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Used Pesticides (used + pesticide)
Selected AbstractsComparing the impact of conventional pesticide and use of a transgenic pest-resistant crop on the beneficial carabid beetle Pterostichus melanariusPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 10 2006Evan A Mulligan Abstract The potential impact of a chemical pesticide control method has been compared with that of transgenic plants expressing a protease inhibitor conferring insect resistance by utilising a tritrophic system comprising the crop plant Brassica napus (L.) (Oilseed rape), the pest mollusc Deroceras reticulatum (Müller) and the predatory carabid beetle Pterostichus melanarius (Illiger). Cypermethrin, as the most widely used pesticide in UK oilseed rape (OSR) cultivation, was selected as the conventional treatment. OSR expressing a cysteine protease inhibitor, oryzacystatin-1 (OC-1), was the transgenic comparator. In feeding trials, D. reticulatum showed no significant long-term effects on measured life history parameters (survival, weight gain, food consumption) as a result of exposure to either the cypermethrin or OC-1 treatment. However, D. reticulatum was able to respond to the presence of the dietary inhibitor by producing two novel proteases following exposure to OC-1-expressing OSR. Similarly, P. melanarius showed no detectable alterations in mortality, weight gain or food consumption when feeding on D. reticulatum previously fed either pesticide-contaminated or GM plant material. Furthermore, as with the slug, a novel form of protease, approximately Mr 27 kDa, was induced in the carabid in response to feeding on slugs fed OC-1-expressing OSR. Copyright © 2006 Society of Chemical Industry [source] A physiologically based pharmacokinetic model for endosulfan in the male Sprague-Dawley ratsENVIRONMENTAL TOXICOLOGY, Issue 5 2006Melissa P. L. Chan Abstract Endosulfan, an organochlorine (OC) insecticide belonging to the cyclodiene group, is one of the most commonly used pesticides to control pests in vegetables, cotton, and fruits. To date, no physiologically based pharmacokinetic (PBPK) model has been located for endosulfan in animal species and humans. The estimation by a mathematical model is essential since information on humans can scarcely be obtained experimentally. The PBPK model was constructed based on the pharmacokinetic data of our experiment following single oral administration of 14C-Endosulfan to male Sprague-Dawley rats. The model was parameterized by using reference physiological parameter values and partition coefficients that were determined in the experiment and optimized by manual adjustment until the best visual fit of the simulations with the experimental data were observed. The model was verified by simulating the disposition of 14C-Endosulfan in vivo after single and multiple oral dosages and comparing simulated results with experimental results. The model was further verified by using experimental data retrieved from the literature. The present model could reasonably predict target tissue dosimetries in rats. Simulation with three-time repeated administration of 14C-Endosulfan and experimental data retrieved from the literature by the constructed model fitted fairly well with the experimental results; thus suggesting that the newly developed PBPK model was developed. Sensitivity analyses were used to determine those input parameters with the greatest influence on endosulfan tissue concentrations. © 2006 Wiley Periodicals, Inc. Environ Toxicol 21: 464,478, 2006. [source] Development of an in vitro blood,brain barrier model to study the effects of endosulfan on the permeability of tight junctions and a comparative study of the cytotoxic effects of endosulfan on rat and human glial and neuronal cell culturesENVIRONMENTAL TOXICOLOGY, Issue 3 2006Melissa P. L. Chan Abstract Endosulfan, an organochlorine (OC) insecticide that belongs to the cyclodiene group, is one of the most commonly used pesticides to control pests in vegetables, cotton, and fruits. Porcine brain microvascular endothelial cells were used to develop a model to study the effects of endosulfan on the permeability of tight junctions in the blood,brain barrier (BBB). BBB permeability, measured as transendothelial electrical resistance, decreased in a dose- and time-dependent manner when treated with ,-endosulfan, ,-endosulfan, or endosulfan sulfate. Cytotoxicity testing revealed that the three endosulfans did not cause cell death at concentrations of 10 ,M and below. The ratio of the average permeability of the filter-grown endothelial cell monolayer to 14C-endosulfan (Pe) going from the outer to the inner compartments with that going from the inner to the outer compartments was approximately 1:1.2,2.1 after exposure to concentrations of 0.01,10 ,M. ,-Endosulfan, ,-endosulfan, and endosulfan sulfate had cytotoxic effects on rat glial (C6) and neuronal (PC12) cell cultures as well as on human glial (CCF-STTG1) and neuronal (NT2) cell cultures. The effects of ,-endosulfan were highly selective, with a wide range of LC50 values found in the different cultures, ranging from 11.2 ,M for CCF-STTG1 cells to 48.0 ,M for PC12 cells. In contrast, selective neurotoxicity was not so manifest in glial and neuronal cell cultures after exposure to endosulfan sulfate, as LC50 values were in the range of 10.4,21.6 ,M. CCF-STTG1 cells were more sensitive to ,-endosulfan and endosulfan sulfate, whereas NT2 cells were more sensitive to ,-endosulfan. © 2006 Wiley Periodicals, Inc. Environ Toxicol 21: 223,235, 2006. [source] Early signs of lethal effects in Daphnia magna (Branchiopoda, Cladocera) exposed to the insecticide cypermethrin and the fungicide azoxystrobinENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 10 2010Ursula Friberg-Jensen Abstract This study presents the effects of sublethal concentrations of pesticides cypermethrin and azoxystrobin on the activity of several physiological parameters of egg-carrying Daphnia magna studied using a video-image technique. Single tethered daphnids were continuously recorded for 24,h of pesticide exposure, and the activity of the heart, the filtering limbs, the mandibles, and the focal spine were subsequently analyzed. Acute toxicity tests based on the criteria of immobilization were performed on egg-carrying D. magna, and sublethal concentrations of 0.1, 1.0, and 10,µg/L cypermethrin and 0.5, 1.0, and 2.0,mg/L azoxystrobin were established. At a concentration as low as 0.1,µg/L cypermethrin, the 5% effective concentration after 24,h of exposure (EC5,24h), the activity of the focal spine increased and the filtering limb activity decreased. The activity of the mandibles was reduced by exposure to 1.0 (EC18,24,h) and 10,µg/L (EC41,24,h) cypermethrin, whereas heart activity increased at a concentration of 10,µg/L (EC41,24,h). With regard to azoxystrobin, the activity of all response parameters except the focal spine decreased by exposure to 0.5,mg/L (EC4,24h) azoxystrobin. The focal spine was not affected by azoxystrobin. The results show that physiological mechanisms important for ingestion of food in D. magna may be impaired by low concentrations of commonly used pesticides. Environ. Toxicol. Chem. 2010;29:2371,2378. © 2010 SETAC [source] Lindane removal induction by Streptomyces sp.JOURNAL OF BASIC MICROBIOLOGY, Issue 5 2006Gamma-hexachlorocyclohexane (,-HCH or lindane), one of the most commonly used pesticides, has been mainly used in agriculture; this pesticide is known to be highly toxic and persistent, causing serious water and soil contamination. The objective of the present work is to study the effect of low glucose concentration and the addition of lindane at different growing time on the pesticide detoxification ability of Streptomyces M7. After 96 h of incubation in synthetic medium containing glucose 0.6 g l,1 with the addition of lindane 100 ,g l,1 at 20 h of incubation, a typical diauxic curve was obtained: glucose was the preferred substrate until 24 h, at 48 h, when the carbohydrate was depleted, the microorganism consumed the pesticide like carbon source. On the other hand, lindane removal induction was observed, which was greater when the pesticide was added to the medium at 20 h than 6 h of incubation. Between 72 and 96 h, a maximum of ,86% of the Cl, was released when lindane was added to the medium at 20 h, whereas ,70% and 67% Cl, was released in the medium when the pesticide was added at 0 and 6 h of incubation respectively. This is the first report of chloride release from inoculated medium supplemented with lindane, suggesting that the pesticide was degraded by Streptomyces sp. under aerobic conditions. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] A screening tool for vulnerability assessment of pesticide leaching to groundwater for the islands of Hawaii, USAPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 4 2007Fredrik Stenemo Abstract This paper describes an updated version of a screening tool for groundwater vulnerability assessment to evaluate pesticide leaching to groundwater, based on a revised version of the attenuation factor. The tool has been implemented in a geographical information system (GIS) covering the major islands of the state of Hawaii, USA. The Hawaii Department of Agriculture currently uses the tool in their pesticide evaluation process as a first-tier screening tool. The basic soil properties and pesticide properties necessary to compute the index, and estimates of their uncertainty, are included in the GIS. Uncertainties in soil and pesticide properties are accounted for using first-order uncertainty analysis. Classifications of pesticides as ,likely', ,uncertain' or ,unlikely' to leach are made on the basis of the uncertainty and a comparison of the revised attenuation factor with values and uncertainties of two reference chemicals. The reference chemicals represent what are considered to be a ,leachable' and a ,non-leachable' pesticide under Hawaii conditions. It is concluded that the tool is suitable for screening new and already used pesticides for the islands of Hawaii. However, the tool is associated with uncertainties that are not accounted for, so a conservative approach with respect to interpretation of the results and selection of pesticide parameters used in the tool is recommended. Copyright © 2007 Society of Chemical Industry [source] Variation across the agricultural season in organophosphorus pesticide urinary metabolite levels for Latino farmworkers in eastern North Carolina: Project design and descriptive resultsAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 7 2009Thomas A. Arcury PhD Abstract Background Community Participatory Approach to Measuring Farmworker Pesticide Exposure, PACE3, used a longitudinal design to document pesticide biomarkers among farmworkers. This article presents an overview of PACE3 and provides a descriptive analysis of participant characteristics and one set of pesticide biomarkers, the dialkylphosphate (DAP) urinary metabolites of organophosphorus (OP) pesticides. Methods Two hundred eighty seven farmworkers were recruited during 2007 from 44 farmworker camps in 11 eastern North Carolina counties. Participants provided interviews, urine samples, blood samples, and saliva samples up to four times at monthly intervals beginning in May. A total of 939 data points were collected. Results Farmworkers were largely men (91.3%) from Mexico (94.8%) with a mean age of 33.7 years (SE 0.82); 23.3% spoke an indigenous language. Across all data points, frequencies of detection and median urinary concentrations were 41.3% and 0.96,µg/L for dimethylphosphate (DMP), 78.3% and 3.61,µg/L for dimethylthiophosphate (DMTP), 33.3% and 0.04,µg/L for dimethyldithiophosphate (DMDTP), 40.5% and 0.87,µg/L for diethylphosphate (DEP), 32.3% and 0.17,µg/L for diethylthiophosphate (DETP), and 8.09% and 0.00,µg/L for diethyldithiophosphate (DEDTP). The frequencies of detection and urinary concentrations of the DAP metabolites increased during the season. Conclusions More PACE3 participants were from Mexico, male, migrant workers, and spoke an indigenous language compared to national data. PACE3 participants had comparable frequencies of detection and urinary metabolite concentrations with participants in other studies. Variability in the frequencies of detection and urinary concentrations of the DAP metabolites indicates the importance of longitudinal studies of biomarkers of currently used pesticides in farmworker populations. Am. J. Ind. Med. 52:539,550, 2009. © 2009 Wiley-Liss, Inc. [source] | ||||||||||