ABSTRACT
Introduction: The bivalve Semimytilus patagonicus is a potentially useful bioindicator because of its feeding mechanism, and the worm Pseudonereis gallapagensis is also interesting as a bioindicator because it is benthonic, abundant, and a food source for the squid Doryteuthis gahi. However, their sensitivity to contaminants has not been sufficiently studied. Objective: To test the usefulness of the mussel Semimytilus patagonicus and the polychaete Pseudonereis gallapagensis as ecotoxicological tools for detergents in the marine environment. Methods: We used 120 individuals of S. patagonicus from Miraflores and 120 of P. gallapagensis from Barranco (both near the city of Lima, Peru). For the bioassays, we used two anionic detergents (active ingredient, ai, Sodium Dodecylbenzene Sulfonate). For S. patagonicus, with an average valve length of 32.3 ± 6.4 mm, we tested "Double power Ariel®" (90 %) at concentrations of 17.5, 35, 70 and 140 mg ai l-1, evaluated after 48 and 72 h of exposure; and for P. gallapagensis, with a total body length of 20.4 ± 8.8 mm, we tested "Caricia®" at 62.5, 125, 250, 500 and 1 000 mg of ai l-1 at 24, 48 and 72 h of exposure. Results: The LC50 values (Mean Lethal Concentration) were 34.95 mg ia l-1 for S. patagonicus and 102.48 mg ia l-1 for P. gallapagensis at 72 h of exposure. The detergents were toxic for S. patagonicus and slightly toxic for P. gallapagensis. The risk classification for S. patagonicus is "harmful" and for P. gallapagensis "not classifiable". Conclusions: These two bioindicators allow evaluating the acute toxicity of SDBS-based commercial detergents in the marine aquatic environment.
Introducción: El bivalvo Semimytilus patagonicus es un bioindicador potencialmente útil por su mecanismo de alimentación, y el gusano Pseudonereis gallapagensis también es interesante como bioindicador por ser bentónico, abundante y fuente de alimento para el calamar Doryteuthis gahi. Sin embargo, su sensibilidad a los contaminantes no ha sido suficientemente estudiada. Objetivo: Probar la utilidad del mejillón S. patagonicus y el poliqueto P. gallapagensis como herramientas ecotoxicológicas para detergentes en el medio marino. Métodos: Se utilizaron 120 individuos de S. patagonicus de Miraflores y 120 de P. gallapagensis de Barranco (ambos cerca de la ciudad de Lima, Perú). Para los bioensayos se utilizaron dos detergentes aniónicos (ingrediente activo, ia, dodecilbenceno sulfonato de sodio). Para S. patagonicus, con una longitud valver promedio de 32.3 ± 6.4 mm, probamos Ariel Doble Poder® (90 %) a concentraciones de 17.5, 35, 70 y 140 mg·ia·l-1, evaluadas a las 48 y 72 h de exposición; y para P. gallapagensis, con una longitud corporal total de 20.4 ± 8.8 mm, probamos Caricia® a 62.5, 125, 250, 500 y 1 000 mg·ia·l-1 a las 24, 48 y 72 h de exposición. Resultados: Los valores de CL50 (Concentración Letal Media) fueron de 34.95 mg·ia·l-1 para S. patagonicus y 102.48 mg·ia·l-1 para P. gallapagensis a las 72 h de exposición. Los detergentes fueron tóxicos para S. patagonicus y levemente tóxicos para P. gallapagensis. La clasificación de riesgo para S. patagonicus es "nocivo" y para P. gallapagensis "no clasificable". Conclusiones: Estos dos bioindicadores permiten evaluar la toxicidad aguda del detergente comercial a base de SDBS en el ambiente acuático marino.
Subject(s)
Animals , Polychaeta/microbiology , Bivalvia/microbiology , Detergents/toxicity , Peru , Coastal PollutionABSTRACT
Aim: The study was aimed to determine the toxicity of paraquat dichloride and lambda-cyhalothrin on phosphate solubilizing bacteria, Pantoa dispersa in aquatic ecosystems.Study Design: This study employs randomized block design, statistical analysis of the data and interpretation.Place and Duration of the Study: Soil sample was collected from the root nodules of leguminous plants in a sterile polythene bag from the Elele, in Etche L.G.A, Rivers State. The fresh water sample was collected from Bane town in Khana L.G.A, brackish water sample was collected from Choba river in Obio/Akpor L.G.A while the marine water was collected from Bonny River of Bonny L.G.A., all of Rivers State, Nigeria. The samples were collected aseptically and transported in an ice-pack immediately to the Rivers State University, Microbiology laboratory for analysis. The study lasted for three months.Methodology: The bacterium, Pantoa dispersa was isolated and identified based on conventional and molecular characterization from water and soil samples. Different concentrations (3.13%, 6.25, 12.50, 25.00%, 50.00% and 75.00%) and the control (0%) of the herbicide (paraquat dichloride) and insecticide, Lambda-cyhalothrin were prepared using fresh, brackish and marine water samples and 10ml of the test organism, Pantoa dispersa was introduced and the survival count was determined at 0, 4hr, 8hr, 12hr and 24hr. The Mean Lethal Concentration (LC50) of the insecticide and herbicide on Pantoa dispersa in the three aquatic ecosystem was determined.Results: The LC50 of the herbicide (Paraquat dichloride) was recorded as 15.8% in brackish water, 17.37% in fresh water and 27.44% in marine water. While the LC50 of the insecticide, Lambda-cyhalothrin to Pantoa dispersa was 26.84% in fresh water, 27.26% in brackish water and 32.33% in marine water.Conclusion: From the study, the herbicide, Paraquat dichloride was more toxic in the three aquatic ecosystems compared to the insecticide, Lambda-cyhalothrin. The use of these agrochemicals should be monitored as they result in the mortality of beneficial soil bacteria like Pantoa dispersa which is phosphate solubilizing bacteria in aquatic ecosystems.
ABSTRACT
RESUMEN El Paraquat es un herbicida utilizado en la actividad agropecuaria para controlar hierbas, su modo de acción es por medio de contacto y no selectivo. Debido a su alta solubilidad en agua y baja volatilidad representa un riesgo potencial para organismos acuáticos, principalmente los que son cultivados con aguas superficiales que reciben impacto de la actividad agrícola. La tilapia Oreochromis niloticus y el langostino Macrobrachium olfersii son organismos de importancia comercial para la industria acuícola del estado de Veracruz, México. El objetivo de este estudio fue determinar la Concentración Letal Media (CL50) del herbicida Dasurquat® (ingrediente activo Paraquat) a través de un bioensayo de toxicidad aguda (96 horas). Se utilizaron como especímenes de prueba a juveniles de tilapia O. niloticus (peso promedio = 10 mg, longitud total= 8,75 mm) y otro el ensayo fue con poslarvas de langostino M. olfersii (peso promedio = 5 mg, longitud total= 5,72 mm). Se emplearon cinco concentraciones (5, 10, 20, 40 y 80 μL-1 para el bioensayo con juveniles de tilapia; para el bioensayo con poslarvas de langostino las concentraciones fueron 0,1, 0,2, 0,5, 0,7 y 1 μL-1). El diseño experimental consideró un control negativo, con dos repeticiones y dos réplicas por cada tratamiento. El análisis de datos se realizó con el método Probit para determinar la CL50 a 96 horas, se obtuvo un valor para juveniles de O. niloticus de 17,49 μL-1 con intervalo de confianza (95 %) con límite inferior de 13,75 μL-1 y límite superior 22,25 μL-1, para las larvas de M. olfersii se obtuvo un valor de 0,31 μL-1 con intervalo de confianza (95 %) con límite inferior de 0,26 μL-1 y límite superior 0,35 μL-1. El análisis de varianza demostró que no existió diferencia estadística significativa (p > 0.05) entre las réplicas de los tratamientos. Se concluye que es necesario continuar con estudios para evaluar su toxicidad en organismos acuáticos debido al amplio uso de este herbicida en la actividad agropecuaria, y determinar su riesgo para otras actividades productivas además de la acuicola.
ABSTRACT Paraquat is an herbicide used in the agricultural industry for weed and undergrowth control, its mode of action is by contact and nonselective. Due to its high-water solubility and low volatility, it represents a potential risk for non-target organisms. Oreochromis niloticus tilapia and the prawn Macrobrachium olfersii are important commercial species for Veracruz's aquaculture industry. The objective of this study was to determine the Mean Lethal Concentration (LC50) of the herbicide Dasurquat® (active ingredient Paraquat) through an acute toxicity bioassay (96 hours). Juvenile O. niloticus (average weight = 10 mg, total length = 8.75 mm) and juvenile M. olfersii postlarvae (average weight = 5 mg, total length = 5.72mm) were used as test specimens. Five herbicide concentrations (5, 10, 20, 40 and 80 μL-1 for tilapia and 0.1, 0.2, 0.5, 0.7 y 1 μL-1 for prawn) were applied. The experimental design considered a negative control, with two replications and two replicates for each treatment. Probit analysis determined that the LC50 at 96 hours for O. niloticus was 17.49 μL-1, with a lower 95 % confidence limit of 13.75 μL-1 and an upper limit of 22.25 μL-1, whereas for M. olfersii the LC50 at 96 hours was 0.31 μL-1, with a lower 95 % confidence limit of 0.26 μL-1 and an upper limit of 0.35 μL-1. The analysis of variance showed that there was no significant statistical difference (p > 0.05) between the replicates of the treatments. It is concluded that it is necessary to continue evaluating its toxicity in aquatic organisms due to the wide use of this herbicide in Veracruz's agricultural activity, to determine its potential risk to other activities.
ABSTRACT
@#Rhipicephalus sanguineus, commonly known as brown dog tick is a widespread species with considerable public health and economic importance. Tremendous efforts were performed to control the tick populations with the concern of resistance build-up and environmental issues. Alternative towards microbial control thus emerged as one option to reduce tick populations. In this study, the ovicidal efficacy of a native isolate entomopathogenic hyphomycetes fungi, Metarhizium anisopliae strain HSAH5 was evaluated against eggs of R. sanguineus. Spray applications with three different conidial concentrations of 105, 106 and 107 conidia mL-1; 40 ppm of Flumethrin and a negative control. The M. anisopliae strain was found highly virulent to R. sanguineus eggs by reducing the hatching percentages to ≈30% compared with 8.9% in Flumethrin eggs. The result showed a significantly higher mortality in M. anisopliae group than those of the control groups (F = 42.08, df = 32, P < 0.001) at 30 days post-infection. However, there are no significant differences within the M. anisopliae group, in which the mortality between different conidial concentrations is almost the same. The estimated LC50 of M. anisopliae against eggs of R. sanguineus is 1.36 × 103 conidia ml-1. Thus, these results suggest M. anisopliae strain HSAH5 could be a potential biocontrol agent of R. sanguineus in the integrated approach to managing ticks in the residential landscape by targeting on the eggs.
ABSTRACT
This study was performed to determine the heavy metal accumulation concentrations in different tissues ofthe selected brackish water fish Mugil cephalus. The fishes were exposed to sub-lethal concentrations of leadacetate (Pb (C2H3O2)2) for 96 hour, and LC50 value was found to be 18.7 ppm. The one-tenth of (1/10) LC50(1.89 ppm) value was selected as a lower sub-lethal concentration for the exposure period of 30 days. Theorgans of fish, namely, gills, liver, and muscle were carefully separated through the dissection from fish forthe determination of heavy metal using Absorption Spectrophotometer (Perkin Elmer Analyst-400, USA). Theresults reveal that the low concentration of lead (1.89 ppm) exhibits a maximum level of accumulation in theliver (0.746 ± 0.0033 μg/g), gills (0.672 ± 0.0069 μg/g), and muscle (0.254 ± 0.0052 μg/g) tissues of 30 daysexposed. The result of the present investigation also reveals that the time-dependent lead accumulation indifferent tissues of fish M. cephalus exposed to different sub-lethal concentration of the lead. These findingsextend for future studies on the evaluation of lead accumulation tendency in relation to the eco-toxicologicalobservations for heavy metals risk assessment.
ABSTRACT
This study aimed to evaluate the cytotoxicity and genotoxicity and determine the LC50 concentration of powdered infant formulas widely marketed in South American countries. To this, milk samples, called as A, B, C and D, were analyzed in root meristem cells of Allium cepa, at concentrations of 0.075; 0.15 and 0.30 g mL-1, for 24 and 48 hours; and through cell viability in culture of normal line cells, via MTT test, for 24 hours, in the concentrations 0.018; 0.0375; 0.075 and 0.15 g mL-1. In A. cepa, all dairy products in the three concentrations caused significant inhibition of cell division in the meristems within the first 24 hours of exposure. In the in vitro evaluation, all milk formulas at 0.15 g mL-1, as well as milk A at a concentration of 0.037 g mL-1, C at 0.075 g mL-1 and D at 0.037 g mL-1, significantly reduced the cellular viability of the cell culture exposed to the foods studied, being potentially toxic. The milk A was considered the most toxic, with LC50 of 0.031 g mL-1, and B as the least toxic, with LC50 of 0.15 g mL-1. Therefore, the milk evaluated caused significant instability in cells of the test systems used and were characterized as cytotoxic.
Subject(s)
Humans , Infant , Child , Cytotoxins/analysis , Cytotoxins/chemistry , Cell Survival , Breast-Milk Substitutes , DNA DamageABSTRACT
Abstract Deionized ammonium (NH3) acute toxicity (LC50-96h) in Patagonian blenny juveniles (Eleginops maclovinus) was assessed. Concentrations of deionized ammonium in salt water were prepared by using 24.09 ± 2.1 g ammonium chloride (NH4Cl). Fish were exposed in triplicates to different ammonium concentrations: 0.05; 0.094; 0.175; 0.325 and 0.605 mg NH3 L-1. Additionally, a control group was included. Experimental fish were kept at a photoperiod of 16:8h. Average temperatures were 16.24 ± 1.40 °C. Oxygen concentration was 7.16 ± 0.40 mg L -1. Water pH was 7.89 ± 0.2. LC50-96 h, was estimated by using Probit statistical method (95% intervals) using EPA software (1993). Juveniles of E. maclovinus showed a LC50-96h of 0.413mg NH3 L-1 value, different from most marine species. This study presents the first record of ammonium toxicity in marine species of Chile.
Resumo A toxicidade aguda (LC50-96h) de amônia deionizada (NH3 ) em Babosas-da-Patagônia (Eleginops maclovinus) juvenis foi avaliada. As concentrações de sal de amônia deionizada em água foram preparados com 24,09 ± 2,1 g de cloreto de amônio (NH4Cl). Os peixes foram expostos em triplicata a diferentes concentrações de amônia: 0,05; 0,094; 0,175; 0,325 e 0,605 mg L-1 de NH3. Além disso, um grupo de controle foi incluído. Peixes experimentais foram mantidos em fotoperíodo de 16: 8h. As temperaturas médias foram 16,24 + 1,40 °C. A concentração de oxigênio foi 16.24 +1.40°C mg L-1 . O pH da água foi de 7,89 + 0,2. h LC50-96h, foi estimada usando o método estatístico de Probit (intervalos de 95%) usando o software EPA (1993). E. maclovinus juvenis apresentaram uma LC 50-96h de 0.413mg NH3 L-1 valor diferente da maioria das espécies marinhas. Este estudo apresenta o primeiro registro de toxicidade amónio em espécies marinhas do Chile.
Subject(s)
Animals , Perciformes/growth & development , Perciformes/physiology , Ammonium Compounds/toxicity , Fish Diseases/chemically induced , Temperature , Water Pollutants, Chemical/toxicity , ChileABSTRACT
Introducción: Diversos estudios han demostrado el efecto del Cd sobre la mortalidad y otras respuestas fisiológicas de diversas especies de poliquetos. Objetivo: Evaluar el efecto tóxico del Cd en la mortalidad de adultos de Polydora sp. como especie prueba para estudios ecotoxicológicos. Métodos: Los especímenes fueron recolectados en el humedal costero Poza de la Arenilla, Callao, Peru. Los organismos fueron aclimatados durante dos semanas con agua de mar y sedimento y posteriormente, tres días en agua de mar, con 30 ‰ de salinidad y temperatura entre 20 a 22 °C. Los organismos se expusieron a las concentraciones nominales 75, 11.25, 1.69, 0.25; 0.04 mg/L de Cd y un control. Se analizaron tres réplicas de diez individuos por tratamiento durante 72 horas para registrar mortalidad. Se aplicaron las pruebas de Kruskal-Wallis y de U-Man Whitney para detectar las diferencias significativas entre tratamientos. Resultados: El efecto adverso del Cd sobre la mortalidad fue mucho más evidente en los tratamientos de 11.25 y 75 mg/L a partir de las primeras 24 horas de exposición. La concentración letal media de Cd a 72h fue de 2.59 mg/L. Conclusiones: La CL50 está en el mismo orden de magnitud de otras especies de poliquetos. Este es el primer estudio ecotoxicológico en Perú con poliquetos en condiciones de laboratorio. Se sugiere la utilización de Polydora sp. como especie prueba en experimentos de ecotoxicología, utilizando concentraciones nominales subletales de Cd que no superen los 1.6 mg/L para la observación de varias respuestas fisiológicas.
Introduction: Several studies have demonstrated the effect of Cd on mortality and other physiological responses of some polychaete species. Objective: To evaluate the toxic effect of Cd on adults mortality of Polydora sp as a test species for ecotoxicological studies. Methods: The specimens were collected in the coastal wetland of Poza de la Arenilla, Callao, Peru. The organisms were acclimatized for two weeks with seawater and sediment and then, three days in seawater, with 30 ‰ of salinity and temperature between 20 to 22 °C. The organisms were exposed to the nominal concentrations 75, 11.25, 1.69, 0.25; 0.04 mg/L of Cd and a control. Three replicates of ten individuals per treatment were analyzed for 72 hours to register mortality. The Kruskal-Wallis and U-Man Whitney tests were applied to detect significant differences among treatments. Results: The adverse effect of Cd on mortality was much more evident in the treatments of 11.25 and 75 mg/L after the first 24 hours of exposure. The mean lethal concentration of Cd at 72h was 2.59 mg/L. Conclusions: The LC50 is in the same order of magnitude as other polychaete species. This is the first ecotoxicological study in Peru using polychaetes under laboratory conditions. It is suggested the use of Polydora sp as a test species in ecotoxicology experiments, using nominal sublethal concentrations of Cd not exceeding 1.6 mg/L. for the observation of several physiological responses.
ABSTRACT
Ananas comosus, conocido popularmente como piña, tiene una anatomía de planta bien definida y numerosos fitoquímicos farmacológicamente activos. Algunos de éstos son responsables del potencial antimicrobiano de la especie, que ha sido ampliamente estudiado dada la resistencia bacteriana a los antibióticos actualmente utilizados. Teniendo esto en cuenta, se define que la característica principal de un medicamento es la ausencia de efectos tóxicos, por lo tanto, es necesario buscar datos sobre la toxicidad de A. comosus, colaborando para su posible uso como fármaco. Comparando extractos hidroalcohólicos de las hojas de la corona, cáscara y pulpa de la infrutescencia, fue posible determinar que los tres extractos probados no son tóxicos, siendo el de menor toxicidad para Artemia salina Leach (extracto de hojas con CL50 igual a 994 μg/mL) y a sangre de cordero (extracto de pulpa con porcentaje de hemólisis igual a 0,83%). Los estudios sobre principios y metodologías similares a los utilizados aquí han encontrado resultados comparables que indican la baja toxicidad de la planta. Estos resultados aportan a las investigaciónes que promueven el uso de la piña como agente fitoterapéutico y reafirman su presencia en el Sistema Único de Salud de Brasil.
Ananas comosus, popularly known as pineapple, has well defined plant anatomy and numerous pharmacologically active phytochemicals. Some of these are responsible for the species antimicrobial potential, which has been widely studied given the bacterial resistance to the currently used antibiotics. Considering this, it is defined that the main characteristic of a drug is the absence of toxic effects, thus, there is a need to seek data regarding the toxicity of A. comosus, collaborating for its possible use as a drug. Comparing hydroalcoholic extracts from the crown leaves, skin and pulp of the infructescence, it was possible to determine that the three tested extracts are non-toxic, being the one with the lowest toxicity to Artemia salina Leach (leaves extract with LC50 equal to 994 μg/mL) and to lamb's blood (pulp extract with percentage of haemolysis equal to 0.83%). Studies concerning principles and methodologies similar to those used here have found comparable results stating the low toxicity of the plant. These results contribute to the research that promotes the use of pineapple as a phytotherapeutic agent and reaffirms its presence in the Brazilian Unified Health System.
Subject(s)
Toxicity Tests, Acute/methods , Ananas/toxicity , Plants, Medicinal/adverse effects , Brazil , Erythrocytes/drug effectsABSTRACT
This study aimed to evaluate the effects of three solvent extractors (water, ethanol and hexane) of grounded seeds of soursop, Annona muricata L. (Annonaceae), in the mortality, biology and oviposition of Plutella xylostella L. (Lepidoptera: Plutellidae). The results showed that the LC50 and LC99 were 0.0133 and 0.084%, 0.025% and 0.196%, 2.33 and 35.22% for the ethanolic, hexanic and aqueous extracts, respectively. The organic extracts affected only the larval phase and reduced viability in more than 60%, but did not affect pupal stage of the remaining larvae. Furthermore, the ethanolic extract at lethal concentraction also affected negatively the embryonic phase. The results lead to the conclusion that the ethanolic extract of soursop grounded seeds is a viable alternative to control diamondback moth on vegetables.
O presente trabalho teve como objetivo avaliar o efeito de extratos de sementes de graviola, Annona muricata L. (Annonaceae) obtidos com diferentes solventes sobre Plutella xylostella L. (Lepidoptera: Plutellidae). Foram estimadas as concentrações letais de três solventes extratores (água, hexano e etanol) e seus efeitos na biologia e oviposição. Os valores estimados das concentrações letais foram de 0,013 e 0,084%; 0,025 e 0,196%; 2,33 e 35,22%, para as CL50 e CL99 do extrato etanólico, hexânico e aquoso, respectivamente. Os extratos orgânicos afetaram apenas a fase larval e reduziu a viabilidade em mais de 60%, mas não afetou a fase pupal das lagartas remanescentes. Além disso, o extrato etanólico na concentração letal se mostrou eficiente afetando negativamente a fase embrionária. Conclui-se que o extrato etanólico da graviola é uma alternativa viável no controle da traça.
Subject(s)
Plant Extracts , Annona/toxicity , LepidopteraABSTRACT
RESUMEN El insecticida cipermetrina (CY) es usado en la agricultura para el control de plagas; sin embargo, por su acción neurotóxica puede afectar organismos no blanco como los anuros. El objetivo del trabajo fue determinar la toxicidad (concentración letal media: CL50, y algunos efectos subletales: retrasos en el desarrollo, capacidad de natación y longitud total de las larvas) del insecticida CY (Cypermon® 20EC) expuesto durante 96 horas en embriones y renacuajos de cuatro especies de anuros bajo pruebas de laboratorio y microcosmos. Los embriones de Rhinella humboldti fueron los más sensibles en condiciones de laboratorio (CL50= 6,27 mg/L) y Boana xerophylla en microcosmos (CL50= 88,32 mg/ha), mientras que los de Engystomops pustulosus fueron los más resistentes (laboratorio: CL50= 1 1,80 mg/L; microcosmos: CL50= 1 12,37 mg/ha). Rhinella marina mostró una sensibilidad intermedia. En los renacuajos no fue posible calcular los valores CL50 debido a la alta mortalidad registrada en las concentraciones experimentales en laboratorio y microcosmos, las cuales fueron 40 y 122 veces menores al valor de aplicación del insecticida (500 mg/L y 1,52 mg/ha, respectivamente). Por otra parte, se encontró una reducción significante en la longitud total y la capacidad de natación de las larvas obtenidas de los embriones expuestos a la CY, pero no en el tiempo de desarrollo. En conclusión, la exposición a la cipermetrina provocó una letalidad alta en los renacuajos y efectos subletales en estadíos tempranos del desarrollo, por lo que a las concentraciones recomendadas de aplicación, este insecticida es tóxico para las especies de estudio.
ABSTRACT The cypermethrin (CY) insecticide is used in agriculture for the control of pests; however, due to its neurological action can affect non-target organisms such as anurans. The aim of this study was to evaluate the toxicity (median lethal concentration: LC50, and some sublethal effects: developmental delays, swimming performance and total length of larvae) of the insecticide CY (Cypermon® 20EC) exposed during 96 hours to embryos and tadpoles of four anuran species under laboratory and microcosm tests. The embryos of Rhinella humboldti were the most sensitive in laboratory conditions (LC50= 6.27 mg/L) and Boana xerophylla in microcosms (LC50= 88.32 mg/ha), whereas Engystomops pustulosus (laboratory: LC50= 1 1.80 mg/L, microcosms: LC50= 1 12.37 mg/ha) was the most resistant species. Rhinella marina showed an intermediate sensitivity. It was not possible to calculate the tadpole LC50 values due to the high mortality recorded in the experimental concentrations, both in laboratory and microcosms, which were 40 and 122 times lower than the value suggested for the application of the insecticide in field (500 mg/L and 1.52 mg/ha, respectively). On the other hand, it was found a significant decreasing in the total length and swimming performance of the larvae obtained from the embryos exposed to CY, but not in the embryonic developmental time. In conclusion, the exposure to the cypermethrin produced a high tadpole lethality and sublethal effects on developing embryos; therefore, under the recommended concentrations of field exposition, this insecticide is toxic for the study species.
ABSTRACT
Abstract Deionized ammonium (NH3) acute toxicity (LC50-96h) in Patagonian blenny juveniles (Eleginops maclovinus) was assessed. Concentrations of deionized ammonium in salt water were prepared by using 24.09 ± 2.1 g ammonium chloride (NH4Cl). Fish were exposed in triplicates to different ammonium concentrations: 0.05; 0.094; 0.175; 0.325 and 0.605 mg NH3 L-1. Additionally, a control group was included. Experimental fish were kept at a photoperiod of 16:8h. Average temperatures were 16.24 ± 1.40 °C. Oxygen concentration was 7.16 ± 0.40 mg L -1. Water pH was 7.89 ± 0.2. LC50-96 h, was estimated by using Probit statistical method (95% intervals) using EPA software (1993). Juveniles of E. maclovinus showed a LC50-96h of 0.413mg NH3 L-1 value, different from most marine species. This study presents the first record of ammonium toxicity in marine species of Chile.
Resumo A toxicidade aguda (LC50-96h) de amônia deionizada (NH3 ) em Babosas-da-Patagônia (Eleginops maclovinus) juvenis foi avaliada. As concentrações de sal de amônia deionizada em água foram preparados com 24,09 ± 2,1 g de cloreto de amônio (NH4Cl). Os peixes foram expostos em triplicata a diferentes concentrações de amônia: 0,05; 0,094; 0,175; 0,325 e 0,605 mg L-1 de NH3. Além disso, um grupo de controle foi incluído. Peixes experimentais foram mantidos em fotoperíodo de 16: 8h. As temperaturas médias foram 16,24 + 1,40 °C. A concentração de oxigênio foi 16.24 +1.40°C mg L-1 . O pH da água foi de 7,89 + 0,2. h LC50-96h, foi estimada usando o método estatístico de Probit (intervalos de 95%) usando o software EPA (1993). E. maclovinus juvenis apresentaram uma LC 50-96h de 0.413mg NH3 L-1 valor diferente da maioria das espécies marinhas. Este estudo apresenta o primeiro registro de toxicidade amónio em espécies marinhas do Chile.
ABSTRACT
O tiametoxam é um inseticida neonicotinóide usado em diversas culturas e classificado como perigoso para o meio ambiente.O objetivo do presente trabalho foi avaliar a toxicidade aguda do inseticida, por meio da determinação da CL50%, e o risco ecotoxicológico com mensuração da concentração ambiental estimada (CAE) e do quociente de risco (QR). O experimento foi realizado com alevinos de tilápias expostas a 150, 300, 450, 600 e 750mg/L de Actara(R) WG por um período total de 96 horas. O oxigênio dissolvido, o pH e a temperatura foram mensurados diariamente em todos os aquários. Nos grupos experimentais, houve uma variação dos valores de pH e de OD para as diferentes concentrações do inseticida. A CL50% 96h do Actara(R) para alevinos de tilápia foi de 322,08ppm. O quociente de risco (QR) variou de baixo a alto, de acordo com a metodologia usada.(AU)
The neonicotinoid insecticide thiamethoxam is used in different cultures and classified as dangerous for the environment. The aim of this study was to evaluate the acute toxicity of thiamethoxam by determining the lethal concentration (LC50) and ecotoxicological risk through Estimated Environmental Concentration (EEC) and Risk Quotient (RQ) measurement. The assays were done with Tilapia fingerlings exposed to 150, 300, 450, 600 and 750mg / L Actara WG during 96 hours. Dissolved oxygen, pH and temperature were measured daily in all aquariums. Dissolved oxygen and pH varied in the experimental groups. The LC50 Actara(R); 96h was 322.08ppm. The risk quotient (RQ) ranged from low to high according to the methodology used.(AU)
Subject(s)
Animals , Toxicity Tests, Acute , Cichlids , Environmental Pollution/analysis , Insecticides/toxicity , Lethal Dose 50ABSTRACT
The aim of this research was to evaluate the feasibility for the use of the organisms Lemna minor, Azolla caroliniana, Hyphessobrycon eques, Pomacea canaliculata and Daphnia magna as exposure bioindicators for ethanol (lethal and effective concentration 50% - LC50(I)/EC50(I)). Thus, the following concentrations were used 5.0; 10.0; 20.0; 30.0; 40.0 and 50.0 mg L-1 ethanol on L. minor; 25.0; 50.0; 75.0; 100.0; 150.0 and 200.0 mg L-1 on A. caroliniana; 0.3; 0.5; 1.0; 2.0 and 3.0 mg L-1 on H. eques; 0.05; 0.10; 0.20; 0.40 and 0.80 mg L-1 on P. canaliculata; and 40.0; 60.0; 80.0; 100.0; 120.0 and 140.0 mg L-1 on D. magna. An untreated control was also kept for all organisms, with three repetitions. The increase in the ethanol concentration elevated the electrical conductivity and decreased the water dissolved oxygen and pH. The ethanol LC50 for L. minor and A. caroliniana were 12.78 and 73.11 mg L-1, respectively, and was classified as slightly toxic; 1.22 mg L-1 for H. eques (moderately toxic); 0.39 mg L-1 for P. canaliculata (highly toxic) and 98.85 mg L-1 for D. magna (slightly toxic). Thus, H. eques and P. canaliculata have showed good potential for the use as ethanol exposure bioindicators on water bodies.
O objetivo deste estudo foi avaliar a viabilidade do uso dos organismos teste Lemna minor, Azolla caroliniana, Hyphessobrycon eques, Pomacea canaliculata e Daphnia magna como bioindicadores de exposição ao etanol (concentração letal e efetiva 50% - CL50(I)/CE50(I)). Assim, foram utilizadas as seguintes concentrações: 5,0; 10,0; 20,0; 30,0; 40,0 e 50,0 mg L-1 de etanol para L. minor; 25,0; 50,0; 75,0; 100,0; 150,0 e 200,0 mg L- 1 (A. caroliniana); 0,3; 0,5; 1,0; 2,0 e 3,0 mg L-1 (H. eques); 0,05; 0,10; 0,20; 0,40 e 0,80 mg L-1 (P. canaliculata ) e 40,0; 60,0; 80,0; 100,0; 120,0 e 140,0 mg L-1 para D. magna, todos com controle em triplicata. O aumento da concentração do etanol elevou a condutividade elétrica e diminuiu o oxigênio dissolvido e o pH da água. A CL50 do etanol para as macrófitas L. minor e A. caroliniana foi 12,78 e 73,11 mg L-1, respectivamente, sendo classificado como ligeiramente tóxico; para o H. eques, foi de 1,22 mg L-1 (moderadamente tóxico); 0,39 mg L-1 para o P. canaliculata (altamente tóxico) e 98,85 mg L-1 para D. magna (ligeiramente tóxico). Assim, o H. eques e o P. canaliculata apresentaram potencial para uso como organismos bioindicadores de exposição do etanol em corpos hídricos.
Subject(s)
Aquatic Organisms , Ecology , Environment , Environmental Biomarkers , EthanolABSTRACT
El Propanil es un herbicida empleado en el control de arvenses que puede afectar organismos no blanco como los anuros. El objetivo del trabajo fue evaluar los efectos letales (concentración letal media, CL50) y subletales (retrasos en el desarrollo, longitud total y máxima distancia de natación) del Propanil (Propanil Trust® 500EC) sobre embriones y renacuajos de tres especies de anuros bajo condiciones de laboratorio y microcosmos, que incluyen algunos componentes de campo (sedimentos y material vegetal). La especie más sensible fue Rhinella humboldti (embriones: laboratorio CL50= 9,14 mg/L y microcosmos CL50= 83,92 mg/ha; renacuajos: laboratorio CL50= 5,09 mg/L y microcosmos CL50= 44,52 mg/ha), y la más resistente Hypsiboas crepitans (embriones: laboratorio CL50= 19,58 mg/L y microcosmos CL50= 179,53 mg/ha; renacuajos: laboratorio CL50= 16,54 mg/L y microcosmos CL50= 190,72 mg/ha). Engystomops pustulosus mostró una sensibilidad intermedia. En general, en laboratorio los CL50 indicaron una letalidad alta y se encontraron cambios significantes en la longitud total y la máxima distancia de natación de los organismos expuestos al Propanil, contrario a los resultados en microcosmos, aunque el tiempo de desarrollo embrionario no mostró diferencias entre tratamientos. Al comparar los CL50 se encontró que los renacuajos fueron más sensibles al herbicida que los embriones. En conclusión, el Propanil resultó tóxico para los embriones y renacuajos en condiciones de laboratorio pero tuvo un efecto menor en microcosmos. Esto demuestra que los componentes de campo de los microcosmos y la falta de renovación de las soluciones reducen la toxicidad del Propanil en los anuros de estudio.
Propanil is an herbicide used to control weeds that can affect non-target organisms such as anurans. The aim of this study was to assess the lethal (median lethal concentration, LC50) and sublethal effects (delays in development, total length and maximum swimming distance) of Propanil (Propanil Trust® 500EC) on embryos and tadpoles of three species of anurans under laboratory and microcosm conditions, which include some field components (sediments and vegetal materials). The most sensitive species was Rhinella humboldti (embryos: laboratory LC50= 9.14 mg/L and microcosm LC50= 83.92 mg/ha; tadpoles: laboratory LC50= 5.09 mg/L and microcosm LC50= 44.52 mg/ha), whereas the most resistant was Hypsiboas crepitans (embryos: laboratory LC50= 19.58 mg/L and microcosm LC50= 179.53 mg/ha; tadpoles: laboratory LC50= 16.54 mg/L and microcosm LC50= 190.72 mg/ha). Engystomops pustulosus showed an intermediate sensitivity. In general, in laboratory the LC50 indicated a high lethality and were found significant changes in the total length and maximum swimming distance of the organisms exposed to Propanil, as opposed to the microcosm results, although the time of embryonic development did not show differences between treatments. Comparing the LC50, it was established that tadpoles were more sensitive to the herbicide than embryos. In conclusion, the Propanil was toxic to embryos and tadpoles in laboratory tests but had a low effect in microcosms. This demonstrates that the field components of the microcosms and the lack of solution renewals notably decrease the toxicity of Propanil on the anurans studied.
ABSTRACT
ABSTRACT: The aim of this study was to evaluate the bioactivity of microencapsulated extract from the soursop seeds, Annona muricata L. (Annonaceae), on diamondback moth, Plutella xylostela L. (Lepidoptera: Plutellidae). Microencapsulation was performed in a Mini Spray Dryer model B-290 using 50mL of ethanolic and hexanic extracts plus 150mL of ethanol and 150mL of ultrapure water, mixed with aerosil (first polymer) or arabic gum (second polymer). It was possible to microencapsulate the ethanolic extract of soursop seeds only by using the polymer arabic gum at 20%. The microencapsulated extract caused significant acute toxicity (LC50=258mg L-1) and chronic effects, especially reduction of larval viability and increased larval stage. We concluded that the microencapsulation of the ethanolic extract of soursop seeds can be a viable alternative for controlling diamondback moth with possible gains for the environment.
RESUMO: O objetivo deste estudo foi avaliar a bioatividade do extrato microencapsulado das sementes de graviola, Annona muricata L. (Annonaceae), sobre a traça-das-crucíferas, Plutella xylostella L. (Lepidoptera: Plutellidae). A microencapsulação foi realizada em um Mini Spray Dryer modelo B-290 utilizando-se 50mL dos extratos etanólico e hexânico mais 150mL de álcool etílico e 150mL de água ultrapurificada, misturado com aerosil (primeiro polímero) ou com goma arábica (segundo polímero). Só foi possível microencapsular o extrato etanólico de sementes de graviola com a utilização do polímero goma arábica a 20%. O extrato microencapsulado causou significativa toxicidade aguda (CL50=258mg L-1) e efeitos crônicos, especialmente redução da viabilidade larval e aumento da duração do estágio larval. Conclui-se que a microencapsulação do extrato etanólico da semente de graviola pode ser uma alternativa viável no controle da traça com possíveis ganhos para o meio ambiente.
ABSTRACT
Objective To study the acute inhalation toxicity of 50% Luowei,a plant molluscacide,in rats. Methods Twenty adult Wistar rats,half male and half female,were given of 5000 mg/m3 of 50% Luowei through a dynamic inhalation de?vice and the death and recovery of the rats were observed within 14 days,and LC50 was drawn. Results After exposure,the ac?tivities of the rats decreased and a few individual animals had scratching symptom,but the symptom disappeared after the expo?sure. No animals died during the whole observation period. Therefore,the acute inhalation LC50 was greater than 5000 mg/m3 for rats,and Luowei belonged to low toxicity level. Conclusions 50% Luowei will not cause animal death if it is inhaled into ani?mal body. However,people still need to wear protective equipment in production and use.
ABSTRACT
Objective To determine whether or not capsazepine(CPZ),a transient receptor po-tential vanilloid-1(TRPV1)antagonist,attenuates lidocaine-induced cytotoxicity on rat dorsal root ganglion (DRG)neurons in vitro.Methods Adequate DRG neurons from 3-day neonatal Wistar rats were obtained,cultured and purified in vitro.To achieve higher cell viability,we reduced the concen-tration of trypsin to 0.125% compared with others.The purified DRG neurons were incubated with 0,2.5,5,10,20 and 40 mmol/L lidocaine for 10 min,respectively,their viabilities were examined using Cell Counting Kit(CCK-8)assay,and the lethal concentration 50(LC50 )of lidocaine on DRG neurons was calculated.Then,the variation of lidocaine-induced cell viability at LC50 ,when 0,1,10 and 100 μmol/L CPZ were respectively added to the incubations,was examined with CCK-8 assay. Results The purified percentage of DRG neurons was as high as 91% after digesting by 0.125%trypsin and purifying in vitro.Cell viability of DRG neurons in group L1,L2,L3,L4,L5 was signifi-cantly down regulated compared with the control group,to be specific,that of L3,L4,L5 being re-markably lower than that of L1,that of L4,L5 lower than that of L2 and that of L5 lower than that L3 and L4.After lidocaine induced DRG neurons for 10 min,LC50 was 30 mmol/L;10 μmol/L and 100 μmol/L CPZ significantly reduced LC50 DRG neuron toxicity induced by lidocaine (P <0.05). The effect of 10 μmol/L CPZ had reached the maximal effect,decreasing the cell viability decrease from 50% to 35%.Conclusion The novel method in this experiment is effective to obtain good DRG neurons,the LC50 of lidocaine on rat DRG neurons is 30 mmol/L,and CPZ attenuates the cytotoxicity induced by lidocaine on rat DRG neurons.
ABSTRACT
El Roundup® Activo es un herbicida elaborado a base de glifosato ampliamente utilizado en Colombia para el control de malezas. Sin embargo, para su aplicación requiere ser mezclado con un coadyuvante que facilite su acción, tal como el Cosmo-Flux®411F el cual mejora la adherencia y fijación del herbicida en las hojas de las plantas. El objetivo de este estudio fue determinar la concentración letal media (CL50) y algunos efectos subletales (cambios en el tamaño corporal y en el desempeño natatorio) del Roundup® Activo y del Cosmo-Flux®411F en renacuajos de cuatro especies de anuros colombianos expuestos bajo condiciones controladas de laboratorio y en microcosmos. La especie más sensible a la exposición del Roundup® Activo fue Hypsiboas crepitans (Laboratorio: CL50 = 1414 µg a.e. de glifosato/L y microcosmos: CL50= 4 kg a.e. de glifosato/ha) y para el Cosmo-Flux®411F Rhinella humboldti (Laboratorio: CL50= 319 mg/L y microcosmos: CL50 = 632,3 L/ha). En laboratorio y microcosmos, la exposición al Roundup® Activo no alteró el tamaño corporal ni el desempeño natatorio de los renacuajos, mientras que el Cosmo-Flux®411F generó alteraciones del tamaño corporal pero no afectó el desempeño natatorio. Al comparar los CL50 de los dos agroquímicos con las concentraciones empleadas en campo, el Roundup® Activo generó un riesgo moderado mientras que el Cosmo-Flux®411F no resultó letal. Además, el Roundup® Activo fue notablemente más tóxico que el Cosmo-Flux®411F.
Roundup® Active is an herbicide based on glyphosate widely used in Colombia for control of illicit crops and weeds. However, it must be mixed with an adjuvant that facilitates its action, such as the Cosmo-Flux®411F which improves the adhesion and fixation of the herbicide into the leaves of the plants. The aim of this study was to determine the median lethal concentration (LC50) and some sublethal effects (changes in body size and swimming performance) of the Roundup® Active and the Cosmo-Flux®411F to tadpoles of four Colombian anuran species exposed under laboratory and microcosm conditions. The most sensitive species to exposure of Roundup® Active was Hypsiboas crepitans (Laboratory: LC50= 1414 µg a.e. glyphosate/L; microcosm: LC50= 4 kg a.e. glyphosate/ha), and for Cosmo-Flux®411F was Rhinella humboldti (Laboratory: LC50= 319 mg/L; microcosm: LC50= 632.3 L/ha). In laboratory and microcosms, Roundup® Active did not alter the tadpole body size nor the swimming performance, while the Cosmo-Flux®411F generated changes in the body size but not in the swimming performance. Comparing the LC50 of the two agrochemicals with respect to concentrations used in field, the Roundup® Active exerted a moderate risk whereas the Cosmo-Flux®411F was not lethal. In addition, the Roundup® Active was notably more toxic than the Cosmo-Flux®411F.
ABSTRACT
The aim of this study was to determine the lethal salinity (LC50) for the yellow clam Mesodesma mactroides (Bivalvia: Mesodesmatidae) and identify histopathological alterations that could be used to diagnose structural changes in clam tissue. Clams in two size classes (adults and juveniles) were placed in 10 L chambers and exposed to salinities of 35, 30, 25, 20, 15, 10, and 5 g/L. There were triplicate chambers with seven clams each for each salinity. The LC50 values for a 48 h exposure were 6.5 g/L and 5.7 g/L for adults and juveniles, respectively. For a 96 h exposure, the LC50 values were 10.5 g/L for adults and 8.8 g/L for juveniles. The histological examination of yellow clams exposed to 10 g/L for 96 h showed intercellular oedema and necrotic foci in the epithelium of the digestive gland and occlusion of the lumen of the digestive gland. In conclusion, M. mactroides can be characterised as a moderately euryhaline species, tolerating salinities from 35 to 15 g/L.
O objetivo deste estudo foi determinar a salinidade letal (CL50) para o marisco branco Mesodesma mactroides (Bivalvia: Mesodesmatidae) e as alterações histopatológicas que poderiam ser úteis para o diagnóstico de mudanças estruturais no tecido dos bivalves. Mariscos de duas classes etárias de tamanha (juvenis e adultos) foram colocados em recipientes de 10 L e expostos a salinidades de 35, 30, 25, 20, 15, 10 e 5 g/L. Os tratamentos foram realizados em triplicata com sete bivalves em cada recipiente, A CL50 para 48 h de exposição foi 6,5 g/L e 5,7 g/L para adultos e juvenis, respectivamente. Para 96 h de exposição, a CL50 foi 10,5 g/L para adultos e 8,8 g/L para juvenis. O exame histológico dos mariscos expostos à salinidade de 10 g/L por 96 h revelou edema intracelular e focos necróticos no epitélio da glândula digestiva e oclusão da luz da glândula digestiva. Em conclusão, M. mactroides pode ser considera uma espécie eurialina moderada, tolerando salinidades de 35 até 15 g/L. .