Toxicity induced by dieldrin and chlorpyrifos in the freshwater crayfish Cambarellus montezumae (Cambaridae) / Toxicidad inducida por dieldrín y clorpirifós en Cambarellus montezumae (Cambaridae)

The toxicity induced by insecticides in aquatic organisms is of utmost relevance because it may give a clue about the degree of health or damage of the involved ecosystem. In the present report, we determined the effect of dieldrin (DD) and chlorpyrifos (CP) on the freshwater crayfish, Cambarellus montezumae. The organisms (4-6cm in diameter) were collected in the Ignacio Ramírez Reservoir, situated at 50km Northeast of Mexico City, in the Rio Lerma Basin. Initially, we determined the LC50 value with the Probit method, then the DNA damage with single cell gel electrophoresis (comet assay applied at 24, 48, and 72h of exposure) to the brain and hepatopancreas of animals exposed (in reconstituted water) to 0.05 and 0.5µg/L of each insecticide. In the hepatopancreas of the same organisms, we determined the lipid peroxidation by applying the TBARS test. DNA damage and lipid peroxidation were also evaluated with the same methods to organisms exposed in water from the reservoir. In regard to the LC50 at 72h of exposure, we found a value of 5.1µg/L and a value of 5.62µg/L for DD and CP, respectively. The comet assay applied at different exposure times showed significant DNA damage to both organs, with respect to the control level. In the case of DD, statistical significance was observed for the two doses in the whole evaluated schedule. CP was genotoxic in the brain with the high dose at 72h, and in the hepatopancreas with the two tested doses at all evaluated exposure times. Also, a significant lipid peroxidation increase was detected with the two doses of insecticides. In the study with water from the reservoir, a more pronounced DNA damage was detected. Our results showed strong DNA damage induced by both insecticides in the crayfish, as well as a correlation with the lipid peroxidation effect, suggesting that oxidative stress is involved in the genotoxic alteration. Our results also showed the usefulness of the studied organism as well as the applied tests for the evaluation of toxicological effects, and suggested the pertinence of applying the comet assay to other freshwater organisms to evaluate the bioaccumulation of insecticides. Rev. Biol. Trop. 63 (1): 83-96. Epub 2015 March 01.

La toxicidad inducida por insecticidas en organismos acuáticos es de gran relevancia porque puede orientar sobre el grado de salud o daño del ecosistema involucrado. En el presente estudio determinamos el efecto del dieldrín (DD) y del clorpirifós (CP) en el acocil de agua dulce Cambarellus montezumae. Los organismos (4-6cm de diámetro) se recolectaron en la Represa Ignacio Ramírez, situada a 50km al Noreste de la Ciudad de México, en la cuenca del Río Lerma. Inicialmente determinamos la LC50 con el método de Probit y después el daño al ADN mediante la electroforesis unicelular en gel (ensayo cometa, aplicado a las 24, 48 y 72 h de exposición) en el cerebro y el hepatopáncreas de animales expuestos (en agua reconstituida) a 0.05 y 0.5µg/L de cada insecticida. En el hepatopáncreas de los mismos organismos determinamos la peroxidación lipídica aplicando la prueba de TBARS. El daño al ADN y la peroxidación lipídica también se evaluaron con los mismos métodos en organismos expuestos a los insecticidas en agua de la represa. En relación a la LC50, a las 72h de exposición encontramos un valor de 5.1µg/L y un valor de 5.62µg/L para DD y CP, respectivamente. El ensayo cometa aplicado a diferentes tiempos de exposición mostró un significativo daño al ADN en ambos órganos con respecto al valor del testigo. En el caso del DD se observó significancia estadística para las dos dosis en todo el horario evaluado. CP fue genotóxico en el cerebro con la dosis más alta a las 72 h y en hepatopáncreas con las dos dosis, en todos los tiempos de exposición evaluados. También se detectó un significativo aumento de la peroxidación lipídica con las dos dosis de los insecticidas. En el estudio con el agua de la represa se detectó un daño más pronunciado en el ADN. Nuestros resultados mostraron un fuerte daño al ADN en Cambarellus montezumae por ambos insecticidas, así como una correlación con el efecto de la peroxidación lipídica, lo que sugiere que el estrés oxidativo está involucrado en la alteración genotóxica. Nuestros resultados también mostraron la utilidad del organismo estudiado y de las pruebas aplicadas para evaluar efectos tóxicos, y sugieren la pertinencia de aplicar el ensayo cometa en otros organismos de agua dulce para evaluar la bioacumulación de insecticidas.

Effects of early postnatal exposure to dieldrin on synaptic development of striatum in mice / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the effects of early postnatal exposure to dieldrin on striatum synaptic development in lactation, adolescence and adulthood of mice.</p><p><b>METHODS</b>The pups were divided into 5 groups randomly. Three groups were exposed to dieldrin (0.01% DMSO solution) at doses of 0.2, 2.0 and 20.0 microg/kg and two control groups were exposed to DMSO or saline by intraperitoneal injection of every other day from postnatal days (PND) 3 to PND13. The striatum were isolated from brain in lactation (PND14), adolescence (PND36) and adulthood (PND98). Western blot assay was used to detect the expression levels of striatal synaptic proteins.</p><p><b>RESULTS</b>The postnatal exposure to dieldrin could reduce the level of growth associated protein (GAP43) of striatum in lactation in a dose-dependent manner. In adolescence, the level of glial fibrillary acidic protein (GFAP) in striatum increased and the levels of tyrosine hydroxylase (TH), GAP43 and post-synaptic density protein 95 (PSD95) decreased with exposure doses. The level of Synapsin I decreased in adolescence male mice. The changes of expression levels of GFAP, TH and PSD95 proteins lasted to adulthood.</p><p><b>CONCLUSION</b>Early postnatal exposure to dieldrin could affect the expression level of GAP43 protein in striatum. The expression levels of TH and PSD95 proteins in striatum decreased in adolescence and adulthood. These results indicated that the early postnatal exposure to dieldrin may persistently interfere in the striatal synaptic development.</p>

Irritability of malaria vector, Anopheles sacharovi to different insecticides in a malaria-prone area

OBJECTIVE@#To determine the susceptibility and irritability level of malaria vector Anopheles sacharovi (An. sachrovi) to different insecticides in a malaria-prone area.@*METHODS@#Susceptibility and irritability levels of field collected strain of An. sacharovi to WHO standard papers of DDT 4%, dieldrin 0.4%, malathion 5%, fenitrothion 1%, permethrin 0.75%, and deltamethrin 0.05% were determined in East Azerbaijan of Iran during reemerging of malaria as described by WHO.@*RESULTS@#Results showed that at the diagnostic dose of insecticides this species exhibited resistance to DDT, tolerant to dieldrin and but somehow susceptible to fenitrothion, malathion, permethrin and deltamethrin. The results of irritability of this species to DDT, lambdacyhalothrin, permethrin cyfluthrin and deltamethrin revealed that DDT had had the most and deltamethrin the least irritancy effect. The average number of take offs/fly/minutes for DDT was 0.8±0.2. The order of irritability for permethrin, lambdacyhalothrin, cyfluthrin and deltamethrin were 0.7±0.2, 0.5±0.2, 0.5±0.3, and 0.2±0.1, respectively.@*CONCLUSIONS@#Results of this study reveals the responsiveness of the main malaria vector to different insecticides. This phenomenon is depending on several factors such as type and background of insecticide used previously, insecticide properties, and physiology of the species. Careful monitoring of insecticide resistance and irritability level of species could provide a clue for appropriate selection of insecticide for malaria control.

Comparative performance of imagicides on Anopheles stephensi, main malaria vector in a malarious area, southern Iran.

BACKGROUND & OBJECTIVES: Jiroft district has subtropical climate and prone to seasonal malaria transmission with annual parasite index (API) 4.2 per 1000 in 2006. Anopheles stephensi Liston is a dominant malaria vector. The monitoring of insecticide susceptibility and irritability was conducted using discriminative dose as described by WHO. METHODS: The IV instar larvae were collected from different larval breeding places and transported to the temporary insectary, fed with Bemax and then 2-3 days-old emerged and sugar-fed adults were used for susceptibility and irritability tests employing WHO methods and kits to organochlorine (OC) and pyrethroid (PY) insecticides. RESULTS: Mortality rates of field strain of An. stephensi were 91.3 +/- 0.14 and 90 +/- 0.47% to DDT and dieldrin, respectively at one hour exposure time but was susceptible to all pyrethroids tested. The average number of take-offs per min per adult was 2.09 +/- 0.13 for DDT, 0.581 +/- 0.05 for dieldrin, 1.85 +/- 0.08 for permethrin, 1.87 +/- 0.21 for lambda-cyhalothrin, 1.53 +/- 0.13 for cyfluthrin, and 1.23 +/- 0.1 for deltamethrin. INTERPRETATION & CONCLUSION: Currently, deltamethrin is being used for indoor residual spraying against malaria vectors in the endemic areas of Iran. The findings revealed that the main malaria species is susceptible to all pyrethroids including deltamethrin, permethrin, cyfluthrin and lambda-cyhalothrin but was tolerant to DDT and dieldrin. This report and the finding are coincided with results of previous studies carried out during 1957-61 in the same area. Irritability tests to OC and PY insecticides revealed the moderate level of irritability to DDT compared to pyrethroids and dieldrin. Monitoring for possible cross-resistance between OC and PY insecticides should come into consideration for malaria control programme.

Endocrine Disruptors

For the previous century, the humans have created an unintended and unwanted problem of endocrine disruptors as a potential threat to our public health. By the name of industrialization, endocrine disruptors are smuggling in the everyday life of people today. Although there are much debate on the reality of their emerging health threat, it is no doubt that there are certain classes of compounds that have the potential to affect hormonal status adversely, leading to abnormal development, reproductive dysfunction, and some cancers. The classes of endocrine disruptors are extensively diverse and even more increasing, such as, polychlorinated biphenyls (PCBs), dioxins, dieldrin, bisphenol A and toxaphene. Although these endocrine disruptors have been prohibited or tightly regulated, many of them are still unrecognized and still used without knowing their potential threat to the biological world. Once they are released into the environment, they usually persist without degradation and even undergo bioaccumulation and bioconcentration in food chain. Comparing with the great concern over the public health, we do not have enough information for these issues. It is now clear that we need further extensive studies for the risk assessment and the protection of human and ecological health from the potential hazards of endocrine disruptors. This article introduces a breif overview of the current status of our knowledge and research on endocrine disruptors.

Exposición perinatal a compuestos orgánicos persistentes: efectos diferidos / Perinatal exposure to persistent organic compounds: delayed effects

Se describen los efectos diferidos de la exposición prenatal a algunos compuestos orgánicos persistentes, por el mecanismo del imprinting (reprogramación celular). Entre estos compuestos están algunas dioxinas, policlorobifenilos, el DDT y su metabolico DDE, el metoxiclor, clordecona (kepone), dieldrina, lindano, benzo(a)pireno y pentaclorofenol. El mecanismo involucra alteraciones irreversibles en la diferenciación o en la programación de diversos tipos celulares, con cambios en las características de algunos de sus receptores hormonales, los que favorecen el desarrollo de diversas patologías más tarde en la vida. Entre los efectos que se detectan durante la edad adulta en animales o humanos expuestos perinatalmente, se destacan alteraciones neuroconductuales, retraso en el desarrollo cognitivo, depresión inmune, infertilidad y otras alteraciones del aparato reproductor masculino y femenino, cambios en concentraciones de receptores para diversas hormonas y neurotransmisores y cambios en la capacidad del hígado a inducir diversos sistemas enzimáticos.

Monitoramento de resíduos de pesticidas organoclorados em amostras ambientais e água potável na região de Bauru / Monitoring of organochlorine pesticides residues in environmental samples and drinking water in Bauru Region (SP)

Este trabalho apresenta um monitoramento de resíduos de pesticidas organoclorados em amostras de água e solo na região de Bauru, no período de 1997 a 2002, podendo, o mesmo protocolo, ser aplicado a outras regiões. As amostras estudadas foram coletadas em áreas agrícolas, buscando-se eleger micro-regiões com culturas representativas da área estudada, com situação geográfica e geoquímica típicas. Os resultados obtidos apontam para uma diminuição da concentração dos compostos alvos, quando avaliados após a estação de tratamento de águas, o que se deve especialmente a capacidade de adsorção dos mesmos na superfície de partículas em suspensão e/ou adsorção na argila utilizada, no sistema de filtro, durante o processo de tratamento da água distribuída a população

Insecticide susceptibility status of Aedes aegypti to DDT and dieldrin in desert and non-desert parts of Rajasthan.

Seasonal prevalence and insecticide susceptibility tests were carried out on the adults of Aedes aegypti, the vector of dengue and dengue hemorrhagic fever(DF/DHF), in three desert (Bikaner, Jaisalmer and Jodhpur) and three non-desert (Alwar, Ajmer and Jaipur) districts of Rajasthan. Among the three species viz. Ae. aegypti, Ae. vittatus and Ae. w-albus encountered during the survey the former was the most prevalent species. Studies were carried out both in rural and urban areas against different concentrations of two organochlorines (DDT and Dieldrin). In rural areas resistance has been observed with DDT and dieldrin both in desert and non-desert parts while an intermediate resistance has been observed in the urban areas with both the insecticides which required further verification. Resistance was more pronounced in rural areas as compared to urban areas. LC50 along with regression equation and Chi-square values have been determined for both the insecticides.

Dieldrin initiates apoptosis in rat thymocytes.

In vitro incubation for 6 hr to pesticide dieldrin resulted in a dose-dependent decrease of cell viability comparable to that of dexamethasone. In vivo experiments also demonstrated that dieldrin administration induced a dose-dependent thymic atrophy which appeared to be mediated by endogenous corticosteroids. Agarose gel electrophorosis analysis, revealed the generation of typical apoptotic oligosomal DNA fragmentation in presence of dieldrin. However, in response to high concentrations of pesticide, cells seemed to undergo necrosis pathway. Thus, it may be concluded that dieldrin induced apoptosis in rat thymocytes.

Mecanismos de acción de xenobióticos en ovocitos de anfibios / Xenobiotic mechanisms of action in amphibian oocytes

Comprender los procesos que determinan la toxicidad de diversas sustancias a nivel celular constituye un desafío para el desarrollo tecnológico actual. Los ovocitos de diversas especies son utilizados con distintos propósitos en investigación. El tamaño de los ovocitos de anfibios y la facilidad con que puede obtenerse un gran número de ellos como células aisladas, hacen de los mismos el sistema de elección para múltiples propósitos, tales como: estudios de las etapas tempranas de la reproducción, técnicas de fertilización in vitro, expresión y caracterización de receptores de membranas plasmática, mecanismos de acción de agonistas, vías metabólicas, etc. El objetivo del presente trabajo con ovocitos de sapo Bufo arenarum es estudiar los mecanismos de acción de sustancias xenobióticas a nivel bioquímico y molecular, en relación con la capacidad de éstas gametas de ser fertilizadas y avanzar a través de los estadios tempranos del desarrollo embrionario. Se ha trabajado con diversos biomarcadores que permitieron reconocer los mecanismos de toxicidad de compuestos organoclorados y más recientemente de algunos metales pesados. Se demostró que la activación de una fosfolipasa C específica por el Dieldrin provoca depleción de mediadores lipídicos y como consecuencia inhibición de la fertilización (desarrollo hasta 4-8 células). Actualmente se estudian los efectos del Zn sobre la fertilización y su probable relación con alteraciones en la actividad de enzimas de la vía de las pentosas, directamente ligada a los mecanismos de detoxificación en presencia de stress oxidativo. El estudio de los mecanismos de citotoxicidad de diversas sustancias resulta de gran utilidad cuando se lleva a cabo en gametas, porque permite también evaluar los efectos de dichas sustancias sobre la reproducción de la especie. Los ovocitos de anfibios son además células de gran interés, por su utilidad en el estudio de la citotoxicidad de una amplia variedad de contaminantes hídricos

Risk Assessment on Carcinogenic Pesticides of Vegetables in Korea / 예방의학회지

OBJECTIVES: The study was conducted to estimate the carcinogenic risks from the ingestion of some carcinogenic pesticides (CPs) in vegetables sampled at a local agricultural product market in Seoul. METHODS: After applying a hazard identification step, we selected four pesticides, such as DDT, dieldrin, folpet, and heptachlor epoxide, for this risk assessment. Concentrations of each pesticide were measured from randomly sampled vegetables. In order to estimate the human exposure levels, we combined the concentration of pesticides in the vegetables with consumption rate of those vegetables. Three scenarios were hypothesized for human exposure assessment. Scenario I was the most conservative which supposed the undetected CPs would be the detection limit values. Scenario II was assumed that the undetected CPs would be a half of the detection limit values, and finally scenario III merely considered only values greater than the detection limit values. We finally presented the estimated carcinogenic risks on the basis of the traditional risk assessment procedure suggested by U.S. EPA. RESULTS: Pesticides including DDT, dieldrin, folpet and heptachlor epoxide were detected in 9 samples (6%) in the range of 0.0006~0.09ppm. The daily intake levels of carcinogenic pesticides were estimated in the range of 0.0009~0.0079 microgram/day. As we expected, excess cancer risks based on scenario I was also the highest (1.1x10-8~ 5.5x10-5). CONCLUSIONS: We found that the estimated risks from the pesticides we investigated were not serious. We, however, propose that a continuos monitoring is needed to make sure for the protection of public health.

El pretratamiento de ovocitos de anfibios con el plaguicida organoclorado Dieldrin, favorece la formación de la membrana de fertilización luego de la inseminación / Pretreatment of amphibian cocytes with the organochlorinated pesticide Dieldrin facilitates the formation of the fertilization membrane after insemination

El plagicida organoclorado Dieldrin inhibe la fertilización de ovocitos de sapo, inseminados "in vitro" luego de 2 horas de incubación en solución de Ringer conteniendo 4 mg/l del pleguicida. La incubación con Dieldrin no conduce por sí misma a los ovocitos a la reacción cortical ni produce alteraciones evidentes en sus membranas vitelinas, pero sí favorece la formación de la membrana de fertilización cuando dichas células son inseminadas con posterioridad al tratamiento. La inhibición de la fertilización de ovocitos de sapo Bufo arenarum-Hensel por el Dieldrin, se produce como consecuencia de efectos del plaguicida sobre eventos posteriores a la reacción cortical, que da lugar a la formación de la membrana de fertilización

Susceptibility status of Phlebotomus argentipes to DDT, dieldrin and malathion in Hoogly, West Bengal.

Susceptibility tests were carried out with DDT (4%), dieldrin (0.4%) and malathion (5%) using the WHO test kits against Phlebotomus argentipes sandflies collected from Dankuni, situated in Hoogly district, 21 km from Calcutta, West Bengal. P. argentipes was found to be susceptible to all the three insecticides tested. LT 50 was calculated to be 10.6 minutes, 10.2 minutes and 2.8 minutes for DDT, dieldrin and malathion against the flies.

Blood chemical changes in rabbits after oral administration of Dieldrin

Twenty four rabbits of same age and body weight were divided into two groups A and B. The treated group A was fed 5mg dieldrin /kg body weight/day. It was observed that maximum dieldrin level reached 84.44 ug/ml. The chemical analysis of blood showed that dieldrin accumulation decreassed blood urea, while creatinine, alkaline phosphatase and acid phosphatase concentrations increased

Laboratory evaluation of five pesticides for control of Leptotrombidium fletcheri (Acari: Trombiculidae).

Five pesticides were evaluated against laboratory colonies of Leptotrombidium fletcheri (Womersly and Heaslip) by the Pasteur pipet technique. The pesticides were dieldrin (LC50 = 3.6 ppm, LC99 = 18.2 ppm), bromopropylate (LC50 = 9.2 ppm, LC99 = 239.6 ppm), dicofol (LC50 = 27.8 ppm, LC99 = 118.1 ppm), fenthion (LC50 = 15.4 ppm, LC99 = 29.7 ppm), and malathion (LC50 = 84.7 ppm, LC99 = 313.9 ppm). Dieldrin was the most toxic. Dicofol was recommended for further evaluation in field trials.

Genetics and mechanism of malathion resistance in anopheles stephensi from Bandar-Abbas and its cross resistance spectrum to DDT, dieldrin and pirmiphos-methyl

The genetics and mechanism of malathion resistance in the adults of An. stephensi [BAN-S], Was studied. Nine successive generations of malathion selection in the adults resulted in an increase in LTSO of about 3-fold. The crossing experiments indicated that the resistance is inherited as partially dominant character with no indication of sex linkage. The results of back-crosses suggested that probably more than one genetic factor are responsible for malathion resistance. Synergist study with TPP and PB indicated that the involvement of carboxyesterase as the main resistance factor in An. Srephensi. The cross- resistance spectrum of malathion resistance with pirimiphos- methyl, DDT and dieldrin were studied in the selected strain. The results did not show any relationship between resistances to malathion, DDTand pirimiphos- methyl. Dieldurin test on the selected and uselected strains showed that malathin resistance could increase dieldrin resitance

Human aldrin poisoning

Sixteen patients acutely poisoned with aldrin were examined to evaluate a possible correlation between serum aldrin and diedrin levels and clinical complaints. The patients were classified as having mild (N = 8), moderate (N = 5) or severe (N = 3) poisoning according to clinical symptoms. Concentrations of less than 20 µg/l were usually associated with mild poisoning, which involved complaints such as nausea, vomiting and epigastric pain, whereas concentrations of 100 to 200 µg/l were considered to represent moderate intoxication and were associated with nausea, vomiting, epigastric pain, headache, dizziness, and convulsions. Sever or fatal cases were associated with levels above 700 µg/l. Taken together,these results suggest that serum aldrin diedrin levels can be used as indicators of clinical prognosis after acute poisoning with these insecticides and that convulsions could suddenly occur even in the absence of prodronal signs or symptoms