrial e externalizaÃÃo da fosfatidilserina. Ambos compostos aumentaram a geraÃÃo de espÃcies reativas de oxigÃnio (EROs). Nossos resultados sugerem que a introduÃÃo do radical nitrofenilamino na posiÃÃo 3 do anel furano aumenta a citotoxicidade da nor-&#61538;-lapachona em cÃlulas HL-60. Esses achados apontam para o potencial dessas quinonas sintÃticas como modelo para a produÃÃo de novos compostos com propriedades anticÃncer. / The quinone moiety has been identified as an important pharmacophoric group for cytotoxic activity of several compounds clinically used, constituting just one of the major classes of anticancer agents. &#946;-lapachone is one of the most studied quinones in the last years. Its most important applications are related to its action against several cancer cells. Its derivative, nor-&#946;-lapachone (compound 1), has similar anticancer activity. Thus, the aim of this work was to evaluate the mechanism of action involved in nor-&#61538;-lapachone and its nitrophenylamino derivative (compound 2) cytotoxicity in a leukemia cells model of HL-60 cell line. Initially it was investigated the effect of both the compounds on HL-60 cells viability after 24 hours of incubation, showing IC50 values of 2.92 and 0.48 &#956;M to compounds 1 and 2, respectively. Considering the selectivity, compound 1 showed strong selectivity to cancer cells, while its derivative was only partially selective. Studies performed in HL-60 cells, after 24 hours, indicated that compound 2 induces cell death by apoptosis as showed by morphological changes, DNA fragmentation, mitochondrial membrane depolarization and phosphatidylserine externalization. Both tested compounds increased generation of reactive oxygen species (ROS). Our results suggest that a nitrophenylamino radical introduction at position 3 of the furane ring enhances the cytotoxicity of nor-&#61538;-lapachone in HL-60 cell line. These findings highlight the potential of these synthetic quinones as prototypes molecules to produce new compounds with anticancer properties.

This research was divided into four objectives for assessing the impacts of coal mining on ecosystem health. The first objective was to provide an ecotoxicological assessment in the upper Clinch River using standard bioassessment techniques. Analysis of sediments and interstitial water (porewater) indicate higher concentrations of trace metals in samples from sites located above both a power plant (CRP) and Dumps Creek mining influences. The furthest sampling site located near Pounding Mill, Virginia (CR-PM) had higher concentrations of aluminum (2,250.9 mg/kg), copper (5.9 mg/kg) and iron (12,322.6 mg/kg) compared to samples collected directly below the Dumps Creek confluence (site CR-2). Similar results were obtained from bioaccumulation in-situ tests with the Asian clam (Corbicula fluminea) in 2009. Aluminum (7.81 mg/kg), Fe (48.25 mg/kg) and Zn (7.69 mg/kg) were accumulated in higher concentrations at CR-PM site than CR-2. However, the site located below the CRP effluent discharges (CR-3L) on the left bank had substantially higher concentrations of Al (14.19 mg/kg), Cu (6.78 mg/kg), Fe (88.78 mg/kg) and Zn (7.75 mg/kg) than both CR-PM and samples collected directly opposite of this site at CR-3R. To further understand the potential impact active mining on the Clinch River, a more comprehensive ecotoxicological evaluation was conducting in the Dumps Creek subwatershed. Field bioassessments determined that biological impairment occurred directly below a deep mine discharge (CBP 001), which was characterized by a distinct hydrogen sulfide odor. Total abundance and richness of benthic macroinvertebrates decreased to 3.5-20 and 1.25-2.3, respectively at DC-1 Dn. The discharge also caused the proliferation of a sulfur-oxidizing bacterium, Thiothrix nivea. During continuous discharge of the effluent, the bacteria was observed coating all surfaces at DC-1 Dn and may also contribute to an Fe-encrusted biofilm observed on in-situ clams at downstream site, DC-2 Dn. Toxicity tests with mining effluents indicate some potential toxicity of the 001 discharge, but this was variable between test organisms. Selecting the most appropriate test species for sediment and water column assays has been a primary goal for ecotoxicologists. Standard test organisms and established test guidelines exist, but US EPA recommended species may not be the most sensitive organisms to anthropogenic inputs. Therefore, Chapter Three and Four addressed the use of mayflies in routine laboratory testing. Preliminary results of toxicity tests with the mayfly, Isonychia sp. (Ephemeroptera) suggested that Isonychia were moderately sensitive to NaCl after 96-hr with an average LC50 value of 3.10 g NaCl/L. When exposed to a coal-mine processed effluent, Isonychia generated LC50 values that ranged from 13 to 39% effluent and were more sensitive to the effluent than Ceriodaphnia dubia. Based on results of the feasibility study in presented in Chapter Four, field collected organisms appear to be too unpredictable in test responses and therefore, such tests would be unreliable as stand-alone indicators of effluent toxicity. / Ph. D.

Análises ecotoxicológicas vêm sendo amplamente empregadas no monitoramento de amostras ambientais, efluentes industriais e substâncias complexas. Com o objetivo de avaliar a toxicidade de fluidos de usinagem usados na indústria de peças metálicas, foram feitos ensaios de toxicidade aguda com espécies de três diferentes níveis tróficos: Vibrio fischeri, Daphnia similis, Daphnia laevis e Danio rerio. As amostras dos fluidos foram também analisadas quanto aos valores de DQO, fenol, pH, cor, densidade e surfactantes. Os parâmetros físicos e químicos encontram-se dentro dos limites da legislação CONAMA 357 (D.O.U., 2005). Os resultados dos bioensaios revelaram que os fluidos de usinagem apresentaram toxicidade aos organismos empregados neste estudo, e que o tratamento das amostras com radiação gama não foi eficiente na diminuição da toxicidade dessas matrizes. Foi observado que a radiação gama potencializou o efeito tóxico dos fluidos estudados. A biodegradação em solo demonstrou ser efetiva para os fluidos de usinagem e bactérias endêmicas foram identificadas e isoladas para possível utilização no tratamento de áreas contaminadas com fluidos de usinagem. O monitoramento e gestão dos resíduos de fluido de usinagem são necessários para a preservação dos organismos aquáticos devido a sua toxicidade elevada. / Ecotoxicological analyses have being used to monitor environmental samples, industrial effluents and complex substances. With the objective to analyze the toxicity of cutting fluids used in the machinery industry, acute toxicity test with species of three different throphic levels: Vibrio fischeri, Daphnia similis, Daphnia laevis e Danio rerio, were performing. The samples of fluids were analyzed by COD, phenol, pH, color, density and surfactants. The physical and chemical parameters are the according with the brazilian law, CONAMA 357 (D.O.U. 2005}. The results of the toxicity tests showed that the cutting fluids have high toxicity to the organisms used in this study and the gamma radiation treatment was not efficient to decrease the matrix. The biodegradation in soil demonstrated be effective to the cutting fluids and the indigenous bacteria were identified and isolated to possible treatment of soils contaminated with these kinds of substances. The monitoring and management of residues of cutting fluids are necessary to preservation of aquatic live, in consequence of their high toxicity.

O presente trabalho teve como objetivo analisar a qualidade da água das represas de captação do Ribeirão das Anhumas e do Ribeirão das Cruzes, bem como da água tratada da estação de tratamento Fonte Luminosa, no município de Araraquara (SP). Para tanto, foram realizadas análises das características físicas, químicas e biológicas da água, estudo de comunidade fitoplanctônica, e testes de toxidade aguda e crônica com o microcrustáceo Ceriodaphnia silvestrii (Cladocera, Crustacea). O período de estudo foi de dezembro de 2000 a novembro de 2001. Na água da represa da Ribeirão das Anhumas, a concentração de oxigênio dissolvido foi, em geral, inferior ao limite estabelecido pela legislação para águas naturais. Tanto na água da represa do Ribeirão das Cruzes como em Anhumas, alguns metais apresentaram concentrações superiores ao limite estabelecido pela legislação para águas naturais. Na água tratada, alguns metais também apresentaram concentrações superiores ao limite estabelecido pela legislação para água potável. As águas das represas de captação não causaram toxicidade aguda nem crônica ao organismo-teste. A água da entrada (após aplicação de cal) da estação de tratamento causou efeitos crônicos principalmente sobre a fecundidade do organismo-teste. A água tratada causou toxicidade aguda e crônica ao organismo-teste. As diatomáceas (Bacillariophyceae) foram dominantes na represa do Ribeirão das Cruzes e, principalmente, em Anhumas. As algas Chlorophyceae foram as mais abundantes na água tratada em ambos os períodos estudados. / The present work analysed the water quality of the reservoirs Ribeirão das Cruzes and Ribeirão das Anhumas, used to store and supply water for the Fonte Luminosa water treatment plant, in Araraquara, SP. For that, physical, chemical and biological analyses of water were performed, as well as a study of phytoplankton community. The work also included acute and chronic toxicity testing of the water before and after treatment with the microcrustacean Ceriodaphnia silvestrii (Cladocera, Crustacea) as a test organism. The period of study was between December/2000 to November/2001. Dissolved oxygen was below the established limit by legislation for natural waters at the Ribeirão das Anhumas reservoir. Some metals in the Ribeirão das Anhumas and Ribeirão das Cruzes reservoirs were over the established limit by legislation for natural waters. Some metaIs in treated water were also over legislation for potable water. Reservoir waters did not cause neither acute nor chronic toxicity on test organism. Water with lime, from water treatment plant, caused chronic effects on the reproduction of the test organism. Treated water cause acute and chronic toxicity on test organism, with harmful effects on survival and reproduction. Diatoms (Bacillariophyceae) dominated in the phytoplankton of Ribeirão das Cruzes and Ribeirão das Anhumas reservoirs. Chlorophyceae were the most abundant algae in treated water.

Lodos de duas Estações de Tratamento de Água (ETA) que utilizam cloreto férrico (ETA-Paiol-ETA-1) e sulfato de alumínio (ETA-SAAE-ETA-2) como coagulantes, foram caracterizados físico-quimicamente em duas estações do ano (chuvosa e seca) e submetidos a testes de toxicidade aguda com microcrustáceos (Daphnia similis), quironomídeos (Chironomus xanthus) e peixes (Hyphessobrycon eques) e de toxicidade crônica com microcrustáceos (D. similis). Observou-se ainda os efeitos destes lodos na comunidade bentônica dos corpos d\'água que recebem os lançamentos das ETAs. Os efeitos dos lodos nos testes de toxicidade aguda foram observados em relação a mortalidade, e, quanto aos testes de toxicidade crônica, observou-se os efeitos na reprodução (número de neonatas) e na mortalidade. Em geral, os lodos das duas ETAs não causaram toxicidade aguda aos organismos-teste, ocorrendo apenas indícios de toxicidade. O lodo da ETA que utilizava cloreto férrico causou toxicidade crônica, que foi observada na reprodução (baixo número de neonatas) e na alta taxa de mortalidade, enquanto que o lodo da ETA que utilizava sulfato de alumínio causou toxicidade crônica evidenciada apenas em relação a reprodução. Os lodos causaram efeitos adversos à fauna bentônica, evidenciados pela predominância de Diptera nos pontos de lançamento das ETAs nos corpos receptores. Constatou-se ainda a variação temporal na caracterização dos lodos em relação aos parâmetros: pH, turbidez, série de sólidos, nutrientes (N e P) e metais (AI, Mn e Fe), sendo que estes, juntamente com a DQO, foram identificados como os principais parâmetros que aumentam a degradação dos corpos receptores que recebem os lançamentos dos efluentes das ETAs. Portanto, a disposição \"in natura\" dos efluentes das ETAs prejudica à biota aquática e compromete a qualidade da água e do sedimento dos corpos receptores. / Sludges from two water treatment plants, which use ferric chloride (ETA-Paiol-ETA-1) and alum (ETA-SAAE-ETA-2) as coagulants were characterized physicall y and chemically at two seasons (wet and dry). The sludge was subjected to acute toxicity tests to cladoceran (Daphnis similis), midges (Chironomus xanthus) and fishes (Hyphessobrycon eques) and chronic toxicity tests using clacloceran (D. similis). It also was observed the impact of discharged sludge on benthic communities in surface waters at two water treatment plants. Acute toxicity tests evaluated sludge effects on mortality, while chronic toxicity tests assessed effects on reproduction and mortality. In general, sludges from two water treatment plants did not show acute toxicity on organisms-test, only toxicity traces. Ferric chloride sludge showed chronic toxicity on lower brood production and high mortality rate. Alum sludge showed chronic toxicity only on brood production. Sludges from water treatment plants caused detrimental effects to benthic macroinvertebrate communities. This effect was determined by Diptera predominance at bodies receiving discharge from water treatment plants. The turbidity, solids series, nutrients (N and P) and metals (Al, Mn and Fe) in the sludge vary when experiments are carried out in the dry and wet season. Together with COD, there were the main parameters that cause the increase in degradation of bodies receiving discharge from water treatment plants. Thus the disposal of \"in natura\" effluents from water treatment plants damages aquatic biota and affects receiving bodies water and sediment quality.