Search results for "Pesticides"
showing 10 items of 251 documents
Biodegradation of oganophosphorus pesticides by soil bacteria
2009
A number of studies in the 1980s and 1990s showed that crop-protection products, applied to drained fields, could move downwards through the soil profile and to the groundwater. Organophosphorus insecticides (OPs) are used all over the world for crop protection, for other agricultural practices such as sheep dipping and, in aquaculture, for the control of sea lice. Ops besides showing a specific neurotoxicity and have also been related to various modern diseases, including Creutzfeldt–Jakob (CJD) and the Gulf War syndrome. Although OPs are less persistent than Organoclorine pesticides (OCs), they still constitute an environmental risks thus increasing the social concern about their levels i…
Preparation and preliminary biological screening of cholic acid–juvenoid conjugates
2020
Abstract Steroidal compounds have been utilized as carriers and for modification of physico-chemical properties of model biologically active secondary alcohols – juvenoids. Juvenoids are juvenile hormone analogues – environmentally safe insecticides, possessing significant biological activity towards different arthropods groups in focus on insect pest species. Structure modification of juvenoids plays important role to control the rate of liberation and decomposition of juvenoid in digestive system and can also play important role in the mode of action towards selected insect. This study presents an approach to the synthesis of steroidal monomers and dimers carrying one and two molecules of…
Organic residues in lake and drinking water from the lagoa de Juturnaíba (região dos lagos - RJ, Brazil)
1997
Various analytical methods for the determination of organic residues in water were applied to samples from the Lagoa de Juturnaíba in the Região dos Lagos, east of Rio de Janeiro. The concentrations of more than 60 pesticides and of different aminopolycarboxylic acids were determined using GC/MS detection, and a GC/MS screening procedure was applied to detect additional compounds. None of the investigated pesticide residues could be detected in the lake water at detection limits of less than 100 ng/L. EDTA was detected at a concentration level of 2 mg/L in the lake and in drinking water prepared from this lake. Traces of biphenyl were identified by GC/MS in the lake water, the source of whi…
The effects of alpha-cypermethrin exposure on biochemical and redox parameters in pregnant rats and their newborns
2016
IF 2.388; International audience; Pyrethroid insecticides are extensively used in agriculture and in household activities. During pregnancy, they might affect maternal metabolic status and there after fetal development. In this work, we studied metabolic and redox effects of low dose alpha-cypermethrin exposure in pregnant rats and their offspring. The diet containing alpha cypermethrin at 0.02 mg/kg/day was consumed during the entire gestation. Plasma biochemical parameters as well as liver lipid and oxidative stress markers were determined. Our results showed that alpha-cypermethrin induced an increase in body weight and in plasma glucose and lipid levels, as well as in plasma aspartate a…
Selective chromo-fluorogenic detection of DFP (a Sarin and Soman mimic) and DCNP (a Tabun mimic) with a unique probe based on a boron dipyrromethene …
2014
[EN] A novel colorimetric probe (P4) for the selective differential detection of DFP (a Sarin and Soman mimic) and DCNP (a Tabun mimic) was prepared. Probe P4 contains three reactive sites; i.e. (i) a nucleophilic phenol group able to undergo phosphorylation with nerve gases, (ii) a carbonyl group as a reactive site for cyanide; and (iii) a triisopropylsilyl (TIPS) protecting group that is known to react with fluoride. The reaction of P4 with DCNP in acetonitrile resulted in both the phosphorylation of the phenoxy group and the release of cyanide, which was able to react with the carbonyl group of P4 to produce a colour modulation from pink to orange. In contrast, phosphorylation of P4 with…
Risk factors for central nervous system tumors in children: New findings from a case-control study
2017
BACKGROUND: Central nervous system tumors (CNS) are the most frequent solid tumor in children. Causes of CNS tumors are mainly unknown and only 5% of the cases can be explained by genetic predisposition. We studied the effects of environmental exposure on the incidence of CNS tumors in children by subtype, according to exposure to industrial and/or urban environment, exposure to crops and according to socio-economic status of the child. METHODS: We carried out a population-based case-control study of CNS tumors in Spain, covering 714 incident cases collected from the Spanish Registry of Childhood Tumors (period 1996-2011) and 4284 controls, individually matched by year of birth, sex, and au…
Prediction of acute toxicity of organophosphorus pesticides using topological indices
2007
Topological indices were used in the prediction of the acute toxicity (intraperitoneal and oral LD(50)) of organophosphorus pesticides on rats. Models with six variables for the prediction of LD(50)-i.p. (r = 0.849, Q(2) = 0.613) and eight variables for LD(50)-oral (r = 0.906, Q(2) = 0.701) were selected. External group and cross-validation by use of leave-n-out tests were also performed in order to assess the stability and the prediction performance of the selected topological models.
Dynamics and risk assessment of pesticides in cucumber through field experiments and model simulation
2020
Abstract Pesticides are often applied multiple times during cucumber cultivation in China. In order to obtain the residue concentrations and subsequently human health risk assessment after pesticide multiple applications, plenty of field trials have been conducted, consuming a lot of labor force and funds. The application of kinetic models can address this problem to some extent by predicting the residue values of pesticides in cucumber. In this study, a dynamic model (dynamiCROP) was applied in combination with field experiments to investigate the distribution, translocation, and dissipation after the one-time application of seven pesticides in a cucumber-soil environment. Moreover, the re…
Utilization of long duration high-volume sampling coupled to SPME-GC-MS/MS for the assessment of airborne pesticides variability in an urban area (St…
2016
Atmospheric samples have been collected between 14 March and 12 September 2012 on a 2-week basis (15 days of sampling and exchange of traps each 7 days) in Strasbourg (east of France) for the analysis of 43 pesticides. Samples (particle and gas phases) were separately extracted using Accelerated Solvent Extraction (ASE) and pre-concentrated by Solid Phase Micro-Extraction (SPME) before analysis by gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). Four SPME consecutive injections at distinct temperatures were made in order to increase the sensitivity of detection for the all monitored pesticides. Currently used detected pesticides can be grouped in four classes; those used i…
Determination of organochlorine pesticide residues in honey from the central zone of Portugal and the Valencian community of Spain
2004
In this study nine organochlorine pesticide residues ([alpha]-, [beta]-, and [gamma]-hexachlorocyclohexane (HCH), hexachlorobenzene (HCB), aldrin, p,p'-DDE, p,p'-DDD, o,p'-DDT, and p,p'-DDT) in forty nine samples of honey collected from markets of Portugal and Spain during 2001 and 2002, respectively, were evaluated. For this evaluation, three analytical procedures were studied. The analytical procedure, based on LLE extraction with ethyl acetate followed by gas chromatography-electron-capture detection (GC-ECD) for quantification, and mass spectrometry (GC-MS) for confirmation, has been selected. Recoveries of spiked samples ranged from 68%, for [beta]-HCH, and 126% for p,p'-DDT, for forti…