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Archives of Environmental Contamination... Jul 2014This study investigated organophosphorus (OP) residues in vegetables from 27 farms, 106 markets, and 1 supermarket around Kwan Phayao Lake, Northern Thailand, between...
This study investigated organophosphorus (OP) residues in vegetables from 27 farms, 106 markets, and 1 supermarket around Kwan Phayao Lake, Northern Thailand, between August and September 2013. Types of vegetables sampled were all vegetables cultivated or sold around the study site. The most common OP pesticides detected in farm samples were chlorpyrifos (50 %), malathion (31.8 %), monocrotophos (31.8 %), diazinon (13.6 %), omethoate (13.6 %), and dicrotophos (9.1 %). The most common OP pesticides detected in market samples were chlorpyrifos (33.9 %), diazinon (18.6 %), parathion-methyl (3.4 %), profenofos (3.4 %), primiphos-ethyl (3.4 %), and fenitrothion (1.7 %). The OP pesticides detected in supermarket samples were chlorpyrifos (33.3 %), and diazinon (66.7 %). Among the compounds detected, chlorpyrifos was detected in most of the vegetable samples from all sources. The highest chlorpyrifos level in farm samples were found in lemon balm (2.423 mg/kg) followed by Vietnamese coriander (0.835 mg/kg), and cowpea (0.027 mg/kg). The highest level in markets samples were found in garlic (7.785 mg/kg) followed by Chinese cabbage (2.864 mg/kg) and Vietnamese coriander (1.308 mg/kg). Residues from supermarket samples were found only in parsley (0.027 mg/kg). The findings showed that 16 samples (59.3 %) from farms and 14 samples (13.2 %) from markets contained OP residues at or above the maximum residue limits established by the European Union. It is concluded that awareness, safety education, and strict regulation of pesticide use are necessary.
Topics: Environmental Monitoring; Environmental Pollutants; Food Contamination; Lakes; Organophosphorus Compounds; Pesticide Residues; Thailand; Vegetables
PubMed: 24609615
DOI: 10.1007/s00244-014-0014-x -
The Southeast Asian Journal of Tropical... Nov 2013Agricultural pesticide utilization is one of the important problems in rural and urban crop-cultivated areas, with the majority of pollutants dispersing via ambient air,...
Agricultural pesticide utilization is one of the important problems in rural and urban crop-cultivated areas, with the majority of pollutants dispersing via ambient air, water and other natural pathways. This study was therefore conducted in a specially selected village which is known to be a leading vegetable growing area in Khon Kaen Province. The aim of the study was to assess pesticide residues, and measure the seasonal fluctuations in organophosphate concentrations during 2010 in the environment of a risk area. Samples from selected sites were collected in two phases: Phase I was in summer (during March to May) and Phase II was in winter (during October to December). A total of 150 samples were analyzed using gas chromatography with flame photometric detection. The results showed that dicrotophos, chlorpyrifos, profenofos and ethion were found at the highest concentrations in soil and at the lowest concentrations in ambient air (p<0.001). The highest mean concentration of a pesticide in ambient air samples was 0.2580 +/- 0.2686 mg/m(3) for chlorpyrifos in summer and 0.1003 +/- 0.0449 mg/m(3) for chlorpyrifos in winter. In surface water samples, the highest mean concentration of a pesticide was 1.3757 +/- 0.5014 mg/l for dicrotophos in summer and 0.3629 +/- 0.4338 mg/l for ethion in winter. The highest mean concentration of a pesticide in soil samples was 42.2893 +/- 39.0711 mg/kg ethion in summer and 90.0000 +/- 24.1644 mg/kg of ethion in winter.
Topics: Agriculture; Air; Environmental Exposure; Humans; Organophosphates; Pesticide Residues; Soil; Thailand; Vegetables; Water
PubMed: 24450247
DOI: No ID Found -
Water Science and Technology : a... 2013This paper examines the interaction between dissolved natural organic matter and pesticide residues, both of which are found in raw water sources, using three...
This paper examines the interaction between dissolved natural organic matter and pesticide residues, both of which are found in raw water sources, using three dimensional excitation-emission matrix (3DEEM) fluorescence spectroscopy. It was observed that pesticide residue at 0.1 mg L(-1) formed a complex with humic-like fluorophores that are commonly found in raw water samples. Applying 3DEEM fluorescence to investigate the humic fractions, it was found that identification of changes in water sources was possible, and, importantly, the presence of a number of pesticides was able to be determined. In addition, the formation of this complex, and the influence of soluble cations and anions upon it, was shown to impact the efficiency of analytical extraction procedures for pesticides; however, 3DEEM fluorescence could be an approach to account for such losses.
Topics: Atrazine; Benzopyrans; Humic Substances; Monocrotophos; Organophosphorus Compounds; Pesticide Residues; Simazine; Spectrometry, Fluorescence; Tannins; Triazines; Water Pollutants, Chemical
PubMed: 23752373
DOI: 10.2166/wst.2013.133 -
Journal of Wildlife Diseases Jul 2012Common Quail (Coturnix coturnix) were subjected to controlled and replicated experiments in the summer of 2008 to investigate the effects of short-term dehydration on...
Combined effect of short-term dehydration and sublethal acute oral dicrotophos exposure confounds the diagnosis of anticholinesterase exposure in common quail (Coturnix coturnix) using plasma cholinesterase activity.
Common Quail (Coturnix coturnix) were subjected to controlled and replicated experiments in the summer of 2008 to investigate the effects of short-term dehydration on cholinesterase activity in brain and plasma and the interaction between dehydration and exposure to the organophosphorus pesticide dicrotophos in these same tissues. Our objective was to determine if dehydration could confound the diagnosis of anticholinesterase exposure using inhibition of cholinesterase activity in quail tissues. The effect of dehydration was quantified using measures of plasma osmolality and hematocrit. Dicrotophos exposure caused significant inhibition of cholinesterase activity in brain, while the effects of dehydration and interaction were not significant. Dehydration caused significant duration-dependent increases in plasma osmolality and hematocrit. Dehydration also caused a significant increase in plasma cholinesterase activity. Variation in the change in plasma cholinesterase activity in response to dehydration was significantly and positively correlated with dehydration-induced variation in both the change in plasma osmolality and the change in hematocrit. These correlations suggest that plasma cholinesterase activity in quail is not limited to plasma but occupies some larger pool of the extracellular fluid volume, and we suggest lymph is part of that pool. The effects of dehydration on plasma cholinesterase activity masked the inhibitory effects of dicrotophos. Here, the combination of dehydration and dicrotophos exposure produced plasma cholinesterase activity that was not significantly different from reference and pre-exposure values, confounding the diagnosis of anticholinesterase exposure in dehydrated, dicrotophos-exposed quail. A method to adjust plasma cholinesterase activities for the confounding effects of dehydration and enable the diagnosis of anticholinesterase exposure in dehydrated, dicrotophos-exposed quail was developed. Clinicians and practitioners responsible for the diagnosis of anticholinesterase exposure in birds are cautioned that dehydration, commonly observed in sick wildlife, may mask the effect of anticholinesterases on plasma cholinesterase activity.
Topics: Animals; Bird Diseases; Brain; Cholinesterase Inhibitors; Coturnix; Dehydration; Environmental Exposure; Female; Hematocrit; Insecticides; Male; Organophosphorus Compounds; Osmolar Concentration
PubMed: 22740535
DOI: 10.7589/0090-3558-48.3.695 -
Environmental Toxicology May 2012Dicrotophos is a systemic insecticide with a wide range of applications. We investigated the genotoxicity of dicrotophos using the Ames test, the chromosome aberration...
Dicrotophos is a systemic insecticide with a wide range of applications. We investigated the genotoxicity of dicrotophos using the Ames test, the chromosome aberration test in CHO-K1 cells, and the comet assay in the Hep G2 cells, while this chemicals' toxicity to both the cell lines was evaluated with the MTT assay. Results showed that dicrotophos did not show any cytotoxicity to CHO-K1 cells, whereas it was cytotoxic to HepG2 cells incubated for 24 h but not for 2 h. For genotoxicity of dicrotophos, a significant change in the numbers of bacterial reveratnts using Salmomella typhimurium TA97a, TA98, TA100, TA102, and TA1535 as the tester strains, an increase in the frequencies of chromosome aberration in CHO-K1 cells, and an induced DNA damage in HepG2 cells were observed, indicating that dicrotophos was genotoxic in these three performed assays. From this study, we provide further evidence towards of genotoxic effects of dicrotophos.
Topics: Animals; CHO Cells; Chromosome Aberrations; Comet Assay; Cricetinae; Cricetulus; DNA Damage; Hep G2 Cells; Humans; Insecticides; Mutagenicity Tests; Mutagens; Organophosphorus Compounds; Salmonella typhimurium
PubMed: 22499550
DOI: 10.1002/tox.20645 -
Neurotoxicology and Teratology 2011Age-related differences in the acute neurotoxicity of cholinesterase (ChE)-inhibiting pesticides have been well-studied for a few organophosphates, but not for many...
Age-related differences in the acute neurotoxicity of cholinesterase (ChE)-inhibiting pesticides have been well-studied for a few organophosphates, but not for many others. In this study, we directly compared dose-responses using brain and red blood cell (RBC) ChE measurements, along with motor activity, for mevinphos, monocrotophos, dicrotophos, and phosphamidon. Long-Evans hooded male rats were tested as adults and at postnatal day (PND) 17; PND11 pups were also tested with dicrotophos only. All chemicals were administered via oral gavage and tests were conducted at times intended to span peak behavioral and ChE effects. All OPs tested produced a rapid onset and recovery from the behavioral effects. There were age-related differences in the inhibition of brain, but not necessarily RBC, ChE. Mevinphos was clearly more toxic, up to 4-fold, to the young rat. On the other hand, monocrotophos, dicrotophos, and phosphamidon were somewhat more toxic to the young rat, but the magnitude of the differences was < 2-fold lower. Motor activity was consistently decreased in adults for all chemicals tested; however, there was more variability with the pups and clear age-related differences were only observed for mevinphos. These data show that three of these four OPs were only moderately more toxic in young rats, and further support findings that age-related differences in pesticide toxicity are chemical-specific.
Topics: Aging; Animals; Animals, Newborn; Behavior, Animal; Brain; Cholinesterase Inhibitors; Cholinesterases; Dose-Response Relationship, Drug; Erythrocytes; Male; Mevinphos; Monocrotophos; Motor Activity; Neurotoxicity Syndromes; Organophosphorus Compounds; Pesticides; Phosphamidon; Rats; Rats, Long-Evans
PubMed: 21679767
DOI: 10.1016/j.ntt.2011.05.012 -
Pest Management Science Mar 2011The commercialization of new insecticides is important for ensuring that multiple effective product choices are available. In particular, new insecticides that exhibit...
BACKGROUND
The commercialization of new insecticides is important for ensuring that multiple effective product choices are available. In particular, new insecticides that exhibit high potency and lack insecticidal cross-resistance are particularly useful in insecticide resistance management (IRM) programs. Sulfoxaflor possesses these characteristics and is the first compound under development from the novel sulfoxamine class of insecticides.
RESULTS
In the laboratory, sulfoxaflor demonstrated high levels of insecticidal potency against a broad range of sap-feeding insect species. The potency of sulfoxaflor was comparable with that of commercial products, including neonicotinoids, for the control of a wide range of aphids, whiteflies (Homoptera) and true bugs (Heteroptera). Sulfoxaflor performed equally well in the laboratory against both insecticide-susceptible and insecticide-resistant populations of sweetpotato whitefly, Bemisia tabaci Gennadius, and brown planthopper, Nilaparvata lugens (Stål), including populations resistant to the neonicotinoid insecticide imidacloprid. These laboratory efficacy trends were confirmed in field trials from multiple geographies and crops, and in populations of insects with histories of repeated exposure to insecticides. In particular, a sulfoxaflor use rate of 25 g ha(-1) against cotton aphid (Aphis gossypii Glover) outperformed acetamiprid (25 g ha(-1) ) and dicrotophos (560 g ha(-1) ). Sulfoxaflor (50 g ha(-1) ) provided a control of sweetpotato whitefly equivalent to that of acetamiprid (75 g ha(-1) ) and imidacloprid (50 g ha(-1) ) and better than that of thiamethoxam (50 g ha(-1) ).
CONCLUSION
The novel chemistry of sulfoxaflor, its unique biological spectrum of activity and its lack of cross-resistance highlight the potential of sulfoxaflor as an important new tool for the control of sap-feeding insect pests.
Topics: Animals; Aphids; Hemiptera; Heteroptera; Insecticide Resistance; Insecticides; Pest Control, Biological; Sulfur Compounds
PubMed: 21308958
DOI: 10.1002/ps.2069 -
Toxicology Mar 2011A variety of chemicals, such as organophosphate (OP) and carbamate pesticides, nerve agents, and industrial chemicals, inhibit acetylcholinesterase (AChE) leading to...
A variety of chemicals, such as organophosphate (OP) and carbamate pesticides, nerve agents, and industrial chemicals, inhibit acetylcholinesterase (AChE) leading to overstimulation of the cholinergic nervous system. The resultant neurotoxicity is similar across mammalian species; however, the relative potencies of the chemicals across and within species depend in part on chemical-specific metabolic and detoxification processes. Carboxylesterases and A-esterases (paraoxonases, PON) are two enzymatic detoxification pathways that have been widely studied. We used an in vitro system to measure esterase-dependent detoxification of 15 AChE inhibitors. The target enzyme AChE served as a bioassay of inhibitor concentration following incubation with detoxifying tissue. Concentration-inhibition curves were determined for the inhibitor in the presence of buffer (no liver), rat liver plus calcium (to stimulate PONs and thereby measure both PON and carboxylesterase), and rat liver plus EGTA (to inhibit calcium-dependent PONs, measuring carboxylesterase activity). Point estimates (concentrations calculated to produce 20, 50, and 80% inhibition) were compared across conditions and served as a measure of esterase-mediated detoxification. Results with well-known inhibitors (chlorpyrifos oxon, paraoxon, methyl paraoxon, malaoxon) were in agreement with the literature, serving to support the use of this assay. Only a few other inhibitors showed slight or a trend towards detoxification via carboxylesterases or PONs (mevinphos, aldicarb, oxamyl). There was no apparent PON- or carboxylesterase-mediated detoxification of the remaining inhibitors (carbofuran, chlorfenvinphos, dicrotophos, fenamiphos, methamidophos, methomyl, monocrotophos, phosphamidon), suggesting that the influence of esterases on these chemicals is minimal. Thus, generalizations regarding these metabolic pathways may not be appropriate. As with other aspects of AChE inhibitors, their metabolic patterns appear to be chemical-specific.
Topics: Animals; Aryldialkylphosphatase; Calcium; Carboxylesterase; Chlorpyrifos; Cholinesterase Inhibitors; Dose-Response Relationship, Drug; Esterases; In Vitro Techniques; Inactivation, Metabolic; Liver; Male; Rats; Rats, Long-Evans
PubMed: 21237238
DOI: 10.1016/j.tox.2011.01.002 -
Journal of Economic Entomology Oct 2010The invasive Argentine ant, Linepithema humile (Mayr), has become a worldwide problem capable of inflicting significant ecological and economic injury on urban,...
The invasive Argentine ant, Linepithema humile (Mayr), has become a worldwide problem capable of inflicting significant ecological and economic injury on urban, agricultural, and natural environments. The mobility of this pest ant has long been noted, rapidly moving nests to new food resources and then away as resources are depleted. This ant, like many pest ant species, has a special affinity for honeydew excreted by phloem-feeding Hemiptera. We investigated the effect of various hemipteran control strategies on terrapin scale densities and measured their indirect effect on local Argentine ant densities and foraging effort. We then determined whether this indirect treatment strategy improved the performance of an ant bait. We predicted that Argentine ants would move nests away from trees treated for Hemiptera and then move nests back when a liquid bait was offered, followed by a decline in ant numbers due to intake of the toxicant. A horticultural oil spray and soil application of the systemic insecticide, imidacloprid, had no effect on terrapin scale numbers. However, trunk-injected dicrotophos caused a reduction in scale and a decline in local Argentine ant nest density and canopy foraging effort. We also recorded a reduction in local Argentine ant ground foraging when large amounts of liquid bait were applied, and we found no evidence that combining dicrotophos with liquid ant bait performed better than each treatment alone. We suggest that a strategy of combined hemipteran control plus application of liquid ant bait can reduce local Argentine ant densities, when both components of this system are highly efficacious.
Topics: Acer; Animals; Ants; Argentina; Hemiptera; Insect Control; Mineral Oil; Oils; Phloem
PubMed: 21061981
DOI: 10.1603/ec10150 -
Journal of Environmental and Public... 2009This study investigated inhalation exposure to organophosphate pesticides (OPPs) and evaluated the associated health risks to vegetable growers living in the Bang-Rieng...
This study investigated inhalation exposure to organophosphate pesticides (OPPs) and evaluated the associated health risks to vegetable growers living in the Bang-Rieng agricultural community. Air samples were collected by using personal sampling pumps with sorbent tubes placed in the vegetable growers' breathing zone. Samples were collected during both wet and dry seasons. Residues of organophosphate pesticides, that is, chlorpyrifos, dicrotofos, and profenofos, were analyzed from 33 vegetable growers and 17 reference subjects. Results showed that median concentrations of OPPs in air in farm areas were in the range of 0.022-0.056 mg/m(3) and air in nonfarm areas in the range of <0.0016-<0.005 mg/m(3). The concentration of the three pesticides in the vegetable growers was significantly higher than that of the references during both seasons. The results also indicate that the vegetable growers may be at risk for acute adverse effects via the inhalation of chlorpyrifos and dicrotofos during pesticide application, mixing, loading, and spraying. It is suggested that authorities and the community should implement appropriate strategies concerning risk reduction and risk management.
Topics: Adult; Agriculture; Air; Air Pollutants, Occupational; Chlorpyrifos; Cross-Sectional Studies; Female; Humans; Inhalation Exposure; Male; Occupational Exposure; Organophosphates; Organophosphorus Compounds; Organothiophosphates; Pesticides; Risk; Thailand; Vegetables
PubMed: 20168980
DOI: 10.1155/2009/452373