Search results for "Dimethoate"
showing 10 items of 12 documents
Influence of pesticide use in fruit orchards during blooming on honeybee mortality in 4 experimental apiaries
2016
Samples of dead honey bees (Apis mellifera L.) were collected periodically from 4 different locations during citrus and stone fruit trees blooming season to evaluate the potential impact of agrochemicals on honey bee death rate. For the determination of mortality, dead honey bee traps were placed in front of the experimental hives entrance located in areas of intensive agriculture in Valencian Community (Spain). A total of 34 bee samples, obtained along the monitoring period, were analyzed by means of QuEChERS extraction method and screened for 58 pesticides or their degradation products by LC-MS/MS. An average of four pesticides per honey bee sample was detected. Coumaphos, an organophosph…
Probable progress in the therapy of organophosphate poisoning
1976
Whether or not extracorporeal hemodialysis or hemoperfusion with coated activated charcoal might be used in eliminating organophosphates following poisoning with nitrostigmine, demeton-S-methyl sulfoxide, or dimethoate was here examined. Nitrostigmine could not be hemodialysed. The other two organophosphates, on the other hand could be well eliminated from the blood by hemodialysis. The clearance rates for demeton-S-methyl sulfoxide and dimethoate were 52.98 ml/min and 59.07 ml/min respectively, at a blood flow rate of 100 ml/min. The clearance values for hemoperfusion with coated activated charcoal were higher under the same trial conditions, the values being 83.70 ml/min for demeton-S-met…
GC–MS characterization of contemporary pesticides in PM10 of Valencia Region, Spain
2012
Pesticides in the inhalable fraction of particulate matter (PM10) should be well tracked in order to contribute information to future exposure assessment in individuals of the general public. A total of 40 current-used pesticides and metabolites were searched for in ambient air samples collected from January through December 2010. The samples were taken from one remote, one urban and three rural sites in Valencia Region (Spain) and analyzed using liquid chromatography coupled to mass spectrometry in tandem (LC-MS/MS). In the PM10 fraction 17 pesticides and metabolites were detected overall, two of them currently banned (carbofuran and omethoate, although the latter is a metabolite of the pe…
Therapeutic properties of haemodialysis and blood exchange transfusion in organophosphate poisoning
1976
Human blood was contaminated with nitrostigmine, dimethoate and demeton-S-methyl sulfoxide. It was then dialysed, concentrations of organophosphates were determined and dialysance values calculated. The influence of blood exchange transfusion on poison elimination as well as on the cholinesterase activity of blood, brain and muscle was studied in rats poisoned with nitrostigmine. Haemodialysis was found to be quite an effective method for eliminating demeton-S-methyl sulfoxide and dimethoate, dialysance values of 52.98 ml/min and 59.07 ml/min being found for demeton-S-methyl sulfoxide and dimethoate respectively. Nitrostigmine could not be removed by haemodialysis. These findings suggest th…
Determination of triazines and organophosphorus pesticides in water samples using solid-phase extraction.
1991
Abstract Octadecyl (C 18 )-bonded porous silica was evaluated for the extraction of triazine and organophosphorus pesticides from natural water. The extraction results showed an effective performance when 1 l of water was passed through small glass columns containing 500 mg of 50–100-μm C 18 bonded porous silica. The absorbed compounds were removed with ethyl acetate, evaporated to 200 μl and determined by gas chromatography. The overall average recoveries were greater than 85% except for dimethoate and trichlorfon. Application of this procedure to the analysis of natural water samples gave results that agree well with those obtained by solvent extraction methods.
Effects of dimethoate and benomyl on soil organisms and soil processes – a microcosm study
1998
Abstract Effects of two pesticides, dimethoate, an insecticide, and benomyl, a fungicide, applied singly or together, on soil organisms and plant growth were studied in microcosms containing agricultural soil and indigenous soil fauna together with introduced invertebrates and barley. Dimethoate reduced soil microarthropod populations and the reduction was stronger in the upper than in the lower soil layer. The collembolan community structure was affected by both pesticides. Populations of microarthropods in pesticide-treated microcosms recovered during the experiment but the community structures remained differentiated. Total numbers of enchytraeids and nematodes were not affected by eithe…
Effect of soil moisture on pesticide toxicity to an enchytraeid worm, Enchytraeus sp.
1997
The aim of the study was to find out whether soil moisture affects toxicity of organic pesticides to an enchytraeid worm. Laboratory experiments were carried out with dimethoate and benomyl, using a small Enchytraeus sp. as the test species. Substrate was natural agricultural field soil cultivated without pesticides for several years. Experimental design consisted of three soil moistures (40, 55, and 70% of water holding capacity) and five pesticide concentrations, plus controls. Measured parameters were survival, size of the parent worms and number and size of juveniles produced. Dimethoate was relatively non-toxic to this species. Dimethoate did not decrease survival, but sublethal effect…
Toxicity of Dimethoate to Some Soil Animal Species in Different Soil Types
1996
Toxicity of dimethoate (insecticide) to an earthworm (Aporrectodea caliginosa tuberculata), a collembola (Folsomia candida), and an enchytraeid worm (Enchytraeus crypticus/variatus) was studied in three different soil types (artificial soil, clayey soil, and humus sandy soil). Parameters measured were survival and biomass change of the earthworms and survival and reproduction of the collembolas and enchytraeids. The degradation of dimethoate was analyzed too. Toxic effects were observed at the concentrations of some mg/kg dry soil. The biomass reduction of the earthworms occurred at lower concentrations than reduction in survival. The collembolas were more susceptible to dimethoate than the…
Temperature–Time Relationship in Collembolan Response to Chemical Exposure
1999
Abstract Effects of temperature on chemical toxicity to a collembolan, Folsomia candida , in relation to time were studied in this experiment. Field soil was used as a test substrate. Collembolans were incubated at three different temperatures (+13, +16, and +19°C) and in two different dimethoate concentrations (1 and 3 mg/kg), clean soil serving as the control. Four destructive samplings were done at 2-week intervals. Dimethoate degradation was also analyzed. Dimethoate 1 mg/kg had a slight effect on both adult growth and reproduction, whereas 3 mg/kg was fatal to F. candida in the soil used. Toxic effects tended to last longer at low temperature than at high temperature, but the differenc…
Influence of organophosphate poisoning on human dendritic cells.
2013
Organophosphourus compounds (OPC, including nerve agents and pesticides) exhibit acute toxicity by inhibition of acetylcholinesterase. Lung affections are frequent complications and a risk factor for death. In addition, epidemiological studies reported immunological alterations after OPC exposure. In our experiments we investigated the effects of organophosphourus pesticides dimethoate and chlorpyrifos on dendritic cells (DC) that are essential for the initial immune response, especially in the pulmonary system. DC, differentiated from the monocyte cell line THP-1 by using various cytokines (IL-4, GM-CSF, TNF-α, Ionomycin), were exposed to organophosphourus compounds at different concentrat…