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Id: biblio-951821
Autor: Azam, Mudsser; Jan, Arif Tasleem; Kumar, Ashutosh; Siddiqui, Kehkashan; Mondal, Aftab Hossain; Haq, Qazi Mohd. Rizwanul.
Título: Study of pandrug and heavy metal resistance among E. coli from anthropogenically influenced Delhi stretch of river Yamuna
Fonte: Braz. j. microbiol;49(3):471-480, July-Sept. 2018. tab, graf.
Idioma: en.
Projeto: Council of Scientific & Industrial Research.
Resumo: Abstract Escalating burden of antibiotic resistance that has reached new heights present a grave concern to mankind. As the problem is no longer confined to clinics, we hereby report identification of a pandrug resistant Escherichia coli isolate from heavily polluted Delhi stretch of river Yamuna, India. E. coli MRC11 was found sensitive only to tobramycin against 21 antibiotics tested, with minimum inhibitory concentration values >256 µg/mL for amoxicillin, carbenicillin, aztreonam, ceftazidime and cefotaxime. Addition of certain heavy metals at higher concentrations were ineffective in increasing susceptibility of E. coli MRC11 to antibiotics. Withstanding sub-optimal concentration of cefotaxime (10 µg/mL) and mercuric chloride (2 µg/mL), and also resistance to their combinatorial use, indicates better adaptability in heavily polluted environment through clustering and expression of resistance genes. Interestingly, E. coli MRC11 harbours two different variants of blaTEM (blaTEM-116 and blaTEM-1 with and without extended-spectrum activity, respectively), in addition to mer operon (merB, merP and merT) genes. Studies employing conjugation, confirmed localization of blaTEM-116, merP and merT genes on the conjugative plasmid. Understanding potentialities of such isolates will help in determining risk factors attributing pandrug resistance and strengthening strategic development of new and effective antimicrobial agents.
Descritores: Metais Pesados/farmacologia
Farmacorresistência Bacteriana Múltipla
Rios/microbiologia
Escherichia coli/efeitos dos fármacos
Antibacterianos/farmacologia
-Óperon
beta-Lactamases/genética
beta-Lactamases/metabolismo
Testes de Sensibilidade Microbiana
Proteínas de Escherichia coli/genética
Proteínas de Escherichia coli/metabolismo
Escherichia coli/isolamento & purificação
Escherichia coli/enzimologia
Escherichia coli/genética
Índia
Responsável: BR1.1 - BIREME


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Id: biblio-828206
Autor: Lopes Leal, Patrícia; Varón-López, Maryeimy; Gonçalves de Oliveira Prado, Isabelle; Valentim dos Santos, Jessé; Fonsêca Sousa Soares, Cláudio Roberto; Siqueira, José Oswaldo; de Souza Moreira, Fatima Maria.
Título: Enrichment of arbuscular mycorrhizal fungi in a contaminated soil after rehabilitation
Fonte: Braz. j. microbiol;47(4):853-862, Oct.-Dec. 2016. tab, graf.
Idioma: en.
Resumo: Abstract Spore counts, species composition and richness of arbuscular mycorrhizal fungi, and soil glomalin contents were evaluated in a soil contaminated with Zn, Cu, Cd and Pb after rehabilitation by partial replacement of the contaminated soil with non-contaminated soil, and by Eucalyptus camaldulensis planting with and without Brachiaria decumbens sowing. These rehabilitation procedures were compared with soils from contaminated non-rehabilitated area and non-contaminated adjacent soils. Arbuscular mycorrhizal fungi communities attributes were assessed by direct field sampling, trap culture technique, and by glomalin contents estimate. Arbuscular mycorrhizal fungi was markedly favored by rehabilitation, and a total of 15 arbuscular mycorrhizal fungi morphotypes were detected in the studied area. Species from the Glomus and Acaulospora genera were the most common mycorrhizal fungi. Number of spores was increased by as much as 300-fold, and species richness almost doubled in areas rehabilitated by planting Eucalyptus in rows and sowing B. decumbens in inter-rows. Contents of heavy metals in the soil were negatively correlated with both species richness and glomalin contents. Introduction of B. decumbens together with Eucalyptus causes enrichment of arbuscular mycorrhizal fungi species and a more balanced community of arbuscular mycorrhizal fungi spores in contaminated soil.
Descritores: Solo/química
Microbiologia do Solo
Brasil
Micorrizas/classificação
Poluição Ambiental
-Poluentes do Solo/química
Esporos Fúngicos
Proteínas Fúngicas
Contagem de Colônia Microbiana
Metais Pesados/química
Responsável: BR1.1 - BIREME


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Id: lil-788980
Autor: El-Gendy, Mervat Morsy Abbas Ahmed; El-Bondkly, Ahmed Mohamed Ahmed.
Título: Evaluation and enhancement of heavy metals bioremediation in aqueous solutions by Nocardiopsis sp. MORSY1948, and Nocardia sp. MORSY2014
Fonte: Braz. j. microbiol;47(3):571-586, July-Sept. 2016. tab, graf.
Idioma: en.
Resumo: ABSTRACT An analysis of wastewater samples collected from different industrial regions of Egypt demonstrated dangerously high levels of nickel (0.27-31.50 mg L-1), chromium (1.50-7.41 mg L-1) and zinc (1.91-9.74 mg L-1) in the effluents. Alarmingly, these heavy metals are among the most toxic knownones to humans and wildlife. Sixty-nine Actinomycete isolates derived from contaminated sites were evaluated under single, binary, and ternary systems for their biosorption capacity for Ni2+, Cr6+ and Zn2+ from aqueous solutions. The results of the study identified isolates MORSY1948 and MORSY2014 as the most active biosorbents. Phenotypic and chemotypic characterization along with molecular phylogenetic evidence confirmed that the two strains are members of the Nocardiopsis and Nocardia genera, respectively. The results also proved that for both the strains, heavy metal reduction was more efficient with dead rather than live biomass. The affinity of the dead biomass of MORSY1948 strain for Ni2+, Cr6+ and Zn2+ under the optimized pH conditions of 7, 8 and 7, respectively at 40 °C temperature with 0.3% biosorbent dosage was found to be as follows: Ni2+ (87.90%) > Zn2+ (84.15%) > Cr6+ (63.75%). However, the dead biomass of MORSY2014 strain under conditions of pH 8 and 50 °C temperature with 0.3% biosorbent dose exhibited the highest affinity which was as follows: Cr6+ (95.22%) > Ni2+ (93.53%) > Zn2+ (90.37%). All heavy metals under study were found to be removed from aqueous solutions in entirety when the sorbent dosage was increased to 0.4%.
Descritores: Metais Pesados/metabolismo
Nocardia/classificação
Nocardia/metabolismo
-Temperatura
Fatores de Tempo
Poluentes Químicos da Água/metabolismo
Biodegradação Ambiental
RNA Ribossômico 16S/genética
Biomassa
Metais Pesados/toxicidade
Adsorção
Egito
Águas Residuárias/microbiologia
Concentração de Íons de Hidrogênio
Resíduos Industriais
Nocardia/isolamento & purificação
Nocardia/genética
Responsável: BR1.1 - BIREME


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Id: biblio-839359
Autor: Yao, Xie-feng; Zhang, Jiu-ming; Tian, Li; Guo, Jian-hua.
Título: The effect of heavy metal contamination on the bacterial community structure at Jiaozhou Bay, China
Fonte: Braz. j. microbiol;48(1):71-78, Jan.-Mar. 2017. tab, graf.
Idioma: en.
Projeto: program for National Natural Science Foundation of China.
Resumo: Abstract In this study, determination of heavy metal parameters and microbiological characterization of marine sediments obtained from two heavily polluted sites and one low-grade contaminated reference station at Jiaozhou Bay in China were carried out. The microbial communities found in the sampled marine sediments were studied using PCR-DGGE (denaturing gradient gel electrophoresis) fingerprinting profiles in combination with multivariate analysis. Clustering analysis of DGGE and matrix of heavy metals displayed similar occurrence patterns. On this basis, 17 samples were classified into two clusters depending on the presence or absence of the high level contamination. Moreover, the cluster of highly contaminated samples was further classified into two sub-groups based on the stations of their origin. These results showed that the composition of the bacterial community is strongly influenced by heavy metal variables present in the sediments found in the Jiaozhou Bay. This study also suggested that metagenomic techniques such as PCR-DGGE fingerprinting in combination with multivariate analysis is an efficient method to examine the effect of metal contamination on the bacterial community structure.
Descritores: Bactérias
Sedimentos Geológicos/microbiologia
Sedimentos Geológicos/química
Metais Pesados
Biodiversidade
Microbiologia Ambiental
Poluentes Ambientais
Poluição Ambiental
-Bactérias/classificação
Análise por Conglomerados
China
Baías
Meio Ambiente
Responsável: BR1.1 - BIREME


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Id: biblio-1048687
Autor: Nascimento, Velber Xavier; Barros, Alexandre Bomfim; Azevedo, Joaquim Alexandre Moreira; Miranda, Paulo Rogério Barbosa; Costa, João Gomes da.
Título: Bioavailability of heavy metals in mangrove soil in Alagoas, Brazil / Biodisponibilidade de metais pesados em solo de mangue em Alagoas, Brasil
Fonte: Biosci. j. (Online);35(3):818-825, may./jun. 2019. ilus, tab, graf.
Idioma: en.
Resumo: The mangrove forest is an important transitional ecosystem consisted of terrestrial and marine environment located in tropical and subtropical regions with average temperatures above 20 °C. In Alagoas, the mangrove forests are found on the entire coastline from Maragogi to Piaçabuçu. In the last 20 years, due to the pollution of water resources, studies of coastal aquatic ecosystems have been developed. The objective of this study was to analyze the physicochemical properties and determine the levels of heavy metals in mangrove sediments of the Mundaú-Manguaba estuary lagoon complex (MMELC) and Meirim River in Alagoas. Zinc, copper, lead, cadmium and chromium were chosen due to their relationship with sewer, agricultural, and industrial wastes. 22 soil samples were collected in the MMELC and in the Meirim River. The samples were submitted to soil routine analyses of Embrapa. The heavy metals were extracted by the Mehlich-1 method and analyzed by atomic absorption spectrometry. The mean concentrations of these metals in thesediment samples followed the order Mn > Zn >Pb > Cr> Cu >Cd in MMELC and Zn > Mn >Pb > Cr> Cu >Cd in Meirim River. All proposed heavy metals were found in sediments, however, the cadmium levels were above the normal levels proposed by Environment National Council (CONAMA) and Canadian Council of Ministers of the Environment. The study shows that the analysis of sediment can contribute to environmental monitoring actions and development of public policies aimed to controlling the sustainable use of natural resources of the studied areas.

O manguezal é um importante ecossistema de transição entre o ambiente marinho e terrestre, localizado em regiões tropicais e subtropicais com temperaturas médias acima de 20°C. Em Alagoas podemos encontrar florestas de mangue em praticamente todo o litoral desde Maragogi até Piaçabuçu. Nosúltimos 20 anos, a poluição dos recursos hídricos tem levado ao estudo dos ecossistemas aquáticos costeiros, que são importantes para preservação e equilíbrio da vida. O objetivo deste trabalho foi analisar as propriedades físico-químicas e determinar os teores ambientalmente disponíveis de metais nos sedimentos do mangue existente na foz CELMM (e do rio Meirim em Alagoas. Foram escolhidos os metais zinco, cobre, chumbo, cádmio e crômio por estarem ligados aos despejos de esgotos, projetos agropecuários, e fontes industriais. Foram coletadas 22 amostras de solo nos estuários do CELMM e do rio Meirim. As amostras foram submetidas as análises de rotina para solos da Embrapa. As concentrações médias desses metais nas amostras de sedimento seguiram a ordem Mn > Zn >Pb > Cr> Cu >Cd in CELMM e Zn > Mn >Pb > Cr> Cu >Cd no Rio Meirim. Os metais foram extraídos pelo método Mehlich-1 e analisados por meio de espectrometria de absorção atômica. Foram encontrados nos sedimentos todos os metais propostos na pesquisa com destaque para os teores de cádmio detectados em valores absolutos acima de valores considerados normais pelo Conselho Nacional doMeio Ambiente e pelo Canadian Council of Ministers of the Environment em alguns pontos do estuário do rio Meirim. O estudo mostra que a análise dos sedimentos pode, portanto, contribuir para ações de monitoramento ambiental, subsidiando a implantação e desenvolvimento de políticas públicas que visem controlar o usoracional e sustentável dos recursos naturais das áreas do estudas.
Descritores: Metais Pesados
Poluição Ambiental
Áreas Alagadas
-Disponibilidade Biológica
Responsável: BR396.1 - Biblioteca Central


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Calderon, Iracema Mattos Paranhos
Rudge, Marilza Vieira Cunha
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Id: lil-787266
Autor: Motta, Ilse Sodré; Volpato, Gustavo Tadeu; Damasceno, Débora Cristina; Sinzato, Yuri Karen; Vesentini, Giovana; Rudge, Cibele Vieira Cunha; Calderon, Iracema Mattos Paranhos; Kempinas, Wilma De Grava; Odland, Jon Øvid; Rudge, Marilza Vieira Cunha.
Título: Contamination index. A novel parameter for metal and pesticide analyses in maternal blood and umbilical cord
Fonte: Acta cir. bras;31(7):490-497tab, graf.
Idioma: en.
Resumo: ABSTRACT PURPOSE: To evaluate the contamination index of metals and pesticides in pregnant women, and to relate this to perinatal outcomes. METHODS: Descriptive, retrospective, exploratory study, developed from existing secondary data analyses at Level III maternity center. A total of 40 mothers with their newborns (NB), living in a rural area in Botucatu- Brazil and surrounding region. Blood samples from mothers and newborn were collected to determine the total contamination index for metals and pesticides. The concentrations of each metal and each pesticide were determined in blood samples of mothers and their newborns by Rudge's results. After obtaining these concentrations, the total contamination index in mother and NB was calculated, along with its correlation with clinical parameters of NB. RESULTS: There was no correlation (p> 0.05) between maternal contamination index with NB clinical parameters, and NB contamination index versus NB clinical parameters. CONCLUSION: The maternal contamination index of metals and pesticides was not related to perinatal outcomes, but it could be used as baseline parameter in future toxicological studies, regarding to long-term toxic characteristics as persistent organic pollutants, its long half-lives, bioacumulative, and expected to impose serious health effects on humans.
Descritores: Praguicidas/sangue
Peso ao Nascer
Metais Pesados/sangue
Sangue Fetal/química
-Praguicidas/análise
População Rural/estatística & dados numéricos
Fatores Socioeconômicos
Brasil
Gravidez
Substâncias Perigosas/análise
Substâncias Perigosas/sangue
Estudos Retrospectivos
Exposição Materna/efeitos adversos
Metais Pesados/análise
Limites: Humanos
Feminino
Recém-Nascido
Adulto
Adulto Jovem
Responsável: BR1.1 - BIREME


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Id: biblio-1050068
Autor: Algburi, J; Jarrah, N; Mohammed, K; Jaafar, A; Alshabani, M; Almayahi, B.
Título: Evaluation the Health Impact of Some Heavy Metals in Milk from Markets
Fonte: Prensa méd. argent;105(11):849-851, dic2019. tab.
Idioma: en.
Resumo: This study focuses on the heavy metals concentrations (Fe, Cu, Zn, Pb, and Cd) in certain common milk species are collected from Iraqi markets using Flame Atomic Absorption Spectrophotometer-6300 AA, Shimadzu, Japan, respectively. This study shows the pollution in the environment obtained by heavy metals. The results showed that Cr, Cd, Cu, Zn, and Fe were varying according to the order: Zn>Fe>Cr>Cd>Cu. levels of heavy metals were 0.610(Cr), 0.125(Cd), 0.052(Cu), and 6.902(Zn), and 0.759(Fe). All the heavy metals were observed within maximum limit in milk. Overall, the number of analyzed heavy metals and sample size were limited in present study. Keywords: Heavy metals; Milk; Najaf; Flame atomic absorption; Spectrophotometer This study focuses on the heavy metals concentrations (Fe, Cu, Zn, Pb, and Cd) in certain common milk species are collected from Iraqi markets using Flame Atomic Absorption Spectrophotometer-6300 AA, Shimadzu, Japan, respectively. This study shows the pollution in the environment obtained by heavy metals. The results showed that Cr, Cd, Cu, Zn, and Fe were varying according to the order: Zn>Fe>Cr>Cd>Cu. levels of heavy metals were 0.610(Cr), 0.125(Cd), 0.052(Cu), and 6.902(Zn), and 0.759(Fe). All the heavy metals were observed within maximum limit in milk. Overall, the number of analyzed heavy metals and sample size were limited in present study
Descritores: Espectrofotometria Atômica
Espectrofotômetros de Chama
Metais Pesados/toxicidade
Leite
Responsável: AR392.1 - Biblioteca


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Id: lil-633154
Autor: Peluso, Fabio; González Castelain, José; Othax, Natalia; Rodríguez, Lorena.
Título: Riesgo sanitario por sustancias tóxicas en aguas superficiales de Tres Arroyos, Argentina / Health risk by toxic substances in freshwater of Tres Arroyos, Argentina / Risco sanitário por substâncias tóxicas em águas superficiais de Tres Arroyos, Argentina
Fonte: Acta bioquím. clín. latinoam;45(2):311-321, abr.-jun. 2011. mapas, tab.
Idioma: es.
Projeto: ANPCyT; . Universidad Nacional del Centro de la Prov. de Buenos Aires; . Comisión de Investigaciones Científicas de la Prov. De Buenos Aires; . Municipalidad de Azul. AR PID 35765 Desarrollo de criterios y pautas para el gerenciamiento de recursos hídricos en áreas de llanura.
Resumo: En cursos de agua del partido de Tres Arroyos (provincia de Buenos Aires, Argentina) se encontraron sustancias tóxicas (metales pesados, nitratos, nitritos, fluoruros, sustancias fenólicas y pesticidas organoclorados). El objetivo del trabajo fue estimar el riesgo sanitario para el baño recreativo en esas aguas. El análisis se basó en el modelo USEPA probabilístico para riesgo agregado y acumulativo, tanto para efectos no carcinogenéticos (ENC) como carcinogenéticos (EC), considerando la ingesta accidental de agua y el contacto dérmico. Se planteó un escenario de exposición basado en datos propios y de la literatura para un niño de 10 años como representativo de la población expuesta. Los resultados indican que no existiría riesgo relevante para la actividad recreativa para las concentraciones consideradas. De todos los cuerpos de agua el de mayor riesgo es el Arroyo Claromecó, pero sólo alcanza al 20% del valor limitante. Los metales contribuyen con un 82 y 99% del riesgo total acumulado por ENC y EC, respectivamente, seguidos por las sustancias inorgánicas. Y de los metales, el mayor contribuyente al riesgo es el arsénico, quien aporta el 78 y 99% del riesgo agregado y acumulado por todas las sustancias para ENC y EC, respectivamente.

Toxic substances (heavy metals, nitrate, nitrite, fluoride, phenolic substances and organochlorine pesticides) were detected in Tres Arroyos county freshwaters (Buenos Aires province, Argentina). The aim of this study was estimate the human health risk (HR) associated with these substances during recreational bathing. The probabilistic HR assessment was based on aggregated and cumulative USEPA models. Cancer (CE) and non-cancer (NCE) risk were estimated for accidental drinking and dermal contact during the recreational activity. The exposure scenario considered was based on own and literature data, and a ten year-old child was selected as representative of the exposed population. The results indicated that surveyed substances do not generate any health risk for recreational bathing with direct contact at the specified concentrations and exposure conditions. Claromecó creek station was the riskiest point of whole water bodies, but it reaches only 20% of the limitating value. Metals were the major contributors to overall aggregated and cumulative risk (82% for NCE and 99% for CE), followed by inorganic substances. Arsenic was the most dangerous metal, responsible for the 78 and 99% of the aggregate and cumulative risks for all substances for NCE and CE, respectively.

Em cursos d´água da localidade de Tres Arroyos (Província de Buenos Aires, Argentina) foram encontradas substâncias tóxicas (metais pesados, nitratos, nitritos, fluoretos, substâncias fenólicas e pesticidas organoclorados). O objetivo do trabalho foi calcular o risco sanitário para o banho com fins recreativos nessas águas. A análise foi realizada com base no modelo USEPA probabilístico para risco agregado e acumulativo, tanto para efeitos não carcinogênicos (ENC) como carcinogênicos (EC), considerando a ingestão acidental de água e o contato dérmico. Foi apresentado um cenário de exposição com base em dados próprios e da literatura para um menino de dez anos como representativo da população exposta. Os resultados indicam que não existiria risco relevante para a atividade recreativa para as concentrações consideradas. De todos os corpos de água aquele de maior risco é o Arroyo Claromecó mas só atinge 20% do valor limitante. Os metais contribuem com 82 e 99% do risco total acumulado por ENC e EC, respectivamente, seguidos pelas substâncias inorgânicas. E dos metais, o maior contribuinte ao risco é o arsênico, que oferece 78 e 99% do risco agregado e acumulado por todas as substâncias para ENC e EC, respectivamente.
Descritores: Argentina
Arsênico
Águas Superficiais
Substâncias Tóxicas
Metais Pesados
Risco à Saúde Humana
-Arsênico/análise
Arsênico/toxicidade
Qualidade da Água
Substâncias Perigosas/toxicidade
Estatística como Assunto
Metais Pesados/análise
Intoxicação por Metais Pesados
Intoxicação por Metais Pesados/diagnóstico
Tipo de Publ: Relatório Técnico
Metanálise
Ensaio Clínico Controlado
Responsável: AR1.2 - Instituto de Investigaciónes Epidemiológicas


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Id: biblio-889192
Autor: Strahsburger, Erwin; Zapata, Felipe; Pedroso, Inti; Fuentes, Derie; Tapia, Paz; Ponce, Raul; Valdes, Jorge.
Título: Draft genome sequence of Exiguobacterium aurantiacum strain PN47 isolate from saline ponds, known as "Salar del Huasco", located in the Altiplano in the North of Chile
Fonte: Braz. j. microbiol;49(1):7-9, Jan.-Mar. 2018.
Idioma: en.
Projeto: Academic Vice Rectory of Arturo Prat University; . International Centers of Excellence.
Resumo: ABSTRACT In this report, we present a draft genome of 2,886,173 bp of an Exiguobacterium aurantiacum strain PN47 isolate from the sediment of a saline pond named "Salar del Huasco" in the Altiplano in the North of Chile. Strain PN47 encodes adaptive characteristics enabling survival in extreme environmental conditions of high heavy metal and salt concentrations and high alkalinity.
Descritores: Bacillaceae/isolamento & purificação
Bacillaceae/genética
Tanques/microbiologia
Genoma Bacteriano
-Filogenia
Bacillaceae/classificação
Bacillaceae/metabolismo
DNA Bacteriano/genética
Sequência de Bases
Cloreto de Sódio/análise
Cloreto de Sódio/metabolismo
Tanques/química
Chile
Metais Pesados/análise
Metais Pesados/metabolismo
Responsável: BR1.1 - BIREME


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Id: biblio-837852
Autor: Biruk, Lucía Nadia; Moretton, Juan; Filippetto, Javier; Etcheverry, Jimena; Weigandt, Cristian; Fabrizio de Iorio, Alicia; Magdaleno, Anahí.
Título: Evaluación genotóxica de sedimentos de la cuenca Matanza-Riachuelo bajo la influence de distintos usos del suelo / Genotoxic evaluation of sludge from Matanza-Riachuelo basin under the influence of different uses of land
Fonte: Acta toxicol. argent;24(1):33-47, jul. 2016. mapas, tab.
Idioma: es.
Projeto: Universidad de Buenos Aires. UBACyT.
Resumo: El Río Matanza-Riachuelo y sus afluentes atraviesan zonas con diferente grado de contaminación generada por las actividades agrícola-ganaderas, urbana e industrial. Los contaminantes que llegan al agua y son depositados en los sedimentos pueden ser liberados nuevamente al agua generando efectos tóxicos y/o genotóxicos sobre los organismos acuáticos. El objetivo de este trabajo fue analizar la genotoxicidad de muestras de sedimentos de la cuenca Matanza-Riachuelo obtenidas de zonas con diferentes usos del suelo. Se seleccionaron cuatro sitios de muestreo. Se utilizaron 2 métodos de extracción de contaminantes (agitación y sonicación), 2 solventes orgánicos (metanol y diclorometano) y 2 solventes inorgánicos (agua y solución ácida), obteniéndose un total de 5 extractos para cada muestra. Se realizaron mediciones de metales pesados e hidrocarburos aromáticos policíclicos (HAPs) mediante espectrofotometría de absorción atómica y CG/MS, respectivamente. La genotoxicidad se evaluó mediante el test de Ames con 2 cepas de Salmonella typhimurium (TA98 y TA100), con y sin fracción microsomal S9, y el test de Allium cepa. De los cuatro sitios estudiados, los sedimentos del Riachuelo mostraron mayores concentraciones de metales pesados y HAPs. Para el test de Ames, sólo los extractos obtenidos en diclorometano resultaron genotóxicos para la TA100 +S9 mix. Tanto los extractos inorgánicos como los orgánicos fueron citotóxicos y genotóxicos para A. cepa. Se observó una correlación negativa entre algunos compuestos HAPs y la frecuencia de micronúcleos, indicando la presencia de efectos antagónicos con otros compuestos genotóxicos. Los extractos con mayor efecto tóxico y genotóxico fueron los obtenidos con diclorometano y solución ácida. Este estudio mostró que los contaminantes orgánicos e inorgánicos extraídos de muestras de sedimento de la Cuenca Matanza-Riachuelo, con diferente grado de impacto, presentan un potencial riesgo tóxico y genotóxico para el ecosistema acuático.

The Matanza-Riachuelo River and its tributaries traverse areas with different degrees of contamination due to farming, urban and industrial activities. The pollutants entering the water are deposited in sediments, and can be released back into the water producing toxic and/or genotoxic effects on aquatic organisms. The aim of this study was to analyze the genotoxicity of sediment samples from the Matanza-Riachuelo Basin with different land uses. Four sampling sites according to the characteristics of land use were selected. Two methods of extraction (stirring and sonication), two organic solvents (methanol and dichloromethane) and two inorganic solvents (water and acid solution) were used, yielding a total of 5 extracts for each sample. Measurements of heavy metals and polycyclic aromatic hydrocarbons (PAHs) by atomic absorption spectrophotometry and GC/MS, respectively were performed. Genotoxicity was assessed using the Ames test with 2 strains of Salmonella typhimurium (TA98 and TA100) with and without S9 microsomal fraction, and the Allium cepa test. Taking into account the four sites, sediments from Riachuelo showed higher concentrations of heavy metals and PAHs. Only the dichloromethane extracts were genotoxic to the Ames test using the TA100 strain +S9 the mix. Both organic and inorganic extracts were cytotoxic and genotoxic to A. cepa. A negative correlation between some PAHs compounds and micronucleus frequency were observed, indicating the presence of antagonistic effects with other genotoxic compounds in samples. The extracts with high toxic and genotoxic effects were obtained with dichloromethane and acid solution. This study showed that organic and inorganic contaminants extracted from sediment samples from the Matanza-Riachuelo Basin, with varying degrees of impact, have potential toxic and genotoxic risk to the aquatic ecosystem.
Descritores: Hidrocarbonetos Policíclicos Aromáticos/isolamento & purificação
Sedimentos/análise
Metais Pesados/isolamento & purificação
Genotoxicidade
-Espectrofotometria Atômica/métodos
Poluição de Rios/análise
Cromatografia Gasosa/métodos
Testes de Mutagenicidade/métodos
Responsável: AR1.2 - Instituto de Investigaciónes Epidemiológicas



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