Spelling suggestions: "subject:"aquatic toxicity"" "subject:"quatic toxicity""
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Environmental fate prediction using molecular modelling techniquesLeeke, Caleb January 1999 (has links)
No description available.
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The Interactive Effects of Chemical and Natural Stressors on an Aquatic Community and its Predator-Prey DynamicsHaiden McCurry (19200004) 24 July 2024 (has links)
<p dir="ltr">Aquatic ecosystems and their inhabitants are no strangers to stressors. Natural stressors like disease, competition, and predation have a near constant presence in these environments and are often accompanied by human-induced stressors like climate change and chemical contaminants. Chemical contaminants like pesticides are often found in aquatic systems located near agriculture and can have detrimental effects on wildlife. Although natural stressors and pesticides often occur at the same time, their combined interactions still require further investigation to understand, as some pesticides, like fungicides, are frequently under researched. Additionally, fungicides also are lacking in research pertaining to combined chemical stressors. Studying the interactive effects of combined stressors, whether natural or human-induced, is crucial for applying laboratory findings to natural environments.</p><p dir="ltr">Here, I conducted an outdoor mesocosm experiment and multiple laboratory experiments to broadly assess the interactive effects of the fungicide chlorothalonil. More specifically, I explored 1) the interactive effects of the herbicide atrazine and chlorothalonil on an aquatic community, 2) the interaction between chlorothalonil and predator-induced stress of three tadpole species, and 3) the impacts of chlorothalonil on amphibian predator-prey dynamics using tadpoles and larval salamanders. First, to test my hypothesis that atrazine and chlorothalonil will have combined interactions that negatively impact an aquatic community, I conducted a mesocosm experiment where I exposed an aquatic community to atrazine, chlorothalonil, and the combination of the two pesticides. I found that the two pesticides do hold the potential to interact in certain cases, but their main effects alone are often just as damaging, especially for chlorothalonil where an environmentally relevant concentration caused near total morality for bullfrog tadpoles.</p><p dir="ltr">Next, I conducted a laboratory experiment with tadpoles and caged predators exposed to a sublethal concentration of chlorothalonil to test my hypothesis that the combination of predator-induced stress and chlorothalonil will decrease tadpole survival and alter tadpole behavior. I found that chlorothalonil alters tadpole behavior by significantly reducing activity levels in all three study species. However, no evidence was found for the interaction of the two stressors decreasing survival.</p><p dir="ltr">Lastly, to test my hypothesis that the toxicity of chlorothalonil will reduce tadpole behavioral responses and thereby increase their predation risk, I conducted a laboratory experiment with free-swimming tadpoles as prey and larval tiger salamanders as predators, exposed to different combinations of chlorothalonil exposure for the prey or predator. I found no meaningful differences in survival curves for the different combinations of prey and predator, but leopard frog tadpole final survival was lower in the higher chlorothalonil dose treatment due to predation.</p><p dir="ltr">Overall, these studies have assisted in filling research gaps on fungicides and their impact on predator-prey dynamics and aquatic communities. This work provided insights into the direct impacts of the herbicide atrazine and the fungicide chlorothalonil on aquatic species, and their potential to interact with natural stressors, emphasizing the need to protect natural ecosystems from chemical stressors.</p>
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Avaliação da toxicidade e remoção da cor de um efluente têxtil submetido ao tratamento com feixe de elétrons / Evaluation of toxicity and removal of color in textile effluent submitted to the treatment of electron beamMorais, Aline Viana de 22 April 2015 (has links)
A indústria têxtil está entre uma das principais atividades do Brasil, sendo relevante em número de empregos, quantidade e diversidade de produtos e principalmente pelo volume de água utilizado nos processos industriais e na geração de efluentes. Esses efluentes são misturas complexas que se caracterizam pela presença de corantes, surfactantes, metais, sequestrantes, sais entre outras substâncias químicas com potencial tóxico a biota aquática. Considerando a escassez de tratamentos adequados a esses efluentes, novas tecnologias são essenciais em que se destacam os processos de oxidação avançada como a radiação ionizante por feixe de elétrons. Esse estudo contempla o preparo de um efluente têxtil padrão em laboratório de química têxtil e seu tratamento por feixe de elétrons proveniente de acelerador de elétrons a fim de diminuir a toxicidade e coloração intensa decorrente do corante C.I. Blue 222. O tratamento promoveu diminuição de toxicidade aguda aos organismos expostos, com eficiência de 34,55% para o micro-crustáceo Daphnia similis e de 47,83% para o rotífero Brachionus plicatilis na dose de 2,5 kGy. No ensaio com a bactéria Vibrio fischeri foi obtido o melhor resultado após o tratamento com dose de 5 kGy e eficiência de 57,29%. A redução da cor foi superior a 90% a partir da dose de 2,5 kGy. Neste trabalho também foram realizados ensaios preliminares de toxicidade aguda quanto à sensibilidade dos organismos D. similis e V. fischeri à exposição de alguns dos produtos utilizados no processo de alvejamento e tingimento, além de duas simulações de reuso de água em novos processos têxteis a partir do efluente tratado com feixe de elétrons. / The textile industry is among the main activities Brazil, being relevant in number of jobs, quantity and diversity of products and mainly by the volume of water used in industrial processes and effluent generation. These effluents are complex mixtures which are characterized by the presence of dyes, surfactants, metal sequestering agents, salts and other potentially toxic chemicals for the aquatic biota. Considering the lack of adequate waste management to these treatments, new technologies are essential in highlighting the advanced oxidation processes such as ionizing radiation electron beam. This study includes the preparation of a standard textile effluent chemical laboratory and its treatment by electron beam from electron accelerator in order to reduce the toxicity and intense staining resulting from CI. Blue 222 dye. The treatment caused a reduction in toxicity to exposed organisms with 34.55% efficiency for the Daphnia similis micro-crustacean and 47.83% for Brachionus plicatilis rotifer at a dose of 2.5 kGy. The Vibrio fischeri bacteria obtained better results after treatment with a dose of 5 kGy showing 57.29% efficiency. Color reduction was greater than 90% at a dose of 2.5 kGy. This experiment has also carried out some preliminary tests on the sensitivity of the D. similis and V. fischeri organisms to exposure of some of the products used in this bleaching and dyeing and two water reuse simulations in new textile processing after the treating the effluent with electron beam.
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Avaliação da toxicidade e remoção da cor de um efluente têxtil submetido ao tratamento com feixe de elétrons / Evaluation of toxicity and removal of color in textile effluent submitted to the treatment of electron beamAline Viana de Morais 22 April 2015 (has links)
A indústria têxtil está entre uma das principais atividades do Brasil, sendo relevante em número de empregos, quantidade e diversidade de produtos e principalmente pelo volume de água utilizado nos processos industriais e na geração de efluentes. Esses efluentes são misturas complexas que se caracterizam pela presença de corantes, surfactantes, metais, sequestrantes, sais entre outras substâncias químicas com potencial tóxico a biota aquática. Considerando a escassez de tratamentos adequados a esses efluentes, novas tecnologias são essenciais em que se destacam os processos de oxidação avançada como a radiação ionizante por feixe de elétrons. Esse estudo contempla o preparo de um efluente têxtil padrão em laboratório de química têxtil e seu tratamento por feixe de elétrons proveniente de acelerador de elétrons a fim de diminuir a toxicidade e coloração intensa decorrente do corante C.I. Blue 222. O tratamento promoveu diminuição de toxicidade aguda aos organismos expostos, com eficiência de 34,55% para o micro-crustáceo Daphnia similis e de 47,83% para o rotífero Brachionus plicatilis na dose de 2,5 kGy. No ensaio com a bactéria Vibrio fischeri foi obtido o melhor resultado após o tratamento com dose de 5 kGy e eficiência de 57,29%. A redução da cor foi superior a 90% a partir da dose de 2,5 kGy. Neste trabalho também foram realizados ensaios preliminares de toxicidade aguda quanto à sensibilidade dos organismos D. similis e V. fischeri à exposição de alguns dos produtos utilizados no processo de alvejamento e tingimento, além de duas simulações de reuso de água em novos processos têxteis a partir do efluente tratado com feixe de elétrons. / The textile industry is among the main activities Brazil, being relevant in number of jobs, quantity and diversity of products and mainly by the volume of water used in industrial processes and effluent generation. These effluents are complex mixtures which are characterized by the presence of dyes, surfactants, metal sequestering agents, salts and other potentially toxic chemicals for the aquatic biota. Considering the lack of adequate waste management to these treatments, new technologies are essential in highlighting the advanced oxidation processes such as ionizing radiation electron beam. This study includes the preparation of a standard textile effluent chemical laboratory and its treatment by electron beam from electron accelerator in order to reduce the toxicity and intense staining resulting from CI. Blue 222 dye. The treatment caused a reduction in toxicity to exposed organisms with 34.55% efficiency for the Daphnia similis micro-crustacean and 47.83% for Brachionus plicatilis rotifer at a dose of 2.5 kGy. The Vibrio fischeri bacteria obtained better results after treatment with a dose of 5 kGy showing 57.29% efficiency. Color reduction was greater than 90% at a dose of 2.5 kGy. This experiment has also carried out some preliminary tests on the sensitivity of the D. similis and V. fischeri organisms to exposure of some of the products used in this bleaching and dyeing and two water reuse simulations in new textile processing after the treating the effluent with electron beam.
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Distribution of Trace Elements in Cumberland River Basin Reservoir SedimentsBenneyworth, Laura Mahoney 01 December 2011 (has links)
The U.S. Army Corps of Engineers, Nashville District, maintains ten reservoirs in the Cumberland River Basin in Kentucky and Tennessee, and has been monitoring sediment chemistry in the reservoirs since 1994. The purpose of this study is to evaluate the sediment data collected from the reservoirs from 1994 to 2010 to determine if there are any spatial patterns of the trace elements: arsenic, beryllium, cadmium, chromium, copper, lead, mercury, nickel, and zinc. The results indicated that trace element levels were consistent with national baseline concentrations measured by the U.S. Geological Survey. Center Hill reservoir had the greatest number of trace element concentrations (all except cadmium) that were significantly higher when compared to all other reservoirs. The degree of urbanization in the reservoir basins was based on population density from the 2000 Census and the percentage of developed land using the 2006 national land cover dataset. Aquatic toxicity values were used as a measure of sediment quality. The reservoirs with the worst aquatic toxicity rankings were not the most urban, instead they were the reservoirs with the longest retention times. Therefore, it may be concluded that retention time has a larger effect on Cumberland River Basin sediment concentrations than the type of land use or the degree of urbanization. The results also indicate that it may be prudent to include an evaluation of quality based on aquatic toxicity when monitoring sediment quality, and that when reservoirs are the subject of sediment quality assessments, the consideration of the physical properties of the reservoir, especially the retention time, is essential for a comprehensive evaluation. This may also imply that sediment quality in reservoirs may effectively be regulated by water resource management techniques at the reservoirs that affect retention time.
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Avaliação da exposição aguda e sub-letal ao glifosato (N-fosfometil-glicina) e ao AMPA (ácido amino-metil-fosfônico) em brânquias e fígado de Poecilia reticulata com o emprego de biomarcadores moleculares e morfológicos / Evaluation of acute and sub-lethal exposure to glyphosate (N-phosphomethyl-glycine) and to AMPA (amino-methyl-phosphonic acid) in gills and liver of Poecilia reticulata using molecular and morphological biomarkersAntunes, Adriana Maria 15 February 2013 (has links)
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Previous issue date: 2013-02-15 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The present research aimed to investigate the acute toxicity of glyphosate (Nphosphomethyl-glycine),
the active ingredient of Roundup®, as well as of
aminomethylphosphonic acid (AMPA), its main degradation product, in the teleost fish
Poecilia reticulata, commonly known as guppies. Thus, were performed tests Lethal
Concentration mean (LC50) and behavioral, histopathology and proteomics analysis. Male
and female P. reticulata presented median lethal concentration (LC50) at 96h the values of
68.78 and 70.87 mg/L for glyphosate and 180.00 and 164.32 mg/L for AMPA,
respectively, characterizing them as practically non toxic compounds to guppies. However,
the results of behavioral analyses showed that both products generate stressing situations to
the fish, causing behavioral changes such shock against the tank walls, hypoactivity,
irregular swimming, swimming on the surface of water, darkening of the body,
aggressiveness, and lethargy. Histopathological and morphometric analyses of liver and
gill of guppies exposed to sublethal concentrations of glyphosate (35mg/L) and AMPA
(82 mg/L) indicated that both organs were affected . The gills of fish exposed to the
tested products presented higher reaction rates to progressive changes, such as proliferation
of the interlamellar epithelium and partial and total fusion of secondary lamellae. Liver
presented higher reaction rates to regressive changes, such as steatosis, pyknotic nuclei,
and necrosis. The proteomic analysis showed that Glyphosate induces differential liver
proteins in P. reticulata. The image analysis allowed measuring 225 spots in the control
group and 180 spots in the group exposed to Glyphosate. Of this total, 88 spots were
exclusive to the control group and 43 spots were exclusive of the treated group. Of the 137
spots matched between control and treated groups 13 were down regulated and 8 were up
regulated due to sublethal exposure to Glyphosate. The behavioral, histopathological and
proteomic changes observed indicated that, although considered to have low toxicity to
animals in the guides that evaluate toxicity of chemicals, both glyphosate and AMPA
promote that are deleterious to animal health, indicating the need to establish new
parameters or modify concepts indicating the need to use several biomarkers, beyond
assessing the mortality rate, to establish a more reliable criteria for toxicity parameters. / A presente pesquisa teve como objetivo investigar a toxicidade aguda do Glifosato (Nfosfometil-glicina),
princípio ativo dos herbicidas Roundup, e do AMPA (ácido aminometil-fosfônico),
seu principal produto de degradação. O sistema-modelo eleito para a
investigação foi o teleósteo Poecilia reticulata. Realizaram-se testes de Concentração Letal
média (CL50), análises comportamentais, histopatológicas e proteômicas. Os dados de
mortalidade coletados durante o teste de Concentração Letal média (CL50) permitiram
determinar os valores de 68,78 e 70,87 mg/L como CL50 do Glifosato e os valores de 180 e
164,32 mg/L como a CL50 do AMPA para machos e fêmeas de P. reticulata
respectivamente. Tais valores caracterizam o Glifosato e o AMPA como praticamente não
tóxico aos guarus em testes de toxicidade aguda. No entanto, os resultados das análises
comportamentais também realizadas durante a CL50 mostraram que ambos os produtos
testes são capazes de gerar situações de estresse aos peixes, causando alterações de
comportamento como choques contra as paredes do aquário, hipoatividade, natação
irregular, nado na superfície da água, escurecimento corporal, agressividade e letargia. As
análises histopatológicas e morfométricas das brânquias e do fígado de guarus expostos a
concentrações subletais de Glifosato (35µg/L) e de AMPA (82µg/L) indicaram que ambos
os órgãos são alterados morfologicamente. As brânquias de peixes expostos aos produtos
testes apresentaram maiores índices de reação para as alterações progressivas tais como
aumento do epitélio interlamelar e fusão parcial e total das lamelas secundárias. O fígado
por sua vez apresentou maiores índices de reação para as alterações regressivas como
esteatose, núcleos picnóticos e necrose. As análises proteômicas mostraram que o
Glifosato induz a expressão diferencial de proteínas hepáticas em P. reticulata. As análises
das imagens dos géis permitiram mensurar 225 spots no grupo controle e 180 spots no
grupo exposto a Glifosato. Desse total, 88 spots foram exclusivos do grupo controle e 43
spots foram exclusivos do grupo tratado. Dos 137 spots pareados entre os grupos controle
e tratado 13 foram regulados negativamente e 8 foram regulados positivamente devido a
exposição subletal ao Glifosato. As alterações encontradas indicam que o Glifosato e o
AMPA, apesar de serem considerados poucos tóxicos por guias que avaliam a toxicidade
de produtos químicos, são promotores de alterações deletérias para a saúde animal,
indicando que há necessidade de estabelecimento de novos parâmetros ou mudança de
conceitos, indicando a necessidade de utilizar vários biomarcadores, além da avaliação da
taxa de mortalidade, para estabelecer um critério mais confiável para parâmetros de
toxicidade.
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Nonionic surfactants : A multivariate studyUppgård, Lise-Lott January 2002 (has links)
In this thesis technical nonionic surfactants are studied using multivariate techniques. The surfactants studied were alkyl ethoxylates (AEOs) and alkyl polyglucosides (APGs). The aquatic toxicity of the surfactants towards two organisms, a shrimp and a rotifer, was examined. The specified effect was lethality, LC50, as indicated by immobilisation. In a comparative study, the LC50 values obtained were used to develop two different types of model. In the log P model the toxicity was correlated to log P alone, while in the multivariate model several physicochemical variables, including log P, were correlated to the toxicity. The multivariate model gave smaller prediction errors than the log P model. Further, the change in reactivity when a surfactant mixture was added to dissolving pulp under alkaline conditions was studied, using the amount of residual cellulose as a measure of the reactivity. Ten AEO/APG mixtures were tested, and the mixture with greatest potential was studied in more detail. An optimum in the amount of added surfactant was found that seems to coincide, according to surface tension measurements, with the CMC.
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Avaliação da presença de metilparabeno e propilparabeno no ambiente aquático e seus potenciais estrogênicos e a toxicidade aguda. / Evaluation of the presence of methylparaben and propylparaben in the aquatic environment and their potential estrogenic and acute toxicity.Carolina Gomes Moreira 14 April 2014 (has links)
Atualmente no cenário mundial a qualidade da água tem gerado muitas
preocupações, pois milhares de produtos sintéticos são produzidos para facilitar
muitas práticas industriais, domésticas e pessoais e com isso diversas substâncias
químicas utilizadas para esses fins são introduzidas no meio ambiente. Os
parabenos são substâncias químicas utilizadas pelas indústrias farmacêuticas, de
alimentos e cosméticos e que cuja função é a conservação, sendo que há muitos
questionamentos em relação a sua segurança, pois alguns relatórios têm mostrado
que a exposição a esses parabenos pode modular ou perturbar o sistema endócrino
e com isso gerar consequências prejudiciais à saúde humana e aos ambientes
aquáticos. Esse estudo teve como objetivo avaliar a presença dos Parabenos
Metilparabeno e Propilparabeno no ambiente aquático e os seus potenciais
estrogênicos e a toxicidade aguda. A metodologia se desenvolveu a partir do ensaio
in vitro YES para a determinação da atividade estrogênica, ensaios de toxicidade
aguda em Daphnia similis e em Aliivibrio fischeri e a quantificação dos parabenos na
água do Rio Maracanã-RJ através da cromatografia líquida acoplada ao
espectrômetro de massa. Os resultados obtidos para a CE50 dos MP e PP, a partir
do ensaio in vitro YES, foi de 18,91 mgL-1 e 7 mgL-1 e a magnitude da resposta foi de
10-5 e 10-4 menos potente que 17ß-estradiol para o MP e o PP, respectivamente. A
partir do ensaio de toxicidade aguda, os valores de CE50 obtidos em Daphnia
similis, foi de 29,42 mgL-1 e 9,94 mgL-1e em Aliivibrio fischeri foi de 3,047 mgL-1 e
1,946 mgL-1, respectivamente, com isso observou-se que o PP é mais tóxicos em
todos os organismos testados, sendo mais tóxicos para um e menos para outros. A
água do Rio Maracanã não foi tóxica para a Daphnia similis em nenhum dos dois
pontos, já para o Aliivibrio fischeri foi tóxica em apenas um ponto. As concentrações
encontradas de MP e PP foram maiores no ponto onde, de acordo com os
parâmetros físico-químicos, a qualidade da água não está dentro dos padrões
exigidos pela legislação, sendo quantificados na ordem de ngL-1, contudo é válido
ressaltar que os DEs não são encontrados no meio ambiente separados, eles
interagem entre si e provocam efeitos aditivos ou sinérgicos, sendo muito difícil de
prever qual o efeito, por isso é importante o conhecimento do potencial estrogênico
das substâncias simples, pois em um estudo com uma matriz ambiental, pode-se
observar se houve algum efeito aditivo ou sinérgico de outras substâncias. / Currently on the world stage water quality has generated many concerns,
because thousands of synthetic products are produced to facilitate many industrial,
domestic and personal practices and thereby various chemicals used for these
purposes are introduced into the environment. Parabens are chemicals used by the
pharmaceutical, food and cosmetic and whose function is to conserve, and there are
many questions regarding its safety , as some reports have shown that exposure to
these parabens can modulate or disrupt endocrine system and thereby generate
harmful consequences for human health and aquatic environments . The aim of this
study was to evaluate the presence of Methylparaben and Propylparaben in the
aquatic environment and their potential estrogenic and acute toxicity. The
methodology developed from the in vitro YES assay for the determination of
estrogenic activity, acute toxicity tests with Daphnia similis and Aliivibrio fischeri and
quantification of parabens in water of Maracanã River RJ by liquid chromatography
coupled with mass spectrometry. The EC50 results for the PP and MP, from the in
vitro YES, was 18,91 mgL -1 and 7 mgL-1 and the magnitude of response was less
potent 10-5 and 10-4 that 17ß - estradiol for MP and PP , respectively. From the acute
toxicity test, the EC50 values obtained in Daphnia similis was 29,42 mgL-1 and 9,94
mgL-1, and Aliivibrio fischeri was 3,047 mgL-1 and 1,946 mgL-1, respectively, with it
was observed that PP is more toxic in all organisms tested, and more toxic to one
and less to others . The water of the Maracanã River was not toxic to Daphnia similis
in either points, since for Aliivibrio fischeri was toxic at only one point. Found
concentrations of MP and PP were higher at the point where, according to the
physico-chemical parameters, water quality is not within the standards required by
legislation and quantified in order ngL-1, however its worth to note that the DEs are
not found in the middle separate environment, they interact with each other and
cause additive or synergistic effects , its very difficult to predict what effect , so its
important to know the estrogenic potential of simple substances , since in a study
with an environmental matrix, one can observe if there were any additive or
synergistic effect of other substances .
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Avaliação da presença de metilparabeno e propilparabeno no ambiente aquático e seus potenciais estrogênicos e a toxicidade aguda. / Evaluation of the presence of methylparaben and propylparaben in the aquatic environment and their potential estrogenic and acute toxicity.Carolina Gomes Moreira 14 April 2014 (has links)
Atualmente no cenário mundial a qualidade da água tem gerado muitas
preocupações, pois milhares de produtos sintéticos são produzidos para facilitar
muitas práticas industriais, domésticas e pessoais e com isso diversas substâncias
químicas utilizadas para esses fins são introduzidas no meio ambiente. Os
parabenos são substâncias químicas utilizadas pelas indústrias farmacêuticas, de
alimentos e cosméticos e que cuja função é a conservação, sendo que há muitos
questionamentos em relação a sua segurança, pois alguns relatórios têm mostrado
que a exposição a esses parabenos pode modular ou perturbar o sistema endócrino
e com isso gerar consequências prejudiciais à saúde humana e aos ambientes
aquáticos. Esse estudo teve como objetivo avaliar a presença dos Parabenos
Metilparabeno e Propilparabeno no ambiente aquático e os seus potenciais
estrogênicos e a toxicidade aguda. A metodologia se desenvolveu a partir do ensaio
in vitro YES para a determinação da atividade estrogênica, ensaios de toxicidade
aguda em Daphnia similis e em Aliivibrio fischeri e a quantificação dos parabenos na
água do Rio Maracanã-RJ através da cromatografia líquida acoplada ao
espectrômetro de massa. Os resultados obtidos para a CE50 dos MP e PP, a partir
do ensaio in vitro YES, foi de 18,91 mgL-1 e 7 mgL-1 e a magnitude da resposta foi de
10-5 e 10-4 menos potente que 17ß-estradiol para o MP e o PP, respectivamente. A
partir do ensaio de toxicidade aguda, os valores de CE50 obtidos em Daphnia
similis, foi de 29,42 mgL-1 e 9,94 mgL-1e em Aliivibrio fischeri foi de 3,047 mgL-1 e
1,946 mgL-1, respectivamente, com isso observou-se que o PP é mais tóxicos em
todos os organismos testados, sendo mais tóxicos para um e menos para outros. A
água do Rio Maracanã não foi tóxica para a Daphnia similis em nenhum dos dois
pontos, já para o Aliivibrio fischeri foi tóxica em apenas um ponto. As concentrações
encontradas de MP e PP foram maiores no ponto onde, de acordo com os
parâmetros físico-químicos, a qualidade da água não está dentro dos padrões
exigidos pela legislação, sendo quantificados na ordem de ngL-1, contudo é válido
ressaltar que os DEs não são encontrados no meio ambiente separados, eles
interagem entre si e provocam efeitos aditivos ou sinérgicos, sendo muito difícil de
prever qual o efeito, por isso é importante o conhecimento do potencial estrogênico
das substâncias simples, pois em um estudo com uma matriz ambiental, pode-se
observar se houve algum efeito aditivo ou sinérgico de outras substâncias. / Currently on the world stage water quality has generated many concerns,
because thousands of synthetic products are produced to facilitate many industrial,
domestic and personal practices and thereby various chemicals used for these
purposes are introduced into the environment. Parabens are chemicals used by the
pharmaceutical, food and cosmetic and whose function is to conserve, and there are
many questions regarding its safety , as some reports have shown that exposure to
these parabens can modulate or disrupt endocrine system and thereby generate
harmful consequences for human health and aquatic environments . The aim of this
study was to evaluate the presence of Methylparaben and Propylparaben in the
aquatic environment and their potential estrogenic and acute toxicity. The
methodology developed from the in vitro YES assay for the determination of
estrogenic activity, acute toxicity tests with Daphnia similis and Aliivibrio fischeri and
quantification of parabens in water of Maracanã River RJ by liquid chromatography
coupled with mass spectrometry. The EC50 results for the PP and MP, from the in
vitro YES, was 18,91 mgL -1 and 7 mgL-1 and the magnitude of response was less
potent 10-5 and 10-4 that 17ß - estradiol for MP and PP , respectively. From the acute
toxicity test, the EC50 values obtained in Daphnia similis was 29,42 mgL-1 and 9,94
mgL-1, and Aliivibrio fischeri was 3,047 mgL-1 and 1,946 mgL-1, respectively, with it
was observed that PP is more toxic in all organisms tested, and more toxic to one
and less to others . The water of the Maracanã River was not toxic to Daphnia similis
in either points, since for Aliivibrio fischeri was toxic at only one point. Found
concentrations of MP and PP were higher at the point where, according to the
physico-chemical parameters, water quality is not within the standards required by
legislation and quantified in order ngL-1, however its worth to note that the DEs are
not found in the middle separate environment, they interact with each other and
cause additive or synergistic effects , its very difficult to predict what effect , so its
important to know the estrogenic potential of simple substances , since in a study
with an environmental matrix, one can observe if there were any additive or
synergistic effect of other substances .
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