Dissertations / Theses on the topic 'Chlorpyrifos'
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Adams, Rachel May. "Transformation of Chlorpyrifos and Chlorpyrifos-Methyl in Prairie Pothole Pore Water." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1429112011.
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Sindi, R. "Chlorpyrifos and chlorpyrifos oxon induce neurite retraction and cytoskeletal disruption in mouse N2a cells and human neural progenitor stem cells." Thesis, Nottingham Trent University, 2015. http://irep.ntu.ac.uk/id/eprint/28045/.
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The widespread use of the organophosphorous insecticide chlorpyrifos (CPF) over recent decades has posed major concerns about its toxicity in humans. Sub-cytotoxic concentrations of CPF and its metabolite CPF-oxon (CPO) were known to inhibit neurite outgrowth in differentiating neural cells but little was known about their ability to cause neurite retraction. The main aims of this study were to investigate the effects of CPF and CPO on the stability of neurites in pre-differentiated mouse N2a neuroblastoma and human ReNcell CX neural stem cells, and to relate toxicity to the regulation of cytoskeletal proteins involved in neural differentiation. At 3 μM, both compounds reduced the numbers of axon-like processes in pre-differentiated N2a cells, as indicated by morphometric analysis of carboxyfluorescein succinimidyl ester-labelled cells. Retraction of neurites was observed within 2 h of exposure by live cell imaging. Neurofilament disruption was detected in treated cells, by indirect immunofluorescence with anti-phosphorylated neurofilament heavy chain (pNFH) monoclonal antibody SMI34, while the microtubule network was unaffected. Western blotting analysis revealed transiently increased levels of reactivity of Ta51 after 2 h exposure but reduced levels of reactivity following 8 h treatment with both compounds, whereas reactivity of anti-total NFH or anti-tubulin were unaffected. Altered NFH phosphorylation at 2 h exposure was associated with increased activation of extracellular signal-regulated protein kinase ERK 1/2. Increased levels of phosphatase activity were observed following 8 h treatment, suggesting that organophosphate-induced neurite retraction in N2a cells is associated with early transient increases in NFH phosphorylation and ERK1/2 activation. High content analysis of immunofluorescently stained N2a cells showed that the induction of neurite retraction by both compounds was concentration-dependent. The same concentrations of CPF and CPO also caused retraction of neurites in differentiating neuronal and glial populations of human ReNcells. Using a cell ELISA technique changes observed in Western blot analysis were confirmed and found to be concentration-dependent in N2a cells. In pre-differentiated ReNcells, reduced levels of NFH phosphorylation were observed, whereas total NFH, βIII-tubulin and ERK1/2 activation were unaffected. Acetylcholinesterase assays suggested that inhibition was not required for neurite retraction but could affect the severity of such effects.
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Harshman, Sean William. "Effects of Chlorpyrifos-oxon on Prohormone Convertase Enzyme Activity." Wright State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=wright1245238369.
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Cattani, Marcus P. S. "Exposures and health effects among field workers using the organophosphate chlorpyrifos." Thesis, Cattani, Marcus P.S. (2004) Exposures and health effects among field workers using the organophosphate chlorpyrifos. PhD thesis, Murdoch University, 2004. https://researchrepository.murdoch.edu.au/id/eprint/509/.
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Chlorpyrifos, an organophosphate pesticide moderately toxic to humans via inhalation and dermal absorption (LD50 oral, rat = 226 mg kg-1, LD50 skin, rabbits = 1265 mg kg-1), is widely used to eradicate termites in Australia. A series of 28 surveys totaling 32 separate assessments, or 10% of all professional users in Perth, Western Australia, comprised biological monitoring, exposure assessment techniques, a health symptoms and work practices questionnaire. Chlorpyrifos metabolite 3,5,6-trichloro-2-pyridinol and alkyl phosphates were extracted from urine, and serum cholinesterase (SChE) and erythrocyte acetylcholinesterase from blood. Chlorpyrifos was extracted from 24 patches removed from a supplied cotton overall, cotton gloves worn under protective gloves, 7 absorbent patches placed on the skin and an organic vapour collection tube. Surface wipes were collected in the workers vehicle and on the workers forehead. Chlorpyrifos was applied in either 0.5% (n=2) or 1% (n=26) concentration of active ingredient in water solution. Surveys took place at pre-construction sites (n=5) where pesticide was sprayed onto a prepared site, existing buildings with concrete foundations (n=17) where pesticide was injected under pressure around the perimeter of the building and existing buildings with suspended floors requiring the worker to spray under floor (n=6). Combined left and right glove deposition was 9 mg hour- 1 (SD = 18 mg.hour-1). Mean deposition on overalls was 14 mg.hour-1 (SD = 12 mg.hour-1), on skin patches was 0.2 mcg cm-1.hour-1, on vehicle gear-stick was 3 mcg (SD = 8 mcg) and, on steering wheels was 3 mcg (SD = 3 mcg). The mean protection 4 factor of overalls, a ratio of outer layer and inner levels, was 75 (SD = 411).
Mean air concentration of chlorpyrifos during an application was 30 mcg m-3, and 17 mcg m-3 8 hour TWA (SD = 40 mcg m-3 8 hour TWA), and in one group of 17 workers correlated (p<0.05) with ambient air temperature (15 to 38 oC). Urinary metabolites and SChE activity were effective indicators of exposure. The health symptoms questionnaire did not highlight significant health effects. A discrepancy between operators' perception of risk and their actual exposure requires addressing, for example the measured high deposition rate to hands was ineffectively controlled, as 48% or workers wore inappropriate or no gloves and only 26% washed their hands after completing their tasks. All workers indicated in the questionnaire they would wash their hands after completing their tasks. The questionnaire also highlighted a high incidence of poor work practices, 58% spilt the concentrate at least once a week, 74% had recently spilt/splashed diluted chlorpyrifos in their eyes and 90% on their boots, and 52% believed they would benefit from more education concerning chlorpyrifos. Observations concluded that workers unnecessarily increased their exposure by poor work practice.
Recommendations include modification to pesticide worker education, licencing and health surveillance systems; an improvement in the understanding of the benefits of a health and safety management systems for employers, and pesticide suppliers taking a stewardship role in the usage of their products.
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Cattani, Marcus P. S. "Exposures and health effects among field workers using the organophosphate chlorpyrifos /." Access via Murdoch University Digital Theses Project, 2004. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20040921.121425.
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Thesis (Ph.D.)--Murdoch University, 2004.Thesis submitted to the Division of Science and Engineering. Includes article published in Annals of Occupational Hygiene, 2001, v. 45 (4), p. 299-308. Bibliography: leaves 267-278.
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Wacksman, MItch. "Impact of atrazine on chlorpyrifos toxicity to four aquatic vertebrates /." Available to subscribers only, 2006. http://proquest.umi.com/pqdweb?did=1136077891&sid=35&Fmt=2&clientId=1509&RQT=309&VName=PQD.
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Hu, Xiaoyi. "Detection and quantitation of diazinon and chlorpyrifos : a novel GC." Scholarly Commons, 2002. https://scholarlycommons.pacific.edu/uop_etds/573.
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An analytical method was developed for detection and quantitation of diazinon and chlorpyrifos, two widely used pesticides in local water pathway. Solid phase extraction combined with GC/MS detection with selected ion monitoring was employed. In establishing calibration curves for GC/MS analysis, it may be impractical to use isotope-labeled analogs as internal standards for all analytes in a complicated matrix. Compounds may have to be used as internal standards which could cause non-linear effects because of different response of analytes and internal standards. A novel sample introduction method, which could eliminate this negative effect of non-linearity, was proposed. Calibration data were acquired using the traditional constant volume injection method, and a new method: constant mass injection of analytes. Calibration curves by the constant mass injection method show a better linearity and y-intercept. The nonlinear effect observed with data obtained in low concentration ranges using the constant volume injection method was eliminated. The effectiveness of these curves by two methods was also tested. Better accuracy was obtained with the constant mass injection method. This constant mass injection of analytes method could be very useful in
quantitative studies of a complicated sample matrix, such as those encountered in the environmental analysis of pesticides, or in the quality control analysis of medical and industrial product. In solid phase extraction, Varian Bondelute SPE C8 cartridge was selected for extraction. With the standard water sample spiked at 500 ng/L for the two analytes, the recovery for diazinon was about 50% and for chlorpyrifos about 60%. With the standard water sample at 1000 ng/L, the recovery for diazinon was about 60% and for chlorpyrifos about 70%. Among three samples from three different sampling sites, diazinon was detected and confirmed. The quantitation of diazinon was done to water sample from the Calaveras River near the Sanguetti Street crossing Stockton, California, with observed concentration 143.2 ng/L.
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au, marcus cattani@westnet com, and Marcus Paul Cattani. "Exposures and Health Effects among Field Workers using the Organophosphate Chlorpyrifos." Murdoch University, 2004. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20040921.121425.
Full textAbstract:
Chlorpyrifos, an organophosphate pesticide moderately toxic to humans via inhalation and dermal absorption (LD50 oral, rat = 226 mg kg-1, LD50 skin, rabbits = 1265 mg kg-1), is widely used to eradicate termites in Australia. A series of 28 surveys totaling 32 separate assessments, or 10% of all professional users in Perth, Western Australia, comprised biological monitoring, exposure assessment techniques, a health symptoms and work practices questionnaire. Chlorpyrifos metabolite 3,5,6-trichloro-2-pyridinol and alkyl phosphates were extracted from urine, and serum cholinesterase (SChE) and erythrocyte acetylcholinesterase from blood. Chlorpyrifos was extracted from 24 patches removed from a supplied cotton overall, cotton gloves worn under protective gloves, 7 absorbent patches placed on the skin and an organic vapour collection tube. Surface wipes were collected in the workers vehicle and on the workers forehead. Chlorpyrifos was applied in either 0.5% (n=2) or 1% (n=26) concentration of active ingredient in water solution. Surveys took place at pre-construction sites (n=5) where pesticide was sprayed onto a prepared site, existing buildings with concrete foundations (n=17) where pesticide was injected under pressure around the perimeter of the building and existing buildings with suspended floors requiring the worker to spray under floor (n=6). Combined left and right glove deposition was 9 mg hour- 1 (SD = 18 mg.hour-1). Mean deposition on overalls was 14 mg.hour-1 (SD = 12 mg.hour-1), on skin patches was 0.2 Ýg.cm-1.hour-1, on vehicle gear-stick was 3 Ýg (SD = 8 Ýg) and, on steering wheels¡¦ was 3 Ýg (SD = 3 Ýg). The mean protection 4 factor of overalls, a ratio of outer layer and inner levels, was 75 (SD = 411).
Mean air concentration of chlorpyrifos during an application was 30 Ýg m-3, and 17 Ýg m-3 8 hour TWA (SD = 40 Ýg m-3 8 hour TWA), and in one group of 17 workers correlated (p<0.05) with ambient air temperature (15 to 38 oC). Urinary metabolites and SChE activity were effective indicators of exposure. The health symptoms questionnaire did not highlight significant health effects. A discrepancy between operators¡¦ perception of risk and their actual exposure requires addressing, for example the measured high deposition rate to hands was ineffectively controlled, as 48% or workers wore inappropriate or no gloves and only 26% washed their hands after completing their tasks. All workers indicated in the questionnaire they would wash their hands after completing their tasks. The questionnaire also highlighted a high incidence of poor work practices, 58% spilt the concentrate at least once a week, 74% had recently spilt/splashed diluted chlorpyrifos in their eyes and 90% on their boots, and 52% believed they would benefit from more education concerning chlorpyrifos. Observations concluded that workers unnecessarily increased their exposure by poor work practice.
Recommendations include modification to pesticide worker education, licencing and health surveillance systems; an improvement in the understanding of the benefits of a health and safety management systems for employers, and pesticide suppliers taking a stewardship role in the usage of their products.
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Cattani, Marcus Paul. "Exposures and health effects among field workers using the organophosphate chlorpyrifos." Cattani, Marcus Paul (2004) Exposures and health effects among field workers using the organophosphate chlorpyrifos. PhD thesis, Murdoch University, 2004. http://researchrepository.murdoch.edu.au/509/.
Full textAbstract:
Chlorpyrifos, an organophosphate pesticide moderately toxic to humans via inhalation and dermal absorption (LD50 oral, rat = 226 mg kg-1, LD50 skin, rabbits = 1265 mg kg-1), is widely used to eradicate termites in Australia. A series of 28 surveys totaling 32 separate assessments, or 10% of all professional users in Perth, Western Australia, comprised biological monitoring, exposure assessment techniques, a health symptoms and work practices questionnaire. Chlorpyrifos metabolite 3,5,6-trichloro-2-pyridinol and alkyl phosphates were extracted from urine, and serum cholinesterase (SChE) and erythrocyte acetylcholinesterase from blood. Chlorpyrifos was extracted from 24 patches removed from a supplied cotton overall, cotton gloves worn under protective gloves, 7 absorbent patches placed on the skin and an organic vapour collection tube. Surface wipes were collected in the workers vehicle and on the workers forehead. Chlorpyrifos was applied in either 0.5% (n=2) or 1% (n=26) concentration of active ingredient in water solution. Surveys took place at pre-construction sites (n=5) where pesticide was sprayed onto a prepared site, existing buildings with concrete foundations (n=17) where pesticide was injected under pressure around the perimeter of the building and existing buildings with suspended floors requiring the worker to spray under floor (n=6). Combined left and right glove deposition was 9 mg hour- 1 (SD = 18 mg.hour-1). Mean deposition on overalls was 14 mg.hour-1 (SD = 12 mg.hour-1), on skin patches was 0.2 mcg cm-1.hour-1, on vehicle gear-stick was 3 mcg (SD = 8 mcg) and, on steering wheels was 3 mcg (SD = 3 mcg). The mean protection 4 factor of overalls, a ratio of outer layer and inner levels, was 75 (SD = 411).
Mean air concentration of chlorpyrifos during an application was 30 mcg m-3, and 17 mcg m-3 8 hour TWA (SD = 40 mcg m-3 8 hour TWA), and in one group of 17 workers correlated (p<0.05) with ambient air temperature (15 to 38 oC). Urinary metabolites and SChE activity were effective indicators of exposure. The health symptoms questionnaire did not highlight significant health effects. A discrepancy between operators' perception of risk and their actual exposure requires addressing, for example the measured high deposition rate to hands was ineffectively controlled, as 48% or workers wore inappropriate or no gloves and only 26% washed their hands after completing their tasks. All workers indicated in the questionnaire they would wash their hands after completing their tasks. The questionnaire also highlighted a high incidence of poor work practices, 58% spilt the concentrate at least once a week, 74% had recently spilt/splashed diluted chlorpyrifos in their eyes and 90% on their boots, and 52% believed they would benefit from more education concerning chlorpyrifos. Observations concluded that workers unnecessarily increased their exposure by poor work practice.
Recommendations include modification to pesticide worker education, licencing and health surveillance systems; an improvement in the understanding of the benefits of a health and safety management systems for employers, and pesticide suppliers taking a stewardship role in the usage of their products.
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Yan, Zhongyu. "Charaterization of Chlorpyrifos Toxicity on the Pancreatic Beta Cell Line RINm5f." Wright State University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=wright1290111576.
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Besson, Marc. "Importance of metamorphosis in coral-reef fish larval recruitment facing anthropogenic pressures." Thesis, Paris Sciences et Lettres (ComUE), 2017. http://www.theses.fr/2017PSLEP024/document.
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Le maintien et le renouvellement des populations de poissons coralliens dépendent en grande partie du recrutement larvaire, c’est-à-dire de l’installation des larves pélagiques dans les habitats récifaux adultes, et de leur survie après s’être métamorphosées en juvéniles. De plus en plus d’études révèlent que les changements de composition de l’eau, causés par le changement climatique et la pollution, peuvent altérer les capacités sensorielles des poissons coralliens, diminuant leurs aptitudes à localiser des habitats propices (maximisant leur croissance et diminuant leur mortalité) lors de l’installation. Cependant, les mécanismes internes à l’origine de ces phénomènes sont méconnus. Lors de cette thèse, j’ai examiné le recrutement larvaire du poisson chirurgien bagnard Acanthurus triostegus et mis en évidence que les changements écologiques, morphologiques, physiologiques et comportementaux qui s’y déroulent correspondent à une métamorphose contrôlée par les hormones thyroïdiennes (HT). J’ai ensuite analysé comment des stress d’origine anthropique, tels que l’élévation des températures de surface et la pollution par un pesticide d’origine agricole, peuvent perturber sa métamorphose. Lors de cette étape clé de leur cycle de vie, ces perturbations diminuent les taux d’HT, altérant la maturation de leurs organes sensoriels, leurs capacités sensorielles, et augmentant leur mortalité. Cette thèse est donc une analyse holistique de l’impact des perturbations anthropiques sur les processus moléculaires, et les changements histologiques, anatomiques et comportementaux du recrutement larvaire des poissons coralliens. Elle souligne l’importance du système thyroïdien, et invite à une meilleure compréhension des processus endocriniens du recrutement larvaire, dans l’optique d’une amélioration de la conservation des récifs coralliensThe persistence and sustainability of coral-reef fish populations depends on the continued larval recruitment, i.e. successful settlement by pelagic larvae into adult reef habitats and post-settlement survival through metamorphosis to a juvenile stage. There is growing evidence that changes to water conditions due to global change and waterborne pollution can impair coral-reef fish sensory abilities to locate settlement habitats that maximize growth while minimizing mortality risk. However, the inner mechanisms of such impairments remain unknown. In this thesis, I have examined the recruitment phase of the convict surgeonfish Acanthurus triostegus, and determined that the ecological, morphological, physiological and behavioral changes occurring at recruitment correspond to a metamorphosis mediated by thyroid hormones (TH). Then, I investigated whether this metamorphosis is prone to endocrine disruption under anthropogenic disturbances such as elevated sea water temperature and agricultural pesticide pollution. I demonstrated that such pressures can reduce TH levels at a critical developmental stage in coral-reef fishes, impairing their metamorphic processes such as intestine remodeling, sensory organ maturation, and sensory abilities acquisition, further increasing their mortality rates. Overall, this thesis is a holistic analysis that addresses molecular, histological, anatomical, and behavioral assays of multiple stressors affecting coral-reef fish recruitment. It indicates the importance of a proper endocrine function during coral-reef fish recruitment, highlighting the need for a better understanding of these processes for coral-reef conservation
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Xiao, Yunxiang III. "Dissipation and Leachability of Formulated Chlorpyrifos and Atrazine in Organically-amended Soils." Diss., Virginia Tech, 1997. http://hdl.handle.net/10919/29529.
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Bioremediation was studied in soils containing high concentrations of formulated chlorpyrifos (5 mg kg-1 Dursban® 4E) and atrazine (5 mg kg-1 AAtrex® 4L) using amendments including lignocellulosic sorbents, microbial nutrients (vegetable oil, corn meal and fertilizers), and microbial extracts from organic media previously exposed to these pesticides (chlorpyrifos and atrazine, respectively). Radiolabeled atrazine was used to examine the various dissipation routes in contaminated soil, also amended with lignocellulosic sorbents and microbial nutrients.
Both chlorpyrifos and atrazine dissipation from contaminated soils was enhanced by organic-based material amendments. The half-lives of chlorpyrifos based on extractability for soils unamended and amended with vegetable oil and peat moss were 87 and 52 days, respectively. The half-lives of atrazine in unamended and amended soil (vegetable oil, peat moss and fertilizers) were 175 and 40 days, respectively. The leachability of chlorpyrifos from contaminated soil was dramatically reduced by 82% during the first 30 days of incubation in treatments amended with vegetable oil and peat moss while only a 28% of reduction in leachability occurred in the corresponding unamended controls. Only a slight reduction of atrazine leachability was detected in amended treatments after 120 days of incubation.
Differences were found in the leachability of chlorpyrifos and atrazine when they were applied to soil either as technical grade or formulated material. The presence of surfactants and other adjuvants in formulated chlorpyrifos (Dursban® 4E) reduced chlorpyrifos leachability in contaminated soil. Chlorpyrifos leachability was reduced by 43% in the formulated chlorpyrifos treatments, whereas there was a negligible decrease in technical chlorpyrifos treated soil during the first 3 days after contamination. Atrazine extractability and leachability was not affected by its formulation (AAtrex® 4L).
Amendments with lignocellulosic sorbents and nutrients decreased atrazine®s volatility from contaminated soils. After 16 weeks of incubation, less than 1% of 14C-atrazine was volatilized from incubated soils. Overall, after 16 weeks of incubation less than 4% of 14C-atrazine was mineralized and more radioactivity was recovered from amended treatments than unamended treatments as 14CO2. The major portion of radioactivity (62%) was associated with physisorbed atrazine represented by the ethylacetate extract I from unamended treatments while only 28% of initial applied radioactivity was recovered in the corresponding amended treatments. Based on the sum of radioactivity in humic and fulvic acids, approximately 14% of radioactivity was incorporated or chemisorbed atrazine and its metabolites in both unamended and amended treatments. Forty-five percent of the initially applied radioactivity was associated with alkali insoluble fraction in amended treatments but only 17% of the initially applied radioactivity was detected in the corresponding unamended treatments. Less than 2 % of initial activity associated with physisorbed portions of fulvic acids and alkaline insoluble fraction indicated as the radioactivity in methylene chloride and ethylacetate extract II . Over time, more radioactivity was associated with polar atrazine hydroxylated degradation products.Ph. D.
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De, Wet Owen. "Susceptibility of five strains of vine mealybugs, Planococcus ficus (Signoret), to chlorpyrifos." Thesis, Stellenbosch : Stellenbosch University, 2004. http://hdl.handle.net/10019.1/70289.
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Thesis (MScAgric)--Stellenbosch University, 2004.ENGLISH ABSTRACT: Colonies of Planococcus ficus (Signoret) were reared from three different areas, Hex River Valley, Robertson and Stellenbosch. An insectary colony and a table grape colony from Nietvoorbij experimental farm were also included in the study. A range of concentrations of chlorpyrifos was applied topically to individuals from the different colonies. The Stellenbosch population had the lowest LDso, although it was not significantly different from that of the insectary and Robertson colonies. The Hex River Valley and table grape colonies had a significantly higher LDso than the Robertson, Stellenbosch and insectary colonies, although the relative tolerance was 1.5, which would probably not result in significant control failure in the field. However, this does indicate that there is potential for the development of resistance to chlorpyrifos in the vine mealybug in South Africa.
AFRIKAANSE OPSOMMING: Kolonies van Planococcus ficus (Signoret), is versamel en geteel uit drie verskillende areas, Hex.riviervallei, Robertson en Stellenbosch. 'n Bestaande insektarium kolonie van die Lanbou Navorsings Raad en 'n tafeldruif kolonie vanaf Nietvoorbij proefplaas is ook ingesluit in die studie. 'n Reeks konsentrasies van chlorpyrifos is topikaal aangewend aan individue van die verskillende kolonies. Die Stellenbosch populasie het die laagste LDso getoon alhoewel dit nie betekenisvol verskil het van die LDso van die insektarium - en Robertson kolonies nie. Die Hexriviervallei en tafeldruif kolonies se LDso was betekenisvol hoër as die Robertson, Stellenbosch and insektarium kolonies. Alhoewel die relatiewe weerstand 1.5 was, sal dit waarskynlik nie tot 'n aansienlike beheermislukking in die veld lei nie. Nogtans dui dit op die potensiaal vir moontlike ontwikkeling van weerstand teen chlorpyrifos in die wingerdwitluis.
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Karakoyun, İnanç Gültekin Fatih. "Chlorpyrifos uygulanmasının akut dönemde hipokampusta NMDA 2A ve 2B reseptörleri düzeyine etkisinin incelenmesi /." Isparta : SDÜ Tıp Fakültesi, 2005. http://tez.sdu.edu.tr/Tezler/TT00189.pdf.
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Pittman, Julian Thomas. "Changes in the Murine Nigrostriatal Pathway Following Pyrethroid and Organophosphate Insecticide Exposure: An Immunohistochemical Study." Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/34864.
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Parkinson's disease (PD) is a debilitating motor disorder that primarily afflicts older individuals (> 50yrs). Although its cause is unknown, many factors are thought to contribute to the disease. There is growing epidemiological evidence supporting a link between pesticide exposure and PD. The present immunohistochemical study was undertaken to characterize the role of insecticide exposure in the etiology of idiopathic PD. The insecticides selected for study were the pyrethroid permethrin (PE) and the organophosphate chlorpyrifos (CP), both of which possess properties that could damage or disrupt the nigrostriatal pathway, which is the principal neurodegenerative target in PD. The present study examined possible alteration of the amount of dopamine re-uptake transporter protein (DAT), within the striatum of the C57BL/6 mouse, using DAT antibodies, following low (0.8, 1.5 & 3.0 mg/kg) and high (200 mg/kg) doses of PE, respectively. Possible nigrostriatal terminal degeneration was examined using antibodies to tyrosine hydroxylase (TH), the rate-limiting enzyme in dopamine synthesis, following treatment with 50 mg/kg of CP alone or in combination with the high dose of PE. For both the high dose of PE alone and for the combined PE/CP treatment, glial fibrillary acidic protein (GFAP) antibodies were used to examine the possibility of non-degenerative tissue injury. Groups of matched treated/vehicle-control mice received three IP injections of the insecticide/dose of interest over a 2-week period. Counts of immunoreactive (IR) neuropil in the dorsolateral striatum were made from four pre-selected fields per striatal tissue section. Counts were compared between matched sections, processed on the same slide, from a treated mouse and its vehicle control. A mean difference score, across slides, for each treated/vehicle control pair was determined. All low dose PE groups showed a trend of decreased DAT IR neuropil, but only the 3.0mg/kg group showed a statistically significant reduction (p<.0078). The 200 mg/kg PE group showed a trend toward reduced TH IR neuropil that was not statistically significant, but a significant increase in GFAP IR (p = .048) was observed. No significant change in TH IR neuropil was observed for CP (50mg/kg) alone. A significant increase was observed for GFAP IR neuropil for the PE/CP (200/50 mg/kg) combination dose (p = .033). The combined insecticide treatment failed, however, to produce a significant change in TH IR within the striatum, compared to vehicle controls. These data suggest that the significant increases in GFAP IR neuropil, in the striatum, reflect some form of tissue insult, following exposure to a high dose of PE, or PE/CP in combination, that is insufficient to induce degeneration of dopaminergic terminals within the temporal interval investigated. Although such damage may be sufficient to account for previously reported decreases in maximal dopamine uptake observed with high doses of these compounds, the DAT IR data appear to indicate that this damage is unlikely to be a change in the amount of DAT in these high dose conditions. The decreases in striatal DAT IR neuropil observed for low doses of PE suggest an alteration in the normal integrity of the nigrostriatal pathway and in the route by which environmental toxins may enter dopaminergic neurons.Master of Science
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Peris, Sampedro Fiona. "Apoe phenotype expression and its modulation by chlorpyrifos: new insights into gene - toxic interactions." Doctoral thesis, Universitat Rovira i Virgili, 2016. http://hdl.handle.net/10803/346635.
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L'ús extensiu i l'abocament massiu de pesticides en el medi ambient ha portat a alguns autors a preguntar-se sobre la contribució d'aquestes substàncies al desenvolupament de trastorns neuropsiquiàtrics i metabòlics. Actualment, els organofosforats (OP) - i el clorpirifos (CPF) en particular - són els insecticides més emprats al món. Donada la diversitat de fonts d'exposició, la majoria de la població està exposada gairebé permanentment a CPF. Una gran quantitat d’estudis epidemiològics i experimentals han observat dèficits neuroconductuals després de l'exposició al pesticida, i evidències incipients suggereixen vincles entre l'exposició a OPs i el desenvolupament de trastorns metabòlics. Una de les claus consisteix a establir si existeixen subpoblacions particularment susceptibles als efectes perjudicials del CPF. S'ha demostrat que les diferents isoformes de l'apolipoproteïna E (apoE) humana confereixen diferents vulnerabilitats a desenvolupar malalties metabòliques i neurodegeneratives. El principal objectiu d'aquesta tesi va ser avaluar els efectes comportamentals i metabòlics del genotip APOE i del CPF, així com determinar si la interacció entre ambdós factors va contribuir a l'aparició d'aquests efectes. Amb aquest propòsit, ratolins adults portadors de apoE2, apoE3 o apoE4 foren exposats subcrònicament a 2 mg/kg/dia o 3.75 mg/kg/dia de CPF en funció de la fase experimental. Després de l'exposició, els animals foren avaluats conductualment, mentre que els efectes metabòlics del CPF també foren avaluats en paral·lel. En general, el genotip APOE va influenciar el rendiment cognitiu. L'exposició a CPF va alterar el funcionament metabòlic, i va induir dèficits atencionals i motivacionals prolongats en el temps. Els ratolins apoE3 foren els més vulnerables als efectes metabòlics del tòxic, i van mostrar alteracions de la memòria després de l'exposició. A més, el pesticida va invertir el dèficit de control inhibitori característic dels ratolins apoE4. En conclusió, aquests resultats amplien la literatura existent sobre els efectes comportamentals i metabòlics del CPF, i proporcionen informació valuosa sobre interaccions gen - tòxic fins ara desconegudes.El uso extensivo y el vertido masivo de pesticidas en el medio ambiente ha llevado a algunos autores a preguntarse sobre la contribución de estas sustancias al desarrollo de trastornos neuropsiquiátricos y metabólicos. Actualmente, los organofosforados (OPs) - y el clorpirifos (CPF) en particular - son los insecticidas más utilizados en el mundo. Dada la diversidad de fuentes de exposición, la mayoría de la población está expuesta casi permanentemente a CPF. Una gran cantidad de estudios epidemiológicos y experimentales han observado déficits neuroconductuales tras la exposición al pesticida, y evidencias incipientes sugieren vínculos entre la exposición a OPs y el desarrollo de trastornos metabólicos. Una de las claves consiste en establecer si existen subpoblaciones particularmente susceptibles a los efectos perjudiciales del CPF. Se ha demostrado que las diferentes isoformas de la apolipoproteína E (apoE) humana confieren diferentes vulnerabilidades a desarrollar enfermedades metabólicas y neurodegenerativas. El principal objetivo de esta tesis fue evaluar los efectos comportamentales y metabólicos del genotipo APOE y del CPF, así como determinar si la interacción entre ambos factores contribuyó a la aparición de estos efectos. Así, ratones adultos portadores de apoE2, apoE3 o apoE4 fueron expuestos subcrónicamente a 2 mg/kg/día o 3.75 mg/kg/día de CPF en función de la fase experimental. Tras la exposición, los animales fueron evaluados conductualmente, mientras que los efectos metabólicos del CPF también fueron estudiados en paralelo. En general, el genotipo APOE influenció el rendimiento cognitivo. La exposición a CPF alteró el funcionamiento metabólico, e indujo déficits atencionales y motivacionales prolongados en el tiempo. Los ratones apoE3 fueron los más vulnerables a los efectos metabólicos del tóxico, y mostraron alteraciones de la memoria tras la exposición. Además, el pesticida invirtió el déficit de control inhibitorio característico de los ratones apoE4. En conclusión, estos resultados amplían la literatura existente sobre los efectos comportamentales y metabólicos del CPF, y proporcionan información valiosa sobre interacciones gen - tóxico hasta ahora desconocidas.
The extensive use and massive release of pesticides into the environment has led some authors wonder about the potential contribution of these substances on the emergence of neuropsychiatric and metabolic disorders. Currently, organophosphates (OP) – and chlorpyrifos (CPF) in particular - are the most widely used insecticides in the world. Given the heterogeneity of sources of exposure, most of the population is almost permanently exposed to CPF. Thus, a great body of epidemiological and experimental data have reported neurobehavioural deficits following exposure to the pesticide, and incipient evidence begins to suggest potential links between OPs and metabolic disorders. One of the critical issues is to establish whether there are subpopulations particularly susceptible to the detrimental effects of CPF. It has been proved that human apolipoprotein E (apoE) isoforms confer on their carriers varying vulnerabilities to metabolic diseases and neurodegeneration. The main objective of this thesis was to assess the behavioural and metabolic effects of both APOE genotype and CPF, as well as to determine whether the interaction between both factors contributed to these effects. To test this, adult mice expressing apoE2, apoE3 or apoE4 human isoforms were subchronically exposed to 2 mg/kg/day or 3.75 mg/kg/day CPF depending on the experimental phase. After exposure, animals were behaviourally tested, while the metabolic-disruptor role of CPF was also assessed in paralel. In general, APOE genotype influenced cognitive performance. The exposure to CPF altered metabolic functioning, and induced protracted attentional and motivational deficits. ApoE3 mice were the most vulnerable to the metabolic effects of CPF, and showed memory impairments after exposure. Furthermore, the pesticide reversed the lack of inhibitory control characteristic of apoE4 mice. Taken together, these results expand the existing literature on the behavioural and metabolic effects of CPF, and provide valuable information on gene – toxic interactions hitherto unknown.
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Forslund, Annica. "Investigation of developmental neurotoxic effects of exposure to a combination of methylmercury and chlorpyrifos." Thesis, Uppsala universitet, Institutionen för biologisk grundutbildning, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-341295.
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Adams, P. H. "Laboratory studies on two radiolabelled insect control agents : juvenile hormone III and chlorpyrifos-methyl." Thesis, University of Reading, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356759.
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Atabila, Albert. "Human Health Risk Assessment and Management of Chlorpyrifos Exposure among Rice Farmers in Ghana." Thesis, Griffith University, 2017. http://hdl.handle.net/10072/378754.
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Pesticides are commonly applied in the agricultural sector of Ghana by farmers. Owing to weaknesses in regulations and unsafe practices, applicators of pesticides in the country are vulnerable to excessive exposure and consequent health risks. However, there is no information on the levels of pesticide exposure and associated health risks among applicators in Ghana. In addition, the rice sector of Ghanaian agriculture has been growing in recent years, with significant use of pesticides among commercial growers. Therefore, the objectives of this study were to evaluate the patterns, determinants, magnitude and health risks of pesticide exposure among rice farmers in Ghana. In order to achieve the objectives, a representative cross-section of small-scale farmers who grow rice with irrigation in the catchment area of Kpone Irrigation Scheme (KIS) were recruited for the study. The research was based on the four-step health risk assessment framework of the United States’ National Research Council, which is generally accepted by regulatory agencies and researchers. Thus, the research involved hazard identification, exposure assessment, dose-response assessment and risk characterization. The hazard identification study with the farmers (n = 214), which was carried out by questionnaire survey, showed that chlorpyrifos was the most widely used pesticide with usage prevalence of 83%. The study also showed that pesticides were applied under unsafe conditions and all applicators had experienced symptoms compatible with pesticide poisoning, as described by the WHO. Evaluation of exposure to chlorpyrifos among the applicators during a typical spray event was carried out, based on two approaches. These were (1) whole-body dosimetry assessment of dermal exposure, using Tyvek coverall, hand gloves and socks to sample chlorpyrifos residues of applicators (n = 24); and (2) urinary trichloro-2-pyridinol (TCP) assessment of overall exposure from six urine samples (one sample collected prior to application and five samples collected over five days after application) from each applicator (n = 21). The dermal exposure study showed that the percentage Unit Exposure (UE) value calculated from Total Dermal Exposure (TDE) was 0.03% and 0.06% among the median-exposed and the 5% highly-exposed groups, respectively. The study also indicated that the hands (39% of TDE) and the lower anatomical (82% of TDE) regions of the applicators were the most contaminated and potential sources of dermal exposure. The urinary TCP assessment indicated that the mean elimination half-life (t1/2) of chlorpyrifos in the body of the applicators was 50 hours, which is higher than those (27 to 43 hours) previously reported. The median absorbed dose of chlorpyrifos estimated from urinary TCP due to chronic background exposure (LADDB), chronic application exposure (LADDA) and acute application exposure (ADDA) were 0.2 μg/kg/day (mean ± S.D of 0.3 ± 0.4 μg/kg/day), 0.1 μg/kg/day (mean ± S.D of 0.3± 0.3 μg/kg/day) and 6 μg/kg/day (mean ± S.D of 19 ± 24 μg/kg/day). The absorbed daily dose of chlorpyrifos estimated from urinary TCP and whole-body dermal dosimetry methods produced similar exposure estimates, based on the means ± S.D (15±22 and 16±7 μg/kg/day, respectively), with applicators who participated in both evaluations. The levels of chlorpyrifos exposure from occupational application were positively influenced by the quantity of chlorpyrifos formulation applied, spraying duration, the number of spray tanks applied and the height of the crops sprayed (p < 0.05). To evaluate the dose-response of chlorpyrifos, exposure data from human epidemiological studies from the scientific literature were collated. The exposure data associated with adverse effects were expressed as Cumulative Probability Distributions (CPDs) to obtain the Toxicant Sensitivity Distributions (TSDs) of chlorpyrifos for chronic and acute adverse effects. A guideline value determined at the 5th percentile of the TSD for chronic and acute adverse effects was 0.5 and 2 μg/kg/day, respectively. These guideline values derived with the TSD method are directly applicable to humans without the need for safety factors. On the other hand, conventional guideline values established by regulatory institutions require the application of safety factors when the No Observable Adverse Effect Level (NOAEL) or Lowest Observable Adverse Effect Level (LOAEL) methods are used. Except for the guideline values set by the WHO which gave HQ < 1, those of the USEPA, APVMA and the TSD threshold dose at the 5th percentile gave HQ > 1, suggesting adverse health effects would be observed among the applicators. The percentages of the applicators who were likely to suffer adverse effects due to chlorpyrifos exposure were quantified with the Overall Risk Probability (ORP) and the Monte Carlo Simulation (MCS) techniques. The ORP and the MCS techniques showed that between 1 to 3%, 2 to 4% and 5 to 8% of the applicators were likely to suffer chronic adverse effects due to chlorpyrifos exposure from background, occupational application and combined exposure from background and occupational application, respectively. Such chronic health effects may include altered thyroid functions and reductions in estradiol levels, based on the TSD. Also, the ORP and MCS techniques showed that between 31 to 33% and 32 to 34% of the applicators were likely to suffer acute health effects due to exposure from occupational application and combined exposure from background as well as occupational application, respectively. Comparison of these values with the TSD suggests that the acute health effects likely to be suffered by the applicators can include depression of cholinesterase activity, sub-clinical neuropathy and memory problems, particularly with occupational exposure. Recommendations proposed for adoption by government institutions to help reduce pesticide exposure and associated health effects among the applicators, include provision of training and technical services to enhance adoption of Integrated Pest Management (IPM), promoting use of less toxic pesticides, regular training of farmers and Agricultural Extension Officers (AEOs) on pesticide safety and regular monitoring of exposure among applicators. It is also recommended that farmers should avoid excessive pesticide use, reduce spray duration, reduce number of spray tanks, practice good hygiene and use adequate PPE, particularly for the hands and the lower anatomical regions of the body.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environment and Sc
Science, Environment, Engineering and Technology
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Dodd, Celia Anne. "Synthetic and Natural Environmental Compounds as Potential Facilitators of Mptp-Induced Parkinsonism." Diss., Virginia Tech, 2009. http://hdl.handle.net/10919/26359.
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Parkinson's disease (PD) is a neurodegenerative Lewy body disorder characterized by severe motor deficits, followed by cognitive dysfunction with progression of the disease. Environmental exposure has been suggested as a possible contributor to the development of PD and this view is linked to the discovery of the nigrostriatal neurotoxin MPTP. MPTP can induce dopamine specific degeneration within the basal ganglia often resulting in motor deficits similar to PD. MPTP used in the C57BL/6 mouse is a widely used animal model of PD. The pyrethroid permethrin (PM), and the organophosphate chlorpyrifos (CPF), can produce changes in dopaminergic nigrostriatal neurons, the primary target of PD and MPTP-induced neurotoxicity. Such insecticide induced changes in the basal ganglia could exacerbate the onset or severity of PD. Chronic exposure to the metal manganese (Mn) can damage the globus pallidus (GP) of the BG, and produce motor deficits similar to PD. Since the GP is part of the BG circuitry essential for motor control, and is synaptically integrated with the nigrostriatal pathway, Mn may exacerbate MPTP-induced neurotoxicity. Because the BG is disynaptically linked to the mesocortical pathway, a dopaminergic pathway that is important for cognition, Mn induced damage in the BG could indirectly affect the mesocortical pathway as well. This study investigated the pesticides, permethrin and chlorpyrifos, and the heavy metal, manganese as possible environmental compounds that could exacerbate PD in the MPTP treated C57BL/6 mouse.
The first part of this dissertation used immunohistochemistry to examine insecticide induced effets on MPTP-induced neurotoxicity in the dorsolateral striatum of the C57BL/6 mouse, the principal target of the nigrostriatal pathway. Tyrosine hydroxylase (TH) was used as a marker for loss of dopaminergic neuropil and glial fibrillary acidic protein (GFAP) was used as a marker of glial activation in the striatum. Three experiments assessed effects of 1) PM (200 mg/kg), 2) CPF (50 mg/kg) & 3) PM + CPF, on MPTP (30 mg/kg) neurotoxicity. Immunohistochemistry revealed a decrease in TH staining and an increase in GFAP staining with MPTP (30 mg/kg). A main effect increase in GFAP was observed for PM (200 mg/kg), but not for CPF (50 mg/kg) or PM+CPF. Insecticides, alone or combined, did not alter MPTP-induced toxicity. . However, the absence of the PM-induced increase in GFAP staining following combined insecticide treatment suggests a neuroprotective effect.
The next set of experiments in this dissertation looked at the effect of Mn on MPTP-induced neurotoxicity in the nigrostriatal and mesocortical dopaminergic pathways of the C57BL/6 mouse. Inductively Coupled Plasma atomic emission spectrometry revealed striatal Mn levels were significantly increased with multiple dose 100, 50, and 25 mg/kg MnCl2. Administration of Mn (MnCl2 s.c., Days 1, 4, & 7) in the MPTP (20 mg/kg i.p., Day 8) treated C57BL/6 mouse revealed Mn and MPTP interactions for locomotor activity, grip strength, and repeated measures of learning. Mn attenuated the effect of MPTP on striatal DOPAC, and facilitated the effect of MPTP on cortical DA and DOPAC. Mn also attenuated the MPTP induced decrease in cortical DAT. While these data support the notion that insecticides can produce tissue damage in the nigrostriatal pathway, in this case, these insecticide induced changes were not found to be strong enough to facilitate PD-like tissue damage. While Mn did not always facilitate MPTP neurotoxicity in the mesocortical and nigrostriatal dopaminergic pathways, these results demonstrate Mn and MPTP can interact in a complex way to alter dopaminergic function as well as motor and cognitive behavior. Differences in brain uptake mechanisms and metabolism of Mn and MPTP, could explain why combined administration of Mn and MPTP differentially affect dopaminergic activity in the nigrostriatal and mesocortical pathways.Ph. D.
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Pung, Thitiya. "Neurochemical Effects of Concurrent Exposure to Repeated Stress and Chlorpyrifos on the Central Nervous System." Diss., Virginia Tech, 2004. http://hdl.handle.net/10919/29101.
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Repeated stress has been reported to cause reversible impairment to the hippocampus. Glutamatergic and cholinergic systems were proposed to be involved in responses seen after exposure to stress and cholinesterase inhibitors. Effects of concurrent exposure to repeated stress and chlorpyrifos (CPF) on concentrations of excitatory amino acids, activities of cholinergic enzymes, and maximum binding density (Bmax) and equilibrium dissociation rate constant (Kd) of NMDA and total muscarinic receptors were studied in Long-Evans rats. The study was divided into 4 experiments. The first experiment was to find the dose of CPF to use for studies on the interaction of stress and CPF. From the results obtained, 60% of the maximum tolerated dose was chosen. An experiment to determine effects of repeated stress and CPF on cholinergic enzymes and glutamate included groups of rats (n=7-8) that were handled 5 days/week; restrained 1 hour/day for 5 days/week; swum 30 minutes for 1 day/week; or restrained 4 days/week and swum for 1 day/week, for 28 days. On day 24, each group was injected either with corn oil or CPF 160 mg/kg sc 4 hours after restraint. On day 28, blood samples were collected for acetylcholinesterase (AChE) activity. Brains were dissected into hippocampus (HP) and cerebral cortex (CC) to determine activities of acetylcholinesterase (AChE), carboxylesterase (Cbxy), and choline acetyltransferase (ChAT), and glutamate and aspartate concentrations. CPF inhibited AChE activity in blood, CC and HP, but stress did not affect AChE activity. Repeated restraint with swim reduced Cbxy and CPF inhibited Cbxy. Restraint with swim had a statistical trend to increase concentrations of glutamate in the HP more than swim alone (p = 0.064); but CPF had no effect on glutamate in the HP. CPF decreased concentrations of elevated aspartate in the HP of rats that were restrained and swum. The results suggested that restraint with swim indirectly elevated acetylcholine in the CC, and tended to increase glutamate in the HP. The experiment designed to study the effects of concurrent exposure to stress and CPF on NMDA and total muscarinic receptors was designed similar to the previous study, except that endpoints were Bmax and Kd of NMDA and total muscarinic receptors in the HP and CC, and NMDA receptors in the hypothalamus (HT). Restrained rats had higher Kd of NMDA receptors in the HP than control and restrained with swim rats; however, Bmax was similar. CPF deceased Bmax and Kd of total muscarinic receptors in the CC of swum rats (237.64 ± 17.36 fmol/mg protein, 0.216 ± 0.023 nM) and CPF also decreased Bmax of total muscarinic receptors in the CC of restrained rats (229.08 ± 17.36 fmol/mg protein). There were no effects of stress, CPF, or interactions of stress and CPF on NMDA receptors in the CC or on total muscarinic receptors in the HP. In summary, CPF was capable of modulation of total muscarinic receptors of swum and restrained rats, suggesting that cholinergic transmission in the CC for cognition, sensory and motor activity may be modified. Furthermore, we examined effects of stress and CPF on concentrations of monoamines. Swim stress and CPF individually decreased concentrations of norepinephrine in the HP, whereas swim and restraint with swim decreased concentrations of norepinephrine but increased concentrations of DOPAC in the HT. Swim stress increased concentrations of dopamine in the HT more than control or restraint. CPF did not alter concentrations of norepinephrine, dopamine, or DOPAC in the HT. The interactions of repeated stress and CPF on serotonin approached significance in the HP (p = 0.06) and HT (p = 0.08). CPF increased serotonin concentrations in rats that were handled and restrained but not swum. CPF reduced the elevated concentrations of serotonin in restrained rats and restrained with swim rats (p < 0.05). Swim and restraint with swim were potential stress models that altered noradrenergic, dopaminergic, and serotonergic responses in the HT. In summary, repeated stressors had effects on glutamatergic, cholinergic, and monoamine systems. CPF had effects on cholinergic and monoamine systems but the interactions between stress and CPF were few.Ph. D.
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Ricker, Justin T. "Inhibition of OV2008 Cancer Cell Proliferation in the Presence of Oleoylethanolamide, JW480 and Chlorpyrifos-oxon." Kent State University Honors College / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ksuhonors1450797277.
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Judge, David Nixon. "Studies concerning the fate of atrazine and chlorpyrifos in a biobased pesticide waste disposal system." Diss., This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-08272007-163645/.
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Zalizniak, Liliana, and liliana zalizniak@rmit edu au. "The effects of selected agricultural chemicals on freshwater microalgae and cladocerans in laboratory studies, with particular emphasis on hormesis." RMIT University. Applied Sciences, 2007. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20080618.091930.
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This thesis examines the toxicity of the herbicide glyphosate (two formulations ¡V technical grade and Roundup Biactive RB) and the insecticide chlorpyrifos CPF to a model freshwater food chain of a producer and consumer. The importance of studying the toxicity of low (environmentally realistic) concentrations of pesticides to non-target organisms is highlighted. An extensive literature review on the toxicity of glyphosate and chlorpyrifos to aquatic organisms is provided. The requirements for the maintenance of algal (Chlorella vulgaris, Chlorella pyrenoidosa and Pseudokirchneriella subcapitata) and Daphnia carinata cultures are discussed. The effects of two formulations of the herbicide glyphosate (technical grade and Roundup Biactiveµ) and the insecticide chlorpyrifos on the growth of Chlorella pyrenoidosa and Pseudokirchneriella subcapitata were studied, and the EC50 values determined. Hormesis was observed when P. subcapitata was exposed to concentrations of Roundup equal to 7% and 4% of its EC50 respectively. When exposed to chlorpyrifos concentrations 0.3-5 Ýg/L, hormesis was observed for both algal species with a maximum at 0.06% of EC50. The effects of sublethal concentrations of chlorpyrifos on population characteristics of Daphnia carinata were investigated in multiple-generation toxicity testing using individual culture. Exposure to chlorpyrifos affected survival and fecundity of animals in the first generation. In the second generation the most affected endpoint was time to the first brood with an indication of hormesis. LC50 tests were then conducted using animals of the third generation from each of the exposures in individual tests. Results of testing the third generation showed a constant significant decline in LC50 in the order of control daphnids through to ¡¥0.1 LC50¡¦ pre-exposed daphnids. The same experimental protocol was used in testing of glyphosate (technical grade and Roundup Biactive). Glyphosate was tested in two different media: sea salt solution and M4 medium, while Roundup Biactive was tested in M4 medium. Results indicated that glyphosate and Roundup Biactive had low toxicity to Daphnia. Hormesis was evident in sea salt medium exposures in the first and second generations of daphnids with glyphosate. When exposed to glyphosate and Roundup Biactive in M4 medium animals showed no indication of hormesis. It is hypothesized that glyphosate may have compensated for the lack of microelements in the sea salt medium, and possible mechanisms discussed.The modifying effect of glyphosate on the toxicity of cadmium to Daphnia carinata was studied using the same experimental design. Low concentrations of Roundup Biactive reduced the toxicity of cadmium, and the performance of daphnia was enhanced in terms of animal size, survival, fecundity, and the rate of natural increase in both generations in the presence of glyphosate. However when the third generation was tested for their sensitivity to Cd in the 48-h LC50 experiments there was no difference between RB-free and RB-spiked treatments in pair wise comparisons, indicating that no adaptation mechanisms were involved in the enhancement. The implications of these observed effects for environmental freshwater food chains subjected to pesticide exposure are discussed and recommendations on modifying pesticide use are provided.
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Sun, Jinchun. "A MASS SPECTROMETRY-BASED STUDY OF SERUM BUTYRYLCHOLINESTERASE INHIBITION FROM PESTICIDE EXPOSURE AND ORGANOPHOSPHATE PESTICIDE-INDUCED PROTEOME ALTERATION." UKnowledge, 2006. http://uknowledge.uky.edu/gradschool_diss/290.
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Pesticides including organophosphates (OPs) and carbamates (CBs) are widelyused to control undesirable pests. These compounds are neurotoxic and inhibithydrolysis of the neurotransmitter acetylcholine by acetylcholinesterase. Public healthconcerns have increased with the escalating usage of pesticides. Reliable monitoringprograms are required to detect and quantify pesticide exposure, as well as to promotean understanding of their neurotoxic properties. In this dissertation, both theanticholinergic (Part I) toxicity and neurotoxicity in neuroblastoma cells (Part II) ofpesticides were explored using mass spectrometry (MS). The high sensitivity andhigh-throughput of this technique renders it well-suited for proteomics analysis.Part I describes the study of butyrylcholinesterase (BChE) inhibition resultingfrom OP and CB exposure. The main hypothesis of Part I is that the specialmodification of BChE can provide the origin and extent of pesticide exposure. A novelmethod for detection and quantification of pesticide exposure was designed using aproteomics approach and equine BChE (eBChE) as a model system. The methodologyfeatured detection and analysis of phosphorylated or carbamylated peptides at theactive site serine residue. The developed technique was successfully applied towardsthe study of human BChE (hBChE) inhibition in vitro and in serum samples. Aspecially designed affinity column enabled an isolation of BChE from serum. EnrichedBChE was subjected to enzymatic digestion by a novel on-bead double digestionprotocol. LC/MS/MS was employed to produce a calibration system for the analysis ofhBChE inhibition, which was then applied towards quantification of the enzyme.Part II describes a proteomic study of the neurotoxicity in neuroblastoma cellscaused from chlorpyrifos (CPF), an organophosphate pesticide. The concerns of CPFexposure to pregnant women, infants and children are increasing due todevelopmentally neurotoxic effects of this chemical. The main hypothesis of Part II isthat CPF can cause protein alterations and these altered proteins can be detected usingproteomics. Systematic studies at subcellular levels evaluated proteome changes inSH-SY5Y cells exposed to CPF. Two-dimensional gel electrophoresis (2DE) wasapplied with MALDI-TOF-MS to analyze differential protein expression. Thirty sevencommon unique altered proteins were identified, which play important roles inmetabolic pathway.
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Martins, Cátia Ariana Henriques. "Toxicity assessment and prediction of a realistic pesticide mixture from a portuguese agricultural area using concentration-response surface statistics." Master's thesis, ISA-UL, 2016. http://hdl.handle.net/10400.5/13382.
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Mestrado em Engenharia do Ambiente - Instituto Superior de Agronomia - ULPrevious work showed the co-occurrence of the organophosphate chlorpyrifos and the striazine herbicide terbuthylazine in surface waters of agricultural areas in “Lezíria do Tejo”, Portugal. In the present study, we examine the effects of these pesticides singly and as a binary mixture on the immobility of Daphnia magna and on the growth rate of the microalgae Pseudokirchneriella subcapitata. Terbuthylazine and chlorpyrifos at single exposure caused a very toxic or toxic response in both organisms. Usually, the toxicity of mixtures is evaluated in relation to the reference models Concentration Addition (CA) and Independent Action (IA). Initially, in this study was used the CA and IA model was to evaluate the joint effects of chlorpyrifos and terbuthylazine. For immobility endpoint, the data fits better to the IA model, due to different mode of action of the pesticides, however a specific pattern was showed; at low dose levels the immobility was lower than modelled (antagonism), whereas at high dose levels the immobility was higher than modelled (synergism). On the other hand, no deviation was observed from independent action in algal tests. This study represents an important step to understand the interactions among pesticides detected previously in field monitoring studies of agricultural areas in “Lezíria do Tejo”, Portugal. Observed mixture toxicity was compared with predictions, calculated from the concentration response functions of chlorpyrifos and terbuthylazine at two realistic concentration ratios by applying the biologically relevant patterns in which deviations occurred. The assumption of these last yielded accurate predictions, although worst for the mixture ratio chlorpyrifos 0.17 and terbuthylazine 85 μg/L under consideration.
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Oliveira, Andrà Gadelha de. "RemoÃÃo do AgrotÃxico Organofosforado ClorpirifÃs usando Processo Oxidativo AvanÃado." Universidade Federal do CearÃ, 2011. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=6175.
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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgicoO presente trabalho estudou o uso de processo oxidativo avanÃado para a remoÃÃo do agrotÃxico organofosforado clorpirifÃs. Para tanto, sistema de reator em escala laboratorial e escala piloto foram estudados. Na primeira etapa, em escala laboratorial, foram realizados estudos dos parÃmetros temperatura, pH e dosagem do perÃxido de hidrogÃnio, concentraÃÃo do agrotÃxico e efeito inibitÃrio de Ãnions. Os resultados indicaram que uma temperatura de 45 oC propicia melhor remoÃÃo do agrotÃxico usando apenas a radiaÃÃo UV, contudo, para o sistema combinado UV/H2O2, a temperatura nÃo afetou o rendimento do processo. A influÃncia do pH foi estudada para os sistemas H2O2 e UV/H2O2 e foi verificado que o pH nÃo influenciou na eficiÃncia do sistema UV/H2O2, entretanto, em pH 10 ocorreu um melhor rendimento para o sistema H2O2 na remoÃÃo do agrotÃxico. Entre as dosagens de perÃxido de hidrogÃnio estudadas, a de 1,5g/L foi a mais eficiente na remoÃÃo do agrotÃxico. O efeito inibitÃrio dos Ãnions, cloreto, nitrato, sulfato e carbonato nÃo se mostrou efetivo na remoÃÃo do agrotÃxico durante 480 minutos, contudo, o Ãnion bicarbonato provocou em 60 minutos a total conversÃo do clorpirifÃs em um composto desconhecido. A segunda etapa foi realizada no reator de escala piloto e foram estudados trÃs vazÃes, 1,5; 2,0 e 3,0 L/min. As concentraÃÃes residuais do agrotÃxico ao final de 480 minutos de experimento para os trÃs vazÃes foram 0,30; 0,43 e 0,5 mg/L, respectivamente. A remoÃÃo de turbidez e cor foram eficientes para as vazÃes estudadas, em contraste com a remoÃÃo de DQO.
This study investigated to advanced oxidation process (POA) for removal of organophosphorus pesticide chlorpyrifos. Reactor system, in laboratory and pilot scale, have been studied. In the first stage, in laboratory scale, were performed studies of the parameters temperature, pH, dosage of hydrogen peroxide, pesticide concentration and inhibitory effects of anions. The results indicated that a temperature of 45 oC showed a better pesticide removal using only UV radiation, however, for the system UV/H2O2, the temperature did not affect the process. The pH effect was studied for H2O2 and UV/H2O2 systems and was observed that pH did not affect the efficiency of the system UV/H2O2. In addition, at pH 10 a better performance for the system H2O2 on the removal of pesticide was observed. Hydrogen peroxide dosage also was studied, and 1,5g/L dosage was most efficient in the pesticide removal. The inhibitory effect of the anions, such as chloride, nitrate, sulfate and bicarbonate was not significantive in the pesticide removal at a time of 480 minutes. In contrast, presence of carbonate anion at 60 minutes, there was a total transformation of chlorpyrifos in an unknown compound. The second stage was conducted on a pilot scale, and flow rate were studied (1.5; 2.0 and 3.0 L/min). The final concentration of pesticide at 480 minutes, for the three flow, were 0.30; 0.43 and 0.5 mg/L, respectively. The turbidity and color removal was efficient for all flows studied, in contrast with the DQO removal.
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Voorhees, Jaymie Richelle. "Cognitive impairment and neuronal damage in Alzheimer's disease are malleable: occupational chlorpyrifos exposure exacerbates phenotypes, while the neuroprotective compound P7C3 ameliorates effects in a transgenic model of Alzheimer's disease." Diss., University of Iowa, 2017. https://ir.uiowa.edu/etd/5871.
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Alzheimer’s disease (AD) is a devastating neurodegenerative disease that affects millions of peoples’ lives worldwide. While the consequences of AD are recognizable, the etiology is unclear. Gene-environment interactions have been implicated in the development of the disease, and exposure to organophosphorus (OPs) compounds is one of the environmental factors associated with AD. Evidence links exposure to levels of OPs encountered in agriculture, horticulture, and other work places with neurodegenerative disease, psychiatric illness, and sensorimotor deficits. Unfortunately, the mechanisms underlying these effects have yet to be established. Here, we set out to examine the long-term consequences of exposure to a commonly applied OP insecticide, chlorpyrifos (CPF), in an attempt to identify a causal link between occupational exposures and chronic illnesses. We exposed a transgenic rodent model of AD, TgF344-AD, to levels of CPF representing occupational exposures and examined ensuing behaviors and neuropathologies. We observed a sex-specific, biphasic response in CPF-exposed animals, including acute neurotoxicities, followed by intermediate recovery, and finally, chronic cognitive impairments. CPF exposure exacerbated neuronal damage in brain regions critical to the impaired behaviors, and neuroinflammatory pathways were identified as facilitators of this damage. This work emphasizes the long-term consequences of early life repeated exposures to OPs and identifies dysregulated microglia as a potential deleterious modifier of disease.
Additionally, we investigated the efficacy of a neuroprotective compound, (-)-P7C3-S243 in TgF344-AD rats. P7C3 compounds exert protection by preventing young hippocampal neurons from dying prematurely and also enhancing flux of nicotinamide adenine dinucleotide (NAD), thereby aiding in neuron survival under conditions that normally cause axon degeneration and cell death. These compounds have proven effective in preclinical models of Parkinson’s disease, amyotrophic lateral sclerosis, and traumatic brain injury. Thus, we sought to investigate the neuroprotective efficacy of P7C3 compounds in AD, as well. (-)-P7C3-S243 was administered to wild-type and transgenic male and female rats daily for 9 and 18 months, and classic hallmarks of the disease were assessed. Transgenic rats developed a spectrum of AD pathologies and behaviors, as expected, and (-)-P7C3-S243 ameliorated early depression-like behaviors, late learning and memory deficits, and progressive neuronal damage in this model, without influencing amyloid plaque deposition, tauopathies, or neuroinflammation. This data suggests that targeting neuronal cell death pathways is a promising treatment strategy in AD.
Taken together, the research presented here expands our current understanding of pathways of regulation in Alzheimer’s disease—organophosphates are capable of exacerbating the severity of AD, while P7C3 compounds are promising therapeutic candidates for neuronal death in the disease. Given the overlapping molecular pathways of modulation in CPF-induced toxicity and (-)-P7C3-S243 neuroprotection in AD, future studies will investigate the efficacy of (-)-P7C3-S243 in cognitive deficits induced by CPF exposure. Ultimately, this body of work highlights the plasticity of neuronal cell death and cognitive impairment in AD, thus indicating a better understanding of these pathways could facilitate vastly improved intervention strategies in Alzheimer’s disease.
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Tripodi, Neil. "Environmental fate and effects of the non-persistent pesticide, Chlorpyrifos-methyl, and the implications for its risk assessment in aquatic ecosystems /." [St. Lucia, Qld.], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18685.pdf.
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Tofolo, Viviane Cristina. "Toxicidade de formicidas utilizados em pastagens sobre a formiga não-alvo Ectatomma brunneum (Hymenoptera, Formicidae, Ectatomminae) e seus efeitos na dinâmica populacional em condições de laboratório /." Rio Claro : [s.n.], 2007. http://hdl.handle.net/11449/99506.
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Resumo: O objetivo deste trabalho foi procurar conhecer os efeitos de três substâncias químicas, sulfluramida, fipronil e clorpirifós, sobre a espécie de formiga não-alvo Ectatomma brunneum (Hymenoptera: Formicidae: Ectatomminae), respondendo às seguintes questões: as marcas comerciais de iscas formicidas granuladas utilizadas neste trabalho são atrativas a esta espécie de formiga não-alvo ou simplesmente repelentes? Sendo atrativas, qual o comportamento exercido pelas operárias? Elas ingerem as iscas no local ou carregam para o interior do ninho? Há devolução? Em condições de múltipla escolha alimentar, esta atratividade permanece ou ocorre somente na ausência do alimento convencional? No que acarreta o contato direto e indireto das formigas com as iscas? Ocorre mortalidade significativa? Qual dos ingredientes ativos é mais prejudicial? Os produtos são seletivos? Os resultados obtidos através dos testes em laboratório revelaram que, em condições normais de exposição, as operárias de E. brunneum não foram repelidas pelas iscas formicidas. No entanto, não houve atratividade suficiente para induzir o carregamento ou ingestão. Quando esse material foi umedecido, a atratividade aumentou significativamente, permitindo que porções das iscas fossem ingeridas na própria arena de forrageamento ou carregadas para o interior do ninho e distribuídas aos outros indivíduos, não sendo registrada, em nenhum dos tratamentos, a devolução total ou parcial das porções carregadas. Após 48 horas de exposição, os três ingredientes ativos foram tóxicos, de modo que a população foi reduzida em 35,56% no tratamento com clorpirifós, 31,11% com sulfluramida e 30% com fipronil ao final de 20 dias de observação. As iscas à base de fipronil foram mais atrativas que as de sulfluramida e clorpirifós...(Resumo completo, clicar acesso eletrônico abaixo)Abstract: This work aimed at contributing to a better knowledge on the effects of three chemical substances, sulfluramid, fipronil and chlorpyrifos, on the non-target species of ant Ectatomma brunneum (Hymenoptera: Formicidae: Ectatomminae), answering the following questions: are the brands of granulated insecticide baits employed in this work attractive to this species of non-target ant or are they just repellent? If attractive, what is the behavior exhibited by the workers? Do they ingest the baits in the spot or take them into the nest? Is there any devolution? Under conditions of multiple food choice, does this attractiveness remain or does it happen only in the lack of the conventional food? What is the outcome of direct or indirect contact between the ants and the baits? Is there significant mortality? Which of the active ingredients is the most harmful? Are the products selective? The results obtained from the tests in laboratory showed that, under conditions of normal exposure, the workers of E. brunneum were not repelled by the insecticide baits. Nevertheless, there was not enough attractiveness as to lead to transporting or ingesting. When the material was moistened, the attractiveness increased significantly, allowing portions of bait to be ingested at the very foraging arena or to be taken into the nest and distributed to the other individuals. Total or partial devolution of the portions carried was not observed in any of the treatments. After a 48 hour exposure the three active ingredients proved to be toxic, for the population was reduced in 35.56% in the treatment with chlorpyrifos, 31.11% with sulfluramid and 30% with fipronil at the end of 20 days of observation. The fipronil based baits were more attractive than the ones based on sulfluramid and chlorpyrifos...(Complete abstract click electronic access below)
Orientador: Edilberto Giannotti
Coorientador: Marcos Aparecido Pizano
Banca: Evoneo Berti Filho
Banca: Nivar Gobbi
Mestre
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Heckmann, Jonathan Gardner. "Effects of atrazine, chlorpyrifos, and their interactions on anti-predator behavior and activity in African clawed frogs, Xenopus laevis." Thesis, Wichita State University, 2009. http://hdl.handle.net/10057/2428.
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Two separate experiments were conducted to examine potential mixture effects of chronic, sub-lethal concentrations of atrazine and chlorpyrifos on the alarm response and activity of larva of the African clawed frog, Xenopus Laevis. Larvae were exposed to three concentrations of atrazine, (0, 20, and 200 μg/L), three concentrations of chlorpyrifos (0, 1, and 10 μg/L), and all possible combinations of those doses for a period of two weeks prior to behavioral testing.
Activity of larvae was evaluated by measuring both how many seconds the larvae spent active in any way and also by measuring the number of times the larvae crossed the center line of their experimental container. Alarm responses were provoked by introduction of an “alarm substance,” to which larvae reacted by exhibiting anti-predator behavior. This alarm response was evaluated by measuring the amount of time spent active before and after alarm substance introduction (depressed activity is the typical alarm response), as well as the amount of time spent opposite the end of the experimental container where the alarm substance was introduced. Behavioral trials were videotaped for purposes of data collection.Thesis (M.S.)--Wichita State University, College of Liberal Arts and Sciences, Dept. of Biological Sciences
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Fernandes, Garcia Néio Lúcio [UNESP]. "Influência do pH do diluidor, na ação de caldas ixodicidas (amitraz, clorpirifós e cipermetrina), contra Rhipicephalus (Boophilus) microplus (Canestrini, 1887) (acarina: ixodidae)." Universidade Estadual Paulista (UNESP), 2007. http://hdl.handle.net/11449/94652.
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O presente trabalho procurou verificar a possível interferência do pH do diluidor na eficiência de ixodicidas comerciais. Para tanto, utilizou-se amitraz, clorpirifós, cipermetrina, mais um grupo controle, para verificar os possíveis efeitos de soluções tampão com pH 3, 4, 5, 6, 7, 8, 9, 10 e 11, como diluidores dos ixodicidas, sobre as variáveis: peso médio da oviposição (PMO), relação PMOxPT (peso das teleóginas), porcentagem de eclosão (PE), eficiência reprodutiva (ER) e eficácia da calda (EC). Teleóginas de R. (B.) microplus, obtidas de bovinos infestados com cepa de campo, foram submetidas à biocarrapaticidogramas, uma hora e 24 horas após preparo (HAP) das caldas. O pH do diluente pouco influenciou na eficácia do amitraz nos parâmetros avaliados, embora as linhas de tendência dos resultados para ER e EC tenham mostrado menor ação do ixodicida, à medida que o pH do diluidor aumentava, tanto para uma HAP como para 24 HAP. Para o clorpirifós, os resultados obtidos mostraram diferenças significativas no PMO, PMOxPT e PE nos resultados de uma hora. A ER (uma HAP) e EC (24 HAP) foram influenciadas negativamente pelo pH quando este se elevava. As linhas de tendência dos resultados para ER e EC mostraram diminuição da ação à medida que o pH do diluidor aumentava, tanto para uma hora como para 24 horas. A cipermetrina sofreu pouca influência do pH. Entretanto, a linha de tendência dos resultados para EC foi influenciada pela elevação do pH, quando usada 24 HAP.
The objective of the present research is to check, with commercial ixodicides, the possible interference of the pH of the thinner. For this amitraz, chlorpyrifos, cypermethrin, plus a control group, was used to verify the possible effects of buffer solutions with pH 3, 4, 5, 6, 7, 8, 9, 10 and 11, as thinners of the ixodicides, on the following: medium weight of egg mass (PMO), relationship PMOxPT (weight of the teleogines), percentage of larvae hatch (PE), estimated reproduction (ER) and % control (EC). Teleogines of R. (B.) microplus, obtained from cattle infested with field's strains have been submitted to the in vitro immersion tests, one hour and 24 hours after the solution has been prepared (HAP). The pH of the thinners made little difference on the amitraz on the parameters assessed and, statistically, did not show any significant differences, although the tendency of the results for ER and EC showed less action of ixodicide, as the pH of the thinner increased, as much for one HAP as for 24 HAP. As for chlorpyrifos, the results obtained, statistically showed significant differences on the PMO, PMOxPT and PE in the results of one hour. The ER (one HAP) and EC (24 HAP), were negatively affected by pH when this was augmented. The tendency of the results for ER and EC showed a diminution from the action, as the pH from the thinner augmented, as much for one HAP as for 24 HAP. The cypermetrin suffered less influence from pH. However, the tendency of the results for EC were affected by the elevation of pH, when used 24 HAP.
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Yorulmaz, Sibel Ay Recep. "Tetranychus urticae (Acarina: teranychidae)'nin üç farklı insektisit-akarisit ile seleksiyonundan sonra çoklu direnç ve bazı enzim düzeylerinin incelenmesi /." Isparta : SDÜ Fen Bilimleri Enstitüsü, 2008. http://tez.sdu.edu.tr/Tezler/TF01124.pdf.
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Souza, Tamara Daiane de. "Remoção do inseticida clorpirifós em sistemas alagados construídos cultivados com diferentes espécies vegetais." Universidade Federal de Viçosa, 2013. http://locus.ufv.br/handle/123456789/3640.
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Previous issue date: 2013-03-15Conselho Nacional de Desenvolvimento Científico e Tecnológico
Over the last decades, it has been found high levels of water contamination with substances derived from agricultural areas. In this context, we highlight the organophosphate insecticides, which offer high risk to public drinking, watering livestock and preservation of aquatic flora and fauna. Chlorpyrifos, included in this class, is a widely used insecticide in the world and is among the most used in Brazil. Given the damage caused by these substances when they reach water bodies, plus the difficulty of remediation of these environments, it is essential to know techniques to minimize this process. The constructed wetlands (CWs) are shown as an alternative, and some experiments have demonstrated their ability to remove recalcitrant contaminants such as pesticides. The objective of this research was to evaluate the ability of remediation of water contaminated with the insecticide chlorpyrifos through horizontal subsurface flow constructed wetlands planted with different macrophytes. It was measured the reduction of the chlorpyrifos concentration and the reduction of toxicity over hydraulic retention times of 24, 48, 96, 144 and 192 h. The experiment consisted in four pilot scale CWs: CWC without vegetation; CWT cultivated with Tifton 85 (Cynodon spp.); CWM cultivated with Mentha aquatic and CWE cultivated with dotted knotweed (Polygonum punctatum). The initial concentration of chlorpyrifos applied in all CWs was 1 mg.L-1. Before beginning the treatments, it was applied diluted sewage for biofilm insertion on the systems. For execution of quality ecotoxicological acute tests, it was used the specie Daphnia similis. The analysis of variance showed there was no statistical difference, at the 5% level of probability, in the removal of chlorpyrifos between the studied CWs and over the hydraulic retention times. There was a great efficiency in removing pesticide, with overall average of 98.6%, whereas in the first hydraulic retention time, 24 h, there was removal of chlorpyrifos to below the limit of detection, implying at efficiency greater than 99% for the CWC, CWM, CWE and CWT. This result is mainly attributed to adsorption and microbial degradation. For standard acute toxicity tests with Daphnia similis, in accordance with results from removal efficiency of chlorpyrifos, for most samples there was a reduction in toxicity above 80%. Ecotoxicological tests with effluents of constructed wetland systems studied are a good choice as an indicator of the effectiveness of treatments and a promising alternative to complement the physical and chemical analyzes.
Nas últimas décadas, tem-se constatado alto índice de contaminação dos recursos hídricos com substâncias oriundas de áreas agrícolas. Neste contexto, destacam-se os inseticidas organofosforados, que oferecem elevado risco para abastecimento público, dessedentação de animais e preservação da flora e fauna aquática. O clorpirifós, incluído nesta classe, é um inseticida amplamente utilizado no mundo e está entre os mais utilizados no Brasil. Face aos danos causados por estas substâncias quando alcançam corpos hídricos, somado à dificuldade de remediação destes ambientes, torna-se essencial o conhecimento de técnicas capazes de minimizar tal processo. Os Sistemas Alagados Construídos (SACs) mostram-se como uma alternativa, tendo sido evidenciado em alguns experimentos sua capacidade de remover contaminantes recalcitrantes, como os pesticidas. O objetivo desta pesquisa foi avaliar a capacidade de remediação de água contaminada com o inseticida clorpirifós, por meio de sistemas alagados construídos de escoamento horizontal subsuperficial, em que foram cultivados diferentes macrófitas. Mensurou-se a redução da concentração do clorpirifós bem como a redução da toxicidade nos tempos de retenção hidráulica de 24, 48, 96, 144 e 192 h. O experimento foi composto por quatro SACs construídos em escala piloto: SACC sem vegetação; SACT cultivado com capim tifton 85 (Cynodon spp.); SACM cultivado com Mentha aquatica e SACE cultivado com Erva de bicho (Polygonum punctatum). A concentração inicial de clorpirifós aplicada em todos os SACs foi de 1 mg L-1. Antes do início dos tratamentos, aplicou-se esgoto sanitário diluído para inserção do biofilme no sistema. Para realização do teste ecotoxicológico agudo qualitativo, utilizou-se a espécie Daphnia similis. A análise de variância demonstrou que não houve diferença estatística significativa, em nível de 5% de probabilidade, na remoção do clorpirifós entre os SACs estudados e ao longo dos tempos de retenção hidráulica. Observou-se pelas análises cromatográficas alta eficiência na remoção do inseticida, com média geral de 98,6%, sendo que já no primeiro tempo de retenção hidráulica, 24 h, houve remoção do clorpirifós para valores inferiores ao limite detecção do CG, implicando em uma eficiência maior que 99% para os sistemas SACc, SACM, SACE e SACT. Tal resultado é atribuído principalmente aos processos de adsorção e degradação microbiana. Para os ensaios padronizados qualitativos de toxicidade aguda com Daphnia similis, de forma semelhante aos resultados de eficiência de remoção do clorpirifós, observou-se para a maioria das amostras a redução de toxicidade acima de 80%. Constatou-se que os testes ecotoxicológicos com os efluentes dos sistemas alagados construídos estudados são uma boa opção como indicativo da eficiência dos tratamentos e uma promissora alternativa na complementação de análises físicas e químicas.
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Phung, Dung Tri. "Assessing and Reducing Risk Due to Chlorpyrifos Use among Rice Farmers in Vietnam: From Probabilistic Risk Assessment to Safety Strategy Development." Thesis, Griffith University, 2012. http://hdl.handle.net/10072/365804.
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Vietnamese farmers are at high risk of pesticide exposure due to usage of pack-back sprays for application of pesticides with their rice crops. Chlorpyirifos has been the most common organophosphate registered for agricultural use in Vietnam, however the health risk due to the use of this compound by rice farmers has not been evaluated. The primary objective of this study was to evaluate the health risk of chlorpyrifos exposure to rice farmers, using a probabilistic approach, with a secondary objective of developing safety strategies for pesticide risk reduction, using qualitative needs assessment methods used for evaluating health promotion programs. Farmer exposure to chlorpyrifos from pesticide application was measured by biological monitoring. Urine samples were collected from farmers (18) over pesticide spraying application time and analysed for 3,5,6-trichloropyridinol (TCP), the major urinary metabolite of chlorpyrifos, using an enzymatic pre-treatment before extraction followed by high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). Absorbed Daily Doses (ADD) of chlorpyrifos for farmers was then estimated from urinary TCP levels, expressed as μg/g creatinine. The exposure doses, comprising baseline exposure dose (ADDB), post-application exposure dose (ADDA), and lifetime average daily exposure dose (LADDE) were calculated. The baseline exposure dose (ADDB) ranged from 0.03 to 1.98 μg/kg/d with a mean of 0.24 μg/kg/d. The post-application exposure dose (ADDA) ranged from 0.35 to 94 μg/kg/d with a mean of 19.4 μg/kg/d which is approximately 80 times higher than the mean values of ADDB (0.24 μg/kg/d). The lifetime average daily dose (LADDE) ranged from 0.01 to 1.7 μg/kg/d with a mean of 0.3 μg/kg/d. Multivariate regression analysis indicated that personal protective equipment reflected by percentage of body coverage, amount of chlorpyrifos used and length of application made major contributions to ADDA. However, the best regression model for the relationship between ADDA and exposure factors was observed with two independent variables comprising body coverage and amount of chlorpyrifos used.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Environment
Science, Environment, Engineering and Technology
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Fernandes, Lilian Caroline. "Avaliação comportamental frente a exposição crônica de baixas doses de Paraquat e associações em ratos Wistar machos." Universidade Estadual de Ponta Grossa, 2018. http://tede2.uepg.br/jspui/handle/prefix/2596.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico
O aumento progressivo da população e da produção de alimentos torna o uso de agrotóxicos essencial. O Brasil tem notoriedade à nível mundial na quantidade desses produtos comercializados, sendo destaque desde 2008. As classes mais utilizadas são os herbicidas, fungicidas e inseticidas. Sabe-se que esses produtos apresentam risco a saúde humana, podendo afetar múltiplos sistemas. Além disso, alguns estudos estão demonstrando efeitos neurotóxicos e comportamentais causados por esses agentes, no entanto, o mecanismo desse efeito permanece incerto. Os pesticidas têm diferentes mecanismos de ação e ainda, podem apresentar efeitos sinérgicos entre si. Com isso, o presente estudo busca avaliar se a exposição ao Paraquat, que é um herbicida, amplamente utilizado devido ao seu baixo curso e amplo espectro de forma isolada e as associações com Mancozeb, que é um fungicida e com o Clorpirifós, que é um inseticida são capazes de produzir efeitos comportamentais. Para isso, foram utilizados 48 ratos machos da linhagem Wistar divididos em 4 grupos de acordo com o agente de exposição: Controle/Água (N=12), Paraquat 1mg/kg (N=12), Paraquat 1mg/kg e Mancozeb 3 mg/kg (N=12), Paraquat 1mg/kg e Clorpirifós 0,3 mg/kg (N=12). A exposição ocorreu diariamente durante 28 dias por via oral (gavagem). Após o período de exposição, foram realizados os testes de preferência à sacarose, reconhecimento social, campo aberto, reconhecimento de objetos, labirinto em cruz elevado e natação forçada. Como resultado têm-se que os animais submetidos ao tratamento apresentaram déficit na memória social e declarativa, evidenciado pelo teste de reconhecimento social e de objetos. Além disso, apresentaram também sinais do tipo ansiogênicos e depressivos demonstrado pelo teste de labirinto em cruz elevado e natação forçada. Além dos sinais não motores os animais também apresentaram comprometimento motor, evidenciado pelo teste de campo aberto. Como conclusão, demonstramos que a exposição ao Paraquat e associações com Mancozeb e Clorpirifós causou alterações comportamentais nos animais submetidos a exposição com Paraquat e associação com Mancozeb e Clorpirifós.
The progressive increase in population and food production makes the use of agrochemicals essential. Brazil is known worldwide in the quantity of these products marketed, being highlighted since 2008. The classes most used are herbicides, fungicides and insecticides. It is known that these products pose a risk to human health and can affect multiple systems. In addition, some studies are demonstrating neurotoxic and behavioral effects caused by these agents, however, the mechanism of this effect remains uncertain. Thus, the present study aims to evaluate whether exposure to Paraquat, which is a herbicide, widely used because of its low cost and broad spectrum in isolation and as associations with Mancozeb, which is a fungicide and with Chlorpyrifos, which is an insecticide are capable of producing effects. For this, 48 male Wistar rats divided into 4 groups according to the exposure agent: Control/Water (N= 12), Paraquat 1mg/kg (N=12), Paraquat 1mg/kg and Mancozeb 3 mg/kg (N = 12), Paraquat 1 mg/kg and Chlorpyrifos 0.3 mg/kg (N = 12). The exposure occurred daily for 28 days orally (gavage). After the exposure period, sucrose preference tests, social recognition, open field, object recognition, elevated plus maze and forced swimming were performed. As a result, the animals submitted to the treatment had deficits in the social and declarative memory, evidenced by the test of social recognition and objects. In addition, they also presented anxiogenic and depressive signs, demonstrated by the elevated plus maze test and forced swimming. In addition to non-motor signals, the animals also presented motor impairment, evidenced by the open field test. As a conclusion, we demonstrated that exposure to Paraquat and associations with Mancozeb and Chlorpyrifos caused behavioral changes in animals submitted to Paraquat exposure and associated with Mancozeb and Chlorpyrifos.
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Adam, Hassan Ali. "A solid phase microextraction/gas chromatography method for estimating the concentrations of chlorpyrifos, endosulphan-alpha, edosulphan-beta and endosulphan sulphate in water." Thesis, Peninsula Technikon, 2003. http://hdl.handle.net/20.500.11838/899.
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Thesis (MTech (Chemical Engineering))--Peninsula Technikon, Cape Town, 2003The monitoring of pesticide contamination in surface and groundwater is an essential aspect of an assessment of the potential environmental and health impacts of widespread pesticide use. Previous research in three Western Cape farming areas found consistent (37% to 69% of samples) pesticide contamination of rural water sources. However, despite the need, monitoring of pesticides in water is not done due to lack of analytical capacity and the cost of analysis in South Africa. The Solid Phase Microextraction (SPME) sampling method has been developed over the last decade as a replacement for solvent-based analyte extraction procedures. The method utilizes a short, thin, solid rod of fused silica coated with an absorbent polymer. The fibre is exposed to the pesticide contaminated water sample under vigorous agitation. The pesticide is absorbed into the polymer coating; the mass absorbed depends on the partition coefficient of the pesticide between the sample phase and the polymeric coating, the exposure time and factors such as agitation rate, the diffusivity of the analyte in water and the polymeric coating, and the volume and thickness of the coating. After absorption, the fibre is directly inserted into the Gas Chromatograph (GC) injection port for analysis. For extraction from a stirred solution a fibre will have a boundary region where the solution moves slowly near the fibre surface and faster further away until the analyte is practically perfectly mixed in the bulk solution by convection. The boundary region may be modelled as a layer of stationary solution surrounded by perfectly mixed solution.
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Guardia, Escoté Laia. "Postnatal chlorpyrifos exposure influences the gut microbiota and the expression of biological and neurobehavioral characteristics of the APOE genotype in an age-dependent manner." Doctoral thesis, Universitat Rovira i Virgili, 2019. http://hdl.handle.net/10803/668443.
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Certs determinants genètics com els polimorfismes de l’apolipoproteïna E (APOE) poden influir la resposta a factors ambientals. Les variants humanes més freqüents de l’APOE confereixen diferent vulnerabilitat a tòxics, en particular al pesticida clorpirifós (CPF). Un ús massiu de plaguicides pot desencadenar efectes perjudicials en la població, que presenta una major vulnerabilitat durant el desenvolupament. En aquest estudi es va avaluar la contribució del genotip APOE sobre els efectes conductuals i bioquímics produïts per l’exposició a CPF a diferents etapes. Els ratolins apoE3-, apoE4-TR i C57BL/6 van ser exposats a 0 o 1 mg/kg/dia de CPF del dia postnatal 10 al 15. Es va estudiar la microbiota intestinal i els àcids grassos de cadena curta al cervell en nounats i la memòria de reconeixement en joves. La memòria espacial i l’expressió d’elements del sistema colinèrgic es van avaluar en adults. Al llarg de l'estudi es van observar diferències del genotip APOE, modulant la resposta a CPF. ApoE4-TR va presentar diferències en la microbiota i major susceptibilitat a la disbiosi induïda per CPF. El genotip APOE3 i els ratolins exposats a CPF presentaven nivells més elevats d’àcids grassos de cadena curta. Els ratolins apoE3-TR adults no van assolir la tasca i l’exposició a CPF va empitjorar la memòria de reconeixement. L’estudi farmacològic va revelar diferències en el sistema colinèrgic i GABAèrgic. Els ratolins apoE4 presentaven pitjor memòria espacial i diferències en l’expressió d’elements colinèrgics al cervell. L’exposició a CPF va provocar efectes depenent del sexe en la memòria espacial, i canvis en l’expressió d’elements colinèrgics. En general, aquest estudi demostra que l’exposició postnatal a CPF provoca efectes a llarg termini. Les característiques del genotip APOE atorguen diferent vulnerabilitat als efectes de CPF depenent del sexe, donant així una visió més detallada de les interaccions gen-ambient a diferents etapes de la vida.Ciertos determinantes genéticos como los polimorfismos de la apolipoproteína E (APOE) pueden influenciar la respuesta a factores ambientales. Las variantes humanas más frecuentes de APOE confieren diferente vulnerabilidad a tóxicos, en particular al pesticida clorpirifós (CPF). Un uso masivo puede provocar efectos perjudiciales en la población, que presenta una mayor vulnerabilidad durante el desarrollo. En este estudio se determinó la contribución del genotipo APOE sobre los efectos conductuales y bioquímicos producidos por la exposición a CPF en tres etapas. Los ratones apoE3-, apoE4-TR y C57BL/6 fueron expuestos a 0 o 1 mg/kg/día de CPF del día postnatal 10 al 15. Se estudió la microbiota intestinal y los ácidos grasos de cadena corta en cerebro en neonatos y la memoria de reconocimiento en jóvenes. Se evaluó la memoria espacial y la expresión de elementos del sistema colinérgico en adultos. A lo largo del estudio se observaron diferencias del genotipo APOE, modulando la respuesta a CPF. ApoE4-TR presentó diferencias en la microbiota y mayor susceptibilidad a la disbiosis inducida por CPF. El genotipo APOE3 y los ratones expuestos presentaron niveles más elevados de ácidos grasos de cadena corta. Los ratones apoE3-TR adultos no adquirieron la tarea y la exposición a CPF empeoró la memoria de reconocimiento. El estudio farmacológico reveló diferencias en el sistema colinérgico y GABAérgico. Los ratones apoE4 presentaron peor memoria espacial y diferencias en la expresión de elementos colinérgicos en el cerebro. La exposición a CPF provocó efectos dependiendo del sexo en la memoria espacial, y cambios en la expresión de elementos colinérgicos. En general, este estudio demuestra que la exposición postnatal a CPF provoca efectos a largo plazo. Las características del genotipo APOE otorgan diferente vulnerabilidad a los efectos de CPF dependiendo del sexo, dando así una visión más detallada de las interacciones gen-ambiente durante la vida.
Genetic determinants such as the polymorphism of the apolipoprotein E (APOE) gene can influence the response to environmental factors. The most frequent human APOE genetic variants confer different vulnerabilities to toxics, in particular to the worldwide used pesticide chlorpyrifos (CPF). A massive use of pesticides can trigger detrimental effects in general population, who present higher vulnerability during development. In the present study we assessed the APOE genotype contribution on behavioral and biochemical effects after postnatal exposure to CPF at different times during lifespan. ApoE3-, apoE4-TR and C57BL/6 mice were exposed to 0 or 1 mg/kg/day of CPF from postnatal day 10 to 15. Gut microbiota composition and cerebral short-chain fatty acids (SCFAs) levels were studied at early ages whereas recognition memory was assessed in young adults. Spatial learning and memory and gene expression of cholinergic elements were evaluated in middle-aged mice. Differences between APOE genotypes were observed throughout the study, modulating the response to CPF. First, apoE4-TR presented differences in the core microbial communities and was the most affected by CPF-induced dysbiosis. Besides, apoE3-TR and CPF-treated mice presented higher levels of SCFAs. Adult apoE3-TR mice failed to recognize the novel object whereas CPF impaired recognition memory. The pharmacological challenge revealed differences in cholinergic and GABAergic systems between groups. ApoE4 presented worse spatial memory compared to C57BL/6, which was modulated by CPF exposure in a sex-dependent manner, and altered expression of cholinergic elements in the brain, being also influenced by postnatal CPF exposure. Overall, the current results show that postnatal exposure to CPF produce long-lasting effects in adults. The different characteristics conferred by the APOE genotype grant different levels of vulnerability to CPF-elicited effects in a sex-dependent manner, thereby giving further insight on gene-environment interactions at different points during lifetime.
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Tofolo, Viviane Cristina [UNESP]. "Toxicidade de formicidas utilizados em pastagens sobre a formiga não-alvo Ectatomma brunneum (Hymenoptera, Formicidae, Ectatomminae) e seus efeitos na dinâmica populacional em condições de laboratório." Universidade Estadual Paulista (UNESP), 2007. http://hdl.handle.net/11449/99506.
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O objetivo deste trabalho foi procurar conhecer os efeitos de três substâncias químicas, sulfluramida, fipronil e clorpirifós, sobre a espécie de formiga não-alvo Ectatomma brunneum (Hymenoptera: Formicidae: Ectatomminae), respondendo às seguintes questões: as marcas comerciais de iscas formicidas granuladas utilizadas neste trabalho são atrativas a esta espécie de formiga não-alvo ou simplesmente repelentes? Sendo atrativas, qual o comportamento exercido pelas operárias? Elas ingerem as iscas no local ou carregam para o interior do ninho? Há devolução? Em condições de múltipla escolha alimentar, esta atratividade permanece ou ocorre somente na ausência do alimento convencional? No que acarreta o contato direto e indireto das formigas com as iscas? Ocorre mortalidade significativa? Qual dos ingredientes ativos é mais prejudicial? Os produtos são seletivos? Os resultados obtidos através dos testes em laboratório revelaram que, em condições normais de exposição, as operárias de E. brunneum não foram repelidas pelas iscas formicidas. No entanto, não houve atratividade suficiente para induzir o carregamento ou ingestão. Quando esse material foi umedecido, a atratividade aumentou significativamente, permitindo que porções das iscas fossem ingeridas na própria arena de forrageamento ou carregadas para o interior do ninho e distribuídas aos outros indivíduos, não sendo registrada, em nenhum dos tratamentos, a devolução total ou parcial das porções carregadas. Após 48 horas de exposição, os três ingredientes ativos foram tóxicos, de modo que a população foi reduzida em 35,56% no tratamento com clorpirifós, 31,11% com sulfluramida e 30% com fipronil ao final de 20 dias de observação. As iscas à base de fipronil foram mais atrativas que as de sulfluramida e clorpirifós...
This work aimed at contributing to a better knowledge on the effects of three chemical substances, sulfluramid, fipronil and chlorpyrifos, on the non-target species of ant Ectatomma brunneum (Hymenoptera: Formicidae: Ectatomminae), answering the following questions: are the brands of granulated insecticide baits employed in this work attractive to this species of non-target ant or are they just repellent? If attractive, what is the behavior exhibited by the workers? Do they ingest the baits in the spot or take them into the nest? Is there any devolution? Under conditions of multiple food choice, does this attractiveness remain or does it happen only in the lack of the conventional food? What is the outcome of direct or indirect contact between the ants and the baits? Is there significant mortality? Which of the active ingredients is the most harmful? Are the products selective? The results obtained from the tests in laboratory showed that, under conditions of normal exposure, the workers of E. brunneum were not repelled by the insecticide baits. Nevertheless, there was not enough attractiveness as to lead to transporting or ingesting. When the material was moistened, the attractiveness increased significantly, allowing portions of bait to be ingested at the very foraging arena or to be taken into the nest and distributed to the other individuals. Total or partial devolution of the portions carried was not observed in any of the treatments. After a 48 hour exposure the three active ingredients proved to be toxic, for the population was reduced in 35.56% in the treatment with chlorpyrifos, 31.11% with sulfluramid and 30% with fipronil at the end of 20 days of observation. The fipronil based baits were more attractive than the ones based on sulfluramid and chlorpyrifos...(Complete abstract click electronic access below)
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Lewis, Mary Catherine. "The Effect of Organophosphate Exposure on Neocortical, Hippocampal and Striatal Monoamines: A Potential Substrate for Chronic Psychiatric, Cognitive and Motor Dysfunction." Thesis, Virginia Tech, 2003. http://hdl.handle.net/10919/34680.
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Depression and other mood disorders, as well as cognitive and motor dysfunction have been linked with changes in monoamine levels in the brain. Environmental acetylcholinesterase (AChE) inhibitors, such as organophosphate insecticides (OPs), have also been shown to induce these problems. This study investigated whether insecticide-induced AChE inhibition, induced by chlorpyrifos (CPS), may contribute to the types of forebrain monoaminergic alterations associated with psychiatric, cognitive and motor dysfunction. Increased synaptic ACh, resulting from CPS-induced AChE inhibition, may alter the synthesis or release of monoamines through prolonged action of ACh on monoaminergic neurons that contain ACh receptors. Adult, male Sprague-Dawley rats were subjected to a single subcutaneous dose of CPS or corn oil vehicle. Brains were rapidly removed and the frontal cortex, hippocampus and striatum were bilaterally dissected on ice. These three regions from one side were assayed for AChE activity, while those from the opposite side were processed for high performance liquid chromatography with electrochemical detection (HPLC-ED) analysis of monoamine neurotransmitters and their metabolites. In the initial, exploratory experiment, inhibition of AChE activity was 66.8% in the frontal cortex, 43.8% in the hippocampus and 46.9% in the striatum, 7 days after a 60mg/kg dose of CPS. No significant differences in concentration of monoamine neurochemicals were observed between vehicle control and CPS-treated groups in either the hippocampus or striatum. However, in the frontal cortex of the CPS-treated rats there was a significant increase in median dihydroxyphenylacetic acid (DOPAC) concentration (P=0.019) and a very strong statistical trend toward increased dopamine (DA) concentration (P=0.0506). The second experiment examined the time course of AChE inhibition produced by a higher dose (200mg/kg) of CPS and how monoamine levels changed in conjunction with this pattern of AChE inhibition. Percent inhibition of AChE activity in CPS-treated animals, at 4, 14 and 21 days post-exposure was 77.0%, 86.6% and 81.9% in the frontal cortex, 86.1%, 85.9% and 83.2% in the hippocampus and 90.1%, 89.8% and 85.5% in the striatum. No significant differences in monoamine neurochemicals were observed between vehicle control and CPS-treated groups in either the hippocampus or striatum. A statistical trend toward a decrease in serotonin (5-HT) was seen in the frontal cortex at 14 days (P=0.0753) following CPS exposure. A very consistent, yet non-significant pattern of an increase in monoamines at 4 days post-CPS was observed in all instances, except for 5-hydroxyindoleacetic acid (5-HIAA) in the striatum. Therefore, the final experiment employed a more powerful design to focus on monoamine levels during, or shortly after, the change in AChE activity that rapidly follows exposure to 200mg/kg CPS. This experiment also employed a behavioral analysis on the day of sacrifice to assess the presence or absence of clinical signs of toxicity associated with this dose. Of the 30 CPS-treated rats, only 1 animal displayed a single behavioral sign of cholinergic poisoning. Percent inhibition of AChE activity at 2 and 4 days after treatment was 81.4% and 79.4% in the frontal cortex, 53.4% and 83.5% in the hippocampus, and 80.5% and 87.8% in the striatum. No significant changes in monoamine neurochemicals were observed between vehicle control and CPS-treated groups in either the frontal cortex or hippocampus. However, a significant increase in DOPAC (P=0.0285) in the striatum, 2 days after CPS treatment, was observed. In addition, a strong statistical trend toward decreased striatal 5-HT (P=0.0645) was reported 4 days after CPS treatment. The only significant correlation between AChE activity and monoamine concentration was observed for 5-HIAA in the striatum of CPS-treated, 2 day survivors (P=0.0445). However, it was of low magnitude (r=0.525, r2=0.276). CPS has a limited capacity to produce changes in monoamine neurotransmitters and/or their metabolites in the frontal cortex and striatum of the mammalian brain. These changes are primarily seen in the dopaminergic system. Alterations of monoamines do not appear to be strongly associated with incident levels of AChE inhibition. The biological implication of the limited OP induced changes in central monoamines remains significant, as changes in monoamines in the CNS nervous system have been linked to psychiatric, cognitive and motor dysfunction.Master of Science
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Graça, Cátia Alexandra Leça. "Degradation of persistent pesticides via advanced oxidation and reductive processes." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/3/3137/tde-03082017-091224/.
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In this Thesis either advanced oxidation or reductive processes are investigated for the degradation of two pesticides considered persistent in the environment: amicarbazone (AMZ) and chlorpyrifos (CP). In chapter I, different advanced oxidation processes (AOPs) driven by sulfate (SO4o-) and hydroxyl radicals (oOH) were applied to the degradation of AMZ. In the first study, several persulfate (PS) activated reactions were explored for AMZ degradation, namely activation with UVA radiation, Fe(II) and H2O2, as well as the combination of UVA radiation with Fe(II), Fe(III) and Fe(III)-complexes. Here, the influence of different reaction variables, such as solution pH, reactants and pesticide initial concentrations, addition of a second oxidant (H2O2) and the addition of different iron catalysts were also investigated. Control experiments regarding the photolysis of iron species in the absence of PS captured our interest and, with the aim of exploring more deeply this process on AMZ degradation, a second investigation was carried out. In this second study, a Doehlert experimental design was applied to investigate the simultaneous effects of two variables on AMZ degradation: pH and Fe(III):carboxylate ratio, where the carboxylate could be oxalate, citrate or tartrate. A response surface model for the observed degradation rate (kobs) as a function of pH and Fe(III):carboxylate ratio was obtained. The processes explored in both aforementioned studies revealed to be effective for AMZ removal, although nothing is known yet about their effectiveness regarding toxicity removal. Given that, a third study was carried out, where the toxicity of AMZ solutions, before and after submission to the processes studied was evaluated towards five microorganisms: Vibrio fischeri (acute toxicity), Tetrahymena thermophile, Chlorella vulgaris (chronic toxicity), Escherichia coli and Bacilus subtilis (antimicrobial activity). The last investigation detailed in chapter I is related with the application of zero-valent-metals on PS activation, which is a subject that links this chapter with the following one. For that, zero-valent-iron (ZVI) was investigated as a PS activator and the influence of variables that help to assess the environmental applicability of this process. In general, organochlorine pesticides reveal a higher resistance to oxidation than reduction, the latter process preferred when the aim is to degrade that important class of contaminants. Therefore, in chapter II the reductive degradation of CP by means of zero-valent-metals and bimetallic particles was investigated. ZVI has been extensively applied for that purpose. However, besides iron, other zero-valent metals can be potential reactive materials for reductive degradation and hence, in this study, the effectiveness of Zn0 and Cu0 was also explored in comparison to that widely reported for ZVI. Furthermore, two different ways of enhancing metals reactivity were here explored: i) by coating ZVI or Zn0 with a more noble metal (Cu), in order to analyze the copper catalytic effect on the bimetallic system; ii) by different surface pretreatments.Na presente Tese de Doutorado foram abordados tanto processos oxidativos avançados (POA), como processos redutivos por metais de valência zero, na degradação de dois pesticidas considerados persistentes no meio ambiente: amicarbazona (AMZ) e clorpirifós (CP). No capítulo I são apresentados os estudos realizados com diversos POA, mediados por radicais sulfato (SO4o-) e hidroxila (oOH), aplicados da AMZ. Num primeiro estudo foi explorada a ativação do oxidante persulfato (PS), de diferentes formas, tais como radiação UVA, H2O2 e Fe(II), assim como a combinação de radiação UVA com Fe(II), Fe(III) e complexos de Fe(III). Aqui também foram investigados os efeitos de diversas variáveis reacionais, tais como pH, concentração inicial de reagentes e de pesticida, adição de um segundo oxidante (H2O2) e adição de diferentes espécies de ferro. Os testes realizados, para efeito de controle, referentes à irradiação das espécies de Fe(III) na ausência de PS, despertaram o interesse para um estudo mais aprofundado sobre o efeito da fotólise destas espécies na degradação da AMZ, surgindo assim o segundo trabalho. Neste utilizou-se um projeto experimental de Doehlert, para avaliar o efeito de duas variáveis em simultâneo quanto à degradação da AMZ: pH e proporção Fe(III): ligante, sendo o ligante um dos seguintes carboxilatos: oxalato, citrato ou tartarato. Um modelo de superfície de resposta, que correlaciona a taxa de degradação observada (kobs) em função do pH e proporção Fe(III):ligante foi obtido para cada um dos complexos de Fe(III) estudados. Os processos explorados, tanto no primeiro como no segundo estudo, se mostraram eficazes na remoção da AMZ, porém nada se sabe acerca da remoção da toxicidade. Para tal, foi desenvolvido um terceiro estudo dedicado à avaliação da toxicidade da solução de AMZ, antes e após a aplicação de cada um dos processos anteriormente abordados, contra cinco micro-organismos: Vibrio fischeri (toxicidade aguda); Tetrahymena thermophila, Chlorella vulgaris (toxicidade crônica); Escherichia coli e Bacilus subtilis (atividade antimicrobiana). O último estudo abordado no capitulo I é referente à aplicação de metais de valência zero também nos POA, correlacionado assim o capítulo I e o capítulo II. Como tal, foi feito um estudo de ativação de PS por meio de ferro de valência zero (Fe0), em que se investigou a influência de diversas variáveis por forma a inferir sobre a aplicabilidade prática deste processo. Pesticidas organoclorados apresentam maior resistência à degradação por processos oxidativos do que redutivos, sendo preferível o último na degradação desta importante classe de contaminantes. Como tal, o capítulo II se refere à degradação redutiva, por meio de diferentes metais de valência zero e partículas bimetálicas, do pesticida organoclorado CP. Além do amplamente explorado Fe0, outros metais podem ser aplicados neste processo, pelo que, neste estudo, explorou-se a potencialidade de Zn0 e Cu0 comparativamente ao primeiro. Ainda neste estudo foram investigadas duas formas de aumentar a reatividade dos metais: i) no caso do Fe0 e Zn0, revestindo com um metal mais nobre (Cu), por forma a observar o efeito catalisador do último no sistema bimetálico; ii) realizando um pré-tratamento à superfície dos metais.
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Johnson, Frank Orlando. "Behavioral outcomes and molecular marker modulation during learning and memory formation following developmental exposure to organophoshorus insecticides." Diss., Mississippi State : Mississippi State University, 2007. http://library.msstate.edu/etd/show.asp?etd=etd-03122009-143101.
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Sehgal, Blossom. "Stored-grain insect management with insecticides: evaluation of empty- bin and grain treatments against insects collected from Kansas farms." Thesis, Kansas State University, 2013. http://hdl.handle.net/2097/15528.
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Master of ScienceDepartment of Grain Science and Industry
Bhadriraju Subramanyam
The insecticides, β-cyfluthrin and chlorpyrifos-methyl plus deltamethrin, are approved in the United States for treating empty bin surfaces. Chlorpyrifos-methyl plus deltamethrin and spinosad insecticides are approved for direct treatment of wheat. The efficacy of commercial formulations of β-cyfluthrin and chlorpyrifos-methyl plus deltamethrin at labeled rates was evaluated against adults of 16 field strains of the red flour beetle, Tribolium castaneum (Herbst); seven strains of sawtoothed grain beetle, Oryzaephilus surinamensis (L.); and two strains of the lesser grain borer, Rhyzopertha dominica (F.). Concrete arenas in plastic Petri dishes (9 cm diameter) were used to simulate the concrete floor of empty bins. The time for ~100% knockdown and mortality of adults of laboratory strains of the three species was first established by exposing them to insecticide-treated concrete surfaces for 1 to 24 h. Adults of field strains of each species were exposed to specific established insecticide-time combinations. Mortality of all species was lower than knockdown, suggesting recovery after seven days when placed on food. Chlorpyrifos-methyl plus deltamethrin did not control all R. dominica and most O. ]surinamensis field strains. β-cyfluthrin was extremely effective against R. dominica but ineffective against T. castaneum and O. surinamensis field strains, even at four times the high labeled rate. Field strains of R. dominica were highly susceptible to spinosad and chlorpyrifos-methyl plus deltamethrin at labeled rates on hard red winter wheat. Strains of T. castaneum and O. surinamensis were susceptible only to the latter insecticide. Dose-response tests with spinosad on the two least susceptible field strains of each species showed the lethal dose for 99% mortality (LD[subscript]99) for T. castaneum and R. dominica field strains were similar to that of the corresponding laboratory strains. Corresponding values for the two O. surinamensis field strains were significantly greater (~6 times) than the laboratory strain. The effective dose for progeny reduction (ED[subscript]99) of only one R. dominica field strain was significantly greater (~2 times) than that of the laboratory strain. The baseline susceptibility data of field strains of three insect species to spinosad will be useful for monitoring resistance development once this product is commercially released as a grain protectant.
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Fernandes, Garcia Néio Lúcio. "Influência do pH do diluidor, na ação de caldas ixodicidas (amitraz, clorpirifós e cipermetrina), contra Rhipicephalus (Boophilus) microplus (Canestrini, 1887) (acarina: ixodidae) //." Jaboticabal : [s.n.], 2007. http://hdl.handle.net/11449/94652.
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Orientador: Adjair Antonio do NascimentoBanca: Gilson Pereira de Oliveira
Banca: Júlio Mendes
Resumo: O presente trabalho procurou verificar a possível interferência do pH do diluidor na eficiência de ixodicidas comerciais. Para tanto, utilizou-se amitraz, clorpirifós, cipermetrina, mais um grupo controle, para verificar os possíveis efeitos de soluções tampão com pH 3, 4, 5, 6, 7, 8, 9, 10 e 11, como diluidores dos ixodicidas, sobre as variáveis: peso médio da oviposição (PMO), relação PMOxPT (peso das teleóginas), porcentagem de eclosão (PE), eficiência reprodutiva (ER) e eficácia da calda (EC). Teleóginas de R. (B.) microplus, obtidas de bovinos infestados com cepa de campo, foram submetidas à biocarrapaticidogramas, uma hora e 24 horas após preparo (HAP) das caldas. O pH do diluente pouco influenciou na eficácia do amitraz nos parâmetros avaliados, embora as linhas de tendência dos resultados para ER e EC tenham mostrado menor ação do ixodicida, à medida que o pH do diluidor aumentava, tanto para uma HAP como para 24 HAP. Para o clorpirifós, os resultados obtidos mostraram diferenças significativas no PMO, PMOxPT e PE nos resultados de uma hora. A ER (uma HAP) e EC (24 HAP) foram influenciadas negativamente pelo pH quando este se elevava. As linhas de tendência dos resultados para ER e EC mostraram diminuição da ação à medida que o pH do diluidor aumentava, tanto para uma hora como para 24 horas. A cipermetrina sofreu pouca influência do pH. Entretanto, a linha de tendência dos resultados para EC foi influenciada pela elevação do pH, quando usada 24 HAP.
Abstract: The objective of the present research is to check, with commercial ixodicides, the possible interference of the pH of the thinner. For this amitraz, chlorpyrifos, cypermethrin, plus a control group, was used to verify the possible effects of buffer solutions with pH 3, 4, 5, 6, 7, 8, 9, 10 and 11, as thinners of the ixodicides, on the following: medium weight of egg mass (PMO), relationship PMOxPT (weight of the teleogines), percentage of larvae hatch (PE), estimated reproduction (ER) and % control (EC). Teleogines of R. (B.) microplus, obtained from cattle infested with field's strains have been submitted to the in vitro immersion tests, one hour and 24 hours after the solution has been prepared (HAP). The pH of the thinners made little difference on the amitraz on the parameters assessed and, statistically, did not show any significant differences, although the tendency of the results for ER and EC showed less action of ixodicide, as the pH of the thinner increased, as much for one HAP as for 24 HAP. As for chlorpyrifos, the results obtained, statistically showed significant differences on the PMO, PMOxPT and PE in the results of one hour. The ER (one HAP) and EC (24 HAP), were negatively affected by pH when this was augmented. The tendency of the results for ER and EC showed a diminution from the action, as the pH from the thinner augmented, as much for one HAP as for 24 HAP. The cypermetrin suffered less influence from pH. However, the tendency of the results for EC were affected by the elevation of pH, when used 24 HAP.
Mestre
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Okeke, Barbara C. "Utilizing urinary biomarkers in Egyptian adolescent applicators and non-applicators to characterize pesticide exposure to λ-cyhalothrin, α-cypermethrin, chlorpyrifos and profenofos applied on cotton crops over time." Diss., University of Iowa, 2018. https://ir.uiowa.edu/etd/6233.
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Organophosphates (OPs) and Pyrethroids (PYRs) are widely used pesticides in both agricultural and non-agricultural environments. In agricultural work settings, typically more than one pesticide is used in combination, or sequentially, to kill pests. There is currently a gap in research that looks at how exposures to multiple pesticides can impact human health – particularly among adolescents who work in these environments. The goal of this dissertation research was to examine the use of OP (chlorpyrifos, and profenofos) and PYR (λ-Cyhalothrin, α-Cypermethrin) pesticides across an application season and how exposure is associated with symptoms and cholinesterase enzyme activity, and to examine the impact of a sequential exposure to multiple OPs, and exposure to both OPs and PYRs. Urine and blood samples, questionnaire data, and a medical exam were collected over a 10-month period from adolescent pesticide applicators in Egypt. Overall, applicators had higher exposure than non-applicators to all four pesticides. The non-applicators were also exposed and had levels 4 times higher in urine metabolite levels than the general population in the U.S. In addition, these exposures caused increased symptoms and severity of symptoms among both applicators and non-applicators. In conclusion, adolescent agriculture workers in the Egyptian cotton fields are exposed to multiple pesticides and are susceptible to the impact of those exposures on their health.
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Lee, Iwa. "Developmental neurotoxicity of persistent and non-persistent pollutants : Behavioral and neurochemical assessments of a perfluorinated compound, pesticides and interaction effects." Doctoral thesis, Uppsala universitet, Institutionen för organismbiologi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-261742.
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The focus of this thesis was to investigate developmental neurotoxic effects of different persistent and non-persistent environmental pollutants, alone or in binary mixtures, when exposure occurs during a critical period of brain development, in mice. The compounds investigated included a perfluorinated compound, perfluorohexane sulphonate (PFHxS), and four different pesticides, endosulfan, cypermethrin, chlorpyrifos and carbaryl. Both persistent and non-persistent pollutants are detected in the environment and in humans, which shows that exposure to these compounds is occurring in real life. Humans can therefore be exposed to various pollutants during their whole lifetime, starting from the gestational period to adulthood. Furthermore, exposure to environmental pollutants is rarely exclusive to a single compound, but rather occurs through combinations of various pollutants present in the environment. Exposure to environmental pollutants during human brain development have been suggested to be a possible cause for neuropsychiatric disorders, such as autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD). Previous studies have shown that chemicals can induce irreversible disorders in brain function when exposure to these chemicals occurs during a critical defined period of the brain development known as the brain growth spurt (BGS). The BGS is characterized by a rapid growth and development of the immature brain. In humans, and mice, this period also overlaps the lactation period indicating that newborns and toddlers can be exposed via mothers’ milk as well. This thesis has shown that a single oral exposure to PFHxS, endosulfan, cypermethrin, chlorpyrifos or carbaryl can induce developmental neurotoxic effects in mice, when exposure occurs during a critical period of brain development. These effects are manifested as persistent altered adult spontaneous behavior in a novel home environment, modified habituation, altered susceptibility of the cholinergic system and changed levels of neuroproteins in the mouse brain. Furthermore, a single neonatal co-exposure to a binary mixture of carbaryl/chlorpyrifos or PFHxS/endosulfan can interact and exacerbate the adult behavioral effects. These effects were seen at dosages were the single compound did not elicit a response or induced a much weaker behavioral effect. This indicates that risk assessments conducted on single compounds might underestimate interaction effects of mixtures when co-exposed.
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Boggans, Trenell Davis. "Comparison of Modeled and Measured Pesticide Concentrations in Air." Scholar Commons, 2018. https://scholarcommons.usf.edu/etd/7478.
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Chlorpyrifos (CPF) is a popular organophosphorus insecticide that is heavily used in the agriculture industry as a means of pest control. Chlorpyrifos is known for its toxic effect to inhibit the enzyme acetylcholinesterase (ACHE) in humans and is widely used in areas of California where the site of application is close to occupied areas, such that exposures to residents and bystanders can occur due to secondary drift. Secondary drift refers to the volatilization of a pesticide from the surface to which it was applied (e.g. soil or plant foliage) and subsequent off-site movement in ambient air. Secondary drift is different from spray drift, which occurs during and very shortly after application. The goal of this thesis is to evaluate existing measurements of secondary drift from ambient air measurements of CPF available from California’s Air Monitoring Network (AMN), in comparison to predictions using a state-of-the-art dispersion model. Pesticide use data were obtained from the California Department of Pesticide Regulation (CDPR) website and was compiled to form scenarios to be modeled and compared against measurements taken throughout the year. Probability distributions for the measured and predicted CPF concentrations resulted in correlations ranging from 3% to 91% depending on the year and modeled scenario. Overall the model overpredicted air concentrations for the modeled scenarios, providing conservative values for risk assessment purposes.
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Marchand, Adrien. "Pertinence écologique des biomarqueurs d'immunotoxicité en surveillance environnementale . Evaluation of chlorpyrifos effects, alone and combined with lipopolysaccharide stress, on DNA integrity and immune responses of three-spined stickleback, Gasterosteus aculeatus." Thesis, Reims, 2018. http://www.theses.fr/2018REIMS049.
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Ce travail propose d’améliorer les connaissances sur la variabilité naturelle des immunomarqueurs cellulaires innées chez un poisson modèle en écotoxicologie, l’épinoche à trois-épines, Gasterosteus aculeatus. Il a pour but la détermination de valeurs de référence utilisables dans un contexte de biosurveillance passive pour chacun des immunomarqueurs considérés. Ainsi, l’effet de trois facteurs confondants, que sont la période de prélèvement, la taille et le sexe des organismes, a été étudié en conditions contrôlées de laboratoire. Il a été ainsi possible d’obtenir, pour chaque immunomarqueur, un modèle donnant sa valeur moyenne en fonction des trois facteurs confondants, ainsi qu’une plage de valeurs de référence laboratoire. Dans une optique d’utilisation en biosurveillance, il est important de savoir si ce modèle laboratoire peut être utilisé dans d’autres conditions. Dans un second temps, les plages de référence laboratoire ont été confrontées à des données issues de poissons élevés en conditions semi-naturelles (condition mésocosme) et à des données in situ d’un site témoin (condition terrain). Les résultats de cette confrontation ont permis la construction d’un modèle prédictif des variations naturelles des immunomarqueurs dans chaque condition expérimentale. Testées dans un contexte de biosurveillance, l’utilisation des plages de référence terrain a bien montré la capacité de discriminer les sites témoins et contaminés. De plus, cette méthode a favorisé la la détection de faux positifs, induits par une hétérogénéité morphologique des poissons prélevés sur les différents sites, issus des résultats obtenus avec des procédures statistiques classiquesThe natural variability of cellular innate immunomarkers in a model species in ecotoxicology, the three-spined stickleback, Gasterosteus aculeatus was studied in order to determine immunomarker reference values useful for passive biomonitoring Thus, effects of three confounding factors, sampling period, sex, and fish body size, were investigated in controlled laboratory conditions. This first phase enabled the construction of a mathematical model that predicts immunomarker mean values in function of the three considered confounding factors, along with a range of reference values in laboratory conditions. To be used for biomonitoring, it is important to know if the laboratory model is correctly predicting other conditions. Therefore, laboratory reference ranges were compared to data obtained from fish sampled in semi-natural conditions (mesocosm conditions) and fish sampled in natural conditions, in one uncontaminated site (field condition). Results of this comparison allowed to construct a predictive model of the natural variations of immunomarker values in each experimental condition. Tested in a biomonitoring context, the use of field reference range allowed to i) discriminate between contaminated and uncontaminated sites and ii) identify false positives that are due to the morphological heterogeneity of fish sampled in the different sites
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Acker, Carmine Inês. "Efeitos farmacológicos do disseleneto de difenila em modelos de toxicidade induzida por organofosforados em ratos." Universidade Federal de Santa Maria, 2012. http://repositorio.ufsm.br/handle/1/4461.
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Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorPesticides are substances used in agricultural areas and public health programs to control pests and disease vectors. Among pesticides, organophosphates (OPs) are considered the most toxic to vertebrates. Diphenyl diselenide [(PhSe)2] is an organoselenium compound that presents pharmacological activities, among that the antioxidant effect. Therefore, the aim of this study was to evaluate the pharmacological effects of (PhSe)2 in acute models of toxicity induced by chlorpyrifos (CPF) and acephate (AC) in rats, as well as to investigate the hyperglycemic and hyperlipidemic effects of CPF which has not been described. In the first experimental protocol (article 1), the effect of (PhSe)2 on hepatic and hematological toxicity induced by CPF in rats was evaluated. The animals were pre-treated by intragastric route (p.o.) with (PhSe)2 (5 mg/kg) once a day for 7 days. On the 8th and 9th days, (PhSe)2 (5 mg/kg; p.o.) was administered to rats 30 min prior to subcutaneous (s.c.) injection of CPF (50 mg/kg). Twenty-four hours after the last CPF injection, rats were killed. The aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) activities were determined in plasma of rats. Lipid peroxidation, protein carbonyl and non-protein thiol (NPSH) levels as well as catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR) and gluthatione S-transferase (GST) activities were determined in livers of rats. Hematologic parameters were also assayed. CPF caused an increase in AST, ALT and LDH activities, an increase in lipid peroxidation and protein carbonyl levels, a decrease in NPSH levels and an inhibition of CAT, GPx, SOD and GST activities. In addition, CPF exposure caused hematologic toxicity, evidenced mainly by a decrease in total leukocytes levels. (PhSe)2 protected against toxic effects induced by CPF in rats. Moreover, (PhSe)2 increased per se NPSH levels and GST activity in livers of rats. In the second experimental protocol (article 2), the effect of (PhSe)2 on metabolic disorders induced by AC in rats was investigated. (PhSe)2 (10 or 30 mg/kg; p.o.) was administered to rats 1 hour prior to AC administration (140 mg/kg; p.o.). Two hours after AC administration, rats were killed. Glucose and corticosterone levels as well as the lipid status were determined in plasma of rats. Cardiovascular risk factor and the atherogenic index were calculated. Glycogen levels as well as tyrosine aminotransferase (TAT) and glucose-6-phosphatase (G6Pase) activities were determined in livers of rats. Cerebral acetylcholinesterase (AChE) activity was assayed. AC induced an increase in glucose, corticosterone and triglycerides (TG) levels, an increase in TAT and G6Pase activities and an inhibition of AChE activity. The cardiovascular risk factor [(TG/ high density lipoprotein (HDL)] was increased in AC exposed rats. (PhSe)2 attenuated these alterations, except for the increase of corticosterone levels and AChE activity inhibition. In the third experimental protocol (article 3), the hyperglycemic and hyperlipidemic effects of CPF in rats were investigated. The mechanisms involved in hyperglycemia induced by CPF were also studied. CPF was administered once to rats at the dose of 50 mg/kg, s.c. Animals were killed at 2, 4, 8, 12 e 24 hours after CPF administration. Glucose and corticosterone levels as well as lipid status and paraoxonase-1 (PON-1) activity were determined in plasma of rats. Cardiovascular risk factors and the atherogenic index were calculated. Glycogen levels as well as TAT and G6Pase activities were determined in livers of rats. Cerebral AChE activity was assayed. CPF caused an increase in glucose, glycogen, corticosterone, TG and low density lipoprotein (LDL) levels, an increase in TAT and G6Pase activities, a decrease in HDL levels and PON-1 activity and AChE activity inhibition. The cardiovascular risk factors and atherogenic index were increased in CPF exposed rats. The results of the present study demonstrated that (PhSe)2 protected against toxic effects induced by CPF and AC in rats. CPF exposure caused hyperglycemia and hyperlipidemia in rats. The gluconeogenesis pathway activation is involved in the hyperglycemic effect caused by CPF. Considering that the crescent use of OPs worldwide has been the cause of many severe human poisoning cases, the results of the present work are of great importance, since that (PhSe)2 may represent an alternative to alleviate the OPs-induced toxicity.
Os agrotóxicos são substâncias empregadas nas áreas agrícolas e em programas de saúde pública, para o controle de pragas e vetores que transmitem doenças. Dentre os agrotóxicos, os inseticidas organofosforados (OFs) são considerados os mais tóxicos aos vertebrados. O disseleneto de difenila [(PhSe)2] é um composto orgânico de selênio para o qual já foram descritas diversas propriedades farmacológicas, entre elas a atividade antioxidante. Dessa forma, este trabalho teve como objetivos avaliar os efeitos farmacológicos do (PhSe)2 em modelos de toxicidade aguda induzida por clorpirifós (CPF) e acefato (AC) em ratos, bem como, avaliar os efeitos hiperglicêmico e hiperlipidêmico do CPF, os quais não estão descritos na literatura. No primeiro protocolo experimental (artigo 1), avaliou-se o efeito do (PhSe)2 na toxicidade hepática e hematológica induzida por CPF em ratos. Os animais foram pré-tratados com (PhSe)2 (5 mg/kg) pela via intragástrica (p.o.) uma vez ao dia durante 7 dias. No 8º e 9º dias o (PhSe)2 (5 mg/kg; p.o.) foi administrado 30 min antes da administração subcutânea (s.c.) de CPF (50 mg/kg). Os animais foram mortos vinte e quatro horas após a última administração de CPF. A atividade das enzimas aspartato aminotransferase (AST), alanina aminotransferase (ALT) e lactato desidrogenase (LDH) foram determinadas no plasma dos ratos. Os níveis de peroxidação lipídica, carbonilação de proteínas e tióis não-protéicos (SHNP), bem como a atividade das enzimas catalase (CAT), superóxido dismutase (SOD), glutationa peroxidase (GPx), glutationa redutase (GR) e glutationa S-transferase (GST) foram determinados no fígado dos ratos. Os parâmetros hematológicos também foram analisados. O CPF causou aumento da atividade das enzimas AST, ALT e LDH, aumento dos níveis de peroxidação lipídica e carbonilação de proteínas, diminuição dos níveis de SHNP e inibição das enzimas CAT, GPx, SOD e GST. Além disso, a exposição ao CPF causou toxicidade hematológica, evidenciada principalmente pela diminuição dos níveis de leucócitos totais. O (PhSe)2 protegeu contra os efeitos tóxicos induzidos pelo CPF em ratos. Além disso, o (PhSe)2 aumentou per se os níveis de SHNP e a atividade da GST no fígado dos ratos. No segundo protocolo experimental (artigo 2), investigou-se o efeito do (PhSe)2 nos distúrbios metabólicos induzidos por AC em ratos. O (PhSe)2 (10 ou 30 mg/kg; p.o.) foi administrado aos animais 1 hora antes da administração de AC (140 mg/kg; p.o.). Os animais foram mortos duas horas após a administração de AC. Os níveis de glicose e corticosterona bem como o perfil lipídico foram determinados no plasma dos ratos. Os fatores de risco cardiovascular e o índice aterogênico foram calculados. Os níveis de glicogênio bem como a atividade das enzimas tirosina aminotransferase (TAT) e glicose-6-fosfatase (G6Pase) foram analisados no fígado dos ratos. A atividade da acetilcolinesterase (AChE) cerebral também foi determinada. O AC causou aumento dos níveis de glicose, corticosterona e triglicerídios (TG), aumento da atividade das enzimas TAT e G6Pase e inibição da AChE. O fator de risco cardiovascular [(TG/lipoproteína de alta densidade (HDL)] aumentou nos ratos expostos ao AC. O (PhSe)2 atenuou essas alterações, exceto para o aumento dos níveis de corticosterona e para a inibição da AChE. No terceiro protocolo experimental (artigo 3), investigou-se o efeito hiperglicêmico e hiperlipidêmico do CPF em ratos. Também foram estudados os mecanismos envolvidos no efeito hiperglicêmico do CPF. O CPF foi administrado uma única vez na dose de 50 mg/kg, s.c.. Os animais foram mortos em diferentes tempos após a administração de CPF (2, 4, 8, 12 e 24 horas). Os níveis de glicose e corticosterona bem como o perfil lipídico e a atividade da paraoxonase-1 (PON-1) foram determinados no plasma dos ratos. Os fatores de risco cardiovascular e o índice aterogênico foram calculados. Os níveis de glicogênio bem como a atividade das enzimas TAT e G6Pase foram analisados no fígado dos ratos. A atividade da AChE cerebral também foi determinada. O CPF causou aumento dos níveis de glicose, glicogênio, corticosterona, TG e lipoproteína de baixa densidade (LDL), aumento da atividade das enzimas TAT e G6Pase, diminuição dos níveis de HDL e da atividade da PON-1 e inibição da atividade da AChE. Os fatores de risco cardiovascular e o índice aterogênico aumentaram nos animais expostos ao CPF. Os resultados do presente trabalho demonstraram que o (PhSe)2 protegeu contra a toxicidade induzida por CPF e AC em ratos. A exposição ao CPF causou hiperglicemia e hiperlipidemia em ratos. A ativação da via da gliconeogênese está envolvida no efeito hiperglicêmico causado pelo CPF. Considerando-se que a exposição aos OFs é cada vez mais freqüente e que é a causa de diversas doenças, os resultados deste trabalho são de grande importância, uma vez que o (PhSe)2 pode representar uma alternativa para atenuar a toxicidade causada pelos OFs.
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Quatrin, Gustavo Donato. "Validação analítica para determinação de clorpirifós e avaliação da eficiência do sistema biobed Brasil." Universidade Federal de Santa Maria, 2016. http://repositorio.ufsm.br/handle/1/10623.
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Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorThe storage and handling points of agricultural sprayers on farms are a contamination point source of punctual contamination in case of accidental spills of concentrated pesticide and / or leaks, among others. In order to avoid possible environmental contaminations, since the decade of 90 s have been developed biobed systems, where the handling of pesticides as well as agricultural implements washing are discharded on a mixture of straw, soil and peat (biomix). This mixture has the ability to retain and subsequently biodegrade pesticides. In this study was validated an analytical method applied for routine analysis to determine the organophosphate pesticide chlorpyrifos in biobeds. The method is based on 5 g sample extraction with 30 mL of acetone acidified with phosphoric acid 98:1:1 (v/v/v). After homogenization, centrifugation and filtration, 125 μL of the extract was evaporated and reconstituted in 5 mL of methanol acidified with 0.1% acetic acid. The analysis was performed on a liquid chromatographic system coupled to a tandem mass spectrometer (UPLC-MS/MS). The validation parameters evaluated were calibration curve linearity (r2), accuracy (spike and recovery %), limits of detection (LOD) and quantification (LOQ) of the instrument and the method, precision (RSD%) and matrix effect. To the linearity study analytical solutions were prepared in organic solvent and matrix extract at 0.1; 0.5; 1; 5; 20; 100; 250 ng mL-1. The recovery study was conducted on samples spiked at three concentrations (2, 10 and 50 mg kg-1) with seven replicates (n = 7) for each concentration and the values obtained were between 96 and 115% with RSD values lower than 20 % for all three concentration levels studied. The real LOQ obtained was 2 mg kg-1 and the matrix effect observed was lower than ± 20%, which demonstrates that there is not considerable suppression or enhancement in the analyte signal. The biobed system efficiently degraded chlorpyrifos in both 1) simulation of accidental spillage and 2) application of diluted pesticide solution. In the latter case, all the values obtained at the final sampling time (14 months) were below the real LOQm.
Os pontos de estocagem e manuseio de pulverizadores agrícolas em fazendas são uma fonte de contaminação pontual no caso de derrames acidentais do agrotóxico concentrado e/ou vazamentos. A fim de evitar possíveis contaminações ambientais, desde a década de 90 tem sido desenvolvidos sistemas de camas biológicas, onde o manejo de agrotóxicos bem como a lavagem de implementos agrícolas é feito sobre uma mistura de palha, solo e turfa. Esta biomistura tem a capacidade de reter e posteriormente biodegradar os agrotóxicos. Neste estudo foi validado um método para análises de rotina para determinação do agrotóxico organofosforado clorpirifós em camas biológicas. O método baseia-se na extração de 5 gramas de amostra com 30 mL de uma solução de acetona acidificada com ácido fosfórico 98:1:1 (v/v/v). Após homogeneização, centrifugação e filtração, 125 μL do extrato foi evaporado e reconstituído em 5 mL de metanol acidificado com 0,1% de ácido acético. A análise foi realizada em um sistema de cromatografia líquida acoplado a um espectrômetro de massas tandem (UPLC-MS/MS). Os parâmetros de validação avaliados foram linearidade da curva analítica (r2), exatidão (fortificação e recuperação em %), limites de detecção (LOD) e quantificação (LOQ) do instrumento e do método, precisão (RSD %) e efeito matriz. Para o estudo de linearidade as soluções analíticas foram preparadas em solvente orgânico e em extrato de matriz, a 0,1; 0,5; 1; 5; 20; 100; 250 ng mL-1. O estudo de recuperação foi realizado em amostras fortificadas em três concentrações (2, 10 e 50 mg kg-1) repetido sete vezes (n=7) para cada concentração. Os valores obtidos ficaram entre 96 e 115% com valores de RSD inferiores a 20% para os três níveis de concentração estudados. O LOQ real obtido foi 2 mg kg-1. O efeito matriz observado foi inferior a ± 20%, o que demonstra que não há supressão ou aumento considerável no sinal do analito. O sistema de camas biológicas foi eficiente para a degradação de clorpirifós em ambos 1) simulação de derrame acidental e 2) aplicação de solução diluída do agrotóxico. Neste último caso, todos os valores obtidos ao final das etapas de amostragem (14 meses) ficaram abaixo do LOQm real.