A flow-through pond at White Sulphur Springs National Fish Hatchery was evaluated as culture environment for juvenile freshwater mussels of Villosa iris and Lampsilis fasciola. Survival did not differ significantly (p = 0.1910) over 93 d for V. iris cultured with silt (mean 49.8% ± SD 14.5) and without (mean 32.9% ± SD 11.7). Survival differed significantly (p <0.0001) between juveniles of V. iris (mean 49.8% ± SD 14.5 at age 93 d) and L. fasciola (mean 6.3% ± SD 4.5 at age 86 d). This may indicate that the pond failed to meet requirements of L. fasciola, or may have resulted from microhabitat variables. Growth did not differ significantly between species (p = 0.1315). Villosa iris reached a mean length of 1.81 mm ± SD 0.67, and L. fasciola 1.78 mm ± SD 0.78. Water quality parameters remained within suitable ranges, and planktonic algal densities were between 2850 - 6892 cells/mL. Survival of V. iris and growth of both species compares favorably to previous culture attempts. Juveniles of V. iris and L. fasciola were exposed to ammonium chloride solutions for 96 h in static renewal conditions at 12°C and 20°C. Calculating LC50 values with the Trimmed Spearman-Karber method, juveniles of L. fasciola (mean 96 h LC50 of 0.26 mg/L NH3-N) were significantly more tolerant of unionized ammonia than juveniles of V. iris (mean 96 h LC50 of 0.11 mg/L NH3-N). The only organisms with reported LC50 values lower than those seen for V. iris juveniles were Ceriodaphnia dubia and Hyella azteca. / Master of Science

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

The effect of 8 tensides on the toxicity of diazinon were investigated by means of topical dose applications to male adult German cockroaches, Blattella germanica (L.). Other diazinon formulations were evaluated for comparison. These were Diazinon 4E, Diazinon 4E plus Igepal CO-630, Oiazinon 4E plus Multi-Film X-77, diazinon in OMSO, diazinon in Stoddard's Solvent, and diazinon in Stoddard's Solvent plus piperonyl butoxide. Five of the tensides formed emulsions that were similar in toxicity to diazinon in Stoddard's Solvent. These were, in order of decreasing L050 's, Bio Film, Tween 80, hexadecyltrimethyl ammonium bromide (HAB), Multi-Film X-77, and Triton X-100. All of the tenside emulsions were more effective than Oiazinon 4E. Emulsions formed with Triton X-100 and Multi-Film X-77 had L050 's significantly lower than the Oiazinon 4E formulation. The two tensides added to Oiazinon 4E seemed to decrease effectiveness. OMSO and piperonyl butoxide were the two most effective additives to diazinon. Both were synergistic with respect to diazinon in Stoddard's Solvent. The results from this investigation indicate that several of the tested formulations may prove effective in cockroach control. Additional studies of these preparations under practical conditions need to be made. / Master of Science

Laboratory bioassays results suggest that early life stages of freshwater mussels are sensitivity to toxicants. However, toxicological databases for unionids are rather limited because standard test methods are yet developed, and no published studies report endpoints for chronic test that are > 9 days. The primary goals of my thesis research were to assess acute and chronic toxicities of chlorine and mercury to early life stages. Inter- and intra-specific species variability in the tolerances of glochidia was observed during acute laboratory bioassays as endpoints were between 8 - 43 ppb for Hg tests, 1.0 - 2.5 ppm for NaCl tests, and 70 - 260 ppb for chlorine (TRC) tests. Glochidia of several species had equal or greater sensitivities to Hg and NaCl than test organisms commonly used to assess environmental risk (i.e.Ceridaphnia dubia, Daphnia magna, Pimephales promelas), whereas they were far more tolerant to TRC than many species. Twenty-one day chronic test endpoints for juveniles were substantially lower than those calculated during acute bioassays with glochidia. Villosa iris 3-mo old juveniles were found to be quite sensitive to Hg as growth was significantly impaired at 8 ppb Hg. Chronic bioassays with TRC revealed a distinct decrease in susceptibility with increased aged for V. iris (relative sensitivities 3-mo > 6-mo > 12-mo), and that 2-mo old Epioblasma capsaeformis were more sensitive than comparable age classes of V. iris. However, both species were tolerant compared to other aquatic organisms, as the lowest endpoint was 20 ppb TRC. / Master of Science

Black Creek is a small watershed located in Wise County, Virginia, west of the town of Norton. At the time of this survey, the watershed encompassed approximately 929 hectares of mine and forest lands with a small recreational area. Black Creek proper is a third-order stream approximately 6.7 km in length from its headwaters to its confluence with the Powell River in Kent Junction. Black Creek and several of the tributaries within the watershed were previously identified as areas impacted by acid mine drainage. The watershed was used in a study to identify sources of acid mine drainage and the best methods for its evaluation. The acid mine drainage sources were first identified using visual inspection and field chemistry. Additional stream segments were then included in the assessment process using metal (aluminum, copper, iron, magnesium, manganese, and zinc) analyses of both overlying water column and sediments. Using an upstream reach of Black Creek as a reference, short-term toxicity testing was employed, as well as a long-term purge study. The pH at sampling locations ranged from 2.75 to 7.87 SU, and conductivity ranged from 196 μmhos/cm to 2040 μmhos/cm. All metals were elevated when compared to the reference. Water column samples collected from locations with low pH were acutely toxic to Daphnia magna and Pimephales promelas. Mortality was high in the elutriant test at locations where pH was low, conductivity was elevated, metals were high, or a combination of these. In the initial sediment tests, all sampling locations were significantly different than the reference for survival of Chironomus tentans and reproduction of D. magna. One location was significantly different than the reference for survival of D. magna. In the sediment tests completed after two months, survival of C. tentans was only different from the control in three locations but was significantly different for growth at all locations. Reproduction by D. magna was again significantly less than the reference at all locations. At eight months, only two locations were significant for survival of C. tentans and after 15 months, no significant differences occurred between any stations. The study indicates that stream segments that are severely impaired by acid mine drainage are easy to identify using visual inspection and field water chemistry. Those that are moderately impaired require more investigation and may not be responsive to short-term toxicity tests. Benthic macroinvertebrates, leaf packs, and periphyton were evaluated in the field. Benthic macroinvertebrate communities and leaf-pack breakdown were evaluated at nine locations, while periphyton was evaluated at the mouth of Black Creek, as well as five sites in the Powell River receiving system. While leaf-pack information and benthic macroinvertebrate samples yielded similar information, benthic sampling was much simpler and less time consuming. Additionally, benthic macroinvertebrate sampling, particularly over several sampling events, was more sensitive at the most severely impacted AMD stations. The stations were broken down into five different categories in order to better determine which evaluation techniques were most sensitive and cost-effective. The five categories were Non-Impaired, Slightly Impaired, Moderately Impaired, Severely Impaired, and Severely pH impaired. Once the locations were categorized, each method used to evaluate toxicity was examined to determine which methods best identified acid mine drainage impairment in the Black Creek watershed. The methods utilized include the following: basic water chemistry; metals analysis of sediments and water column; acute toxicity testing using both D. magna and P. promelas; short-term elutriant and sediment tests; chronic sediment test using C. tentans and D. magna; a purge study; benthic macroinvertebrate sampling; leaf-pack and algal-tile studies. After evaluating these methods, it was determined that using basic water chemistry and benthic macroinvertebrate sampling were the best methods for evaluating acid mine drainage impairment in this watershed. The reference station was identified as Non-Impaired. Two stations located in the lower portions of Black Creek (L11 and L1) were also Non-Impaired or only Slightly Impaired with the benthic macroinvertebrate results indicating little impairment. Stations U2, U6, U7, and BBM were also found to be Slightly Impaired. The station on the margin of the wetland, U5, was Moderately Impaired. Two previously identified areas of impairment, U9 and U10, (Cherry et al. 1995) were identified as Severely pH Impaired and Severely Impaired, respectively. / Master of Science

There is a great deal of concern about the declining freshwater mussel fauna of North America. Although deteriorating water quality and habitat degradation may account for much of the decline, it has been suggested that the exotic Asian clam, Corbicula fluminea, may be having an effect on native unionids. Negative impacts may result directly from competition or indirectly, because of Corbicula population crashes that release ammonia and reduce dissolved oxygen in the sediment. Laboratory tests were conducted to determine the relative sensitivity of native mussel and Asian clam life stages to unionized ammonia, and mussel glochidia were the most sensitive (24-hr LC50 of 0.11 mg/L NH₃-N). Juvenile and adult mussels were similarly sensitivity, with average 96-hr LC50's of 0.49 and 0.52 mg/L NH₃-N, respectively. Adult C. fluminea were the least sensitive, having an average LC50 of 0.80 mg/L NH₃-N. The EPA standard test organism, Ceriodaphnia dubia, had one of the lowest LC50's (0.07 mg/L NH₃-N) of the five species, and the fathead minnow, Pimephales promelas, had the highest (1.18 mg/L). The differing sensitivities of the various life stages are important when trying to determine the impact of an Asian clam dieoff. If a dieoff occurs at a time of year when the more sensitive life stages, such as glochidia are present, then the impact on mussel recruitment may be greater. Two miniature artificial stream tests were used to determine the effect of clam density on dieoff rate, ammonia production and dissolved oxygen levels. Only clams at the highest density of 10,000/m2 experienced 100% mortality. Unionized ammonia levels exceeded 4.0 mg/L, and dissolved oxygen levels dropped below 1.0 mg/L during the dieoff. The amount of unionized ammonia produced was twofold greater than the concentration that produced an LC50 in adult C. fluminea and ~40 times greater than the LC50 for V. iris glochidia. Factors thought to have contributed to the C. fluminea dieoff were flow rate, low dissolved oxygen levels, temperature and perhaps ammonia. A complete dieoff did not occur until flow was stopped and dissolved oxygen concentrations began to drop. One-hundred percent mortality occurred in 38 days for the first test, and 21 days in the second test. Higher water temperatures in the first test (26° C) compared to the second test (average = 21.7°C) are thought to have resulted in the faster dieoff. / Master of Science

Yes / The current paradigm of toxicity testing is set within a framework of Mode-of-Action (MoA)/Adverse Outcome Pathway (AOP) investigations, where novel methodologies alternative to animal testing play a crucial role, and allow to consider causal links between molecular initiating events (MIEs), further key events and an adverse outcome. In silico (computational) models are developed to support toxicity assessment within the MoA/AOP framework. This paper focuses on the evaluation of potential binding to the Liver X Receptor (LXR), as this has been identified among the MIEs leading to liver steatosis within an AOP framework addressing repeated dose and target-organ toxicity. The objective of this study was the development of a priority setting strategy, by means of in silico approaches and chemometric tools, to allow for the screening and ranking of chemicals according to their toxicity potential. As a case study, the present paper outlines the methodologies and procedures that have been developed in the context of the COSMOS/cosmetics safety assessment project [4], which developed computational methods in view of supporting cosmetics safety assessment, to rank chemicals based on their potential binding to LXR. Chemicals are ranked based on molecular and QSAR modelling outcomes. The contribution in this paper is threefold: the QSAR model for LXR dataset, an application of molecular modeling approaches, which have been developed and optimized for drug discovery, in the context of toxicology, and finally ranking chemicals based on diverse modelling outcomes. The novelty in this paper consists of the employment of linear (logistic regression) and non-linear (Random Forest) models in the context of ranking chemicals. The results show that these methods can be successfully applied for prioritization of compounds of major concern for potential liver toxicity, and that they perform better than the ranking methods reported in the literature to date (such as total ordering or data fusion). / European Community’s Seventh Framework Program (FP7/2007-2013) COSMOS Project under grant agreement n° 266835 and from Cosmetics Europe.

Oil spills are well-known adverse anthropogenic events, as they can induce severe impacts on the environment and negative economic consequences. Still, much remains to be learned regarding the effects of crude oil exposure to aquatic organisms. The objectives of this dissertation were to fill some of those knowledge gaps by examining the effects of Deepwater Horizon (DWH) crude oil exposure on teleost kidney development and function. To this end, I analyzed how these effects translate into potential osmoregulatory impairments and investigated the interactive effects of ubiquitous natural factors, such as dissolved organic carbon (DOC) and ultraviolet (UV) light, on acute crude oil toxicity. Results demonstrated that acute early life stage (ELS) crude oil exposure induces developmental defects to the primordial kidney in teleost fish (i.e., the pronephros) as evident by alterations in: (1) transcriptional responses of key genes involved in pronephros development and function and (2) alterations in pronephros morphology. Crude oil-exposed zebrafish (Danio rerio) larvae presented defective pronephric function characterized by reduced renal clearance capacity and altered filtration selectivity, factors that likely contributed to the formation of edema. Latent osmoregulatory implications of crude oil exposure during ELS were observed in red drum (Sciaenops ocellatus) larvae, which manifested reduced survival in hypoosmotic waters, likely due to defective pronephros development and function. Finally, DOC-UV co-exposure slightly reduced acute crude oil photo-enhanced toxicity in red drum larvae. This dissertation provided novel information regarding crude oil toxicity that can be incorporated into environmental risk assessment and management for future oil spills.

Submitted by Cássia Santos (cassia.bcufg@gmail.com) on 2014-08-22T13:26:36Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertacao_Thays_Versao_Final.pdf: 1497222 bytes, checksum: f398ada0d986db4d3fa3c1da26df807a (MD5) / Made available in DSpace on 2014-08-22T13:26:36Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertacao_Thays_Versao_Final.pdf: 1497222 bytes, checksum: f398ada0d986db4d3fa3c1da26df807a (MD5) Previous issue date: 2013-09-03 / In order to define the safety of phytotherapeutic use of plants is important an evaluation of the toxic potential by clinical, laboratory and histopathological studies in animals after exposure to extract of parts of the plant in different intervals of time. Due to bark infusion from species of Aspidosperma is employed without proof of its toxic potential in treatment of the diabetes mellitus, hypercholesterolemia and gastric disorders, this study proposes an experimental test with ethanolic extract of Aspidosperma subincanum to verify if induces acute and subchronic toxicity in heart, liver and kidneys of mices (Mus musculus). The animals (male and female) received orally a 75 mg/kg, 150 mg/kg and 300 mg/kg of the extract for subchronic intoxication evaluation by daily exposure along of 28 days. In the acute toxicity evaluation were used female mices that received an only dose of 300mg/kg and 2000 mg/kg of the extract and observed during to 14 days. Pharmacological tests were conducted to check the possible action of the extract in central nervous system in male mices submitted to 200 mg/kg, 400 mg/kg and 750 mg/kg by oral, subcutaneous and intraperitoneal ways. The animals showed some signs of neurotoxicity whose intensity was proportional to extract concentration and died with oral dose of 2000 mg/kg. Hematological parameters did not showed any significant abnormalities. Biochemical tests did not presented any changes, except ALT and AST measures which presented significant increases in exposed groups in relation to control group. Concerning histopathological exam it was possible to detect lesions that suggest the existence of injuries in liver (microvacuolization and hyperemia) and kidney (hyperemia and hemorrhage). Thus, it can be concluded that ethanolic extract of Aspidosperma subincanum is toxic orally, both acute and subcronically, in mices and the estimated median lethal dosis (LD50) was below 2000 mg/kg. / Para se determinar a segurança do consumo de fitoterápicos é imperativo uma avaliação do pontecial tóxico por meio de exames clínicos, laboratoriais e histopatológicos de animais após exposição ao extrato de partes da planta em diferentes intervalos de tempo. Pelo fato de infusos da casca de espécies do gênero Aspidosperma serem empregados, sem comprovação de seu pontencial tóxico, no tratamento do diabetes mellitus, da hipercolesterolemia e de distúrbios gástricos, propõe-se um ensaio experimental com o objetivo de avaliar se o extrato etanólico de Aspidosperma subincanum (EEAs) induz toxicidade aguda e subcrônica no coração, fígado e rins de camundongos (Mus musculus). Os animais (machos e fêmeas) receberam por via oral a dose de 75, 150 e 300 mg/kg do extrato para a avaliação de intoxicação subcrônica por 28 dias de exposição diária ao extrato. Na avaliação da toxicidade aguda foram utilizados camundongos fêmeas que receberam a dose única de 300 e 2000 mg/kg do extrato e observados por 14 dias. Testes farmacológicos foram conduzidos para verificar a possível ação desse extrato no sistema nervoso central, sendo utilizados camundongos machos e as doses de 200, 400 e 750mg/kg por via oral, subcutânea e intraperitoneal. Os animais apresentaram alguns sinais de neurotoxicidade e os sinais tiveram intensidade proporcional à concentração do extrato, sendo letais na dose de 2000 mg/kg via oral. Dentre os exames laboratoriais realizados, o eritrograma, plaquetograma e leucograma, não apresentaram nenhuma alteração significativa. Nas provas bioquímicas não foram observadas alterações dignas de nota, à exceção de ALT e AST que apresentaram elevação significativa nos grupos expostos em relação ao grupo controle. Em relação ao exame histopatológico, observaram-se alterações compatíveis com injúrias estruturais hepáticas (microvacuolização e hiperemia) e renais (hiperemia e hemorragia). Conclui-se que o EEAs pode ser considerado tóxico quando administrado por via oral, tanto agudo como subcronicamente, em camundongos e a dose letal mediana (DL50) estimada encontra-se abaixo de 2000 mg/kg.

<p>Pesticides are designed to control or eliminate pests such as insects, rodents, weeds,<br /> bacteria, and fungi. They are used at a global scale for agricultural produce. Although<br /> pesticides play a significant role in increasing food production and eliminating diseases,<br /> exposure to pesticides may be harmful to non-target organisms. As a result concern over<br /> safety and resistance to pesticides has increased and there is pressure to reduce use and<br /> search for more environmentally and toxicologically safe and efficacious pesticides. Most<br /> pesticides currently in use are synthetic / therefore an alternative to synthetic pesticides is<br /> the use of naturally occurring products/ botanicals with pesticidal properties.</p> <p>Two plants indigenous to South African with pesticidal properties were chosen for this<br /> study. Dicerothamnus rhinocerotis (D. rhinocerotis) and Galenia africana (G. africana)<br /> have potential antifungal properties thus, may have potential use on agricultural produce<br /> as fungicides. Galenia africana and D. rhinocerotis extracts inhibit growth of B. cinerea<br /> (a fungal pathogen) at concentrations greater than 31.25 mg/ml and 125mg/ml<br /> respectively. A major consideration in approving pesticides for use is whether they pose<br /> an unreasonable risk to humans and to the environment. Toxicity studies are required to<br /> determine the safety of the plant extracts.</p> <p>The purpose of this study was to evaluate potential toxicity of ethanol extracts of D.<br /> rhinocerotis and G. africana, which is important when designing practices to reduce or<br /> eliminate excess exposure to them. Natural plant products with pesticidal properties could<br /> provide an alternative to synthetic pesticides and may thus effectively reduce resistance<br /> levels.<br /> <br /> <br /> &nbsp / </p>