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Sample records for phenotype chlorpyrifos diazinon

  1. Developmental neurotoxicants target neurodifferentiation into the serotonin phenotype: Chlorpyrifos, diazinon, dieldrin and divalent nickel

    SciTech Connect

    Slotkin, Theodore A. Seidler, Frederic J.

    2008-12-01

    Developmental exposure to organophosphates (OP) produces long-term changes in serotonin (5HT) synaptic function and associated behaviors, but there are disparities among the different OPs. We contrasted effects of chlorpyrifos and diazinon, as well as non-OP neurotoxicants (dieldrin, Ni{sup 2+}) using undifferentiated and differentiating PC12 cells, a well-established neurodevelopmental model. Agents were introduced at 30 {mu}M for 24 or 72 h, treatments devoid of cytotoxicity, and we evaluated the mRNAs encoding the proteins for 5HT biosynthesis, storage and degradation, as well as 5HT receptors. Chlorpyrifos and diazinon both induced tryptophan hydroxylase, the rate-limiting enzyme for 5HT biosynthesis, but chlorpyrifos had a greater effect, and both agents suppressed expression of 5HT transporter genes, effects that would tend to augment extracellular 5HT. However, whereas chlorpyrifos enhanced the expression of most 5HT receptor subtypes, diazinon evoked overall suppression. Dieldrin evoked even stronger induction of tryptophan hydroxylase, and displayed a pattern of receptor effects similar to that of diazinon, even though they come from different pesticide classes. In contrast, Ni{sup 2+} had completely distinct actions, suppressing tryptophan hydroxylase and enhancing the vesicular monoamine transporter, while also reducing 5HT receptor gene expression, effects that would tend to lower net 5HT function. Our findings provide some of the first evidence connecting the direct, initial mechanisms of developmental neurotoxicant action on specific transmitter pathways with their long-term effects on synaptic function and behavior, while also providing support for in vitro test systems as tools for establishing mechanisms and outcomes of related and unrelated neurotoxicants.

  2. CHARACTERIZATION OF RESIDENTIAL EXPOSURE TO CHLORPYRIFOS AND DIAZINON

    EPA Science Inventory

    Exposures to chlorpyrifos and diazinon in residential microenvironment in AZ were estimated using the indirect method of exposure calculation by combining measured concentrations in multiple media with time subjects spent indoors, dietary and non-dietary items they consumed, an...

  3. REGRESSION MODELS OF RESIDENTIAL EXPOSURE TO CHLORPYRIFOS AND DIAZINON

    EPA Science Inventory

    This study examines the ability of regression models to predict residential exposures to chlorpyrifos and diazinon, based on the information from the NHEXAS-AZ database. The robust method was used to generate "fill-in" values for samples that are below the detection l...

  4. The Reliability of Using Urinary Biomarkers to Estimate Human Exposures to Chlorpyrifos and Diazinon

    EPA Science Inventory

    A few studies have reported concurrent levels of chlorpyrifos (CPF) and diazinon (DZN) and their environmentally occurring metabolites, 3,5,6-trichloro-2-pyridinol (TCP) and 2-isopropyl-6-methyl-4-pyrimidinol (IMP), in food and in environmental media. This information raises ques...

  5. Diazinon and chlorpyrifos loads in the San Joaquin River basin, California, January and February 2000

    USGS Publications Warehouse

    Kratzer, Charles R.; Zamora, Celia; Knifong, Donna L.

    2002-01-01

    The application of diazinon and chlorpyrifos on dormant orchards in 2000 in the San Joaquin River Basin was less than 21 percent of application in 1993 and 1994. A total of 13 sites were sampled weekly during nonstorm periods and more frequently during two storm periods. The sites included five major river and eight minor tributary sites. The highest concentrations of diazinon and chlorpyrifos occurred during the storm periods. Four samples from major river sites (Tuolumne River and two San Joaquin River sites) had diazinon concentrations greater than 0.08 microgram per liter, the concentration being considered by the state of California as its criterion maximum concentration for the protection of aquatic habitat. One sample from a major river site (San Joaquin River) exceeded the equivalent State guideline of 0.02 microgram per liter for chlorpyrifos. At the eight minor tributary sites, 24 samples exceeded the diazinon guideline and four samples exceeded the chlorpyrifos guideline. The total diazinon load in the San Joaquin River near Vernalis during January and February 2000 was 19.6 pounds active ingredient; of this, 8.17 pounds active ingredient was transported during two storms. In 1994, 27.4 pounds active ingredient was transported during two storms. The total chlorpyrifos load in the San Joaquin River near Vernalis during January and February 2000 was 5.68 pounds active ingredient; of this, 2.17 pounds active ingredient was transported during the two storms. During the frequently sampled February 2000 storm, the main sources of diazinon in the San Joaquin River Basin were the San Joaquin River near Stevinson Basin (25 percent), Tuolumne River Basin (14 percent), and the Stanislaus River Basin (10 percent). The main sources of chlorpyrifos in the San Joaquin River Basin were the San Joaquin River near Stevinson Basin (17 percent), Tuolumne River Basin (13 percent), and the Merced River Basin (11 percent). The total January and February diazinon load in the

  6. Temporal changes in surface-water insecticide concentrations after the phaseout of diazinon and chlorpyrifos

    USGS Publications Warehouse

    Phillips, P.J.; Ator, S.W.; Nystrom, E.A.

    2007-01-01

    The recent (late 2001) federally mandated phaseout of diazinon and chlorpyrifos insecticide use in outdoor urban settings has resulted in a rapid decline in concentrations of these insecticides in urban streams and rivers in the northeastern and midwestern United States. Assessment of temporal insecticide trends at 20 sites showed that significant step decreases in diazinon concentrations occurred at 90% of the sites after the phaseout, with concentrations generally decreasing by over 50% in summer samples. Chlorpyrifos concentrations showed significant step decreases in at least 1 season at 3 of the 4 sites with sufficient data for analysis. The decrease in diazinon concentrations in response to the phaseout resulted in a decline in the frequency of concentrations exceeding the acute invertebrate water-quality benchmark of 0.1 ??g/L from 10% of pre-phaseout summer samples to fewer than 1% of post-phaseout summer samples. Although some studies have indicated an increase in concentrations of carbaryl in response to the organophosphorous phaseout, carbaryl concentrations only increased at 1 site after the phaseout. A full assessment of the effect of the phaseout of diazinon and chlorpyrifos on surface water will require data on other insecticides used to replace these compounds.

  7. Comparative toxicity of chlorpyrifos, diazinon, malathion and their oxon derivatives to larval Rana boylii.

    PubMed

    Sparling, D W; Fellers, G

    2007-06-01

    Organophosphorus pesticides (OPs) are ubiquitous in the environment and are highly toxic to amphibians. They deactivate cholinesterase, resulting in neurological dysfunction. Most chemicals in this group require oxidative desulfuration to achieve their greatest cholinesterase-inhibiting potencies. Oxon derivatives are formed within liver cells but also by bacterial decay of parental pesticides. This study examines the toxicity of chlorpyrifos, malathion and diazinon and their oxons on the foothill yellow-legged frog (Rana boylii). R. boylii is exposed to agricultural pesticides in the California Central Valley. Median lethal concentrations of the parental forms during a 96 h exposure were 3.00 mg/L (24h) for chlorpyrifos, 2.14 mg/L for malathion and 7.49 mg/L for diazinon. Corresponding oxons were 10 to 100 times more toxic than their parental forms. We conclude that environmental concentrations of these pesticides can be harmful to R. boylii populations.

  8. Differential acetylcholinesterase inhibition of chlorpyrifos, diazinon and parathion in larval zebrafish

    PubMed Central

    Yen, Jerry; Donerly, Sue; Levin, Edward D.; Linney, Elwood A.

    2011-01-01

    Zebrafish are increasingly used for developmental neurotoxicity testing because early embryonic events are easy to visualize, exposures are done without affecting the mother and the rapid development of zebrafish allows for high throughput testing. We used zebrafish to examine how exposures to three different organophosphorus pesticides (chlorpyrifos, diazinon and parathion) over the first five days of embryonic and larval development of zebrafish affected their survival, acetylcholinesterase (AChE) activity and behavior. We show that at non-lethal, equimolar concentrations, chlorpyrifos (CPF) is more effective at equimolar concentrations than diazinon (DZN) and parathion (PA) in producing AChE inhibition. As concentrations of DZN and PA are raised, lethality occurs before they can produce the degree of AChE inhibition observed with CPF at 300nM. Because of its availability outside the mother at the time of fertilization, zebrafish provides a complementary model for studying the neurotoxicity of very early developmental exposures. PMID:22036888

  9. Comparative toxicity of chlorpyrifos, diazinon, malathion and their oxon derivatives to larval Rana boylii

    USGS Publications Warehouse

    Sparling, D.W.; Fellers, G.

    2007-01-01

    Organophosphorus pesticides (OPs) are ubiquitous in the environment and are highly toxic to amphibians. They deactivate cholinesterase, resulting in neurological dysfunction. Most chemicals in this group require oxidative desulfuration to achieve their greatest cholinesterase-inhibiting potencies. Oxon derivatives are formed within liver cells but also by bacterial decay of parental pesticides. This study examines the toxicity of chlorpyrifos, malathion and diazinon and their oxons on the foothill yellow-legged frog (Rana boylii). R. boylii is exposed to agricultural pesticides in the California Central Valley. Median lethal concentrations of the parental forms during a 96 h exposure were 3.00 mg/L (24 h) for chlorpyrifos, 2.14 mg/L for malathion and 7.49 mg/L for diazinon. Corresponding oxons were 10 to 100 times more toxic than their parental forms. We conclude that environmental concentrations of these pesticides can be harmful to R. boylii populations. ?? 2006 Elsevier Ltd. All rights reserved.

  10. In-residence, multiple route exposures to chlorpyrifos and diazinon estimated by indirect method models

    NASA Astrophysics Data System (ADS)

    Moschandreas, D. J.; Kim, Y.; Karuchit, S.; Ari, H.; Lebowitz, M. D.; O'Rourke, M. K.; Gordon, S.; Robertson, G.

    One of the objectives of the National Human Exposure Assessment Survey (NHEXAS) is to estimate exposures to several pollutants in multiple media and determine their distributions for the population of Arizona. This paper presents modeling methods used to estimate exposure distributions of chlorpyrifos and diazinon in the residential microenvironment using the database generated in Arizona (NHEXAS-AZ). A four-stage probability sampling design was used for sample selection. Exposures to pesticides were estimated using the indirect method of exposure calculation by combining measured concentrations of the two pesticides in multiple media with questionnaire information such as time subjects spent indoors, dietary and non-dietary items they consumed, and areas they touched. Most distributions of in-residence exposure to chlorpyrifos and diazinon were log-normal or nearly log-normal. Exposures to chlorpyrifos and diazinon vary by pesticide and route as well as by various demographic characteristics of the subjects. Comparisons of exposure to pesticides were investigated among subgroups of demographic categories, including gender, age, minority status, education, family income, household dwelling type, year the dwelling was built, pesticide use, and carpeted areas within dwellings. Residents with large carpeted areas within their dwellings have higher exposures to both pesticides for all routes than those in less carpet-covered areas. Depending on the route, several other determinants of exposure to pesticides were identified, but a clear pattern could not be established regarding the exposure differences between several subpopulation groups.

  11. Cardiotoxicity in rabbits after a low-level exposure to diazinon, propoxur, and chlorpyrifos.

    PubMed

    Zafiropoulos, A; Tsarouhas, K; Tsitsimpikou, C; Fragkiadaki, P; Germanakis, I; Tsardi, M; Maravgakis, G; Goutzourelas, N; Vasilaki, F; Kouretas, D; Hayes, Aw; Tsatsakis, Am

    2014-12-01

    Lethal cardiac complications leading to death and various arrhythmias have been reported after organophosphate and/or carbamate poisonings. The present study focuses on the long-term effects of repeated low-level exposure to diazinon, propoxur, and chlorpyrifos (CPF) on cardiac function in rabbits. The yearly based experimental scheme of exposure consisted of two oral administration periods, lasting 3 months and 1 month each, interrupted by an 8-month washout period (total duration 12 months). At the end of the experimental scheme, the rabbits underwent an echocardiographic evaluation under sedation, after which they were killed and the tissue and serum samples were collected. A mild localized cardiotoxic effect was established by echocardiography for the three pesticides tested. Severe histological alterations were identified, especially in the diazinon-treated animals in agreement with increased persistence of this pesticide established in the cardiac tissue. In addition, all pesticides tested increased the oxidative stress and oxidative modifications in the genomic DNA content of the cardiac tissues, each one following a distinct mechanism.

  12. Cardiotoxicity in rabbits after a low-level exposure to diazinon, propoxur, and chlorpyrifos.

    PubMed

    Zafiropoulos, A; Tsarouhas, K; Tsitsimpikou, C; Fragkiadaki, P; Germanakis, I; Tsardi, M; Maravgakis, G; Goutzourelas, N; Vasilaki, F; Kouretas, D; Hayes, Aw; Tsatsakis, Am

    2014-12-01

    Lethal cardiac complications leading to death and various arrhythmias have been reported after organophosphate and/or carbamate poisonings. The present study focuses on the long-term effects of repeated low-level exposure to diazinon, propoxur, and chlorpyrifos (CPF) on cardiac function in rabbits. The yearly based experimental scheme of exposure consisted of two oral administration periods, lasting 3 months and 1 month each, interrupted by an 8-month washout period (total duration 12 months). At the end of the experimental scheme, the rabbits underwent an echocardiographic evaluation under sedation, after which they were killed and the tissue and serum samples were collected. A mild localized cardiotoxic effect was established by echocardiography for the three pesticides tested. Severe histological alterations were identified, especially in the diazinon-treated animals in agreement with increased persistence of this pesticide established in the cardiac tissue. In addition, all pesticides tested increased the oxidative stress and oxidative modifications in the genomic DNA content of the cardiac tissues, each one following a distinct mechanism. PMID:24818614

  13. Oxidative and Excitatory Mechanisms of Developmental Neurotoxicity: Transcriptional Profiles for Chlorpyrifos, Diazinon, Dieldrin, and Divalent Nickel in PC12 Cells

    PubMed Central

    Slotkin, Theodore A.; Seidler, Frederic J.

    2009-01-01

    Background Oxidative stress and excitotoxicity underlie the developmental neurotoxicity of numerous chemicals. Objectives We compared the effects of organophosphates (chlorpyrifos and diazinon), an organo-chlorine (dieldrin), and a metal [divalent nickel (Ni2+)] to determine how these mechanisms contribute to similar or dissimilar neurotoxic outcomes. Methods We used PC12 cells as a model of developing neurons and evaluated transcriptional profiles for genes for oxidative stress responses and glutamate receptors. Results Chlorpyrifos had a greater effect on oxidative-stress–related genes in differentiating cells compared with the undifferentiated state. Chlorpyrifos and diazinon showed significant concordance in their effects on glutathione-related genes, but they were negatively correlated for effects on catalase and superoxide dismutase isoforms and had no concordance for effects on ionotropic glutamate receptors. Surprisingly, the correlations were stronger between diazinon and dieldrin than between the two organophosphates. The effects of Ni2+ were the least similar for genes related to oxidative stress but had significant concordance with dieldrin for effects on glutamate receptors. Conclusions Our results point to underlying mechanisms by which different organophosphates produce disparate neurotoxic outcomes despite their shared property as cholinesterase inhibitors. Further, apparently unrelated neurotoxicants may produce similar outcomes because of convergence on oxidative stress and excitotoxicity. The combined use of cell cultures and microarrays points to specific end points that can distinguish similarities and disparities in the effects of diverse developmental neurotoxicants. PMID:19440498

  14. Screening for the Pesticides Atrazine, Chlorpyrifos, Diazinon, Metolachlor, and Simazine in Selected Michigan Streams, March-November 2005

    USGS Publications Warehouse

    Fogarty, Lisa R.; Duris, Joseph W.

    2007-01-01

    From March through November 2005, the U.S. Geological Survey, in cooperation with the Michigan Department of Environmental Quality (MDEQ), did a statewide screening to aid in understanding the occurrence and distribution of selected pesticides in Michigan streams. Stream-water samples were collected from 23 sites throughout Michigan. In all, 320 water samples were analyzed by use of rapid immunoassay methods for the herbicides atrazine, metolachlor, and simazine and the insecticides chlorpyrifos and diazinon. On one occasion (June, 2005), atrazine concentrations exceeded the Michigan water-quality value (7.3 micrograms per liter) at the Black River in St. Clair County. Neither chlorpyrifos nor diazinon was detected during April through September. MDEQ detected chlorpyrifos in streams throughout the state in November. Herbicide concentrations were highest in samples influenced by intensive agriculture; however, median herbicide concentrations were similar among agricultural and urban sites. Concentrations of herbicides were very low to undetected in undeveloped areas. Seasonal patterns were also evident during the sampling period. Increased concentrations generally occurred in late spring to early summer. At 11 sites, daily sampling was done every day for 5 days following a rainfall after herbicide application in the area. Substantial changes in concentrations of herbicides - greater than tenfold from the previous day - were observed during the daily sampling. No consistent relation was found between concentration and streamflow. Results of this study may be used to aid in the development of a more comprehensive pesticide monitoring study for the State of Michigan.

  15. PHARMACOKINETIC AND PHARMACODYNAMIC INTERACTION FOR A BINARY MIXTURE OF CHLORPYRIFOS AND DIAZINON IN THE RAT

    SciTech Connect

    Timchalk, Chuck; Poet, Torka S.; Hinman, Melissa N.; Busby, Andrea L.; Kousba, Ahmed A.

    2005-05-15

    Chlorpyrifos (CPF) and diazinon (DZN) are two commonly used organophosphorus (OP) insecticides and potential exists for concurrent exposures. The primary neurotoxic effects from OP pesticide exposures result from the inhibition of acetylcholinesterase (AChE) by their oxon metabolites. The pharmacokinetic and pharmacodynamic impact of acute binary exposures to CPF and DZN in rats were evaluated in this study. Rats were orally administered CPF, DZN or a CPF/DZN mixture (0, 15, 30 or 60 mg/kg) and blood (plasma and RBC), and brain were collected at 0, 3, 6, 12 and 24 h post-dosing, urine was also collected at 24 h. Chlorpyrifos, DZN and their respective metabolites 3,5,6-trichloro-2-pyridinol (TCP) and 2-isopropyl-4-methyl-6-hydroxypyrimidine (IMHP) were quantified in blood and/or urine and cholinesterase (ChE) inhibition was measured in brain, RBCs and plasma. Co-exposure to CPF/DZN at 15/15 mg/kg, did not appreciably alter the pharmacokinetics of CPF, DZN or their metabolites in blood; whereas, a 60/60 mg/kg dose resulted in a transient increase in Cmax, AUC, and decreased clearance of both compounds, likely due to competition between CPF and DZN for CYP450 metabolism. At lower doses, most likely to be encountered in occupational or environmental exposures, the pharmacokinetics were linear. A dose-dependent inhibition of ChE was noted in tissues for both the single and co-exposures. The overall potency for ChE inhibition was greater for CPF than DZN and the binary mixture response appeared to be strongly influenced by CPF. A comparison of the ChE binary response at the low dose (15 mg/kg), where there were no apparent pharmacokinetic interactions, suggested that the overall ChE response was additive. These are the first reported experiments we are aware of that characterize both the pharmacokinetic and pharmacodynamic interactions between CPF and DZN in the rat, and will be used to further develop a binary physiologically based pharmacokinetic and pharmacodynamic

  16. In Vitro Rat Hepatic and Intestinal Metabolism of the Organophosphate Pesticides Chlorpyrifos and Diazinon

    SciTech Connect

    Poet, Torka S. ); Wu, Hong ); Kousba, Ahmed A. ); Timchalk, Charles

    2003-04-01

    Chlorpyrifos (CPF) and diazinon (DZN) are thionophosphorus organophosphate, insecticides; their toxicity is mediated through CYP450 metabolism to CPF-oxon and DZN-oxon, respectively. Conversely, CYP450s also detoxify these OPs to trichloropyridinol (TCP) and 2-isopropyl-4-methyl-6-hydroxypyrimidine (IMHP), respectively. In addition, A-esterase metabolism of CPF- and DZN-oxon also form TCP and IMHP. This study evaluated the role intestinal and hepatic metabolism may play in the first-pass elimination of CPF and DZN. Similar CYP450- and A-esterase-mediated metabolic profiles were demonstrated in microsomes from liver or isolated intestinal enterocytes. In enterocyte microsomes, the CYP450 metabolic efficiency (Vmax/Km) for metabolism to the oxon metabolites was~5-fold greater for CPF than DZN. Compared on a per nmol P450 basis, the Vmax for CPF in enterocytes was~2-3 times higher than in liver microsomes for the production of CPF-oxon and TCP. The affinity (Km) for the metabolism of CPF to CPF-oxon was comparable in liver and enterocyte microsomes, however the enterocyte Km for TCP production was higher (lower affinity). The smaller volume of intestine, lower amount of CYP450, and higher Km for TCP in the enterocyte microsomes, resulted in a lower catalytic efficiency (2 and 62 times) than in liver for oxon and TCP. A-esterase-mediated metabolism of CPF- and DZN-oxon was also demonstrated in liver and enterocyte microsomes. Although A-esterase affinity for the substrates were comparable in hepatic and enterocyte microsomes, the Vmax were 48 - to 275-fold, in the liver. These results suggest that intestinal metabolism may impact first-pass metabolism of CPF and DZN, especially following low-dose oral exposures.

  17. AGE-RELATED BRAIN CHOLINESTERASE INHIBITION KINETICS FOLLOWING IN VITRO INCUBATION WITH CHLORPYRIFOS-OXON AND DIAZINON-OXON

    SciTech Connect

    Kousba, Ahmed A.; Poet, Torka S.; Timchalk, Chuck

    2007-01-01

    Chlorpyrifos and diazinon are two commonly used organophosphorus (OP) insecticides, and their primary mechanism of action involves the inhibition of acetylcholinesterase (AChE) by their metabolites chlorpyrifos-oxon (CPO) and diazinon-oxon (DZO), respectively. The study objectives were to assess the in vitro age-related inhibition kinetics of neonatal rat brain cholinesterase (ChE) by estimating the bimolecular inhibitory rate constant (ki) values for CPO and DZO. Brain ChE inhibition and ki values following CPO and DZO incubation with neonatal Sprague-Dawley rats rat brain homogenates were determined at post natal day (PND) -5, -12 and -17 and compared with the corresponding inhibition and ki values obtained in the adult rat. A modified Ellman method was utilized for measuring the ChE activity. Chlorpyrifos-oxon resulted in greater ChE inhibition than DZO consistent with the estimated ki values of both compounds. Neonatal brain ChE inhibition kinetics exhibited a marked age-related sensitivity to CPO, where the order of ChE inhibition was PND-5 > PND-7 > PND-17 with ki values of 0.95, 0.50 and 0.22 nM-1hr-1, respectively. In contrast, DZO did not exhibit an age-related inhibition of neonatal brain ChE, and the estimated ki value at all PND ages was 0.02 nM-1hr-1. These results demonstrated an age- and chemical-related OP-selective inhibition of rat brain ChE which may be critically important in understanding the potential sensitivity of juvenile humans to specific OP exposures.

  18. Evaluation of Diazinon and Chlorpyrifos Concentrations and Loads, and other Pesticide Concentrations, at Selected Sites in the San Joaquin Valley, California, April to August, 2001

    USGS Publications Warehouse

    Domagalski, Joseph L.; Munday, Cathy

    2003-01-01

    Twelve sites in the San Joaquin Valley of California were monitored weekly during the growing and irrigation season of 2001 for a total of 51 pesticides and pesticide degradation products, with primary interest on the concentration, load, and basin yield of organophosphorus insecticides, especially diazinon and chlorpyrifos. Diazinon was detected frequently, up to 100 percent of the time, at many of the sampling sites, but with generally low concentrations. For all sites, 75 percent of all measured diazinon concentrations were less than 0.02 mg/L, and 90 percent of all measured diazinon concentrations were less than 0.06 mg/L. The highest diazinon concentrations were measured in samples from two west-side tributaries to the San Joaquin River, Orestimba Creek, and Del Puerto Creek. The median concentration of chlorpyrifos was at or less than the laboratory reporting limit (0.005 mg/L) for most sites with the exceptions of two tributaries to the San Joaquin River: Orestimba Creek and the Tuolumne River. For all sites, 75 percent of all measured chlorpyrifos concentrations were less than 0.03 mg/L and 90 percent of all measured chlorpyrifos concentrations were less than 0.07 mg/L. The total load of diazinon out of the basin was just over 7 kilograms, which accounted for about 0.17 percent of the total agricultural applications. The diazinon load from the monitored upstream tributaries accounted for about 50 percent of the load at the mouth of the San Joaquin River. The streamflow from the selected monitored tributaries accounted for about 83 percent of the streamflow at the mouth of the San Joaquin River. The total load of chlorpyrifos out of the basin was 3.75 kilograms, and this accounted for approximately 0.007 percent of the total amount applied. Other pesticides that were frequently detected during this study included herbicides such as metolachlor, simazine, and trifluralin, and insecticides such as carbaryl, carbofuran, and propargite. At Orestimba Creek, DDE

  19. Low-level repeated exposure to diazinon and chlorpyrifos decrease anxiety-like behaviour in adult male rats as assessed by marble burying behaviour.

    PubMed

    Savy, Claire Y; Fitchett, Ann E; McQuade, Richard; Gartside, Sarah E; Morris, Christopher M; Blain, Peter G; Judge, Sarah J

    2015-09-01

    Occupational exposure to organophosphate (OPs) pesticides is reported to increase in the risk of developing anxiety and depression. Preclinical studies using OP levels, which inhibit acetylcholinesterase activity, support the clinical observations, but little is known of the effects of exposure below this threshold. We examined the effects of low level OP exposure on behaviours and neurochemistry associated with affective disorders. Adult rats were administered either diazinon (1 mg/kg i.p.) which is present in sheep dip and flea collars, chlorpyrifos (1 mg/kg i.p.) which is present in crop sprays, or vehicle for 5 days. OP exposure did not affect acetylcholinesterase activity (blood, cerebellum, caudate putamen, hippocampus, prefrontal cortex), anhedonia-like behaviour (sucrose preference), working memory (novel object recognition), locomotor activity or anxiety-like behaviour in the open field arena. In contrast OP exposure attenuated marble burying behaviour, an ethological measure of anxiety. The diazinon-induced reduction in marble burying persisted after exposure cessation. In comparison to vehicle, dopamine levels were lowered by chlorpyrifos, but not diazinon. 5-HT levels and turnover were unaffected by OP exposure. However, 5-HT transporter expression was reduced by diazinon suggesting subtle changes in 5-HT transmission. These data indicate exposure to occupational and domestic OPs, below the threshold to inhibit acetylcholinesterase, can subtly alter behaviour and neurochemistry.

  20. The In Vivo Quantitation of Diazinon, Chlorpyrifos and their Major Metabolites in Rat Blood for the Refinement of a Physiologically-based Pharmacokinetic/pharmacodynamic Models.

    SciTech Connect

    Busby, Andrea L.; Kousba, Ahmed A.; Timchalk, Chuck

    2004-12-01

    Chlorpyrifos (CPF) and diazinon (DZN) are inhibitors of acetylcholinesterase due to the effects of their active oxon metabolites. The inhibition of acetylcholinesterase results in a buildup of acetylcholine within the nerve synapses leading to a variety of neurotoxic effects (Mileson et al., 1998). These effects are most clearly seen following acute high dose exposures but they can also be observed in lower dose chronic cases as well. Chlorpyrifos is the active ingredient in commonly used organophosphorous (OP) insecticides like DURSBAN and LORSBAN (Timchalk et. al, 2002). Chlorpyrifos and diazinon are used to eliminate pests in agricultural applications like cotton and fruit crops. Every year globally there are approximately 3 million cases of organophosphate poisoning reported resulting in 200,000 deaths (Haywood et al., 2000). The public is exposed to these chemicals on a regular basis at chronic low levels from food and water contamination, dermal contact and inhalation. The United States National Health and Nutrition Examination Survey indicated that of approximately 3,600 persons from all 64 NHANES III locations, 70% tested positive for TCP in urine, suggesting exposure to chlorpyrifos (NHANES III, 1994). The chemical structures of chlorpyrifos, diazinon, and their major metabolites trichlorpyridinol (TCP), and isopropyl-methyl-hydroxypyrimidine (IMHP) are shown in Figure 1. The parent compounds, CPF and DZN, are metabolized to their potent inhibiting oxon forms via a desulfuration reaction initiated by cytochrome P450 (CYP)(Poet et al., 2003; Amitai et al., 1998). Competing with the formation of oxon is the detoxification metabolism of CPF to TCP and DZN to IMHP via a dearylation reaction utilizing the same enzymes. A-esterase (PON1) and other B-esterases also contribute to the production of TCP and IMHP through the metabolism of CPF-oxon and DZN-oxon, respectively (Poet et al., 2003; Ma et al., 1994). The ratio between the toxification

  1. Diazinon and chlorpyrifos loads in precipitation and urban and agricultural storm runoff during January and February 2001 in the San Joaquin River basin, California

    USGS Publications Warehouse

    Zamora, Celia; Kratzer, Charles R.; Majewski, Michael S.; Knifong, Donna L.

    2003-01-01

    The application of diazinon and chlorpyrifos on dormant orchards in 2001 in the San Joaquin River Basin was 24 percent less and 3.2 times more than applications in 2000, respectively. A total of 16 sites were sampled during January and February 2001 storm events: 7 river sites, 8 precipitation sites, and 1 urban storm drain. The seven river sites were sampled weekly during nonstorm periods and more frequently during storm runoff from a total of four storms. The monitoring of storm runoff at a city storm drain in Modesto, California, occurred simultaneously with the collection of precipitation samples from eight sites during a January 2001 storm event. The highest concentrations of diazinon occurred during the storm periods for all 16 sites, and the highest concentrations of chlorpyrifos occurred during weekly nonstorm sampling for the river sites and during the January storm period for the urban storm drain and precipitation sites. A total of 60 samples (41 from river sites, 10 from precipitation sites, and 9 from the storm drain site) had diazinon concentrations greater than 0.08 ?g/L, the concentration being considered by the California Department of Fish and Game as its criterion maximum concentration for the protection of aquatic habitats. A total of 18 samples (2 from river sites, 9 from precipitation sites, and 7 from the storm drain site) exceeded the equivalent California Department of Fish and Game guideline of 0.02 ?g/L for chlorpyrifos. The total diazinon load in the San Joaquin River near Vernalis during January and February 2001 was 23.8 pounds active ingredient; of this amount, 16.9 pounds active ingredient were transported by four storms, 1.06 pounds active ingredient were transported by nonstorm events, and 5.82 pounds active ingredient were considered to be baseline loads. The total chlorpyrifos load in the San Joaquin River near Vernalis during January and February 2001 was 2.17 pounds active ingredient; of this amount, 0.702 pound active

  2. Organophosphorus insecticides chlorpyrifos and diazinon and oxidative stress in neuronal cells in a genetic model of glutathione deficiency.

    PubMed

    Giordano, Gennaro; Afsharinejad, Zhara; Guizzetti, Marina; Vitalone, Annabella; Kavanagh, Terrance J; Costa, Lucio G

    2007-03-01

    Over the past several years evidence has been accumulating from in vivo animal studies, observations in humans, and in vitro studies, that organophosphorus (OP) insecticides may induce oxidative stress. Such effects may contribute to some of the toxic manifestations of OPs, particularly upon chronic or developmental exposures. The aim of this study was to investigate the role of oxidative stress in the neurotoxicity of two commonly used OPs, chlorpyrifos (CPF) and diazinon (DZ), their oxygen analogs (CPO and DZO), and their "inactive" metabolites (TCP and IMP), in neuronal cells from a genetic model of glutathione deficiency. Cerebellar granule neurons from wild type mice (Gclm +/+) and mice lacking the modifier subunit of glutamate cysteine ligase (Gclm -/-), the first and limiting step in the synthesis of glutathione (GSH), were utilized. The latter display very low levels of GSH and are more susceptible to the toxicity of agents that increase oxidative stress. CPO and DZO were the most cytotoxic compounds, followed by CPF and DZ, while TCP and IMP displayed lower toxicity. Toxicity was significantly higher (10- to 25-fold) in neurons from Gclm (-/-) mice, and was antagonized by various antioxidants. Depletion of GSH from Gclm (+/+) neurons significantly increased their sensitivity to OP toxicity. OPs increased intracellular levels of reactive oxygen species and lipid peroxidation and in both cases the effects were greater in neurons from Gclm (-/-) mice. OPs did not alter intracellular levels of GSH, but significantly increased those of oxidized glutathione (GSSG). Cytotoxicity was not antagonized by cholinergic antagonists, but was decreased by the calcium chelator BAPTA-AM. These studies indicate that cytotoxicity of OPs involves generation of reactive oxygen species and is modulated by intracellular GSH, and suggest that it may involve disturbances in intracellular homeostasis of calcium.

  3. Organophosphorus insecticides chlorpyrifos and diazinon and oxidative stress in neuronal cells in a genetic model of glutathione deficiency

    SciTech Connect

    Giordano, Gennaro; Afsharinejad, Zhara; Guizzetti, Marina; Vitalone, Annabella; Kavanagh, Terrance J.; Costa, Lucio G. . E-mail: lgcosta@u.washington.edu

    2007-03-15

    Over the past several years evidence has been accumulating from in vivo animal studies, observations in humans, and in vitro studies, that organophosphorus (OP) insecticides may induce oxidative stress. Such effects may contribute to some of the toxic manifestations of OPs, particularly upon chronic or developmental exposures. The aim of this study was to investigate the role of oxidative stress in the neurotoxicity of two commonly used OPs, chlorpyrifos (CPF) and diazinon (DZ), their oxygen analogs (CPO and DZO), and their 'inactive' metabolites (TCP and IMP), in neuronal cells from a genetic model of glutathione deficiency. Cerebellar granule neurons from wild type mice (Gclm +/+) and mice lacking the modifier subunit of glutamate cysteine ligase (Gclm -/-), the first and limiting step in the synthesis of glutathione (GSH), were utilized. The latter display very low levels of GSH and are more susceptible to the toxicity of agents that increase oxidative stress. CPO and DZO were the most cytotoxic compounds, followed by CPF and DZ, while TCP and IMP displayed lower toxicity. Toxicity was significantly higher (10- to 25-fold) in neurons from Gclm (-/-) mice, and was antagonized by various antioxidants. Depletion of GSH from Gclm (+/+) neurons significantly increased their sensitivity to OP toxicity. OPs increased intracellular levels of reactive oxygen species and lipid peroxidation and in both cases the effects were greater in neurons from Gclm (-/-) mice. OPs did not alter intracellular levels of GSH, but significantly increased those of oxidized glutathione (GSSG). Cytotoxicity was not antagonized by cholinergic antagonists, but was decreased by the calcium chelator BAPTA-AM. These studies indicate that cytotoxicity of OPs involves generation of reactive oxygen species and is modulated by intracellular GSH, and suggest that it may involve disturbances in intracellular homeostasis of calcium.

  4. Spatial distribution and temporal trend in concentration of carbofuran, diazinon and chlorpyrifos ethyl residues in sediment and water in Lake Naivasha, Kenya.

    PubMed

    Otieno, Peter O; Schramm, Karl-Werner; Pfister, Gerd; Lalah, Joseph O; Ojwach, Stephen O; Virani, Munir

    2012-04-01

    Chlorpyrifos ethyl was found to be widely distributed in water and sediment in Lake Naivasha. Higher levels were reported in sediment (11.2-30.0 ng g(-1) dry weight (dw) in wet season than in dry season (4.7-17.4 ng g(-1) dw). The mean concentration of chlorpyrifos ethyl in water in wet season ranged between 8.8 and 26.6 μg L(-1) and decreased to between below detection limit to 14.0 μg L(-1) in dry season. On average, higher concentrations of chlorpyrifos ethyl were observed in sediment than water samples. Statistical analysis revealed a significant difference in concentration between the seasons, and a significant interaction between seasons and mean concentrations at p ≤ 0.05. However, levels of diazinon and carbofuran were below the detection limit in all the samples analyzed. Notably, levels of chlorpyrifos ethyl were higher than the maximum allowable limits (0.1 μg L(-1)) recommended by European Union for drinking water and general water quality criterion for protection of freshwater water organisms (0.083 μg L(-1)).

  5. Chlorpyrifos

    Integrated Risk Information System (IRIS)

    Chlorpyrifos ; CASRN 2921 - 88 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  6. The In Vivo Quantitation of Diazinon, chlorpyrifos, and Their Major Metabolites in Rat Blood for the Refinement of a Physiologically-Based Pharmacokinetic/Pharmacodynamic Models

    SciTech Connect

    Busby, A.; Kousba, A.; Timchalk, C.

    2004-01-01

    Chlorpyrifos (CPF)(O,O-diethyl-O-[3,5,6-trichloro-2-pyridyl]-phosphorothioate, CAS 2921-88-2), and diazinon (DZN)(O,O-diethyl-O-2-isopropyl-4-methyl-6-pyrimidyl thiophosphate, CAS 333-41-5) are commonly encountered organophosphorus insecticides whose oxon metabolites (CPF-oxon and DZN-oxon) have the ability to strongly inhibit acetylcholinesterase, an enzyme responsible for the breakdown of acetylcholine at nerve synapses. Chlorpyrifos-oxon and DZN-oxon are highly unstable compounds that degrade via hepatic, peripheral blood, and intestinal metabolism to the more stable metabolites, TCP (3,5,6-trichloro-2-pyridinol, CAS not assigned) and IMHP (2-isopropyl-6-methyl-4-pyrimidinol, CAS 2814-20-2), respectively. Studies have been performed to understand and model the chronic and acute toxic effects of CPF and DZN individually but little is known about their combined effects. The purpose of this study was to improve physiologically based pharmacokinetic/ pharmacodynamic (PBPK/PD) computational models by quantifying concentrations of CPF and DZN and their metabolites TCP and IMHP in whole rat blood, following exposure to the chemicals individually or as a mixture. Male Sprague-Dawley rats were orally dosed with 60 mg/kg of CPF, DZN, or a mixture of these two pesticides. When administered individually DZN and CPF were seen to reach their maximum concentration at ~3 hours post-dosing. When given as a mixture, both DZN and CPF peak blood concentrations were not achieved until ~6 hours post-dosing and the calculated blood area under the curve (AUC) for both chemicals exceeded those calculated following the single dose. Blood concentrations of IMHP and TCP correlated with these findings. It is proposed that the higher AUC obtained for both CPF and DZN as a mixture resulted from competition for the same metabolic enzyme systems.

  7. Development of a Physiologically Based Pharmacokinetic and Pharmacodynamic Model to Determine Dosimetry and Cholinesterase Inhibition for a Binary Mixture of Chlorpyrifos and Diazinon in the Rat

    SciTech Connect

    Timchalk, Chuck; Poet, Torka S.

    2008-05-01

    Physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) models have been developed and validated for the organophosphorus (OP) insecticides chlorpyrifos (CPF) and diazinon (DZN). Based on similar pharmacokinetic and mode of action properties it is anticipated that these OPs could interact at a number of important metabolic steps including: CYP450 mediated activation/detoxification, and blood/tissue cholinesterase (ChE) binding/inhibition. We developed a binary PBPK/PD model for CPF, DZN and their metabolites based on previously published models for the individual insecticides. The metabolic interactions (CYP450) between CPF and DZN were evaluated in vitro and suggests that CPF is more substantially metabolized to its oxon metabolite than is DZN. These data are consistent with their observed in vivo relative potency (CPF>DZN). Each insecticide inhibited the other’s in vitro metabolism in a concentration-dependent manner. The PBPK model code used to described the metabolism of CPF and DZN was modified to reflect the type of inhibition kinetics (i.e. competitive vs. non-competitive). The binary model was then evaluated against previously published rodent dosimetry and ChE inhibition data for the mixture. The PBPK/PD model simulations of the acute oral exposure to single- (15 mg/kg) vs. binary-mixtures (15+15 mg/kg) of CFP and DZN at this lower dose resulted in no differences in the predicted pharmacokinetics of either the parent OPs or their respective metabolites; whereas, a binary oral dose of CPF+DZN at 60+60 mg/kg did result in observable changes in the DZN pharmacokinetics. Cmax was more reasonably fit by modifying the absorption parameters. It is anticipated that at low environmentally relevant binary doses, most likely to be encountered in occupational or environmental related exposures, that the pharmacokinetics are expected to be linear, and ChE inhibition dose-additive.

  8. Exposures of preschool children to chlorpyrifos, diazinon, pentachlorophenol, and 2,4-dichlorophenoxyacetic acid over 3 years from 2003 to 2005: A longitudinal model.

    PubMed

    Wilson, Nancy K; Strauss, Warren J; Iroz-Elardo, Nicole; Chuang, Jane C

    2010-09-01

    The impact of the US EPA-required phase-outs starting in 2000-2001 of residential uses of the organophosphate (OP) pesticides chlorpyrifos (CPF) and diazinon (DZN) on preschool children's pesticide exposures was investigated over 2003-2005, in the Raleigh-Durham-Chapel Hill area of North Carolina. Data were collected from 50 homes, each with a child initially of age 3 years (OCh) and a younger child (YCh). Environmental samples (indoor and outdoor air, dust, soil) and child-specific samples (hand surface residue, urine, diet) were collected annually over 24-h periods at each home. Child time-activity diaries and household pesticide use information were also collected. Analytes included CPF and DZN; pentachlorophenol (PCP); 2,4-dichlorophenoxyacetic acid (2,4-D); the CPF metabolite 3,5,6-trichloro-2-pyridinol (TCP); and the DZN metabolite 2-isopropyl-6-methyl-4-pyrimidinol (IMP). Exposures (ng/day) through the inhalation, dietary ingestion, and indirect ingestion were calculated. Aggregate potential doses in ng/kg body weight per day (ng/kg/day) were obtained by summing the potential doses through the three routes of exposure. Geometric mean aggregate potential doses decreased from 2003 to 2005 for both OCh and YCh, with the exception of 2,4-D. Child-specific longitudinal modeling indicated significant declines across time of the potential doses of CPF, DZN, and PCP for both children; declines of IMP for both children, significant only for OCh; a decline of TCP for OCh but an increase of TCP for YCh; and no significant change of 2,4-D for either child. Age-adjusted modeling indicated significant effects of the child's age for all except CPF, and of time for all except PCP and 2,4-D. Within-home variability was small compared with that between homes; variability was smallest for 2,4-D, both within and between homes. The aggregate potential doses of CPF and DZN were well below published reference dose values. These findings show the success of the US EPA restrictions

  9. Diazinon poisoning

    MedlinePlus

    Bazinon poisoning; Diazol poisoning; Gardentox poisoning; Knox-Out poisoning; Spectracide poisoning ... Below are symptoms of diazinon poisoning in different parts of the ... No breathing Bladder and kidneys: Increased urination Eyes, ...

  10. Influence of gender on thermoregulation and cholinesterase inhibition in the long-evans rat exposed to diazinon.

    PubMed

    Gordon, Christopher J; Mack, Cina M

    2003-02-14

    Diazinon is an organophosphate (OP)-based, anticholinesterase insecticide that irreversibly inhibits acetylcholinesterase activity and produces cholinergic stimulation in central nervous system (CNS) and peripheral tissues. Our laboratory has found that OPs administered orally in rats induce a transient period of hypothermia followed by a delayed fever that persists for several days after exposure. There is little information on the thermoregulatory effects of diazinon. Core temperature (Tc) and motor activity (MA) were monitored by radiotelemetry in male and female rats of the Long-Evans strain dosed orally with diazinon (0 [corn-oil vehicle], 100, 200, or 300 mg/kg in males and 0, 50, 100, or 200 mg/kg in females). There was a dose-dependent decrease in Tc during the first night after treatment, with females exhibiting slightly greater sensitivity than males. MA was unaffected in females exposed to diazinon at doses of 50 to 200 mg/kg; MA of males was reduced during the first night after dosing with 300 mg/kg. There was a delayed elevation in Tc of males dosed with 200 and 300 mg/kg and females dosed with 50, 100, and 200 mg/kg diazinon. The elevated Tc was only manifested during d 2 and 3 after diazinon. Administration of 200 mg/kg sodium salicylate to females 48 h after being treated with 200 mg/kg diazinon led to a rapid abatement of the fever. Diazinon doses of 50 to 300 mg/kg led to 40% to 50% inhibition in plasma cholinesterase (ChE) activity 4 h after dosing, and females displayed a significantly slower recovery of ChE activity compared to males. When compared on a molar basis, the hypothermic response to diazinon was relatively small compared to other OPs such as chlorpyrifos. The delayed fever and efficacy of sodium salicylate to block diazinon-induced fever are similar to the effects of OPs chlorpyrifos and diisopropyl fluoro-phosphate (DFP). PMID:12521673

  11. Evaluation of Residual Diazinon and Chlorpiryfos in Children Herbal Medicines by Headspace-SPME and GC-FID

    PubMed Central

    Mosaddegh, Mohammad Hossein; Emami, Fakhrossadat; Asghari, Gholamreza

    2014-01-01

    The oldest method for the managing of the illness is the use of medicinal plants. The use of herbal products as the first choice in self-treatment of minor conditions continues to expand rapidly across Iran. This makes the safety of herbal products an important public health issue. Pesticides are used widely in agriculture to increase the production by controlling the harmful insects and disease vectors, however it has some hazards on biological system of human especially children. The present study was designed to examine the residual amount of organophosphorus pesticides (Diazinon and Chlorpyrifos) in children herbal medicines available in the Iranian market. Five children herbal medicine liquid dosage forms were purchased from pharmacy store. They were extracted with SPME (Solid Phase Microextraction) using the PDMS-DVB fibre. Then the extracts were injected into a GC. The gas chromatograph was Younglin model YL 6100 equipped with a flame ionization detector. The column was Technokroma 60 m length, 0.53 mm internal diameter and 1.25 µm film coated. The presence and quantity of Diazinon and Chlorpyrifos were evaluated using their standard curves. Trace amounts of chlorpyrifos and diazinon were detected in a few herbal medicines. Based on European pharmacopeia, threshold limits of chlorpyrifos and diazinon residues for medicinal plant materials are 0.2 and 0.5 mg/Kg, respectively. Our analysis results showed that residue limits of these two pesticides in five children herbal medicines are ignorable. PMID:25237349

  12. Biodegradation of Chlorpyrifos by Enterobacter Strain B-14 and Its Use in Bioremediation of Contaminated Soils

    PubMed Central

    Singh, Brajesh K.; Walker, Allan; Morgan, J. Alun W.; Wright, Denis J.

    2004-01-01

    Six chlorpyrifos-degrading bacteria were isolated from an Australian soil and compared by biochemical and molecular methods. The isolates were indistinguishable, and one (strain B-14) was selected for further analysis. This strain showed greatest similarity to members of the order Enterobacteriales and was closest to members of the Enterobacter asburiae group. The ability of the strain to mineralize chlorpyrifos was investigated under different culture conditions, and the strain utilized chlorpyrifos as the sole source of carbon and phosphorus. Studies with ring or uniformly labeled [14C]chlorpyrifos in liquid culture demonstrated that the isolate hydrolyzed chlorpyrifos to diethylthiophospshate (DETP) and 3, 5, 6-trichloro-2-pyridinol, and utilized DETP for growth and energy. The isolate was found to possess mono- and diphosphatase activities along with a phosphotriesterase activity. Addition of other sources of carbon (glucose and succinate) resulted in slowing down of the initial rate of degradation of chlorpyrifos. The isolate degraded the DETP-containing organophosphates parathion, diazinon, coumaphos, and isazofos when provided as the sole source of carbon and phosphorus, but not fenamiphos, fonofos, ethoprop, and cadusafos, which have different side chains. Studies of the molecular basis of degradation suggested that the degrading ability could be polygenic and chromosome based. Further studies revealed that the strain possessed a novel phosphotriesterase enzyme system, as the gene coding for this enzyme had a different sequence from the widely studied organophosphate-degrading gene (opd). The addition of strain B-14 (106 cells g−1) to soil with a low indigenous population of chlorpyrifos-degrading bacteria treated with 35 mg of chlorpyrifos kg−1 resulted in a higher degradation rate than was observed in noninoculated soils. These results highlight the potential of this bacterium to be used in the cleanup of contaminated pesticide waste in the

  13. Diazinon-chemistry and environmental fate: a California perspective.

    PubMed

    Aggarwal, Vaneet; Deng, Xin; Tuli, Atac; Goh, Kean S

    2013-01-01

    Diazinon, first introduced in USA in 1956, is a broad-spectrum contact organophosphate pesticide that has been used as an insecticide, and nematicide. It has been ond of the most widely used insecticides in the USA for household and agricultural pest control. In 2004, residential use of diazinon was discontinued; as a result, the total amount applied has drastically decreased. [corrected]. Consequently, the amounts of diazinon applied have been drastically decreased. For example, in California, the amount of diazinon applied decreased from 501,784 kg in 2000 to 64,122 kg in 2010. Diazinon has a K(oc) value of 40-432 and is considered to be moderately mobile in soils. Diazinon residues have been detected in groundwater, drinking water wells, monitoring wells, and agricultural well. The highest detection frequencies and highest percentages of exceedance of the water quality criterion value of 0.1 μg/L have been reported from the top five agricultural counties n California that had the highest diazinon use. Diazinon is transported in air via atmospheric processes such as direct air movement and wet deposition in snow and rain, although concentrations decrease with distance and evaluation from the source. In the environment, diazinon undergoes degradation by several processes, the most important of which is microbial degradation in soils. The rate of diazinon degradation is affected by pH, soil type, organic amendments, soil moisture, and the concentration of diazinon in the soil, with soil pH being a major influencing factor in diazinon degradation rate. Studies indicate tha soil organic matter is the most important factor that influences diazinon sorption by soils, although clay content and soil ph also play an important role in diazinon sorption. Diazinon is very highly to moderately toxic aquatic arganisms, Diazinon inhibits the enzyme acetylcholinesterase, which hydrolyzes the neurotransmitter acetylcholine and leads to a suite of intermediate syndromes including

  14. Occurrence and transport of diazinon in the Sacramento River, California, and selected tributaries during three winter storms, January-February 2000

    USGS Publications Warehouse

    Dileanis, Peter D.; Bennett, Kevin P.; Domagalski, Joseph L.

    2002-01-01

    individual subbasins in the watershed. Concentrations of diazinon in 138 samples analyzed by gas chromatography methods ranged from below detection (2 ng/L) to 2,890 ng/L with a median of 44 ng/L. Thirty percent of the samples had concentrations greater than 80 ng/L, which is considered by California as the criterion maximum concentration for the protection of aquatic habitat. Concentrations were highest in small tributaries and canals draining subbasins with predominantly agricultural land use and in a channel draining the Yuba City urban area. Load estimates using concentrations derived from GC/MS analyses indicate that about 30 percent of the diazinon in the lower Sacramento River is from the Feather River Basin. Loads estimated using ELISA analyses show a similar, but slightly higher fraction of the total load coming from that basin. The source of over half the total load measured at Sacramento River at Alamar appears to have originated in the part of the drainage basin upstream of the city of Colusa. Of the diazinon reported applied to agricultural land in Sacramento Valley (about 42,500 pounds active ingredient) just before and during the monitoring period, about 0.4 percent appeared to be transported to the lower Sacramento River during the period of monitoring. A similar percent of applied diazinon was estimated to have entered the Feather River from upstream sources. Diazinon use in the study area during the 1999-2000 dormant spray season was unusually low, about 60 percent of the average of the previous 4 years. Therefore, diazinon loadings may be higher in subsequent years, should use increase and pesticide management practices remain the same. Although diazinon was the most frequently detected pesticide and the pesticide detected at the highest concentrations, 10 other pesticides were detected in the samples collected. These included the insecticides methidathion and chlorpyrifos, and the herbicides simazine, molinate and thiobencarb.

  15. Developmental cholinotoxicants: nicotine and chlorpyrifos.

    PubMed

    Slotkin, T A

    1999-02-01

    The stimulation of cholinergic receptors in target cells during a critical developmental period provides signals that influence cell replication and differentiation. Accordingly, environmental agents that promote cholinergic activity evoke neurodevelopmental damage because of the inappropriate timing or intensity of stimulation. Nicotine evokes mitotic arrest in brain cells possessing high concentrations of nicotinic cholinergic receptors. In addition, the cholinergic overstimulation programs the expression of genes that evoke apoptosis and delayed cell loss. Effects of cholinesterase inhibitors exhibit many similarities to those of nicotine. Chlorpyrifos administered to developing rats in doses that do not evoke signs of overt toxicity decreased DNA synthesis and caused shortfalls in cell numbers in brain regions enriched in cholinergic innervation. In embryo cultures, chlorpyrifos also evoked apoptosis during neurulation. However, chlorpyrifos also evokes noncholinergic disruption of cell development by interfering with cell signaling via adenylyl cyclase, leading to widespread disruption that is not limited to cholinergic systems. We have tested this hypothesis in vitro with PC12 cells, which lack the enzymes necessary to produce chlorpyrifos oxon, the metabolite that inhibits cholinesterase. Chlorpyrifos inhibited DNA synthesis in undifferentiated PC12 cells, which have relatively few cholinergic receptors. Furthermore, chlorpyrifos was more effective than nicotine and its effects were not blocked by cholinergic antagonists. When cells were allowed to differentiate in the presence of chlorpyrifos, cell replication was inhibited even more profoundly and cell acquisition was arrested. At higher concentrations, chlorpyrifos also inhibited neuritic outgrowth. Thus, chlorpyrifos elicits damage by both noncholinergic and cholinergic mechanisms extending from early stages of neural cell replication through late stages of axonogenesis and terminal differentiation

  16. Developmental cholinotoxicants: nicotine and chlorpyrifos.

    PubMed Central

    Slotkin, T A

    1999-01-01

    The stimulation of cholinergic receptors in target cells during a critical developmental period provides signals that influence cell replication and differentiation. Accordingly, environmental agents that promote cholinergic activity evoke neurodevelopmental damage because of the inappropriate timing or intensity of stimulation. Nicotine evokes mitotic arrest in brain cells possessing high concentrations of nicotinic cholinergic receptors. In addition, the cholinergic overstimulation programs the expression of genes that evoke apoptosis and delayed cell loss. Effects of cholinesterase inhibitors exhibit many similarities to those of nicotine. Chlorpyrifos administered to developing rats in doses that do not evoke signs of overt toxicity decreased DNA synthesis and caused shortfalls in cell numbers in brain regions enriched in cholinergic innervation. In embryo cultures, chlorpyrifos also evoked apoptosis during neurulation. However, chlorpyrifos also evokes noncholinergic disruption of cell development by interfering with cell signaling via adenylyl cyclase, leading to widespread disruption that is not limited to cholinergic systems. We have tested this hypothesis in vitro with PC12 cells, which lack the enzymes necessary to produce chlorpyrifos oxon, the metabolite that inhibits cholinesterase. Chlorpyrifos inhibited DNA synthesis in undifferentiated PC12 cells, which have relatively few cholinergic receptors. Furthermore, chlorpyrifos was more effective than nicotine and its effects were not blocked by cholinergic antagonists. When cells were allowed to differentiate in the presence of chlorpyrifos, cell replication was inhibited even more profoundly and cell acquisition was arrested. At higher concentrations, chlorpyrifos also inhibited neuritic outgrowth. Thus, chlorpyrifos elicits damage by both noncholinergic and cholinergic mechanisms extending from early stages of neural cell replication through late stages of axonogenesis and terminal differentiation

  17. Diazinon residues in insects from sprayed tobacco

    USGS Publications Warehouse

    Stromborg, K.L.; Beyer, W.N.; Kolbe, E.

    1982-01-01

    Pooled samples of tobacco hornworms collected from a field sprayed with 0.84 kg/ha of diazinon were analyzed for residues at various intervals after application. No residues of the toxic metabolite diazoxon were detected (sensitivity 0.5 ppm) in any sample. Only one sample exceeded 1.0 ppm of the parent compound and was collected 4 hours after spraying. Residues declined over time (P<0.01) and none were detected (sensitivity 0.1 ppm) 18 days after spraying. the potential hazard to birds eating these insects appeared to be minimal.

  18. Reproductive tests of diazinon on bobwhite quail

    USGS Publications Warehouse

    Stromborg, K.L.; Lamb, D.W.; Kenaga, E.E.

    1981-01-01

    Diazinon was fed at sublethal levels to reproductively active bobwhite (Colinus virginianus). Thirty pairs were given constant concentrations (0, 35. 50, 72, 104, or 150 ppm) for 3 weeks (Constant group). Another 30 pairs (Pair-fed group) were matched to these by body weights and were fed the amounts of untreated food consumed by corresponding Constant pairs to evaluate the effect of food deprivation. To mimic environmental degradation, a group of 30 pairs (Decreasing group) was initially given diazinon at the same concentrations as the Constant group; the concentration was decreased geometrically every 3 days to yield a 50 percent reduction in 15 days. Following 3 weeks of exposure to the experimental diets, pairs were maintained for an additional 3 weeks on untreated food to measure the birds' recovery. Food consumption, egg production, and hatchability were recorded for each pair. Individually hatched chicks were banded and kept for 2 weeks to monitor their survival. Food consumption was negatively dose-related above 35 ppm in the Constant and Decreasing groups. The only reproductive parameter affected was egg production. Production declined as the dose was increased above 35 ppm in the Constant and Decreasing groups. Egg laying was reduced more in the Constant than in the Decreasing pairs. The egg-laying rate of the Constant and Pair-fed groups differed; this difference was reflected by a threshold corresponding to 72 ppm in the Pair-fed group as opposed to 35 ppm in the Constant group. Residual effects of prior treatment on food consumption and egg production were observed in the Constant and Pair-fed pairs during the posttreatment period, but the Decreasing pairs were not influenced by prior treatment. The magnitude of effects related to the dose was not as great during the posttreatment period as during the treatment period and represented the recovery from diazinon effects over the span of the posttreatment period. The schedule of doses for the Decreasing

  19. IN-RESIDENCE, MULTIPLE ROUTE EXPOSURES TO CHLORPYRIFOS AND DIAZINON ESTIMATED BY INDIRECT METHOD MODELS

    EPA Science Inventory

    One of the objectives of the National Human Exposure Assessment Survey (NHEXAS) is to estimate exposures to several pollutants in multiple media and determine their distributions for the population of Arizona. This paper presents modeling methods used to estimate exposure dist...

  20. Isolation and characterization of a novel native Bacillus thuringiensis strain BRC-HZM2 capable of degrading chlorpyrifos.

    PubMed

    Wu, Songqing; Peng, Yan; Huang, Zhangmin; Huang, Zhipeng; Xu, Lei; Ivan, Gelbič; Guan, Xiong; Zhang, Lingling; Zou, Shuangquan

    2015-03-01

    Studies were carried out to isolate chlorpyrifos degrading Bacillus thuringiensis (Bt) strains from chlorpyrifos-contaminated samples. Six Bt strains (isolation rate 2.7%) were isolated by modified sodium acetate antibiotic heat treatment, and one novel strain (BRC-HZM2) was selected for further analysis. Phenotype and phylogeny analysis of this strain was conducted on the basis of biochemical reactions, antibiotic sensitivity, 16s rRNA genes, plasmid profile, insecticidal crystal protein profiles, and PCR-RFLP for cry and cyt genes. The degradation rate of chlorpyrifos in liquid culture was estimated during 48 h of incubation for the isolate BRC-HZM2. More than 50% of the initial chlorpyrifos concentration degraded within 12 h, 88.9% after 48 h. These results highlight the potential of the Bt strain for biological control and the bioremediation of environments contaminated with chlorpyrifos.

  1. Transport of diazinon in the San Joaquin River basin, California

    USGS Publications Warehouse

    Kratzer, Charles R.

    1997-01-01

    Most of the application of the organophosphate insecticide diazinon in the San Joaquin River Basin occurs in winter to control wood boring insects in dormant almond orchards. A federal-state collaborative study found that diazinon accounted for most of the observed toxicity of San Joaquin River water to water fleas in February 1993. Previous studies focussed mainly on west-side inputs to the San Joaquin River. In this 1994 study, the three major east-side tributaries to the San Joaquin River, the Merced, Tuolumne, and Stanislaus Rivers, and a downstream site on the San Joaquin River were sampled throughout the hydrographs of a late January and an early February storm. In both storms, the Tuolumne River had the highest concentrations of diazinon and transported the largest load of the three tributaries. The Stanislaus River was a small source in both storms. On the basis of previous storm sampling and estimated traveltimes, ephemeral west-side creeks were probably the main diazinon source early in the storms, while the Tuolumne and Merced Rivers and east-side drainage directly to the San Joaquin River were the main sources later. Although 74 percent of diazinon transport in the San Joaquin River during 199193 occurred in January and February, transport during each of the two 1994 storms was only 0.05 percent of the amount applied during preceeding dry periods. Nevertheless, some of the diazinon concentrations in the San Joaquin River during the January storm exceeded 0.35 micrograms per liter, a concentration shown to be acutely toxic to water fleas. Diazinon concentrations were highly variable during the storms and frequent sampling was required to adequately describe the concentration curves and to estimate loads.

  2. Transport of diazinon in the San Joaquin River Basin, California

    USGS Publications Warehouse

    Kratzer, C.R.

    1999-01-01

    Most of the application of the organophosphate insecticide diazinon in the San Joaquin River Basin occurs in winter to control wood-boring insects in dormant almond orchards. A federal-state collaborative study found that diazinon accounted for most of the observed toxicity of San Joaquin River water in February 1993. Previous studies focused mainly on west-side inputs to the San Joaquin River. In this 1994 study, the three major east-side tributaries to the San Joaquin River - the Merced, Tuolumne, and Stanislaus rivers - and a downstream site on the San Joaquin River were sampled throughout the hydrographs of a late January and an early February storm. In both storms, the Tuolumne River had the highest concentrations of diazinon and transported the largest load of the three tributaries. The Stanislaus River was a small source in both storms. On the basis of previous storm sampling and estimated travel times, ephemeral west-side creeks probably were the main diazinon source early in the storms, whereas the Tuolumne and Merced rivers and east-side drainages directly to the San Joaquin River were the main sources later. Although 74 percent of diazinon transport in the San Joaquin River during 1991-1993 occurred in January and February, transport during each of the two 1994 storms was only 0.05 percent of the amount applied during preceding dry periods. Nevertheless, some of the diazinon concentrations in the San Joaquin River during the January storm exceeded 0.35 ??g/L, a concentration shown to be acutely toxic to water fleas. On the basis of this study and previous studies, diazinon concentrations and streamflow are highly variable during January and February storms, and frequent sampling is required to evaluate transport in the San Joaquin River Basin.

  3. Diazinon degradation by a novel strain Ralstonia sp. DI-3 and X-ray crystal structure determination of the metabolite of diazinon.

    PubMed

    Wang, Guangli; Liu, Yuan

    2016-09-01

    Diazinon is a widely used organophosphorus insecticide often detected in the environment. A highly effective diazinon-degrading Ralstonia sp. strain DI-3 was isolated from agricultural soil. Strain DI-3 can utilize dimethoate as its sole carbon source for growth and degrade an initial concentration of 100 mg L-1 diazinon to non-detectable levels within 60 h in liquid culture. A small amount of second carbon source as co-substrate could slightly enhance the biodegradation of diazinon. In addition, a less toxic metabolic intermediate formed during the degradation of diazinon mediated by strain DI-3 was purified using thin-layer chromatography (TLC) and identified based on single-crystal Xray diffraction analysis, allowing a degradation pathway for diazinon by pure culture to be proposed. Finally, this is the first providing authentic evidence to describe the metabolite. PMID:27581928

  4. IMMUNOASSAY ANALYSIS FOR CHLORPYRIFOS IN FOODS

    EPA Science Inventory

    Chlorpyrifos is widely used in agriculture on fruits and vegetables. The tolerances for chlorpyrifos on produce range from 0.1-8.0 ppm. Residue detection is commonly performed by gas chromatography following various cleanup procedures. However, the required cleanup can make ...

  5. Influence of cimetidine on the toxicity and toxicokinetics of diazinon in the rat.

    PubMed

    Wu, H X; Evreux-Gros, C; Descotes, J

    1996-05-01

    1. The influence of cimetidine on diazinon toxicity and toxicokinetics was investigated in male Wistar rats. 2. The acute toxicity of diazinon, as well as brain acetylcholinesterase and carboxylesterase inhibition, were potentiated by pretreating rats with cimetidine (80 mg kg-1, i.p.) 1 and 24 h prior to diazinon application (50 mg kg-1, i.p.). 3. Comparison of toxicokinetic parameters between control and cimetidine-treated animals, showed a significant decrease in diazinon total body clearance and a marked increase in the area under the plasma concentration-time curve following cimetidine. 4. These results indicate that a major cause of the potentiation of diazinon may be related to the increase in the amount of diazinon in the systemic circulation as well as in the brain. PMID:8735462

  6. Prenatal nicotine alters the developmental neurotoxicity of postnatal chlorpyrifos directed toward cholinergic systems: better, worse, or just "different?".

    PubMed

    Slotkin, Theodore A; Seidler, Frederic J

    2015-01-01

    This study examines whether prenatal nicotine exposure sensitizes the developing brain to subsequent developmental neurotoxicity evoked by chlorpyrifos, a commonly-used insecticide. We gave nicotine to pregnant rats throughout gestation at a dose (3mg/kg/day) producing plasma levels typical of smokers; offspring were then given chlorpyrifos on postnatal days 1-4, at a dose (1mg/kg) that produces minimally-detectable inhibition of brain cholinesterase activity. We evaluated indices for acetylcholine (ACh) synaptic function throughout adolescence, young adulthood and later adulthood, in brain regions possessing the majority of ACh projections and cell bodies; we measured nicotinic ACh receptor binding, hemicholinium-3 binding to the presynaptic choline transporter and choline acetyltransferase activity, all known targets for the adverse developmental effects of nicotine and chlorpyrifos given individually. By itself nicotine elicited overall upregulation of the ACh markers, albeit with selective differences by sex, region and age. Likewise, chlorpyrifos alone had highly sex-selective effects. Importantly, all the effects showed temporal progression between adolescence and adulthood, pointing to ongoing synaptic changes rather than just persistence after an initial injury. Prenatal nicotine administration altered the responses to chlorpyrifos in a consistent pattern for all three markers, lowering values relative to those of the individual treatments or to those expected from simple additive effects of nicotine and chlorpyrifos. The combination produced global interference with emergence of the ACh phenotype, an effect not seen with nicotine or chlorpyrifos alone. Given that human exposures to nicotine and chlorpyrifos are widespread, our results point to the creation of a subpopulation with heightened vulnerability.

  7. Prenatal nicotine alters the developmental neurotoxicity of postnatal chlorpyrifos directed toward cholinergic systems: better, worse, or just "different?".

    PubMed

    Slotkin, Theodore A; Seidler, Frederic J

    2015-01-01

    This study examines whether prenatal nicotine exposure sensitizes the developing brain to subsequent developmental neurotoxicity evoked by chlorpyrifos, a commonly-used insecticide. We gave nicotine to pregnant rats throughout gestation at a dose (3mg/kg/day) producing plasma levels typical of smokers; offspring were then given chlorpyrifos on postnatal days 1-4, at a dose (1mg/kg) that produces minimally-detectable inhibition of brain cholinesterase activity. We evaluated indices for acetylcholine (ACh) synaptic function throughout adolescence, young adulthood and later adulthood, in brain regions possessing the majority of ACh projections and cell bodies; we measured nicotinic ACh receptor binding, hemicholinium-3 binding to the presynaptic choline transporter and choline acetyltransferase activity, all known targets for the adverse developmental effects of nicotine and chlorpyrifos given individually. By itself nicotine elicited overall upregulation of the ACh markers, albeit with selective differences by sex, region and age. Likewise, chlorpyrifos alone had highly sex-selective effects. Importantly, all the effects showed temporal progression between adolescence and adulthood, pointing to ongoing synaptic changes rather than just persistence after an initial injury. Prenatal nicotine administration altered the responses to chlorpyrifos in a consistent pattern for all three markers, lowering values relative to those of the individual treatments or to those expected from simple additive effects of nicotine and chlorpyrifos. The combination produced global interference with emergence of the ACh phenotype, an effect not seen with nicotine or chlorpyrifos alone. Given that human exposures to nicotine and chlorpyrifos are widespread, our results point to the creation of a subpopulation with heightened vulnerability. PMID:25510202

  8. [Photochemical degradation of chlorpyrifos in water].

    PubMed

    Wu, Xiangwei; Hua, Rimao; Tang, Feng; Li, Xuede; Cao, Haiqun; Yue, Yongde

    2006-07-01

    In this paper, the effects of different light sources, temperature, pH, and water quality on the photochemical degradation of clilorpyrifos in water were examined under natural and simulated solar irradiation. The results showed that the photochemical degradation of chlorpyrifos in water followed the first order reaction, and its half-life was 0.62, 6.92, 19.74 and 22.50 h under high pressure mercury lamp (HPML), xenon lamp (XL), ultraviolet lamp (UV), and sunlight (SL) irradiation, respectively. Temperature had a significant effect on the degradation rate of chlorpyrifos, which was increased with increasing temperature and reached the maximum at 35 degrees C. The degradation rate of chlorpyrifos was stable both in acid and in neutral buffer solution, but enhanced in alkaline buffer solution. Water quality also had a significant effect, with a decreasing degradation rate of chlorpyrifos in the sequence of distilled water > tap water > river water > lake wate > paddy water.

  9. Biodegradation of chlorpyrifos by bacterial genus Pseudomonas.

    PubMed

    Gilani, Razia Alam; Rafique, Mazhar; Rehman, Abdul; Munis, Muhammad Farooq Hussain; Rehman, Shafiq Ur; Chaudhary, Hassan Javed

    2016-02-01

    Chlorpyrifos is an organophosphorus pesticide commonly used in agriculture. It is noxious to a variety of organisms that include living soil biota along with beneficial arthropods, fish, birds, humans, animals, and plants. Exposure to chlorpyrifos may cause detrimental effects as delayed seedling emergence, fruit deformities, and abnormal cell division. Contamination of chlorpyrifos has been found about 24 km from the site of its application. There are many physico-chemical and biological approaches to remove organophosphorus pesticides from the ecosystem, among them most promising is biodegradation. The 3,5,6-trichloro-2-pyridinol (TCP) and diethylthiophosphate (DETP) as primary products are made when chlorpyrifos is degraded by soil microorganisms which further break into nontoxic metabolites as CO(2), H(2)O, and NH(3). Pseudomonas is a diversified genus possessing a series of catabolic pathways and enzymes involved in pesticide degradation. Pseudomonas putida MAS-1 is reported to be more efficient in chlorpyrifos degradation by a rate of 90% in 24 h among Pseudomonas genus. The current review analyzed the comparative potential of bacterial species in Pseudomonas genus for degradation of chlorpyrifos thus, expressing an ecofriendly approach for the treatment of environmental contaminants like pesticides.

  10. Environmental degradation of chlorpyrifos in soil

    SciTech Connect

    Cink, J.H.; Coats, J.R.

    1995-12-31

    Dursban TC has become the most widely used insecticide for the control of termites since the banning of chlordane. Several laboratory studies have been conducted to investigate the degradation kinetics of chlorpyrifos applied to soil at termiticide rates. These have included a limited number of soil types and have utilized tightly regulated environmental conditions. A field study was established to investigate the degradation of chlorpyrifos in soil treated with a 1% solution via trench application and under natural environmental conditions. Once treated, soil samples were removed from the trench at scheduled intervals and extracted to determine the concentration chlorpyrifos remaining. In three of the soils studied, the concentration of chlorpyrifos decreased dramatically within the first three months. The remaining soils showed a steady decline in concentration over 12 months. After this initial phase of degradation, the slope of the degradation curve changed sharply. This may indicate that chlorpyrifos undergoes two phases of degradation in soil. Using both phases of the degradation curves may give a better estimate of the concentration of chlorpyrifos that may be present in a soil at any time period.

  11. Biodegradation of chlorpyrifos by bacterial genus Pseudomonas.

    PubMed

    Gilani, Razia Alam; Rafique, Mazhar; Rehman, Abdul; Munis, Muhammad Farooq Hussain; Rehman, Shafiq Ur; Chaudhary, Hassan Javed

    2016-02-01

    Chlorpyrifos is an organophosphorus pesticide commonly used in agriculture. It is noxious to a variety of organisms that include living soil biota along with beneficial arthropods, fish, birds, humans, animals, and plants. Exposure to chlorpyrifos may cause detrimental effects as delayed seedling emergence, fruit deformities, and abnormal cell division. Contamination of chlorpyrifos has been found about 24 km from the site of its application. There are many physico-chemical and biological approaches to remove organophosphorus pesticides from the ecosystem, among them most promising is biodegradation. The 3,5,6-trichloro-2-pyridinol (TCP) and diethylthiophosphate (DETP) as primary products are made when chlorpyrifos is degraded by soil microorganisms which further break into nontoxic metabolites as CO(2), H(2)O, and NH(3). Pseudomonas is a diversified genus possessing a series of catabolic pathways and enzymes involved in pesticide degradation. Pseudomonas putida MAS-1 is reported to be more efficient in chlorpyrifos degradation by a rate of 90% in 24 h among Pseudomonas genus. The current review analyzed the comparative potential of bacterial species in Pseudomonas genus for degradation of chlorpyrifos thus, expressing an ecofriendly approach for the treatment of environmental contaminants like pesticides. PMID:26837064

  12. Engineering chlorpyrifos-degrading Stenotrophomonas sp. YC-1 for heavy metal accumulation and enhanced chlorpyrifos degradation.

    PubMed

    Liu, Ruihua; Jiang, Hong; Xu, Ping; Qiao, Chuanling; Zhou, Qixing; Yang, Chao

    2014-11-01

    Many ecosystems are currently co-contaminated with pesticides and heavy metals, such as chlorpyrifos and cadmium. A promising strategy to remediate mixed chlorpyrifos-cadmium-contaminated sites is the use of chlorpyrifos-degrading bacteria endowed with cadmium removal capabilities. In this work, a gene coding for synthetic phytochelatins (EC20) with high cadmium-binding capacity was introduced into a chlorpyrifos-degrading bacterium, Stenotrophomonas sp. YC-1, resulting in an engineered strain with both cadmium accumulation and chlorpyrifos degradation capabilities. To improve the cadmium-binding efficiency of whole cells, EC20 was displayed on the cell surface of Stenotrophomonas sp. YC-1 using the truncated ice nucleation protein (INPNC) anchor. The surface localization of the INPNC-EC20 fusion protein was demonstrated by cell fractionation, Western blot analysis, and immunofluorescence microscopy. Expression of EC20 on the cell surface not only improved cadmium binding, but also alleviated the cellular toxicity of cadmium. As expected, the chlorpyrifos degradation rate was reduced in the presence of cadmium for cells without EC20 expression. However, expression of EC20 (higher cadmium accumulation) completely restored the level of chlorpyrifos degradation. These results demonstrated that EC20 expression not only enhanced cadmium accumulation, but also reduced the toxic effect of cadmium on chlorpyrifos degradation. PMID:25151179

  13. Chlorpyrifos, chlorpyrifos-oxon, and diisopropylfluorophosphate inhibit kinesin-dependent microtubule motility

    SciTech Connect

    Gearhart, Debra A. . E-mail: dgearhar@mcg.edu; Sickles, Dale W.; Buccafusco, Jerry J.; Prendergast, Mark A.; Terry, Alvin V.

    2007-01-01

    Diisopropylfluorophosphate, originally developed as a chemical warfare agent, is structurally similar to nerve agents, and chlorpyrifos has extensive worldwide use as an agricultural pesticide. While inhibition of cholinesterases underlies the acute toxicity of these organophosphates, we previously reported impaired axonal transport in the sciatic nerves from rats treated chronically with subthreshold doses of chlorpyrifos. Those data indicate that chlorpyrifos (and/or its active metabolite, chlorpyrifos-oxon) might directly affect the function of kinesin and/or microtubules-the principal proteins that mediate anterograde axonal transport. The current report describes in vitro assays to assess the concentration-dependent effects of chlorpyrifos (0-10 {mu}M), chlorpyrifos-oxon (0-10 {mu}M), and diisopropylfluorophosphate (0-0.59 nM) on kinesin-dependent microtubule motility. Preincubating bovine brain microtubules with the organophosphates did not alter kinesin-mediated microtubule motility. In contrast, preincubation of bovine brain kinesin with diisopropylfluorophosphate, chlorpyrifos, or chlorpyrifos-oxon produced a concentration-dependent increase in the number of locomoting microtubules that detached from the kinesin-coated glass cover slip. Our data suggest that the organophosphates-chlorpyrifos-oxon, chlorpyrifos, and diisopropylfluorophosphate-directly affect kinesin, thereby disrupting kinesin-dependent transport on microtubules. Kinesin-dependent movement of vesicles, organelles, and other cellular components along microtubules is fundamental to the organization of all eukaryotic cells, especially in neurons where organelles and proteins synthesized in the cell body must move down long axons to pre-synaptic sites in nerve terminals. We postulate that disruption of kinesin-dependent intracellular transport could account for some of the long-term effects of organophosphates on the peripheral and central nervous system.

  14. Movement of Diazinon Residues into Homes Following Applications of a Granular Formulation to Residential Lawns

    EPA Science Inventory

    A pilot study was conducted to examine the movement of diazinon following applications of a granular formulation to residential lawns. The objectives included examining the transport and fate of diazinon from an outdoor source to the indoor living areas of six homes, and estimati...

  15. Degradation of chlorpyrifos in tropical rice soils.

    PubMed

    Das, Subhasis; Adhya, Tapan K

    2015-04-01

    Chlorpyrifos [O,O-diethyl O-(3,5,6-trichloro-2-pyridinol) phosphorothioate] is used worldwide as an agricultural insecticide against a broad spectrum of insect pests of economically important crops including rice, and soil application to control termites. The insecticide mostly undergoes hydrolysis to diethyl thiophosphoric acid (DETP) and 3,5,6-trichloro-2-pyridinol (TCP), and negligible amounts of other intermediate products. In a laboratory-cum-greenhouse study, chlorpyrifos, applied at a rate of 10 mg kg(-1) soil to five tropical rice soils of wide physico-chemical variability, degraded with a half-life ranging from 27.07 to 3.82 days. TCP was the major metabolite under both non-flooded and flooded conditions. Chlorpyrifos degradation had significant negative relationship with electrical conductivity (EC), cation exchange capacity (CEC), clay and sand contents of the soils under non-flooded conditions. Results indicate that degradation of chlorpyrifos was accelerated with increase in its application frequency, across the representative rice soils. Management regimes including moisture content and presence or absence of rice plants also influenced the process. Biotic factors also play an important role in the degradation of chlorpyrifos as demonstrated by its convincing degradation in mineral salts medium inoculated with non-sterile soil suspension. PMID:25617866

  16. An invertebrate model of the developmental neurotoxicity of insecticides: effects of chlorpyrifos and dieldrin in sea urchin embryos and larvae.

    PubMed Central

    Buznikov, G A; Nikitina, L A; Bezuglov, V V; Lauder, J M; Padilla, S; Slotkin, T A

    2001-01-01

    Chlorpyrifos targets mammalian brain development through a combination of effects directed at cholinergic receptors and intracellular signaling cascades that are involved in cell differentiation. We used sea urchin embryos as an invertebrate model system to explore the cellular mechanisms underlying the actions of chlorpyrifos and to delineate the critical period of developmental vulnerability. Sea urchin embryos and larvae were exposed to chlorpyrifos at different stages of development ranging from early cell cleavages through the prism stage. Although early cleavages were unaffected even at high chlorpyrifos concentrations, micromolar concentrations added at the mid-blastula stage evoked a prominent change in cell phenotype and overall larval structure, with appearance of pigmented cells followed by their accumulation in an extralarval cap that was extruded from the animal pole. At higher concentrations (20-40 microM), these abnormal cells constituted over 90% of the total cell number. Studies with cholinergic receptor blocking agents and protein kinase C inhibitors indicated two distinct types of effects, one mediated through stimulation of nicotinic cholinergic receptors and the other targeting intracellular signaling. The effects of chlorpyrifos were not mimicked by chlorpyrifos oxon, the active metabolite that inhibits cholinesterase, nor by nonorganophosphate cholinesterase inhibitors. Dieldrin, an organochlorine that targets GABA(A )receptors, was similarly ineffective. The effects of chlorpyrifos and its underlying cholinergic and signaling-related mechanisms parallel prior findings in mammalian embryonic central nervous system. Invertebrate test systems may thus provide both a screening procedure for potential neuroteratogenesis by organophosphate-related compounds, as well as a system with which to uncover novel mechanisms underlying developmental vulnerability. PMID:11485862

  17. Physiologically Based Pharmacokinetic/Pharmacodynamic Model for the Organophosphorus Pesticide Diazinon

    SciTech Connect

    Poet, Torka S.; Kousba, Ahmed A.; Dennison, Stephanie L.; Timchalk, Chuck

    2004-12-01

    Organophosphate (OP) insecticides like diazinon (DZN) constitute a large class of chemical insecticides that are widely utilized. The potential exists for significant exposures to a combination of OP pesticides from multiple routes. The objective of this research was to develop a physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) model capable of predicting the relationships between exposure route, bioactivation, detoxification, and acetylcholinesterase (AChE) inhibition. CYP450-mediated metabolism of DZN to the active oxon leads to inhibition of AChE at nerve endings. CYP450s also mediate detoxification of DZN to its pyrimidinol and A-esterase detoxifies the oxon to the pyrimidinol. The ultimate goal is to use this model to quantify systemic dosimetry and biological response from available environmental and personal exposure data. The model structure integrates CYP450 and esterase metabolism, route-dependent absorption, target tissue dosimetry, and dynamic response, to predict circulating blood levels of DZN and esterase inhibition in target organs. Metabolic rate constants for the CYP450-mediated conversion to the active oxon and the inactive pyrimidinol and the esterase-mediated deactivation of the oxon have been measured in vitro. The inhibition of AChE activity is a sensitive and relatively easy measure of exposure and is therefore the preferred descriptive endpoint. Esterase inhibition and regeneration rates have been described using in vitro calculations and parameter optimization to fit the model to AChE inhibition data. This descriptive model for DZN has been developed and has been shown to predict blood levels of the parent chemical and AChE inhibition in animal models. This PBPK/PD model will be linked to a existing PBPK model for chlorpyrifos to estimate the effects of exposures to a mixture of OPs and to describe target tissue dosimetry and effects in humans. These biologically relevant PBPK models will be integral to risk assessments for

  18. Variation characteristics of chlorpyrifos in nonsterile wetland plant hydroponic system.

    PubMed

    Wang, Chuan; Zhou, Qiaohong; Zhang, Liping; Zhang, Yan; Xiao, Enrong; Wu, Zhenbin

    2013-01-01

    Six wetland plants were investigated for their effect on the degradation characteristics of chlorpyrifos in nonsterile hydroponic system at constant temperature of 28 degrees C. The results showed that the removal rates of chlorpyrifos in the water of plant systems were 1.26-5.56% higher than that in the control without plants. Scirpus validus and Typha angustifolia were better than other hygrophytes in elimination of chlorpyrifos. The removal rates of the two systems were up to 88%. Plants of acaulescent group had an advantage over caulescent group in removing chlorpyrifos. Phytoaccumulation of chlorpyrifos was observed, and the order of chlorpyrifos concentration in different plant tissues was root > stem > leaf. It was also found that chlorpyrifos and its metabolite TCP decreased rapidly at the initial step of the experiment.

  19. Diazinon transport through inter-row vegetative filter strips: micro-ecosystem modeling

    NASA Astrophysics Data System (ADS)

    Watanabe, H.; Grismer, M. E.

    2001-07-01

    The efficacy of inter-row vegetative filter strips (VFS) for controlling runoff of the commonly used organo-phosphate insecticide (diazinon) from dormant-sprayed orchards was investigated through development of physical (micro-ecosystem) models. The micro-ecosystem consisted of a pesticide sprayer, rainfall simulator and orchard floor model with and without VFS. Diazinon was sprayed at a rate of 2.8 kg/ha, 24 h prior to rainfall simulation. Rainfall, at an intensity of 50 mm/h and 44% of the natural rainfall energy, was simulated for 60 min. Experiments were conducted for 0, 50 and 100% VFS soil coverage. Diazinon concentrations in runoff, interflow and baseflow, and also in soil and vegetative samples were measured in order to quantify transport/adsorption processes. Total diazinon losses as a fraction of applied pesticide mass from the orchard floor following rainfall-runoff simulation were 8.6, 5.8 and 2.3%, respectively, for the 0, 50 and 100% VFS cover treatments. Diazinon runoff concentrations decreased with time during the rainfall simulation, but at a slower rate in the VFS treatments as compared to the bare soil treatment apparently due to washoff from the sod leaves. The principle mechanism of diazinon runoff control in VFS was diversion of runoff, the primary pesticide carrier, into interflow through the rootzone and mainly vertical infiltration (baseflow) such that the diazinon was trapped on the VFS surface and in its rootzone. In fact, 37 and 88% of the applied diazinon remained as residue in the VFS vegetative matter and rootzone for the 50 and 100% VFS treatments, respectively, following rainfall simulation. Results from the micro-ecosystem suggest that inter-row VFS should be effective in reducing diazinon runoff from dormant-sprayed orchards. These results are used to calibrate a field-applicable numerical model for development of pesticide runoff control strategies, or best management practices (BMP's).

  20. Performance assessment and validation of a paramagnetic particle-based enzyme-linked immunosorbent assay for chlorpyrifos in agricultural runoff waters.

    PubMed

    Sullivan, Jonathan J; Chen, Ye Grace; Goh, Kean S

    2007-08-01

    A commercial magnetic particle-based enzyme-linked immunosorbent assay (ELISA) kit for the insecticide chlorpyrifos [O,O-diethyl-O-(3,5,6-trichloro-2-pyridyl) phosphorothioate] was evaluated for its specificity, precision, and accuracy, its susceptibility to matrix interferences in agricultural and environmental surface waters, and its comparability to a gas chromatographic/flame photometric (GC/FPD) method for the determination of organophosphorus pesticides in natural waters. Repeatability, reproducibility, and accuracy studies show that the kit satisfies current U.S. Environmental Protection Agency criteria for the assessment of analytical methods. Observable matrix effects were found to be present in all of the environmental test waters, with the slopes of calibration curves generated in each of the test matrices deviating from that of the control matrix by as much as 16%. Specificity studies indicate that the chlorpyrifos polyclonal antibody adequately differentiates the target compound from other structurally similar organophosphorus pesticides, with the exception of its methyl analogue. Cross-reactivity with chlorpyrifos-methyl was approximately 37%, while reactivity with diazinon, pyridaphenthion, diclofenthion, bromiphos-ethyl, bromiphos-methyl, pirimiphos-ethyl, and chlorpyrifos oxon ranged from 1.6 to 10.7%. Cross-reactivity with pirimiphos-methyl, 3,5,6-trichloro-2-pyridinol, diethyl phosphate, and diethyl thiophosphate was negligible (<1%). Validation of the paramagnetic particle ELISA format was accomplished using water samples from two monitoring studies that were collected, split, and analyzed directly by ELISA and by GC/FPD. Results of the two analytical methods were then compared using standard t tests, regression analysis, and differences against mean measurement (bias) plots. While the agreement between the two methods was determined to be satisfactory, ELISA exhibits consistent positive bias in environmental matrices. Several preanalysis

  1. Biodegradation and bioremediation potential of diazinon-degrading Serratia marcescens to remove other organophosphorus pesticides from soils.

    PubMed

    Cycoń, Mariusz; Żmijowska, Agnieszka; Wójcik, Marcin; Piotrowska-Seget, Zofia

    2013-03-15

    The ability of diazinon-degrading Serratia marcescens to remove organophosphorus pesticides (OPPs), i.e. chlorpyrifos (CP), fenitrothion (FT), and parathion (PT) was studied in a mineral salt medium (MSM) and in three soils of different characteristics. This strain was capable of using all insecticides at concentration of 50 mg/l as the only carbon source when grown in MSM, and 58.9%, 70.5%, and 82.5% of the initial dosage of CP, FT, and PT, respectively was degraded within 14 days. The biodegradation experiment showed that autochthonous microflora in all soils was characterized by a degradation potential of all tested OPPs; however, the initial lag phases for degradation of CP and FT, especially in sandy soil, were observed. During the 42-day experiment, 45.3%, 61.4% and 72.5% of the initial dose of CP, FT, and PT, respectively, was removed in sandy soil whereas the degradation of CP, FT, and PT in the same period, in sandy loam and silty soils reached 61.4%, 79.7% and 64.2%, and 68.9%, 81.0% and 63.6%, respectively. S. marcescens introduced into sterile soils showed a higher degradation potential (5-13%) for OPPs removal than those observed in non-sterile soil with naturally occurring attenuation. Inoculation of non-sterile soils with S. marcescens enhanced the disappearance rates of all insecticides, and DT50 for CP, FT, and PT was reduced by 20.7, 11.3 and 13.0 days, and 11.9, 7.0 and 8.1 days, and 9.7, 14.5 and 12.6 days in sandy, sandy loam, and silty soils, respectively, in comparison with non-sterile soils with only indigenous microflora. This ability of S. marcescens makes it a suitable strain for bioremediation of soils contaminated with OPPs.

  2. Persistent Cognitive Alterations in Rats after Early Postnatal Exposure to Low Doses of the Organophosphate Pesticide, Diazinon

    PubMed Central

    Timofeeva, Olga A.; Roegge, Cindy S.; Seidler, Frederic J.; Slotkin, Theodore A.; Levin, Edward D.

    2008-01-01

    Background Developmental neurotoxicity of organophosphorous insecticides (OPs) involves multiple mechanisms in addition to cholinesterase inhibition. We have found persisting effects of developmental chlorpyrifos (CPF) and diazinon (DZN) on cholinergic and serotonergic neurotransmitter systems and gene expression as well as behavioral function. Both molecular/neurochemical and behavioral effects of developmental OP exposure have been seen at doses below those which cause appreciable cholinesterase inhibition. Objectives We sought to determine if developmental DZN exposure at doses which do not produce significant acetylcholinesterase inhibition cause cognitive deficits. Methods Rats were exposed to DZN on postnatal days 1-4 at doses (0.5 and 2 mg/kg/d) that span the threshold for cholinesterase inhibition. They were later examined with a cognitive battery tests similar to that used with CPF. Results In the T-maze DZN caused significant hyperactivity in the initial trials of the session, but not later. In a longer assessment of locomotor activity no DZN-induced changes were seen over a 1-hour session. Prepulse inhibition was reduced by DZN exposure selectively in males vs. females; DZN eliminated the sex difference present in controls. In the radial maze, the lower but not higher DZN dose significantly impaired spatial learning. This has previously been seen with CPF as well. The lower dose DZN group also showed significantly greater sensitivity to the memory-impairing effects of the anticholinergic drug scopolamine. Conclusions Neonatal DZN exposure below the threshold for appreciable cholinesterase inhibition caused neurocognitive deficits in adulthood. The addition of some inhibition of AChE with a higher dose reversed the cognitive impairment. This non-monotonic dose-effect function has also been seen with neurochemical effects. Some of the DZN effects on cognition resemble those seen earlier for CPF, some differ. Our data suggest that DZN and CPF affect

  3. Brain cholinesterase response in the snakehead fish (Channa striata) after field exposure to diazinon.

    PubMed

    Nguyen, Van Cong; Nguyen, Thanh Phuong; Bayley, Mark

    2008-10-01

    The snakehead Channa striata is an economically important air-breathing fish species in the Mekong delta of Vietnam. Rice paddies, which are disturbed by the frequent application of agro-chemicals, are among the preferred habitats for this species during the rainy season. Diazinon is one of most commonly used chemicals in rice paddies. In the present study, exposure of adult snakehead fish to a single diazinon application in cages within a rice field resulted in long-term brain cholinesterase inhibition, while the water concentration of this insecticide fell below the detection limit within 3 days. In addition, incubation of brain homogenates with 2-PAM caused reactivation of the cholinesterase diazinon complex to within 80% of the control level. These experiments also showed that chemical ageing of the diazinon cholinesterase binding occurred, which may explain the long-term effects of this pesticide.

  4. Lactobacillus Casei Decreases Organophosphorus Pesticide Diazinon Cytotoxicity in Human HUVEC Cell Line

    PubMed Central

    Bagherpour Shamloo, Hasan; Golkari, Saber; Faghfoori, Zeinab; Movassaghpour, AliAkbar; Lotfi, Hajie; Barzegari, Abolfazl; Yari Khosroushahi, Ahmad

    2016-01-01

    Purpose: Exposure to diazinon can trigger acute and chronic toxicity and significantly induces DNA damage and proapoptotic effects in different human cells. Due to the significance of probiotic bacteria antitoxin effect, this study aimed to investigate the effect of Lactobacillus casei on diazinon (DZN) cytotoxicity in human umbilical vein endothelial cells (HUVEC) in vitro. Methods: The cytotoxicity assessments were performed by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) test, DAPI (4',6-diamidino-2-phenylindole) staining and flow cytometric methodologies. Results: Cytotoxic assessments through flow cytometry/ DAPI staining demonstrated that apoptosis is the main cytotoxic mechanism of diazinon in HUVEC cells and L. casei could decrease the diazinon cytotoxic effects on toxicants. Conclusion: the screen of total bacterial secreted metabolites can be considered as a wealthy source to find the new active compounds to introduce as reducing agricultural remained pesticide cytotoxicity effects on the human food chain. PMID:27478782

  5. Brain cholinesterase response in the snakehead fish (Channa striata) after field exposure to diazinon.

    PubMed

    Nguyen, Van Cong; Nguyen, Thanh Phuong; Bayley, Mark

    2008-10-01

    The snakehead Channa striata is an economically important air-breathing fish species in the Mekong delta of Vietnam. Rice paddies, which are disturbed by the frequent application of agro-chemicals, are among the preferred habitats for this species during the rainy season. Diazinon is one of most commonly used chemicals in rice paddies. In the present study, exposure of adult snakehead fish to a single diazinon application in cages within a rice field resulted in long-term brain cholinesterase inhibition, while the water concentration of this insecticide fell below the detection limit within 3 days. In addition, incubation of brain homogenates with 2-PAM caused reactivation of the cholinesterase diazinon complex to within 80% of the control level. These experiments also showed that chemical ageing of the diazinon cholinesterase binding occurred, which may explain the long-term effects of this pesticide. PMID:18514898

  6. The gas-phase degradation of chlorpyrifos and chlorpyrifos-oxon towards OH radical under atmospheric conditions.

    PubMed

    Muñoz, Amalia; Ródenas, Milagros; Borrás, Esther; Vázquez, Mónica; Vera, Teresa

    2014-09-01

    The OH initiated oxidation of chlorpyrifos (a widely used insecticide) and its photooxidation product chlorpyrifos-oxon were investigated at the large outdoor European Photoreactor (EUPHORE). The rate constants for reaction of chlorpyrifos and chlorpyrifos oxon with OH radicals were measured using a conventional relative rate method. The value of the OH reaction rate constants with chlorpyrifos and chlorpyrifos-oxon were determined to be k=(9.1±2.1)×10(-11)cm(3)molecule(-1)s(-1) and (1.7±0.9)×10(-11)cm(3)molecule(-1)s(-1) at 303±5K and atmospheric pressure. They gave an atmospheric lifetime in relation to the reaction with OH of approximately 2h and 11h for chlorpyrifos and chlorpyrifos-oxon, respectively. Photolysis was found to be unimportant relative to reaction with OH. The main products detected in the gas phase from the reaction of OH with chlorpyrifos were SO2, chlorpyrifos-oxon, 3,5,6-trichloro-2-pyridinol and diethylphosphate with molar yields of 17±5%, ∼10%, 8±4% and 30±9%, respectively.

  7. Application of Acoustical Processor Reactors for Degradation of Diazinon from Surface Water

    PubMed Central

    Shayeghi, M; Dehghani, MH; Mahvi, AH; Azam, K

    2010-01-01

    Background: Since organophosphorus pesticides are widely used for industry and insect control in agricultural crops, their fate in the environment is very important. Pesticide contamination of surface water has been recognized as a major contaminant in world because of their potential toxicity towards human and animals. The objective of this research was to investigate the influence of various parameters including the influence of time, power, and initial concentration on degradation of diazinon pesticide. Methods: The sonochemical degradation of diazinon was investigated using acoustical processor reactor. Acoustical processor reactor with 130 kHz was used to study the degradation of pesticide solution. Samples were analyzed using HPLC at different time intervals. Effectiveness of APR at different times (20, 40, 60, 80, 100, and 120 min), concentrations (2, 4 and 8 mg/L) and powers (300W, 400W, 500W) were compared. Results: The degradation of the diazinon at lower concentrations was greater in comparison to higher concentrations. There was also direct correlation between power and diazinon degradation. In addition, when the power increased, the ability to degraded diazinon increased. Conclusion: The sonodegradation of diazinon pesticide at different concentrations and powers was successfully provided. It has been shown that APR can be used to reduce the concentration of dissolved pesticide using high frequency. PMID:22808395

  8. Determination of water sources contamination to diazinon and malathion and spatial pollution patterns in Qazvin, Iran.

    PubMed

    Karyab, Hamid; Mahvi, Amir Hossein; Nazmara, Shahrokh; Bahojb, Akram

    2013-01-01

    A questionnaire study and field visit showed that diazinon and malathion were the most commonly used pesticides in Qazvin province, Iran. Concentrations of these pesticides were determined in water sources; include springs, wells and Shahrood River. Springs water samples had the best water quality; but deep wells were the most polluted water samples. Diazinon was detected in 46.6 % of the samples, while malathion occurrences frequency was in 13.3 % of the samples. Diazinon and malathion were detected in maximum concentration of 19.44 and 18.12 μg L(-1), respectively. The obtained results showed that diazinon was detected in higher than life-time health advisories in wells and in Shahrood River samples; so, it can bring up threats to human health. Interpolation of diazinon and malathion in water sources showed that diazinon had the most widely scattering condition in deep wells. Also, cross validation with the root mean square error (RMSE) indicated that the natural neighbor interpolation of malathion has the minimum RMSE.

  9. Alteration of protein profile in rat liver of animals exposed to subacute diazinon: a proteomic approach.

    PubMed

    Lari, Parisa; Rashedinia, Marzieh; Abnous, Khalil; Hosseinzadeh, Hossein

    2014-05-01

    Diazinon, an organophosphorus insecticide, is employed to control pests in agriculture. Diazinon may contaminate the environment during the manufacturing process or agricultural application. Previous studies have revealed that diazinon may induce alteration in the protein profile of the liver. Here, a proteomics approach was used to investigate the effects on the protein profile in the liver of rats of subacute oral exposures at 15 mg/kg of diazinon. Liver proteins were separated using 2D-PAGE, and stained by MS-compatible silver staining and/or the fluorescent SYPRO® Ruby protein gel stain. Gels were scanned and analyzed using the Image Master software. Differentially displayed protein species were identified using MALDI-TOF/TOF and MASCOT software. Significantly altered protein species were identified to be involved in apoptosis, cell metabolism, transport, and antioxidant systems. Exposure to diazinon decreased levels of some species of catalase, peroxiredoxin-6, 3-ketoacyl-CoA thiolase, and glucose regulated protein78, whereas the level of protein disulfide-isomerase A3 increased. Our results suggested that diazinon may induce hepatotoxicity through oxidative stress, apoptosis, and metabolic disorders in rat liver.

  10. Gamma-ray induced degradation of diazinon and atrazine in natural groundwaters.

    PubMed

    Mohamed, K A; Basfar, A A; Al-Shahrani, A A

    2009-07-30

    Degradation of diazinon and atrazine pesticides present in natural groundwaters was investigated on a laboratory scale upon gamma-irradiation from a (60)Co source. The effects of pesticide type, initial concentration, characteristics of natural groundwater, potential radical scavengers and absorbed dose on efficiency of pesticide degradation were investigated using GC-MS. gamma-Irradiation experiments were carried out for three concentrations (i.e. 0.329, 1.643 and 3.286 microM/diazinon and 0.464, 2.318 and 4.636 microM/atrazine) with irradiation doses over the range 0.5-5.6 kGy for diazinon and 0.2-21 kGy for atrazine. gamma-Radiolysis showed that diazinon was much easier to degrade by ionizing radiation compared to atrazine in all natural groundwater samples. This was observed at the three initial concentrations over the range irradiation doses. The irradiation doses required for degradation of 50 and 90% diazinon (distilled water) and atrazine (humic aqueous solution) at the three concentrations were not sufficient to degrade the same concentrations in different natural groundwater samples. Moreover, the presence of naturally occurring inorganic scavengers in solutions of diazinon and atrazine decreased significantly the efficiency of radiolytic degradation of pesticides, especially at higher concentrations.

  11. Diazinon concentrations in the Sacramento and San Joaquin Rivers and San Francisco Bay, California, February 1993

    USGS Publications Warehouse

    Kuivila, Kathryn M.

    1993-01-01

    The distribution and possible biological effects of a dormant spray pesticide, diazinon, were examined by measuring pesticide concentrations and estimating toxicity using bioassays at a series of sites in the Sacramento-San Joaquin Delta and San Francisco Bay. Pulses of diazinon were observed in early February 1993 in the Sacramento and San Joaquin Rivers after heavy rains, with elevated concentrations measured for a few days to weeks at a time. The pulse of diazinon in the Sacramento River was followed from Sacramento through Suisun Bay, the eastward embayment of San Francisco Bay. In the central delta, well-defined pulses of diazinon were not observed at the Old and Middle River sites; instead, the concentrations steadily increased throughout February. Ceriodaphnia dubia mortality was 100% in water samples collected for 12 consecutive days (February 8-19) from the San Joaquin River at Vernalis. The bioassay mortality corresponded with the peak diazinon concentrations. Conversely, no toxicity was observed in water collected before or after peaks of diazinon concentration. Other pesticides present also could contribute to the toxicity.

  12. Impact of atrazine on chlorpyrifos toxicity in four aquatic vertebrates.

    PubMed

    Wacksman, M N; Maul, J D; Lydy, M J

    2006-11-01

    Atrazine has been shown previously to potentiate chlorpyrifos toxicity in selected invertebrates. This study examined interactions of atrazine and chlorpyrifos in four aquatic vertebrates. Organisms were exposed to binary mixtures of atrazine and chlorpyrifos during toxicity bioassays. Inhibition of cholinesterase (ChE) enzyme activity and chlorpyrifos uptake kinetics were also examined with and without atrazine exposure. Atrazine alone did not affect organisms at concentrations up to 5000 microg/L; however, the presence of atrazine at 1000 microg/L did result in a significant increase in the acute toxicity of chlorpyrifos in Xenopus laevis. Mixed results were encountered with Pimephales promelas; some bioassays showed greater than additive toxicity, while others showed an additive response. No effect of atrazine on chlorpyrifos toxicity was observed for Lepomis macrochirus and Rana clamitans. Atrazine did not affect ChE activity or chlorpyrifos uptake rates, indicating that these toxicodynamic and toxicokinetic parameters may not be related to the mechanism of atrazine potentiation of chlorpyrifos toxicity. Based on the results of this study, it does not appear that a mixture toxicity of atrazine and chlorpyrifos at environmentally relevant concentrations presents a risk to the vertebrate organisms examined in this study.

  13. Diazinon in surface waters before and after a federally-mandated ban.

    PubMed

    Banks, Kenneth E; Hunter, David H; Wachal, David J

    2005-11-01

    Samples collected from rural and urban streams in the City of Denton, Texas, USA were analyzed for the organophosphorus pesticide diazinon during the years preceding and following a United States Environmental Protection Agency ban on many diazinon uses. A network of 70 monitoring stations, based mainly on topography and hydrological considerations, were established within the three main watersheds of Denton. Monitoring stations were sampled monthly from March through August during periods of normal flow (baseflow), resulting in a total of 1243 samples collected during the years of 2001-2004. Pesticide concentrations were determined using commercially available enzyme-linked immunosorbent assays (ELISAs) specific for diazinon. Results from this temporally and spatially dense monitoring effort illustrated the impacts of a decrease in diazinon production during 2002, followed by a ban on most outdoor, non-agricultural diazinon retail sales imposed during 2003. The total number of samples exhibiting diazinon concentrations above the lower limits of detection (LLD) significantly decreased between 2001 through 2004 (Mantel-Haenszel Chi-Square test, p<0.0001, n=1243) and decreased significantly during the four monitoring years (Cochran-Armitage Trend test, z=-17.94, p<0.0001, n=1243). The total number of stations exhibiting at least one sample above the LLD during the four monitoring years showed similar patterns (Mantel-Haenszel Chi-Square test, p<0.0001; Cochran-Armitage Trend test, z=-3.21, p=0.0007; n=276). Results indicate that the phased reduction of outdoor, non-agricultural diazinon uses led to a highly significant decrease in surface water occurrences of this pesticide.

  14. The effects of diazinon and cypermethrin on the differentiation of neuronal and glial cell lines

    SciTech Connect

    Flaskos, J.; Harris, W.; Sachana, M.; Munoz, D.; Tack, J.; Hargreaves, A.J. . E-mail: alan.hargreaves@ntu.ac.uk

    2007-03-15

    Diazinon and cypermethrin are pesticides extensively used in sheep dipping. Diazinon is a known anti-cholinesterase, but there is limited information regarding its molecular mechanism of action. This paper describes the effects of diazinon and cypermethrin at a morphological and molecular level on differentiating mouse N2a neuroblastoma and rat C6 glioma cell lines. Concentrations up to 10 {mu}M of both compounds and their mixture had no effect on the viability of either cell line, as determined by methyl blue tetrazolium reduction and total protein assays. Microscopic analysis revealed that 1 {mu}M and 10 {mu}M diazinon but not cypermethrin inhibited the outgrowth of axon-like processes in N2a cells after a 24-h exposure but neither compound affected process outgrowth by differentiating C6 cells at these concentrations. Under these conditions, 10 {mu}M diazinon inhibited AChE slightly compared to the control after a 4-h exposure but not after 24 h. Western blotting analysis showed that morphological changes were associated with reduced cross-reactivity with antibodies that recognize the neurofilament heavy chain (NFH), microtubule associated protein MAP 1B and HSP-70 compared to control cell extracts, whereas reactivity with anti-{alpha}-tubulin antibodies was unchanged. Aggregation of NFH was observed in cell bodies of diazinon-treated N2a cells, as determined by indirect immunofluorescence staining. These data demonstrate that diazinon specifically targets neurite outgrowth in neuronal cells and that this effect is associated with disruption of axonal cytoskeleton proteins, whereas cypermethrin has no effect on the same parameters.

  15. Increased diazinon hydrolysis to 2-isopropyl-6-methyl-4-pyrimidinol in liquid medium by a specific Streptomyces mixed culture.

    PubMed

    Briceño, G; Schalchli, H; Rubilar, O; Tortella, G R; Mutis, A; Benimeli, C S; Palma, G; Diez, M C

    2016-08-01

    Actinobacteria identified as Streptomyces spp. were evaluated for their ability to remove diazinon as the only carbon source from a liquid medium. Single cultures of Streptomyces strains were exposed to diazinon at a concentration of 50 mg L(-1). After 96 h incubation, six of the eight cultures grew and five strains showed an increase in their total protein concentrations and changes in their protein profile. Up to 32% of the diazinon was removed by the single Streptomyces cultures. A compatibility assay showed that the different Streptomyces species were not antagonistic. Twenty-six mixed cultures were then prepared. Diazinon removal was increased when mixed cultures were used, and maximum diazinon removal of 62% was observed when the Streptomyces spp. strains AC5, AC9, GA11 and ISP13 were mixed; this was defined as the selected mixed culture (SMC). Diazinon removal was positively influenced by the addition of glucose into the liquid medium. Our study showed a diazinon degradation rate of 0.025 h(-1), half-life of 28 h(-1) and 2-isopropyl-6-methyl-4-pyrimidinol (IMHP) production of 0.143 mg L h(-1). Rapid diazinon hydrolysis to IMHP was associated with a decrease in the pH of the medium as a consequence of microbial glucose metabolism and organic acid exudation. Moreover, the SMC of Streptomyces was able to remove IMHP. This work constitutes a new, if not the only, report on diazinon degradation by mixed cultures of Streptomyces spp. Given the high levels of diazinon removal, the SMC formed by four Streptomyces strains has the potential to be used to treat the diazinon present in environmental matrices. PMID:27176942

  16. Increased diazinon hydrolysis to 2-isopropyl-6-methyl-4-pyrimidinol in liquid medium by a specific Streptomyces mixed culture.

    PubMed

    Briceño, G; Schalchli, H; Rubilar, O; Tortella, G R; Mutis, A; Benimeli, C S; Palma, G; Diez, M C

    2016-08-01

    Actinobacteria identified as Streptomyces spp. were evaluated for their ability to remove diazinon as the only carbon source from a liquid medium. Single cultures of Streptomyces strains were exposed to diazinon at a concentration of 50 mg L(-1). After 96 h incubation, six of the eight cultures grew and five strains showed an increase in their total protein concentrations and changes in their protein profile. Up to 32% of the diazinon was removed by the single Streptomyces cultures. A compatibility assay showed that the different Streptomyces species were not antagonistic. Twenty-six mixed cultures were then prepared. Diazinon removal was increased when mixed cultures were used, and maximum diazinon removal of 62% was observed when the Streptomyces spp. strains AC5, AC9, GA11 and ISP13 were mixed; this was defined as the selected mixed culture (SMC). Diazinon removal was positively influenced by the addition of glucose into the liquid medium. Our study showed a diazinon degradation rate of 0.025 h(-1), half-life of 28 h(-1) and 2-isopropyl-6-methyl-4-pyrimidinol (IMHP) production of 0.143 mg L h(-1). Rapid diazinon hydrolysis to IMHP was associated with a decrease in the pH of the medium as a consequence of microbial glucose metabolism and organic acid exudation. Moreover, the SMC of Streptomyces was able to remove IMHP. This work constitutes a new, if not the only, report on diazinon degradation by mixed cultures of Streptomyces spp. Given the high levels of diazinon removal, the SMC formed by four Streptomyces strains has the potential to be used to treat the diazinon present in environmental matrices.

  17. Effect of exposure to diazinon on adult rat's brain.

    PubMed

    Rashedinia, Marzieh; Hosseinzadeh, Hossein; Imenshahidi, Mohsen; Lari, Parisa; Razavi, Bibi Marjan; Abnous, Khalil

    2016-04-01

    Diazinon (DZN), a commonly used agricultural organophosphate insecticide, is one of the major concerns for human health. This study was planned to investigate neurotoxic effects of subacute exposure to DZN in adult male Wistar rats. Animals received corn oil as control and 15 and 30 mg/kg DZN orally by gastric gavage for 4 weeks. The cerebrum malondialdehyde and glutathione (GSH) contents were assessed as biomarkers of lipid peroxidation and nonenzyme antioxidants, respectively. Moreover, activated forms of caspase 3, -9, and Bax/Bcl-2 ratios were evaluated as key apoptotic proteins. Results of this study suggested that chronic administration of DZN did not change lipid peroxidation and GSH levels significantly in comparison with control. Also, the active forms of caspase 3 and caspase 9 were not significantly altered in DZN-treated rat groups. Moreover, no significant changes were observed in Bax and Bcl-2 ratios. This study indicated that generation of reactive oxygen species was probably modulated by intracellular antioxidant system. In conclusion, subacute oral administration of DZN did not alter lipid peroxidation. Moreover, apoptosis induction was not observed in rat brain.

  18. Particulate and gas-phase products from the atmospheric degradation of chlorpyrifos and chlorpyrifos-oxon

    NASA Astrophysics Data System (ADS)

    Borrás, Esther; Ródenas, Milagros; Vázquez, Mónica; Vera, Teresa; Muñoz, Amalia

    2015-12-01

    The phosphorothioate structure is highly present in several pesticides. However, there is a lack of information about its degradation process in air and the secondary pollutants formed. Herein, the atmospheric reactions of chlorpyrifos, one of the most world-used insecticide, and its main degradation product - chlorpyrifos-oxon - are described. The photo-oxidation under the presence of NOx was studied in a large outdoor simulation chamber for both chlorpyrifos and chlorpyrifos-oxon, observing a rapid degradation (Half lifetime < 3.5 h for both compounds). Also, the photolysis reactions of both were studied. The formation of particulate matter (aerosol mass yield ranged 6-59%) and gaseous products were monitored. The chemical composition of minor products was studied, identifying 15 multi-oxygenated derivatives. The most abundant products were ring-retaining molecules such as 3,5,6-trichloropyridin-2-ol and ethyl 3,5,6-trichloropyridin-2-yl hydrogen phosphate. An atmospheric degradation mechanism has been amplified based on an oxidation started with OH-nucleophilic attack to Pdbnd S bond.

  19. Effects of a diazinon formulation on unialgal growth rates and phytoplankton diversity

    SciTech Connect

    Doggett, S.M.; Rhodes, R.G. )

    1991-07-01

    Diazinon and other organophosphorus insecticides are used primarily for their broad effectiveness, short persistence, and relatively low mammalian toxicity. Although these insecticides are less toxic to algae than most organochlorines, the extensive use of Diazinon and the subsequent exposure to aquatic communities may pose a serious threat to algal growth and population diversity. The significance of phytoplankton as primary producers as well as their ability to intrinsically alter the balance of aquatic ecosystems has warranted greater concern for the toxic effects of this widely accepted insecticide. Few reports are available on the effects of Diazinon on nontarget aquatic organisms and even less is known about its effects on algal growth and phytoplankton diversity. In light of the sparse information available on the effects of Diazinon on phytoplankton population dynamics, the objectives of this study were: (1) to determine the effects of a Diazinon formulation on the growth rates of three widely distributed species of freshwater algae, (2) to ascertain the effects of this formulation on the diversity of a natural phytoplankton assemblage.

  20. Linkage of biomarkers along levels of biological complexity in juvenile and adult diazinon fed terrestrial isopod (Porcellio scaber, Isopoda, Crustacea).

    PubMed

    Stanek, Katja; Drobne, Damjana; Trebse, Polonca

    2006-09-01

    In parallel laboratory experiments, we determined the effect of a typical representative of organophosphorous pesticides, diazinon, on AChE activity, lipid, protein and glycogen content, weight change, feeding activity and mortality of juvenile and adult terrestrial isopods Porcellio scaber (Isopoda, Crustacea). Organophosphorous pesticides (OP) are among the most extensively used pesticides, which have replaced organochlorine pesticides. OPs inhibit the enzyme acetylcholinesterase (AChE), resulting in neurotoxicity. They have more widespread effects on non-target organisms than do organochlorine pesticides. The aim of this study was to link effect of diazinon on target enzyme to energy reserves and to integrated biomarker responses in juvenile and adult P. scaber. The non-observed effect concentration (NOEC) for AChE activity after diazinon exposure in two weeks toxicity study with isopods was below 5 microg/g diazinon. There was a good agreement between concentrations at which AChE and survival were affected (10 microg/g diazinon in juveniles, 100 microg/g diazinon in adults). We revealed a link among AChE activity, protein content and mortality. Glycogen and lipid content, feeding activity and weight change were not affected in two weeks diazinon exposure up to 100 microg/g diazinon. Juveniles were affected at concentrations that were an order of magnitude lower than those provoking similar effects on adults. Recommendations are made for future toxicity studies with terrestrial isopods.

  1. Lipid peroxidation and decline in antioxidant status as one of the toxicity measures of diazinon in the testis.

    PubMed

    Leong, Chong Thau; D'Souza, Urban J A; Iqbal, Mohammad; Mustapha, Zainal Arifin

    2013-01-01

    The rapid emergence of various pesticides in the market is inevitable due to the demands from agriculture industries and domestic needs to control nuisance pests and to sustain green resources worldwide. However, long-term exposure to pesticide has led to adverse effects on male fertility. Organophosphate diazinon (O,O-diethyl-O-[2-isopropyl-6-methyl-4-pyrimidinyl] phosphorothiote) is an often abusively used pesticide, as it is effective and economical. This study is to determine the adverse effects of low-dose diazinon exposure on the male reproductive system. In this study, 72 Sprague-Dawley rats were segregated into 1, 2, and 8 weeks of exposure groups and further sub-grouped (n = 6) to receive 0, 10, 15, and 30 mg/kg body weight diazinon treatment. Rats were gavaged orally with diazinon and sacrificed under anaesthesia the day after the last exposure. Our results showed that consistent diazinon exposure decreased glutathione and catalase, and increased lipid peroxidation which together lead to diazinon-mediated oxidative stress. Additionally, diazinon increased serum lactate dehydrogenase and decreased serum testosterone, which may have caused sperm and histopathological anomalies. In conclusion, exposure to diazinon caused changes in lipid peroxidation and sperm, and these two effects might be causally linked.

  2. Effects of sub-lethal neurite outgrowth inhibitory concentrations of chlorpyrifos oxon on cytoskeletal proteins and acetylcholinesterase in differentiating N2a cells

    SciTech Connect

    Flaskos, J.; Nikolaidis, E.; Harris, W.; Sachana, M.; Hargreaves, A.J.

    2011-11-15

    Previous work in our laboratory has shown that sub-lethal concentrations (1-10 {mu}M) of chlorpyrifos (CPF), diazinon (DZ) and diazinon oxon (DZO) inhibit the outgrowth of axon-like neurites in differentiating mouse N2a neuroblastoma cells concomitant with altered levels and/or phosphorylation state of axonal cytoskeleton and growth-associated proteins. The aim of the present work was to determine whether chlorpyrifos oxon (CPO) was capable of inhibiting N2a cell differentiation in a similar manner. Using experimental conditions similar to our previous work, sub-lethal concentrations (1-10 {mu}M) of CPO were found to inhibit N2a cell differentiation. However, unlike previous studies with DZ and DZO, there was a high level of sustained inhibition of acetylcholinesterase (AChE) in CPO treated cells. Impairment of neurite outgrowth was also associated with reduced levels of growth associated protein-43 and neurofilament heavy chain (NFH), and the distribution of NFH in cells stained by indirect immunofluorescence was disrupted. However, in contrast to previous findings for DZO, the absolute level of phosphorylated NFH was unaffected by CPO exposure. Taken together, the findings suggest that sub-lethal concentrations of CPO inhibit axon outgrowth in differentiating N2a cells and that this effect involves reduced levels of two proteins that play key roles in axon outgrowth and maintenance. Although the inhibition of neurite outgrowth is unlikely to involve AChE inhibition directly, further work will help to determine whether the persistent inhibition of AChE by CPO can account for the different effects induced by CPO and DZO on the levels of total and phosphorylated NFH. -- Highlights: Black-Right-Pointing-Pointer Sub-lethal levels of chlorpyrifos oxon inhibit neurite outgrowth in N2a cells Black-Right-Pointing-Pointer Acetylcholinesterase exhibits sustained inhibition throughout exposure Black-Right-Pointing-Pointer The levels of neurofilament heavy chain and GAP-43

  3. Organophosphate pesticide method development and presence of chlorpyrifos in the feet of nearctic-neotropical migratory songbirds from Canada that over-winter in Central America agricultural areas.

    PubMed

    Alharbi, Hattan A; Letcher, Robert J; Mineau, Pierre; Chen, Da; Chu, Shaogang

    2016-02-01

    Recent modeling analysis suggests that numerous birds may be at risk of acute poisoning in insecticide-treated fields. Although the majority of avian field studies on pesticides have focused on treated seed, granule, insect or vegetation (oral exposure) ingestion, dermal exposure is an important exposure route when birds come into contact with deposited pesticides on foliage and other surfaces. Some nearctic-neotropical migratory songbirds are likely exposed to pesticides on their non-breeding habitats and include treated crops, plantations or farmlands. In the present study, we developed a method for four environmentally-relevant organophosphate (OP) pesticides (fenthion, fenamiphos, chlorpyrifos and diazinon) in the feet of migratory songbirds (i.e. Common yellowthroat, Gray catbird, Indigo bunting, America redstart, Northern waterthrush, Northern parula, and an additional 12 species of warblers). A total of 190 specimens of the 18 species of songbirds were sampled from available window-killed birds (spring of 2007 and 2011) in downtown Toronto, Canada. The species that were available most likely over-wintered in Mexican/Central American crops such as citrus, coffee and cacao. The feet of the dead birds were sampled and where OP foot exposure likely occurred during over-wintering foraging on pesticide-treated crops. Chlorpyrifos was the only measurable OP (pg mg feet weight(-1)) and in the 2011-collected feet of Black throated blue warbler (0.5), Tennessee warbler (1.0), Northern parula (1.2), Northern waterthrush (0.6), Common yellowthroat (1.0) and the Blue winged warbler (0.9). Dermal contact with OP pesticides during over-wintering in agricultural areas resulted in low levels of chlorpyrifos and long time retention on the feet of a subset of songbirds. PMID:26421621

  4. Organophosphate pesticide method development and presence of chlorpyrifos in the feet of nearctic-neotropical migratory songbirds from Canada that over-winter in Central America agricultural areas.

    PubMed

    Alharbi, Hattan A; Letcher, Robert J; Mineau, Pierre; Chen, Da; Chu, Shaogang

    2016-02-01

    Recent modeling analysis suggests that numerous birds may be at risk of acute poisoning in insecticide-treated fields. Although the majority of avian field studies on pesticides have focused on treated seed, granule, insect or vegetation (oral exposure) ingestion, dermal exposure is an important exposure route when birds come into contact with deposited pesticides on foliage and other surfaces. Some nearctic-neotropical migratory songbirds are likely exposed to pesticides on their non-breeding habitats and include treated crops, plantations or farmlands. In the present study, we developed a method for four environmentally-relevant organophosphate (OP) pesticides (fenthion, fenamiphos, chlorpyrifos and diazinon) in the feet of migratory songbirds (i.e. Common yellowthroat, Gray catbird, Indigo bunting, America redstart, Northern waterthrush, Northern parula, and an additional 12 species of warblers). A total of 190 specimens of the 18 species of songbirds were sampled from available window-killed birds (spring of 2007 and 2011) in downtown Toronto, Canada. The species that were available most likely over-wintered in Mexican/Central American crops such as citrus, coffee and cacao. The feet of the dead birds were sampled and where OP foot exposure likely occurred during over-wintering foraging on pesticide-treated crops. Chlorpyrifos was the only measurable OP (pg mg feet weight(-1)) and in the 2011-collected feet of Black throated blue warbler (0.5), Tennessee warbler (1.0), Northern parula (1.2), Northern waterthrush (0.6), Common yellowthroat (1.0) and the Blue winged warbler (0.9). Dermal contact with OP pesticides during over-wintering in agricultural areas resulted in low levels of chlorpyrifos and long time retention on the feet of a subset of songbirds.

  5. Effects of repeated exposure of diazinon on cholinesterase activity and growth in snakehead fish (Channa striata).

    PubMed

    Cong, Nguyen Van; Phuong, Nguyen Thanh; Bayley, Mark

    2009-03-01

    The organophosphate insecticide diazinon is widely used in the Mekong river delta and often applied several times per rice crop. In the present study, juvenile snakehead fish Channa striata, which is a commercially important inhabitant of rice fields, were exposed twice to 4-day pulses of 0.016, 0.079 or 0.35mg/L of diazinon, separated by a 2 week interval to imitate the exposure conditions in the field. After the 4-day exposures to these environmentally realistic concentrations, the fish were moved to clean water for recovery. During this experiment, which lasted a total of 2 months, the individual growth rates and brain cholinesterase levels were measured. We show not only that diazinon caused long term inhibition of brain ChE activity, which was still significantly depressed at the termination of the experiment, but also that the highest of these realistic concentrations caused a significant 30% growth inhibition.

  6. Effects of repeated exposure of diazinon on cholinesterase activity and growth in snakehead fish (Channa striata).

    PubMed

    Cong, Nguyen Van; Phuong, Nguyen Thanh; Bayley, Mark

    2009-03-01

    The organophosphate insecticide diazinon is widely used in the Mekong river delta and often applied several times per rice crop. In the present study, juvenile snakehead fish Channa striata, which is a commercially important inhabitant of rice fields, were exposed twice to 4-day pulses of 0.016, 0.079 or 0.35mg/L of diazinon, separated by a 2 week interval to imitate the exposure conditions in the field. After the 4-day exposures to these environmentally realistic concentrations, the fish were moved to clean water for recovery. During this experiment, which lasted a total of 2 months, the individual growth rates and brain cholinesterase levels were measured. We show not only that diazinon caused long term inhibition of brain ChE activity, which was still significantly depressed at the termination of the experiment, but also that the highest of these realistic concentrations caused a significant 30% growth inhibition. PMID:19054558

  7. The influence of alachlor, trifluralin, and diazinon on the development of endogenous mycorrhizae in soybeans.

    PubMed

    Burpee, L L; Cole, H

    1978-02-01

    Preplant incorporated treatments of 2 and 4 kg/ha of trifluralin and diazinon had no significant effect on growth, P accumulation or root colonization by mycorrhizal fungi in soybeans planted in an Andover clay loam. At 4 kg/ha, alachlor and trifluralin inhibited root development of 25 day-old plants. The 4 kg/ha alachlor treatment reduced shoot weight of 25 day old plants significantly and suppressed mycorrhizal development of 25 to 60 day old plants. At currently used commercial rates neither alachlor, trifluralin, nor diazinon affected mycorrhizal development under the conditions of the experiment.

  8. Protein tyrosine adduct in humans self-poisoned by chlorpyrifos

    SciTech Connect

    Li, Bin; Eyer, Peter; Eddleston, Michael; Jiang, Wei; Schopfer, Lawrence M.; Lockridge, Oksana

    2013-06-15

    Studies of human cases of self-inflicted poisoning suggest that chlorpyrifos oxon reacts not only with acetylcholinesterase and butyrylcholinesterase but also with other blood proteins. A favored candidate is albumin because in vitro and animal studies have identified tyrosine 411 of albumin as a site covalently modified by organophosphorus poisons. Our goal was to test this proposal in humans by determining whether plasma from humans poisoned by chlorpyrifos has adducts on tyrosine. Plasma samples from 5 self-poisoned humans were drawn at various time intervals after ingestion of chlorpyrifos for a total of 34 samples. All 34 samples were analyzed for plasma levels of chlorpyrifos and chlorpyrifos oxon (CPO) as a function of time post-ingestion. Eleven samples were analyzed for the presence of diethoxyphosphorylated tyrosine by mass spectrometry. Six samples yielded diethoxyphosphorylated tyrosine in pronase digests. Blood collected as late as 5 days after chlorpyrifos ingestion was positive for CPO-tyrosine, consistent with the 20-day half-life of albumin. High plasma CPO levels did not predict detectable levels of CPO-tyrosine. CPO-tyrosine was identified in pralidoxime treated patients as well as in patients not treated with pralidoxime, indicating that pralidoxime does not reverse CPO binding to tyrosine in humans. Plasma butyrylcholinesterase was a more sensitive biomarker of exposure than adducts on tyrosine. In conclusion, chlorpyrifos oxon makes a stable covalent adduct on the tyrosine residue of blood proteins in humans who ingested chlorpyrifos. - Highlights: • Chlorpyrifos-poisoned patients have adducts on protein tyrosine. • Diethoxyphosphate-tyrosine does not lose an alkyl group. • Proteins in addition to AChE and BChE are modified by organophosphates.

  9. Effects of diazinon on adaptation to sea-water by the endangered Persian sturgeon, Acipenser persicus, fingerlings.

    PubMed

    Hajirezaee, Saeed; Mirvaghefi, Ali Reza; Farahmand, Hamid; Agh, Naser

    2016-11-01

    To replenish the depleting populations of sturgeon fishes especially Persian sturgeon, Acipenser persicus in the Caspian Sea, millions of Persian sturgeon fingerlings are farmed through artificial propagation and released into the Iranian river estuaries annually. Fish osmoregulation is a vital physiological process that can be affected during the release. Many Iranian river estuaries are under the influence of pesticides originating from farming activities that may affect osmoregulation. In this study, Persian sturgeon fingerlings were exposed to sublethal concentrations (0, 0.18, 0.54, 0.9mgL(-)(1)) of diazinon for 96h (short-term trial) and 12 days (long-term trial) in fresh water (FW) and then fish were exposed in brackish water (BW) for 24h. After 96h and 12 days of exposure in FW, the lower levels of plasma triidothyronine (T3), thyroxine (T4), Na(+), Cl(-), K(+), gill Na(+)/K(+)- ATPase activity and number of chloride cells were observed in exposed fish (0.54 and 0.9mgL(-)(1) diazinon) compared to control group and 0.18mgL(-)(1) diazinon treatment. Also, higher levels of plasma cortisol (except 0.18mgL(-)(1) diazinon treatment in long-term trial) were observed in diazinon exposed fish compared to control group. However, gill Na(+)/K(+)-ATPase activity and the number of chloride cells were higher in fingerlings exposed to diazinon compared than control. When fish were exposed in BW for 24h, the following changes occurred: (a) in short-term trial: increases in cortisol and Cl(-) levels (0.54mgL(-)(1) diazinon ), Na(+) (0.9mgL(-)(1) diazinon ) and gill Na(+)/K(+)-ATPase activity (0.18mgL(-)(1) diazinon ). In control group, cortisol, T4, Na(+), gill Na(+)/K(+)-ATPase activity and the number of chloride cells increased significantly. (b) In long-term trial: increases in K(+) levels in fish exposed to 0.9mgL(-)(1) diazinon, Na+ in all diazinon concentrations and decreases in chloride cells number in fish exposed to 0.18mgL(-)(1) diazinon. In control group

  10. Effects of diazinon on adaptation to sea-water by the endangered Persian sturgeon, Acipenser persicus, fingerlings.

    PubMed

    Hajirezaee, Saeed; Mirvaghefi, Ali Reza; Farahmand, Hamid; Agh, Naser

    2016-11-01

    To replenish the depleting populations of sturgeon fishes especially Persian sturgeon, Acipenser persicus in the Caspian Sea, millions of Persian sturgeon fingerlings are farmed through artificial propagation and released into the Iranian river estuaries annually. Fish osmoregulation is a vital physiological process that can be affected during the release. Many Iranian river estuaries are under the influence of pesticides originating from farming activities that may affect osmoregulation. In this study, Persian sturgeon fingerlings were exposed to sublethal concentrations (0, 0.18, 0.54, 0.9mgL(-)(1)) of diazinon for 96h (short-term trial) and 12 days (long-term trial) in fresh water (FW) and then fish were exposed in brackish water (BW) for 24h. After 96h and 12 days of exposure in FW, the lower levels of plasma triidothyronine (T3), thyroxine (T4), Na(+), Cl(-), K(+), gill Na(+)/K(+)- ATPase activity and number of chloride cells were observed in exposed fish (0.54 and 0.9mgL(-)(1) diazinon) compared to control group and 0.18mgL(-)(1) diazinon treatment. Also, higher levels of plasma cortisol (except 0.18mgL(-)(1) diazinon treatment in long-term trial) were observed in diazinon exposed fish compared to control group. However, gill Na(+)/K(+)-ATPase activity and the number of chloride cells were higher in fingerlings exposed to diazinon compared than control. When fish were exposed in BW for 24h, the following changes occurred: (a) in short-term trial: increases in cortisol and Cl(-) levels (0.54mgL(-)(1) diazinon ), Na(+) (0.9mgL(-)(1) diazinon ) and gill Na(+)/K(+)-ATPase activity (0.18mgL(-)(1) diazinon ). In control group, cortisol, T4, Na(+), gill Na(+)/K(+)-ATPase activity and the number of chloride cells increased significantly. (b) In long-term trial: increases in K(+) levels in fish exposed to 0.9mgL(-)(1) diazinon, Na+ in all diazinon concentrations and decreases in chloride cells number in fish exposed to 0.18mgL(-)(1) diazinon. In control group

  11. Endocrine-disrupting and cytotoxic potential of anticholinesterase insecticide, diazinon in reproductive toxicity of male mice.

    PubMed

    ElMazoudy, Reda H; Attia, Azza A

    2012-03-30

    We evaluated the effects of diazinon (2, 4.1 and 8.2mg/kg bw/day for 4 weeks) in gonadotropins, testosterone and estrogen levels, whether the regulatory interactions in the hypothalamic-pituitary-testicular axis are modified by acetylcholinesterase inhibition and histopathological changes in adult mice testes. Diazinon at doses higher than 2mg/kg bw/day resulted in decreased testis weight, inhibition in acetylcholinesterase activities, decrease in levels of luteinizing hormone and follicle stimulating hormone, following reduction in mating and fertility indices. Diazinon increased testosterone content in 4.1mg/kg group, but decreased testosterone concentration in 8.2mg/kg group. Diazinon increased estrogen, prolactine and decreased levels of acetylcholinesterase activities in 4.1mg/kg group but levels of luteinizing hormone and follicle stimulating hormone remained unmodified. It may be simply postulated a scenario that acetylcholine in the cholinergic neurons has a potential threshold to perform a crucial part in the complex circuitry of neuroendocrine regulatory mechanisms. On overaccumulation, other neurotransmitters can be appropriately recruited to modulate the mechanisms of circuitry.

  12. THE INTERACTION OF AN ANTICHOLINESTERASE INSECTICIDE, DIAZINON, WITH A PYRETHROID INSECTICIDE, DELTAMETHRIN.

    EPA Science Inventory

    This present study explores the interaction of the toxicity induced by an organophosphorus insecticide, diazinon (diethyl 2-isopropyl-6methyl-4-pyrimidal phosphorothionate), with a pyrethroid insecticide, deltamethrin ((S)-a-cyano-3-phenoxybenzyl (1R,3R)-3-(2,2-dibromovinyl)-2,...

  13. Effects of Subchronic Exposure to Cadmium and Diazinon on Testis and Epididymis in Rats

    PubMed Central

    Cabaj, Michal; Massanyi, Peter; Martiniakova, Monika; Omelka, Radoslav; Krajcovicova, Vladimira; Duranova, Hana

    2014-01-01

    The present study aimed to elucidate the structural changes in testis and epididymis of adult rats following subchronic peroral administration of cadmium at 30 mg/L, diazinon at 40 mg/L, cadmium at 30 mg/L, and diazinon at 40 mg/L, respectively. At the end of 90-day experiment, the samples of the testes and epididymis were assayed by qualitative and quantitative histological methods. The testis and epididymis weights increased following exposure to cadmium and simultaneous exposure to cadmium and diazinon. Testicular damage following cadmium and diazinon coexposure was significantly less expressive than in groups with individual administration of these compounds. Cadmium caused a significant thickening of seminiferous epithelium, cellular degeneration, and necrosis. Desquamation of immature germ cells resulted in a significant increase of intraepithelial spaces and reduced tubule volume in all experimental groups. Vascular dilation and congestion were detected in the interstitial tissue. The changes in epididymal histology in the group exposed to cadmium and group exposed simultaneously included a reduction of epithelium, necrotic epithelial cells, vasoconstriction, and interstitial edema together with mononuclear cell infiltration. Results did not indicate a synergistic or any additional effect from the simultaneous administration of both toxicants. Further research is needed to determine the significance and the mechanism of the adverse effects. PMID:25548789

  14. Mechanism and kinetic properties for OH-initiated atmospheric degradation of the organophosphorus pesticide diazinon

    NASA Astrophysics Data System (ADS)

    Zhou, Qin; Sun, Xiaoyan; Gao, Rui; Hu, Jingtian

    2011-06-01

    Diazinon is a member of the organophosphorus class of insecticides. It has been regarded as an important atmospheric pollutant because of its high detection-frequency in the air and potential adverse effects on humans and wildlife. In this paper, the reaction mechanism and possible degradation products for the OH-initiated atmospheric degradation of diazinon were investigated and the rate constants of crucial elementary steps over the temperature range of 180-370 K were predicted. Present results show that OH addition to C4 atom in the pyrimidyl ring, H abstraction from the -CH- moiety as well as OH addition to P atom are the dominant pathways for the reaction of diazinon with OH radicals. The dominant degradation products are diazoxon, SO 2, P3, CH 3CHO, P4, CH 3CO, P14 as well as CH 3CHCH 3. This work provides a comprehensive investigation of the OH-initiated atmospheric degradation of diazinon and should help to clarify its potential risk to non-targets.

  15. THE POTENTIAL FOR HUMAN EXPOSURES TO PET-BORNE DIAZINON RESIDUES FOLLOWING RESIDENTIAL LAWN APPLICATIONS

    EPA Science Inventory

    This observational study examined the potential for indoor/outdoor pet dogs to be an important pathway for transporting diazinon residues into homes and onto occupants following residential lawn applications. The primary objective was to investigate the potential exposures of chi...

  16. Studies on atmospheric degradation of diazinon in the EUPHORE simulation chamber.

    PubMed

    Muñoz, Amalia; Person, Annaïg Le; Calvé, Stéphane Le; Mellouki, Abdelwahid; Borrás, Esther; Daële, Véronique; Vera, Teresa

    2011-10-01

    The gas phase atmospheric degradation of diazinon has been investigated at the large outdoor European Photoreactor (EUPHORE) in Valencia, Spain. The rate constant for reaction of diazinon with OH radicals was measured using a conventional relative rate method with di-n-buthylether as reference compound being k = (3.5 ± 1.2) × 10⁻¹¹ cm³ molecule⁻¹ s⁻¹ at 302 ± 10 K and atmospheric pressure. The available evidence indicates that tropospheric degradation of diazinon is mainly controlled by reaction with OH radicals, and that the tropospheric lifetime with respect to the OH reaction is estimated to be around 4h whereas its lifetime with respect to the photolysis is higher than 1d under our conditions. Significant aerosol formation was observed following the reaction of diazinon with OH radicals, and the main carbon-containing products detected in the particle phase were hydroxydiazinon, hydroxydiazoxon and 2-isopropyl-6-methyl-pyrimidinyl-4-ol.

  17. Does diazinon pose a threat to a neighborhood stream in Tallahassee, Florida?

    USGS Publications Warehouse

    Berndt, Marian P.; Hatzell, Hilda H.

    2001-01-01

    The water quality of Lafayette Creek was studied from March 1993 to December 1995 as part of the National Water-Quality Assessment Program of the U.S.Geological Survey. Diazinon was specifically studied in the Lafayette Creek watershed, a residential area in northeastern Tallahassee, Fla. Diazinon and other pesticides applied directly to the soil or grass can be washed off into nearby storm drains, ditches, streams, and lakes. Heavy rainstorms can wash substantial amounts of chemicals into streams and lakes, including diazinon that was applied several weeks earlier. Sampling streams during rainstorms for water quality can sometimes provide clues about how pesticides and other contaminants are transported to surface water. Diazinon was detected in 92% of all samples collected from Lafayette Creek and it was detected throughout the year during the sampling period. However, concentrations were low (0.002 to 0.28 micrograms per liter) and do not pose a risk to human health. About 20% of the samples exceeded the aquatic-life criterion--a guideline that establishes the maximum acceptable level of concentrations of pesticides for protecting aquatic life.

  18. Rhizosphere remediation of chlorpyrifos in mycorrhizospheric soil using ryegrass.

    PubMed

    Korade, Deepali L; Fulekar, M H

    2009-12-30

    The potential of ryegrass for rhizosphere bioremediation of chlorpyrifos in mycorrhizal soil was investigated by the green house pot culture experiments. The pot cultured soil amended at initial chlorpyrifos concentration of 10mg/kg was observed to be degraded completely within 7 days where the rest amended concentrations (25-100mg/kg) decreased rapidly under the influence of ryegrass mycorrhizosphere as the incubation progressed till 28 days. This bioremediation of chlorpyrifos in soil is attributed to the microorganisms associated with the roots in the ryegrass rhizosphere, therefore the microorganisms surviving in the rhizospheric soil spiked at highest concentration (100mg/kg) was assessed and used for isolation of chlorpyrifos degrading microorganisms. The potential degrader identified by 16s rDNA analysis using BLAST technique was Pseudomonas nitroreducens PS-2. Further, bioaugmentation for the enhanced chlorpyrifos biodegradation was performed using PS-2 as an inoculum in the experimental set up similar to the earlier. The heterotrophic bacteria and fungi were also enumerated from the inoculated and non-inoculated rhizospheric soils. In bioaugmentation experiments, the percentage dissipation of chlorpyrifos was 100% in the inoculated rhizospheric soil as compared to 76.24, 90.36 and 90.80% in the non-inoculated soil for initial concentrations of 25, 50 and 100mg/kg at the 14th, 21st and 28th day intervals respectively.

  19. Retention and Migration of Chlorpyrifos in Aquatic Sediments and Soils

    NASA Astrophysics Data System (ADS)

    Gebremariam, S. Y.; Beutel, M.; Yonge, D.; Flury, M.; Harsh, J. B.

    2010-12-01

    The accurate description of the fate and transport of potentially toxic agricultural pesticides in sediments and soils is of great interest to environmental scientists and regulators. Of particular concern is the widely documented detection of agricultural pesticides and their byproducts in drinking water wells. This presentation discusses results of a study of the fate and transport of chlorpyrifos, a strongly hydrophobic organophosphate-pesticide, in sediments and soils collected from a range of aquatic environments. Using radio-labeled chlorpyrifos, this study is unique in its comprehensive nature and focus on aquatic sediments, for which studies involving pesticide fate and transport are limited. Study components include: (1) batch equilibrium experiments to evaluate sorption/desorption parameters; (2) kinetic and non-equilibrium sorption experiments using miniaturized flow-cells; (3) column experiments to understand patterns of pesticide break through; and (4) numerical modeling of chlorpyrifos transport through aquatic sediments and soils. Initial results show that chlorpyrifos sorption, when corrected for reversible sorption to container walls, exhibited two component sorption, a large irreversible fraction and a smaller reversible fraction that can act as a secondary source. In addition, of a wide range of soil parameters measured, organic carbon content exhibited the highest correlation with chlorpyrifos retention in cranberry field soils. Simulation models developed in this study, which account for hysteretic and nonlinear sorption, will help to better predict the fate of chlorpyrifos and other hydrophobic chemicals in sediments and soils.

  20. Human exposure and risk from indoor use of chlorpyrifos.

    PubMed Central

    Gibson, J E; Peterson, R K; Shurdut, B A

    1998-01-01

    The toxicity, exposure, and risk from chlorpyrifos are briefly discussed in juxtaposition with two recent articles in Environmental Health Perspectives concerning potential exposures to children. In studies conducted according to EPA guidelines, chlorpyrifos has been shown not to be mutagenic, carcinogenic, or teratogenic, nor does it adversely affect reproduction. Chlorpyrifos toxicity does not occur in the absence of significant cholinesterase inhibition. If exposures are less than those that cause significant cholinesterase depression, then no signs or symptoms related to chlorpyrifos exposure occur. The weight of empirical evidence indicates that the risk of adults or children experiencing an adverse health effect from exposure to chlorpyrifos through both nondietary and dietary sources is negligible. Both the research supporting the registration of these products and their long history of widespread use suggest that unless these products are seriously misused, their margins of safety are wide enough to protect everyone with the potential to be exposed. A weight-of-evidence review of the entire scientific knowledge base relating to chlorpyrifos products supports these conclusions. PMID:9618344

  1. Impact of a short-term diazinon exposure on the osmoregulation potentiality of Caspian roach (Rutilus rutilus) fingerlings.

    PubMed

    Katuli, Kheyrollah Khosravi; Amiri, Bagher Mojazi; Massarsky, Andrey; Yelghi, Saeed; Ghasemzadeh, Javad

    2014-08-01

    The stocks of Caspian roach (Rutilus rutilus), an economically important species in the Caspian Sea, are depleting. Each year millions of artificially produced fingerlings of this species are restocked in the mouth of rivers of the Southern Caspian Sea (e.g. Qare Soo River), where they are exposed to pesticides originating from regional rice and orchard fields. This early exposure to pesticides could affect the hypo-osmoregulatory ability of juvenile fish. Thus, in this study, Caspian roach fingerlings were exposed to environmentally-relevant concentrations of the organophosphate insecticide diazinon for 96 h in fresh water and then transferred to diazinon-free brackish water (BW) for another 96 h. We report that cortisol and glucose levels were significantly increased in all diazinon treatments at all sampling time points in comparison to the control group. Moreover, the thyroid hormone levels of TSH, T4, and T3 significantly decreased in diazinon-exposed fish even after the transfer to BW. The electrolytes were differentially affected during the exposure to diazinon and after the transfer to BW. The number of chloride cells in the gill tissue was significantly increased during diazinon exposure at the higher concentrations and decreased to control levels after transfer to BW. Finally, gill and kidney tissues showed many histopathological changes in diazinon-exposed fish even after 240 h in BW. These results suggest that the release of Caspian roach fingerlings into the diazinon-contaminated Caspian Sea regions may alter their physiology and jeopardize their survival, which could lead to a failure in rebuilding the Caspian roach stocks in the Caspian Sea.

  2. Mobility Studies of (14)C-Chlorpyrifos in Malaysian Oil Palm Soils.

    PubMed

    Halimah, Muhamad; Ismail, B Sahid; Nashriyah, Mat; Maznah, Zainol

    2016-01-01

    The mobility of (14)C-chlorpyrifos using soil TLC was investigated in this study. It was found that chlorpyrifos was not mobile in clay, clay loam and peat soil. The mobility of (14)C-chlorpyrifos and non-labelled chlorpyrifos was also tested with silica gel TLC using three types of developing solvent hexane (100%), hexane:ethyl acetate (95:5, v/v); and hexane:ethyl acetate (98:2, v/v). The study showed that both the (14)C-labelled and non-labelled chlorpyrifos have the same Retardation Factor (Rf) for different developing solvent systems. From the soil column study on mobility of chlorpyrifos, it was observed that no chlorpyrifos residue was found below 5 cm depth in three types of soil at simulation rainfall of 20, 50 and 100 mm. Therefore, the soil column and TLC studies have shown similar findings in the mobility of chlorpyrifos.

  3. Mobility Studies of (14)C-Chlorpyrifos in Malaysian Oil Palm Soils.

    PubMed

    Halimah, Muhamad; Ismail, B Sahid; Nashriyah, Mat; Maznah, Zainol

    2016-01-01

    The mobility of (14)C-chlorpyrifos using soil TLC was investigated in this study. It was found that chlorpyrifos was not mobile in clay, clay loam and peat soil. The mobility of (14)C-chlorpyrifos and non-labelled chlorpyrifos was also tested with silica gel TLC using three types of developing solvent hexane (100%), hexane:ethyl acetate (95:5, v/v); and hexane:ethyl acetate (98:2, v/v). The study showed that both the (14)C-labelled and non-labelled chlorpyrifos have the same Retardation Factor (Rf) for different developing solvent systems. From the soil column study on mobility of chlorpyrifos, it was observed that no chlorpyrifos residue was found below 5 cm depth in three types of soil at simulation rainfall of 20, 50 and 100 mm. Therefore, the soil column and TLC studies have shown similar findings in the mobility of chlorpyrifos. PMID:26546229

  4. CHLORPYRIFOS TRANSFORMATION BY AQUEOUS CHLORINE IN THE PRESENCE OF BROMIDE AND NATURAL ORGANIC MATTER

    EPA Science Inventory

    The aqueous chlorination of chlorpyrifos (CP) was investigated in the presence of bromide and natural organic matter (NOM), which were identified as naturally occurring aqueous constituents that could impact CP transformation rates to the toxic product chlorpyrifos oxon (CPO). Br...

  5. Transformation of Chlorpyrifos and Chlorpyrifos-Methyl in Prairie Pothole Porewaters

    NASA Astrophysics Data System (ADS)

    Anderson, R. M.; Chin, Y. P.

    2014-12-01

    The prairie pothole region (PPR) extends over approximately 700,000 km2 in the Great Plains region in United States and Canada and is a critical breeding ground for migratory waterfowl, as well as an important ecosystem for diverse invertebrates and aquatic plants (van der Valk, 2003). Consisting of up to 12 million permanent and temporary depressional wetlands, the PPR is negatively impacted by non-point source pesticide pollution due to extensive agricultural development in the region. Recent studies have shown that high (mM) levels of sulfate in the pothole lakes are capable of abiotically reducing dinitroaniline and chloroacetanilide pesticides (Zeng, 2011; Zeng, 2012). In this study the transformation of the organophosphorus pesticide chlorpyrifos (CP) and its analog chlorpyrifos-methyl (CPM) was studied using pore waters sampled from two pothole lakes. CP and CPM have been found to react in the laboratory with sulfur species via a SN2 mechanism, with degradation by sulfur compounds occurring faster than hydrolysis at high pH (Wu, 2006). To date the reaction of CP and CPM in natural environments with sulfur species has not been studied. Chlorpyrifos-methyl underwent rapid degradation in the presence of reduced sulfur species in pore water, while chlorpyrifos degradation occurred at significantly slower rates. Both CP and CPM degradation occurred at comparable rates to what has been previously observed in the laboratory (Wu, 2006). References van der Valk, Arnold G., and Roger L. Pederson. "The SWANCC decision and its implications for prairie potholes." Wetlands 23.3 (2003): 590-596. Wu, Tong, Qiu Gan, and Urs Jans. "Nucleophilic Substitution of Phosphorothionate Ester Pesticides with Bisulfide (HS-) and Polysulfides (Sn2-)." Environmental science & technology 40.17 (2006): 5428-5434. Zeng, Teng, et al. "Pesticide processing potential in prairie pothole porewaters."Environmental science & technology 45.16 (2011): 6814-6822. Zeng, Teng, Yu-Ping Chin, and William

  6. Adsorption and desorption of chlorpyrifos to soils and sediments.

    PubMed

    Gebremariam, Seyoum Yami; Beutel, Marc W; Yonge, David R; Flury, Markus; Harsh, James B

    2012-01-01

    Chlorpyrifos, one of the most widely used insecticides, has been detected in air, rain, marine sediments, surface waters, drinking water wells, and solid and liquid dietary samples collected from urban and rural areas. Its metabolite, TCP, has also been widely detected in urinary samples collected from people of various age groups. With a goal of elucidating the factors that control the environmental contamination, impact, persistence, and ecotoxicity of chlorpyrifos, we examine, in this review, the peer-reviewed literature relating to chlorpyrifos adsorption and desorption behavior in various solid-phase matrices. Adsorption tends to reduce chlorpyrifos mobility, but adsorption to erodible particulates, dissolved organic matter, or mobile inorganic colloids enhances its mobility. Adsorption to suspended sediments and particulates constitutes a major off-site migration route for chlorpyrifos to surface waters, wherein it poses a potential danger to aquatic organisms. Adsorption increases the persistence of chlorpyrifos in the environment by reducing its avail- ability to a wide range of dissipative and degradative forces, whereas the effect of adsorption on its ecotoxicity is dependent upon the route of exposure. Chlorpyrifos adsorbs to soils, aquatic sediments, organic matter, and clay minerals to differing degrees. Its adsorption strongly correlates with organic carbon con- tent of the soils and sediments. A comprehensive review of studies that relied on the batch equilibrium technique yields mean and median Kd values for chlorpyrifos of 271 and 116 L/kg for soils, and 385 and 403 L/kg for aquatic sediments. Chlorpyrifos adsorption coefficients spanned two orders of magnitude in soils. Normalizing the partition coefficient to organic content failed to substantially reduce variability to commonly acceptable level of variation. Mean and median values for chlorpyrifos partition coefficients normalized to organic carbon, K, were 8,163 and 7,227 L/kg for soils and 13

  7. An observational study of the potential for human exposures to pet-borne diazinon residues following lawn applications

    SciTech Connect

    Morgan, Marsha K. Stout, Daniel M.; Jones, Paul A.; Barr, Dana B.

    2008-07-15

    This study examined the potential for pet dogs to be an important pathway for transporting diazinon residues into homes and onto its occupants following residential lawn applications. The primary objectives were to investigate the potential exposures of occupants and their pet dogs to diazinon after an application to turf at their residences and to determine if personal contacts between occupants and their pet dogs resulted in measurable exposures. It was conducted from April to August 2001 before the Agency phased out all residential uses of diazinon in December 2004. Six families and their pet dogs were recruited into the study. Monitoring was conducted at pre-, 1, 2, 4, and 8 days post-application of a commercial, granular formulation of diazinon to the lawn by the homeowner. Environmental samples collected included soil, indoor air, carpet dust, and transferable residues from lawns and floors. Samples collected from the pet dogs consisted of paw wipes, fur clippings, and transferable residues from the fur by a technician or child wearing a cotton glove(s). First morning void (FMV) urine samples were collected from each child and his/her parent on each sampling day. Diazinon was analyzed in all samples, except urine, by GC-MS. The metabolite 2-isopropyl-4-methyl-6-hydroxypyrimidine (IMPy) was analyzed in the urine samples by HPLC-MS/MS. Mean airborne residues of diazinon on day 1 post-application were at least six times higher in both the living rooms (235{+-}267 ng/m{sup 3}) and children's bedrooms (179{+-}246 ng/m{sup 3}) than at pre-application. Mean loadings of diazinon in carpet dust samples were at least 20 times greater on days 2, 4, and 8 post-application than mean loadings (0.03{+-}0.04 ng/cm{sup 2}) at pre-application. The pet dogs had over 900 times higher mean loadings of diazinon residues on their paws on day 1 post-application (88.1{+-}100.1 ng/cm{sup 2}) compared to mean loadings (<0.09 ng/cm{sup 2}) at pre-application. The mean diazinon loadings

  8. Sensitive impedimetric biosensor for direct detection of diazinon based on lipases

    NASA Astrophysics Data System (ADS)

    Jaffrezic-Renault, Nicole; Zehani, Nedjla; Dzyadevych, Sergei; Kherrat, Rochdi

    2014-07-01

    Two novel impedimetric biosensors for highly sensitive and rapid quantitative detection of diazinon in an aqueous medium were developed using two types of lipase, from Candida Rugosa (microbial source) (CRL) and from porcine pancreas (animal source) (PPL) immobilized onto a functionalized gold electrode. The lipase is characterized to specifically catalyze the hydrolysis of ester functions leading to the transformation of diazinon into diethyl phosphorothioic acid (DETP) and 2-isopropyl-4-methyl-6-hydroxypyrimidine (IMHP). The developed biosensors both presented a large wide range of linearity up to 50µM with a detection limit of 10 nM for the CRL biosensor and 0.1 µM for the PPL biosensor. A comparative study was carried out between the two biosensors and results showed higher sensitivity for the CRL sensor. Moreover, it presented good accuracy and reproducibility, and had very good storage and multiple use stability for 25 days when stored at 4°C.

  9. Acute toxicity of diazinon is similar for eight stocks of bobwhite

    USGS Publications Warehouse

    Hill, E.F.; Camardese, M.B.; Heinz, G.H.; Spann, J.W.; DeBevec, A.B.

    1984-01-01

    Nine-week-old bobwhite (Colinus virginianus) from eight different game farms were tested for their sensitivity to an acute oral exposure of technical-grade diazinon (phosphorothioic acid O, O-diethyl-O-[6-methyl- 2-(1 -methylethy 1)-4-pyrimidinyl]ester). Extraneous variables associated with interlaboratory differences in husbandry were eliminated by incubating eggs and rearing chicks to test age for all stocks simultaneously in the same facilities at the Patuxent Wildlife Research Center. Under this single set of conditions, the responses of the eight stocks of bobwhite to diazinon were statistically inseparable, with LD50 values varying from 13 mg/kg (95% confidence interval, 8-21 mg/kg) to 17 mg/kg (95% confidence interval, 11-25 mg/kg). The pooled LD50 for the eight stocks was 14.7 mg/kg (95% confidence interval,13.1-16.5 mg/kg).

  10. Survival and behavioral responses of larvae of the caddis fly Hydropsyche angustipennis to copper and diazinon

    SciTech Connect

    Geest, H.G. van der; Greve, G.D.; Haas, E.M. De; Scheper, B.B.; Kraak, M.H.S.; Stuijfzand, S.C.; Augustijn, K.H.; Admiraal, W.

    1999-09-01

    This study reports on newly developed short-term survival and behavioral tests with larvae of the caddis fly Hydropsyche angustipennis using two model toxicants, copper and diazinon. Mortality of first instar larvae was shown to be a reliable endpoint, and it was demonstrated that H. angustipennis is among the more sensitive aquatic insects in terms of both copper and diazinon. In addition, short-term behavioral responses were found to be indicative of adverse effects of ecologically relevant low doses of copper. Using the tests developed in this study, hydropsychid species are excellent tools for discerning the effects of individual toxicants present in large European rivers, and these species may help in defining the conditions for ecological rehabilitation.

  11. Sensitive impedimetric biosensor for direct detection of diazinon based on lipases

    PubMed Central

    Zehani, Nedjla; Dzyadevych, Sergei V.; Kherrat, Rochdi; Jaffrezic-Renault, Nicole J.

    2014-01-01

    Two novel impedimetric biosensors for highly sensitive and rapid quantitative detection of diazinon in aqueous medium were developed using two types of lipase, from Candida Rugosa (microbial source) (CRL) and from porcine pancreas (animal source) (PPL) immobilized on functionalized gold electrode. Lipase is characterized to specifically catalyze the hydrolysis of ester functions leading to the transformation of diazinon into diethyl phosphorothioic acid (DETP) and 2-isopropyl-4-methyl-6-hydroxypyrimidine (IMHP). The developed biosensors both presented a wide range of linearity up to 50 μM with a detection limit of 10 nM for Candida Rugosa biosensor and 0.1 μM for porcine pancreas biosensor. A comparative study was carried out between the two biosensors and results showed higher efficiency of Candida Rugosa sensor. Moreover, it presented good accuracy and reproducibility, had very good storage and multiple use stability for 25 days when stored at 4°C. PMID:25072052

  12. Oxidative damage in gills and liver in Nile tilapia (Oreochromis niloticus) exposed to diazinon.

    PubMed

    Toledo-Ibarra, G A; Díaz Resendiz, K J G; Ventura-Ramón, G H; González-Jaime, F; Vega-López, A; Becerril-Villanueva, E; Pavón, L; Girón-Pérez, M I

    2016-10-01

    Agricultural activity demands the use of pesticides for plague control and extermination. In that matter, diazinon is one of the most widely used organophosphorus pesticides (OPs). Despite its benefits, the use of OPs in agricultural activities can also have negative effects since the excessive use of these substances can represent a major contamination problem for water bodies and organisms that inhabit them. The aim of this paper was to evaluate oxidative damage in lipids and proteins of Nile tilapia (Oreochromis niloticus) exposed acutely to diazinon (0.97, 1.95 and 3.95ppm) for 12 or 24h. The evaluation of oxidative damage was determined by quantifying lipid hydroperoxides (Fox method) and oxidized proteins (DNPH method). The data from this study suggest that diazinon induces a concentration-dependent oxidative damage in proteins, but not lipids, of the liver and gills of Nile tilapia. Furthermore, the treatment leads to a decrease in the concentration of total proteins, which can have serious consequences in cell physiology and fish development.

  13. Oxidative damage in gills and liver in Nile tilapia (Oreochromis niloticus) exposed to diazinon.

    PubMed

    Toledo-Ibarra, G A; Díaz Resendiz, K J G; Ventura-Ramón, G H; González-Jaime, F; Vega-López, A; Becerril-Villanueva, E; Pavón, L; Girón-Pérez, M I

    2016-10-01

    Agricultural activity demands the use of pesticides for plague control and extermination. In that matter, diazinon is one of the most widely used organophosphorus pesticides (OPs). Despite its benefits, the use of OPs in agricultural activities can also have negative effects since the excessive use of these substances can represent a major contamination problem for water bodies and organisms that inhabit them. The aim of this paper was to evaluate oxidative damage in lipids and proteins of Nile tilapia (Oreochromis niloticus) exposed acutely to diazinon (0.97, 1.95 and 3.95ppm) for 12 or 24h. The evaluation of oxidative damage was determined by quantifying lipid hydroperoxides (Fox method) and oxidized proteins (DNPH method). The data from this study suggest that diazinon induces a concentration-dependent oxidative damage in proteins, but not lipids, of the liver and gills of Nile tilapia. Furthermore, the treatment leads to a decrease in the concentration of total proteins, which can have serious consequences in cell physiology and fish development. PMID:27174646

  14. Simultaneous determination of carbaryl, malathion, fenitrothion, and diazinon residues in sesame seeds (Sesamum indicum L.).

    PubMed

    Gebreegzi, Y T; Foster, G D; Khan, S U

    2000-11-01

    A method is described for the simultaneous determination of carbaryl (1-naphthyl methylcarbamate), malathion [diethyl (dimethoxythiophosphorylthio) succinate], fenitrothion (O,O-dimethyl O-4-nitro-m-tolyl phosphorothioate), and diazinon (O,O-diethyl O-2-isopropyl-6-methylpyrimidin-4-yl phosphorothioate) in sesame (Sesamum indicum L.) seeds. Sesame seeds were Soxhlet extracted with n-hexane, and the extract was subjected to a liquid-liquid partitioning and column cleanup to remove the oily coextractives prior to analysis by high performance liquid chromatography (HPLC). The mean percent recoveries (+/- standard deviations) from sesame seeds fortified with carbaryl (0.004 to 0.035 microgram/g), malathion (0.53 to 4.25 microgram/g), fenitrothion (0.22 to 1.78 microgram/g), and diazinon (0.54 to 4.35 microgram/g) were 83.3 +/- 5.7, 85.5 +/- 6.6, 85. 6 +/- 7.2, and 88.4 +/- 4.8, respectively. The method was used for the simultaneous analysis of carbaryl, malathion, fenitrothion, and diazinon residues in sesame seeds obtained from an Ethiopian field crop that had been treated with the pesticides during its growing period.

  15. Square wave adsorptive stripping voltammetric determination of diazinon in its insecticidal formulations.

    PubMed

    Guziejewski, Dariusz; Skrzypek, Sławomira; Ciesielski, Witold

    2012-11-01

    The pesticide diazinon was determined in its insecticidal formulations by square wave adsorptive stripping voltammetry. The method of its determination is based on the irreversible reduction reaction at the hanging mercury drop electrode. The optimal signal was detected at -1.05 V vs. Ag/AgCl in Britton-Robinson buffer at pH 4.4. Various parameters such as pH, buffer concentration, frequency, amplitude, step potential, accumulation time, and potential were investigated to enhance the sensitivity of the determination. The highest response was recorded at an accumulation potential -0.4 V, accumulation time 60 s, amplitude 75 mV, frequency 100 Hz, and step potential 5 mV. The pesticide electrochemical behavior was considered under experimental conditions. The electroanalytical procedure enabled diazinon determination in the concentration range 4.0 × 10(-8)-3.9 × 10(-7) mol L(-1) in supporting electrolyte. The detection and quantification limit were found to be 1.1 × 10(-8) and 3.7 × 10(-8) mol L(-1), respectively. The method was applied successfully in the determination of the active ingredients in the insecticidal formulations Diazinon 10GR and Beaphar 275.

  16. Does thyroid disruption contribute to the developmental neurotoxicity of chlorpyrifos?

    PubMed

    Slotkin, Theodore A; Cooper, Ellen M; Stapleton, Heather M; Seidler, Frederic J

    2013-09-01

    Although organophosphate pesticides are not usually characterized as "endocrine disruptors," recent work points to potential, long-term reductions of circulating thyroid hormones after developmental exposures to chlorpyrifos that are devoid of observable toxicity. We administered chlorpyrifos to developing rats on gestational days 17-20 or postnatal days 1-4, regimens that produce distinctly different, sex-selective effects on neurobehavioral performance. The prenatal regimen produced a small, but statistically significant reduction in brain thyroxine levels from juvenile stages through adulthood; in contrast, postnatal exposure produced a transient elevation in young adulthood. However, in neither case did we observe the sex-selectivity noted earlier for neurobehavioral outcomes of these specific treatment regimens, or as reported earlier for effects on serum T4 in developing mice. Thus, although chlorpyrifos has the potential to disrupt thyroid status sufficiently to alter brain thyroid hormone levels, the effect is small, and any potential contribution to neurobehavioral abnormalities remains to be proven. PMID:23686008

  17. Genotoxicity of chlorpyrifos and cypermethrin to ICR mouse hepatocytes.

    PubMed

    Cui, Yong; Guo, Jiangfeng; Xu, Bujin; Chen, Ziyuan

    2011-01-01

    Massive application of pesticides had generated a considerable concern in the public. Potentials of chlorpyrifos [O,O-diethyl-O-(3,5,6-trichloro-2-pyridinyl) phosphorothionate] and cypermethrin [(RS)-α-cyano-3-phenoxybenzyl (1RS)-cis-trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate] to induce the excision-repairable DNA damage, DNA strand breakage, and DNA hypomethylation in ICR mouse hepatocytes were investigated. It was showed that chlorpyrifos and cypermethrin didn't increase the incorporation of (3)H-TdR into DNA of ICR mouse hepatocytes but increased the frequency of comet cells and decreased the 5MeC percentage of ICR mouse hepatocytes. In conclusion, chlorpyrifos and cypermethrin induced no excision-repairable DNA damage but led to DNA strand breakage and DNA hypomethylation in ICR mouse hepatocytes.

  18. An evaluation of alternative insecticides to diazinon for control of tephritid fruit flies (Diptera: Tephritidae) in soil.

    PubMed

    Stark, John D; Vargas, Roger

    2009-02-01

    Diazinon has been used extensively in the past as part of California eradication programs for tephritid fruit flies (Diptera: Tephritidae) as a soil drench, but it is being phased out for this purpose in the United States. Therefore, in this study, the toxicity of Platinum, Force, Admire, Regent, and Warrior was estimated after application to sand and soil as drenches for control of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann); melon fly, Bactrocera cucurbitae (Coquillett); and oriental fruit fly, Bactrocera dorsalis (Hendel), in Hawaii. Susceptibility of each species differed. In sand, the order of toxicity at LC50 based on the 95% confidence limit overlap approach for C. capitata from most toxic to least toxic was diazinon > Force = Warrior > Admire = Platinum > Regent. The order of toxicity for B. dorsalis was diazinon > Platinum = Warrior = Force > Regent = Admire. The order of toxicity for B. cucurbitae was Warrior = diazinon > Force = Regent = Platinum = Admire. Based on the dose ratio method, Warrior was not significantly different at LC50 than diazinon for B. cucurbitae only. All other insecticides were significantly different from diazinon at LC50. Studies in sand were followed by an evaluation of specific concentrations of Warrior and Force in soil collected from two sites on the island of Kauai. Average concentrations that caused at least 95% mortality in soil in all three fruit fly species were 121 g active ingredient (AI)/ha for Force and 363 g (AI)/ha for Warrior compared with 182 g (AI)/ha for diazinon. These results indicate that Force and Warrior could be used as soil treatments for control of tephritid fruit flies.

  19. Biodegradation of chlorpyrifos by bacterial consortium isolated from agriculture soil.

    PubMed

    Sasikala, Chitrambalam; Jiwal, Sonia; Rout, Pallabi; Ramya, Mohandass

    2012-03-01

    Organophosphorous pesticides are widely used in agriculture to control major insect pests. Chlorpyrifos is one of the major organophosphorous pesticides which is used to control insects including termites, beetles. The widespread use of these pesticides is hazardous to the environment and also toxic to mammals, thus it is essential to remove the same from the environment. From the chlorpyrifos contaminated soil nine morphologically different bacterial strains, one actinomycete and two fungal strains were isolated. Among those isolates four bacterial strains which were more efficient were developed as consortium. The four bacterial isolates namely Pseudomonas putida (NII 1117), Klebsiella sp., (NII 1118), Pseudomonas stutzeri (NII 1119), Pseudomonas aeruginosa (NII 1120) present in the consortia were identified on the basis of 16S rDNA analysis. The intracellular fractions of the consortium exhibited more organophosphorus hydrolase activity (0.171 ± 0.003 U/mL/min). The degradation studies were carried out at neutral pH and temperature 37°C with chlorpyrifos concentration 500 mg L(-1). LC-mass spectral analysis showed the presence of metabolites chlopyrifos-oxon and Diethylphosphorothioate. These results highlight an important potential use of this consortium for the cleanup of chlorpyrifos contaminated pesticide waste in the environment.

  20. MODELING AGGREGATE CHLORPYRIFOS EXPOSURE AND DOSE TO CHILDREN

    EPA Science Inventory

    To help address the aggregate exposure assessment needs of the Food Quality Protection Act, a physically-based probabilistic model (SHEDS-Pesticides, version 3) has been applied to estimate aggregate chlorpyrifos exposure and dose to children. Two age groups (0-4, 5-9 years) a...

  1. Risk assessment under FQPA: case study with chlorpyrifos.

    PubMed

    Clevelan, C B; Oliver, G R; Chen, B; Mattsson, J

    2001-10-01

    Key science policies have had significant impact on the evolving implementation of the Food Quality and Protection Act (FQPA) (PL 104-170, 1996) by the US Environmental Protection Agency (EPA). The impact offour of these policies will be examined using the risk assessment for chlorpyrifos as a case study. These policies are selection of a regulatory endpoint, use of animal data without consideration of human data for setting the reference dose, a 10 FQPA safety factor and use of the 99.9 percentile of modeled consumer exposure in the acute dietary assessment. Each of these policy decisions had individual impact that was then compounded as cumulative impact on the revised risk assessment for chlorpyrifos conducted by the US EPA in 2000 [Federal Register Notice 65(159) (2000) 49982]. But embedded within each science policy, there are assumptions which may be too conservative and which together have resulted in a very large multiplicative reduction in the allowable exposure limits for chlorpyrifos in the US. These new exposure limits are quite different from other regulatory standards around the world. There is third party opposition to many of these policies and many believe the understanding of the relationship between exposure and what is known about human and animal responses to chlorpyrifos has been clouded. These changes in policy insert a new level of conservatism into the scientific statement of risk and create confusion that threatens to weaken the credibility of the regulatory process. PMID:11770891

  2. Neurologic function among termiticide applicators exposed to chlorpyrifos.

    PubMed Central

    Steenland, K; Dick, R B; Howell, R J; Chrislip, D W; Hines, C J; Reid, T M; Lehman, E; Laber, P; Krieg, E F; Knott, C

    2000-01-01

    Chlorpyrifos is a moderately toxic organophosphate pesticide. Houses and lawns in the United States receive a total of approximately 20 million annual chlorpyrifos treatments, and 82% of U.S. adults have detectable levels of a chlorpyrifos metabolite (3,5, 6-trichloro-2-pyridinol; TCP) in the urine. The U.S. Environmental Protection Agency has estimated that there are 5,000 yearly reported cases of accidental chlorpyrifos poisoning, and approximately one-fourth of these cases exhibit symptoms. Organophosphates affect the nervous system, but there are few epidemiologic data on chlorpyrifos neurotoxicity. We studied neurologic function in 191 current and former termiticide applicators who had an average of 2.4 years applying chlorpyrifos and 2.5 years applying other pesticides, and we compared them to 189 nonexposed controls. The average urinary TCP level for 65 recently exposed applicators was 629.5 microg/L, as compared to 4.5 microg/L for the general U.S. population. The exposed group did not differ significantly from the nonexposed group for any test in the clinical examination. Few significant differences were found in nerve conduction velocity, arm/hand tremor, vibrotactile sensitivity, vision, smell, visual/motor skills, or neurobehavioral skills. The exposed group did not perform as well as the nonexposed group in pegboard turning tests and some postural sway tests. The exposed subjects also reported significantly more symptoms, including memory problems, emotional states, fatigue, and loss of muscle strength; our more quantitative tests may not have been adequate to detect these symptoms. Eight men who reported past chlorpyrifos poisoning had a pattern of low performance on a number of tests, which is consistent with prior reports of chronic effects of organophosphate poisoning. Overall, the lack of exposure effects on the clinical examination was reassuring. The findings for self-reported symptoms raise some concern, as does the finding of low performance

  3. Structural and metabolic responses of microbial community to sewage-borne chlorpyrifos in constructed wetlands.

    PubMed

    Zhang, Dan; Wang, Chuan; Zhang, Liping; Xu, Dong; Liu, Biyun; Zhou, Qiaohong; Wu, Zhenbin

    2016-06-01

    Long-term use of chlorpyrifos poses a potential threat to the environment that cannot be ignored, yet little is known about the succession of substrate microbial communities in constructed wetlands (CWs) under chlorpyrifos stress. Six pilot-scale CW systems receiving artificial wastewater containing 1mg/L chlorpyrifos were established to investigate the effects of chlorpyrifos and wetland vegetation on the microbial metabolism pattern of carbon sources and community structure, using BIOLOG and denaturing gradient gel electrophoresis (DGGE) approaches. Based on our samples, BIOLOG showed that Shannon diversity (H') and richness (S) values distinctly increased after 30days when chlorpyrifos was added. At the same time, differences between the vegetated and the non-vegetated systems disappeared. DGGE profiles indicated that H' and S had no significant differences among four different treatments. The effect of chlorpyrifos on the microbial community was mainly reflected at the physiological level. Principal component analysis (PCA) of both BIOLOG and DGGE showed that added chlorpyrifos made a difference on test results. Meanwhile, there was no difference between the vegetation and no-vegetation treatments after addition of chlorpyrifos at the physiological level. Moreover, the vegetation had no significant effect on the microbial community at the genetic level. Comparisons were made between bacteria in this experiment and other known chlorpyrifos-degrading bacteria. The potential chlorpyrifos-degrading ability of bacteria in situ may be considerable.

  4. Modifying Effects of Vitamin E on Chlorpyrifos Toxicity in Atlantic Salmon

    PubMed Central

    Olsvik, Pål A.; Berntssen, Marc H. G.; Søfteland, Liv

    2015-01-01

    The aim of this study was to elucidate how vitamin E (alpha tocopherol) may ameliorate the toxicity of the pesticide chlorpyrifos in Atlantic salmon. Freshly isolated hepatocytes were exposed to vitamin E, chlorpyrifos or a combination of vitamin E and chlorpyrifos (all 100 μM). Transcriptomics (RNA-seq) and metabolomics were used to screen for effects of vitamin E and chlorpyrifos. By introducing vitamin E, the number of upregulated transcripts induced by chlorpyrifos exposure was reduced from 941 to 626, while the number of downregulated transcripts was reduced from 901 to 742 compared to the control. Adding only vitamin E had no effect on the transcriptome. Jak-STAT signaling was the most significantly affected pathway by chlorpyrifos treatment according to the transcriptomics data. The metabolomics data showed that accumulation of multiple long chain fatty acids and dipeptides and amino acids in chlorpyrifos treated cells was partially alleviated by vitamin E treatment. Significant interaction effects between chlorpyrifos and vitamin E were seen for 15 metabolites, including 12 dipeptides. The antioxidant had relatively modest effects on chlorpyrifos-induced oxidative stress. By combining the two data sets, the study suggests that vitamin E supplementation prevents uptake and accumulation of fatty acids, and counteracts inhibited carbohydrate metabolism. Overall, this study shows that vitamin E only to a moderate degree modifies chlorpyrifos toxicity in Atlantic salmon liver cells. PMID:25774794

  5. Structural and metabolic responses of microbial community to sewage-borne chlorpyrifos in constructed wetlands.

    PubMed

    Zhang, Dan; Wang, Chuan; Zhang, Liping; Xu, Dong; Liu, Biyun; Zhou, Qiaohong; Wu, Zhenbin

    2016-06-01

    Long-term use of chlorpyrifos poses a potential threat to the environment that cannot be ignored, yet little is known about the succession of substrate microbial communities in constructed wetlands (CWs) under chlorpyrifos stress. Six pilot-scale CW systems receiving artificial wastewater containing 1mg/L chlorpyrifos were established to investigate the effects of chlorpyrifos and wetland vegetation on the microbial metabolism pattern of carbon sources and community structure, using BIOLOG and denaturing gradient gel electrophoresis (DGGE) approaches. Based on our samples, BIOLOG showed that Shannon diversity (H') and richness (S) values distinctly increased after 30days when chlorpyrifos was added. At the same time, differences between the vegetated and the non-vegetated systems disappeared. DGGE profiles indicated that H' and S had no significant differences among four different treatments. The effect of chlorpyrifos on the microbial community was mainly reflected at the physiological level. Principal component analysis (PCA) of both BIOLOG and DGGE showed that added chlorpyrifos made a difference on test results. Meanwhile, there was no difference between the vegetation and no-vegetation treatments after addition of chlorpyrifos at the physiological level. Moreover, the vegetation had no significant effect on the microbial community at the genetic level. Comparisons were made between bacteria in this experiment and other known chlorpyrifos-degrading bacteria. The potential chlorpyrifos-degrading ability of bacteria in situ may be considerable. PMID:27266297

  6. Circadian Rhythmicity of Diazinon Susceptibility, Detoxifying Enzymes, and Energy Reserves in Aphis gossypii (Hemiptera: Aphididae).

    PubMed

    Bagheri, Faezeh; Talebi, Khalil; Hosseininaveh, Vahid; Allahyari, Hossein; Habibi-Rezaei, Mehran; Zare, Shahnaz

    2016-08-01

    The daily susceptibility rhythm of the cotton aphid, Aphis gossypii Glover, to diazinon and the corresponding changes in the activity of three xenobiotic detoxifying enzymes-cytochrome P450 monooxygenases (P450), glutathione S-transferases (GSTs), and esterases-were investigated. Bioassays were conducted to estimate the median lethal doses (LD50) of diazinon at six different zeitgeber times (ZT0, 4, 8, 12, 16, and 20) under constant light (LL) and lighting conditions of 16 h of light and 8 h of darkness (LD). The results showed that the highest susceptibility occurred at the onset of night (ZT16) and 4 h before this time point (ZT12) under the LD condition. The endogenous rhythmicity of susceptibility was ensured, as the highest susceptibility occurred at the same time under the LL condition. The circadian changes in susceptibility to diazinon were almost coincident with changes in esterase and GSTs activity, but not in P450 activity. We also found rhythmic changes in energy components of whole-body aphids, with similar patterns of circadian changes of proteins, lipids, and soluble carbohydrates, but not glycogen, under LL and LD conditions. These photoperiod conditions (LD and LL) showed different fluctuation in trends of energy resources and of course, different quantities. Our study represents the first report of circadian control of insecticide susceptibility in aphids and provides insights into more efficient control of these pests by unveiling the times of day during which aphids are more susceptible to insecticides with attention to endogenous physiological phenomena. PMID:27298427

  7. Examining the joint toxicity of chlorpyrifos and atrazine in the aquatic species: Lepomis macrochirus, Pimephales promelas and Chironomus tentans.

    PubMed

    Tyler Mehler, W; Schuler, Lance J; Lydy, Michael J

    2008-03-01

    The joint toxicity of chlorpyrifos and atrazine was compared to that of chlorpyrifos alone to discern any greater than additive response using both acute toxicity testing and whole-body residue analysis. In addition, acetylcholinesterase (AChE) inhibition and biotransformation were investigated to evaluate the toxic mode of action of chlorpyrifos in the presence of atrazine. The joint toxicity of atrazine and chlorpyrifos exhibited no significant difference in Lepomis macrochirus compared to chlorpyrifos alone; while studies performed with Pimephales promelas and Chironomus tentans, did show significant differences. AChE activity and biotransformation showed no significant differences between the joint toxicity of atrazine and chlorpyrifos and that of chlorpyrifos alone. From the data collected, the combination of atrazine and chlorpyrifos pose little additional risk than that of chlorpyrifos alone to the tested fish species.

  8. Study of the Effects of Diazinon on Fetal Liver in BALB/c Mice

    PubMed Central

    Saraei, Fatemeh; Sadoughi, Mehrangiz; Kaka, Gholamreza; Sadraie, Seyed Homayoon; Foaddodini, Mohsen

    2016-01-01

    Background Diazinon is an organophosphate that is broadly used as a pesticide to control insects and environmental pollutions. This toxic material is absorbed via inhalation, contact, or digestion and affects different tissues. Objectives This research was a histomorphometric and immunohistochemical study of the fetal liver of mice after exposure to Diazinon. Materials and Methods Twenty-five pregnant BALB/c mice (25 - 30 gr) were divided into five equal groups in the animal lab of Baqiyatallah University of Medical Sciences, Tehran, Iran. The normal group was without any intervention, and two sham groups received an emulsifier as 0.52 and 5.2 μL/volume (5000 cc in desiccator) and two experimental groups received Diazinon 1.3 and 13μL/volume from the seventh to eighteenth days of pregnancy every other day via forty minutes of inhalation. The pregnant mice were killed on the eighteenth day of gestation and their fetuses were removed and evaluated for fetal growth and liver development. Five fixed fetuses were dehydrated through a series of graded ethanol, embedded in paraffin wax and their whole bodies were sectioned sagittally and stained via the hematoxylin-eosin method. Quantitative computer-assisted morphometric studies were done on the fetal liver tissues occupied by hepatocytes, blood islands, liver sinusoids, and apoptosis. Results The mean crown-rump of the fetuses and their mean weight were increased in the experimental group as compared to the sham and normal groups, but the differences were not significant. The mean percentage of the hepatocyte area significantly increased in the experimental group as compared to the sham and control groups (P < 0.0001). However, the mean sinusoid area significantly decreased in the experimental group as compared to the sham and control groups. The mean percentage of the area occupied by apoptotic hepatocytes in the experimental group - 13 μL /volume (8.6143 ± 1.00945) and 1.3 μL /volume (6.1091 ± 0

  9. Effects of storage and processing on residue levels of chlorpyrifos in soybeans.

    PubMed

    Zhao, Liuwei; Ge, Jing; Liu, Fengmao; Jiang, Naiwen

    2014-05-01

    The residue levels of chlorpyrifos in soybeans during storage and processing were investigated. Soybeans were treated with chlorpyrifos aqueous solution and placed in a sealed plastic container. The residue of chlorpyrifos was determined in soybeans at six time points within 0 and 112days during storage and oil processing of the soybeans was conducted. The analysis of the residues of chlorpyrifos was carried out by gas chromatography-mass spectrometry (GC-MS). Results show that the dissipation of chlorpyrifos in soybeans is about 62% during the storage period. Moreover, the carryover of the residues from soybeans into oil is found to be related to the processing methods. Processing factor, which is defined as the ratio of chlorpyrifos residue concentration in oil sample to that in the soybean samples, was 11 and 0.25 after cold and hot pressing, respectively.

  10. Application of pesticide transport model for simulating diazinon runoff in California’s central valley

    NASA Astrophysics Data System (ADS)

    Joyce, Brian A.; Wallender, Wesley W.; Mailapalli, Damodhara R.

    2010-12-01

    Dormant spray application of pesticides to almond and other stone fruit orchards is the main source of diazinon during the winter in California's central valley. Understanding the pesticide transport and the tradeoffs associated with the various management practices is greatly facilitated by the use of physically-based contaminant transport models. In this study, performance of Joyce's et al. (2008) pesticide transport model was evaluated using experimental data collected from two ground treatments such as resident vegetation and bare soil. The model simulation results obtained in calibration and validation process were analyzed for pesticide concentration and total load. The pesticide transport model accurately predicted the pesticide concentrations and total load in the runoff from bare field and was capable of simulating chemical responses to rainfall-runoff events. In case of resident vegetation, the model results exhibited a larger range of variation than was observed in the bare soil simulations due to increased model parameterization with the addition of foliage and thatch compartments. Furthermore, the model was applied to study the effect of runoff lag time, extent of crop cover, organic content of soil and post-application irrigation on the pesticide peak concentration and total load. Based on the model results, recommendations were suggested to growers prior to implementing certain management decisions to mitigate diazinon transport in the orchard's spray runoff.

  11. Effects of malathion, diazinon, and parathion on mallard embryo development and cholinesterase activity

    USGS Publications Warehouse

    Hoffman, D.J.; Eastin, W.C.

    1981-01-01

    The effects of external exposure of mallard (Anas platyrhynchos) eggs to malathion, diazinon, and parathion were examined using formulations and concentrations similar to field applications. Treatment with aqueous emulsion simulated exposure at the rate of 100 gal per acre (153 liters/hectare) with three to six different doses per compound with treatment at 3 and 8 days of embryonic development. Treatment with a nontoxic oil vehicle simulated exposure at the rate of 11 gal per acre (16.8 liters/hectare) with three to six different doses per compound. The order of embryotoxicity on a pounds-per-acre basis was parathion > diazinon > malathion with either vehicle. However, the potential hazard under conditions of up to five times the maximum field level of application was greater for malathion because of the high permissible level of application for malathion on certain crops. Parathion, the most embryotoxic of the three, had the most pronounced effects when an oil vehicle was used, as reflected by an LC50 of about 2 lb of active ingredient per acre, stunted growth, and a high frequency of malformations involving distortion of the axial skeleton, particularly in the cervical region. All three compounds resulted in significant depression of plasma and brain cholinesterase activity, but parathion caused the most depression throughout development, which was still apparent in hatchlings. Treatment with either distilled water or oil vehicle alone did not result in any of these effects seen with organophosphorous insecticides.

  12. Effects of diazinon on the lymphocytic cholinergic system of Nile tilapia fish (Oreochromis niloticus).

    PubMed

    Toledo-Ibarra, G A; Díaz-Resendiz, K J G; Pavón-Romero, L; Rojas-García, A E; Medina-Díaz, I M; Girón-Pérez, M I

    2016-08-01

    Fish rearing under intensive farming conditions can be easily disturbed by pesticides, substances that have immunotoxic properties and may predispose to infections. Organophosphorus pesticides (OPs) are widely used in agricultural activities; however, the mechanism of immunotoxicity of these substances is unclear. The aim of this study was to evaluate the effect of diazinon pesticides (OPs) on the cholinergic system of immune cells as a possible target of OP immunotoxicity. We evaluated ACh levels and cholinergic (nicotinic and muscarinic) receptor concentration. Additionally, AChE activity was evaluated in mononuclear cells of Nile tilapia (Oreochromis niloticus), a freshwater fish mostly cultivated in tropical regions around the world. The obtained results indicate that acute exposure to diazinon induces an increase in ACh concentration and a decrease in nAChR and mAChR concentrations and AChE activity in fish immune cells, This suggests that the non-neuronal lymphocytic cholinergic system may be the main target in the mechanism of OP immunotoxicity. This study contributes to the understanding of the mechanisms of immunotoxicity of pollutants and may help to take actions for animal health improvement. PMID:27260186

  13. Effects of diazinon on the lymphocytic cholinergic system of Nile tilapia fish (Oreochromis niloticus).

    PubMed

    Toledo-Ibarra, G A; Díaz-Resendiz, K J G; Pavón-Romero, L; Rojas-García, A E; Medina-Díaz, I M; Girón-Pérez, M I

    2016-08-01

    Fish rearing under intensive farming conditions can be easily disturbed by pesticides, substances that have immunotoxic properties and may predispose to infections. Organophosphorus pesticides (OPs) are widely used in agricultural activities; however, the mechanism of immunotoxicity of these substances is unclear. The aim of this study was to evaluate the effect of diazinon pesticides (OPs) on the cholinergic system of immune cells as a possible target of OP immunotoxicity. We evaluated ACh levels and cholinergic (nicotinic and muscarinic) receptor concentration. Additionally, AChE activity was evaluated in mononuclear cells of Nile tilapia (Oreochromis niloticus), a freshwater fish mostly cultivated in tropical regions around the world. The obtained results indicate that acute exposure to diazinon induces an increase in ACh concentration and a decrease in nAChR and mAChR concentrations and AChE activity in fish immune cells, This suggests that the non-neuronal lymphocytic cholinergic system may be the main target in the mechanism of OP immunotoxicity. This study contributes to the understanding of the mechanisms of immunotoxicity of pollutants and may help to take actions for animal health improvement.

  14. Screening and identification of SUMP-proteins in sub-acute treatment with diazinon

    PubMed Central

    Yazdian-Robati, Rezvan; Pourtaji, Atena; Rashedinia, Marzieh; Hosseinzadeh, Hossein; Ghorbani, Maryam; Razavi, BiBi Marjan; Ramezani, Mohammad; Abnous, Khalil

    2015-01-01

    Objective(s): Small ubiquitin-like modifiers (SUMOs) are a family of ubiquitin-related, proteins that are involved in a wide variety of signaling pathways. SUMOylation, as a vital post translational modification, regulate protein function in manycellular processes. Diazinon (DZN), an organophosphate insecticide, causses oxidative stress and subsequently programmed cell death in different tissues. The aim of this study was to evaluate the role and pattern of SUMO modificationas a defense mechanism against stress oxidative, in the heart tissuesof the DZN treated rats. Materials and Methods: Diazinon (15 mg/kg/day), corn oil (control) were administered via gavageto male Wistar rats for four weeks. SUMO1 antibody was covalently crosslinked to protein A/G agarose. heart tissue lysate were added to agarosebeads, After isolation of target proteins(SUMO1- protein)SDS-PAGE gel electrophoresis was performed. Protein bands were identified using MALDI-TOF/TOF and MASCOT). Fold change of (DZN/Ctrl) separated proteins was evaluated using UVband software (UVITEC, UK). Results: Our result showed that subacute exposure to DZN increased SUMOylationoffour key proteins involved in the metabolic process including; Acyl-CoA dehydrogenase, creatine kinase, glyceraldehyde-3-phosphate dehydrogenase and ATP synthase, in the heart tissue of animals. A probability value of less than 0.05 was considered significant (P<0.05). Conclusion: It seems that protein SUMOylation provides a safeguard mechanism against DZN Toxicity. PMID:26877855

  15. Effects of atrazine and cyanazine on chlorpyrifos toxicity in Chironomus tentans (Diptera: Chironomidae).

    PubMed

    Jin-Clark, Ying; Lydy, Michael J; Zhu, Kun Yan

    2002-03-01

    Toxicities of two triazine herbicides (atrazine and cyanazine) and an organophosphate insecticide (chlorpyrifos) were evaluated individually and with each herbicide in binary combination with chlorpyrifos using fourth-instar larvae of the aquatic midge, Chironomus tentans. Chlorpyrifos at 0.25 microg/L resulted in an effect in less than 10% of midges in 48-h acute toxicity bioassays. Neither atrazine nor cyanazine alone at relatively high concentrations (up to 1,000 microg/L) caused significant acute toxicity to C. tentans. However, atrazine and cyanazine caused significant synergistic effects on the toxicity of chlorpyrifos when midges were exposed to mixtures of atrazine or cyanazine (10, 100, 1,000 microg/L) with chlorpyrifos (0.25 microg/L). At fixed concentrations (200 microg/L) of the herbicides, toxicity of chlorpyrifos was enhanced by 1.8- and 2.2-fold by atrazine and cyanazine, respectively, at the 50% effective concentration levels. Although atrazine and cyanazine are not effective inhibitors of acetylcholinesterase (AChE) in vitro, the synergism of the two triazine herbicides with chlorpyrifos was associated with increased in vivo inhibition of AChE in midges. We observed a positive correlation between the degree of inhibition of AChE and the concentration of atrazine or cyanazine in the presence of a fixed concentration of chlorpyrifos. It is possible that these herbicides may affect cytochrome P450 enzymes to confer synergistic effects on the toxicity of chlorpyrifos.

  16. [Thermodynamics adsorption and its influencing factors of chlorpyrifos and triazophos on the bentonite and humus].

    PubMed

    Zhu, Li-Jun; Zhang, Wei; Zhang, Jin-Chi; Zai, De-Xin; Zhao, Rong

    2010-11-01

    The adsorption of chlorpyrifos and triazophos on bentonite and humus was investigated by using the equilibrium oscillometry. The adsorption capacity of chlorpyrifos and triazophos on humus was great higher than bentonite at the same concentration. Equilibrium data of Langmuir, Freundlich isotherms showed significant relationship to the adsorption of chlorpyrifos and triazophos on humus (chlorpyrifos: R2 0.996 4, 0.996 3; triazophos: R2 0.998 9, 0.992 4). Langmuir isotherm was the best for chlorpyrifos and triazophos on bentonite (chlorpyrifos: R2 = 0.995 7, triazophos: R2 = 0.998 9). The pH value, adsorption equilibrium time and temperature were the main factors affecting adsorption of chlorpyrifos and triazophos on bentonite and humus. The adsorption equilibrium time on mixed adsorbent was 12h for chlorpyrifos and 6h for triazophos respectively. The mass ratio of humus and bentonite was 12% and 14% respectively, the adsorption of chlorpyrifos and triazophos was the stronglest and tended to saturation. At different temperatures by calculating the thermodynamic parameters deltaG, deltaH and deltaS, confirmed that the adsorption reaction was a spontaneous exothermic process theoretically. The adsorption was the best when the pH value was 6.0 and the temperature was 15 degrees C.

  17. [Biodegradation mechanism of DDT and chlorpyrifos using molecular simulation].

    PubMed

    Lin, Yu-Zhen; Zeng, Guang-Ming; Zhang, Yu; Chen, Ming; Jiang, Min; Zhang, Jia-Chao; Lu, Lun-Hui; Liu, Li-Feng

    2012-03-01

    In order to explore the microscopic degradation mechanism of organic pesticides degrading enzymes, we used molecular docking method to investigate the binding modes of DDT to laccase and chlorpyrifos to organophosphorus hydrolase, and obtained the corresponding complex structures. According to the principle of minimum scoring, the results showed that the MolDock scores were -103.134 and -111.626, re-rank scores were -72.858 and -80.261, respectively. And we used LPC/CSU server search the interactions between organic pesticides and their degrading enzymes. Our results showed that hydrophobic interaction was the strongest contacts in DDT-laccase complex, and both hydrogen bonds and hydrophobic interactions were the strongest contacts when chlorpyrifos-organophosphorus hydrolase complex. The amino acid residues Tyr224 in laccase and Arg254 in organophosphorus hydrolase were detected to play significant roles in catalytic processes.

  18. Stress proteins hsp60 and hsp70 in three species of amphipods exposed to cadmium, diazinon, dieldrin and fluoranthene

    SciTech Connect

    Werner, I.; Nagel, R.

    1997-11-01

    To investigate the use of stress proteins hsp60 and hsp70 as sublethal biomarkers for contaminant exposure in sediments, two infaunal (Ampelisca abdita, estuarine; Rhepoxynius abronius, marine) and one epifaunal (Hyalella azteca, freshwater) amphipod species were exposed for 24 h to solutions of the heavy metal cadmium, the pesticides diazinon and dieldrin, and the polycyclic aromatic hydrocarbon fluoranthene. All three species are routinely used in standard sediment toxicity tests. Analysis of hsp60 and hsp70 was performed using western blotting techniques with subsequent comparative quantification by densitometry. Results demonstrated compound and species-specific induction of stress protein synthesis. Whereas one member of the hsp70 protein family showed the most sensitive response to xenobiotic compounds in H. azteca, several members of the hsp60 protein family were the main proteins induced in A. abdita and R. abronius. Sensitivity of the detected stress protein response was highest in H. azteca with significant effects at concentrations 110-, 50-, >1,000-, and >1-fold lower than LC50 values for cadmium, diazinon, dieldrin, and fluoranthene, respectively. The corresponding values were >5 (cadmium), 0.7 (diazinon), >1 (dieldrin), and 2.9 (fluoranthene) for A. abdita, and >2 (cadmium), 3.1 (diazinon), > 100 (dieldrin), and >2.9 (fluoranthene) for R. abronius.

  19. Analysis of diazinon pesticide using potentiometric biosensor based on enzyme immobilized cellulose acetate membrane in gold electrode

    NASA Astrophysics Data System (ADS)

    Mashuni; Ramadhan, L. O. A. N.; Jahiding, M.; Herniati

    2016-02-01

    Biosensor for analysis of diazinon pesticide using Potentiometric transducer has been developed. The basic element of this biosensor was a gold electrode modified with an immobilized acetylcholinesterase enzyme layer formed by entrapment with glutaraldehyde crosslinked-cellulose acetate. The aim of the research is to determine the composition of glutaraldehyde crosslinked-cellulose acetate in the gold electrode which provide optimum performance of biosensors of diazinon pesticide analysis on characterization include a range of working concentration, sensitivity, and detection limit. The results showed the composition of the cellulose acetate 15% and glutaraldehyde 25% that obtain optimum performance in the measurement of diazinon pesticide with a range of working concentration of 10-6 ppm to 1 ppm, the value of sensitivity 20.275 mV/decade and detection limit 10-6 ppm. The use of cellulose acetate provides highly sensitive devices allowing the efficient analysis of pesticides. The response time of electrode is on the measurement of pesticide diazinon with concentration variation of 10-6 ppm to 1 ppm with response time is about 5 minutes.

  20. FEASIBILITY STUDY OF THE POTENTIAL FOR HUMAN EXPOSURE TO PET-BORNE DIAZINON RESIDUES FOLLOWING LAWN APPLICATIONS

    EPA Science Inventory

    Diazinon (O,O-diethyl-O-[2-isopropyl-6-methylpyrimidin-4-yl]phosphorothioate) is a broad spectrum organophosphorus insecticide commonly used to control a variety of pest insects (ticks, grubs, ants, and fleas) on lawns (Earl et al. 1971; Tomlin, 1994). Recently, Stout II (1998)...

  1. An Evaluation of Alternative Insecticides to Diazinon for Control of Tephritid Fruit Flies (Diptera: Tephritidae) in Soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diazinon has been used extensively in the past as part of California eradication programs for tephritid fruit flies, but is being phased out for this purpose in the United States. Therefore, in this study, the toxicity of Platinum®, Force®, Admire®, Regent®, and Warrior® was estimated after applica...

  2. PILOT STUDY OF THE POTENTIAL FOR HUMAN EXPOSURES TO PET-BORNE DIAZINON RESIDUES FOLLOWING LAWN APPLICATIONS IN NORTH CAROLINA

    EPA Science Inventory

    This study examined the potential for indoor/outdoor pet dogs to be an important pathway for transporting diazinon residues into homes and onto occupants following residential lawn applications. The primary objective was to investigate the potential exposures of children and thei...

  3. Effects of chlorpyrifos on reproductive performances of guppy (Poecilia reticulata).

    PubMed

    De Silva, P M C S; Samayawardhena, L A

    2005-03-01

    Guppy (Poecilia reticulata) was selected to investigate the effects of chlorpyrifos on reproductive performances. Male and female guppy with proven fertility were selected from our own colony and the groups of fish (n=72/group) were exposed to pre-determined chlorpyrifos concentrations (0.002 microg/l, 2 microg/l) based on the 96-h LC50 for guppy. Mating behavior of males was recorded on the 2nd day of exposure. Offspring were counted and survival recorded on the 14th day. Gonopodial thrusts (8/15 min) in 0.002 microg/l and (4/15 min) in 2 microg/l were significantly different from the control group (11/15 min). Similarly, live birth reduced significantly to 8/female in 2 microg/l compared to 27/female in the control group. Survival of offspring after 14 days was reduced to 47% in the 2 microg/l group compared to 94% of survival in the control. Our findings demonstrate that low soluble concentrations of chlorpyrifos affect mating behavior, number of offspring and offspring survival of guppy.

  4. Sublethal toxicity of chlorpyrifos to salmonid olfaction after hypersaline acclimation.

    PubMed

    Maryoung, Lindley A; Blunt, Brian; Tierney, Keith B; Schlenk, Daniel

    2015-04-01

    Salmonid habitats can be impacted by several environmental factors, such as salinization, which can also affect salmonid tolerance to anthropogenic stressors, such as pesticides. Previous studies have shown that hypersaline acclimation enhances the acute toxicity of certain organophosphate and carbamate pesticides to euryhaline fish; however, sublethal impacts have been far less studied. The current study aims to determine how hypersaline acclimation and exposure to the organophosphate chlorpyrifos (CPF) impact salmonid olfaction. Combined acclimation and exposure to CPF was shown to impact rainbow trout olfaction at the molecular, physiological, and behavioral levels. Concurrent exposure to hypersalinity and 0.5μg/L CPF upregulated four genes (chloride intracellular channel 4, G protein zgc:101761, calcium calmodulin dependent protein kinase II delta, and adrenergic alpha 2C receptor) that inhibit olfactory signal transduction. At the physiological level, hypersalinity and chlorpyrifos caused a decrease in sensory response to the amino acid l-serine and the bile salt taurocholic acid. Combined acclimation and exposure also negatively impacted behavior and reduced the avoidance of a predator cue (l-serine). Thus, acclimation to hypersaline conditions and exposure to environmentally relevant concentrations of chlorpyrifos caused an inhibition of olfactory signal transduction leading to a decreased response to odorants and impairment of olfactory mediated behaviors.

  5. Molecularly imprinted polymer nanoparticles-based electrochemical sensor for determination of diazinon pesticide in well water and apple fruit samples.

    PubMed

    Motaharian, Ali; Motaharian, Fatemeh; Abnous, Khalil; Hosseini, Mohammad Reza Milani; Hassanzadeh-Khayyat, Mohammad

    2016-09-01

    In this research, an electrochemical sensor based on molecularly imprinted polymer (MIP) nanoparticles for selective and sensitive determination of diazinon (DZN) pesticides was developed. The nanoparticles of diazinon imprinted polymer were synthesized by suspension polymerization and then used for modification of carbon paste electrode (CPE) composition in order to prepare the sensor. Cyclic voltammetry (CV) and square wave voltammetry (SWV) methods were applied for electrochemical measurements. The obtained results showed that the carbon paste electrode modified by MIP nanoparticles (nano-MIP-CP) has much higher adsorption ability for diazinon than the CPE based non-imprinted polymer nanoparticles (nano-NIP-CP). Under optimized extraction and analysis conditions, the proposed sensor exhibited excellent sensitivity (95.08 μA L μmol(-1)) for diazinon with two linear ranges of 2.5 × 10(-9) to 1.0 × 10(-7) mol L(-1) (R (2) = 0.9971) and 1.0 × 10(-7) to 2.0 × 10(-6) mol L(-1) (R (2) = 0.9832) and also a detection limit of 7.9 × 10(-10) mol.L(-1). The sensor was successfully applied for determination of diaznon in well water and apple fruit samples with recovery values in the range of 92.53-100.86 %. Graphical abstract Procedure for preparation of electrochemical sensor based on MIP nanoparticles for determination of diazinon.

  6. Molecularly imprinted polymer nanoparticles-based electrochemical sensor for determination of diazinon pesticide in well water and apple fruit samples.

    PubMed

    Motaharian, Ali; Motaharian, Fatemeh; Abnous, Khalil; Hosseini, Mohammad Reza Milani; Hassanzadeh-Khayyat, Mohammad

    2016-09-01

    In this research, an electrochemical sensor based on molecularly imprinted polymer (MIP) nanoparticles for selective and sensitive determination of diazinon (DZN) pesticides was developed. The nanoparticles of diazinon imprinted polymer were synthesized by suspension polymerization and then used for modification of carbon paste electrode (CPE) composition in order to prepare the sensor. Cyclic voltammetry (CV) and square wave voltammetry (SWV) methods were applied for electrochemical measurements. The obtained results showed that the carbon paste electrode modified by MIP nanoparticles (nano-MIP-CP) has much higher adsorption ability for diazinon than the CPE based non-imprinted polymer nanoparticles (nano-NIP-CP). Under optimized extraction and analysis conditions, the proposed sensor exhibited excellent sensitivity (95.08 μA L μmol(-1)) for diazinon with two linear ranges of 2.5 × 10(-9) to 1.0 × 10(-7) mol L(-1) (R (2) = 0.9971) and 1.0 × 10(-7) to 2.0 × 10(-6) mol L(-1) (R (2) = 0.9832) and also a detection limit of 7.9 × 10(-10) mol.L(-1). The sensor was successfully applied for determination of diaznon in well water and apple fruit samples with recovery values in the range of 92.53-100.86 %. Graphical abstract Procedure for preparation of electrochemical sensor based on MIP nanoparticles for determination of diazinon. PMID:27497964

  7. Chlorpyrifos and chlorpyrifos-oxon inhibit axonal growth by interfering with the morphogenic activity of acetylcholinesterase

    SciTech Connect

    Yang Dongren; Howard, Angela; Bruun, Donald; Ajua-Alemanj, Mispa; Pickart, Cecile; Lein, Pamela J.

    2008-04-01

    A primary role of acetylcholinesterase (AChE) is regulation of cholinergic neurotransmission by hydrolysis of synaptic acetylcholine. In the developing nervous system, however, AChE also functions as a morphogenic factor to promote axonal growth. This raises the question of whether organophosphorus pesticides (OPs) that are known to selectively bind to and inactivate the enzymatic function of AChE also interfere with its morphogenic function to perturb axonogenesis. To test this hypothesis, we exposed primary cultures of sensory neurons derived from embryonic rat dorsal root ganglia (DRG) to chlorpyrifos (CPF) or its oxon metabolite (CPFO). Both OPs significantly decreased axonal length at concentrations that had no effect on cell viability, protein synthesis or the enzymatic activity of AChE. Comparative analyses of the effects of CPF and CPFO on axonal growth in DRG neurons cultured from AChE nullizygous (AChE{sup -/-}) versus wild type (AChE{sup +/+}) mice indicated that while these OPs inhibited axonal growth in AChE{sup +/+} DRG neurons, they had no effect on axonal growth in AChE{sup -/-} DRG neurons. However, transfection of AChE{sup -/-} DRG neurons with cDNA encoding full-length AChE restored the wild type response to the axon inhibitory effects of OPs. These data indicate that inhibition of axonal growth by OPs requires AChE, but the mechanism involves inhibition of the morphogenic rather than enzymatic activity of AChE. These findings suggest a novel mechanism for explaining not only the functional deficits observed in children and animals following developmental exposure to OPs, but also the increased vulnerability of the developing nervous system to OPs.

  8. Chlorpyrifos and Chlorpyrifos-Oxon Inhibit Axonal Growth by Interfering with the Morphogenic Activity of Acetylcholinesterase

    PubMed Central

    Yang, Dongren; Howard, Angela; Bruun, Donald; Ajua-Alemanj, Mispa; Pickart, Cecile; Lein, Pamela J.

    2008-01-01

    A primary role of acetylcholinesterase (AChE) is regulation of cholinergic neurotransmission by hydrolysis of synaptic acetylcholine. In the developing nervous system, however, AChE also functions as a morphogenic factor to promote axonal growth. This raises the question of whether organophosphorus pesticides (OPs) that are known to selectively bind to and inactivate the enzymatic function of AChE also interfere with its morphogenic function to perturb axonogenesis. To test this hypothesis, we exposed primary cultures of sensory neurons derived from embryonic rat dorsal root ganglia (DRG) to chlorpyrifos (CPF) or its oxon metabolite (CPFO). Both OPs significantly decreased axonal length at concentrations that had no effect on cell viability, protein synthesis or the enzymatic activity of AChE. Comparative analyses of the effects of CPF and CPFO on axonal growth in DRG neurons cultured from AChE nullizygous (AChE−/−) versus wildtype (AChE+/+) mice indicated that while these OPs inhibited axonal growth in AChE+/+ DRG neurons, they had no effect on axonal growth in AChE−/− DRG neurons. However, transfection of AChE−/− DRG neurons with cDNA encoding full-length AChE restored the wildtype response to the axon inhibitory effects of OPs. These data indicate that inhibition of axonal growth by OPs requires AChE, but the mechanism involves inhibition of the morphogenic rather than enzymatic activity of AChE. These findings suggest a novel mechanism for explaining not only the functional deficits observed in children and animals following developmental exposure to OPs, but also the increased vulnerability of the developing nervous system to OPs. PMID:18076960

  9. Metabolomics reveals energetic impairments in Daphnia magna exposed to diazinon, malathion and bisphenol-A.

    PubMed

    Nagato, Edward G; Simpson, André J; Simpson, Myrna J

    2016-01-01

    (1)H nuclear magnetic resonance (NMR)-based metabolomics was used to study the response of Daphnia magna to increasing sub-lethal concentrations of either an organophosphate (diazinon or malathion) or bisphenol-A (BPA). Principal component analysis (PCA) of (1)H NMR spectra were used to screen metabolome changes after 48h of contaminant exposure. The PCA scores plots showed that diazinon exposures resulted in aberrant metabolomic profiles at all exposure concentrations tested (0.009-0.135 μg/L), while for malathion the second lowest (0.08μg/L) and two highest exposure concentrations (0.32μg/L and 0.47μg/L) caused significant shifts from the control. Individual metabolite changes for both organophosphates indicated that the response to increasing exposure was non-linear and described perturbations in the metabolome that were characteristic of the severity of exposure. For example, intermediate concentrations of diazinon (0.045μg/L and 0.09μg/L) and malathion (0.08μg/L) elicited a decrease in amino acids such as leucine, valine, arginine, glycine, lysine, glutamate, glutamine, phenylalanine and tyrosine, with concurrent increases in glucose and lactate, suggesting a mobilization of energy resources to combat stress. At the highest exposure concentrations for both organophosphates there was evidence of a cessation in metabolic activity, where the same amino acids increased and glucose and lactate decreased, suggesting a slowdown in protein synthesis and depletion of energy stocks. This demonstrated a similar response in the metabolome between two organophosphates but also that intermediate and severe stress levels could be differentiated by changes in the metabolome. For BPA exposures, the PCA scores plot showed a significant change in metabolome at 0.1mg/L, 1.4mg/L and 2.1mg/L of exposure. Individual metabolite changes from 0.7 to 2.1mg/L of BPA exposure showed increases in amino acids such as alanine, valine, isoleucine, leucine, arginine, phenylalanine and

  10. Metabolomics reveals energetic impairments in Daphnia magna exposed to diazinon, malathion and bisphenol-A.

    PubMed

    Nagato, Edward G; Simpson, André J; Simpson, Myrna J

    2016-01-01

    (1)H nuclear magnetic resonance (NMR)-based metabolomics was used to study the response of Daphnia magna to increasing sub-lethal concentrations of either an organophosphate (diazinon or malathion) or bisphenol-A (BPA). Principal component analysis (PCA) of (1)H NMR spectra were used to screen metabolome changes after 48h of contaminant exposure. The PCA scores plots showed that diazinon exposures resulted in aberrant metabolomic profiles at all exposure concentrations tested (0.009-0.135 μg/L), while for malathion the second lowest (0.08μg/L) and two highest exposure concentrations (0.32μg/L and 0.47μg/L) caused significant shifts from the control. Individual metabolite changes for both organophosphates indicated that the response to increasing exposure was non-linear and described perturbations in the metabolome that were characteristic of the severity of exposure. For example, intermediate concentrations of diazinon (0.045μg/L and 0.09μg/L) and malathion (0.08μg/L) elicited a decrease in amino acids such as leucine, valine, arginine, glycine, lysine, glutamate, glutamine, phenylalanine and tyrosine, with concurrent increases in glucose and lactate, suggesting a mobilization of energy resources to combat stress. At the highest exposure concentrations for both organophosphates there was evidence of a cessation in metabolic activity, where the same amino acids increased and glucose and lactate decreased, suggesting a slowdown in protein synthesis and depletion of energy stocks. This demonstrated a similar response in the metabolome between two organophosphates but also that intermediate and severe stress levels could be differentiated by changes in the metabolome. For BPA exposures, the PCA scores plot showed a significant change in metabolome at 0.1mg/L, 1.4mg/L and 2.1mg/L of exposure. Individual metabolite changes from 0.7 to 2.1mg/L of BPA exposure showed increases in amino acids such as alanine, valine, isoleucine, leucine, arginine, phenylalanine and

  11. NEUROBEHAVIORAL EFFECTS OF CHRONIC DIETARY AND REPEATED HIGH-LEVEL SPIKE EXPOSURE TO CHLORPYRIFOS IN RATS.

    EPA Science Inventory

    This study aimed to model long-term subtoxic human exposure to an organophosphorus pesticide, chlorpyrifos, and to examine the influence of that exposure on the response to intermittent high-dose acute challenges. Adult rats were maintained on a chlorpyrifos-containing diet to p...

  12. Binding and detoxification of chlorpyrifos by lactic acid bacteria on rice straw silage fermentation.

    PubMed

    Wang, Yan-Su; Wu, Tian-Hao; Yang, Yao; Zhu, Cen-Ling; Ding, Cheng-Long; Dai, Chuan-Chao

    2016-01-01

    This investigation examined the reduction of pesticide residues on straw inoculated with lactic acid bacteria (LAB) during ensiling. Lactobacillus casei WYS3 was isolated from rice straw that contained pesticide residues. Non-sterilized rice straw, which was inoculated with L. casei WYS3, showed increased removal of chlorpyrifos after ensiling, compared with rice straw that was not inoculated with L. casei WYS3 or sterilized rice straw. In pure culture, these strains can bind chlorpyrifos as indicated by high-performance liquid chromatography analysis. Viable L. casei WYS3 was shown to bind 33.3-42% of exogenously added chlorpyrifos. These results are similar to those of acid-treated cells but less than those of heat-treated cells, which were found to bind 32.0% and 77.2% of the added chlorpyrifos respectively. Furthermore, gas chromatography-mass spectrometry analysis determined that L. casei WYS3 detoxified chlorpyrifos via P-O-C cleavage. Real-time polymerized chain reaction analysis determined that organophosphorus hydrolase gene expression tripled after the addition of chlorpyrifos to LAB cultures, compared with the control group (without chlorpyrifos). This paper highlights the potential use of LAB starter cultures for the detoxification and removal of chlorpyrifos residues in the environment.

  13. Chlorpyrifos-induced hypothermia and vasodilation in the tail of the rat: blockade by scopolamine.

    PubMed

    Gordon, C J; Yang, Y L

    2000-07-01

    Organophosphate pesticides such as chlorpyrifos reduce core temperature (Tc) in laboratory rodents. The mechanism(s) responsible for the chlorpyrifos-induced hypothermia are not well known. This study assessed the role of a key effector for thermoregulation in the rat, vasomotor control of heat loss from the tail, and its possible cholinergic control during chlorpyrifos-induced hypothermia. Tc and motor activity were monitored by telemetry in female Long-Evans rats maintained at an ambient temperature (Ta) of 25 degrees. Tail skin temperature (Tsk(t)) was measured hourly. Rats were dosed with chlorpyrifos (0 or 25 mg/kg orally). Two hr later the rats were dosed with saline or scopolamine (1.0 mg/kg intraperitoneally). Two hr after chlorpyrifos treatment there was a marked elevation in Tsk(t)) concomitant with a 0.5 degrees reduction in Tc. Scopolamine administered to control rats led to a marked elevation in Tc with little change in Tsk(t). Rats treated with chlorpyrifos and administered scopolamine underwent a marked vasoconstriction and elevation in Tc. Vasodilation of the tail is an important thermoeffector to reduce Tc during the acute stages of chlorpyrifos exposure. The blockade of the response by scopolamine suggests that the hypothermic and vasodilatory response to chlorpyrifos is mediated via a cholinergic muscarinic pathway in the CNS. PMID:10987209

  14. BEHAVIORAL AND NEUROCHEMICAL OUTCOMES OF REPEATED ORAL ADMINISTRATION OF CHLORPYRIFOS IN POSTNATAL/JUVENILE RATS.

    EPA Science Inventory

    Concern has been raised regarding potential adverse effects on the nervous system following childhood exposure to chlorpyrifos (O,O-diethyl-O-3,5,6-trichloro-2-pyridyl-phosphorothioate). This study examined the outcomes of daily oral dosing with chlorpyrifos, from early postnata...

  15. Amygdala kindling in immature rats: proconvulsant effect of the organophosphate insecticide-chlorpyrifos.

    PubMed

    Wurpel, J N; Hirt, P C; Bidanset, J H

    1993-01-01

    Administration of the organophosphate insecticide, chlorpyrifos to immature rats exerted a proconvulsant effect on seizures induced by kindling. Chlorpyrifos was administered to 16 or 17 day old rats in a dose range of 0.3 to 10 mg/kg, subcutaneously. Amygdala kindling was performed by stimulating the rats every 15 minutes to a total of 20 stimulations. Kindling occurred more rapidly in the chlorpyrifos treated rats than vehicle treated rats, the proconvulsant effect was dose-dependent. The proconvulsant effect of chlorpyrifos was more pronounced in the early stages of kindling, indicating a possible increase in local excitability of the amygdala in the presence of chlorpyrifos. Chlorpyrifos also reduced the after discharge threshold in the amygdala in a dose-dependent manner and increased the duration of after discharges elicited by electrical stimulus, indicating an increase in excitability of the amygdala. The effects of chlorpyrifos on kindling were additive with xylene: the proconvulsant effect in the early stages of kindling was greatly enhanced by xylene. Xylene, administered alone as a 0.2% solution, reduced the after discharge threshold of the amygdala, increased the after discharge duration and increased the rate of kindling. These experiments demonstrate a proconvulsant effect of chlorpyrifos in amygdala kindling and this proconvulsant action is additive with xylene.

  16. Phytoremediation of chlorpyrifos in aqueous system by riverine macrophyte, Acorus calamus: toxicity and removal rate.

    PubMed

    Wang, Qinghai; Li, Cui; Zheng, Ruilun; Que, Xiaoe

    2016-08-01

    The potential of Acorus calamus to remove chlorpyrifos from water was assessed under laboratory conditions. Toxic effects of the insecticide in A. calamus were evaluated using pulse-amplitude modulated chlorophyll fluorescence techniques as well. At exposure concentrations above 8 mg L(-1), A. calamus showed obvious phytotoxic symptom with significant reduction in quantum efficiency of PSII (ΦPSII) and photochemical quenching coefficient (qP) in 20-day test; the inhibition of maximal quantum efficiency of PSII (Fv/Fm) was accompanied by a significant rise in initial chlorophyll fluorescence (Fo) within 15-day exposures. Fv/Fm and Fo recover to the normal level after 20-day exposure. The reduced removal rate to chlorpyrifos was observed with increase of initial chlorpyrifos concentrations. At application levels of 1, 2, and 4 mg L(-1), the disappearance rate of chlorpyrifos in the hydroponic system with plants was significantly greater than that without plants during the 20-day test periods. Chlorpyrifos was taken up from medium and transferred to above ground tissues by the plant and significant amounts of chlorpyrifos accumulated in plant tissues. The result indicated that A. calamus can promote the disappearance of chlorpyrifos from water and may be used for phytoremediation of water contaminated with a relatively low concentration of chlorpyrifos insecticide (<4 mg L(-1)). PMID:27154841

  17. Inputs of the Dormant-Spray Pesticide, Diazinon, to the San Joaquin River, California, February 1993

    USGS Publications Warehouse

    Domagalski, Joseph L.; Dubrovsky, Neil M.; Kratzer, Charles R.

    1995-01-01

    INTRODUCTION The objective of the National Water Quality Assessment (NAWQA) Program of the U.S. Geological Survey is to describe the status and trends of the Nation's water quality with respect to natural features of the environment and human activities or land-use. Pesticides are a major water-quality issue in the San Joaquin Valley of California (fig. 1), and pesticide residues may be transported to rivers and streams in agricultural runoff following winter storms. Three sites in the western San Joaquin Valley were monitored during and after two February 1993 storms. The storms occurred after extensive spraying of organophosphate insecticides, mostly diazinon, on almond and other stone-fruit orchards.

  18. Identification of a diazinon-metabolizing glutathione S-transferase in the silkworm, Bombyx mori

    PubMed Central

    Yamamoto, Kohji; Yamada, Naotaka

    2016-01-01

    The glutathione S-transferase superfamily play key roles in the metabolism of numerous xenobiotics. We report herein the identification and characterization of a novel glutathione S-transferase in the silkworm, Bombyx mori. The enzyme (bmGSTu2) conjugates glutathione to 1-chloro-2,4-dinitrobenzene, as well as metabolizing diazinon, one of the organophosphate insecticides. Quantitative reverse transcription–polymerase chain reaction analysis of transcripts demonstrated that bmGSTu2 expression was induced 1.7-fold in a resistant strain of B. mori. Mutagenesis of putative amino acid residues in the glutathione-binding site revealed that Ile54, Glu66, Ser67, and Asn68 are crucial for enzymatic function. These results provide insights into the catalysis of glutathione conjugation in silkworm by bmGSTu2 and into the detoxification of organophosphate insecticides. PMID:27440377

  19. Identification of a diazinon-metabolizing glutathione S-transferase in the silkworm, Bombyx mori.

    PubMed

    Yamamoto, Kohji; Yamada, Naotaka

    2016-01-01

    The glutathione S-transferase superfamily play key roles in the metabolism of numerous xenobiotics. We report herein the identification and characterization of a novel glutathione S-transferase in the silkworm, Bombyx mori. The enzyme (bmGSTu2) conjugates glutathione to 1-chloro-2,4-dinitrobenzene, as well as metabolizing diazinon, one of the organophosphate insecticides. Quantitative reverse transcription-polymerase chain reaction analysis of transcripts demonstrated that bmGSTu2 expression was induced 1.7-fold in a resistant strain of B. mori. Mutagenesis of putative amino acid residues in the glutathione-binding site revealed that Ile54, Glu66, Ser67, and Asn68 are crucial for enzymatic function. These results provide insights into the catalysis of glutathione conjugation in silkworm by bmGSTu2 and into the detoxification of organophosphate insecticides. PMID:27440377

  20. Effect of grapeseed oil on diazinon-induced physiological and histopathological alterations in rats

    PubMed Central

    Al-Attar, Atef Mohammed

    2014-01-01

    The pollution of environment by toxic chemicals is a global and chronic problem. Human health risk due to exposure to chemical pollutants is constantly increasing. Pesticides form major toxic chemicals in environment. Scientifically, there is an obviously correlation between the exposure to pesticides and appearance of many diseases. Currently, the significance of natural products for health and medicine has been formidable. The present study investigated the effect of grapeseed oil in male rats exposed to diazinon. The experimental rats were divided into five groups. The rats of the first group were served as control. The experimental animals of the second group were exposed to diazinon (DZN). The animals of the third group were supplemented with grapeseed oil and treated with DZN. The rats of the fourth group were supplemented with grapeseed oil. The experimental rats of the fifth group were supplemented with corn oil. Hematobiochemical and histopathological evaluations were chosen as indicators of DZN toxicity and protective role of grapeseed oil. In rats exposed only to DZN, the levels of serum glucose, triglycerides, cholesterol, low density lipoprotein cholesterol, very low density lipoprotein cholesterol, creatinine, urea nitrogen, uric acid, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, creatine kinase and lactate dehydrogenase were statistically increased, while the level of serum total protein was significantly decreased. Moreover, the histopathological evaluations of the liver, kidney and testis showed that DZN causes several severe alterations. Pretreatment with grapeseed oil exhibited a protective role against DZN toxicity which confirmed by the inhibition of hematobiochemical and histopathological changes due to DZN exposure. Additionally, the present study suggests that the effect of grapeseed oil supplementation against DZN toxicity may be attributed to the antioxidant role of its constituents. PMID:25972749

  1. Environmental Behavior of Chlorpyrifos and Endosulfan in a Tropical Soil in Central Brazil.

    PubMed

    Dores, Eliana F G C; Spadotto, Claudio A; Weber, Oscarlina L S; Dalla Villa, Ricardo; Vecchiato, Antonio B; Pinto, Alicio A

    2016-05-25

    The environmental behavior of chlorpyrifos and endosulfan in soil was studied in the central-western region of Brazil by means of a field experiment. Sorption was evaluated in laboratory batch experiments. Chlorpyrifos and endosulfan were applied to experimental plots on uncultivated soil and the following processes were studied: leaching, runoff, and dissipation in top soil. Field dissipation of chlorpyrifos and endosulfan was more rapid than reported in temperate climates. Despite the high Koc of the studied pesticides, the two endosulfan isomers and endosulfan sulfate as well as chlorpyrifos were detected in percolated water. In runoff water and sediment, both endosulfan isomers and endosulfan sulfate were detected throughout the period of study. Observed losses of endosulfan by leaching (below a depth of 50 cm) and runoff were 0.0013 and 1.04% of the applied amount, whereas chlorpyrifos losses were 0.003 and 0.032%, respectively. Leaching of these highly adsorbed pesticides was attributed to preferential flow. PMID:26635198

  2. Chlorpyrifos exposure in farmers and urban adults: Metabolic characteristic, exposure estimation, and potential effect of oxidative damage.

    PubMed

    Wang, Lei; Liu, Zhen; Zhang, Junjie; Wu, Yinghong; Sun, Hongwen

    2016-08-01

    Chlorpyrifos is a widely used organophosphorus pesticide that efficiently protects crops against pests. However, recent studies suggest that severe exposure to chlorpyrifos may present adverse health effects in human. To analyze the exposure level and metabolic characteristics of chlorpyrifos pesticide in urban adults and farmers with/without occupation pesticide contact, the occurrence of urinary chlorpyrifos and methyl chlorpyrifos (CP-me), as well as their metabolite, 3,5,6-trichloro-2-pyridinol (TCPy), was determined in farmers of an agricultural village in China, and in urban adults of a nearby town. The geometric mean (GM) concentrations of TCPy, which is the major marker of chlorpyrifos exposure, were 4.29 and 7.57μg/g-creatinine in urban adults and farmers before pesticide application, respectively. Chlorpyrifos spraying significantly increased the concentrations of urinary TCPy. In the first day after spraying, a GM concentration of 43.7μg/g-creatinine was detected in the urine specimens from farmers, which decreased to 38.1 and 22.8μg/g-creatinine in the second and third day after chlorpyrifos spraying. The ratio of TCPy and its parent compounds, i.e. chlorpyrifos and CP-me, was positively associated with the sum concentration of urinary chlorpyrifos, CP-me, and TCPy, suggesting the increasing metabolic efficiency of chlorpyrifos to TCPy at higher chlorpyrifos exposure levels. To estimate the farmers' occupational exposure to chlorpyrifos pesticide, a new model based on the fitted first-order elimination kinetics of TCPy was established. Occupational chlorpyrifos exposure in a farmer was estimated to be 3.70μg/kg-bw/day (GM), which is an exposure level that is higher than the recommended guideline levels. Significant increase of urinary 8-hydroxydeoxyguanosine (8-OHdG) was observed on the first day after chlorpyrifos spraying, which indicates a potential oxidative damage in farmers. However, urinary 8-OHdG returned to its baseline level within two

  3. Possible role of vasopressin in the thermoregulatory response to chlorpyrifos in the rat.

    PubMed

    Yang, Yong-La; Gordon, Christopher J

    2002-06-01

    Arginine vasopressin is a naturally occurring antipyretic which is released into the CNS to prevent excessive elevations in body temperature during fever. Circulating levels of arginine vasopressin may also have a role in the tonic control of body temperature. We have found that the organophosphate insecticide chlorpyrifos will raise blood pressure and lower body temperature in the rat. Because arginine vasopressin is a potent hypertensive agent and is capable of lowering core temperature, we suspected that arginine vasopressin may be involved in the thermoregulatory response to chlorpyrifos. To this end, core temperature and motor activity of male and female Sprague-Dawely rats were monitored before and after treatment with the corn oil vehicle or chlorpyrifos (15 mg/kg in females; 30 mg/kg in males; oral) concomitant with injection of a saline vehicle or a type 1 arginine vasopressin antagonist (20 microg/kg in females; 30 microg/kg in males; intraperitoneally). Rats dosed with chlorpyrifos and saline underwent a 2-3 degrees reduction in core temperature >50% decrease in motor activity. The V1 antagonist attenuated the hypothermic effect of chlorpyrifos in both sexes. Chlorpyrifos-induced inhibition in motor activity was unaffected by the V1 antagonist. In another experiment, the V1 antagonist (30 microg/kg) was co-administered with saline or 0.2 mg/kg oxotremorine, a muscarinic agonist that stimulates a heat loss response and partially mimics the effects of chlorpyrifos. The V1 antagonist attenuated the hypothermic effect of oxotremorine in both sexes. Plasma arginine vasopressin levels were determined in male rats 3 hr after corn oil or 30 mg/kg chlorpyrifos. There was no significant effect of chlorpyrifos on plasma levels of arginine vasopressin. That the V1 antagonist blocked the hypothermic effect of chlorpyrifos suggests that the thermoregulatory response to chlorpyrifos is mediated by central and/or systemic vasopressin release. The lack of a significant

  4. A long-term study of the effects of diazinon on sleep, the electrocorticogram and cognitive behaviour in common marmosets.

    PubMed

    Muggleton, N G; Smith, A J; Scott, E A M; Wilson, S J; Pearce, P C

    2005-09-01

    The long-term sequelae of exposure to low doses of organophosphate compounds are ill defined, with effects variously reported on a range of indices of central nervous system functions such as sleep, cognitive performance and electroencephalogram (EEG). These indices were examined in common marmosets exposed to a range of doses of the organophosphorous sheep dip, diazinon. Cognitive performance was assessed by means of elements from the Cambridge Neuropsychological Test Automated Battery (CANTAB), and radiotelemetry techniques were employed to monitor the electrocorticogram and sleep patterns. Data were collected for 12 months following intramuscular administration of a single dose of diazinon (10, 90 or 130 mg.kg (-1)) or vehicle. Although high levels of erythrocyte acetylcholinesterase (AChE) inhibition (up to 82%) and short-term changes in sleep patterns were seen, there was no evidence of biologically significant long-term changes in any measures. The effects of multiple exposures, impurities or mixtures of OP compounds remain to be investigated.

  5. Degradation of chlorpyrifos residues in apple under temperate conditions of Kashmir Valley.

    PubMed

    Mukhtar, Malik; Sherwani, Asma; Wani, Ashraf Alam; Ahmed, Sheikh Bilal; Sofi, Javid Ahmad; Bano, Parveena

    2015-08-01

    The present studies were carried out to observe the dissipation pattern of chlorpyrifos on apple in Kashmir Valley. Persistence of chlorpyrifos in apple was studied following two applications rates of chlorpyrifos (Dursban 20 EC) at 200 g a.i. ha(-1) (single dose T 1) and 400 g a.i. ha(-1) (double dose T 2). The average initial deposit of chlorpyrifos was found to be 1.61 and 1.98 μg g(-1) for T 1 and T 2 application rates respectively on apple. The residues dissipated to 0.09 and 0.06 μg g(-1) after 15- and 30-day post treatment with half-life periods of 3.34 and 5.47 days in T 1 and T 2 application rates, respectively. The residues of chlorpyrifos dissipated to below limit of quantification (LOQ) of 0.04 μg g(-1) after 30 day at T 1 application rate. A waiting period of 6 days must be observed for chlorpyrifos on apple at recommended application rate for the safety of consumers. Theoretical maximum residue contribution (TMRC) values were found to be far less than maximum permissible intake (MPI) at 0 day in both the dosages suggesting chlorpyrifos on apple in Kashmir is unlikely to cause health risks.

  6. Cu(2+) and Fe(2+) mediated photodegradation studies of soil-incorporated chlorpyrifos.

    PubMed

    Rafique, Nazia; Tariq, Saadia R; Ahad, Karam; Taj, Touqeer

    2016-03-01

    The influences of Cu(2+) and Fe(2+) on the photodegradation of soil-incorporated chlorpyrifos were investigated in the present study. The soil samples spiked with chlorpyrifos and selected metal ions were irradiated with UV light for different intervals of time and analyzed by HPLC. The unsterile and sterile control soil samples amended with pesticides and selected metals were incubated in the dark at 25 °C for the same time intervals. The results of the study evidenced that photodegradation of chlorpyrifos followed the first-order kinetics. The dissipation t0.5 of chlorpyrifos was found to decrease from 41 to 20 days under UV irradiation. The rate of chlorpyrifos photodegradation was increased in the presence of both metals, i.e., Cu(2+) and Fe(2+). Thus, initially observed t0.5 of 19.8 days was decreased to 4.39 days in the case of Cu(+2) and 19.25 days for Fe(+2). Copper was found to increase the rate of photodegradation by 4.5 orders of magnitude while the microbial degradation of chlorpyrifos was increased only twofold. The microbial degradation of chlorpyrifos was only negligibly affected by Fe(2+) amendment. The studied trace metals also affected the abiotic degradation of the pesticide in the order Cu(2+) > Fe(2+).

  7. Concentration of hepatic vitamins A and E in rats exposed to chlorpyrifos and/or enrofloxacin.

    PubMed

    Spodniewska, A; Barski, D

    2016-01-01

    The aim of the study was to determine the level of antioxidant vitamins A and E in the liver of rats exposed to chlorpyrifos and/or enrofloxacin. Chlorpyrifos (Group I) was administered at a dose of 0.04 LD50 (6 mg/kg b.w.) for 28 days, and enrofloxacin (Group II) at a dose of 5 mg/kg b.w. for 5 consecutive days. The animals of group III were given both of the mentioned above compounds at the same manner as groups I and II, but enrofloxacin was applied to rats for the last 5 days of chlorpyrifos exposure (i.e. on day 24, 25, 26, 27 and 28). Chlorpyrifos and enrofloxacin were administered to rats intragastrically via a gastric tube. The quantitative determination of vitamins was made by the HPLC method. The results of this study indicated a reduction in the hepatic concentrations of vitamins A and E, compared to the control, which sustained for the entire period of the experiment. The four-week administration of chlorpyrifos to rats resulted in a significant decrease of vitamins in the initial period of the experiment, i.e. up to 24 hours after exposure. For vitamin A the maximum drop was observed after 24 hours (19.24%) and for vitamin E after 6 hours (23.19%). Enrofloxacin caused a slight (3-9%) reduction in the level of the analysed vitamins. In the chlorpyrifos-enrofloxacin co-exposure group reduced vitamins A and E levels were also noted, but changes in this group were less pronounced in comparison to the animals intoxicated with chlorpyrifos only. The decrease in the antioxidant vitamin levels, particularly noticeable in the chlorpyrifos- and the chlorpyrifos combined with enrofloxacin-treated groups, may result not only from the increase in the concentration of free radicals, but also from the intensification of the secondary stages of lipid peroxidation. PMID:27487512

  8. Genetics and preliminary mechanism of chlorpyrifos resistance in Phenacoccus solenopsis Tinsley (Homoptera: Pseudococcidae).

    PubMed

    Afzal, Muhammad Babar Shahzad; Ijaz, Mamuna; Farooq, Zahra; Shad, Sarfraz Ali; Abbas, Naeem

    2015-03-01

    Cotton mealybug, Phenacoccus solenopsis Tinsley, is a serious pest of cotton and other crops and infestation by this pest results in yield losses that affect the economy of Pakistan. Various groups of insecticides have been used to control this pest but resistance development is a major factor that inhibits its control in the field. Chlorpyrifos is a common insecticide used against many pests including P. solenopsis. The present experiment was designed to assess the genetics and mechanism of chlorpyrifos resistance and to develop a better resistance management strategy and assess the genetics and mechanism of chlorpyrifos resistance. Before selection, the field strain showed 3.1-fold resistance compared to the susceptible strain (CSS). After 8 rounds of selection with chlorpyrifos, a selected population developed a 191.0-fold resistance compared to the CSS. The LC50 values of F1 (CRR ♀ × CSS ♂) and F1(†) (CRR ♂ × CSS ♀) strains were not significantly different and dominance (DLC) values were 0.42 and 0.55. Reciprocal crosses between chlorpyrifos susceptible and resistant strains indicated that resistance was autosomal and incompletely recessive. The monogenic model of fit test and calculation of number of genes segregating in the chlorpyrifos resistant strain demonstrated that resistance is controlled by multiple genes. A value of 0.59 was calculated for realized heritability for chlorpyrifos resistance. Synergism bioassays with piperonyl butoxide and S, S, S-butyl phosphorotrithioate showed that chlorpyrifos resistance was associated with microsomal oxidases and esterases. It was concluded that chlorpyrifos resistance in P. solenopsis was autosomally inherited, incompletely recessive and polygenic. These findings would be helpful to improve the management of P. solenopsis.

  9. The effects of chlorpyrifos on blood pressure and temperature regulation in spontaneously hypertensive rats.

    PubMed

    Smith, Edward G; Gordon, Christopher J

    2005-06-01

    Using radiotelemetry to monitor blood pressure and core temperature, studies in our laboratory have shown that a prolonged hypertensive response is elicited in rats exposed to chlorpyrifos, an organophosphate-based insecticide. Chlorpyrifos inhibits acetylcholinesterase activity, resulting in central and peripheral stimulation of central cholinergic pathways involved in blood pressure regulation. The spontaneously hypertensive rat has been shown to be more sensitive to central cholinergic stimulation. Therefore, we hypothesized that these rats would be more susceptible and sustain a greater hypertensive response when exposed to chlorpyrifos. Heart rate, cardiac contractility, core temperature, and blood pressure were monitored by radiotelemetry in SHRs and their Wistar Kyoto (WKY) normotensive controls following exposure to chlorpyrifos (10 mg/kg or 25 mg/kg, orally). Baseline blood pressure of SHRs was approximately 35 mmHg above that of WKYs prior to dosing. SHRs exhibited a greater and more sustained elevation in diastolic, mean and systolic blood pressure following exposure to 25 mg/kg of chlorpyrifos. The rise in blood pressure lasted for approximately 56 hours in SHRs compared to approximately 32 hours in WKYs. Chlorpyrifos also led to a prolonged elevation in daytime heart rate in both strains. There was a transient elevation in cardiac contractility in both strains lasting approximately 7 hr after exposure to chlorpyrifos. The hypothermic response to chlorpyrifos was similar in magnitude and duration for both strains. Plasma cholinesterase activity measured 4 hr after exposure to 25 mg/kg chlorpyrifos was inhibited to approximately 40% of control levels in both strains. Using the SHR strain as a model to study susceptible populations, the data suggest that individuals with a genetic predisposition to hypertension may be more susceptible from exposure to organophosphate-based insecticide, as manifested by an exacerbated hypertensive response. PMID:15910416

  10. Non-accidental chlorpyrifos poisoning-an unusual cause of profound unconsciousness.

    PubMed

    Lee, Jiun-Chang; Lin, Kuang-Lin; Lin, Jainn-Jim; Hsia, Shao-Hsuan; Wu, Chang-Teng

    2010-04-01

    Chlorpyrifos is an organophosphorus anticholinesterase insecticide, and organophosphate intoxication can induce symptoms such as miosis, urination, diarrhea, diaphoresis, lacrimation, excitation of central nervous system, salivation, and consciousness disturbance (MUDDLES). Although accidental poisoning of children with drugs and chemicals is a common cause for consciousness disturbance in children, the possibility of deliberate poisoning is rarely considered. We report on a healthy 5-year 6-month-old boy with recurrent organophosphate intoxication. Reports of chlorpyrifos intoxication in children are quite rare. This case report demonstrates decision-making process and how to disclose deliberate chlorpyrifos poisoning of the toddler by the stepmother, another example of Munchausen syndrome by proxy.

  11. THE MUSCARINIC ANTAGONIST SCOPOLAMINE ATTENUATES CHLORPYRIFOS INDUCED HYPOTHERMIA IN THE DEVELOPING RAT.

    EPA Science Inventory

    Chlorpyrifos (CHP), an anticholinesterase organophosphate (OP) pesticide, induces acute hypothermia in adult and developing rats. Previously we demonstrated that thermoregulation in preweanling pups is markedly more sensitive to the neurotoxic effects of CHP than in adults. The c...

  12. INCREASED SUSCEPTIBILITY OF THE SPONTANEOUSLY HYPERTENSIVE RAT TO CHLORPYRIFOS, AN ORGANOPHOSPHATE PESTICIDE.

    EPA Science Inventory

    Hypertension and hypothermia are common symptoms in rats exposed to chlorpyrifos (CHP), an organophosphate (OP)-based pesticide. CHP inhibits acetylcholinesterase (AChE) activity resulting in central and peripheral stimulation of cholinergic pathways involved in blood pressure ...

  13. MODELED ESTIMATES OF CHLORPYRIFOS EXPOSURE AND DOSE FOR THE MINNESOTA AND ARIZONA NHEXAS POPULATIONS

    EPA Science Inventory

    This paper presents a probabilistic, multimedia, multipathway exposure model and assessment for chlorpyrifos developed as part of the National Human Exposure Assessment Survey (NHEXAS). The model was constructed using available information prior to completion of the NHEXAS stu...

  14. THE EFFECTS OF CHRONIC EXERCISE CONDITIONING ON THERMOREGULATORY RESPONSE TO CHLORPYRIFOS IN FEMALE RATS.

    EPA Science Inventory

    Chronic exercise conditioning has been shown to alter basal thermoregulatory processes (change in thermoregulatory set-point) as well as the response to infectious fever. Chlorpyrifos (CHP), an organophosphate pesticide, causes an acute period of hypothermia followed by a delaye...

  15. Occurrence and Transport of Diazinon in the Sacramento River and Selected Tributaries, California, during Two Winter Storms, January?February 2001

    USGS Publications Warehouse

    Dileanis, Peter D.; Brown, David L.; Knifong, Donna L.; Saleh, Dina

    2003-01-01

    Diazinon, an organophosphate insecticide, is applied as an orchard dormant spray in the Sacramento Valley during the winter months when the area receives most of its annual rainfall. During winter rainstorms that frequently follow dormant spray applications, some of the applied pesticide is transported in storm runoff to the Sacramento River and its tributaries. Diazinon is also used to control insect pests on residential and commercial properties in urban areas and is frequently detected in urban storm runoff draining into the Sacramento River system. Between January 24 and February 14, 2001, diazinon concentrations and loads were measured in the Sacramento River and selected tributaries during two winter storms that occurred after dormant spray applications were made to orchards in the Sacramento Valley. Water samples were collected at 21 sites that represented agricultural and urban inputs on a variety of scales, from small tributaries and drains representing local land use to main-stem river sites representing regional effects. Concentrations of diazinon ranged from below laboratory reporting levels to 1,380 nanograms per liter (ng/L), with a median of 55 ng/L during the first monitored storm and 26 ng/L during the second. The highest concentrations were observed in small channels draining predominantly agricultural land. About 26,000 pounds of diazinon were reported applied to agricultural land in the study area just before and during the monitoring period. About 0.2 percent of the applied insecticide appeared to be transported to the lower Sacramento River during that period. The source of about one third of the total load measured in the lower Sacramento River appears to be in the portion of the drainage basin upstream of the city of Colusa. About 12 percent of the diazinon load in the lower Sacramento River was transported from the Feather River Basin, which drains much of the mountainous eastern portions of the Sacramento River Basin. Diazinon use in the

  16. Adsorption of diazinon and hinosan molecules on the iron-doped boron nitride nanotubes surface in gas phase and aqueous solution: A computational study

    NASA Astrophysics Data System (ADS)

    Farmanzadeh, Davood; Rezainejad, Hamid

    2016-02-01

    In this study, the geometric structures and electronic properties of two widely used organophosphorus pesticides, diazinon and hinosan, boron nitride nanotubes (BNNTs) and Fe doped boron nitride nanotubes (FeBNNTs) as adsorbents of these pesticides are studied by density functional theory calculation as well as dispersion correction by Grimme method. The results show that Fe doping in boron nitride nanotubes structures increases the potency of nanotubes to adsorb mentioned pesticides, especially when Fe atom located instead of N atom. Comparing the adsorption energies of diazinon on FeBNNTs with ones for hinosan demonstrate that the adsorption of hinosan is energetically more favorable by FeBNNTs. Assessment of adsorption energies in aqueous solution confirmed significant decrease in their values compared to ones in gaseous phase. However, the adsorption of diazinon and hinosan on both BNNTs and FeBNNTs are exothermic. So, BNNTs and FeBNNTs may be promising candidates as appropriate adsorbents for adsorbing diazinon and hinosan. Also, the results of calculations have revealed that van der Waals interaction energies are remarkably large in adsorption of diazinon and hinosan on all boron nitride nanotubes.

  17. Toxicological effects of chlorpyrifos on growth, enzyme activity and chlorophyll a synthesis of freshwater microalgae.

    PubMed

    Chen, Shangchao; Chen, Mindong; Wang, Zhuang; Qiu, Weijian; Wang, Junfeng; Shen, Yafei; Wang, Yajun; Ge, Shun

    2016-07-01

    This paper aims to acquire the experimental data on the eco-toxicological effects of agricultural pollutants on the aquatic plants and the data can support the assessment of toxicity on the phytoplankton. The pesticide of Chlorpyrifos used as a good model to investigate its eco-toxicological effect on the different microalgae in freshwater. In order to address the pollutants derived from forestry and agricultural applications, freshwater microalgae were considered as a good sample to investigate the impact of pesticides such as Chlorpyrifos on aquatic life species. Two microalgae of Chlorella pyrenoidosa and Merismopedia sp. were employed to evaluate toxicity of Chlorpyrifos in short time and long time by means of measuring the growth inhibition rate, the redox system and the content of chlorophyll a, respectively. In this study, the results showed that EC50 values ranging from 7.63 to 19.64mg/L, indicating the Chlorpyrifos had a relatively limited to the growth of algae during the period of the acute toxicity experiment. Moreover, when two kinds of algae were exposed to a medium level of Chlorpyrifos, SOD and CAT activities were importantly advanced. Therefore, the growth rate and SOD and CAT activities can be highly recommended for the eco-toxicological assessment. In addition, chlorophyll a also could be used as a targeted parameter for assessing the eco-toxicity of Chlorpyrifos on both Chlorella pyrenoidosa and Merismopedia sp. PMID:27314761

  18. Sediment microbes and biofilms increase the bioavailability of chlorpyrifos in Chironomus riparius (Chironomidae, Diptera).

    PubMed

    Widenfalk, Anneli; Lundqvist, Anna; Goedkoop, Willem

    2008-10-01

    In a microcosm study, the importance of different sources of organic matter (humic acids, sterile sediment, sediment, and a microbial extract) for the bioavailability of the hydrophobic pesticide chlorpyrifos to Chironomus riparius larvae was quantified. In the last two treatments biofilms were allowed to grow before (14)C-chlorpyrifos addition. Chlorpyrifos accumulation was quantified after 25 h of exposure and after 21 h of depuration. Larval accumulation was twice as high in the microbial extract treatment (447+/-79 microg/kg ww larvae) and 1.7 times higher in the sediment treatment (371+/-33 microg/kg). After depuration, chlorpyrifos accumulation in larval tissue showed even higher differences; 3.1 times higher tissue concentrations in the microbial extract treatment (218+/-21 microg/kg) and 2.2 times higher in the sediment treatment (156+/-35 microg/kg). In contrast, chlorpyrifos accumulation in the humic acid and sterile sediment did not differ from that in controls. These results show that living microbes and biofilms, by creating a microenvironment and providing food for larvae, markedly increase the bioavailability of chlorpyrifos to Chironomus riparius.

  19. Biotransformation of chlorpyrifos in riparian wetlands in agricultural watersheds: implications for wetland management.

    PubMed

    Karpuzcu, M Ekrem; Sedlak, David L; Stringfellow, William T

    2013-01-15

    Biodegradation of the organophosphate insecticide chlorpyrifos (O,O-diethyl O-(3,5,6-trichloropyridin-2-yl) phosphorothioate) in sediments from wetlands and agricultural drains in San Joaquin Valley, CA was investigated. Sediments were collected monthly, spiked with chlorpyrifos, and rates of chlorpyrifos degradation were measured using a standardized aerobic biodegradation assay. Phosphoesterase enzyme activities were measured and phosphotriesterase activity was related to observed biodegradation kinetics. First-order biodegradation rates varied between 0.02 and 0.69 day(-1), after accounting for abiotic losses. The average rate of abiotic chlorpyrifos hydrolysis was 0.02 d(-1) at pH 7.2 and 30 °C. Sediments from the site exhibiting the highest chlorpyrifos degradation capacity were incubated under anaerobic conditions to assess the effect of redox conditions on degradation rates. Half-lives were 5 and 92 days under aerobic and anaerobic conditions, respectively. There was a consistent decrease in observed biodegradation rates at one site due to permanently flooded conditions prevailing during one sampling year. These results suggest that wetland management strategies such as allowing a wet-dry cycle could enhance degradation rates. There was significant correlation between phosphotriesterase (PTE) activity and the chlorpyrifos biotransformation rates, with this relationship varying among sites. PTE activities may be useful as an indicator of biodegradation potential with reference to the previously established site-specific correlations.

  20. Development of a Freeze-Dried Fungal Wettable Powder Preparation Able to Biodegrade Chlorpyrifos on Vegetables

    PubMed Central

    Chen, Shaohua; Xiao, Ying; Hu, Meiying; Zhong, Guohua

    2014-01-01

    Continuous use of the pesticide chlorpyrifos has resulted in harmful contaminations in environment and species. Based on a chlorpyrifos-degrading fungus Cladosporium cladosporioides strain Hu-01 (collection number: CCTCC M 20711), a fungal wettable powder preparation was developed aiming to efficiently remove chlorpyrifos residues from vegetables. The formula was determined to be 11.0% of carboxymethyl cellulose-Na, 9.0% of polyethylene glycol 6000, 5.0% of primary alcohol ethoxylate, 2.5% of glycine, 5.0% of fucose, 27.5% of kaolin and 40% of freeze dried fungi by response surface methodology (RSM). The results of quality inspection indicated that the fungal preparation could reach manufacturing standards. Finally, the degradation of chlorpyrifos by this fungal preparation was determined on pre-harvest cabbage. Compared to the controls without fungal preparation, the degradation of chlorpyrifos on cabbages, which was sprayed with the fungal preparation, was up to 91% after 7 d. These results suggested this freeze-dried fungal wettable powder may possess potential for biodegradation of chlorpyrifos residues on vegetables and provide a potential strategy for food and environment safety against pesticide residues. PMID:25061758

  1. Development of a freeze-dried fungal wettable powder preparation able to biodegrade chlorpyrifos on vegetables.

    PubMed

    Liu, Jie; He, Yue; Chen, Shaohua; Xiao, Ying; Hu, Meiying; Zhong, Guohua

    2014-01-01

    Continuous use of the pesticide chlorpyrifos has resulted in harmful contaminations in environment and species. Based on a chlorpyrifos-degrading fungus Cladosporium cladosporioides strain Hu-01 (collection number: CCTCC M 20711), a fungal wettable powder preparation was developed aiming to efficiently remove chlorpyrifos residues from vegetables. The formula was determined to be 11.0% of carboxymethyl cellulose-Na, 9.0% of polyethylene glycol 6000, 5.0% of primary alcohol ethoxylate, 2.5% of glycine, 5.0% of fucose, 27.5% of kaolin and 40% of freeze dried fungi by response surface methodology (RSM). The results of quality inspection indicated that the fungal preparation could reach manufacturing standards. Finally, the degradation of chlorpyrifos by this fungal preparation was determined on pre-harvest cabbage. Compared to the controls without fungal preparation, the degradation of chlorpyrifos on cabbages, which was sprayed with the fungal preparation, was up to 91% after 7 d. These results suggested this freeze-dried fungal wettable powder may possess potential for biodegradation of chlorpyrifos residues on vegetables and provide a potential strategy for food and environment safety against pesticide residues.

  2. Feasibility of using drinking water treatment residuals as a novel chlorpyrifos adsorbent.

    PubMed

    Zhao, Yuanyuan; Wang, Changhui; Wendling, Laura A; Pei, Yuansheng

    2013-08-01

    Recent efforts have increasingly focused on the development of low-cost adsorbents for pesticide retention. In this work, the novel reuse of drinking water treatment residuals (WTRs), a nonhazardous ubiquitous byproduct, as an adsorbent for chlorpyrifos was investigated. Results showed that the kinetics and isothermal processes of chlorpyrifos sorption to WTRs were better described by a pseudo-second-order model and by the Freundlich equation, respectively. Moreover, compared with paddy soil and other documented absorbents, the WTRs exhibited a greater affinity for chlorpyrifos (log Koc = 4.76-4.90) and a higher chlorpyrifos sorption capacity (KF = 5967 mg(1-n)·L·kg(-1)) owing to the character and high content of organic matter. Further investigation demonstrated that the pH had a slight but statistically insignificant effect on chlorpyrifos sorption to WTRs; solution ionic strength and the presence of low molecular weight organic acids both resulted in concentration-dependent inhibition effects. Overall, these results confirmed the feasibility of using WTRs as a novel chlorpyrifos adsorbent.

  3. Removal of chlorpyrifos by water lettuce (Pistia stratiotes L.) and duckweed (Lemna minor L.).

    PubMed

    Prasertsup, Pichamon; Ariyakanon, Naiyanan

    2011-04-01

    The potential of water lettuce (Pistia stratiotes L.) and duckweed (Lemna minor L.) to remove chlorpyrifos in water was investigated under laboratory greenhouse conditions. At initial chlorpyrifos concentrations of 0.0, 0.1 and 0.5 mg/L, the relative growth rates (RGR) of L. minor and P. stratiotes were not significantly different. In contrast, in the presence of 1 mg/L chlorpyrifos the RGR was significantly inhibited, giving an observed fresh weight based RGR(FW) for P. stratiotes and L. minor from day 0 to 7 of -0.036 and -0.023 mg/g/day, respectively. The maximum removal of chlorpyrifos by P. stratiotes and L. minor, when chlorpyrifos was at an initial culture concentration of 0.5 mg/L, was 82% and 87%, respectively, with disappearance rate constants under these conditions of 2.94, 10.21 and 12.14 microg h(-1) for the control (no plants), and with P. stratiotes and L. minor, respectively, giving actual corrected plant removal rate constants of 7.27 and 9.20 microg h(-1) for P. stratiotes and L. minor, respectively. The bioconcentration factor (BCF) of L. minor was significantly greater than that for P. stratiotes and therefore, at least under these greenhouse-based conditions, L. minor was more efficient than P. stratiotes for the accelerated removal of chlorpyrifos from water.

  4. Diazinon and diazoxon impair the ability of astrocytes to foster neurite outgrowth in primary hippocampal neurons

    SciTech Connect

    Pizzurro, Daniella M.; Dao, Khoi; Costa, Lucio G.

    2014-02-01

    Evidence from in vivo and epidemiological studies suggests that organophosphorus insecticides (OPs) are developmental neurotoxicants, but possible underlying mechanisms are still unclear. Astrocytes are increasingly recognized for their active role in normal neuronal development. This study sought to investigate whether the widely-used OP diazinon (DZ), and its oxygen metabolite diazoxon (DZO), would affect glial–neuronal interactions as a potential mechanism of developmental neurotoxicity. Specifically, we investigated the effects of DZ and DZO on the ability of astrocytes to foster neurite outgrowth in primary hippocampal neurons. The results show that both DZ and DZO adversely affect astrocyte function, resulting in inhibited neurite outgrowth in hippocampal neurons. This effect appears to be mediated by oxidative stress, as indicated by OP-induced increased reactive oxygen species production in astrocytes and prevention of neurite outgrowth inhibition by antioxidants. The concentrations of OPs were devoid of cytotoxicity, and cause limited acetylcholinesterase inhibition in astrocytes (18 and 25% for DZ and DZO, respectively). Among astrocytic neuritogenic factors, the most important one is the extracellular matrix protein fibronectin. DZ and DZO decreased levels of fibronectin in astrocytes, and this effect was also attenuated by antioxidants. Underscoring the importance of fibronectin in this context, adding exogenous fibronectin to the co-culture system successfully prevented inhibition of neurite outgrowth caused by DZ and DZO. These results indicate that DZ and DZO increase oxidative stress in astrocytes, and this in turn modulates astrocytic fibronectin, leading to impaired neurite outgrowth in hippocampal neurons. - Highlights: • DZ and DZO inhibit astrocyte-mediated neurite outgrowth in rat hippocampal neurons. • Oxidative stress is involved in inhibition of neuritogenesis by DZ and DZO. • DZ and DZO decrease expression of the neuritogenic

  5. Diazinon alters sperm chromatin structure in mice by phosphorylating nuclear protamines

    SciTech Connect

    Pina-Guzman, B.; Solis-Heredia, M.J.; Quintanilla-Vega, B. . E-mail: mquintan@mail.cinvestav.mx

    2005-01-15

    Organophosphorus (OP) pesticides, widely used in agriculture and pest control, are associated with male reproductive effects, including sperm chromatin alterations, but the mechanisms underlying these effects are unknown. The main toxic action of OP is related to phosphorylation of proteins. Chemical alterations in sperm nuclear proteins (protamines), which pack DNA during the last steps of spermatogenesis, contribute to male reproductive toxicity. Therefore, in the present study, we tested the ability of diazinon (DZN), an OP compound, to alter sperm chromatin by phosphorylating nuclear protamines. Mice were injected with a single dose of DZN (8.12 mg/kg, i.p.), and killed 8 and 15 days after treatment. Quality of sperm from epididymis and vas deferens was evaluated through standard methods and chromatin condensation by flow cytometry (DNA Fragmented Index parameters: DFI and DFI%) and fluorescence microscopy using chromomycin-A{sub 3} (CMA{sub 3}). Increases in DFI (15%), DFI% (4.5-fold), and CMA{sub 3} (2-fold) were observed only at 8 days post-treatment, indicating an alteration in sperm chromatin condensation and DNA damage during late spermatid differentiation. In addition, an increase of phosphorous content (approximately 50%) in protamines, especially in the phosphoserine content (approximately 73%), was found at 8 days post-treatment. Sperm viability, motility, and morphology showed significant alterations at this time. These data strongly suggest that spermatozoa exposed during the late steps of maturation were the targets of DZN exposure. The correlation observed between the phosphorous content in nuclear protamines with DFI%, DFI, and CMA{sub 3} provides evidence that phosphorylation of nuclear protamines is involved in the OP effects on sperm chromatin.

  6. Sensitivity of Ethiopian aquatic macroinvertebrates to the pesticides endosulfan and diazinon, compared to literature data.

    PubMed

    Teklu, Berhan M; Retta, Negussie; Van den Brink, Paul J

    2016-08-01

    The aims of the present study were to present a methodology for toxicity tests that can be used when analytical resources to verify the test concentrations are limited, and to evaluate whether the sensitivity of a limited number of Ethiopian species to pesticides differs from literature values for, mainly, temperate species. Acute toxicity tests were performed using three Ethiopian aquatic invertebrate species, one crustacean (Diaphanosoma brachyurum) and two insects (Anopheles pharoensis and Culex pipiens) and using the pesticides endosulfan and diazinon. All species-pesticide combinations were tested in duplicate to estimate the consistency, i.e. the intra-laboratory variation, in test results. Daphnia magna was tested as well to allow the test results to be compared directly with values from the literature. Results indicate that the differences between the EC50s obtained for D. magna in this study and those reported in the literature were less than a factor of 2. This indicates that the methodology used is able to provide credible toxicity values. The results of the duplicated tests showed intra-laboratory variation in EC50 values of up to a factor of 3, with one test showing a difference of a factor of 6 at 48 h. Comparison with available literature results for arthropod species using species sensitivity distributions indicated that the test results obtained in this study fit well in the log-normal distribution of the literature values. We conclude that the methodology of performing multiple tests to check for consistency of test results and performing tests with D. magna for comparison with literature values to check for accuracy is able to provide reliable effect threshold levels and that the tested Ethiopian species did not differ in sensitivity from the arthropod species reported on in the literature.

  7. Sensitivity of Ethiopian aquatic macroinvertebrates to the pesticides endosulfan and diazinon, compared to literature data.

    PubMed

    Teklu, Berhan M; Retta, Negussie; Van den Brink, Paul J

    2016-08-01

    The aims of the present study were to present a methodology for toxicity tests that can be used when analytical resources to verify the test concentrations are limited, and to evaluate whether the sensitivity of a limited number of Ethiopian species to pesticides differs from literature values for, mainly, temperate species. Acute toxicity tests were performed using three Ethiopian aquatic invertebrate species, one crustacean (Diaphanosoma brachyurum) and two insects (Anopheles pharoensis and Culex pipiens) and using the pesticides endosulfan and diazinon. All species-pesticide combinations were tested in duplicate to estimate the consistency, i.e. the intra-laboratory variation, in test results. Daphnia magna was tested as well to allow the test results to be compared directly with values from the literature. Results indicate that the differences between the EC50s obtained for D. magna in this study and those reported in the literature were less than a factor of 2. This indicates that the methodology used is able to provide credible toxicity values. The results of the duplicated tests showed intra-laboratory variation in EC50 values of up to a factor of 3, with one test showing a difference of a factor of 6 at 48 h. Comparison with available literature results for arthropod species using species sensitivity distributions indicated that the test results obtained in this study fit well in the log-normal distribution of the literature values. We conclude that the methodology of performing multiple tests to check for consistency of test results and performing tests with D. magna for comparison with literature values to check for accuracy is able to provide reliable effect threshold levels and that the tested Ethiopian species did not differ in sensitivity from the arthropod species reported on in the literature. PMID:27221822

  8. Nanoimages show disruption of tubulin polymerization by chlorpyrifos oxon: Implications for neurotoxicity

    SciTech Connect

    Grigoryan, Hasmik; Lockridge, Oksana

    2009-10-15

    Organophosphorus agents cause cognitive deficits and depression in some people. We hypothesize that the mechanism by which organophosphorus agents cause these disorders is by modification of proteins in the brain. One such protein could be tubulin. Tubulin polymerizes to make the microtubules that transport cell components to nerve axons. The goal of the present work was to measure the effect of the organophosphorus agent chlorpyrifos oxon on tubulin polymerization. An additional goal was to identify the amino acids covalently modified by chlorpyrifos oxon in microtubule polymers and to compare them to the amino acids modified in unpolymerized tubulin dimers. Purified bovine tubulin (0.1 mM) was treated with 0.005-0.1 mM chlorpyrifos oxon for 30 min at room temperature and then polymerized by addition of 1 mM GTP to generate microtubules. Microtubules were visualized by atomic force microscopy. Chlorpyrifos oxon-modified residues were identified by tandem ion trap electrospray ionization and matrix-assisted laser desorption/ionization mass spectrometry of tryptic peptides. Nanoimaging showed that low concentrations (0.005 and 0.01 mM) of chlorpyrifos oxon yielded short, thin microtubules. A concentration of 0.025 mM stimulated polymerization, while high concentrations (0.05 and 0.1 mM) caused aggregation. Of the 17 tyrosines covalently modified by chlorpyrifos oxon in unpolymerized tubulin dimers, only 2 tyrosines were labeled in polymerized microtubules. The two labeled tyrosines in polymerized tubulin were Tyr 103 in EDAANNY*R of alpha tubulin, and Tyr 281 in GSQQY*R of beta tubulin. In conclusion, chlorpyrifos oxon binding to tubulin disrupts tubulin polymerization. These results may lead to an understanding of the neurotoxicity of organophosphorus agents.

  9. A Human Life-Stage Physiologically Based Pharmacokinetic and Pharmacodynamic Model for Chlorpyrifos: Development and Validation

    SciTech Connect

    Smith, Jordan N.; Hinderliter, Paul M.; Timchalk, Charles; Bartels, M. J.; Poet, Torka S.

    2014-08-01

    Sensitivity to chemicals in animals and humans are known to vary with age. Age-related changes in sensitivity to chlorpyrifos have been reported in animal models. A life-stage physiologically based pharmacokinetic and pharmacodynamic (PBPK/PD) model was developed to computationally predict disposition of CPF and its metabolites, chlorpyrifos-oxon (the ultimate toxicant) and 3,5,6-trichloro-2-pyridinol (TCPy), as well as B-esterase inhibition by chlorpyrifos-oxon in humans. In this model, age-dependent body weight was calculated from a generalized Gompertz function, and compartments (liver, brain, fat, blood, diaphragm, rapid, and slow) were scaled based on body weight from polynomial functions on a fractional body weight basis. Blood flows among compartments were calculated as a constant flow per compartment volume. The life-stage PBPK/PD model was calibrated and tested against controlled adult human exposure studies. Model simulations suggest age-dependent pharmacokinetics and response may exist. At oral doses ≥ 0.55 mg/kg of chlorpyrifos (significantly higher than environmental exposure levels), 6 mo old children are predicted to have higher levels of chlorpyrifos-oxon in blood and higher levels of red blood cell cholinesterase inhibition compared to adults from equivalent oral doses of chlorpyrifos. At lower doses that are more relevant to environmental exposures, the model predicts that adults will have slightly higher levels of chlorpyrifos-oxon in blood and greater cholinesterase inhibition. This model provides a computational framework for age-comparative simulations that can be utilized to predict CPF disposition and biological response over various postnatal life-stages.

  10. CHLORPYRIFOS AND 3,5,6 TRICHLORO-2-PYRIDINOL DISTRIBUTION IN RAT BLOOD AND BRAIN DURING CHRONIC DIETARY AND REPEATED HIGH LEVEL ACUTE EXPOSURE TO CHLORPYRIFOS.

    EPA Science Inventory

    The aim of this study was to determine the concentrations of an organophosphorus pesticide, chlorpyrifos (CPF), and the metabolite 3,5,6 trichloro-2-pyridinol (TCP) in tissues from rats exposed to long-term, low-dose CPF. Adult, Long-Evans male rats received CPF for one year at ...

  11. Chlorpyrifos exposure in farmers and urban adults: Metabolic characteristic, exposure estimation, and potential effect of oxidative damage.

    PubMed

    Wang, Lei; Liu, Zhen; Zhang, Junjie; Wu, Yinghong; Sun, Hongwen

    2016-08-01

    Chlorpyrifos is a widely used organophosphorus pesticide that efficiently protects crops against pests. However, recent studies suggest that severe exposure to chlorpyrifos may present adverse health effects in human. To analyze the exposure level and metabolic characteristics of chlorpyrifos pesticide in urban adults and farmers with/without occupation pesticide contact, the occurrence of urinary chlorpyrifos and methyl chlorpyrifos (CP-me), as well as their metabolite, 3,5,6-trichloro-2-pyridinol (TCPy), was determined in farmers of an agricultural village in China, and in urban adults of a nearby town. The geometric mean (GM) concentrations of TCPy, which is the major marker of chlorpyrifos exposure, were 4.29 and 7.57μg/g-creatinine in urban adults and farmers before pesticide application, respectively. Chlorpyrifos spraying significantly increased the concentrations of urinary TCPy. In the first day after spraying, a GM concentration of 43.7μg/g-creatinine was detected in the urine specimens from farmers, which decreased to 38.1 and 22.8μg/g-creatinine in the second and third day after chlorpyrifos spraying. The ratio of TCPy and its parent compounds, i.e. chlorpyrifos and CP-me, was positively associated with the sum concentration of urinary chlorpyrifos, CP-me, and TCPy, suggesting the increasing metabolic efficiency of chlorpyrifos to TCPy at higher chlorpyrifos exposure levels. To estimate the farmers' occupational exposure to chlorpyrifos pesticide, a new model based on the fitted first-order elimination kinetics of TCPy was established. Occupational chlorpyrifos exposure in a farmer was estimated to be 3.70μg/kg-bw/day (GM), which is an exposure level that is higher than the recommended guideline levels. Significant increase of urinary 8-hydroxydeoxyguanosine (8-OHdG) was observed on the first day after chlorpyrifos spraying, which indicates a potential oxidative damage in farmers. However, urinary 8-OHdG returned to its baseline level within two

  12. Properties and uses of chlorpyrifos in the United States.

    PubMed

    Solomon, Keith R; Williams, W Martin; Mackay, Donald; Purdy, John; Giddings, Jeffrey M; Giesy, John P

    2014-01-01

    Physical properties and use data provide the basis for estimating environmental exposures to chlorpyrifos (CPY) and for assessing its risks. The vapor pressure ofCPY is low, solubility in water is <1 mg L-1, and its log Kow is 5. Chlorpyrifos has short to moderate persistence in the environment as a result of several dissipation pathways that may proceed concurrently. Primary mechanisms of dissipation include volatilization, photolysis, abiotic hydrolysis, and microbial degradation.Volatilization dominates dissipation from foliage in the initial 12 h after application,but decreases as CPY adsorbs to foliage or soil. In the days after application, CPY adsorbs more strongly to soil, and penetrates more deeply into the soil matrix,becoming less available for volatilization. After the first 12 h, other processes of degradation, such as chemical hydrolysis and catabolism by microbiota become important. The half-life of CPY in soils tested in the laboratory ranged from 2 toI ,575 d (N = 126) and is dependent on properties of the soil and rate of application.At application rates used historically for control of termites, the degradation rate is much slower than for agricultural uses. In agricultural soils under field conditions,half-lives are shorter (2 to 120 d, N=58). The mean water-soil adsorption coefficient(Koc) of CPY is 8,216 mL g-1; negligible amounts enter plants via the roots,and it is not translocated in plants. Half-lives for hydrolysis in water are inversely dependent on pH, and range from 16 to 73 d. CPY is an inhibitor of acetylcholinesterase and is potentially toxic to most animals. Differences in susceptibility result from differences in rates of adsorption,distribution, metabolism, and excretion among species. CPY is an important tool in management of a large number of pests (mainly insects and mites) and is used on a wide range of crops in the U.S. Estimates of annual use in the U.S. from 2008 to 2012 range from 3.2 to 4.1 M kg y-1, which is about 50

  13. Purification and characterization of a novel chlorpyrifos hydrolase from Cladosporium cladosporioides Hu-01.

    PubMed

    Gao, Yan; Chen, Shaohua; Hu, Meiying; Hu, Qiongbo; Luo, Jianjun; Li, Yanan

    2012-01-01

    Chlorpyrifos is of great environmental concern due to its widespread use in the past several decades and its potential toxic effects on human health. Thus, the degradation study of chlorpyrifos has become increasing important in recent years. A fungus capable of using chlorpyrifos as the sole carbon source was isolated from organophosphate-contaminated soil and characterized as Cladosporium cladosporioides Hu-01 (collection number: CCTCC M 20711). A novel chlorpyrifos hydrolase from cell extract was purified 35.6-fold to apparent homogeneity with 38.5% overall recovery by ammoniumsulfate precipitation, gel filtration chromatography and anion-exchange chromatography. It is a monomeric structure with a molecular mass of 38.3 kDa. The pI value was estimated to be 5.2. The optimal pH and temperature of the purified enzyme were 6.5 and 40°C, respectively. No cofactors were required for the chlorpyrifos-hydrolysis activity. The enzyme was strongly inhibited by Hg²⁺, Fe³⁺, DTT, β-mercaptoethanol and SDS, whereas slight inhibitory effects (5-10% inhibition) were observed in the presence of Mn²⁺, Zn²⁺, Cu²⁺, Mg²⁺, and EDTA. The purified enzyme hydrolyzed various organophosphorus insecticides with P-O and P-S bond. Chlorpyrifos was the preferred substrate. The Km and Vmax values of the enzyme for chlorpyrifos were 6.7974 μM and 2.6473 μmol·min⁻¹, respectively. Both NH2-terminal sequencing and matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometer (MALDI-TOF-MS) identified an amino acid sequence MEPDGELSALTQGANS, which shared no similarity with any reported organophosphate-hydrolyzing enzymes. These results suggested that the purified enzyme was a novel hydrolase and might conceivably be developed to fulfill the practical requirements to enable its use in situ for detoxification of chlorpyrifos. Finally, this is the first described chlorpyrifos hydrolase from fungus.

  14. Physiological measures of neurotoxicity of diazinon and malathion to larval rainbow trout (Oncorhynchus mykiss) and their correlation with behavioral measures

    USGS Publications Warehouse

    Beauvais, S.L.; Jones, S.B.; Brewer, S.K.; Little, E.E.

    2000-01-01

    Relations between neurotoxicants and changes in physiological parameters and behavior were investigated in larval rainbow trout (RBT; Oncorhynchus mykiss) exposed to sublethal concentrations of two organophosphate pesticides (OPs). Fish were exposed to diazinon and malathion in static-renewal experiments. After exposures for 24, 96, or 96 h, followed by 48 h of recovery, individual RBT were videotaped to assess locomotory behaviors. Brain tissue from the same fish was assayed for the physiological endpoints, cholinesterase (ChE) activity, muscarinic cholinergic receptor (MChR) number (B(max)), and MChR affinity (K(D)). Cholinesterase activity decreased significantly with increasing concentrations of both diazinon and malathion and differed significantly among exposure durations, with 24- and 96-h means less than 48-h recovery means. Decreases in B(max) with OP concentration were not significant for either chemical, and K(D) was unaffected. Changes in swimming speed and distance were significantly correlated with changes in ChE activity for both chemicals; rate of turning was significantly correlated with ChE activity in malathion exposures. These results suggest that correlations between physiological and behavioral changes previously seen in mammals also occur in fish.

  15. Extraction and preconcentration of trace amounts of diazinon and fenitrothion from environmental water by magnetite octadecylsilane nanoparticles.

    PubMed

    Maddah, Bozorgmehr; Shamsi, Javad

    2012-09-21

    In this study, a method for extraction and preconcentration trace amounts of organophosphorus pesticides (OPPs) in environmental water was developed using magnetic solid phase extraction (magnetic-SPE) followed by high performance liquid chromatography (HPLC) with UV detection. Magnetite octadecylsilane nanoparticles were synthesized and characterized by X-ray diffraction, FTIR spectroscopy, vibrating sample magnetometry and scanning electron microscopy. These nanoparticles were applied for extraction and preconcentration of OPPs (residues of diazinon and fenitrothion, which are the most-widely used for pest control in Iran) in environmental water samples at low ng mL(-1) concentration as magnetic-SPE adsorbent. The extraction conditions and efficiency of the nanoparticles for OPPs were investigated. The method was evaluated according to the reproducibility, enrichment factor, linearity range and limits of detection. Under optimized conditions, method showed good linearity between 0.03-0.06 and 30 ng mL(-1) with regression coefficients (R(2)) of 0.997 and 0.998. Limits of detection were 0.019 and 0.014 ng mL(-1). The enrichment factors of this method were 172 and 184 and the analysis yielded good reproducibility with the RSD values 7.2% and 5.4% at the 10 ng mL(-1) level (n=5) for diazinon and fenitrothion, respectively. Determination of OPPs can be easily carried out with this fast, accurate, sensitive and simple method procedure.

  16. Environmental Risk Assessment of Fluctuating Diazinon Concentrations in an Urban and Agricultural Catchment Using Toxicokinetic–Toxicodynamic Modeling

    PubMed Central

    2011-01-01

    Temporally resolved environmental risk assessment of fluctuating concentrations of micropollutants is presented. We separated the prediction of toxicity over time from the extrapolation from one to many species and from acute to sublethal effects. A toxicokinetic–toxicodynamic (TKTD) model predicted toxicity caused by fluctuating concentrations of diazinon, measured by time-resolved sampling over 108 days from three locations in a stream network, representing urban, agricultural and mixed land use. We calculated extrapolation factors to quantify variation in toxicity among species and effect types based on available toxicity data, while correcting for different test durations with the TKTD model. Sampling from the distribution of extrapolation factors and prediction of time-resolved toxicity with the TKTD model facilitated subsequent calculation of the risk of undesired toxic events. Approximately one-fifth of aquatic organisms were at risk and fluctuating concentrations were more toxic than their averages. Contribution of urban and agricultural sources of diazinon to the overall risk varied. Thus using fixed concentrations as water quality criteria appears overly simplistic because it ignores the temporal dimension of toxicity. However, the improved prediction of toxicity for fluctuating concentrations may be small compared to uncertainty due to limited diversity of toxicity data to base the extrapolation factors on. PMID:21958042

  17. Environmental risk assessment of fluctuating diazinon concentrations in an urban and agricultural catchment using toxicokinetic-toxicodynamic modeling.

    PubMed

    Ashauer, Roman; Wittmer, Irene; Stamm, Christian; Escher, Beate I

    2011-11-15

    Temporally resolved environmental risk assessment of fluctuating concentrations of micropollutants is presented. We separated the prediction of toxicity over time from the extrapolation from one to many species and from acute to sublethal effects. A toxicokinetic-toxicodynamic (TKTD) model predicted toxicity caused by fluctuating concentrations of diazinon, measured by time-resolved sampling over 108 days from three locations in a stream network, representing urban, agricultural and mixed land use. We calculated extrapolation factors to quantify variation in toxicity among species and effect types based on available toxicity data, while correcting for different test durations with the TKTD model. Sampling from the distribution of extrapolation factors and prediction of time-resolved toxicity with the TKTD model facilitated subsequent calculation of the risk of undesired toxic events. Approximately one-fifth of aquatic organisms were at risk and fluctuating concentrations were more toxic than their averages. Contribution of urban and agricultural sources of diazinon to the overall risk varied. Thus using fixed concentrations as water quality criteria appears overly simplistic because it ignores the temporal dimension of toxicity. However, the improved prediction of toxicity for fluctuating concentrations may be small compared to uncertainty due to limited diversity of toxicity data to base the extrapolation factors on. PMID:21958042

  18. Determination of atrazine, lindane, pentachlorophenol, and diazinon in water and soil by isotope dilution gas chromatography/mass spectrometry

    SciTech Connect

    Lopez-Avila, V.; Hirata, P.; Kraska, S.; Flanagan, M.; Taylor, J.H. Jr.; Hern, S.C.

    1985-12-01

    This paper describes an isotope dilution GC/MS technique for the analysis of low-parts-per-billion concentrations of atrazine, lindane, pentachlorophenol, and diazinon in water and soil. Known amounts of stable-labeled isotopes such as atrazine-d/sub 5/, lindane-d/sub 6/, pentachlorophenol-/sup 13/C/sub 6/, and diazinon-d/sub 10/ are spiked into each sample prior to extraction. Water samples are extracted with methylene chloride; soil samples are extracted with acetone/hexane. Analysis is performed by high-resolution GC/MS with the mass spectrometer operated in the selected ion monitoring mode. Accuracy greater than 86% and precision better than 8% were demonstrated by use of spiked samples. This technique has been used successfully in the analysis of over 300 water and 300 soil samples. Detection limits of 0.1-1.0 ppb were achieved for the test compounds by selected ion monitoring GC/MS. 8 references, 2 figures, 4 tables.

  19. Temperature influences on water permeability and chlorpyrifos uptake in aquatic insects with differing respiratory strategies

    USGS Publications Warehouse

    Buchwalter, D.B.; Jenkins, J.J.; Curtis, L.R.

    2003-01-01

    Aquatic insects have evolved diverse respiratory strategies that range from breathing atmospheric air to breathing dissolved oxygen. These strategies result in vast morphological differences among taxa in terms of exchange epithelial surface areas that are in direct contact with the surrounding water that, in turn, affect physiological processes. This paper examines the effects of acute temperature shifts on water permeability and chlorpyrifos uptake in aquatic insects with different respiratory strategies. While considerable differences existed in water permeability among the species tested, acute temperature shifts raised water influx rates similarly in air-breathing and gill-bearing taxa. This contrasts significantly with temperature-shift effects on chlorpyrifos uptake. Temperature shifts of 4.5??C increased 14C-chlorpyrifos accumulation rates in the gill-bearing mayfly Cinygma sp. and in the air-breathing hemipteran Sigara washingtonensis. However, the temperature-induced increase in 14C-chlorpyrifos uptake after 8 h of exposure was 2.75-fold higher in Cinygma than in Sigara. Uptake of 14C-chlorpyrifos was uniformly higher in Cinygma than in Sigara in all experiments. These findings suggest that organisms with relatively large exchange epithelial surface areas are potentially more vulnerable to both osmoregulatory distress as well as contaminant accumulation. Temperature increases appear more likely to impact organisms that have relatively large exchange epithelial surface areas, both as an individual stressor and in combination with additional stressors such as contaminants.

  20. Subchronic exposure to chlorpyrifos affects energy expenditure and detoxification capacity in juvenile Japanese quails.

    PubMed

    Narváez, Cristóbal; Ríos, Juan Manuel; Píriz, Gabriela; Sanchez-Hernandez, Juan C; Sabat, Pablo

    2016-02-01

    Effects of pesticides on non-target organisms have been studied in several taxa at different levels of biological organization, from enzymatic to behavioral responses. Although the physiological responses may be associated with higher energy costs, little is known about metabolic costs of pesticide detoxification in birds. To fill this gap, we exposed orally (diet) 15-d old Coturnix coturnix japonica individuals to sublethal doses of chlorpyrifos (10 and 20 mg active ingredient/kg dry food) for four weeks. Carboxylesterase (CbE), butyrylcholinesterase (BChE) and acetylcholinesterase (AChE) activities were periodically measured in multiple tissues along with measurements of resting (RMR) and maximum metabolic rates (M(sum)). Furthermore, glucuronic acid in bird excreta was also assessed at the end of the trial. While CbE and BChE activities were inhibited by chlorpyrifos in all tissues during the third and fourth weeks following pesticide treatment, AChE activity was unaffected. At this sampling times, both M(sum) and RMR expansibility decreased. These results suggest that the exposure to chlorpyrifos caused a negative effect on aerobic performance. Additionally, excretion rate of glucuronic acid was up to 2-fold higher in the 20-mg/kg group than in the control and 10-mg/kg chlorpyrifos groups. The inhibition of CbE and BChE activities corroborated that these enzymes are fulfilling their role as bioscavengers for organophosphate pesticides, decreasing its concentration and thus protecting AChE activity against inhibition by chlorpyrifos. PMID:26414738

  1. Evaluation of chlorpyrifos transferred from contaminated feed to duck commodities and dietary risks to Chinese consumers.

    PubMed

    Li, Rui; Ji, Xiaofeng; He, Liang; Liu, Zhiqiang; Wei, Wei; Qiang, Mingrong; Wang, Qiang; Yuan, Yuwei

    2015-06-01

    The present study describes chlorpyrifos residues in duck commodities through the duck food chain, transfer factors, and dietary risks to Chinese consumers. After duck feeding experiments with pellet feed that lasted for 42 days, chlorpyrifos residues found in all samples collected from the ducks on maximum estimated dose group (3.20 mg/kg level) were from <0.0005 to 0.019 mg/kg. The residue levels of the fat, intestine, and tongue were obviously higher than those of the meat and other edible tissues. The transfer factors of all duck commodities were from 0.0001 to 0.0049 among different contamination levels, which indicated that chlorpyrifos had a low persistency in duck meat and metabolism organs. The chronic exposure assessment revealed that only 0.034-0.150% of the acceptable daily intake (ADI; 0-0.01 mg/kg/bw/day) of chlorpyrifos was consumed via the duck commodities for different age and gender groups in China. The acute exposure assessments of different age and gender groups were only 0.019-0.082% of the acute reference dose (ARfD; 0-0.1 mg/kg/bw). The results show that the single dietary exposure risk of chlorpyrifos raised by the intake of duck commodities was quite low in China. PMID:25946472

  2. Temperature influences on water permeability and chlorpyrifos uptake in aquatic insects with differing respiratory strategies.

    PubMed

    Buchwalter, David B; Jenkins, Jeffrey J; Curtis, Lawrence R

    2003-11-01

    Aquatic insects have evolved diverse respiratory strategies that range from breathing atmospheric air to breathing dissolved oxygen. These strategies result in vast morphological differences among taxa in terms of exchange epithelial surface areas that are in direct contact with the surrounding water that, in turn, affect physiological processes. This paper examines the effects of acute temperature shifts on water permeability and chlorpyrifos uptake in aquatic insects with different respiratory strategies. While considerable differences existed in water permeability among the species tested, acute temperature shifts raised water influx rates similarly in air-breathing and gill-bearing taxa. This contrasts significantly with temperature-shift effects on chlorpyrifos uptake. Temperature shifts of 4.5 degrees C increased 14C-chlorpyrifos accumulation rates in the gill-bearing mayfly Cinygma sp. and in the air-breathing hemipteran Sigara washingtonensis. However, the temperature-induced increase in 14C-chlorpyrifos uptake after 8 h of exposure was 2.75-fold higher in Cinygma than in Sigara. Uptake of 14C-chlorpyrifos was uniformly higher in Cinygma than in Sigara in all experiments. These findings suggest that organisms with relatively large exchange epithelial surface areas are potentially more vulnerable to both osmoregulatory distress as well as contaminant accumulation. Temperature increases appear more likely to impact organisms that have relatively large exchange epithelial surface areas, both as an individual stressor and in combination with additional stressors such as contaminants.

  3. Evaluation of chlorpyrifos transferred from contaminated feed to duck commodities and dietary risks to Chinese consumers.

    PubMed

    Li, Rui; Ji, Xiaofeng; He, Liang; Liu, Zhiqiang; Wei, Wei; Qiang, Mingrong; Wang, Qiang; Yuan, Yuwei

    2015-06-01

    The present study describes chlorpyrifos residues in duck commodities through the duck food chain, transfer factors, and dietary risks to Chinese consumers. After duck feeding experiments with pellet feed that lasted for 42 days, chlorpyrifos residues found in all samples collected from the ducks on maximum estimated dose group (3.20 mg/kg level) were from <0.0005 to 0.019 mg/kg. The residue levels of the fat, intestine, and tongue were obviously higher than those of the meat and other edible tissues. The transfer factors of all duck commodities were from 0.0001 to 0.0049 among different contamination levels, which indicated that chlorpyrifos had a low persistency in duck meat and metabolism organs. The chronic exposure assessment revealed that only 0.034-0.150% of the acceptable daily intake (ADI; 0-0.01 mg/kg/bw/day) of chlorpyrifos was consumed via the duck commodities for different age and gender groups in China. The acute exposure assessments of different age and gender groups were only 0.019-0.082% of the acute reference dose (ARfD; 0-0.1 mg/kg/bw). The results show that the single dietary exposure risk of chlorpyrifos raised by the intake of duck commodities was quite low in China.

  4. Potential Uses of Biomonitoring Data: A Case Study Using the Organophosphorus Pesticides Chlorpyrifos and Malathion

    PubMed Central

    Barr, Dana B.; Angerer, Jürgen

    2006-01-01

    Background Organophosphorus pesticides such as chlorpyrifos and malathion are widely used insecticides. They do not bioaccumulate appreciably in humans and are rapidly metabolized and excreted in the urine. In nonoccupational settings, exposures to these pesticides are typically sporadic and short-lived because the pesticides tend to degrade in the environment over time; however, dietary exposures may be more chronic. Biologic monitoring has been widely used to assess exposures, susceptibility, and effects of chlorpyrifos and malathion; thus, the information base on these compounds is data rich. For biomonitoring of exposure, chlorpyrifos and malathion have been measured in blood, but most typically their urinary metabolites have been measured. For assessing early effects and susceptibility, cholinesterase and microsomal esterase activities, respectively, have been measured. Objectives Although many biologic monitoring data have been generated and published on these chemicals, their interpretation is not straightforward. For example, exposure to environmental degradates of chlorpyrifos and malathion may potentially increase f urinary metabolite levels, thus leading to overestimation of exposure. Also, the temporal nature of the exposures makes the evaluation of both exposure and effects difficult. We present an overview of the current biomonitoring and other relevant data available on exposure to chlorpyrifos and malathion and the use of these data in various environmental public health applications. PMID:17107865

  5. Role of piperonyl butoxide in the toxicity of chlorpyrifos to Ceriodaphnia dubia and Xenopus laevis.

    PubMed

    El-Merhibi, A; Kumar, A; Smeaton, T

    2004-02-01

    The use of chemical inhibitors/inducers is one of the strategies employed to determine whether a particular metabolic pathway is involved in the metabolism of a xenobiotic. The objective of this study was to assess the role of piperonyl butoxide (PBO) on the toxicity of an organophosphorus insecticide, chlorpyrifos (CPF) to two species, Ceriodaphnia dubia (waterflea) and Xenopus laevis (South African clawed frog). Chlorpyrifos was highly toxic to C. dubia (48-h LC50: 0.05 microg/L) in comparison with X. laevis (96-h LC50: 2410 microg/L). Piperonyl butoxide at 200 microg/L reduced the toxicity of chlorpyrifos to C. dubia by a factor of 6. Piperonyl butoxide at 3000 microg/L also reduced the toxicity of CPF to X. laevis with respect to mortality and malformations. Acetylcholinesterase (AChE) activity was used as a biomarker to further assess the role of PBO in chlorpyrifos toxicity. X. laevis exposed to CPF and PBO exhibited a biphasic response in terms of AChE activity with an initial increase in the AChE activity followed by a drastic decrease. The results from the present study indicate that C. dubia and X. laevis have the capability to metabolize chlorpyrifos via cytochromes P450 mediated reactions. The results also indicate that the use of the biomarker AChE is useful in determining metabolic processes of organophosphorus insecticides, which require metabolic activation.

  6. Fate and effects of the insecticide chlorpyrifos in outdoor plankton-dominated microcosms in Thailand.

    PubMed

    Daam, Michiel A; Crum, Steven J H; Van den Brink, Paul J; Nogueira, António J A

    2008-12-01

    The fate and effects of the insecticide chlorpyrifos were studied in plankton-dominated, freshwater microcosms in Thailand. Disappearance rates of chlorpyrifos from the water column in the present study were similar to those in temperate regions. Insecticide accumulation in the sediment was relatively small, with the major part in the top layer (depth, 1.5 cm). Application of chlorpyrifos led to significant changes in freshwater biological communities. Clam shrimps (Conchostraca) and the cladoceran Moina micrura were the most susceptible species (no-observed-effect concentration [NOEC], 0.1 microg/L) and macroinvertebrates the most sensitive community (NOEC, 0.1 microg/L). These results are in agreement with those from semifield experiments with chlorpyrifos in temperate regions. The results of an in situ bioassay were used to calculate a NOEC of 0.1 microg/L and a 48-h median lethal concentration of 0.6 microg/L for M. micrura, which are similar to toxicity values reported for Daphnia magna in studies in temperate regions. Overall, these findings support the use of toxicity data from temperate regions for the risk assessment of low-persistent insecticides like chlorpyrifos for aquatic communities in tropical regions. PMID:18699699

  7. Susceptibility to Chlorpyrifos in Pyrethroid-Resistant Populations of Aedes aegypti (Diptera: Culicidae) from Mexico

    PubMed Central

    Lopez, Beatriz; Ponce, Gustavo; Gonzalez, Jessica A.; Gutierrez, Selene M.; Villanueva, Olga K.; Gonzalez, Gabriela; Bobadilla, Cristina; Rodriguez, Iram P.; Black, William C.; Flores, Adriana E.

    2014-01-01

    Resistance to the organophosphate insecticide chlorpyrifos was evaluated in females from six strains of Aedes aegypti (L) that expressed high levels of cross resistance to eight pyrethroid insecticides. Relative to LC50 and LC90 at 24h of a susceptible New Orleans (NO) three strains were highly resistant to chlorpyrifos (Coatzacoalcos, resistance ratio (RRLC90) =11.97; Pozarica, RRLC90=12.98; and Cosoleacaque, RRLC50= 13.94 and RRLC90=17.57), one strain was moderately resistant (Veracruz, RR=5.92), and two strains were susceptible (Tantoyuca and Martinez de la Torre, RRLC50 and RRLC90 < 5) in CDC bottle bioassays. Furthermore, high levels of α/β-esterase activity in the sample populations were correlated with resistance, suggesting that esterase activity may be a mechanism causing the development of organophosphate resistance in these populations. Overall, the populations in this study were less resistant to chlorpyrifos than to pyrethroids. Rotation of insecticides used in control activities is recommended to delay or minimize the occurrence of high levels of resistance to chlorpyrifos among local populations of Ae. aegypti. The diagnostic dose (DD) and diagnostic time (DT) for chlorpyrifos resistance monitoring was determined to be 85 μg/ bottle and 30min, respectively, using the susceptible NO strain. PMID:24897857

  8. Neurologic dysfunction and genotoxicity induced by low levels of chlorpyrifos.

    PubMed

    Muller, Mariel; Hess, Leonardo; Tardivo, Agostina; Lajmanovich, Rafael; Attademo, Andres; Poletta, Gisela; Simoniello, Maria Fernanda; Yodice, Agustina; Lavarello, Simona; Chialvo, Dante; Scremin, Oscar

    2014-12-01

    Chlorpyrifos (CPF) is an organophosphorus cholinesterase inhibitor widely used as an insecticide. Neuro and genotoxicity of this agent were evaluated following daily subcutaneous injections at 0.1, 1 and 10mg/kg or its vehicle to laboratory rats during one week, at the end of which somatosensory evoked potentials (SEP) and power spectrum of the electroencephalogram (EEGp) were recorded under urethane anesthesia. In another group of conscious animals, auditory startle reflex (ASR) was evaluated followed, after euthanasia, with measurements of plasma B-esterases, and genotoxicity with the alkaline comet assay (ACA) at the same CPF doses. The results indicated a CPF dose related inhibition of B-esterases. Enhanced inhibition of the ASR by a subthreshold pre-pulse was observed at all doses and ACA showed a significant higher DNA damage than vehicle controls in animals exposed to 10mg/kg CPF. A trend to higher frequencies of EEGp and an increase in amplitude of the first negative wave of the SEP were found at all doses. The first positive wave of the SEP decreased at the CPF dose of 10mg/kg. In summary, a shift to higher EEG frequencies and alterations of somatosensory and auditory input to the central nervous system were sensitive manifestations of CPF toxicity, associated with depression of B-esterases. The changes in electrical activity of the cerebral cortex and DNA damage observed at doses that do not elicit overt toxicity may be useful in the detection of CPF exposure before clinical signs appear.

  9. Chlorpyrifos Exposure and Respiratory Health among Adolescent Agricultural Workers

    PubMed Central

    Callahan, Catherine L.; Al-Batanony, Manal; Ismail, Ahmed A.; Abdel-Rasoul, Gaafar; Hendy, Olfat; Olson, James R.; Rohlman, Diane S.; Bonner, Matthew R.

    2014-01-01

    Chlorpyrifos (CPF) is a commonly used organophosphate insecticide (OP). In adults, exposure to OPs has been inconsistently associated with reduced lung function. OP exposure and lung function has not been assessed in adolescents. The objective of this study was to assess CPF exposure and lung function among Egyptian adolescents. We conducted a 10-month study of male adolescent pesticide applicators (n = 38) and non-applicators of similar age (n = 24). Urinary 3,5,6-trichloro-2-pyridinol (TPCy), a CPF-specific metabolite, was analyzed in specimens collected throughout the study. Spirometry was performed twice after pesticide application: day 146, when TCPy levels were elevated and day 269, when TCPy levels were near baseline. Applicators had higher levels of TCPy (mean cumulative TCPy day 146 = 33,217.6; standard deviation (SD) = 49,179.3) than non-applicators (mean cumulative TCPy day 146 = 3290.8; SD = 3994.9). Compared with non-applicators, applicators had higher odds of reporting wheeze, odds ratio = 3.41 (95% CI: 0.70; 17.41). Cumulative urinary TCPy was inversely associated with spirometric measurements at day 146, but not at day 269. Although generally non-significant, results were consistent with an inverse association between exposure to CPF and lung function. PMID:25522051

  10. Tolerance of ARPE 19 cells to organophosphorus pesticide chlorpyrifos is limited to concentration and time of exposure.

    PubMed

    Gomathy, Narayanan; Sumantran, Venil N; Shabna, A; Sulochana, K N

    2015-01-01

    Age related macular degeneration is a blinding disease common in elder adults. The prevalence of age related macular degeneration has been found to be 1.8% in the Indian population. Organophosphates are widely used insecticides with well documented neurological effects, and the persistent nature of these compounds in the body results in long term health effects. Farmers exposed to organophosphorus pesticides in USA had an earlier onset of age related macular degeneration when compared to unexposed controls. A recent study found significant levels of an organophosphate, termed chlorpyrifos, in the blood samples of Indian farmers. Therefore, in understanding the link between age related macular degeneration and chlorpyrifos, the need for investigation is important. Our data show that ARPE-19 (retinal pigment epithelial cells) exhibit a cytoprotective response to chlorpyrifos as measured by viability, mitochondrial membrane potential, superoxide dismutase activity, and increased levels of glutathione peroxidase and reduced glutathione, after 24 h exposure to chlorpyrifos. However, this cytoprotective response was absent in ARPE-19 cells exposed to the same range of concentrations of chlorpyrifos for 48 h. These results have physiological significance, since HPLC analysis showed that effects of chlorpyrifos were mediated through its entry into ARPE-19 cells. HPLC analysis also showed that chlorpyrifos remained stable, as we recovered up to 80% of the chlorpyrifos added to 6 different ocular tissues. PMID:25619908

  11. USE OF PHARMACOKINETIC MODEL TO ASSESS CHLORPYRIFOS EXPOSURE AND DOSE IN CHILDREN BASED ON URINARY BIOMARKER MEASUREMENTS

    EPA Science Inventory

    Chlorpyrifos is a common agricultural insecticide and has been used residentially in the United States until 2000 when this use was restricted by the U.S. Environmental Protection Agency (U.S. EPA). A chlorpyrifos metabolite, 3,5,6-trichloro-2-pyridinol (TCPy) has been found i...

  12. Isolation of a chlorpyrifos-degrading bacterium, Sphingomonas sp. strain Dsp-2, and cloning of the mpd gene.

    PubMed

    Li, Xiaohui; He, Jian; Li, Shunpeng

    2007-03-01

    A highly effective chlorpyrifos-degrading bacterium strain Dsp-2 was isolated from the polluted treatment system of a chlorpyrifos manufacturer. This strain was preliminarily identified as Sphingomonas sp. based on its morphological, physiological and biochemical tests as well as 16S rDNA analysis. It utilized chlorpyrifos as its sole source of carbon for growth, by hydrolyzing chlorpyrifos to 3,5,6-trichloro-2-pyridinol (TCP). It could also utilize parathion, parathion-methyl, fenitrothion and profenofos, but not phoxin and triazophos. Bioremediation of chlorpyrifos-contaminated soil was examined using Dsp-2. Dsp-2 addition to soil treated with 100mgkg(-1) chlorpyrifos resulted in a higher degradation rate than control soils without inoculation. The moderate pH, moisture and inoculum density could have promoted degradation. The gene encoding the chlorpyrifos hydrolytic enzyme was cloned by PCR. Although BLAST sequence search results indicated that this gene has 99% similarity to mpd (a gene encoding the parathion-methyl hydrolyzing enzyme in Plesiomonas sp. M6), its hydrolytic efficiency for chlorpyrifos was significantly greater than the wild-type mpd from strain M6. PMID:17306510

  13. Solvent-assisted dispersive solid-phase extraction: A sample preparation method for trace detection of diazinon in urine and environmental water samples.

    PubMed

    Aladaghlo, Zolfaghar; Fakhari, Alireza; Behbahani, Mohammad

    2016-09-01

    In this research, a sample preparation method termed solvent-assisted dispersive solid-phase extraction (SA-DSPE) was applied. The used sample preparation method was based on the dispersion of the sorbent into the aqueous sample to maximize the interaction surface. In this approach, the dispersion of the sorbent at a very low milligram level was received by inserting a solution of the sorbent and disperser solvent into the aqueous sample. The cloudy solution created from the dispersion of the sorbent in the bulk aqueous sample. After pre-concentration of the diazinon, the cloudy solution was centrifuged and diazinon in the sediment phase dissolved in ethanol and determined by gas chromatography-flame ionization detector. Under the optimized conditions (pH of solution=7.0, Sorbent: benzophenone, 2%, Disperser solvent: ethanol, 500μL, Centrifuge: centrifuged at 4000rpm for 3min), the method detection limit for diazinon was 0.2, 0.3, 0.3 and 0.3μgL(-1) for distilled water, lake water, waste water and urine sample, respectively. Furthermore, the pre-concentration factor was 363.8, 356.1, 360.7 and 353.38 in distilled water, waste water, lake water and urine sample, respectively. SA-DSPE was successfully used for trace monitoring of diazinon in urine, lake and waste water samples. PMID:27495366

  14. The effect of stress on the acute neurotoxicity of the organophosphate insecticide chlorpyrifos

    SciTech Connect

    Hancock, Sandra; Ehrich, Marion; Hinckley, Jonathan; Pung, Thitiya; Jortner, Bernard S. . E-mail: bjortner@vt.edu

    2007-03-15

    A study was conducted to determine if multiple exposures to several stress paradigms might affect the anticholinesterase effect of subsequently administered organophosphate insecticide chlorpyrifos. Male Sprague-Dawley rats were subject to daily periods of restraint, swimming, a combination of the two, or neither of the two (controls) (n = 8/group) for 5 days per week over a six-week period. The most profound stress, as measured by reduced body weight gain and elevated levels of plasma corticosterone, was swimming. On day 39 of the study, shortly after the daily stress episode, one half of the rats in each group was dosed with 60 mg/kg chlorpyrifos subcutaneously. This had no effect on subsequent levels of plasma corticosterone. There were no stress-related differences in the degree of chlorpyrifos-induced inhibition of brain acetylcholinesterase in animals sacrificed on day 43.

  15. Analysis of AchE and LDH in mollusc, Lamellidens marginalis after exposure to chlorpyrifos.

    PubMed

    Amanullah, B; Stalin, A; Prabu, P; Dhanapal, S

    2010-07-01

    The enzymes Acetylcholinesterase (AchE) and Lactatedehydrogenase (LDH) are used as biological markers in the present study. Enzymes are highly sensitive and used to evaluate the biological effects of organophosphate pesticide chlorpyrifos in freshwater mussel Lamellidens marginalis. The test organisms were exposed to sub-lethal concentration (5 ppm) of chlorpyrifos for 30 days and allowed to recover for seven days. A distinct reduction of the enzyme AchE (34 +/- 3.3 U l(-1)) was found in the treated hepatopancreas. A significant increase in LDH activity in gill, hepatopancreas and muscle was observed. There was a significant recovery in AchE and LDH in the different tissues, after seven days recovery period.. Hence, the changes in the enzymes are found as the best biomarkering tool to evaluate the effect of organophosphate pesticide chlorpyrifos on the aquatic biota.

  16. Identification and functional characteristics of chlorpyrifos-degrading and plant growth promoting bacterium Acinetobacter calcoaceticus.

    PubMed

    Zhao, Lei; Wang, Fei; Zhao, Jiao

    2014-05-01

    A bacterial strain D10 with strong ability of degrading chlorpyrifos was isolated from rhizosphere of chives contaminated with pesticide. It was found that it's capable of utilizing chlorpyrifos as the sole source of carbon for growth, and within the first 4 days the extent of degradation at initial concentration of 100 mg L(-1) was 60.0%. It also showed a high ability of degrading chlorpyrifos in sterilized soil, and the degradation reached up to 60.2% after 18 days. In addition, the strain D10 also showed multiple plant growth-promoting traits of phosphate solubilization, indole-3-acetic acid and siderophore production. The results indicate that the strain D10 has potential in the application of pesticide-degrading and plant growth promotion. Strain D10 was identified as Acinetobacter calcoaceticus based on its morphological, physiological-biochemical properties and the 16S rRNA sequence analysis.

  17. Chlorpyrifos residual behaviors in field crops and transfers during duck pellet feed processing.

    PubMed

    Li, Rui; Wei, Wei; He, Liang; Hao, Lili; Ji, Xiaofeng; Zhou, Yu; Wang, Qiang

    2014-10-22

    Chlorpyrifos is a widely used organophosphorus pesticide in agricultural crops (including food) and animal feeds in China, resulting in heavy contamination. Many studies have focused on the food-processing effects on chlorpyrifos removal, but sufficient information is not observed for feed-processing steps. Here, chlorpyrifos residual behaviors in field crops and its transfers in duck pellet feed-processing steps were evaluated. In field trials, the highest residues for rice grain, shelled corn, and soybean seed were 12.0, 0.605, and 0.220 mg/kg, respectively. Residues of all rice grain and about half of shelled corn exceeded the maximum residue limits (MRLs) of China, and five soybean seeds exceeded the MRL of China. Chlorpyrifos residue was reduced 38.2% in brown rice after the raw rice grain was hulled. The residue in bran increased 71.2% after milling from brown rice. During the squashing step, the residue reduced 73.8% in soybean meal. The residues reduced significantly (23.7-36.8%) during the process of granulating for rice, maize, and soybean products. Comparatively, the grinding process showed only limited influence on chlorpyrifos removal (<10%). The residues of duck pellet feeds produced from highly contaminated raw materials of this study were 1.01 mg/kg (maize-soybean feed) and 3.20 mg/kg (rice-soybean feed), which were much higher than the generally accepted value (>0.1 mg/kg) for animal feeding. Chlorpyrifos residues were removed significantly by processing steps of pellet feeds, but the residue of raw materials was the determining factor for the safety of duck feeding. PMID:25310710

  18. [Effects of single and co-exposure of Cu and chlorpyrifos on the toxicity of earthworm].

    PubMed

    Xu, Dong-mei; Wang, Yan-hua; Wang, Nan; Rao, Gui-wei

    2015-01-01

    Combined pollution of heavy metal and pesticide had posed a serious threat to soil ecology and human living environment. As two common types of pollutants in soil environment, the environmental effects of combined pollution of Cu and chlorpyrifos are worth for attention. The acute lethal effects and avoiding behavior of single and co-exposure of Cu and chlorpyrifos on earthworms were analyzed by using the methods of standard OECD filter paper test and artificial soil test. Results showed that the LC(50,48 h) and LC(50,14 d) of the acute toxicity of Cu on earthworm in filter paper test and in artificial soil test were 2.23 microg x cm(-2) and 496.05 mg x kg(-1), respectively. The LC(50,48 h) and LC(50,14 d) of the acute toxicity of chlorpyrifos on earthworm in filter paper test and in artificial soil test were 5.94 microg x cm(-2) and 186.07 mg x kg(-1), respectively. In filter paper test and artificial soil test, the joint acute toxicity of Cu and chlorpyrifos showed an additive effect while the concentration was 1:1. The type of combined effects of co-exposure of Cu and chlorpyrifos was synergistic effect and antagonistic effect in filter paper test and artificial soil test, respectively, while the toxicity was 1:1. The results of avoidance behavior test showed that the joint effect of Cu and chlorpyrifos on the avoidance behavior of earthworms was antagonistic. PMID:25898676

  19. Potential of Agricultural By-product in Reducing Chlorpyrifos Leaching Through Soil

    NASA Astrophysics Data System (ADS)

    Romyen, Siraprapa; Luepromchai, Ekawan; Hawker, Darryl; Karnchanasest, Benjalak

    This study was conducted to determine the minimization of chlorpyrifos, an organophosphate pesticide, in leachate after spraying onto plants by agricultural by-product. Agricultural by-product samples including coconut husk, peat moss, rice husk and peanut shell were investigated in comparison to a sandy soil sample taken from orange grove. Batch partitioning experiments were initially conducted to evaluate sorption capacity of these sorbents. The experiments revealed that peat moss could sorp chlorpyrifos higher than coconut husk, rice husk and peanut shell, respectively. For soil, sorption obviously gave lower values than all agricultural-by product samples. Sorption coefficient (KD) values were increased with increasing organic carbon contents in sorbent, which indicated that organic carbon played an important role in sorption of chlorpyrifos. Half-life (t1/2) of chlorpyrifos in coconut husk was 8.6 days, which was reported to be the fastest among the tested biomass, whereas; its half-life was 56.8 days in soil. The results suggested that the sorped chlopyrifos could be degraded afterward. To find the optimum depth before use in the field, leaching experiments were carried out by packing 2, 3 and 4 cm coconut husk in columns and sprayed with 0.25 kg haG1 chlorpyrifos to the column surface. Results indicated that 97.02, 99.62 and 99.96% of chlorpyrifos mass could be retained in coconut husk at 2, 3 and 4 cm depth, respectively. Therefore, coconut husk was recommended as sorbent material due to the combination of high sorption capacity and enhanced biodegradation properties.

  20. Dissipation kinetics and assessment of processing factor for chlorpyrifos and lambda-cyhalothrin in cardamom.

    PubMed

    George, Thomas; Beevi, S Naseema; Xavier, George; Kumar, N Pratheesh; George, Jayesh

    2013-06-01

    The dissipation kinetics and method for estimation of residues of chlorpyrifos and lambda-cyhalothrin in cardamom were studied and developed. The limit of detection and limit of quantitation arrived for the compounds were 0.01 and 0.025 μg g(-1), respectively. Gas chromatographic response of chlorpyrifos and lambda-cyhalothrin residues was linear in the range of 0.01-0.50 μg g(-1) and the mean recovery obtained was 97.3 % for chlorpyrifos and 98.9 % for lambda-cyhalothrin with satisfactory relative standard deviation values. The mean initial residues of chlorpyrifos applied at a concentration of 0.05 % in cardamom was 2.5 μg g(-1) and the residue was 8.1 μg g(-1) after processing, with a processing factor of 3.24, while lambda-cyhalothrin when applied at 0.0025 % resulted in initial residues of 1.63 μg g(-1) that magnified to 4.86 μg g(-1) on curing, with a processing factor of 2.98. The half-life of chlorpyrifos was in the range of 5.1-5.24 days while that of lambda-cyhalothrin was in the range of 4.40-4.55 days. The processing factor arrived at in the above experiment lead to the conclusion that the residues of chlorpyrifos got magnified to 3.24-3.68 times and that of lambda-cyhalothrin got magnified to 2.98-3.46 times of initial residues, consequent to loss of weight due to dehydration during curing. PMID:23079795

  1. Oxidative mechanisms contributing to the developmental neurotoxicity of nicotine and chlorpyrifos

    SciTech Connect

    Qiao, Dan; Seidler, Frederic J.; Slotkin, Theodore A. . E-mail: t.slotkin@duke.edu

    2005-08-01

    Nicotine and chlorpyrifos are developmental neurotoxicants that, despite their differences in structure and mechanism of action, share many aspects for damage to the developing brain. Both are thought to generate oxidative radicals; in the current study, we evaluated their ability to produce lipid peroxidation in two in vitro models of neural cell development (PC12 and SH-SY5Y cells) and for nicotine, with treatment of adolescent rats in vivo. Nicotine and chlorpyrifos, in concentrations relevant to human exposures, elicited an increase in thiobarbituric-acid-reactive species (TBARS) in undifferentiated cells, an effect that was prevented by addition of the antioxidant, Vitamin E. Initiating differentiation with nerve growth factor, which enhances nicotinic acetylcholine receptor expression, increased the TBARS response to nicotine but not chlorpyrifos, suggesting that the two agents act by different originating mechanisms to converge on the endpoint of oxidative damage. Furthermore, nicotine protected the cells from oxidative damage evoked by chlorpyrifos and similarly blocked the antimitotic effect of chlorpyrifos. Treatment of adolescent rats with nicotine elicited increases in TBARS in multiple brain regions when given in doses that simulate plasma nicotine concentrations found in smokers or at one-tenth the dose. Our results indicate that nicotine and chlorpyrifos elicit oxidative damage to developing neural cells both in vitro and in vivo, a mechanism that explains some of the neurodevelopmental endpoints that are common to the two agents. The balance between neuroprotectant and neurotoxicant actions of nicotine may be particularly important in situations where exposure to tobacco smoke is combined with other prooxidant insults.

  2. Warming increases chlorpyrifos effects on predator but not anti-predator behaviours.

    PubMed

    Dinh Van, Khuong; Janssens, Lizanne; Debecker, Sara; Stoks, Robby

    2014-07-01

    Recent insights indicate that negative effects of pesticides on aquatic biota occur at concentrations that current legislation considers environmentally protective. We here address two, potentially interacting, mechanisms that may contribute to the underestimation of the impact of sublethal pesticide effects in single species tests at room temperature: the impairment of predator and antipredator behaviours and the stronger impact of organophosphate pesticides at higher temperatures. To address these issues we assessed the effects of chlorpyrifos on the predator and antipredator behaviours of larvae of the damselfly Ischnura elegans, important intermediate predators in aquatic food webs, in a common-garden warming experiment with replicated low- and high-latitude populations along the latitudinal gradient of this species in Europe. Chlorpyrifos reduced the levels of predator behavioural endpoints, and this reduction was stronger at the higher temperature for head orientations and feeding strikes. Chlorpyrifos also impaired two key antipredator behavioural endpoints, activity reductions in response to predator cues were smaller in the presence of chlorpyrifos, and chlorpyrifos caused a lower escape swimming speed; these effects were independent of temperature. This suggests chlorpyrifos may impact food web interactions by changing predator-prey interactions both with higher (predators) and lower trophic levels (food). Given that only the interaction with the lower trophic level was more impaired at higher temperatures, the overall pesticide-induced changes in food web dynamics may be strongly temperature-dependent. These findings were consistent in damselflies from low- and high-latitude populations, illustrating that thermal adaptation will not mitigate the increased toxicity of pesticides at higher temperatures. Our study not only underscores the relevance of including temperature and prey-predator interactions in ecological risk assessment but also their potential

  3. Oxidative mechanisms contributing to the developmental neurotoxicity of nicotine and chlorpyrifos.

    PubMed

    Qiao, Dan; Seidler, Frederic J; Slotkin, Theodore A

    2005-08-01

    Nicotine and chlorpyrifos are developmental neurotoxicants that, despite their differences in structure and mechanism of action, share many aspects for damage to the developing brain. Both are thought to generate oxidative radicals; in the current study, we evaluated their ability to produce lipid peroxidation in two in vitro models of neural cell development (PC12 and SH-SY5Y cells) and for nicotine, with treatment of adolescent rats in vivo. Nicotine and chlorpyrifos, in concentrations relevant to human exposures, elicited an increase in thiobarbituric-acid-reactive species (TBARS) in undifferentiated cells, an effect that was prevented by addition of the antioxidant, Vitamin E. Initiating differentiation with nerve growth factor, which enhances nicotinic acetylcholine receptor expression, increased the TBARS response to nicotine but not chlorpyrifos, suggesting that the two agents act by different originating mechanisms to converge on the endpoint of oxidative damage. Furthermore, nicotine protected the cells from oxidative damage evoked by chlorpyrifos and similarly blocked the antimitotic effect of chlorpyrifos. Treatment of adolescent rats with nicotine elicited increases in TBARS in multiple brain regions when given in doses that simulate plasma nicotine concentrations found in smokers or at one-tenth the dose. Our results indicate that nicotine and chlorpyrifos elicit oxidative damage to developing neural cells both in vitro and in vivo, a mechanism that explains some of the neurodevelopmental endpoints that are common to the two agents. The balance between neuroprotectant and neurotoxicant actions of nicotine may be particularly important in situations where exposure to tobacco smoke is combined with other prooxidant insults. PMID:15963341

  4. Exposure to low doses of endosulfan and chlorpyrifos modifies endogenous antioxidants in tissues of rats.

    PubMed

    Bebe, Frederick N; Panemangalore, Myna

    2003-05-01

    Two experiments were conducted in male SD rats (225-250 g) to determine changes in the activities of endogenous antioxidants superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) and concentrations of glutathione (GSH) in tissues after exposure to low doses of endosulfan and chlorpyrifos using a whole body exposure technique. In both experiments, 6 rats/group were exposed 3 hr/day, 5 days/week for 30 days to: 0 (control), 5, 10, 20, 40 and 60% of LD50 of either pesticide in 50% ethanol; actual concentrations were: endosulfan = 0, 0.5, 1.0, 2.0, 4.0, 6.0 mg/250 g body weight; chlorpyrifos = 0, 1.9, 3.8, 7.6, 15.2, and 22.8 mg/250 g body weight. Endosulfan decreased erythrocyte SOD by 21% in all groups and chlorpyrifos increased SOD by 18% in groups 40 and 60. Liver SOD was 12%-20% lower after endosulfan exposure; lung SOD was altered: endosulfan decreased activity by 21% and 51% and chlorpyrifos by 58 and 75% in the 40 and 60 groups, respectively (P < or = 0.05). Both pesticides increased plasma GPX activity at lower levels and reduced it by 26% and 19% in groups 40 and 60, respectively (P < or = 0.05). Liver GPX increased in the 60 group and lung GPX declined between 20% and 38% after endosulfan exposure. GSH in the liver and lung: endosulfan reduced GSH by about 30% at lower levels and increased by 41% or 70% at higher levels; chlorpyrifos decreased GSH by 28-40% in 20 and 60 groups, respectively (P < or = 0.05). Exposure to low, increasing levels of endosulfan and chlorpyrifos can differentially modify endogenous antioxidants SOD, GPX and GSH, which may lead to the development of oxidative stress in some tissues.

  5. Developmental sub-chronic exposure to chlorpyrifos reduces anxiety-related behavior in zebrafish larvae

    PubMed Central

    Richendrfer, Holly; Pelkowski, Sean D.; Colwill, Ruth M.; Créton, Robbert

    2013-01-01

    Neurobehavioral disorders such as anxiety, autism, and attention deficit hyperactivity disorders are typically influenced by genetic and environmental factors. Although several genetic risk factors have been identified in recent years, little is known about the environmental factors that either cause neurobehavioral disorders or contribute to their progression in genetically predisposed individuals. One environmental factor that has raised concerns is chlorpyrifos, an organophosphate pesticide that is widely used in agriculture and is found ubiquitously in the environment. In the present study, we examined the effects of sub-chronic chlorpyrifos exposure on anxiety-related behavior during development using zebrafish larvae. We found that sub-chronic exposure to 0.01 or 0.1 μM chlorpyrifos during development induces specific behavioral defects in 7-day-old zebrafish larvae. The larvae displayed decreases in swim speed and thigmotaxis, yet no changes in avoidance behavior were seen. Exposure to 0.001 μM chlorpyrifos did not affect swimming, thigmotaxis, or avoidance behavior and exposure to 1 μM chlorpyrifos induced behavioral defects, but also induced defects in larval morphology. Since thigmotaxis, a preference for the edge, is an anxiety-related behavior in zebrafish larvae, we propose that sub-chronic chlorpyrifos exposure interferes with the development of anxiety-related behaviors. The results of this study provide a good starting point for examination of the molecular, cellular, developmental, and neural mechanisms that are affected by environmentally relevant concentrations of organophosphate pesticides. A more detailed understanding of these mechanisms is important for the development of predictive models and refined health policies to prevent toxicant-induced neurobehavioral disorders. PMID:22579535

  6. Dissipation kinetics and assessment of processing factor for chlorpyrifos and lambda-cyhalothrin in cardamom.

    PubMed

    George, Thomas; Beevi, S Naseema; Xavier, George; Kumar, N Pratheesh; George, Jayesh

    2013-06-01

    The dissipation kinetics and method for estimation of residues of chlorpyrifos and lambda-cyhalothrin in cardamom were studied and developed. The limit of detection and limit of quantitation arrived for the compounds were 0.01 and 0.025 μg g(-1), respectively. Gas chromatographic response of chlorpyrifos and lambda-cyhalothrin residues was linear in the range of 0.01-0.50 μg g(-1) and the mean recovery obtained was 97.3 % for chlorpyrifos and 98.9 % for lambda-cyhalothrin with satisfactory relative standard deviation values. The mean initial residues of chlorpyrifos applied at a concentration of 0.05 % in cardamom was 2.5 μg g(-1) and the residue was 8.1 μg g(-1) after processing, with a processing factor of 3.24, while lambda-cyhalothrin when applied at 0.0025 % resulted in initial residues of 1.63 μg g(-1) that magnified to 4.86 μg g(-1) on curing, with a processing factor of 2.98. The half-life of chlorpyrifos was in the range of 5.1-5.24 days while that of lambda-cyhalothrin was in the range of 4.40-4.55 days. The processing factor arrived at in the above experiment lead to the conclusion that the residues of chlorpyrifos got magnified to 3.24-3.68 times and that of lambda-cyhalothrin got magnified to 2.98-3.46 times of initial residues, consequent to loss of weight due to dehydration during curing.

  7. Prenatal dexamethasone augments the neurobehavioral teratology of chlorpyrifos: significance for maternal stress and preterm labor.

    PubMed

    Levin, Edward D; Cauley, Marty; Johnson, Joshua E; Cooper, Ellen M; Stapleton, Heather M; Ferguson, P Lee; Seidler, Frederic J; Slotkin, Theodore A

    2014-01-01

    Glucocorticoids are the consensus treatment given in preterm labor and are also elevated by maternal stress; organophosphate exposures are virtually ubiquitous, so human developmental coexposures to these two agents are common. This study explores how prenatal dexamethasone exposure modifies the neurobehavioral teratology of chlorpyrifos, one of the most widely used organophosphates. We administered dexamethasone to pregnant rats on gestational days 17-19 at a standard therapeutic dose (0.2 mg/kg); offspring were then given chlorpyrifos on postnatal days 1-4, at a dose (1 mg/kg) that produces barely-detectable (<10%) inhibition of brain cholinesterase activity. Dexamethasone did not alter brain chlorpyrifos concentrations, nor did either agent alone or in combination affect brain thyroxine levels. Assessments were carried out from adolescence through adulthood encompassing T-maze alternation, Figure 8 maze (locomotor activity, habituation), novelty-suppressed feeding and novel object recognition tests. For behaviors where chlorpyrifos or dexamethasone individually had small effects, the dual exposure produced larger, significant effects that reflected additivity (locomotor activity, novelty-suppressed feeding, novel object recognition). Where the individual effects were in opposite directions or were restricted to only one agent, we found enhancement of chlorpyrifos' effects by prenatal dexamethasone (habituation). Finally, for behaviors where controls displayed a normal sex difference in performance, the combined treatment either eliminated or reversed the difference (locomotor activity, novel object recognition). Combined exposure to dexamethasone and chlorpyrifos results in a worsened neurobehavioral outcome, providing a proof-of-principle that prenatal glucocorticoids can create a subpopulation with enhanced vulnerability to environmental toxicants.

  8. Reactive oxygen species regulated mitochondria-mediated apoptosis in PC12 cells exposed to chlorpyrifos

    SciTech Connect

    Lee, Jeong Eun; Park, Jae Hyeon; Shin, In Chul; Koh, Hyun Chul

    2012-09-01

    Reactive oxidative species (ROS) generated by environmental toxicants including pesticides could be one of the factors underlying the neuronal cell damage in neurodegenerative diseases. In this study we found that chlorpyrifos (CPF) induced apoptosis in dopaminergic neuronal components of PC12 cells as demonstrated by the activation of caspases and nuclear condensation. Furthermore, CPF also reduced the tyrosine hydroxylase-positive immunoreactivity in substantia nigra of the rat. In addition, CPF induced inhibition of mitochondrial complex I activity. Importantly, N-acetyl cysteine (NAC) treatment effectively blocked apoptosis via the caspase-9 and caspase-3 pathways while NAC attenuated the inhibition of mitochondrial complex I activity as well as the oxidative metabolism of dopamine (DA). These results demonstrated that CPF-induced apoptosis was involved in mitochondrial dysfunction through the production of ROS. In the response of cellular antioxidant systems to CPF, we found that CPF treatment increased HO-1 expression while the expression of CuZnSOD and MnSOD was reduced. In addition, we found that CPF treatment activated MAPK pathways, including ERK 1/2, the JNK, and the p38 MAP kinase in a time-dependent manner. NAC treatment abolished MAPK phosphorylation caused by CPF, indicating that ROS are upstream signals of MAPK. Interestingly, MAPK inhibitors abolished cytotoxicity and reduced ROS generation by CPF treatment. Our results demonstrate that CPF induced neuronal cell death in part through MAPK activation via ROS generation, suggesting its potential to generate oxidative stress via mitochondrial damage and its involvement in oxidative stress-related neurodegenerative disease. -- Highlights: ► Chlorpyrifos induces apoptosis. ► Chlorpyrifos inhibits mitochondrial complex I activity. ► ROS is involved in chlorpyrifos-induced apoptosis. ► Chlorpyrifos affects cellular antioxidant systems. ► Chlorpyrifos-induced apoptosis mediates activation of MAPK.

  9. Warming increases chlorpyrifos effects on predator but not anti-predator behaviours.

    PubMed

    Dinh Van, Khuong; Janssens, Lizanne; Debecker, Sara; Stoks, Robby

    2014-07-01

    Recent insights indicate that negative effects of pesticides on aquatic biota occur at concentrations that current legislation considers environmentally protective. We here address two, potentially interacting, mechanisms that may contribute to the underestimation of the impact of sublethal pesticide effects in single species tests at room temperature: the impairment of predator and antipredator behaviours and the stronger impact of organophosphate pesticides at higher temperatures. To address these issues we assessed the effects of chlorpyrifos on the predator and antipredator behaviours of larvae of the damselfly Ischnura elegans, important intermediate predators in aquatic food webs, in a common-garden warming experiment with replicated low- and high-latitude populations along the latitudinal gradient of this species in Europe. Chlorpyrifos reduced the levels of predator behavioural endpoints, and this reduction was stronger at the higher temperature for head orientations and feeding strikes. Chlorpyrifos also impaired two key antipredator behavioural endpoints, activity reductions in response to predator cues were smaller in the presence of chlorpyrifos, and chlorpyrifos caused a lower escape swimming speed; these effects were independent of temperature. This suggests chlorpyrifos may impact food web interactions by changing predator-prey interactions both with higher (predators) and lower trophic levels (food). Given that only the interaction with the lower trophic level was more impaired at higher temperatures, the overall pesticide-induced changes in food web dynamics may be strongly temperature-dependent. These findings were consistent in damselflies from low- and high-latitude populations, illustrating that thermal adaptation will not mitigate the increased toxicity of pesticides at higher temperatures. Our study not only underscores the relevance of including temperature and prey-predator interactions in ecological risk assessment but also their potential

  10. Ecotoxicity of two organophosphate pesticides chlorpyrifos and dichlorvos on non-targeting cyanobacteria Microcystis wesenbergii.

    PubMed

    Sun, Kai-Feng; Xu, Xiang-Rong; Duan, Shun-Shan; Wang, You-Shao; Cheng, Hao; Zhang, Zai-Wang; Zhou, Guang-Jie; Hong, Yi-Guo

    2015-10-01

    Organophosphate pesticides (OPs), as a replacement for the organochlorine pesticides, are generally considered non-toxic to plants and algae. Chlorpyrifos and dichlorvos are two OPs used for pest control all over the world. In this study, the dose-response of cyanobacteria Microcystis wesenbergii on OPs exposure and the stimulating effect of OPs with and without phosphorus source were investigated. The results showed that high concentrations of chlorpyrifos and dichlorvos caused significant decrease of chlorophyll a content. The median inhibitory concentrations (EC50) of chlorpyrifos and dichlorvos at 96 h were 15.40 and 261.16 μmol L(-1), respectively. Growth of M. wesenbergii under low concentration of OPs (ranged from 1/10,000 to 1/20 EC50), was increased by 35.85 % (chlorpyrifos) and 41.83 % (dichlorvos) at 120 h, respectively. Correspondingly, the highest enhancement on the maximum quantum yield (F v/F m) was 4.20 % (24 h) and 9.70 % (48 h), respectively. Chlorophyll fluorescence kinetics, known as O-J-I-P transients, showed significant enhancements in the O-J, J-I, and I-P transients under low concentrations of dichlorvos at 144 h, while enhancements of chlorophyll fluorescence kinetics induced by low concentrations of chlorpyrifos were only observed in the J-I transient at 144 h. Significant decreases of chlorophyll content, F v/F m and O-J-I-P transients with OPs as sole phosphorus source were found when they were compared with inorganic phosphate treatments. The results demonstrated an evidently hormetic dose-response of M. wesenbergii to both chlorpyrifos and dichlorvos, where high dose (far beyond environmental concentrations) exposure caused growth inhibition and low dose exposure induced enhancement on physiological processes. The stimulating effect of two OPs on growth of M. wesenbergii was negligible under phosphate limitation.

  11. Chlorpyrifos reduces nickel-induced growth retardation of the soil dwelling Collembolan Folsomia candida.

    PubMed

    Broerse, Mieke; van Gestel, Cornelis A M

    2010-07-01

    For 7 weeks, we studied the effects on body size and growth rate of Folsomia candida exposed to nickel and chlorpyrifos and their mixtures in a natural Lufa 2.2 soil. Nickel significantly reduced the development of body size of the springtails, although no complete dose-response curve was obtained. Chlorpyrifos did not influence the springtail growth when applied alone, but significantly reduced the growth retardation induced by nickel. We showed that by monitoring the development of toxicity in time for both the single compounds and the mixtures it was possible to determine mixture interactions even when no complete dose-response curves were available for all mixture components. PMID:20185177

  12. [Physiological response of Neocaridina denticulate to the toxicity of Cu2+ and chlorpyrifos].

    PubMed

    Li, Dian-Bao; Zhang, Wei; Wang, Li-Qing; Zhang, Rui-Lei; Ji, Gao-Hua

    2015-02-01

    In order to study the physiological response to heavy metals and organic-phosphorus pesticide toxicity of aquatic organisms, Neocaridina denticulate was used as a test organism to investigate the impact of physiological indices of N. denticulate muscle tissues when they were exposed to Cu2+ and chlorpyrifos for 5 days respectively with the test methods of semi-static toxicity. The results showed that: when exposed to different concentrations of Cu2+ and chlorpyrifos solutions, the protein concentrations in muscle tissues were significantly lower with the extension of time to varying degrees. In the lower concentration groups of Cu2+ (0.086 mg x L(-1) and 0.172 mg-L-') and the higher concentration groups of chlorpyrifos (0. 006 0 [g-L-' and 0.012 0 μg x L(-1)), the total SOD activity showed inhibitory effect; the trend of the higher concentration group of Cu2+ (0.344 mg x L(-1) and 0.688 mg x L(-1)) showed " inhibition-promotion-inhibition", however, the lower concentration groups of chlorpyrifos (0.001 5 μg x L(-1) and 0.003 0 μg x L(-1)) showed the" inhibition-promotion" changes in trends; MDA contents changed similarly, and within a certain range of concentrations, MDA contents presented a gradually rising trend with increasing Cu2+ and chlorpyrifos concentration, which indicated that Cu2+ and chlorpyrifos accelerated lipid, peroxidation in muscle tissues of N. denticulate. In addition, AChE activity in Cu2+ and chlorpyrifos solutions showed inhibitory effect, and in the solutions with higher concentration of Cu2+ and chlorpyrifos, the activity was gradually decreased with the increase of concentration, indicating that Cu2+ and chlorpyrifoscs impacted the normal physiological functions of N. denticulate, and the higher the concentration, the greater the damage effect. Based on the analysis results, we confirmed that the total SOD, MDA and AChE played significant roles as physiological indicators in evaluating toxic effect of heavy metals and organic

  13. [Preliminary investigation of four anopheles larvae samples susceptibility to chlorpyrifos in Tunisia].

    PubMed

    Krida, G; Bouattour, A; Rhaim, A; el Kebir, A; Jlidi, R

    1998-01-01

    Larvae susceptibility to chlorpyrifos is studied on four Tunisian Anopheles larvas samples: Anopheles labranchiae from Rades (South of Tunis) and Menchar (region of Beja), in the North of Tunisia, A. sergentii from Meknassy and A. multicolor from Sidi Bouzid, both in the Centre of Tunisia. The test results of larvae susceplibility indicate that the LC50 and the LC95 values are less than 0.002 and 0.02 mg l-1 respectively and their 95% confidence limits overlap. We also notice that the studied samples show the same susceptibility to chlorpyrifos. The results can be used as a base data further studies on the susceptibility of Anopheles to chemical insecticides.

  14. [Evidence of very high resistance to chlorpyrifos and permethrin in Culex pipiens populations in Tunisia].

    PubMed

    Ben Cheikh, H; Marrakchi, M; Pasteur, N

    1995-01-01

    Resistance to two organophosphorous insecticides (temephos and chlorpyrifos) and one pyrethrinoid (permethrin) was studied in larvae of five Culex pipiens samples collected in Gafsa, Telalsa, Sayada, Monastir et Sfax. Large variations in the tolerance to these insecticides was observed between samples. Gafsa sample was the most susceptible and disclosed little difference when compared to the susceptible reference strain. In contrast, at LD95 the resistance ratio (RR) was 8 folds with temephos, 9000 folds with chlorpyrifos, and 1500 folds with permethrin in the Sfax sample. These results are discussed in relation to resistance mechanisms and mosquito control. PMID:9092389

  15. Data on the phosphorylation of p38MAPK and JNK induced by chlorpyrifos in Drosophila melanogaster.

    PubMed

    Batista, J E S; Sousa, L R; Martins, I K; Rodrigues, N R; Posser, T; Franco, J L

    2016-12-01

    Exposure to organophosphate compounds, such as chlorpyrifos, has been linked to disturbances on cell signaling pathways. Mitogen activated protein kinases (MAPK) are a family of protein kinases involved in a range of cellular processes, including stress response, apoptosis and survival. Therefore, changes in the activation state of these kinases may characterize key mechanisms of toxicity elicited by xenobiotics. Here we report data on the phosphorylation of p38MAPK and JNK, members of the MAPK family, in Drosophila melanogaster exposed to chlorpyrifos, as characterized by western blotting assays. PMID:27626050

  16. Chlorpyrifos-induced biomarkers in Japanese medaka (Oryzias latipes).

    PubMed

    Jeon, Hwang-Ju; Lee, Yong-Ho; Mo, Hyoung-ho; Kim, Myoung-Jin; Al-Wabel, Mohammad I; Kim, Yongeun; Cho, Kijong; Kim, Tae-Wan; Ok, Yong Sik; Lee, Sung-Eun

    2016-01-01

    Chlorpyrifos (CHL) is an organophosphate compound that is widely used as an insecticide. Due to its repeated use and high environmental residual property, CHL is frequently passed into aquatic environments by runoff. Consequently, there may be an adverse effect on aquatic vertebrate animals, including fish. Therefore, in this study, we assessed how CHL affected Japanese medaka (Oryzias latipes). The acute toxicity of CHL in adult fish after 96 h of exposure was determined to be 212.50, 266.79, and 412.28 μg L(-1) (LC25, LC50, and LC95, respectively). Acetylcholinesterase (AChE), glutathione S-transferase (GST), and carboxylesterase (CE) activities were obtained from the livers of dead or surviving fish, and the results showed 4.8-fold lower, 4.5-fold higher, and 18.6-fold lower activities for the AChE, GST, and CE, respectively, for 64-h exposure at a concentration of 400 μg L(-1) of CHL. In the embryo toxicity test, curved spines were observed in embryos that were exposed to CHL for 48 h in a concentration-dependent manner. With identification of biomarkers for CHL in the fish, two protein peaks, 5550.86 and 5639.79 m/z, were found to be upregulated. These two proteins can be used as protein biomarkers for CHL contamination in aquatic systems. A phosphatidyl choline with an m/z ratio of 556.32 dramatically decreased after CHL exposure in the fish; thus, it may be considered as a lipid biomarker for CHL. It is assumed as the first report to identify a phospholipid biomarker using a lipidomics approach in fish toxicology. Taken together, these results demonstrated the adverse effects of CHL on Japanese medaka and reveal several candidate biomarkers that can be used as diagnostic tools for determining CHL.

  17. Persistent cholinergic presynaptic deficits after neonatal chlorpyrifos exposure.

    PubMed

    Slotkin, T A; Cousins, M M; Tate, C A; Seidler, F J

    2001-06-01

    The commonly-used organophosphate insecticide, chlorpyrifos (CPF), impairs brain cell development, axonogenesis and synaptogenesis. In the current study, we administered CPF to neonatal rats on postnatal (PN) days 1-4 (1 mg/kg) or PN11-14 (5 mg/kg), treatments that were devoid of overt toxicity. We then examined two cholinergic synaptic markers, choline acetyltransferase activity (ChAT) and [3H]hemicholinium-3 binding (HC-3) in the hippocampus, midbrain, striatum, brainstem and cerebral cortex in the juvenile (PN30) and young adult (PN60). Across all brain regions, CPF exposure evoked significant reductions in both markers, with larger effects on HC-3 binding, which is responsive to neuronal impulse activity, than on ChAT, a constitutive marker. Superimposed on the deficits, there were gender-selective effects and distinct regional disparities in the critical exposure period for vulnerability. In the hippocampus, either the early or late treatment regimen evoked decreases in ChAT but the early regimen elicited a much larger decrease in HC-3; effects persisted into adulthood. In the midbrain, CPF administration on PN1-4 elicited deficits similar to those seen in the hippocampus; however, exposure on PN11-14 elicited changes preferentially in females. Gender selectivity was also apparent in the striatum, in this case reflecting deficits in females after CPF treatment on PN1-4. In contrast, the effects of CPF on the brainstem were relatively more robust in males; effects in the cerebral cortex were less notable than in other regions. These results indicate that neonatal CPF exposure produces widespread deficiencies in cholinergic synaptic function that persist into adulthood. The effects are likely to contribute to gender-selective alterations in behavioral performance that persist or emerge long after the termination of exposure and well after the restoration of cholinesterase activity.

  18. Behavioral thermoregulatory response to chlorpyrifos in the rat.

    PubMed

    Gordon, C J

    1997-12-31

    Chlorpyrifos (CHP) is a heavily used organophosphorous-based insecticide that elicits thermoregulatory dysfunction in the rat characterized by an initial period of hypothermia followed by a delayed hyperthermia lasting 24-72 h after exposure. The purpose of the present study was to determine (1) if the delayed hyperthermia is linked to CHP-induced hypothermia and (2) if the hypothermia and delayed hyperthermia are regulated by the CNS thermoregulatory centers. Core temperature (Tc) and motor activity (MA) of female Long-Evans rats were monitored via radiotelemetry. Rats housed in a temperature gradient were administered the control vehicle or CHP (25 mg/kg (p.o.)) while Tc, MA and ambient temperature (Ta) preferred by rats in the gradient (i.e. selected Ta) were recorded. There was an initial reduction in Tc concomitant with a decrease in selected Taa A gradual recovery in Tc occurred during the first night along with a preference for warmer Ta's and depressed MA. The day after CHP there was an elevation in Tc but no change in selected Ta, suggesting that the delayed rise in Tc was regulated. In another experiment, the hypothermic effects of CHP (25 mg/kg (p.o.)) were blocked by raising Ta from 22 to 31 degrees C immediately after CHP administration. Non-heated rats administered CHP underwent a marked period of hypothermia followed by an elevation in diurnal Tc for 2 days. Heated rats showed no hypothermic response but did undergo a hyperthermic response 48 h after CHP. MA was reduced during the first night after CHP in both non-heated and heated groups. Overall, the CHP-induced hyperthermia is not dependent on the development of hypothermia. Behavioral thermoregulatory observations suggest that both hypothermia and hyperthermia are regulated by CNS thermoregulatory centers. PMID:9482118

  19. Toxicity of chlorpyrifos and chlorpyrifos oxon in a transgenic mouse model of the human paraoxonase (PON1) Q192R polymorphism

    SciTech Connect

    Cole, Toby B.; Walter, Betsy J.; Shih, Diana M.; Tward, Aaron D.; Lusis, Aldons J.; Timchalk, Chuck; Richter, Rebecca J.; Costa, Lucio G.; Furlong, Clement E.

    2005-08-01

    The Q192R polymorphism of paraoxonase (PON1) has been shown to affect hydrolysis of organophosphorus compounds. The Q192 and R192 alloforms exhibit equivalent catalytic efficiencies of hydrolysis for diazoxon, the oxon form of the pesticide (DZ). However, the R192 alloform has a higher catalytic efficiency of hydrolysis than does the Q192 alloform for chlorpyrifos oxon (CPO), the oxon form of the pesticide chlorpyrifos (CPS). The current study examined the relevance of these observations for in-vivo exposures to chlorpyrifos and chlorpyrifos oxon. Methods Using a transgenic mouse model we examined the relevance of the Q192R polymorphism for exposure to CPS and CPO in vivo. Transgenic mice were generated that expressed either human PON1Q192 or PON1R192 at equivalent levels, in the absence of endogenous mouse PON1. Dose-response and time course experiments were performed on adult mice exposed dermally to CPS or CPO. Morbidity and acetylcholinesterase (AChE) activity in the brain and diaphragm were determined in the first 24 h following exposure. Results Mice expressing PON1Q192 were significantly more sensitive to CPO, and to a lesser extent CPS, than were mice expressing PON1R192. The time course of inhibition following exposure to 1.2 mg/kg CPO revealed maximum inhibition of brain AChE at 6?12 h, with PON1R192, PON1Q192, and PON1? /? mice exhibiting 40, 70 and 85% inhibition, respectively, relative to control mice. The effect of PON1 removal on the dose?response curve for CPS exposure was remarkably consistent with a PBPK/PD model of CPS exposure. Conclusion These results indicate that individuals expressing only the PON1Q192 allele would be more sensitive to the adverse effects of CPO or CPS exposure, especially if they are expressing a low level of plasma PON1Q192.

  20. Short-term effects of chlorpyrifos and other pesticides on earthworm numbers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chlorpyrifos is generally used on grasses grown for seed to control billbugs (Sphenophorus venatus confluens) and cutworms (various species), and on other crops for crane fly larvae (Tipula sp.), garden symphyllans (Scutigerella immaculate), and wireworms (Agriotes sp.). The indirect impact of cont...

  1. Specific surface area effect on adsorption of chlorpyrifos and TCP by soils and modeling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The adsorption of chlorpyrifos and TCP (3,5,6, trichloro-2-pyridinol) was determined in four soils (Mollisol, Inceptisol, Entisol, Alfisol) having different specific surface areas (19–84 m2/g) but rather similar organic matter content (2.4–3.5%). Adsorption isotherms were derived from batch equilibr...

  2. DOES THE DEVELOPMENTAL NEUROTOXICITY OF CHLORPYRIFOS INVOLVE GLIAL TARGETS? (U915722)

    EPA Science Inventory

    The widespread use of chlorpyrifos (CPF) has raised major concerns about its potential to cause fetal or neonatal neurobehavioral damage, even at doses that do not evoke acute toxicity. CPF has been shown to inhibit replication of brain cells, to elicit alterations in neurotro...

  3. Alterations in social behavior of Japanese medaka (Oryzias latipes) in response to sublethal chlorpyrifos exposure.

    PubMed

    Khalil, Fatma; Kang, Ik Joon; Undap, Suzanne; Tasmin, Rumana; Qiu, Xuchun; Shimasaki, Yohei; Oshima, Yuji

    2013-06-01

    The behavioral and biochemical responses of Japanese medaka (Oryzias latipes) to acute and subacute (sublethal) levels of chlorpyrifos were studied. In the acute exposure test, medaka were exposed to 0.018, 0.055, 0.166, or 0.500 mg L(-1) chlorpyrifos for 4 d. As a result, fish showed hypoactivity compared to the control (at 0.018, 0.055, and 0.166 mg L(-1), swimming speeds were 55.6%, 39.0%, and 27.3% those of the control), Brain acetylcholinesterase activity and swimming speed were significantly correlated. In the subacute toxicity test, medaka were exposed to 0.012 mg L(-1) chlorpyrifos (10% of LC(50)) for 8 d. On day 4, there were no significant differences in behavioral and biochemical endpoints in exposed fish as compared to the control. On day 8, exposed fish became hyperactive, and the swimming speed of the social group increased to 2 times that of the control, whereas acetylcholinesterase activity was decreased to 68% that of the control. In addition, fish exhibited significant alterations in social behavior (schooling duration increased to 2.6 times and solitary duration decreased to 28% that of the control). Our findings clearly demonstrate a subacute effect of chlorpyrifos on the social behavior of medaka, which may pose a risk at population level because of the disturbance of social behavior. In addition, the recorded behavioral alterations may provide a useful tool for assessing the toxicity of organophosphorous pesticides to aquatic organisms.

  4. Comparative and combined acute toxicity of butachlor, imidacloprid and chlorpyrifos on earthworm, Eisenia fetida.

    PubMed

    Chen, Chen; Wang, Yanhua; Zhao, Xueping; Wang, Qiang; Qian, Yongzhong

    2014-04-01

    Various pesticides have become widespread contaminants of soils due to their large applications in agriculture and homes. An earthworm assay was used to assess the acute toxicity of butachlor, imidacloprid and chlorpyrifos with different modes of action. Ecotoxicities of these pesticides were compared for earthworm Eisenia fetida separately and in combination in artificial soil and contact filter paper tests. Imidacloprid was the most toxic for E. fetida with LC₅₀ (lethal concentration 50) values three orders magnitude lower than that of butachlor and chlorpyrifos in both tests. The toxicity of the mixtures was compared to that predicted by the concentration addition (CA) model. According to the CA model, the observed toxicities of all binary mixtures were less than additive. However, for all the mixtures in 14 d artificial soil test, and mixtures of butachlor plus chlorpyrifos and imidacloprid plus chlorpyrifos in 48 h contact filter paper test, the difference in toxicity was less than 30%, hence it was concluded that the mixtures conformed to CA. The combined effects of the pesticides in contact filter paper tests were not consistent with the results in artificial soil toxicity tests, which may be associated with the interaction of soil salts with the pesticides. The CA model provides estimates of mixture toxicity that did not markedly underestimate the measured toxicity, and therefore the CA model is the most suitable to use in ecological risk assessments of the pesticides.

  5. The effects of chlorpyrifos on cholinesterase activity and foraging behavior in the dragonfly, Anax junius (Odonata)

    USGS Publications Warehouse

    Brewer, S.K.; Atchison, G.J.

    1999-01-01

    We examined head capsule cholinesterase (ChE) and foraging behavior in nymphs of the dragonfly, Anax junius, exposed for 24 h to 0.2, 0.6 and 1.0 ??g l-1 of the organophosphorus (OP) insecticide, chlorpyrifos [O,O-diethyl O-(3,5,6-trichloro-2-pyridyl) phosphorothioate]. The invertebrate community is an important component of the structure and function of wetland ecosystems, yet the potential effects of insecticides on wetland ecosystems are largely unknown. Our objectives were to determine if exposure to environmentally realistic concentrations of chlorpyrifos affected foraging behavior and ChE activity in head capsules of dragonfly nymphs. Nymphs were exposed to different concentrations of chlorpyrifos and different prey densities in a factorial design. ChE activities and foraging behaviors of treated nymphs were not statistically different (p ??? 0.05) from control groups. Prey density effects exerted a greater effect on dragonfly foraging than toxicant exposures. Nymphs offered higher prey densities exhibited more foraging behaviors but also missed their prey more often. High variability in ChE activities within the control group and across treated groups precluded determination of relationships between ChE and foraging behaviors. It appears that A. junius is relatively tolerant of chlorpyrifos, although the concentrations we tested have been shown in other work to adversely affect the prey base; therefore the introduction of this insecticide may have indirect adverse affects on top invertebrate predators such as Odonata.

  6. Adsorption of chlorpyrifos, penconazole and metalaxyl from aqueous solution by modified clays.

    PubMed

    Suciu, Nicoleta A; Capri, Ettore

    2009-08-01

    Sorption of three pesticides (chlorpyrifos, metalaxyl and penconazole) has been measured on a commercial clay montmorillonite and on the same mineral modified with either of two cationic-surfactant micelles. Both micelle-clay complexes, commercial names Cloisite 20A and Cloisite 30B, showed a good capacity to sorb all three pesticides from water, whereas their sorption on the natural montmorillonite was not described by an isotherm. Modelling sorption on both micelle-clay complexes showed that the Freundlich sorption constant (K(F)) was higher for chlorpyrifos on Cloisite 20A (K(F) = 7.76) than on Cloisite 30B (K(F) = 5.91), whereas the sorption of metalaxyl was stronger on Cloisite 30B (K(F) = 1.07) than on Cloisite 20A (K(F) = 0.57). Moreover the micelle-clay complex Cloisite 20A also showed a good affinity for penconazole, the maximum quantity adsorbed (q(m)) of 6.33 mg g(-1) being 45% more than that on Cloisite 30B. Single-batch adsorption of each pesticide onto both micelle-clay complexes was studied using the Freundlich isotherm for chlorpyrifos and metalaxyl and the Langmuir isotherm for penconazole. The Cloisite 20A micelle-clay complex was predicted to require 23% less adsorbent to treat certain volumes of wastewater containing 30 mg L(-1) chlorpyrifos, 43% more to treat metalaxyl similarly and 57% less to treat penconazole compared with Cloisite 30B. PMID:20183058

  7. AGE-RELATED EFFECTS OF CHLORPYRIFOS ON ACETYLCHOLINE RELEASE IN RAT BRAIN. (R825811)

    EPA Science Inventory

    Chlorpyrifos (CPF) is an organophosphorus insecticide that elicits toxicity through inhibition of acetylcholinesterase (AChE). Young animals are markedly more sensitive than adults to the acute toxicity of CPF. We evaluated acetylcholine (ACh) release and its muscarinic recept...

  8. PRENATAL EXPOSURE TO CHLORPYRIFOS ALTERS NEUROTROPHIN IMMUNOREACTIVITY AND APOPTOSIS IN RAT BRAIN.

    EPA Science Inventory

    In the present study, the effects of the organophosphate pesticide chlorpyrifos [CPF; O,O'diethyl O-3,5,6-trichloro-2-pyridyl) phosphorothionate] on the regional distribution of three neurotrophic factors and on levels of apoptosis in gestational rat brain were characterized. P...

  9. Inhibition of acetylcholinesterase in guppies (Poecilia reticulata) by chlorpyrifos at sublethal concentrations: Methodological aspects

    SciTech Connect

    van der Wel, H.; Welling, W.

    1989-04-01

    Acetylcholinesterase activity is a potential biochemical indicator of toxic stress in fish and a sensitive parameter for testing water for the presence of organophosphates. A number of methodological aspects regarding the determination of the in vivo effect of chlorpyrifos on acetylcholinesterase in guppies have been investigated. It was found that with acetylthiocholine as a substrate, the contribution of pseudocholinesterase to the total cholinesterase activity can be neglected. Protection of acetylcholinesterase of guppies exposed to chlorpyrifos from additional, artifactual in vitro enzyme inhibition during homogenization is necessary. Very low concentrations of acetone in the exposure medium, resulting from dilution of the stock solution of chlorpyrifos in acetone, can result in large decreases in the oxygen content of this medium. This may affect the uptake rate of the toxic compound and, thereby, cholinesterase inhibition. Very low, sublethal concentrations of chlorpyrifos result in high inhibition levels of acetylcholinesterase (80-90%) in guppies within 2 weeks of continuous exposure. Recovery of the enzyme activity occurs after the exposed animals are kept in clean medium for 4 days, but the rate of recovery is considerably lower than the rate of inhibition.

  10. THERMOREGULATION IN THE RAT DURING CHRONIC, DIETARY EXPOSURE TO CHLORPYRIFOS, AN ORGANOPHOSPHATE INSECTICIDE.

    EPA Science Inventory

    Administration of chlorpyrifos (CHP) at a dose of 25 to 80 mg/kg (p.o.) To rats results in hypothermia followed by a fever lasting for several days. To understand if chronic, low level exposure to CHP affects thermoregulation in a comparable manner to acute administration, male L...

  11. CHANGES IN THE RAT EEG SPECTRA AND CORE TEMPERATURE AFTER EXPOSURE TO DIFFERENT DOSES OF CHLORPYRIFOS.

    EPA Science Inventory

    Our previous study showed that single exposure to 25 mg/kg (p.o.) of organophsphate pesticide chlorpyrifos (CHP) led to significant alterations in all EEG frequency bands within 0.1-50 Hz range, reduction in core temperature (Tc) and motor activity (MA). The alterations in EEG pe...

  12. NEUROBEHAVIORAL EFFECTS OF CHRONIC DIETARY AND REPEATED HIGH-LEVEL SPIKE EXPOSURE TO CHLORPYRIFOS IN RATS.

    EPA Science Inventory

    This study aimed to model long-term subtoxic human exposure to an organophosphorus pesticide, chlorpyrifos, and to examine the influence of that exposure on the response to intermittent high-dose acute challenges. Adult Long-Evans male rats were maintained at 350g body weight by...

  13. Chlorpyrifos-treated crops in the vicinity of surface water contamination in the San Joaquin Valley, California, USA.

    PubMed

    Starner, Keith; Goh, Kean S

    2013-09-01

    Due to frequent contamination of streams in the San Joaquin Valley, California, USA, with the insecticide chlorpyrifos, researchers are working to identify crop-specific management practices that will reduce the offsite movement of this compound into surface waters. To guide this effort, crops treated with chlorpyrifos in the vicinity of contaminated streams were identified; walnut, alfalfa, and almond were the primary crops identified. Use was higher on walnut and almond, but due to irrigation practices offsite movement in surface runoff may be more likely from alfalfa. Based on these findings, development of management practices to reduce off-site movement of chlorpyrifos in irrigation runoff from treated alfalfa fields is recommended.

  14. Dietary exposure to chlorpyrifos alters core temperature in the rat.

    PubMed

    Gordon, Christopher J; Padnos, Beth K

    2002-08-15

    Administration of the organophosphate pesticide chlorpyrifos (CHP) to the male rat at a dose of 25-80 mg/kg (p.o.) results in hypothermia followed by a delayed fever lasting for several days. These are high doses of CHP that cause marked cholinergic stimulation. It is important to understand if chronic exposure to CHP would evoke changes in thermoregulation that are comparable to the acute administration. Male rats of the Long-Evans strain were subjected to dietary treatment of 0, 1, or 5 mg/(kg day) CHP for 6 months. A limited amount of food was given per day to maintain body weight at 350 g. The constant body weight allowed for the regulation of a consistent dosage of CHP per kg body weight throughout the feeding period. Core temperature (T(a)) and motor activity (MA) were monitored by radio telemetric transmitters implanted in the abdominal cavity. After 5 months of treatment, T(c) and MA were monitored in undisturbed animals for 96 h. CHP at 5 mg/(kg day) led to a slight elevation in T(c) without affecting MA. The rats were then administered a challenge dose of CHP (30 mg/kg, p.o.) while T(c) and MA were monitored. Rats fed the 1 and 5 mg/kg CHP diets showed a significantly greater hypothermic response and reduction in MA following CHP challenge compared to controls. The restricted feeding schedule resulted in marked changes in the pattern of the circadian rhythm. Therefore, in another study, rats were treated ad libitum for 17 days with a CHP diet that resulted in a dosage of 7 mg CHP/(mg day). There was a significant increase in T(c) during the daytime but not during the night throughout most of the treatment period. Overall, chronic CHP was associated with a slight but significant elevation in T(c) and greater hypothermic response to a CHP challenge. This latter finding was unexpected and suggests that chronic exposure to CHP sensitizes the rat's thermoregulatory response to acute CHP exposure. PMID:12135625

  15. Prenatal nicotine changes the response to postnatal chlorpyrifos: Interactions targeting serotonergic synaptic function and cognition.

    PubMed

    Slotkin, Theodore A; Skavicus, Samantha; Levin, Edward D; Seidler, Frederic J

    2015-02-01

    Nicotine and chlorpyrifos are developmental neurotoxicants that target serotonin systems. We examined whether prenatal nicotine exposure alters the subsequent response to chlorpyrifos given postnatally. Pregnant rats received nicotine throughout gestation at 3mg/kg/day, a regimen designed to achieve plasma levels seen in smokers; chlorpyrifos was given to pups on postnatal days (PN) 1-4 at 1mg/kg, just above the detection threshold for brain cholinesterase inhibition. We assessed long-term effects from adolescence (PN30) through full adulthood (PN150), measuring the expression of serotonin receptors and serotonin turnover (index of presynaptic impulse activity) in cerebrocortical brain regions encompassing the projections that are known targets for nicotine and chlorpyrifos. Nicotine or chlorpyrifos individually increased the expression of serotonin receptors, with greater effects on males than on females and with distinct temporal and regional patterns indicative of adaptive synaptic changes rather than simply an extension of initial injury. This interpretation was confirmed by our finding an increase in serotonin turnover, connoting presynaptic serotonergic hyperactivity. Animals receiving the combined treatment showed a reduction in these adaptive effects on receptor binding and turnover relative to the individual agents, or even an effect in the opposite direction; further, normal sex differences in serotonin receptor concentrations were dissipated or reversed, an effect that was confirmed by behavioral evaluations in the Novel Objection Recognition Test. In addition to the known liabilities associated with maternal smoking during pregnancy, our results point to additional costs in the form of heightened vulnerability to neurotoxic chemicals encountered later in life. PMID:25592617

  16. Dissipation and distribution of chlorpyrifos in selected vegetables through foliage and root uptake.

    PubMed

    Ge, Jing; Lu, Mengxiao; Wang, Donglan; Zhang, Zhiyong; Liu, Xianjin; Yu, Xiangyang

    2016-02-01

    Dissipation, distribution and uptake pathways of chlorpyrifos were investigated in pakchoi (Brassica chinensis L.) and lettuce (Lactuca sativa) with foliage treatments under a greenhouse trial and root treatments under a hydroponic experiment. The dissipation trends were similar for chlorpyrifos in pakchoi and lettuce with different treatments. More than 94% of chlorpyrifos was degraded in the samples for both of the vegetables 21 days after the foliage treatments. For the root treatment, the dissipation rate of chlorpyrifos in pakchoi and lettuce at the low concentration was greater than 93%, however, for the high concentrations, the dissipation rates were all under 90%. Both shoots and roots of the vegetables were able to absorb chlorpyrifos from the environment and distribute it inside the plants. Root concentration factor (RCF) values at different concentrations with the hydroponic experiment ranged from 5 to 39 for pakchoi, and from 14 to 35 for lettuce. The translocation factor (TF) representing the capability of the vegetables to translocate contaminants was significantly different for pakchoi and lettuce with foliage and root treatments. The values of TF with foliage treatments ranged from 0.003 to 0.22 for pakchoi, and from 0.032 to 1.63 for lettuce. The values of TF with root treatments ranged from 0.01 to 0.17 for pakchoi, and from 0.003 to 0.23 for lettuce. Significant difference of TF was found between pakchoi and lettuce with foliage treatments, and at high concentrations (10 and 50 mg L(-1)) with root treatments as well. However, there was no significant difference of TF between pakchoi and lettuce at 1 mg L(-1) with root treatment.

  17. Concentration-dependent interactions of the organophosphates chlorpyrifos oxon and methyl paraoxon with human recombinant acetylcholinesterase

    SciTech Connect

    Kaushik, R.; Rosenfeld, Clint A.; Sultatos, L.G. . E-mail: sultatle@umdnj.edu

    2007-06-01

    For many decades it has been thought that oxygen analogs (oxons) of organophosphorus insecticides phosphorylate the catalytic site of acetylcholinesterase by a mechanism that follows simple Michaelis-Menten kinetics. More recently, the interactions of at least some oxons have been shown to be far more complex and likely involve binding of oxons to a second site on acetylcholinesterase that modulates the inhibitory capacity of other oxon molecules at the catalytic site. The current study has investigated the interactions of chlorpyrifos oxon and methyl paraoxon with human recombinant acetylcholinesterase. Both chlorpyrifos oxon and methyl paraoxon were found to have k {sub i}'s that change as a function of oxon concentration. Furthermore, 10 nM chlorpyrifos oxon resulted in a transient increase in acetylthiocholine hydrolysis, followed by inhibition. Moreover, in the presence of 100 nM chlorpyrifos oxon, acetylthiocholine was found to influence both the K {sub d} (binding affinity) and k {sub 2} (phosphorylation constant) of this oxon. Collectively, these results demonstrate that the interactions of chlorpyrifos oxon and methyl paraoxon with acetylcholinesterase cannot be described by simple Michaelis-Menten kinetics but instead support the hypothesis that these oxons bind to a secondary site on acetylcholinesterase, leading to activation/inhibition of the catalytic site, depending on the nature of the substrate and inhibitor. Additionally, these data raise questions regarding the adequacy of estimating risk of low levels of insecticide exposure from direct extrapolation of insecticide dose-response curves since the capacity of individual oxon molecules at low oxon levels could be greater than individual oxon molecules in vivo associated with the dose-response curve.

  18. Dissipation and distribution of chlorpyrifos in selected vegetables through foliage and root uptake.

    PubMed

    Ge, Jing; Lu, Mengxiao; Wang, Donglan; Zhang, Zhiyong; Liu, Xianjin; Yu, Xiangyang

    2016-02-01

    Dissipation, distribution and uptake pathways of chlorpyrifos were investigated in pakchoi (Brassica chinensis L.) and lettuce (Lactuca sativa) with foliage treatments under a greenhouse trial and root treatments under a hydroponic experiment. The dissipation trends were similar for chlorpyrifos in pakchoi and lettuce with different treatments. More than 94% of chlorpyrifos was degraded in the samples for both of the vegetables 21 days after the foliage treatments. For the root treatment, the dissipation rate of chlorpyrifos in pakchoi and lettuce at the low concentration was greater than 93%, however, for the high concentrations, the dissipation rates were all under 90%. Both shoots and roots of the vegetables were able to absorb chlorpyrifos from the environment and distribute it inside the plants. Root concentration factor (RCF) values at different concentrations with the hydroponic experiment ranged from 5 to 39 for pakchoi, and from 14 to 35 for lettuce. The translocation factor (TF) representing the capability of the vegetables to translocate contaminants was significantly different for pakchoi and lettuce with foliage and root treatments. The values of TF with foliage treatments ranged from 0.003 to 0.22 for pakchoi, and from 0.032 to 1.63 for lettuce. The values of TF with root treatments ranged from 0.01 to 0.17 for pakchoi, and from 0.003 to 0.23 for lettuce. Significant difference of TF was found between pakchoi and lettuce with foliage treatments, and at high concentrations (10 and 50 mg L(-1)) with root treatments as well. However, there was no significant difference of TF between pakchoi and lettuce at 1 mg L(-1) with root treatment. PMID:26363321

  19. Prenatal Dexamethasone Augments the Neurobehavioral Teratology of Chlorpyrifos: Significance for Maternal Stress and Preterm Labor

    PubMed Central

    Levin, Edward D.; Cauley, Marty; Johnson, Joshua E.; Cooper, Ellen M.; Stapleton, Heather M.; Ferguson, P. Lee; Seidler, Frederic J.; Slotkin, Theodore A.

    2014-01-01

    Glucocorticoids are the consensus treatment given in preterm labor and are also elevated by maternal stress; organophosphate exposures are virtually ubiquitous, so human developmental coexposures to these two agents are common. This study explores how prenatal dexamethasone exposure modifies the neurobehavioral teratology of chlorpyrifos, one of the most widely used organophosphates. We administered dexamethasone to pregnant rats on gestational days 17-19 at a standard therapeutic dose (0.2 mg/kg); offspring were then given chlorpyrifos on postnatal days 1-4, at a dose (1 mg/kg) that produces barely-detectable (<10%) inhibition of brain cholinesterase activity. Dexamethasone did not alter brain chlorpyrifos concentrations, nor did either agent alone or in combination affect brain thyroxine levels. Assessments were carried out from adolescence through adulthood encompassing T-maze alternation, Figure-8 maze (locomotor activity, habituation), novelty-suppressed feeding and novel object recognition tests. For behaviors where chlorpyrifos or dexamethasone individually had small effects, the dual exposure produced larger, significant effects that reflected additivity (locomotor activity, novelty-suppressed feeding, novel object recognition). Where the individual effects were in opposite directions or were restricted to only one agent, we found enhancement of chlorpyrifos’ effects by prenatal dexamethasone (habituation). Finally, for behaviors where controls displayed a normal sex difference in performance, the combined treatment either eliminated or reversed the difference (locomotor activity, novel object recognition). Combined exposure to dexamethasone and chlorpyrifos results in a worsened neurobehavioral outcome, providing a proof-of-principle that prenatal glucocorticoids can create a subpopulation with enhanced vulnerability to environmental toxicants. PMID:24177596

  20. Acetylcholinesterase inhibition in the threeridge mussel (Amblema plicata) by chlorpyrifos: implications for biomonitoring

    USGS Publications Warehouse

    Doran, W.J.; Cope, W.G.; Rada, R.G.; Sandheinrich, M.B.

    2001-01-01

    The effects of chlorpyrifos, an organophosphorus insecticide, were examined on the activity of the nervous system enzyme acetylcholinesterase (AChE) in the threeridge mussel Amblema plicata in a 24-day laboratory test. Thirty-six mussels in each of seven treatments (18 mussels per duplicate) were exposed to chlorpyrifos (0.1, 0.2, 0.3, 0.6, and 1.2 mg/L), a solvent (acetone), and a solvent-free (well water) control for 12, 24, or 96 h. The activity of AChE was measured in the anterior adductor muscle of eight mussels from each treatment after exposure. To assess potential latent effects, six mussels from each treatment were removed after 24 h of exposure and transferred to untreated water for a 21-day holding period; AChE activity was measured on three mussels from each treatment at 7 and 21 days of the holding period. The activity of AChE in chlorpyrifos-exposed mussels did not differ from controls after 12 or 24 h of exposure (t- test, P>0.05), but was significantly less than controls after 96 h (t- test, P=0.01). AChE activity did not vary among mussels at 24 h of exposure (i.e., Day 0 of holding period) and those at Day 7 and Day 21 of the holding period. Overall changes in AChE activity of mussels during the test were unrelated to individual chlorpyrifos concentrations and exposure times (repeated measure ANOVA; (P=0.06). A power analysis revealed that the sample size must be increased from 2 to 5 replicates (8 to 20 mussels per time interval and test concentration) to increase the probability of detecting significant differences in AChE activity. This calculated increase in sample size has potential implications for future biomonitoring studies with chlorpyrifos and unionid mussels.

  1. CHRONIC DIETARY EXPOSURE WITH INTERMITTENT SPIKE DOSES OF CHLORPYRIFOS FAILS TO ALTER BRAINSTEM AUDITORY EVOKED RESPONSE (BAERS) IN RATS.

    EPA Science Inventory

    Human exposure to pesticides is often characterized by chronic low level exposure with intermittent spiked higher exposures. Cholinergic transmission is involved in auditory structures in the periphery and the brainstem and is altered following chlorpyrifos exposure. This study e...

  2. Alterations in the fatty acid profile, antioxidant enzymes and protein pattern of Biomphalaria alexandrina snails exposed to the pesticides diazinon and profenfos.

    PubMed

    Bakry, Fayez A; El-Hommossany, Karem; Abd El-Atti, Mahmoud; Ismail, Somaya M

    2016-04-01

    The use of pesticides is widespread in agricultural activities. These pesticides may contaminate the irrigation and drainage systems during agriculture activities and pests' control and then negatively affect the biotic and a biotic component of the polluted water courses. The present study aimed to evaluate the effect of the pesticides diazinon and profenfos on some biological activities of Biomphalaria alexandrina snails such as fatty acid profile, some antioxidant enzymes (thioredoxin reductase (TrxR), sorbitol dehydrogenase (SDH), superoxide dismutase (SOD), catalase (CAT) as well as glutathione reductase (GR) and lipid peroxidation (LP)) and protein patterns in snails' tissues exposed for 4 weeks to LC10 of diazinon and profenfos. The results showed that the two pesticides caused considerable reduction in survival rates and egg production of treated snails. Identification of fatty acid composition in snail tissues treated with diazinon and profenfos pesticides was carried out using gas-liquid chromatography (GLC). The results declared alteration in fatty acid profile, fluctuation in percentage of long chain and short chain fatty acid contributions either saturated or unsaturated ones, and a decrease in total lipid content in tissues of snails treated with these pesticides. The data demonstrate that there was a significant inhibition in the activities of tissues SOD, CAT, glutathione reductase (GR), TrxR, and SDH in tissues of treated snails, while a significant elevation was detected in LP as compared to the normal control. On the other hand, the electrophoretic pattern of total protein showed differences in number and molecular weights of protein bands due to the treatment of snails. It was concluded that the residues of diazinon and profenfos pesticides in aquatic environments have toxic effects onB. alexandrina snails.

  3. Sensitivity of brain cholinesterase activity to diazinon (BASUDIN 50EC) and fenobucarb (BASSA 50EC) insecticides in the air-breathing fish Channa striata (Bloch, 1793).

    PubMed

    Van Cong, Nguyen; Phuong, Nguyen Thanh; Bayley, Mark

    2006-05-01

    With the expansion of agricultural areas within the Mekong River Delta in Vietnam, a concurrent, dramatic increase has occurred in agrochemical usage. To date, little consideration has been given to the negative impacts of this agricultural activity on the aquatic resources of the region. Both acute toxicity and subacute effects on brain cholinesterase (ChE) of two of the most commonly used insecticides, diazinon and fenobucarb, on adult native snakehead (Channa striata) were evaluated in a static, nonrenewable system, the environmental parameters of which, such as dissolved oxygen, water temperature, and pH, fluctuated similarly to field conditions. Four levels of insecticides, from 0.008 to 0.52 mg/L (for diazinon) and from 0.11 to 9.35 mg/L (for fenobucarb), were tested to assess the effects on the brain ChE activity of the snakehead up to 30 and 10 d for diazinon and fenobucarb, respectively. Diazinon was highly toxic to this fish species, with a 96-h median lethal concentration (LC50) of only 0.79 mg/L, and it also caused long-term ChE inhibition, with activity still significantly inhibited by 30% after 30 d for the three highest concentrations. Fenobucarb was less toxic to this species, with a 96-h LC50 of 11.4 mg/L. Fenobucarb caused more rapid ChE inhibition but also rapid recovery. The results of the present study indicate an urgent need to regulate the usage of these pesticides in the Mekong River Delta. PMID:16704077

  4. Inhibition of recombinant human carboxylesterase 1 and 2 and monoacylglycerol lipase by chlorpyrifos oxon, paraoxon and methyl paraoxon

    SciTech Connect

    Crow, J. Allen; Bittles, Victoria; Herring, Katye L.; Borazjani, Abdolsamad; Potter, Philip M.; Ross, Matthew K.

    2012-01-01

    Oxons are the bioactivated metabolites of organophosphorus insecticides formed via cytochrome P450 monooxygenase-catalyzed desulfuration of the parent compound. Oxons react covalently with the active site serine residue of serine hydrolases, thereby inactivating the enzyme. A number of serine hydrolases other than acetylcholinesterase, the canonical target of oxons, have been reported to react with and be inhibited by oxons. These off-target serine hydrolases include carboxylesterase 1 (CES1), CES2, and monoacylglycerol lipase. Carboxylesterases (CES, EC 3.1.1.1) metabolize a number of xenobiotic and endobiotic compounds containing ester, amide, and thioester bonds and are important in the metabolism of many pharmaceuticals. Monoglyceride lipase (MGL, EC 3.1.1.23) hydrolyzes monoglycerides including the endocannabinoid, 2-arachidonoylglycerol (2-AG). The physiological consequences and toxicity related to the inhibition of off-target serine hydrolases by oxons due to chronic, low level environmental exposures are poorly understood. Here, we determined the potency of inhibition (IC{sub 50} values; 15 min preincubation, enzyme and inhibitor) of recombinant CES1, CES2, and MGL by chlorpyrifos oxon, paraoxon and methyl paraoxon. The order of potency for these three oxons with CES1, CES2, and MGL was chlorpyrifos oxon > paraoxon > methyl paraoxon, although the difference in potency for chlorpyrifos oxon with CES1 and CES2 did not reach statistical significance. We also determined the bimolecular rate constants (k{sub inact}/K{sub I}) for the covalent reaction of chlorpyrifos oxon, paraoxon and methyl paraoxon with CES1 and CES2. Consistent with the results for the IC{sub 50} values, the order of reactivity for each of the three oxons with CES1 and CES2 was chlorpyrifos oxon > paraoxon > methyl paraoxon. The bimolecular rate constant for the reaction of chlorpyrifos oxon with MGL was also determined and was less than the values determined for chlorpyrifos oxon with CES1

  5. Persistence and dissipation of chlorpyrifos in Brassica chinensis, lettuce, celery, asparagus lettuce, eggplant, and pepper in a greenhouse.

    PubMed

    Lu, Meng-Xiao; Jiang, Wayne W; Wang, Jia-Lei; Jian, Qiu; Shen, Yan; Liu, Xian-Jin; Yu, Xiang-Yang

    2014-01-01

    The residue behavior of chlorpyrifos, which is one of the extensively used insecticides all around the world, in six vegetable crops was assessed under greenhouse conditions. Each of the vegetables was subjected to a foliar treatment with chlorpyrifos. Two analytical methods were developed using gas chromatography equipped with a micro-ECD detector (LOQ = 0.05 mg kg(-1)) and liquid chromatography with a tandem mass spectrometry (LOQ = 0.01 mg kg(-1)). The initial foliar deposited concentration of chlorpyrifos (mg kg(-1)) on the six vegetables followed the increasing order of brassica chinensischlorpyrifos showed differences among the six selected vegetable plants, ranging from 16.5±0.9 mg kg(-1) (brassica chinensis) to 74.0±5.9 mg kg(-1) (pepper plant). At pre-harvest interval 21 days, the chlorpyrifos residues in edible parts of the crops were <0.01 (eggplant fruit), <0.01 (pepper fruit), 0.56 (lettuce), 0.97 (brassica chinensis), 1.47 (asparagus lettuce), and 3.50 mg kg(-1) (celery), respectively. The half-lives of chlorpyrifos were found to be 7.79 (soil), 2.64 (pepper plants), 3.90 (asparagus lettuce), 3.92 (lettuce), 5.81 (brassica chinensis), 3.00 (eggplant plant), and 5.45 days (celery), respectively. The dissipation of chlorpyrifos in soil and the six selected plants was different, indicating that the persistence of chlorpyrifos residues strongly depends upon leaf characteristics of the selected vegetables.

  6. Genotoxicity of chlorpyrifos in freshwater fish Labeo rohita using Alkaline Single-cell Gel Electrophoresis (Comet) assay.

    PubMed

    Ismail, Muhammad; Khan, Qaiser Mahmood; Ali, Rahat; Ali, Tayyaba; Mobeen, Ameena

    2014-10-01

    Chlorpyrifos is a widely used insecticide of organophosphate group, which causes severe toxicological effects in non target aquatic organisms especially in fish. In the present study the genotoxic effects of sublethal concentrations of chlorpyrifos were observed in the erythrocytes and gill cells of Labeo rohita (commonly known as rohu) using the Alkaline Single-Cell Gel Electrophoresis (Comet) assay. Effects of chlorpyrifos on the behavior of the fish were also investigated. The 96 h LC50 value of chlorpyrifos, estimated by Trimmed Spearman-Karber (TSK) in static bioassay, was found to be 442.8 µg/L. On the basis of LC50 value, the fish were exposed to three sublethal concentrations of chlorpyrifos (SL-I ∼221.4 µg/L, SL- II ∼110.7 µg/L and SL-III ∼73.8 µg/L) for 96 h. Blood and gill samples were collected at every 24 h and were subjected to the Comet assay. The observed DNA damage was concentration dependent and time dependent and those levels of DNA damage in between the tested concentrations and times were significantly different (p < 0.01). It was also found that the gill cells are more sensitive to chlorpyrifos, though; it revealed more DNA damage as compared to the erythrocytes of fish. Fish exposed to different concentrations of chlorpyrifos showed different neurotoxic behavioral responses. It was concluded that chlorpyrifos is a genotoxic and neurotoxic insecticide causing DNA damage and neurotoxic effects in Labeo rohita.

  7. Persistence and Dissipation of Chlorpyrifos in Brassica Chinensis, Lettuce, Celery, Asparagus Lettuce, Eggplant, and Pepper in a Greenhouse

    PubMed Central

    Lu, Meng-Xiao; Jiang, Wayne W.; Wang, Jia-Lei; Jian, Qiu; Shen, Yan; Liu, Xian-Jin; Yu, Xiang-Yang

    2014-01-01

    The residue behavior of chlorpyrifos, which is one of the extensively used insecticides all around the world, in six vegetable crops was assessed under greenhouse conditions. Each of the vegetables was subjected to a foliar treatment with chlorpyrifos. Two analytical methods were developed using gas chromatography equipped with a micro-ECD detector (LOQ = 0.05 mg kg−1) and liquid chromatography with a tandem mass spectrometry (LOQ = 0.01 mg kg−1). The initial foliar deposited concentration of chlorpyrifos (mg kg−1) on the six vegetables followed the increasing order of brassica chinensischlorpyrifos showed differences among the six selected vegetable plants, ranging from 16.5±0.9 mg kg−1 (brassica chinensis) to 74.0±5.9 mg kg−1 (pepper plant). At pre-harvest interval 21 days, the chlorpyrifos residues in edible parts of the crops were <0.01 (eggplant fruit), <0.01 (pepper fruit), 0.56 (lettuce), 0.97 (brassica chinensis), 1.47 (asparagus lettuce), and 3.50 mg kg−1 (celery), respectively. The half-lives of chlorpyrifos were found to be 7.79 (soil), 2.64 (pepper plants), 3.90 (asparagus lettuce), 3.92 (lettuce), 5.81 (brassica chinensis), 3.00 (eggplant plant), and 5.45 days (celery), respectively. The dissipation of chlorpyrifos in soil and the six selected plants was different, indicating that the persistence of chlorpyrifos residues strongly depends upon leaf characteristics of the selected vegetables. PMID:24967589

  8. Plasma cholinesterase inhibition in the clay-colored robin (Turdus grayi) exposed to diazinon in maradol papaya crops in Yucatan, Mexico

    USGS Publications Warehouse

    Cobos, V.M.; Mora, M.A.; Escalona, G.

    2006-01-01

    The use of organophosphorous pesticides in agriculture can result in intoxication of birds foraging in sprayed crops. Effects on birds resulting from pesticide intoxication are varied and include behavioral and reproductive effects, including death. One widely used insecticide in Maradol papaya crops is diazinon which has been associated with various incidents of intoxication and death of wild birds. The objective of this study was to evaluate the impact of diazinon application to papaya crops on plasma cholinesterase activity of the clay-colored robin (Turdus grayi). We captured clay-colored robins foraging in a papaya crop the following day after the field had been sprayed with diazinon at a dose of 1.5 kg/ha during March and May, respectively. We took a blood sample from the brachialis vein of the birds captured and measured plasma enzymatic activity. The plasma samples from birds used as controls were taken during the same time period and were analyzed in a similar way. Enzymatic activity of males was greater than that of females (53,52%) and mean cholinesterase inhibition was 49.43%. Cholinesterase inhibition was greater during May than in March probably due to more continuous exposure and ingestion of the insecticide through food and possible absorption through the skin. This degree of enzymatic inhibition is possibly affecting the behavior of the clay-colored robin and could result in death in severe cases.

  9. Differential toxic effects of Carbofuran and Diazinon on time of flight in pigeons (Columba livia): Potential for pesticide effects on migration

    SciTech Connect

    Brasel, Jeffrey M.; Collier, Abby C.; Pritsos, Chris A. . E-mail: pritsos@cabnr.unr.edu

    2007-03-15

    Cholinesterase inhibiting compounds such as carbamates and organophosphate insecticides have been widely used in agriculture since the ban on organochlorines in the 1970s. Carbofuran, a carbamate, and diazinon, an organophosphate, are among the most commonly implicated cholinesterase inhibitors in episodes of accidental avian toxicity and mortality. Despite the apparent effects of these compounds, little work has been done to study effects of low-level, environmentally relevant doses at the population level in migratory bird species. In this study, homing pigeons were used as surrogate species to assess the differences in the effect of incrementally low doses (0.0, 0.25, 0.5, and 1.0 mg/kg) of carbofuran and diazinon on time of flight and determine whether there was a threshold dose of either or both xenobiotics when orally administered at these levels. The results indicate that there is a significant dose-dependent increase in flight time in pigeons dosed with carbofuran while diazinon exposed pigeons showed little effect. More profound effects were noted with carbofuran with pigeons falling off the pace of the flock and a dose for highly significant increase in flight time elucidated between 0.5 and 1.0 mg/kg. The results of the studies validate the homing pigeon as a good subject for comparative studies of cholinesterase inhibitors in birds and the need for further research on repeated low-level exposures on populations of avian species.

  10. Use of Bacillus thuringiensis supernatant from a fermentation process to improve bioremediation of chlorpyrifos in contaminated soils.

    PubMed

    Aceves-Diez, Angel E; Estrada-Castañeda, Kelly J; Castañeda-Sandoval, Laura M

    2015-07-01

    The aim of this research was to investigate the potential of a nutrient-rich organic waste, namely the cell-free supernatant of Bacillus thuringiensis (BtS) gathered from fermentation, as a biostimulating agent to improve and sustain microbial populations and their enzymatic activities, thereby assisting in the bioremediation of chlorpyrifos-contaminated soil at a high dose (70 mg kg(-1)). Experiments were performed for up to 80 d. Chlorpyrifos degradation and its major metabolic product, 3,5,6-trichloro-2-pyridinol (TCP), were quantified by high-performance liquid chromatography (HPLC); total microbial populations were enumerated by direct counts in specific medium; and fluorescein diacetate (FDA) hydrolysis was measured as an index of soil microbial activity. Throughout the experiment, there was higher chlorpyrifos degradation in soil supplemented with BtS (83.1%) as compared to non-supplemented soil. TCP formation and degradation occurred in all soils, but the greatest degradation (30.34%) was observed in soil supplemented with BtS. The total microbial populations were significantly improved by supplementation with BtS. The application of chlorpyrifos to soil inhibited the enzymatic activity; however, this negative effect was counteracted by BtS, inducing an increase of approximately 16% in FDA hydrolysis. These results demonstrate the potential of B. thuringiensis supernatant as a suitable biostimulation agent for enhancing chlorpyrifos and TCP biodegradation in chlorpyrifos-contaminated soils.

  11. Production of a recombinant laccase from Pichia pastoris and biodegradation of chlorpyrifos in a laccase/vanillin system.

    PubMed

    Xie, Huifang; Li, Qi; Wang, Minmin; Zhao, Linguo

    2013-06-28

    The recombinant strain P. pastoris GS115-lccC was used to produce laccase with high activity. Factors influencing laccase expression, such as pH, methanol concentration, copper concentration, peptone concentration, shaker rotate speed, and medium volume were investigated. Under the optimal conditions, laccase activity reached 12,344 U/L on day 15. The recombinant enzyme was purified by precipitating and dialyzing to electrophoretic homogeneity, and was estimated to have a molecular mass of about 58 kDa. When guaiacol was the substrate, the laccase showed the highest activity at pH 5.0 and was stable when the pH was 4.5~6.0. The optimal temperature for the laccase to oxidize guaiacol was 60°C, but it was not stable at high temperature. The enzyme could remain stable at 30°C for 5 days. The recombinant laccase was used to degrade chlorpyrifos in several laccase/mediator systems. Among three synthetic mediators (ABTS, HBT, VA) and three natural mediators (vanillin, 2,6-DMP, and guaiacol), vanillin showed the most enhancement on degradation of chlorpyrifos. Both laccase and vanillin were responsible for the degradation of chlorpyrifos. A higher dosage of vanillin may promote a higher level of degradation of chlorpyrifos, and the 2-step addition of vanillin led to 98% chlorpyrifos degradation. The degradation of chlorpyrifos was faster in the L/V system (kobs = 0.151) than that in the buffer solution (kobs = 0.028).

  12. Use of Bacillus thuringiensis supernatant from a fermentation process to improve bioremediation of chlorpyrifos in contaminated soils.

    PubMed

    Aceves-Diez, Angel E; Estrada-Castañeda, Kelly J; Castañeda-Sandoval, Laura M

    2015-07-01

    The aim of this research was to investigate the potential of a nutrient-rich organic waste, namely the cell-free supernatant of Bacillus thuringiensis (BtS) gathered from fermentation, as a biostimulating agent to improve and sustain microbial populations and their enzymatic activities, thereby assisting in the bioremediation of chlorpyrifos-contaminated soil at a high dose (70 mg kg(-1)). Experiments were performed for up to 80 d. Chlorpyrifos degradation and its major metabolic product, 3,5,6-trichloro-2-pyridinol (TCP), were quantified by high-performance liquid chromatography (HPLC); total microbial populations were enumerated by direct counts in specific medium; and fluorescein diacetate (FDA) hydrolysis was measured as an index of soil microbial activity. Throughout the experiment, there was higher chlorpyrifos degradation in soil supplemented with BtS (83.1%) as compared to non-supplemented soil. TCP formation and degradation occurred in all soils, but the greatest degradation (30.34%) was observed in soil supplemented with BtS. The total microbial populations were significantly improved by supplementation with BtS. The application of chlorpyrifos to soil inhibited the enzymatic activity; however, this negative effect was counteracted by BtS, inducing an increase of approximately 16% in FDA hydrolysis. These results demonstrate the potential of B. thuringiensis supernatant as a suitable biostimulation agent for enhancing chlorpyrifos and TCP biodegradation in chlorpyrifos-contaminated soils. PMID:25910975

  13. Electrochemical Determination of Chlorpyrifos on a Nano-TiO₂Cellulose Acetate Composite Modified Glassy Carbon Electrode.

    PubMed

    Kumaravel, Ammasai; Chandrasekaran, Maruthai

    2015-07-15

    A rapid and simple method of determination of chlorpyrifos is important in environmental monitoring and quality control. Electrochemical methods for the determination of pesticides are fast, sensitive, reproducible, and cost-effective. The key factor in electrochemical methods is the choice of suitable electrode materials. The electrode materials should have good stability, reproducibility, more sensitivity, and easy method of preparation. Mercury-based electrodes have been widely used for the determination of chlorpyrifos. From an environmental point of view mercury cannot be used. In this study a biocompatible nano-TiO2/cellulose acetate modified glassy carbon electrode was prepared by a simple method and used for the electrochemical sensing of chlorpyrifos in aqueous methanolic solution. Electroanalytical techniques such as cyclic voltammetry, differential pulse voltammetry, and amperometry were used in this work. This electrode showed very good stability, reproducibility, and sensitivity. A well-defined peak was obtained for the reduction of chlorpyrifos in cyclic voltammetry and differential pulse voltammetry. A smooth noise-free current response was obtained in amperometric analysis. The peak current obtained was proportional to the concentration of chlorpyrifos and was used to determine the unknown concentration of chlorpyrifos in the samples. Analytical parameters such as LOD, LOQ, and linear range were estimated. Analysis of real samples was also carried out. The results were validated through HPLC. This composite electrode can be used as an alternative to mercury electrodes reported in the literature.

  14. Spectrophotometric assays for the enzymatic hydrolysis of the active metabolites of chlorpyrifos and parathion by plasma paraoxonase/arylesterase.

    PubMed

    Furlong, C E; Richter, R J; Seidel, S L; Costa, L G; Motulsky, A G

    1989-08-01

    Human serum plasma paraoxonase/arylesterase exhibits a genetic polymorphism for the hydrolysis of paraoxon. One allelic form of the enzyme hydrolyzes paraoxon slowly with a low turnover number and the other(s) hydrolyzes paraoxon rapidly with a high turnover number. Chlorpyrifos-oxon, the active metabolite of the insecticide chlorpyrifos (Dursban), is also hydrolyzed by plasma arylesterase/paraoxonase. A specific assay for measuring hydrolysis of this compound is described. This assay is not subject to interference by the esterase activity of serum albumin. The Km for chlorpyrifos-oxon hydrolysis was 75 microM. Hydrolysis was inhibited by phenyl acetate, EDTA, and organic solvents. Enzyme activity required calcium ions and was stimulated by sodium chloride. Hydrolysis was optimized by using methanol instead of acetone to dissolve substrate. Unlike the multimodal distribution of paraoxonase, the distribution of chlorpyrifos-oxonase activity failed to show clear multimodality. An improvement in the assay for hydrolysis of paraoxon by plasma arylesterase/paraoxonase was achieved by elimination of organic solvents. Plotting chlorpyrifos-oxonase activity vs paraoxonase activity for a human population using the new assay conditions provided an excellent resolution of low activity homozygotes from heterozygotes for this allele. A greater than 40-fold difference in rates of chlorpyrifosoxon hydrolysis observed between rat (low activity) and rabbit sera (high activity) correlated well with the reported large differences in LD50 values for chlorpyrifos in these two animals, consistent with an important role of serum paraoxonase in detoxification of organophosphorus pesticides in vivo.

  15. [Study on the co-adsorption mechanism of Pb (II) and chlorpyrifos on arid loess in northwestern China].

    PubMed

    Fan, Chun-Hui; Zhang, Ying-Chao; Wang, Jia-Hong

    2013-08-01

    The co-adsorption characteristics of Pb(II) and chlorpyrifos on arid loess were investigated with batch adsorption procedures, and the co-adsorption mechanism was studied with approaches of SEM, FT-IR, XRD and theoretical analysis. The experimental results indicated that the adsorption process of Pb(II) and chlorpyrifos on loess fit better the Langmuir isotherm, the maximum adsorption capacity of q(m) is 12.5 and 0.64 mg x g(-1) for Pb(II) and chlorpyrifos on loess, respectively, and the reaction could be illustrated with pseudo-second order kinetic equation. The SEM micrograph of loess surface varies little after the adsorption process of Pb(II) and chlorpyrifos, and certain wave peaks of FTIR spectra red-shift, disappears or intensity-decrease, with the XRD pattern and theoretical analysis, the adsorption mechanism is described as follows: the adsorption of Pb (II) on arid loess is the chemical-effect of coordination-complexation and Van der Waals force; the physical-adsorption on chlorpyrifos involves the interception function, hydrogen bonds and Van der Waals force, and chemical adsorption effect to some extent. The organic matter in arid loess plays an important role in Pb(II) and chlorpyrifos adsorption.

  16. Changes of field incurred chlorpyrifos and its toxic metabolite residues in rice during food processing from-RAC-to-consumption.

    PubMed

    Zhang, Zhiyong; Jiang, Wayne W; Jian, Qiu; Song, Wencheng; Zheng, Zuntao; Wang, Donglan; Liu, Xianjin

    2015-01-01

    The objectives of this study were to determine the effects of food processing on field incurred residues levels of chlorpyrifos and its metabolite 3,5,6-Trichloro-2-pyridinol (TCP) in rice. The chlorpyrifos and TCP were found to be 1.27 and 0.093 mg kg-1 in straw and 0.41 and 0.073 mg kg-1 in grain, respectively. It is observed that the sunlight for 2 hours does not decrease the chlorpyrifos and TCP residues in grain significantly. Their residues in rice were reduced by up to 50% by hulling. The cooking reduced the chlorpyrifos and TCP in rice to undetectable level (below 0.01 mg kg-1). Processing factors (PFs) of chlorpyrifos and TCP residues in rice during food processing were similar. Various factors have impacts on the fates of chlorpyrifos and TCP residues and the important steps to reduce their residues in rice were hulling and cooking. The results can contribute to assure the consumer of a safe wholesome food supply.

  17. Exposure to Chlorpyrifos in Gaseous and Particulate Form in Greenhouses: A Pilot Study

    PubMed Central

    Kim, Seung Won; Lee, Eun Gyung; Lee, Taekhee; Lee, Larry A.; Harper, Martin

    2015-01-01

    Phase distribution of airborne chemicals is important because intake and uptake mechanisms of each phase are different. The phase distribution and concentrations are needed to determine strategies of exposure assessment, hazard control, and worker protection. However, procedures for establishing phase distribution and concentration have not been standardized. The objective of this study was to compare measurements of an airborne semivolatile pesticide (chlorpyrifos) by phase using two different procedures. Six pesticide applications in two facilities were studied and at each site, samples were collected for three time slots: T1, the first 1 or 2 hr after the commencement of application; T2, a 6-hr period immediately following T1; and T3, a 6-hr period after the required reentry interval (24 hr for chlorpyrifos). Two phase-separating devices were co-located at the center of each greenhouse: semivolatile aerosol dichotomous sampler (SADS) using flow rates of 1.8 l.min−1 and 0.2 l.min−1, corresponding to a total inlet flow rate of 2.0 l.min−1 with a vapor phase flow fraction of 0.1; and an electrostatic precipitator (ESP), along with a standard OVS XAD-2 tube. Chlorpyrifos in vapor and particulate form in a SADS sampling train and that in vapor form in an ESP sampling train were collected in OVS tubes. Chlorpyrifos in particulate form in the ESP setting would have been collected on aluminum substrate. However, no chlorpyrifos in particulate form was recovered from the ESP. Overall (vapor plus particle) concentrations measured by OVS ranged 11.7 – 186.6 μg/m3 at T1 and decreased on average 77.1% and 98.9% at T2 and T3, respectively. Overall concentrations measured by SADS were 66.6%, 72.7%, and 102% of those measured by OVS on average at T1, T2, and T3, respectively. Particle fractions from the overall concentrations measured by SADS were 60.0%, 49.2%, and 13.8%, respectively, for T1, T2, and T3. SADS gives better guidance on the distribution of chlorpyrifos

  18. Exposure to chlorpyrifos in gaseous and particulate form in greenhouses: a pilot study.

    PubMed

    Kim, Seung Won; Lee, Eun Gyung; Lee, Taekhee; Lee, Larry A; Harper, Martin

    2014-01-01

    Phase distribution of airborne chemicals is important because intake and uptake mechanisms of each phase are different. The phase distribution and concentrations are needed to determine strategies of exposure assessment, hazard control, and worker protection. However, procedures for establishing phase distribution and concentration have not been standardized. The objective of this study was to compare measurements of an airborne semivolatile pesticide (chlorpyrifos) by phase using two different procedures. Six pesticide applications in two facilities were studied and at each site, samples were collected for three time slots: T1, the first 1 or 2 hr after the commencement of application; T2, a 6-hr period immediately following T1; and T3, a 6-hr period after the required re-entry interval (24 hr for chlorpyrifos).Two phase-separating devices were co-located at the center of each greenhouse: semivolatile aerosol dichotomous sampler (SADS) using flow rates of 1.8 l x min(-1) and 0.2 l x min(-1), corresponding to a total inlet flow rate of 2.0 l x min(-1) with a vapor phase flow fraction of 0.1; and an electrostatic precipitator (ESP), along with a standard OVS XAD-2 tube. Chlorpyrifos in vapor and particulate form in a SADS sampling train and that in vapor form in an ESP sampling train were collected in OVS tubes. Chlorpyrifos in particulate form in the ESP setting would have been collected on aluminum substrate. However, no chlorpyrifos in particulate form was recovered from the ESP. Overall (vapor plus particle) concentrations measured by OVS ranged 11.7-186.6 μg/m(3) at T1 and decreased on average 77.1% and 98.9% at T2 and T3, respectively. Overall concentrations measured by SADS were 66.6%, 72.7%, and 102% of those measured by OVS on average at T1, T2, and T3, respectively. Particle fractions from the overall concentrations measured by SADS were 60.0%, 49.2%, and 13.8%, respectively, for T1, T2, and T3. SADS gives better guidance on the distribution of

  19. Evaluation of the Protective Effect of Silibinin Against Diazinon Induced Hepatotoxicity and Free-Radical Damage in Rat Liver

    PubMed Central

    Beydilli, Halil; Yilmaz, Nigar; Cetin, Esin Sakalli; Topal, Yasar; Celik, Ozgur Ilhan; Sahin, Cem; Topal, Hatice; Cigerci, Ibrahim Hakki; Sozen, Hamdi

    2015-01-01

    Background: Diazinon (0,0-Diethyl 0-(1-6-methyl-2-isoprophyl 4 pyrimidinyl) phosphorothioate) (DI) is a very effective organophosphate pesticide, used widely in agriculture. Consequently, data on poisoning cases secondary to DI exposure are important. The DI may affect a variety of tissues, including liver. Silibinin is a pharmacologically active constitute of Silybum marianum, with documented antioxidant activity. Objectives: The aim of our study was to evaluate both histopathologically and biochemically whether silibinin is protective in DI induced liver damage. Materials and Methods: Thirty two Wistar albino rats were divided into four groups, as follows: 1) control group - oral corn oil was given; 2) DI group - rats were administered orally 335 mg/kg in the corn oil solution; 3) Silibinin group - 100 mg/kg/day silibinin was given alone orally, every 24 hours for 7 days; 4) Silibinin + DI group - DI plus silibinin was given. All rats were sacrificed at the end of experiment. Superoxide dismutases (SOD), glutathione peroxidase (GPX), nitric oxide (NO) and myeloperoxidase (MPO) were investigated in serum and liver tissue. In addition, serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) enzyme activities were evaluated. The liver tissue was evaluated histopathologically with Hematoxilin & Eosin dye. Results: Biochemically, ALT, AST, NO, MPO in serum and NO, MPO in liver tissue were found to be significantly higher in DI group, compared to control group (P < 0.001). In Group Silibinin + DI, serum AST, ALT, NO, MPO levels were significantly lower (P < 0.01), and both serum and tissue SOD activities were significantly higher, compared to DI group (P < 0.001). Diazinon induced histopathological changes in liver tissue were: severe sinusoidal dilatation, moderate disruption of the radial alignment of hepatocytes around the central vein, severe vacuolization in the hepatocyte cytoplasm, inflammation around central vein and portal region. In rats

  20. Roles of uptake, biotransformation, and target site sensitivity in determining the differential toxicity of chlorpyrifos to second to fourth instar Chironomous riparius (Meigen)

    USGS Publications Warehouse

    Buchwalter, D.B.; Sandahl, J.F.; Jenkins, J.J.; Curtis, L.R.

    2004-01-01

    Early life stages of aquatic organisms tend to be more sensitive to various chemical contaminants than later life stages. This research attempted to identify the key biological factors that determined sensitivity differences among life stages of the aquatic insect Chironomous riparius. Specifically, second to fourth instar larvae were exposed in vivo to both low and high waterborne concentrations of chlorpyrifos to examine differences in accumulation rates, chlorpyrifos biotransformation, and overall sensitivity among instars. In vitro acetylcholinesterase (AChE) assays were performed with chlorpyrifos and the metabolite, chlorpyrifos-oxon, to investigate potential target site sensitivity differences among instars. Earlier instars accumulated chlorpyrifos more rapidly than later instars. There were no major differences among instars in the biotransformation rates of chlorpyrifos to the more polar metabolites, chlorpyrifos-oxon, and chlorpyridinol (TCP). Homogenate AChE activities from second to fourth instar larvae were refractory to chlorpyrifos, even at high concentrations. In contrast, homogenate AChE activities were responsive in a dose-dependent manner to chlorpyrifos-oxon. In general, it appeared that chlorpyrifos sensitivity differences among second to fourth instar C. riparius were largely determined by differences in uptake rates. In terms of AChE depression, fourth instar homogenates were more sensitive to chlorpyrifos and chlorpyrifos-oxon than earlier instars. However, basal AChE activity in fourth instar larvae was significantly higher than basal AChE activity in second to third instar larvae, which could potentially offset the apparent increased sensitivity to the oxon. ?? 2003 Elsevier B.V. All rights reserved.

  1. Interactive toxicity of chlorpyrifos and parathion in neonatal rats: Role of esterases in exposure sequence-dependent toxicity

    SciTech Connect

    Kacham, R.; Karanth, S.; Baireddy, P.; Liu, J.; Pope, C. . E-mail: carey.pope@okstate.edu

    2006-01-15

    We previously reported that sequence of exposure to chlorpyrifos and parathion in adult rats can markedly influence toxic outcome. In the present study, we evaluated the interactive toxicity of chlorpyrifos (8 mg/kg, po) and parathion (0.5 mg/kg, po) in neonatal (7 days old) rats. Rats were exposed to the insecticides either concurrently or sequentially (separated by 4 h) and sacrificed at 4, 8, and 24 h after the first exposure for biochemical measurements (cholinesterase activity in brain, plasma, and diaphragm and carboxylesterase activity in plasma and liver). The concurrently-exposed group showed more cumulative lethality (15/24) than either of the sequential dosing groups. With sequential dosing, rats treated initially with chlorpyrifos prior to parathion (C/P) exhibited higher lethality (7/23) compared to those treated with parathion before chlorpyrifos (P/C; 1/24). At 8 h after initial dosing, brain cholinesterase inhibition was significantly greater in the C/P group (59%) compared to the P/C group (28%). Diaphragm and plasma cholinesterase activity also followed a relatively similar pattern of inhibition. Carboxylesterase inhibition in plasma and liver was relatively similar among the treatment groups across time-points. Similar sequence-dependent differences in brain cholinesterase inhibition were also noted with lower binary exposures to chlorpyrifos (2 mg/kg) and parathion (0.35 mg/kg). In vitro and ex vivo studies compared relative oxon detoxification of carboxylesterases (calcium-insensitive) and A-esterases (calcium-sensitive) in liver homogenates from untreated and insecticide pretreated rats. Using tissues from untreated rats, carboxylesterases detoxified both chlorpyrifos oxon and paraoxon, while A-esterases only detoxified chlorpyrifos oxon. With parathion pretreatment, A-esterases still detoxified chlorpyrifos oxon while liver from chlorpyrifos pretreated rats had little apparent effect on paraoxon. We conclude that while neonatal rats are less

  2. Avoidance behaviour response and esterase inhibition in the earthworm, Lumbricus terrestris, after exposure to chlorpyrifos.

    PubMed

    Martínez Morcillo, S; Yela, J L; Capowiez, Y; Mazzia, C; Rault, M; Sanchez-Hernandez, Juan C

    2013-05-01

    The avoidance response of earthworms to polluted soils has been standardised using a simple and low-cost test, which facilitates soil toxicity screening. In this study, the avoidance response of Lumbricus terrestris was quantified in chlorpyrifos-spiked soils, depending on the pesticide concentration and exposure duration. The inhibition of acetylcholinesterase (AChE) and carboxylesterase (CbE) activities was also determined as indirect measures of pesticide bioavailability. The effects of different chlorpyrifos concentrations were examined in a standardised test (two-chamber system) with 0.6, 3 and 15 mg/kg chlorpyrifos. A modification of the test involved a pre-exposure step (24, 48 or 72 h) in soils spiked with 15 mg/kg. In both protocols, earthworms were unable to avoid the contaminated soils. However, the esterase activities showed that all earthworms were exposed to chlorpyrifos. Acetylcholinesterase activity did not change in earthworms in the standardised behavioural test (0.58 ± 0.20 U/mg protein, mean ± SD; n = 72), whereas the CbE activity was significantly inhibited (62-87 % inhibition) in earthworms exposed to 3 and 15 mg/kg. In the modified test, earthworms had greatly inhibited AChE activity (0.088 ± 0.034 U/mg protein, n = 72), which was supported by reactivation of the inhibited enzyme activity in the presence of pralidoxime (2-PAM). Similarly, the CbE activity was significantly inhibited in earthworms with all treatments. This study suggests that the avoidance behaviour test for organophosphorus-contaminated soils could be supported by specific biomarkers to facilitate a better understanding of pesticide exposure and toxicity during this test. PMID:23435687

  3. An evaluation of the inhibition of human butyrylcholinesterase and acetylcholinesterase by the organophosphate chlorpyrifos oxon

    SciTech Connect

    Shenouda, Josephine; Green, Paula; Sultatos, Lester

    2009-12-01

    Acetylcholinesterase (EC 3.1.1.7) and butyrylcholinesterase (EC 3.1.1.8) are enzymes that belong to the superfamily of alpha/beta-hydrolase fold proteins. While they share many characteristics, they also possess many important differences. For example, whereas they have about 54% amino acid sequence identity, the active site gorge of acetylcholinesterase is considerably smaller than that of butyrylcholinesterase. Moreover, both have been shown to display simple and complex kinetic mechanisms, depending on the particular substrate examined, the substrate concentration, and incubation conditions. In the current study, incubation of butyrylthiocholine in a concentration range of 0.005-3.0 mM, with 317 pM human butyrylcholinesterase in vitro, resulted in rates of production of thiocholine that were accurately described by simple Michaelis-Menten kinetics, with a K{sub m} of 0.10 mM. Similarly, the inhibition of butyrylcholinesterase in vitro by the organophosphate chlorpyrifos oxon was described by simple Michaelis-Menten kinetics, with a k{sub i} of 3048 nM{sup -1} h{sup -1}, and a K{sub D} of 2.02 nM. In contrast to inhibition of butyrylcholinesterase, inhibition of human acetylcholinesterase by chlorpyrifos oxon in vitro followed concentration-dependent inhibition kinetics, with the k{sub i} increasing as the inhibitor concentration decreased. Chlorpyrifos oxon concentrations of 10 and 0.3 nM gave k{sub i}s of 1.2 and 19.3 nM{sup -1} h{sup -1}, respectively. Although the mechanism of concentration-dependent inhibition kinetics is not known, the much smaller, more restrictive active site gorge of acetylcholinesterase almost certainly plays a role. Similarly, the much larger active site gorge of butyrylcholinesterase likely contributes to its much greater reactivity towards chlorpyrifos oxon, compared to acetylcholinesterase.

  4. Sub-lethal Effects of Chlorpyrifos on Big Brown Bats (Eptesicus fuscus).

    PubMed

    Eidels, Ronny R; Sparks, Daniel W; Whitaker, John O; Sprague, Charles A

    2016-10-01

    We determined dose-response curves for sublethal effects of the organophosphorus (OP) insecticide, chlorpyrifos, on bats. Big brown bats (Eptesicus fuscus, n = 64) were given a single dose of chlorpyrifos (nominal concentrations) of 0, 5, 10, 15, 20, 25, 30, or 60 µg/g body weight and examined at 12 or 24 h after dosing. A second experiment dosed 32 bats with 0 or 60 µg/g body weight and examined 1, 3, 7, or 14 days after dosing. Skin temperature and behavioral changes were recorded, and brain and plasma cholinesterase (ChE) activity were measured. The benchmark dose (BMD10) of chlorpyrifos that altered brain and plasma ChE activity at 24 h was 3.7 and 10.1 µg/g, respectively. The 95 % lower confidence limit for the BMD10 (i.e., BMDL10) was 1.6 and 7.7 µg/g. The best of five models (as determined by AIC) for impaired flight, impaired movement, or presence of tremors provided a BMD10 of 6.2, 12.9, and 7.8 µg/g body weight of chlorpyrifos, respectively. BMDL10 for impaired flight, impaired movement, or presence of tremors was 3.5, 6.6, and 5.3 µg/g body weight, respectively. In the wild, impaired ability to fly or crawl could be life-threatening. Brain and plasma ChE activity remained low for 3 days after dosing. Gradual recovery of enzyme activity was observed by 7 days in survivors. Brain and plasma ChE activity were still significantly lower than that of the control group at 14 days after dosing. PMID:27491870

  5. Aqueous-phase disappearance of atrazine, metolachlor, and chlorpyrifos in laboratory aquaria and outdoor macrocosms

    USGS Publications Warehouse

    Mazanti, L.; Rice, C.; Bialek, K.; Sparling, D.; Stevenson, C.; Johnson, W.E.; Kangas, P.; Rheinstein, J.

    2003-01-01

    Dissipation processes are described for a combination of commonly used pesticides--atrazine (6-chloro-4--ethylamino-6-isopropylamino-s-triazine), metolachlor (2-chloro-N-[2-ethyl-6-methyl-phenyl]-N-[2-methoxy-l-methylethyl] acetamide), and chlorpyrifos (O-O diethyl O-[3,5,6-trichloro-2-pyridinyl] phosphorothioate)--in a laboratory and outdoor pond systems. Dosing rates and timing were designed to duplicate those common in the mid-Atlantic Coastal Plain, USA. Treatment ranged from 2 and 2.5 mg/L to 0.2 and 0.25 mg/L respectively for atrazine and metolachlor, and chlorpyrifos was added at 1.0 and 0.1 mg/L in the aquaria and at 0.1 mg/L in the outdoor macrocosms. Chlorpyrifos disappearance was rapid in all of the systems and followed a two-phase sequence. Initial half-lives varied from 0.16 da), to 0.38 day and showed similar rates in the aquaria and the outdoor systems. The second phase of the chlorpyrifos loss pattern was slower (18-20 days) in all the treatments except for the low herbicide treatment in the outdoor test, where it was 3.4 days. Compared to the outdoor system, herbicide losses were much slower in the aquaria, e.g., 150 days for atrazine and 55 days for metolachlor, and no appreciable loss of herbicide was apparent in the high-treated aquaria. In the outdoor systems, the half-lives for the low herbicide treatment were 27 days and 12 days, respectively, for atrazine and metolachlor, and 48 and 20 days, respectively for the high herbicide-treated pond. Very low levels of CIAT (6-amino-2-chloro-4-iso-propylamino-s-triazine) and CEAT (2-chloro-4-ethylamino-6-ethylamino-s-triazine), degradation products of atrazine, were observed in the outdoor studies.

  6. Protective effect of crocin against apoptosis induced by subchronic exposure of the rat vascular system to diazinon.

    PubMed

    Razavi, Bibi Marjan; Hosseinzadeh, Hossein; Abnous, Khalil; Khoei, Alireza; Imenshahidi, Mohsen

    2016-07-01

    Research has suggested that natural antioxidant, crocin, an active ingredient of saffron, may protect against diazinon (DZN)-induced toxicity. Although increased production of lipid peroxidation by DZN in rat aorta has been shown previously, the effects of DZN on oxidative stress-induced apoptosis in vascular system have not been evaluated. In this study, the effect of crocin on DZN-induced apoptosis in rat vascular system was investigated. The rats were divided into 7 groups: corn oil (control), DZN (15 mg/kg/day, gavage), crocin (12.5, 25, and 50 mg/kg/day, intraperitoneally (i.p.)) + DZN, vitamin E (200 IU/kg, i.p., 3 days a week) + DZN, and crocin (50 mg/kg/day, i.p.). The treatments were continued for 4 weeks. Levels of apoptotic (Bax, caspase 3, and caspase 9) and antiapoptotic proteins (Bcl2) were analyzed by Western blotting. Transcript levels of Bax and Bcl2 genes were determined using quantitative real-time polymerase chain reaction. Results showed DZN-induced apoptosis by activation of caspase 9 and caspase 3 and by increasing the Bax/Bcl2 ratio (both protein and messenger RNA levels). Crocin and vitamin E inhibited apoptosis induced by DZN. In summary, subchronic exposure to DZN induced caspase-mediated apoptosis, and crocin reduced the toxic effects of DZN by inhibiting apoptosis in aortic tissue. PMID:27353299

  7. Effect of aqueous extract of Crocus sativus L. (saffron) stigma against subacute effect of diazinon on specific biomarkers in rats.

    PubMed

    Moallem, Seyed Adel; Hariri, Alireza Timcheh; Mahmoudi, Mahmoud; Hosseinzadeh, Hossein

    2014-03-01

    In this study, the effect of aqueous extract of Crocus sativus L. (saffron) stigma was studied against subacute toxicity of diazinon (DZN) on specific biochemical markers in rats. Vitamin E (200 IU/kg) and the aqueous extract of saffron at doses 50, 100 and 200 mg/kg were injected intraperitoneally three times per week alone or with DZN (20 mg/kg/day, orally) for 4 weeks. Red blood cell (RBC) cholinesterase activity was inhibited by DZN and this effect was not affected by vitamin E or saffron plus DZN. The levels of serum tumor necrosis factor-α (inflammation marker), direct 8-iso-prostaglandin F(2α) (oxidative stress marker) and soluble protein-100 β (S100β, neuronal damage marker) were increased significantly by DZN. The saffron extract inhibited the effect of DZN on these biomarkers levels. However, vitamin E was able to only reduce 8-iso-prostaglandin F(2α) and S100β levels. This study showed that the aqueous extract of saffron prevents DZN-induced rise of several specific inflammation, oxidative stress and neuronal damage biomarkers.

  8. Protective effect of crocin against apoptosis induced by subchronic exposure of the rat vascular system to diazinon.

    PubMed

    Razavi, Bibi Marjan; Hosseinzadeh, Hossein; Abnous, Khalil; Khoei, Alireza; Imenshahidi, Mohsen

    2016-07-01

    Research has suggested that natural antioxidant, crocin, an active ingredient of saffron, may protect against diazinon (DZN)-induced toxicity. Although increased production of lipid peroxidation by DZN in rat aorta has been shown previously, the effects of DZN on oxidative stress-induced apoptosis in vascular system have not been evaluated. In this study, the effect of crocin on DZN-induced apoptosis in rat vascular system was investigated. The rats were divided into 7 groups: corn oil (control), DZN (15 mg/kg/day, gavage), crocin (12.5, 25, and 50 mg/kg/day, intraperitoneally (i.p.)) + DZN, vitamin E (200 IU/kg, i.p., 3 days a week) + DZN, and crocin (50 mg/kg/day, i.p.). The treatments were continued for 4 weeks. Levels of apoptotic (Bax, caspase 3, and caspase 9) and antiapoptotic proteins (Bcl2) were analyzed by Western blotting. Transcript levels of Bax and Bcl2 genes were determined using quantitative real-time polymerase chain reaction. Results showed DZN-induced apoptosis by activation of caspase 9 and caspase 3 and by increasing the Bax/Bcl2 ratio (both protein and messenger RNA levels). Crocin and vitamin E inhibited apoptosis induced by DZN. In summary, subchronic exposure to DZN induced caspase-mediated apoptosis, and crocin reduced the toxic effects of DZN by inhibiting apoptosis in aortic tissue.

  9. Bird predation on cutworms (Lepidoptera: Noctuidae) in wheat fields and chlorpyrifos effects on brain cholinesterase activity

    USGS Publications Warehouse

    McEwen, L.C.; DeWeese, L.R.; Schladweiler, P.

    1986-01-01

    Horned larks, Eremophila alpestris (L.), and McCown's longspurs, Calcarius mccownii (Lawrence), were collected at intervals from two winter wheat fields in Montana [USA] after aerial application of chlorpyrifos to control cutworms. Both bird species had a high (95-100%) incidence of Lepidoptera, mostly pale western cutworms, Agrotis orthogonia Morrison, in their stomachs at 3 days postspray. Incidence of cutworms and other insects in stomachs of birds from sprayed fields was lower at 9 and 16 days postspray than in control birds, presumably due to insecticide-caused reduction of insects. Effects of birds on population dynamics of insect pests in wheat are unknown, but birds do contribute to cutworm mortality. Predation is one of the limiting factors to cutworm increase and can supplement insecticidal control. Brain cholinesterase activity in horned larks collected from the sprayed fields at 3 and 9 days postspray was significantly lower than in unexposed larks, but at 16 days the difference was not significant. Although nontarget birds clearly were exposed to chlorpyrifos and manifested a sublethal physiological response, toxic effects were less severe than those resulting from endrin application for cutworm control in wheat. More study is needed of larger chlorpyrifos-treated fields under a variety of conditions to fully assess effects on nontarget life.

  10. Cannabinoid CB1 receptor as a target for chlorpyrifos oxon and other organophosphorus pesticides.

    PubMed

    Quistad, Gary B; Nomura, Daniel K; Sparks, Susan E; Segall, Yoffi; Casida, John E

    2002-09-01

    Binding of the endocannabinoid anandamide or of Delta(9)-tetrahydrocannabinol to the agonist site of the cannabinoid receptor (CB1) is commonly assayed with [3H]CP 55,940. Potent long-chain alkylfluorophosphonate inhibitors of agonist binding suggest an additional, important and closely-coupled nucleophilic site, possibly undergoing phosphorylation. We find that the CB1 receptor is also sensitive to inhibition in vitro and in vivo by several organophosphorus pesticides and analogs. Binding of [3H]CP 55,940 to mouse brain CB1 receptor in vitro is inhibited 50% by chlorpyrifos oxon at 14 nM, chlorpyrifos methyl oxon at 64 nM and paraoxon, diazoxon and dichlorvos at 1200-4200 nM. Some 15 other organophosphorus pesticides and analogs are less active in vitro. The plant defoliant tribufos inhibits CB1 in vivo, without cholinergic poisoning signs, by 50% at 50 mg/kg intraperitoneally with a recovery half-time of 3-4 days, indicating covalent derivatization. [3H-ethyl]Chlorpyrifos oxon may be suitable for radiolabeling and characterization of this proposed nucleophilic site. PMID:12243867

  11. Impact of single and repeated applications of the insecticide chlorpyrifos on tropical freshwater plankton communities.

    PubMed

    Daam, Michiel A; Van den Brink, Paul J; Nogueira, António J A

    2008-11-01

    This paper describes the effects of a single and a repeated application of the organophosphorus insecticide chlorpyrifos on zooplankton and phytoplankton communities in outdoor microcosms in Thailand. Treatment levels of 1 microg L(-1) were applied once or twice with a 2-week interval. Both treatments led to a significant decrease in cladocerans followed by an increase in rotifers, although the extent by which species were affected was different. Ceriodaphnia cornuta was the most responding cladoceran after the first treatment, while Moina micrura responded most to the second. This is explained by differences in the growth phase of M. micrura at the time of application and an increase in Microcystis abundance over the course of the experiment. Several phytoplankton taxa either increased or decreased as a result of the chlorpyrifos-induced changes in zooplankton communities. Even though chlorpyrifos disappeared fast from the water column, effects on plankton communities persisted till the end of the experiment (42 days) when the insecticide concentrations had dropped below the detection limit. This was presumably due to the increasing population trend of Microcystis, favouring rotifers over cladocerans. PMID:18498053

  12. Genotoxic effects of commercial formulations of Chlorpyrifos and Tebuconazole on green algae.

    PubMed

    Martinez, Ricardo Santiago; Di Marzio, Walter Darío; Sáenz, María Elena

    2015-01-01

    The alkaline single-cell gel electrophoresis assay (comet assay) was used for the study of the genotoxic effects of insecticide Chlorpyrifos and fungicide Tebuconazole (commercial formulations) on two freshwater green algae species, Pseudokirchneriella subcapitata and Nannocloris oculata, after 24 h of exposure. The percentage of DNA in tail of migrating nucleoids was taken as an endpoint of DNA impairment. Cell viability was measured by fluorometric detection of chlorophyll "a" in vivo and the determination of cell auto-fluorescence. Only the higher concentration of Chlorpyrifos tested resulted to affect significantly the cell viability of P. subcapitata, whereas cells of N. oculata were not affected. Tebuconazole assayed concentrations (3 and 6 mg/l) did not affect cell viability of both species. The results of comet assay on P. subcapitata showed that Chlorpyrifos concentration evaluated (0.8 mg/l) exerted a genotoxic effects; while for the other specie a concentration of 10 mg/l was needed. Tebuconazole was genotoxic at 3 and 6 mg/l for both species. The comet assay evidenced damage at the level of DNA simple strains molecule at pesticide concentrations were cytotoxicity was not evident, demonstrating that algae are models to take into account in ecological risk assessments for aquatic environments. PMID:25230876

  13. Cannabinoid CB1 receptor as a target for chlorpyrifos oxon and other organophosphorus pesticides.

    PubMed

    Quistad, Gary B; Nomura, Daniel K; Sparks, Susan E; Segall, Yoffi; Casida, John E

    2002-09-01

    Binding of the endocannabinoid anandamide or of Delta(9)-tetrahydrocannabinol to the agonist site of the cannabinoid receptor (CB1) is commonly assayed with [3H]CP 55,940. Potent long-chain alkylfluorophosphonate inhibitors of agonist binding suggest an additional, important and closely-coupled nucleophilic site, possibly undergoing phosphorylation. We find that the CB1 receptor is also sensitive to inhibition in vitro and in vivo by several organophosphorus pesticides and analogs. Binding of [3H]CP 55,940 to mouse brain CB1 receptor in vitro is inhibited 50% by chlorpyrifos oxon at 14 nM, chlorpyrifos methyl oxon at 64 nM and paraoxon, diazoxon and dichlorvos at 1200-4200 nM. Some 15 other organophosphorus pesticides and analogs are less active in vitro. The plant defoliant tribufos inhibits CB1 in vivo, without cholinergic poisoning signs, by 50% at 50 mg/kg intraperitoneally with a recovery half-time of 3-4 days, indicating covalent derivatization. [3H-ethyl]Chlorpyrifos oxon may be suitable for radiolabeling and characterization of this proposed nucleophilic site.

  14. Developmental and polyamine metabolism alterations in Rhinella arenarum embryos exposed to the organophosphate chlorpyrifos.

    PubMed

    Sotomayor, Verónica; Lascano, Cecilia; de D'Angelo, Ana María Pechen; Venturino, Andrés

    2012-09-01

    Organophosphorus pesticides (OPs) are widely applied in the Alto Valle of Río Negro and Neuquén, Argentina, due to intensive fruit growing. Amphibians are particularly sensitive to environmental pollution, and OPs may transiently accumulate in ponds and channels of the region during their reproductive season. Organophosphorus pesticide exposure may alter amphibian embryonic development and the reproductive success of autochthonous species. In the present study, embryos of the common toad Rhinella arenarum were employed to assess developmental alterations and to study polyamine metabolism, which is essential to normal growth, as a possible target underlying the effects of the OP chlorpyrifos. As the duration of chlorpyrifos exposure increased and embryonic development progressed, the median lethal concentration (LC50) values decreased, and the percentage of malformed embryos increased. Developmental arrest was also observed and several morphological alterations were recorded, such as incomplete and abnormal closure of the neural tube, dorsal curvature of the caudal fin, reduction of body size and caudal fin length, atrophy, and edema. An early decrease in ornithine decarboxylase (ODC) activity and polyamine levels was also observed in embryos exposed to chlorpyrifos. The decrease in polyamine contents in tail bud embryos might be a consequence of the reduction in ODC activity. The alteration of polyamine metabolism occurred before embryonic growth was interrupted and embryonic malformations were observed and may be useful as a biomarker in environmental studies.

  15. Degradation of Chlorpyrifos by an alkaline phosphatase from the cyanobacterium Spirulina platensis.

    PubMed

    Thengodkar, Rutwik Ravindra Mandakini; Sivakami, S

    2010-07-01

    Spirulina is a photosynthetic, filamentous, spiral-shaped, multicellular, blue-green microalga. The two most important species are Spirulina maxima and Spirulina platensis. Spirulina is considered an excellent food, lacking toxicity and having corrective properties against viral attacks, anemia, tumor growth and malnutrition. We have observed that cultures of Spirulina platensis grow in media containing up to 80 ppm of the organophosphorous pesticide, Chlorpyrifos. It was found to be due to an alkaline phosphatase (ALP) activity that was detected in cell free extracts of Spirulina platensis. This activity was purified from the cell free extracts using ammonium sulphate precipitation and gel filtration and shown to belong to the class of EC 3.1.3.1 ALP. The purified enzyme degrades 100 ppm Chlorpyrifos to 20 ppm in 1 h transforming it into its primary metabolite 3, 5, 6-trichloro-2-pyridinol. This is the first report of degradation of Chlorpyrifos by Spirulina platensis whose enzymic mechanism has been clearly identified. These findings have immense potential for harnessing Spirulina platensis in bioremediation of polluted ecosystems. PMID:20127145

  16. The expression of proteins involved in digestion and detoxification are regulated in Helicoverpa armigera to cope up with chlorpyrifos insecticide.

    PubMed

    Dawkar, Vishal V; Chikate, Yojana R; More, Tushar H; Gupta, Vidya S; Giri, Ashok P

    2016-02-01

    Helicoverpa armigera is a key pest in many vital crops, which is mainly controlled by chemical strategies. To manage this pest is becoming challenging due to its ability and evolution of resistance against insecticides. Further, its subsequent spread on nonhost plant is remarkable in recent times. Hence, decoding resistance mechanism against phytochemicals and synthetic insecticides is a major challenge. The present work describes that the digestion, defense and immunity related enzymes are associated with chlorpyrifos resistance in H. armigera. Proteomic analysis of H. armigera gut tissue upon feeding on chlorpyrifos containing diet (CH) and artificial diet (AD) using nano-liquid chromatography-mass spectrometry identified upregulated 23-proteins in CH fed larvae. Database searches combined with gene ontology analysis revealed that the identified gut proteins engrossed in digestion, proteins crucial for immunity, adaptive responses to stress, and detoxification. Biochemical and quantitative real-time polymerase chain reaction analysis of candidate proteins indicated that insects were struggling to get nutrients and energy in presence of CH, while at the same time endeavoring to metabolize chlorpyrifos. Moreover, we proposed a potential processing pathway of chlorpyrifos in H. armigera gut by examining the metabolites using gas chromatography-mass spectrometry. H. armigera exhibit a range of intriguing behavioral, morphological adaptations and resistance to insecticides by regulating expression of proteins involved in digestion and detoxification mechanisms to cope up with chlorpyrifos. In these contexts, as gut is a rich repository of biological information; profound analysis of gut tissues can give clues of detoxification and resistance mechanism in insects.

  17. An Amperometric Immunosensor Based on Multi-Walled Carbon Nanotubes-Thionine-Chitosan Nanocomposite Film for Chlorpyrifos Detection

    PubMed Central

    Sun, Xia; Cao, Yaoyao; Gong, Zhili; Wang, Xiangyou; Zhang, Yan; Gao, Jinmei

    2012-01-01

    In this work, a novel amperometric immunosensor based on multi-walled carbon nanotubes-thionine-chitosan (MWCNTs-THI-CHIT) nanocomposite film as electrode modified material was developed for the detection of chlorpyrifos residues. The nanocomposite film was dropped onto a glassy carbon electrode (GCE), and then the anti-chlorpyrifos monoclonal antibody was covalently immobilized onto the surface of MWCNTs-THI-CHIT/GCE using the crosslinking agent glutaraldehyde (GA). The modification procedure was characterized by using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Under the optimized conditions, a linear relationship between the relative change in peak current of different pulse voltammetry (DPV) and the logarithm of chlorpyrifos solution concentration was obtained in the range from 0.1 to 1.0 × 105 ng/mL with a detection limit of 0.046 ng/mL. The proposed chlorpyrifos immunosensor exhibited high reproducibility, stability, and good selectivity and regeneration, making it a potential alternative tool for ultrasensitive detection of chlorpyrifos residues in vegetables and fruits. PMID:23443396

  18. Removal of Chlorpyrifos by Water Hyacinth (Eichhornia crassipes) and the Role of a Plant-Associated Bacterium.

    PubMed

    Anudechakul, Choochai; Vangnai, Alisa S; Ariyakanon, Naiyanan

    2015-01-01

    The objective of this research was to study the efficiency of water hyacinth (Eichhornia crassipes) and the role of any plant-associated bacteria in removing chlorpyrifos from water. The relative growth rate (RGR) of E. crassipes in the presence of 0.1 mg/L chlorpyrifos was not significantly different from that in its absence and only slightly decreased at concentrations of 0.5 and 1.0 mg/L by ∼1.1- and ∼1.2-fold, respectively, with an observed dry weight based RGRDW for E. crassipes of 0.036-0.041 mg/g/d. The removal rate constants of chlorpyrifos in the absence of plants were low at 3.52, 2.29 and 1.84 h(-1) for concentrations of 0.1, 0.5 and 1.0 mg/L, respectively, but were some 3.89- to 4.87-fold higher in the presence of E. crassipes. Chlorpyrifos removal was markedly facilitated by the presence of a root-associated bacterium, preliminarily identified as Acinetobacter sp. strain WHA. The interaction of E. crassipes and Acinetobacter sp. strain WHA provide an efficient and ecological alternative to accelerate the removal and degradation of chlorpyrifos pollution from aquatic systems including wastewater. PMID:25976881

  19. Uptake and loss of chlorpyrifos and atrazine by Juncus effusus l. in a mesocosm study with a mixture of pesticides.

    PubMed

    Lytle, Julia S; Lytle, Thomas F

    2002-09-01

    Abstract-Aquatic organisms in agricultural regions typically are exposed to mixtures of agrochemicals, and effects are not adequately predicted from results of single pesticide exposure studies. Thus, a mesocosm study was designed to examine the fate and effects of varying mixtures of three pesticides (chlorpyrifos, atrazine, and monosodium methanearsonate) and mercury-contaminated sediment to the common freshwater macrophyte Juncus effusus L. Exposure doses of pesticides added to mesocosms represented those that might be encountered in a typical runoff or direct spray application. This study reports the uptake and loss of chlorpyrifos and atrazine in the leaves of J. effusus after a single and a repeated dose of the chemical mixture over 94 d. The measured chlorpyrifos levels in leaves were highest on day 1, but levels in both leaves and water dropped rapidly and were at background levels by day 32. Atrazine remained near nominal concentrations in the water through day 16 and reached maximum accumulation in the leaves on day 16. The chemical mixture affected uptake of chlorpyrifos more strongly than atrazine as measured by differences in uptake variability. After the second dose, J. effusus showed a similar uptake pattern for both compounds, although somewhat faster, to that observed after the first dose, with no diminished capacity for uptake of either compound. The greater volatility of chlorpyrifos, the higher solubility of atrazine, and the more efficient transport of atrazine to the root zone are characteristics that are consistent with the differences observed in their uptake and loss behavior.

  20. Respiratory strategy is a major determinant of [3H]water and [14C]chlorpyrifos uptake in aquatic insects

    USGS Publications Warehouse

    Buchwalter, D.B.; Jenkins, J.J.; Curtis, L.R.

    2002-01-01

    Despite the extensive use of aquatic insects to evaluate freshwater ecosystem health, little is known about the underlying factors that result in sensitivity differences between taxa. Organismal characteristics (respiratory strategy and body size) were used to explore the rates of [3H]H2O and [14)C]chlorpyrifos accumulation in aquatic insects. Ten aquatic insect taxa, including ephemeropteran, trichopteran, dipteran, hemipteran, and coleopteran species, were exposed to [14C]chlorpyrifos (240 ng??L-1) and [3H]H2O for up to 12 h. Because exchange epithelial surfaces on the)integument are permeable to water, [3H]H2O was used as a quantitative surrogate for exposed cellular surface area.) [14C]Chlorpyrifos uptake rates were highly correlated with water permeability in all 10 taxa tested and largely covaried with body size and respiratory strategy. Rates were highest among smaller organisms on a per-weight basis and in taxa with relatively large external cellular surfaces such as gills. Air-breathing taxa were significantly less permeable to both [3)HH20 and [14C)C]chlorpyrifos. A method for labeling exposed epithelial surfaces with a fluorescent dye was developed. This technique allowed discrimination between exchange epithelium and barrier tissue on the integument. Fluorescent dye distributions on the body surface provided a rapid method for estimating exposed epithelium consistent with [3H]H2O and [14)C]chlorpyrifos accumulation.

  1. CHLORPYRIFOS ACCUMULATION PATTERNS FOR CHILD ACCESSIBLE SURFACES AND OBJECTIVES AND URINARY METABOLITE EXCRETION BY CHILDREN FOR TWO-WEEKS AFTER CRACK-AND-CREVICE APPLICATION

    EPA Science Inventory

    The Children's-Post-Pesticide-Application-Exposure-Study (CPPAES) was conducted to look at the distribution of chlorpyrifos within a home environment for a 2-week period following a routine professional crack-and-crevice application, and to determine the amount of the chlorpyrifo...

  2. Failure of Intravenous Lipid Emulsion to Reduce Diazinon-induced Acute Toxicity: a Pilot Study in Rats.

    PubMed

    Moshiri, Mohammad; Vahabzadeh, Maryam; Etemad, Leila; Hosseinzadeh, Hossein

    2013-01-01

    Diazinon (DZN) is a synthetic organophosphorus (OPs) insecticide widely used in agricultural and household applications. OPs, particularly DZN, are highly lipid soluble liquids. Intravenous lipid emulsion (ILE) has been shown to reduce toxicity caused by some lipid soluble agents. We evaluated the antidote effect of ILE on acute toxicity of DZN. Twenty-four Sprague-Dawley female rats weighting 200-250 g were treated orally with dose of 480 mg/ kg of DZN gavaged at the volume of 0.5 mL/kg. Thirty minutes after administration of DZN, two groups were treated by either ILE 10% (ILE10) or normal saline (NS) (16 mL/kg) (NS16) that were infused for the duration of 15 minutes. Another two groups were also treated by either ILE 20% (ILE20) or NS (10 mL/kg: NS10) as above. The changes in body weight, diarrhea score, muscular power, fasciculation, convulsions and mortality rate of the animals were all monitored immediately after infusions and then every 6 h up to 48 h. There was no significant difference in animals mean weight between different groups during the observation period. In addition, during the 48-hour observation we could not find any difference in muscular power and diarrhea score between groups of ILE20-NS10 and ILE10-NS16 in comparison with each other, and neither ILE 10% nor ILE %20 could not reduce mortality rate of animals or increase the survival time of rats. In conclusion, ILE seems to be unable to reverse DZN acute toxicity and it might be due to conversion of DZN to potent and less lipid soluble agent. PMID:24523769

  3. Failure of Intravenous Lipid Emulsion to Reduce Diazinon-induced Acute Toxicity: a Pilot Study in Rats

    PubMed Central

    Moshiri, Mohammad; Vahabzadeh, Maryam; Etemad, Leila; Hosseinzadeh, Hossein

    2013-01-01

    Diazinon (DZN) is a synthetic organophosphorus (OPs) insecticide widely used in agricultural and household applications. OPs, particularly DZN, are highly lipid soluble liquids. Intravenous lipid emulsion (ILE) has been shown to reduce toxicity caused by some lipid soluble agents. We evaluated the antidote effect of ILE on acute toxicity of DZN. Twenty-four Sprague-Dawley female rats weighting 200-250 g were treated orally with dose of 480 mg/ kg of DZN gavaged at the volume of 0.5 mL/kg. Thirty minutes after administration of DZN, two groups were treated by either ILE 10% (ILE10) or normal saline (NS) (16 mL/kg) (NS16) that were infused for the duration of 15 minutes. Another two groups were also treated by either ILE 20% (ILE20) or NS (10 mL/kg: NS10) as above. The changes in body weight, diarrhea score, muscular power, fasciculation, convulsions and mortality rate of the animals were all monitored immediately after infusions and then every 6 h up to 48 h. There was no significant difference in animals mean weight between different groups during the observation period. In addition, during the 48-hour observation we could not find any difference in muscular power and diarrhea score between groups of ILE20-NS10 and ILE10-NS16 in comparison with each other, and neither ILE 10% nor ILE %20 could not reduce mortality rate of animals or increase the survival time of rats. In conclusion, ILE seems to be unable to reverse DZN acute toxicity and it might be due to conversion of DZN to potent and less lipid soluble agent. PMID:24523769

  4. Transferable residues from dog fur and plasma cholinesterase inhibition in dogs treated with a flea control dip containing chlorpyrifos.

    PubMed

    Boone, J S; Tyler, J W; Chambers, J E

    2001-11-01

    We studied chlorpyrifos, an insecticide present in a commercial dip for treating ectoparasites in dogs, to estimate the amount of transferable residues that children could obtain from their treated pets. Although the chlorpyrifos dip is no longer supported by the manufacturer, the methodology described herein can help determine transferable residues from other flea control insecticide formulations. Twelve dogs of different breeds and weights were dipped using the recommended guidelines with a commercial, nonprescription chlorpyrifos flea dip for 4 consecutive treatments at 3-week intervals (nonshampoo protocol) and another 12 dogs were dipped with shampooing between dips (shampoo protocol). The samples collected at 4 hr and 7, 14, and 21 days after treatment in the nonshampoo protocol averaged 971, 157, 70, and 26 microg chlorpyrifos, respectively; in the shampoo protocol the samples averaged 459, 49, 15, and 10 microg, respectively. The highest single sample was about 7,000 microg collected at 4 hr. The pretreatment specific activities in the plasma of the dogs were about 75 nmol/min/mg protein for butyrylcholinesterase (BChE), and 9 nmol/min/mg protein for acetylcholinesterase (AChE). BChE was inhibited 50-75% throughout the study, and AChE was inhibited 11-18% in the nonshampoo protocol; inhibition was not as great in the shampoo protocol. There was no correlation (pchlorpyrifos to chlorpyrifos-oxon. Plasma cholinesterase activity did not return to control levels during the 3-week period. The differences between the shampoo and nonshampoo protocols were explained by differences in the techniques of the dip

  5. Influence of two insecticides, chlorpyrifos and quinalphos, on arginine ammonification and mineralizable nitrogen in two tropical soil types.

    PubMed

    Menon, Pramila; Gopal, Madhuban; Prasad, Rajender

    2004-12-01

    Effects of seed treatments with chlorpyrifos [5 g of active ingredient (ai) kg(-1) of seed] and quinalphos (6.25 g of ai kg(-1) of seed) and standing crop treatments with chlorpyrifos (800 g of ai ha(-1)) and quinalphos (1000 g of ai ha(-1)) on arginine deamination and mineralizable nitrogen were monitored, in the sandy loam and loamy sand soils of two tropical semiarid fields, for three consecutive crop seasons. The arginine ammonification activity of rhizospheric microbes was inhibited after seed treatment with chlorpyrifos and quinalphos and their principal metabolites, 3,5,6-trichloro-2-pyridinol (TCP) and 3,5,6-trichloro-2-methoxypyridine (TMP) and 2-hydroxyquinoxaline and quinoxaline-2-thiol, respectively. Quinalphos produced transient inhibitions, whereas chlorpyrifos and its metabolites (TCP and TMP) exerted a greater inhibition in both loamy sand and sandy loam soils. Arginine ammonification by nonrhizospheric microbes was stimulated by standing crop treatments with both pesticides. In the loamy sand soil, the parent compounds stimulated rhizospheric N-mineralization, whereas the metabolites were inhibitory. However, nonrhizospheric N-mineralization was inhibited by both chlorpyrifos and quinalphos and stimulated by their metabolites. A higher magnitude of inhibition of arginine deamination in the loamy sand than in the sandy loam soil could be due to greater bioavailability of the pesticides in the former, resulting from lesser sorption of the pesticides due to alkalinity of the soil and its low content of clay and organic carbon. Although both pesticides affected mineralizable nitrogen, seed treatment with quinalphos and standing crop treatment with quinalphos and chlorpyrifos produced the most significant effects. The recommended doses of the pesticides not only efficiently controlled whitegrubs, which increased pod yields, but also left no residues in harvested kernels. They also caused no long-term inhibition of ammonification, which could have been

  6. Degradation of pesticides chlorpyrifos, cypermethrin and chlorothalonil in aqueous solution by TiO2 photocatalysis.

    PubMed

    Affam, Augustine Chioma; Chaudhuri, Malay

    2013-11-30

    Degradation of pesticides chlorpyrifos, cypermethrin and chlorothalonil in aqueous solution by TiO2 photocatalysis under UVA (365 nm) irradiation was examined. Enhancement of degradation and improvement in biodegradability index (BOD5/COD ratio) by H2O2 addition were also evaluated. UVA irradiation per se produced insignificant degradation of the pesticides. In UV/TiO2 photocatalysis (TiO2 1.5 g L(-1), pH 6 and 300 min irradiation), COD and TOC removal were 25.95 and 8.45%, respectively. In UV/TiO2/H2O2 photocatalysis (TiO2 1.5 g L(-1), H2O2 100 mg L(-1), pH 6 and 300 min irradiation), COD and TOC removal were 53.62 and 21.54%, respectively and biodegradability index improved to 0.26. Ammonia-nitrogen (NH3-N) decreased from 22 to 7.8 mg L(-1) and nitrate-nitrogen (NO3(-)-N) increased from 0.7 to 13.8 mg L(-1) in 300 min, indicating mineralization. Photocatalytic degradation followed pseudo-first order kinetics with rate constant (k) of 0.0025 and 0.0008 min(-1) for COD and TOC removal, respectively. FTIR spectra indicated degradation of the organic bonds of the pesticides. UV/TiO2/H2O2 photocatalysis is effective in degradation of pesticides chlorpyrifos, cypermethrin and chlorothalonil in aqueous solution. UV/TiO2/H2O2 photocatalysis may be applied as pretreatment of a chlorpyrifos, cypermethrin and chlorothalonil pesticide wastewater at pH 6, for biological treatment.

  7. Effect of In Vivo Nicotine Exposure on Chlorpyrifos Pharmacokinetics and Pharmacodynamics in Rats

    SciTech Connect

    Lee, Sookwang; Poet, Torka S.; Smith, Jordan N.; Busby-Hjerpe, Andrea L.; Timchalk, Charles

    2010-03-30

    Routine use of tobacco products may modify physiological and metabolic functions, including drug metabolizing enzymes, which may impact the pharmacokinetics of environmental contaminants. Chlorpyrifos is an organophosphorus (OP) insecticide that is bioactivated to chlorpyrifos-oxon, and manifests its neurotoxicity by inhibiting acetylcholinesterase (AChE). The objective of this study was to evaluate the impact of repeated nicotine exposure on the pharmacokinetics of chlorpyrifos (CPF) and its major metabolite, 3,5,6-trichloro-2-pyridinol (TCPy) in blood and urine and also to determine the impact on cholinesterase (ChE) activity in plasma and brain. Animals were exposed to 7-daily doses of either 1 mg nicotine/kg or saline (sc), and to either a single oral dose of 35 mg CPF/kg or a repeated dose of 5 mg CPF/kg/day for 7 days. Groups of rats were then sacrificed at multiple time-points after receiving the last dose of CPF. Repeated nicotine and CPF exposures resulted in enhanced metabolism of CPF to TCPy, as evidenced by increases in the measured TCPy concentration and AUC in blood. However, there was no significant difference in the amount of TCPy (free or total) excreted in the urine. The extent of brain acetylcholinesterase (AChE) inhibition was reduced due to nicotine co-exposure consistent with an increase in CYP450-mediated dearylation (detoxification) versus desulfuration. It was of interest to note that the impact of nicotine co-exposure was experimentally observed only after repeated CPF doses. Physiologically based pharmacokinetic model simulations of CPF-oxon concentrations in blood and brain were predicted to be lower in nicotine treated groups, which were simulated by increasing the dearylation Vmax based upon previously conducted in vitro metabolism studies. These results were consistent with the experimental data. The current study demonstrated that repeated nicotine exposure could alter CPF metabolism in vivo, further modulating brain AChE inhibition.

  8. Joint toxicity of chlorpyrifos, atrazine, and cadmium at lethal concentrations to the earthworm Eisenia fetida.

    PubMed

    Yang, Guiling; Chen, Chen; Wang, Yanhua; Cai, Leiming; Kong, Xiangzhen; Qian, Yongzhong; Wang, Qiang

    2015-06-01

    Contaminants in the environment often occur as complex mixtures, and their combined effect may exhibit toxicity to organisms. Risk assessments based on individual components tend to underestimate the effects associated with toxic action of mixtures. Toxicity studies on chemical mixtures are urgently required to assess their potential combined toxicities. The combination index (CI)-isobologram method was used to study chemical interactions to determine the nature of toxicological interactions of two pesticides chlorpyrifos and atrazine and a heavy metal cadmium toward earthworm Eisenia fetida by artificial soil and filter paper acute toxicity tests. The results showed that the binary mixture of chlorpyrifos and atrazine was antagonistic toward E. fetida at all f a levels in an artificial soil test. The combination of atrazine and Cd exhibited a slight degree of synergism throughout the exposure range, while chlorpyrifos plus Cd combination led to dual antagonistic/synergistic behavior. The nature of binary combinations in filter paper displayed opposite interaction to that in the artificial soil test, and the toxicity of ternary mixtures was not significantly synergistic than their binaries. The combination index (CI)-isobologram equation method could determine the interaction types for a series of effect levels of three chemicals in binary and ternary combinations in two types of acute earthworm tests. However, the nature of these interactions was not uniform along the f a level range in any of the two tests. Bioavailability, the nature of toxicological interaction, and the test organism need to be considered for understanding exposures and chemical measures. The synergistic effect for the particular binary combination suggests that a potential risk associated with the co-occurrence of these pollutants may still exist, which may have implications in risk assessment for the terrestrial environment. The combined effects between different contaminants might be

  9. Potential chlorpyrifos exposure to residents following standard crack and crevice treatment.

    PubMed Central

    Byrne, S L; Shurdut, B A; Saunders, D G

    1998-01-01

    Multipathway exposures were evaluated for residents of houses over a 10-day period following a crack and crevice application of a chlorpyrifos-based formulation. Three multiroom houses with two adults each were treated. Air concentration, total deposition, and dislodgeable residues on horizontal surfaces were measured to assess potential respiratory, oral, and dermal exposures, respectively, in treated and untreated high activity rooms. In addition, urine samples collected from the adults were analyzed for the primary metabolite of chlorpyrifos, 3,5,6-trichloropyridinol, to determine absorbed dose. The maximum chlorpyrifos air concentration observed was 2.3 microgram/m3, with air concentrations generally decreasing to levels ranging from 0.1 to 0.3 microgram/m3 within 10 days. Carpet dislodgeable residues, used to evaluate the amount of residues potentially transferred upon contact, were less than the analytical method limit of quantitation (1.6 microgram/m2). Hard plastic balls placed in the homes on the day before application contained no detectable dislodgeable residues (<6.5 microgram/m2). Ten-day cumulative nontarget residues deposited on surfaces, as determined by deposition pads, were less than 2.3 microgram/100 cm2. Deposition samples from all living area floors collected 2 hr after application contained less than 9.9 microgram/100 cm2. Therefore, contact with household surfaces and subsequent hand-to-mouth activity are not expected to significantly contribute to overall exposure. Estimated exposures to children, based on the passive dosimetry measurements, ranged from 0.26 to 2.1% of the no observed effect level for plasma cholinesterase depression. In addition, potential exposures to the adult residents, as indicated by the urinary 3,5,6-TCP biomonitoring, did not increase as a result of the application. Images Figure 1 PMID:9799188

  10. Comparative effects of chlorpyrifos in wild type and cannabinoid Cb1 receptor knockout mice

    SciTech Connect

    Baireddy, Praveena; Liu, Jing; Hinsdale, Myron; Pope, Carey

    2011-11-15

    Endocannabinoids (eCBs) modulate neurotransmission by inhibiting the release of a variety of neurotransmitters. The cannabinoid receptor agonist WIN 55.212-2 (WIN) can modulate organophosphorus (OP) anticholinesterase toxicity in rats, presumably by inhibiting acetylcholine (ACh) release. Some OP anticholinesterases also inhibit eCB-degrading enzymes. We studied the effects of the OP insecticide chlorpyrifos (CPF) on cholinergic signs of toxicity, cholinesterase activity and ACh release in tissues from wild type (+/+) and cannabinoid CB1 receptor knockout (-/-) mice. Mice of both genotypes (n = 5-6/treatment group) were challenged with CPF (300 mg/kg, 2 ml/kg in peanut oil, sc) and evaluated for functional and neurochemical changes. Both genotypes exhibited similar cholinergic signs and cholinesterase inhibition (82-95% at 48 h after dosing) in cortex, cerebellum and heart. WIN reduced depolarization-induced ACh release in vitro in hippocampal slices from wild type mice, but had no effect in hippocampal slices from knockouts or in striatal slices from either genotype. Chlorpyrifos oxon (CPO, 100 {mu}M) reduced release in hippocampal slices from both genotypes in vitro, but with a greater reduction in tissues from wild types (21% vs 12%). CPO had no significant in vitro effect on ACh release in striatum. CPF reduced ACh release in hippocampus from both genotypes ex vivo, but reduction was again significantly greater in tissues from wild types (52% vs 36%). In striatum, CPF led to a similar reduction (20-23%) in tissues from both genotypes. Thus, while CB1 deletion in mice had little influence on the expression of acute toxicity following CPF, CPF- or CPO-induced changes in ACh release appeared sensitive to modulation by CB1-mediated eCB signaling in a brain-regional manner. -- Highlights: Black-Right-Pointing-Pointer C57Bl/6 mice showed dose-related cholinergic toxicity following subcutaneous chlorpyrifos exposure. Black-Right-Pointing-Pointer Wild type and

  11. Simultaneous subchronic exposure to selenium and diazinon as possible risk factor for osteoporosis in adult male rats

    PubMed Central

    2013-01-01

    Background Osteoporosis and its main health outcome, fragility fractures, are large and escalating health problems. Skeletal damage may be the critical result of low-level prolonged exposure to several xenobiotics in the general population, but the mechanisms of their adverse effects are not clearly understood. The current study was aimed to investigate the possible ability of simultaneous subchronic peroral administration of selenium (Se) and diazinon (DZN) to induce changes in bone of adult male rats. In our study, twenty 1-month-old male Wistar rats were randomly divided into two experimental groups. In the first group, young males were exposed to 5 mg Na2SeO3/L and 40 mg of DZN/L in drinking water, for 90 days. Ten 1-month-old males without Se and DZN intoxication served as a control group. At the end of the experiment, macroscopic and microscopic structures of the femurs were analysed using analytical scales, sliding instrument, and polarized light microscopy. Results The body weight, femoral length and cortical bone thickness were significantly decreased in rats simultaneously exposed to Se and DZN (P < 0.05). These rats also displayed different microstructure in the middle part of the compact bone where vascular canals expanded into central area of substantia compacta. The canals occurred only near endosteal surfaces in rats from the control group. Additionally, a smaller number of primary and secondary osteons, as well as a few resorption lacunae were observed near endosteal surfaces in rats simultaneously administered to Se and DZN. The resorption lacunae as typical structures of bone resorption manifestation are connected with an early stage of osteoporosis. Histomorphometric analysis revealed that area, perimeter, maximum and minimum diameters of primary osteons’ vascular canals were significantly increased (P < 0.05) in the Se-DZN-exposed rats. On the other hand, all measured variables of Haversian canals and secondary osteons were

  12. Measurements of Chlorpyrifos Levels in Forager Bees and Comparison with Levels that Disrupt Honey Bee Odor-Mediated Learning Under Laboratory Conditions.

    PubMed

    Urlacher, Elodie; Monchanin, Coline; Rivière, Coraline; Richard, Freddie-Jeanne; Lombardi, Christie; Michelsen-Heath, Sue; Hageman, Kimberly J; Mercer, Alison R

    2016-02-01

    Chlorpyrifos is an organophosphate pesticide used around the world to protect food crops against insects and mites. Despite guidelines for chlorpyrifos usage, including precautions to protect beneficial insects, such as honeybees from spray drift, this pesticide has been detected in bees in various countries, indicating that exposure still occurs. Here, we examined chlorpyrifos levels in bees collected from 17 locations in Otago, New Zealand, and compared doses of this pesticide that cause sub-lethal effects on learning performance under laboratory conditions with amounts of chlorpyrifos detected in the bees in the field. The pesticide was detected at 17 % of the sites sampled and in 12 % of the colonies examined. Amounts detected ranged from 35 to 286 pg.bee(-1), far below the LD50 of ~100 ng.bee(-1). We detected no adverse effect of chlorpyrifos on aversive learning, but the formation and retrieval of appetitive olfactory memories was severely affected. Chlorpyrifos fed to bees in amounts several orders of magnitude lower than the LD50, and also lower than levels detected in bees, was found to slow appetitive learning and reduce the specificity of memory recall. As learning and memory play a central role in the behavioral ecology and communication of foraging bees, chlorpyrifos, even in sublethal doses, may threaten the success and survival of this important insect pollinator. PMID:26872472

  13. Changes in mouse liver and chicken embryo yolk sac membrane soluble proteins due to an organophosphorous insecticide (OPI) diazinon linked to several noncholinergic OPI effects in mice and chicken embryos.

    PubMed

    Seifert, Josef

    2014-11-01

    The objective of this study was to identify proteins in mouse livers and chicken embryo yolk sac membranes whose quantities were altered by an organophosphorous insecticide (OPI) treatment and which might be linked, based on their functionality, to the recognized noncholinergic effects of OPI. Mice and fertile chicken eggs were treated with an OPI representative diazinon. The quantitative changes in mouse liver and chicken embryo yolk sac membrane soluble proteins caused by diazinon were determined by two-dimensional electrophoresis. Proteins whose quantity was affected by diazinon were identified by the mass spectrometry. In mouse livers, the altered levels of several enzymes of glucose metabolism were considered with regards to amelioration of hyperglycemia due to diazinon; the reduced levels of 3-hydroxyanthranilate 3,4-dioxygenase to the changes in the l-tryptophan to NAD metabolism caused by pyrimidinyl and crotonamide OPI; the reduced levels of catalase, peroxiredoxin and superoxide dismutase to OPI-increased lipid and/or kynurenine oxidation, the latter effect resulting also in increased urinary excretion of xanthurenic and kynurenic acids; and an increase in glutathione S-methyltransferase to OPI detoxification. In chicken embryo yolk sac membranes, the reduced availability of procollagen-proline dioxygenase may be the factor in micromelia caused by OPI in chicken embryos.

  14. Internal Concentration and Time Are Important Modifiers of Toxicity: The Case of Chlorpyrifos on Caenorhabditis elegans.

    PubMed

    Roh, Ji-Yeon; Lee, Hyun-Jeoung; Kwon, Jung-Hwan

    2016-09-01

    The internal concentration of chemicals in exposed organisms changes over time due to absorption, distribution, metabolism, and excretion processes since chemicals are taken up from the environment. Internal concentration and time are very important modifiers of toxicity when biomarkers are used to evaluate the potential hazards and risks of environmental pollutants. In this study, the responses of molecular biomarkers, and the fate of chemicals in the body, were comprehensively investigated to determine cause-and-effect relationships over time. Chlorpyrifos (CP) was selected as a model chemical, and Caenorhabditis elegans was exposed to CP for 4 h using the passive dosing method. Worms were then monitored in fresh medium during a 48-h recovery regime. The mRNA expression of genes related to CYP metabolism (cyp35a2 and cyp35a3) increased during the constant exposure phase. The body residue of CP decreased once it reached a peak level during the early stage of exposure, indicating that the initial uptake of CP rapidly induced biotransformation with the synthesis of new CYP metabolic proteins. The residual chlorpyrifos-oxon concentration, an acetylcholinesterase (AChE) inhibitor, continuously increased even after the recovery regime started. These delayed toxicokinetics seem to be important for the extension of AChE inhibition for up to 9 h after the start of the recovery regime. Comprehensive investigation into the molecular initiation events and changes in the internal concentrations of chemical species provide insight into response causality within the framework of an adverse outcome pathway.

  15. Peak centiles of chlorpyrifos surface-water concentrations in the NAWQA and NASQAN programs.

    PubMed

    Mosquin, Paul L; Aldworth, Jeremy; Poletika, Nicholas N

    2015-02-01

    We provide upper bound estimates for peak centiles of surface water chlorpyrifos concentration readings within spatial, temporal, and land-use domains of the United States Geological Survey (USGS) National Water-Quality Assessment (NAWQA) and National Stream Quality Accounting Network (NASQAN) programs. These datasets have large overall sample sizes but variable sampling frequencies and, for chlorpyrifos, extremely high levels of non-detections. Point and interval estimates are provided for the 90th, 95th, 99th, and the 99.9th centiles, given sufficient sample size. Overall upper bound estimates for the NAWQA program over the period 1992-2011 for the 90th, 95th, 99th, and 99.9th centiles are <0.005, 0.0066, 0.0214, and 0.0852 ug/L, respectively. The estimation method is based on a survey sampling approach, finding centiles of pooled data across aggregates of site-years. Although the population quantity estimated by a pooled data centile is not the easily interpretable average of population site-year centiles, we provide strong support that it bounds this average by a combination of theory, comparison of NAWQA aggregate and direct estimates, and using modeled populations.

  16. Developmental neurotoxic effects of two pesticides: Behavior and biomolecular studies on chlorpyrifos and carbaryl.

    PubMed

    Lee, Iwa; Eriksson, Per; Fredriksson, Anders; Buratovic, Sonja; Viberg, Henrik

    2015-11-01

    In recent times, an increased occurrence of neurodevelopmental disorders, such as neurodevelopmental delays and cognitive abnormalities has been recognized. Exposure to pesticides has been suspected to be a possible cause of these disorders, as these compounds target the nervous system of pests. Due to the similarities of brain development and composition, these pesticides may also be neurotoxic to humans. We studied two different pesticides, chlorpyrifos and carbaryl, which specifically inhibit acetylcholinesterase (AChE) in the nervous system. The aim of the study was to investigate if the pesticides can induce neurotoxic effects, when exposure occurs during a period of rapid brain growth and maturation. The results from the present study show that both compounds can affect protein levels in the developing brain and induce persistent adult behavior and cognitive impairments, in mice neonatally exposed to a single oral dose of chlorpyrifos (0.1, 1.0 or 5mg/kg body weight) or carbaryl (0.5, 5.0 or 20.0mg/kg body weight) on postnatal day 10. The results also indicate that the developmental neurotoxic effects induced are not related to the classical mechanism of acute cholinergic hyperstimulation, as the AChE inhibition level (8-12%) remained below the threshold for causing systemic toxicity. The neurotoxic effects are more likely caused by a disturbed neurodevelopment, as similar behavioral neurotoxic effects have been reported in studies with pesticides such as organochlorines, organophosphates, pyrethroids and POPs, when exposed during a critical window of neonatal brain development.

  17. Internal Concentration and Time Are Important Modifiers of Toxicity: The Case of Chlorpyrifos on Caenorhabditis elegans.

    PubMed

    Roh, Ji-Yeon; Lee, Hyun-Jeoung; Kwon, Jung-Hwan

    2016-09-01

    The internal concentration of chemicals in exposed organisms changes over time due to absorption, distribution, metabolism, and excretion processes since chemicals are taken up from the environment. Internal concentration and time are very important modifiers of toxicity when biomarkers are used to evaluate the potential hazards and risks of environmental pollutants. In this study, the responses of molecular biomarkers, and the fate of chemicals in the body, were comprehensively investigated to determine cause-and-effect relationships over time. Chlorpyrifos (CP) was selected as a model chemical, and Caenorhabditis elegans was exposed to CP for 4 h using the passive dosing method. Worms were then monitored in fresh medium during a 48-h recovery regime. The mRNA expression of genes related to CYP metabolism (cyp35a2 and cyp35a3) increased during the constant exposure phase. The body residue of CP decreased once it reached a peak level during the early stage of exposure, indicating that the initial uptake of CP rapidly induced biotransformation with the synthesis of new CYP metabolic proteins. The residual chlorpyrifos-oxon concentration, an acetylcholinesterase (AChE) inhibitor, continuously increased even after the recovery regime started. These delayed toxicokinetics seem to be important for the extension of AChE inhibition for up to 9 h after the start of the recovery regime. Comprehensive investigation into the molecular initiation events and changes in the internal concentrations of chemical species provide insight into response causality within the framework of an adverse outcome pathway. PMID:27490261

  18. Opuntia ficus indica extract protects against chlorpyrifos-induced damage on mice liver.

    PubMed

    Ncibi, Saida; Ben Othman, Mahmoud; Akacha, Amira; Krifi, Mohamed Naceur; Zourgui, Lazhar

    2008-02-01

    This original study investigates the role of Opuntia ficus indica (cactus) cladodes extract against liver damage induced in male SWISS mice by an organophosphorous insecticide, the chlorpyrifos (CPF). Liver damage was evaluated by the measure of its weight and the quantification of some biochemical parameters, such as alanine amino transferase (ALAT), aspartate amino transferase (ASAT), phosphatase alkaline (PAL), lactate dehydrogenase (LDH), cholesterol and albumin in serum by spectrophotometric techniques. The experimental approach lasted 48 h and consisted of 6 treatments of six mice each one; (1) control, (2) 10 mg/kg (b.w) CPF, (3) 10mg/kg (b.w) CPF with 100 mg/kg (b.w) cactus, (4) 150 mg/kg (b.w)CPF, (5) 150 mg/kg (b.w) CPF with 1.5 g/kg cactus, (6) 1.5 g/kg cactus. Both chlorpyrifos and cactus were administrated orally via gavages. Our results showed that CPF affects significantly all parameters studied. However, when this pesticide was administrated associated to cactus, we noticed a recovery of all their levels. In the other hand, cactus alone did not affect the studied parameters. These results allow us to conclude firstly that CPF is hepatotoxic and secondly that Opuntia ficus indica stem extract protects the liver and decreases the toxicity induced by this organophosphorous pesticide.

  19. Pilot biomonitoring of adults and children following use of chlorpyrifos shampoo and flea collars on dogs.

    PubMed

    Dyk, Melinda Bigelow; Chen, Zhenshan; Mosadeghi, Sasan; Vega, Helen; Krieger, Robert

    2011-01-01

    Pesticide handlers and pet owners who use products such as shampoos and dips and insecticide-impregnated collars to treat and control fleas on companion animals are exposed to a variety of active ingredients. Chlorpyrifos exposures of adults and children were measured using urine biomonitoring following use of over-the-counter products on dogs. Age and gender-specific measurements of urinary 3, 5, 6-trichloro-2-pyridinol (TCPy) revealed modest elevations of biomarker excretion following shampoo/dips. Smaller TCPy increments were measured following application of impregnated dog collars. The extent of indoor activity and potential pet contact were important determinants of urine biomarker level. Children without direct pet contact excreted more TCPy following collar application. Pet collars may be a source of indoor surface contamination and human exposure. Children excreted up to 4 times more TCPy than adults when urine volumes were adjusted using age-specific creatinine excretion levels. Although chlorpyrifos is no longer used in the United States in pet care products, results of this research provide perspective on the extent of human exposure from similar pet care products. These pilot studies demonstrated that pet care products such as insecticidal shampoos and dips and impregnated collars may expose family members to low levels of insecticide relative to toxic levels of concern.

  20. Opuntia ficus indica extract protects against chlorpyrifos-induced damage on mice liver.

    PubMed

    Ncibi, Saida; Ben Othman, Mahmoud; Akacha, Amira; Krifi, Mohamed Naceur; Zourgui, Lazhar

    2008-02-01

    This original study investigates the role of Opuntia ficus indica (cactus) cladodes extract against liver damage induced in male SWISS mice by an organophosphorous insecticide, the chlorpyrifos (CPF). Liver damage was evaluated by the measure of its weight and the quantification of some biochemical parameters, such as alanine amino transferase (ALAT), aspartate amino transferase (ASAT), phosphatase alkaline (PAL), lactate dehydrogenase (LDH), cholesterol and albumin in serum by spectrophotometric techniques. The experimental approach lasted 48 h and consisted of 6 treatments of six mice each one; (1) control, (2) 10 mg/kg (b.w) CPF, (3) 10mg/kg (b.w) CPF with 100 mg/kg (b.w) cactus, (4) 150 mg/kg (b.w)CPF, (5) 150 mg/kg (b.w) CPF with 1.5 g/kg cactus, (6) 1.5 g/kg cactus. Both chlorpyrifos and cactus were administrated orally via gavages. Our results showed that CPF affects significantly all parameters studied. However, when this pesticide was administrated associated to cactus, we noticed a recovery of all their levels. In the other hand, cactus alone did not affect the studied parameters. These results allow us to conclude firstly that CPF is hepatotoxic and secondly that Opuntia ficus indica stem extract protects the liver and decreases the toxicity induced by this organophosphorous pesticide. PMID:17980473

  1. Chlorpyrifos and cypermethrin induce apoptosis in human neuroblastoma cell line SH-SY5Y.

    PubMed

    Raszewski, Grzegorz; Lemieszek, Marta Kinga; Łukawski, Krzysztof; Juszczak, Małgorzata; Rzeski, Wojciech

    2015-02-01

    Our previous in vivo studies showed that chlorpyrifos (CPF) and cypermethrin (CM) in a mixture dermally administered, strongly inhibited cholinesterase activity in plasma and the brain and were very toxic to the rat central nervous system. In this work, the mechanisms of neurotoxicity have not been elucidated. We used human undifferentiated SH-SY5Y cells to study mechanisms of pesticide-induced neuronal cell death. It was found that chlorpyrifos (CPF) and its mixture with cypermethrin (CPF+CM) induced cell death of SH-SY5Y cells in a dose- and time-dependent manner, as shown by MTT assays. Pesticide-induced SH-SY5Y cell death was characterized by concentration-dependent down-regulation of Bcl-2 and Bcl-xL as well as an increase in the caspase 3 activation. Pan-caspase inhibitor Q-VD-OPh produced a slight but significant reversal effect of pesticide-induced toxicity indicating that the major caspase pathways are not integral to CPF- and CPF+CM-induced cell death. Furthermore, signal transduction inhibitors PD98059, SL-327, SB202190, SP600125 and mecamylamine failed to attenuate pesticides effect. Atropine exhibited minimal ability to reverse toxicity. Finally, it was shown that inhibition of TNF-α by pomalidomide attenuated CPF-/CPF+CM-induced apoptosis. Overall, our data suggest that FAS/TNF signalling pathways may participate in CPF and CPF+CM toxicity.

  2. Kinetics of biotransformation of chlorpyrifos in aqueous and soil slurry environments.

    PubMed

    Tiwari, Manoj K; Guha, Saumyen

    2014-03-15

    The attenuation of chlorpyrifos (CPF) by the enriched indigenous soil microorganism was studied in 15 d aerobic and 60 d anaerobic batch experiments in aqueous and soil slurry (1:3 w/w) media. At the end of the batch experiments, 2.78 ± 0.11 μM of CPF was degraded by 82% in aerobic and 66% in anaerobic aqueous environments, while 12.4 ± 0.5 μM of CPF was degraded by 48% in aerobic and 31% in anaerobic soil slurries. The reduced degradation in the soil slurries was due to the significantly (2-10 times) slower rate of degradation of soil phase CPF compared with its degradation rate in water. The pathways of degradation of CPF were identified, including a partial anaerobic degradation pathway that is constructed for the first time. The simulation of the various conversions in the degradation pathways using first order kinetics was used to analyze relative persistence of metabolites. The common metabolite 3,5,6-trichloro-2-pyridinol (TCP) accumulated (increased monotonically during the period of experiments) in aerobic soil slurry and in anaerobic aqueous as well as soil slurry systems but did not accumulate in aerobic aqueous system. The most toxic compound in the pathway, chlorpyrifos oxon (CPFO) was not detected in anaerobic environment. In aerobic environment, CPFO was short lived in aqueous medium, but accumulated slowly in the soils.

  3. Peak centiles of chlorpyrifos surface-water concentrations in the NAWQA and NASQAN programs.

    PubMed

    Mosquin, Paul L; Aldworth, Jeremy; Poletika, Nicholas N

    2015-02-01

    We provide upper bound estimates for peak centiles of surface water chlorpyrifos concentration readings within spatial, temporal, and land-use domains of the United States Geological Survey (USGS) National Water-Quality Assessment (NAWQA) and National Stream Quality Accounting Network (NASQAN) programs. These datasets have large overall sample sizes but variable sampling frequencies and, for chlorpyrifos, extremely high levels of non-detections. Point and interval estimates are provided for the 90th, 95th, 99th, and the 99.9th centiles, given sufficient sample size. Overall upper bound estimates for the NAWQA program over the period 1992-2011 for the 90th, 95th, 99th, and 99.9th centiles are <0.005, 0.0066, 0.0214, and 0.0852 ug/L, respectively. The estimation method is based on a survey sampling approach, finding centiles of pooled data across aggregates of site-years. Although the population quantity estimated by a pooled data centile is not the easily interpretable average of population site-year centiles, we provide strong support that it bounds this average by a combination of theory, comparison of NAWQA aggregate and direct estimates, and using modeled populations. PMID:25497425

  4. Stimulating effects of the insecticide chlorpyrifos on host searching and infestation efficacy of a parasitoid wasp.

    PubMed

    Rafalimanana, Halitiana; Kaiser, Laure; Delpuech, Jean-Marie

    2002-04-01

    Hymenopterous parasitoids play an important role in the control of insect populations. During oviposition, Hymenopterous parasitoids use cues such as odours from their environment to locate their specific host. Leptopilina heterotoma (parasitoid of Drosophila larvae) locate their host by probing the substrate with the ovipositor. This behaviour can be induced by the odour of the host substrate alone. We analysed the sub-lethal effects of chlorpyrifos at LD20 on the probing activity in response to a fruit odour (banana). The insecticide increased the percentage of females spontaneously probing in response to the odour. Parasitoid females were then conditioned to associate banana odour with the oviposition in host larvae. This conditioning enables parasitoids to memorize the odour and to increase their probing response to this odour. During the olfactory conditioning, females exposed to the insecticide found and oviposited in host larvae more quickly than control females. One hour after the olfactory conditioning, females exposed to the insecticide presented a higher increase of their probing response to the odour than controls. Twenty-four hours after conditioning, the stimulation produced by chlorpyrifos was no longer perceptible, but the level of response of conditioned females was still higher than that of non-conditioned females, showing that odour memory was not impaired by the insecticide treatment. These sub-lethal effects, that stimulate host searching by parasitoids without impairing odour memorization, could increase their parasitic efficiency. PMID:11975179

  5. Histopathological alterations in gill, liver and kidney of common carp exposed to chlorpyrifos.

    PubMed

    Pal, Sandipan; Kokushi, Emiko; Koyama, Jiro; Uno, Seiichi; Ghosh, Apurba R

    2012-01-01

    Histopathological alterations in gill, liver and kidney of common carp, Cyprinus carpio, intoxicated with sub-lethal concentrations of chlorpyrifos (O,O,-diethyl-O-3,5,6-trichloro-2-pyridyl phosphorothioate) pesticide (1 and 100 μg/L) for a period of 14 days were analyzed under light microscope. Gill exhibited hyperplasia and hypertrophy of gill epithelium, blood congestion, dilation of marginal channel, epithelial lifting, lamellar fusion, lamellar disorganization, lamellar aneurysm, rupture of the lamellar epithelium, rupture of pillar cells and necrosis. Alterations in hepatocytes were more pronounced, including nuclear and cellular hypertrophy, cellular atrophy, irregular contour of cells and nucleus, cytoplasmic vacuolation, cytoplasmic and nuclear degeneration, cellular rupture, pyknotic nucleus, necrosis and melanomacrophages aggregations. Histopathological lesions in kidney were cellular and nuclear hypertrophy, narrowing of tubular lumen, cytoplasmic vacuolation, hyaline droplet degeneration, nuclear degeneration, occlusion of tubular lumen, tubular regeneration, dilation of glomerular capillaries, degeneration of glomerulus and hemorrhage in Bowman's space. The most significant conclusion drawn from this study was that with the increased concentration and duration the toxicosis of chlorpyrifos would be enhanced as shown through the analysis of mean assessment value (MAV) and degree of tissue changes (DTC) also.

  6. Biodegradation of chlorpyrifos and its hydrolysis product 3,5,6-trichloro-2-pyridinol by a new fungal strain Cladosporium cladosporioides Hu-01.

    PubMed

    Chen, Shaohua; Liu, Chenglan; Peng, Chuyan; Liu, Hongmei; Hu, Meiying; Zhong, Guohua

    2012-01-01

    Intensive use of chlorpyrifos has resulted in its ubiquitous presence as a contaminant in surface streams and soils. It is thus critically essential to develop bioremediation methods to degrade and eliminate this pollutant from environments. We present here that a new fungal strain Hu-01 with high chlorpyrifos-degradation activity was isolated and identified as Cladosporium cladosporioides based on the morphology and 5.8S rDNA gene analysis. Strain Hu-01 utilized 50 mg·L(-1) of chlorpyrifos as the sole carbon of source, and tolerated high concentration of chlorpyrifos up to 500 mg·L(-1). The optimum degradation conditions were determined to be 26.8°C and pH 6.5 based on the response surface methodology (RSM). Under these conditions, strain Hu-01 completely metabolized the supplemented chlorpyrifos (50 mg·L(-1)) within 5 d. During the biodegradation process, transient accumulation of 3,5,6-trichloro-2-pyridinol (TCP) was observed. However, this intermediate product did not accumulate in the medium and disappeared quickly. No persistent accumulative metabolite was detected by gas chromatopraphy-mass spectrometry (GC-MS) analysis at the end of experiment. Furthermore, degradation kinetics of chlorpyrifos and TCP followed the first-order model. Compared to the non-inoculated controls, the half-lives (t(1/2)) of chlorpyrifos and TCP significantly reduced by 688.0 and 986.9 h with the inoculum, respectively. The isolate harbors the metabolic pathway for the complete detoxification of chlorpyrifos and its hydrolysis product TCP, thus suggesting the fungus may be a promising candidate for bioremediation of chlorpyrifos-contaminated water, soil or crop.

  7. Fructose as a novel photosensitizer: Characterization of reactive oxygen species and an application in degradation of diuron and chlorpyrifos.

    PubMed

    Nayak, Shaila; Muniz, Juan; Sales, Christopher M; Tikekar, Rohan V

    2016-02-01

    The objective of this study was to identify reactive oxygen species (ROS) generated from the exposure of fructose solution to the 254 nm ultraviolet (UV) light and evaluate whether fructose can be used as a photosensitizer for accelerated photo-degradation of diuron and chlorpyrifos. We demonstrated that hydrogen peroxide, singlet oxygen ((1)O2) and acidic photolysis products were generated upon UV exposure of fructose. Consistent with these findings, UV induced degradation of chlorpyrifos and diuron was accelerated by the presence of 500 mM fructose. The average first order photo-degradation rate constants in the absence and presence of 500 mM fructose were 0.92 and 2.07 min(-1) respectively for diuron and 0.04 and 0.07 min(-1) for chlorpyrifos. The quantum yields (ɸ) for direct photo-degradation of diuron and chlorpyrifos were 0.003 and 0.001 respectively. In the presence of 500 mM fructose, these values increased to 0.006 and 0.002 respectively. Thus, fructose may be an effective photosensitizer.

  8. MODELED RESIDENTIAL CHLORPYRIFOS EXPOSURE AND DOSE TO CHILDREN VIA DERMAL SURFACE RESIDUE CONTACT AND NON-DIETARY INGESTION

    EPA Science Inventory

    A physically-based stochastic model has been applied to estimate residential chlorpyrifos exposure and dace to children via the non-dietary ingestion and dermal residue contact pathways. Time-location-activity data for 2825 children were sampled from national surveys to generat...

  9. Dietary predictors of young children’s exposures to chlorpyrifos, permethrin, and 2,4-D using urinary biomonitoring

    EPA Science Inventory

    Few data exist on the association between dietary habits and urinary biomarker concentrations of pesticides in children. The objective was to examined the association between the weekly intake frequency of 65 food items and urinary biomarkers of exposure to chlorpyrifos (3,5,6-tr...

  10. EXAMINATION OF THE EFFECTS OF CHLORPYRIFOS ON DEVELOPMENTAL PROCESSES: EVALUATION OF BIOCHEMICAL, MORPHOLOGICAL, AND BEHAVIORAL INDICES OF DEVELOPMENTAL NEUROTOXICITY.

    EPA Science Inventory

    Until recently, the organophosphate pesticide, chlorpyrifos [CPF; O,O'diethyl O-3,5,6-trichloro-2-pyridyl) phosphorothionate] was one of the highest volume use pesticides in a non agricultural setting. The principal reason for restriction of use of this pesticide has been concern...

  11. Pharmacokinetics and effects on serum cholinesterase activities of organophosphorus pesticides acephate and chlorpyrifos in chimeric mice transplanted with human hepatocytes.

    PubMed

    Suemizu, Hiroshi; Sota, Shigeto; Kuronuma, Miyuki; Shimizu, Makiko; Yamazaki, Hiroshi

    2014-11-01

    Organophosphorus pesticides acephate and chlorpyrifos in foods have potential to impact human health. The aim of the current study was to investigate the pharmacokinetics of acephate and chlorpyrifos orally administered at lowest-observed-adverse-effect-level doses in chimeric mice transplanted with human hepatocytes. Absorbed acephate and its metabolite methamidophos were detected in serum from wild type mice and chimeric mice orally administered 150mg/kg. Approximately 70% inhibition of cholinesterase was evident in plasma of chimeric mice with humanized liver (which have higher serum cholinesterase activities than wild type mice) 1day after oral administrations of acephate. Adjusted animal biomonitoring equivalents from chimeric mice studies were scaled to human biomonitoring equivalents using known species allometric scaling factors and in vitro metabolic clearance data with a simple physiologically based pharmacokinetic (PBPK) model. Estimated plasma concentrations of acephate and chlorpyrifos in humans were consistent with reported concentrations. Acephate cleared similarly in humans and chimeric mice but accidental/incidental overdose levels of chlorpyrifos cleared (dependent on liver metabolism) more slowly from plasma in humans than it did in mice. The data presented here illustrate how chimeric mice transplanted with human hepatocytes in combination with a simple PBPK model can assist evaluations of toxicological potential of organophosphorus pesticides.

  12. NEUROBEHAVIORAL EVALUATION OF RATS EXPOSED TO CHLORPYRIFOS VIA CHRONIC DIETARY AND REPEATED HIGH-LEVEL SPIKE EXPOSURE.

    EPA Science Inventory

    This study aimed to model long-term subtoxic human exposure to an organophosphorus pesticide, chlorpyrifos (CPF), and to examine the influence of that exposure on the response to intermittent high-dose acute challenges. Adult Long-Evans male rats were maintained at 350g body wei...

  13. Effects of chlorpyrifos ethyl on acetylcholinesterase activity in climbing perch cultured in rice fields in the Mekong Delta, Vietnam.

    PubMed

    Nguyen, Tam Thanh; Berg, Håkan; Nguyen, Hang Thi Thuy; Nguyen, Cong Van

    2015-07-01

    Climbing perch is commonly harvested in rice fields and associated wetlands in the Mekong Delta. Despite its importance in providing food and income to local households, there is little information how this fish species is affected by the high use of pesticides in rice farming. Organophosphate insecticides, such as chlorpyrifos ethyl, which are highly toxic to aquatic organisms, are commonly used in the Mekong Delta. This study shows that the brain acetylcholinesterase (AChE) activity in climbing perch fingerlings cultured in rice fields, was significantly inhibited by a single application of chlorpyrifos ethyl, at doses commonly applied by rice farmers (0.32-0.64 kg/ha). The water concentration of chlorpyrifos ethyl decreased below the detection level within 3 days, but the inhibition of brain AChE activity remained for more than 12 days. In addition, the chlorpyrifos ethyl treatments had a significant impact on the survival and growth rates of climbing perch fingerlings, which were proportional to the exposure levels. The results indicate that the high use of pesticides among rice farmers in the Mekong Delta could have a negative impact on aquatic organisms and fish yields, with implications for the aquatic biodiversity, local people's livelihoods and the aquaculture industry in the Mekong Delta. PMID:25828891

  14. A sensitive monoclonal antibody-based enzyme-linked immunosorbent assay for chlorpyrifos residue determination in Chinese agricultural smaples

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A monoclonal antibody-based competitive antibody-coated enzyme-linked immunosorbent assay (ELISA) was developed and optimized for determining chlorpyrifos residue in agricultural products. The IC50 and IC10 of this ELISA were 3.3 ng/mL and 0.1 ng/mL respectively. The average recoveries recovery rate...

  15. Safety methods for chlorpyrifos removal from date fruits and its relation with sugars, phenolics and antioxidant capacity of fruits.

    PubMed

    Osman, Khaled A; Al-Humaid, A I; Al-Redhaiman, K N; El-Mergawi, Ragab A

    2014-09-01

    The effectiveness of different postharvest wash treatments at two levels (10 and 20 g/l) for different dipping times was determined to remove chlorpyrifos from date fruits treated at concentration of 2 mg/l. The recovered amount of chlorpyrifos was extracted based on the solid phase extraction (SPE) method and then analyzed by gas chromatography with mass spectrometry (GC-MS). The results demonstrate that the removal of chlorpyrifos increased in the order of acetic acid (AA)> citric acid (CA)> hydrogen peroxide (H2O2)> potassium permanganate (KMnO4)> running water (H2O), and the percent of pesticide residue on date fruits depended on the concentration of tested washing treatments and dipping time without the formation of the toxic by-product, chlorpyrifos-oxon. Kinetic studies revealed that chlorpyrifos was found to be more easily removable from date fruits treated with the tested chemical solutions with t1/2 values of 12-29 min compared with roughly 53 min in case of running water. The impact of these washing treatments on quality of date fruits illustrated that all treatments exerted a little negative effect on total sugars content but H2O2 and KMnO4 at level of 2 % had more drastic effect. Whereas, running water, 10 and 20 g/l CA caused significant increases in total phenolic contents, during all the tested contact times compared with control. Except the insignificant effect of KMnO4 treatments, antioxidant capacity of date fruits tended to increase in all wash treatments, when the contact times were 5 or 15 min. PMID:25190831

  16. Prenatal Dexamethasone Augments the Sex-Selective Developmental Neurotoxicity of Chlorpyrifos: Implications for Vulnerability after Pharmacotherapy for Preterm Labor

    PubMed Central

    Slotkin, Theodore A.; Card, Jennifer; Infante, Alice; Seidler, Frederic J.

    2013-01-01

    Glucocorticoids are routinely given in preterm labor and are also elevated by maternal stress; organophosphate exposures are virtually ubiquitous, so coexposures to these two agents are pervasive. We administered dexamethasone to pregnant rats on gestational days 17–19 at a standard therapeutic dose (0.2 mg/kg); offspring were then given chlorpyrifos on postnatal days 1–4, at a dose (1 mg/kg) that produces barely-detectable (<10%) inhibition of brain cholinesterase activity. We evaluated indices for acetylcholine (ACh) synaptic function throughout adolescence, young adulthood and later adulthood, in brain regions possessing the majority of ACh projections and cell bodies; we measured nicotinic ACh receptor binding, hemicholinium-3 binding to the presynaptic choline transporter and choline acetyltransferase activity, all known targets for the adverse developmental effects of dexamethasone and chlorpyrifos given individually. Dexamethasone did not enhance the systemic toxicity of chlorpyrifos, as evidenced by weight gain and measurements of cholinesterase inhibition during chlorpyrifos treatment. Nevertheless, it enhanced the loss of presynaptic ACh function selectively in females, who ordinarily show sparing of organophosphate developmental neurotoxicity relative to males. Females receiving the combined treatment showed decrements in choline transporter binding and choline acetyltransferase activity that were unique (not found with either treatment alone), as well as additive decrements in nicotinic receptor binding. On the other hand, males given dexamethasone showed no augmentation of the effects of chlorpyrifos. Our findings indicate that prior dexamethasone exposure could create a subpopulation that is especially vulnerable to the adverse effects of organophosphates or other developmental neurotoxicants. PMID:23416428

  17. The expression of proteins involved in digestion and detoxification are regulated in Helicoverpa armigera to cope up with chlorpyrifos insecticide.

    PubMed

    Dawkar, Vishal V; Chikate, Yojana R; More, Tushar H; Gupta, Vidya S; Giri, Ashok P

    2016-02-01

    Helicoverpa armigera is a key pest in many vital crops, which is mainly controlled by chemical strategies. To manage this pest is becoming challenging due to its ability and evolution of resistance against insecticides. Further, its subsequent spread on nonhost plant is remarkable in recent times. Hence, decoding resistance mechanism against phytochemicals and synthetic insecticides is a major challenge. The present work describes that the digestion, defense and immunity related enzymes are associated with chlorpyrifos resistance in H. armigera. Proteomic analysis of H. armigera gut tissue upon feeding on chlorpyrifos containing diet (CH) and artificial diet (AD) using nano-liquid chromatography-mass spectrometry identified upregulated 23-proteins in CH fed larvae. Database searches combined with gene ontology analysis revealed that the identified gut proteins engrossed in digestion, proteins crucial for immunity, adaptive responses to stress, and detoxification. Biochemical and quantitative real-time polymerase chain reaction analysis of candidate proteins indicated that insects were struggling to get nutrients and energy in presence of CH, while at the same time endeavoring to metabolize chlorpyrifos. Moreover, we proposed a potential processing pathway of chlorpyrifos in H. armigera gut by examining the metabolites using gas chromatography-mass spectrometry. H. armigera exhibit a range of intriguing behavioral, morphological adaptations and resistance to insecticides by regulating expression of proteins involved in digestion and detoxification mechanisms to cope up with chlorpyrifos. In these contexts, as gut is a rich repository of biological information; profound analysis of gut tissues can give clues of detoxification and resistance mechanism in insects. PMID:25284010

  18. PON1 status does not influence cholinesterase activity in Egyptian agricultural workers exposed to chlorpyrifos

    SciTech Connect

    Ellison, Corie A.; Crane, Alice L.; Bonner, Matthew R.; Knaak, James B.; Browne, Richard W.; Lein, Pamela J.; Olson, James R.

    2012-12-15

    Animal studies have shown that paraoxonase 1 (PON1) genotype can influence susceptibility to the organophosphorus pesticide chlorpyrifos (CPF). However, Monte Carlo analysis suggests that PON1 genotype may not affect CPF-related toxicity at low exposure conditions in humans. The current study sought to determine the influence of PON1 genotype on the activity of blood cholinesterase as well as the effect of CPF exposure on serum PON1 in workers occupationally exposed to CPF. Saliva, blood and urine were collected from agricultural workers (n = 120) from Egypt's Menoufia Governorate to determine PON1 genotype, blood cholinesterase activity, serum PON1 activity towards chlorpyrifos-oxon (CPOase) and paraoxon (POase), and urinary levels of the CPF metabolite 3,5,6-trichloro-2-pyridinol (TCPy). The PON1 55 (P ≤ 0.05) but not the PON1 192 genotype had a significant effect on CPOase activity. However, both the PON1 55 (P ≤ 0.05) and PON1 192 (P ≤ 0.001) genotypes had a significant effect on POase activity. Workers had significantly inhibited AChE and BuChE after CPF application; however, neither CPOase activity nor POase activity was associated with ChE depression when adjusted for CPF exposure (as determined by urinary TCPy levels) and stratified by PON1 genotype. CPOase and POase activity were also generally unaffected by CPF exposure although there were alterations in activity within specific genotype groups. Together, these results suggest that workers retained the capacity to detoxify chlorpyrifos-oxon under the exposure conditions experienced by this study population regardless of PON1 genotype and activity and that effects of CPF exposure on PON1 activity are minimal. -- Highlights: ► CPF exposure resulted in an increase in TCPy and decreases in BuChE and AChE. ► CPOase activity decreased in subjects with the PON1 55LM and PON1 55 MM genotypes. ► Neither PON1 genotype nor CPOase activity had an effect on BuChE or AChE inhibition.

  19. [Intermediate phenotype of schizophrenia].

    PubMed

    Hashimoto, Ryota

    2013-04-01

    Genes are major contributors to schizophrenia. The intermediate phenotype concept represents a strategy for identifying risk genes for schizophrenia and for characterizing the neural systems affected by risk gene variants to elucidate quantitative, mechanistic aspects of brain function implicated in schizophrenia. Intermediate phenotypes are defined by being heritable, being able to measure quantitatively; being related to the disorder and its symptoms in the general population; being stable over time; showing increased expression in unaffected relatives of probands; and cosegregation with the disorder in families. Intermediate phenotypes in schizophrenia are neurocognition, neuroimaging, neurophysiology, etc. In this review, we present concept, recent work, and future perspective of intermediate phenotype.

  20. CHRONIC DIETARY EXPOSURE WITH INTERMITTENT SPIKE DOSES OF CHLORPYRIFOS FALLS TO ALTER SOMATOSENSORY EVOKED POTENTIALS, COMPOUND NERVE ACTION POTENTIALS, OR NERVE CONDUCTION VELOCITY IN RATS.

    EPA Science Inventory

    Human exposure to pesticides is often characterized by chronic low level exposure with intermittent spiked higher exposures. Cholinergic transmission is involved in sensory modulation in the cortex and cerebellum, and therefore may be altered following chlorpyrifos (CPF) exposure...

  1. Dissipation of chlorothalonil, chlorpyrifos, and profenofos in a Malaysian agricultural soil: a comparison between the field experiment and simulation by the PERSIST model.

    PubMed

    Ismail, B S; Ngan, C K

    2005-01-01

    A comparison of dissipation of chlorothalonil, chlorpyrifos, and profenofos in a Malaysian agricultural soil between the field experiment and simulation by the PERSIST model was studied. A plot of sweet pea (Pisum sativum) from a farm in the Cameron Highlands was selected for the field experiment. The plot was treated with chlorothalonil, chlorpyrifos, and profenofos. Core soil collection was conducted according to the sampling schedule. Residues of the three pesticides were analyzed in the laboratory. Simulations of the three pesticides' persistency were also conducted using a computer-run software PERSIST. Generally, predicted data obtained using PERSIST were found to be high for the three pesticides except for one field measurement of chlorpyrifos. The predicted data for profenofos, which is the most mobile of the three pesticides tested, was not well matched with the observed data compared to chlorothalonil and chlorpyrifos. PMID:15825685

  2. Differential effects of herbicides atrazine and fenoxaprop-ethyl, and insecticides diazinon and malathion, on viability and maturation of porcine oocytes in vitro.

    PubMed

    Casas, Eduardo; Bonilla, Edmundo; Ducolomb, Yvonne; Betancourt, Miguel

    2010-02-01

    Exposure to pesticides may be a major cause of reproductive dysfunction in humans and animals. Atrazine and fenoxaprop-ethyl, widely used herbicides, and malathion and diazinon, organophosphate insecticides, are considered only slightly toxic to vertebrates; however, there is evidence of greater effects on reproductive function. The aim of this study was to evaluate the effect of these pesticides on oocyte viability and in vitro maturation. Gametes were matured in increasing concentrations of the pesticides and then stained with MTT to evaluate viability and bisbenzimide to assess the maturation stage, in the same oocyte. Atrazine had no effect on viability but maturation was significantly reduced, while fenoxaprop-ethyl affected both parameters. The insecticides affected viability and maturation but to a different degree. The four pesticides showed a more pronounced effect on maturation than on viability, due to a blockage at germinal vesicle stage.

  3. Differential effects of herbicides atrazine and fenoxaprop-ethyl, and insecticides diazinon and malathion, on viability and maturation of porcine oocytes in vitro.

    PubMed

    Casas, Eduardo; Bonilla, Edmundo; Ducolomb, Yvonne; Betancourt, Miguel

    2010-02-01

    Exposure to pesticides may be a major cause of reproductive dysfunction in humans and animals. Atrazine and fenoxaprop-ethyl, widely used herbicides, and malathion and diazinon, organophosphate insecticides, are considered only slightly toxic to vertebrates; however, there is evidence of greater effects on reproductive function. The aim of this study was to evaluate the effect of these pesticides on oocyte viability and in vitro maturation. Gametes were matured in increasing concentrations of the pesticides and then stained with MTT to evaluate viability and bisbenzimide to assess the maturation stage, in the same oocyte. Atrazine had no effect on viability but maturation was significantly reduced, while fenoxaprop-ethyl affected both parameters. The insecticides affected viability and maturation but to a different degree. The four pesticides showed a more pronounced effect on maturation than on viability, due to a blockage at germinal vesicle stage. PMID:19747538

  4. Ultrasond-assisted synthesis of Fe3O4/SiO2 core/shell with enhanced adsorption capacity for diazinon removal

    NASA Astrophysics Data System (ADS)

    Farmany, Abbas; Mortazavi, Seyede Shima; Mahdavi, Hossein

    2016-10-01

    Fe3O4/SiO2 core/shell nanocrystals were synthesized by ultrasond-assisted procedure. The core/shell nanocrystals were characterized using XRD, FT-IR spectroscopy, SEM and BET. The BET analysis confirmed that iron oxide nanocrystal with the surface area of 208.0 m2/g can be used as an excellent adsorbent for organic and inorganic pollutants. The core/shell nanocrystal was used as an adsorbent for removal of insecticide O,O-diethyl-O[2-isopropyl-6-methylpyridimidinyl] phosphorothioate (diazinon). In continue the influence of different parameters such as pH, adsorbent dosage and shaking time on the adsorption capacity were studied. The experimental data were fitted well with the pseudo-second-order kinetic model (R2=0.9706). The adsorption isotherm was described well by Langmuir isotherm.

  5. Chronic exposure to chlorpyrifos reveals two modes of action in the springtail Folsomia candida.

    PubMed

    Jager, Tjalling; Crommentuijn, Trudie; van Gestel, Cornelis A M; Kooijman, Sebastiaan A L M

    2007-01-01

    Organophosphates are popular insecticides, but relatively little is known about their chronic effects on ecologically relevant endpoints. In this paper, we examine a life-cycle experiment with the springtail Folsomia candida, exposed via food to chlorpyrifos (CPF). The results for all endpoints (survival, growth and reproduction) were analyzed using the DEBtox model. Growth was unaffected by CPF, even at concentrations causing severe effects on survival and reproduction. Model analysis suggests that CPF directly affects the process of egg production. For the short-term response (45 days), this single mode of action accurately agreed with the data. However, the full data set (120 days) revealed a dose-related decrease in reproduction at low concentrations after prolonged exposure, not covered by the same mechanism. It appears that CPF interacts with senescence by increasing oxidative damage. This assumption fits the data well, but has little consequences for the predicted response at the population level. PMID:16762466

  6. Biodegradation of chlorpyrifos by Pseudomonas sp. in a continuous packed bed bioreactor.

    PubMed

    Yadav, Maya; Srivastva, Navnita; Singh, Ram Sharan; Upadhyay, Siddh Nath; Dubey, Suresh Kumar

    2014-08-01

    Biodegradation of chlorpyrifos (CP) by Pseudomonas (Iso 1) sp. was investigated in batch as well as continuous bioreactors packed with polyurethane foam pieces. The optimum process parameters for the maximum removal of CP, determined through batch experiments, were found to be: inoculum level, 300×10(6)CfumL(-1); CP concentration, 500mgL(-1); pH 7.5; temperature, 37°C and DO, 5.5mgL(-1). The continuous packed bed bioreactor was operated at various flow rates (10-40mLh(-1)) under the optimum conditions. The steady state CP removal efficiency of more than 91% was observed up to the inlet load of 300mgL(-1)d(-1). The bioreactor was sensitive to flow fluctuations but was able to recover its performance quickly and exhibited the normal plug-flow behavior. Accumulation of TCP (3,5,6-trichloro-2-pyridinol) affected the reactor performance.

  7. Efficacy of Aspergillus sp. for degradation of chlorpyrifos in batch and continuous aerated packed bed bioreactors.

    PubMed

    Yadav, Maya; Srivastva, Navnita; Shukla, Awadhesh Kumar; Singh, Ram Sharan; Upadhyay, Siddh Nath; Dubey, Suresh Kumar

    2015-01-01

    Aerobic biodegradation of chlorpyrifos (CP) by Aspergillus sp. was investigated in batch and continuous packed bed bioreactors. The optimal process parameters for achieving the maximum removal efficiency (RE), determined using a batch bioreactor packed with polyurethane foam pieces, were inoculum level: 2.5 mg (wet weight) mL(-1), pH 7.0, temperature 28 °C, DO 5.8 mg L(-1), and CP concentration 300 mg L(-1). The continuous packed bed bioreactor was operated at flow rates ranging from 10 to 40 mL h(-1) while keeping other parameters at their optimal level. Steady-state CP removal efficiencies greater than 85 % were obtained up to the inlet loading of 180 mg L(-1) d(-1). The continuous bioreactor behaved as a plug flow unit and was able to stabilize quickly after perturbation in the inlet loading.

  8. Impact of Location, Cropping History, Tillage, and Chlorpyrifos on Soil Arthropods in Peanut.

    PubMed

    Cardoza, Yasmin J; Drake, Wendy L; Jordan, David L; Schroeder-Moreno, Michelle S; Arellano, Consuelo; Brandenburg, Rick L

    2015-08-01

    Demand for agricultural production systems that are both economically viable and environmentally conscious continues to increase. In recent years, reduced tillage systems, and grass and pasture rotations have been investigated to help maintain or improve soil quality, increase crop yield, and decrease labor requirements for production. However, documentation of the effects of reduced tillage, fescue rotation systems as well as other management practices, including pesticides, on pest damage and soil arthropod activity in peanut production for the Mid-Atlantic US region is still limited. Therefore, this project was implemented to assess impacts of fescue-based rotation systems on pests and other soil organisms when compared with cash crop rotation systems over four locations in eastern North Carolina. In addition, the effects of tillage (strip vs. conventional) and soil chlorpyrifos application on pod damage and soil-dwelling organisms were also evaluated. Soil arthropod populations were assessed by deploying pitfall traps containing 50% ethanol in each of the sampled plots. Results from the present study provide evidence that location significantly impacts pest damage and soil arthropod diversity in peanut fields. Cropping history also influenced arthropod diversity, with higher diversity in fescue compared with cash crop fields. Corn rootworm damage to pods was higher at one of our locations (Rocky Mount) compared with all others. Cropping history (fescue vs. cash crop) did not have an effect on rootworm damage, but increased numbers of hymenopterans, acarina, heteropterans, and collembolans in fescue compared with cash crop fields. Interestingly, there was an overall tendency for higher number of soil arthropods in traps placed in chlorpyrifos-treated plots compared with nontreated controls. PMID:26314040

  9. Rapid detection of chlorpyrifos pesticide residue concentration in agro-product using Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Dhakal, Sagar; Peng, Yankun; Li, Yongyu; Chao, Kuanglin; Qin, Jianwei; Zhang, Leilei; Xu, Tianfeng

    2014-05-01

    Different chemicals are sprayed in fruits and vegetables before and after harvest for better yield and longer shelf-life of crops. Cases of pesticide poisoning to human health are regularly reported due to excessive application of such chemicals for greater economic benefit. Different analytical technologies exist to detect trace amount of pesticides in fruits and vegetables, but are expensive, sample destructive, and require longer processing time. This study explores the application of Raman spectroscopy for rapid and non-destructive detection of pesticide residue in agricultural products. Raman spectroscopy with laser module of 785 nm was used to collect Raman spectral information from the surface of Gala apples contaminated with different concentrations of commercially available organophosphorous (48% chlorpyrifos) pesticide. Apples within 15 days of harvest from same orchard were used in this study. The Raman spectral signal was processed by Savitzky-Golay (SG) filter for noise removal, Multiplicative Scatter Correction (MSC) for drift removal and finally polynomial fitting was used to eliminate the fluorescence background. The Raman spectral peak at 677 cm-1 was recognized as Raman fingerprint of chlorpyrifos. Presence of Raman peak at 677 cm-1 after fluorescence background removal was used to develop classification model (presence and absence of pesticide). The peak intensity was correlated with actual pesticide concentration obtained using Gas Chromatography and MLR prediction model was developed with correlation coefficient of calibration and validation of 0.86 and 0.81 respectively. Result shows that Raman spectroscopy is a promising tool for rapid, real-time and non-destructive detection of pesticide residue in agro-products.

  10. Impact of Location, Cropping History, Tillage, and Chlorpyrifos on Soil Arthropods in Peanut.

    PubMed

    Cardoza, Yasmin J; Drake, Wendy L; Jordan, David L; Schroeder-Moreno, Michelle S; Arellano, Consuelo; Brandenburg, Rick L

    2015-08-01

    Demand for agricultural production systems that are both economically viable and environmentally conscious continues to increase. In recent years, reduced tillage systems, and grass and pasture rotations have been investigated to help maintain or improve soil quality, increase crop yield, and decrease labor requirements for production. However, documentation of the effects of reduced tillage, fescue rotation systems as well as other management practices, including pesticides, on pest damage and soil arthropod activity in peanut production for the Mid-Atlantic US region is still limited. Therefore, this project was implemented to assess impacts of fescue-based rotation systems on pests and other soil organisms when compared with cash crop rotation systems over four locations in eastern North Carolina. In addition, the effects of tillage (strip vs. conventional) and soil chlorpyrifos application on pod damage and soil-dwelling organisms were also evaluated. Soil arthropod populations were assessed by deploying pitfall traps containing 50% ethanol in each of the sampled plots. Results from the present study provide evidence that location significantly impacts pest damage and soil arthropod diversity in peanut fields. Cropping history also influenced arthropod diversity, with higher diversity in fescue compared with cash crop fields. Corn rootworm damage to pods was higher at one of our locations (Rocky Mount) compared with all others. Cropping history (fescue vs. cash crop) did not have an effect on rootworm damage, but increased numbers of hymenopterans, acarina, heteropterans, and collembolans in fescue compared with cash crop fields. Interestingly, there was an overall tendency for higher number of soil arthropods in traps placed in chlorpyrifos-treated plots compared with nontreated controls.

  11. Integrating ecosystem services into risk management decisions: case study with Spanish citrus and the insecticide chlorpyrifos.

    PubMed

    Deacon, Samantha; Norman, Steve; Nicolette, Joseph; Reub, Gregory; Greene, Gretchen; Osborn, Rachel; Andrews, Paul

    2015-02-01

    The European regulatory system for the approval of pesticides includes a thorough evaluation of risks to the environment and is designed to be protective of ecosystems. However, a decision to ban an agrochemical could also potentially have a negative impact on the value of ecosystem services, if resulting changes in crop management are damaging to ecosystems or result in negative socio-economic impacts. To support regulatory decision-making, consideration of ecosystem services to identify best environmental management options could be a way forward. There is generally a growing trend for the consideration of ecosystem services in decision making. Ecosystems provide the conditions for growing food, regulate water and provide wildlife habitats; these, amongst others, are known as ecosystem services. The objectives of this case study were to bring a holistic approach to decision making by valuing the environmental, social and economic benefits derived from the use of chlorpyrifos in Valencian citrus production. Spanish growers harvest between 5 and 6 milliont of citrus annually, worth an estimated €5 to 7 billion in food markets throughout Europe. The approach highlighted the potential for unintended negative consequences of regulatory decisions if the full context is not considered. In this study, rather than a regulatory restriction, the best option was the continued use of chlorpyrifos together with vegetated conservation patches as refuges for non-target insects. The conservation patches offset potential insecticidal impacts to insects whilst maintaining citrus production, farm income and the amenity value of the citrus landscape of Valencia. This was an initial proof-of-concept study and illustrates the importance of a wider perspective; other cases may have different outcomes depending on policies, the pesticide, crop scenarios, farm economics and the region.

  12. Effects of Nicotine Exposure on In Vitro Metabolism of Chlorpyrifos in Male Sprague-Dawley Rats

    SciTech Connect

    Lee, Sookwang; Busby, Andrea L.; Timchalk, Charles; Poet, Torka S.

    2009-01-30

    Chlorpyrifos (CPF) is a common organophosphate (OP) insecticide which is metabolized by CYP450s to the neurotoxic metabolite, chlorpyrifos-oxon (CPF-oxon) and a non-toxic metabolite, 3,5,6-trichloro-2-pyridinol (TCP). The objective of this study was to quantify the effect of repeated in vivo nicotine exposures on CPF in vitro metabolism and marker substrate activities in rats. Male Sprague-Dawley rats were dosed subcutaneously with 1 mg nicotine/kg/, for up to 10 days. Animals showed signs of cholinergic crisis after the initial nicotine doses, but exhibited adaptation after a couple days of treatment. Rats were sacrificed on selected days 4 or 24 hr after the last nicotine-treatment. While CYP450 reduced CO spectra were not different across the treatments, the single nicotine dose group showed a 2-fold increase in CYP2E1 marker substrate (p-nitrophenol) activity 24 hr after a single nicotine treatment compared to saline controls. Conversely, repeated nicotine treatments resulted in decreased EROD marker substrate activity 4 hr after the 7th day of treatment. CPF-oxon Vmax and Km did not show significant changes across the different nicotine treatment groups. The Vmax describing the metabolism of CPF to TCP was increased on all groups (days 1, 7, and 10) 24 hr after nicotine treatment but were unchanged 4 hr after nicotine treatment. Results of this in vitro study suggest that repeated nicotine exposure (i.e., from smoking) may result in altered metabolism of CPF. Future in vivo experiments based on these results will be conducted to ascertain the impact of in vivo nicotine exposures on CPF metabolism in rats.

  13. Evaluation of acute sensory--motor effects and test sensitivity using termiticide workers exposed to chlorpyrifos.

    PubMed

    Dick, R B; Steenland, K; Krieg, E F; Hines, C J

    2001-01-01

    Sensory and motor testing was performed on a group of termiticide workers primarily using chlorpyrifos-containing products to evaluate both the acute effects from current exposure and sensitivity of the measures to detect effects. The study group comprised 106 applicators and 52 nonexposed participants. Current exposure was measured by urinary concentrations of 3,5,6-trichloro-2-pyridinol (TCP) collected the morning of testing. The mean TCP value for the 106 applicators was 200 microg/g creatinine. Participants received 4--5 h of testing and were evaluated using a sensory--motor test battery recommended by a National Institute for Occupational Safety and Health (NIOSH)-sponsored advisory panel to be appropriate for testing effects from pesticide exposures. Measurements testing olfactory dysfunction, visual acuity, contrast sensitivity, color vision, vibrotactile sensitivity, tremor, manual dexterity, eye--hand coordination, and postural stability were analyzed. Study results indicated limited acute effects from exposure to chlorpyrifos using urinary TCP as a measure of current exposure. The effects occurred primarily on measures of postural sway in the eyes closed and soft-surface conditions, which suggests a possible subclinical effect involving the proprioceptive and vestibular systems. Several other tests of motor and sensory functions did not show any evidence of acute exposure effects, although statistically significant effects of urinary TCP on the Lanthony color vision test scores and one contrast sensitivity test score were found. The visual measures, however, were not significant when a step-down Bonferroni correction was applied. Information also is presented on the sensitivity of the measures to detect effects in an occupationally exposed population using standard error of the parameter estimates. PMID:11485841

  14. Effects of chlorpyrifos on in vitro sex steroid production and thyroid follicular development in adult and larval Lake Sturgeon, Acipenser fulvescens.

    PubMed

    Brandt, Catherine; Burnett, Duncan C; Arcinas, Liane; Palace, Vince; Gary Anderson, W

    2015-08-01

    Chlorpyrifos is a widely used organophosphate pesticide that has previously been shown to enter waterways in biologically relevant concentrations and has the potential to disrupt both thyroid hormone and sex steroid biosynthesis in vertebrates. Because gonadal maturation and larval development in Lake Sturgeon, Acipenser fulvescens, potentially coincide with the application of chlorpyrifos we examined the effects of chlorpyrifos on both thyroid follicular development in larval Lake Sturgeon, and sex hormone synthesis in adult Lake Sturgeon. For the first time, the present study reports steroidogenesis from testicular and ovarian tissue in Lake Sturgeon using an established in vitro bioassay. Furthermore, incubating gonad tissue with 5, 500 or 2000ngmL(-1) chlorpyrifos revealed an inhibitory effect on testosterone synthesis in both testicular (control, 40.29pgmg(-1) tissue wet weight(-1)h(-1) compared to experimental, 21.84pgmg(-1) tissue wet weight(-1)h(-1)) and ovarian (control, 33.83pgmg(-1) tissue wet weight(-1)h(-1) compared to experimental, 15.19pgmg(-1) tissue wet weight(-1)h(-1)) tissue. In a second series of experiments, larval Lake Sturgeon were exposed to equivalent concentrations of chlorpyrifos as above for 10days (d) between hatch and the onset of exogenous feeding. Larvae from each treatment group were raised until 67days post hatch (dph) and growth rates were compared alongside key indicators of thyroid follicle growth. Chlorpyrifos treatment had no effect on the measured indicators of thyroid follicular development.

  15. Resistance Mechanisms to Chlorpyrifos and F392W Mutation Frequencies in the Acetylcholine Esterase Ace1 Allele of Field Populations of the Tobacco Whitefly, Bemisia tabaci in China

    PubMed Central

    Zhang, Ning-ning; Liu, Cai-feng; Yang, Fang; Dong, Shuang-lin; Han, Zhao-jun

    2012-01-01

    The tobacco whitefly B-biotype Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) is a worldwide pest of many crops. In China, chlorpyrifos has been used to control this insect for many years and is still being used despite the fact that some resistance has been reported. To combat resistance and maintain good control efficiency of chlorpyrifos, it is essential to understand resistance mechanisms. A chlorpyrifos resistant tobacco whitefly strain (NJ-R) and a susceptible strain (NJ-S) were derived from a field-collected population in Nanjing, China, and the resistance mechanisms were investigated. More than 30-fold resistance was achieved after selected by chlorpyrifos for 13 generations in the laboratory. However, the resistance dropped significantly to about 18-fold in only 4 generations without selection pressure. Biochemical assays indicated that increased esterase activity was responsible for this resistance, while acetylcholine esterase, glutathione S-transferase, and microsomal-O-demethylase played little or no role. F392W mutations in acel were prevalent in NJ-S and NJ-R strains and 6 field-collected populations of both B and Q-biotype from locations that cover a wide geographical area of China. These findings provide important information about tobacco whitefly chlorpyrifos resistance mechanisms and guidance to combat resistance and optimize use patterns of chlorpyrifos and other organophosphate and carbamate insecticides. PMID:22954331

  16. Individual variability in esterase activity and CYP1A levels in Chinook salmon (Oncorhynchus tshawytscha) exposed to esfenvalerate and chlorpyrifos

    USGS Publications Warehouse

    Wheelock, C.E.; Eder, K.J.; Werner, I.; Huang, H.; Jones, P.D.; Brammell, B.F.; Elskus, A.A.; Hammock, B.D.

    2005-01-01

    Acetylcholinesterase (AChE) activity has traditionally been monitored as a biomarker of organophosphate (OP) and/or carbamate exposure. However, AChE activity may not be the most sensitive endpoint for these agrochemicals, because OPs can cause adverse physiological effects at concentrations that do not affect AChE activity. Carboxylesterases are a related family of enzymes that have higher affinity than AChE for some OPs and carbamates and may be more sensitive indicators of environmental exposure to these pesticides. In this study, carboxylesterase and AChE activity, cytochrome P4501A (CYP1A) protein levels, and mortality were measured in individual juvenile Chinook salmon (Oncorhynchus tshawytscha) following exposure to an OP (chlorpyrifos) and a pyrethroid (esfenvalerate). As expected, high doses of chlorpyrifos and esfenvalerate were acutely toxic, with nominal concentrations (100 and 1 ??g/l, respectively) causing 100% mortality within 96 h. Exposure to chlorpyrifos at a high dose (7.3 ??g/l), but not a low dose (1.2 ??g/l), significantly inhibited AChE activity in both brain and muscle tissue (85% and 92% inhibition, respectively), while esfenvalerate exposure had no effect. In contrast, liver carboxylesterase activity was significantly inhibited at both the low and high chlorpyrifos dose exposure (56% and 79% inhibition, respectively), while esfenvalerate exposure still had little effect. The inhibition of carboxylesterase activity at levels of chlorpyrifos that did not affect AChE activity suggests that some salmon carboxylesterase isozymes may be more sensitive than AChE to inhibition by OPs. CYP1A protein levels were ???30% suppressed by chlorpyrifos exposure at the high dose, but esfenvalerate had no effect. Three teleost species, Chinook salmon, medaka (Oryzias latipes) and Sacramento splittail (Pogonichthys macrolepidotus), were examined for their ability to hydrolyze a series of pyrethroid surrogate substrates and in all cases hydrolysis activity was

  17. Individual variability in esterase activity and CYP1A levels in Chinook salmon (Oncorhynchus tshawytscha) exposed to esfenvalerate and chlorpyrifos

    PubMed Central

    Wheelock, Craig E.; Eder, Kai J.; Werner, Inge; Huang, Huazhang; Jones, Paul D.; Brammell, Benjamin F.; Elskus, Adria A.; Hammock, Bruce D.

    2006-01-01

    Acetylcholinesterase (AChE) activity has traditionally been monitored as a biomarker of organophosphate (OP) and/or carbamate exposure. However, AChE activity may not be the most sensitive endpoint for these agrochemicals, because OPs can cause adverse physiological effects at concentrations that do not affect AChE activity. Carboxylesterases are a related family of enzymes that have higher affinity than AChE for some OPs and carbamates and may be more sensitive indicators of environmental exposure to these pesticides. In this study, carboxylesterase and AChE activity, cytochrome P4501A (CYP1A) protein levels, and mortality were measured in individual juvenile Chinook salmon (Oncorhynchus tshawytscha) following exposure to an OP (chlorpyrifos) and a pyrethroid (esfenvalerate). As expected, high doses of chlorpyrifos and esfenvalerate were acutely toxic, with nominal concentrations (100 and 1 μg/l, respectively) causing 100% mortality within 96 h. Exposure to chlorpyrifos at a high dose (7.3 μg/l), but not a low dose (1.2 μg/l), significantly inhibited AChE activity in both brain and muscle tissue (85% and 92% inhibition, respectively), while esfenvalerate exposure had no effect. In contrast, liver carboxylesterase activity was significantly inhibited at both the low and high chlorpyrifos dose exposure (56% and 79% inhibition, respectively), while esfenvalerate exposure still had little effect. The inhibition of carboxylesterase activity at levels of chlorpyrifos that did not affect AChE activity suggests that some salmon carboxylesterase isozymes may be more sensitive than AChE to inhibition by OPs. CYP1A protein levels were ∼30% suppressed by chlorpyrifos exposure at the high dose, but esfenvalerate had no effect. Three teleost species, Chinook salmon, medaka (Oryzias latipes) and Sacramento splittail (Pogonichthys macrolepidotus), were examined for their ability to hydrolyze a series of pyrethroid surrogate substrates and in all cases hydrolysis activity was

  18. Phenotype definition in epilepsy.

    PubMed

    Winawer, Melodie R

    2006-05-01

    Phenotype definition consists of the use of epidemiologic, biological, molecular, or computational methods to systematically select features of a disorder that might result from distinct genetic influences. By carefully defining the target phenotype, or dividing the sample by phenotypic characteristics, we can hope to narrow the range of genes that influence risk for the trait in the study population, thereby increasing the likelihood of finding them. In this article, fundamental issues that arise in phenotyping in epilepsy and other disorders are reviewed, and factors complicating genotype-phenotype correlation are discussed. Methods of data collection, analysis, and interpretation are addressed, focusing on epidemiologic studies. With this foundation in place, the epilepsy subtypes and clinical features that appear to have a genetic basis are described, and the epidemiologic studies that have provided evidence for the heritability of these phenotypic characteristics, supporting their use in future genetic investigations, are reviewed. Finally, several molecular approaches to phenotype definition are discussed, in which the molecular defect, rather than the clinical phenotype, is used as a starting point.

  19. Application of chemometric analysis based on physicochemical and chromatographic data for the differentiation origin of plant protection products containing chlorpyrifos.

    PubMed

    Miszczyk, Marek; Płonka, Marlena; Bober, Katarzyna; Dołowy, Małgorzata; Pyka, Alina; Pszczolińska, Klaudia

    2015-01-01

    The aim of this study was to investigate the similarities and dissimilarities between the pesticide samples in form of emulsifiable concentrates (EC) formulation containing chlorpyrifos as active ingredient coming from different sources (i.e., shops and wholesales) and also belonging to various series. The results obtained by the Headspace Gas Chromatography-Mass Spectrometry method and also some selected physicochemical properties of examined pesticides including pH, density, stability, active ingredient and water content in pesticides tested were compared using two chemometric methods. Applicability of simple cluster analysis and also principal component analysis of obtained data in differentiation of examined plant protection products coming from different sources was confirmed. It would be advantageous in the routine control of originality and also in the detection of counterfeit pesticides, respectively, among commercially available pesticides containing chlorpyrifos as an active ingredient.

  20. Avoidance behaviour of Eisenia fetida to carbofuran, chlorpyrifos, mancozeb and metamidophos in natural soils from the highlands of Colombia.

    PubMed

    García-Santos, Glenda; Keller-Forrer, Karin

    2011-07-01

    Earthworm avoidance behaviour test is an important screening tool in soil eco-toxicology. This test has been developed and validated under North American and European conditions. However, little research has been performed on the avoidance test in the tropics. This work demonstrates the potential suitability of the avoidance behaviour test as screening method in the highlands of Colombia using Eisenia fetida as the bio-indicator species on contaminated soils with carbofuran and chlorpyrifos. Though for the two active ingredients 100% avoidance was not reached, a curve with six meaningful concentrations is provided. No significant avoidance behaviour trend was found for mancozeb and methamidophos. Tests were conducted in the field yielded similar results to the tests carried out in the laboratory for chlorpyrifos and mancozeb. However, for the case of carbofuran and methamidophos, differences of more than double in avoidance were obtained. Divergence might be explained by soil and temperature conditions.

  1. The Drosophila phenotype ontology

    PubMed Central

    2013-01-01

    Background Phenotype ontologies are queryable classifications of phenotypes. They provide a widely-used means for annotating phenotypes in a form that is human-readable, programatically accessible and that can be used to group annotations in biologically meaningful ways. Accurate manual annotation requires clear textual definitions for terms. Accurate grouping and fruitful programatic usage require high-quality formal definitions that can be used to automate classification. The Drosophila phenotype ontology (DPO) has been used to annotate over 159,000 phenotypes in FlyBase to date, but until recently lacked textual or formal definitions. Results We have composed textual definitions for all DPO terms and formal definitions for 77% of them. Formal definitions reference terms from a range of widely-used ontologies including the Phenotype and Trait Ontology (PATO), the Gene Ontology (GO) and the Cell Ontology (CL). We also describe a generally applicable system, devised for the DPO, for recording and reasoning about the timing of death in populations. As a result of the new formalisations, 85% of classifications in the DPO are now inferred rather than asserted, with much of this classification leveraging the structure of the GO. This work has significantly improved the accuracy and completeness of classification and made further development of the DPO more sustainable. Conclusions The DPO provides a set of well-defined terms for annotating Drosophila phenotypes and for grouping and querying the resulting annotation sets in biologically meaningful ways. Such queries have already resulted in successful function predictions from phenotype annotation. Moreover, such formalisations make extended queries possible, including cross-species queries via the external ontologies used in formal definitions. The DPO is openly available under an open source license in both OBO and OWL formats. There is good potential for it to be used more broadly by the Drosophila

  2. A new early life-stage toxicity test using the California grunion (Leuresthes tenuis) and results with chlorpyrifos.

    PubMed

    Goodman, L R; Hansen, D J; Cripe, G M; Middaugh, D P; Moore, J C

    1985-08-01

    California grunion were continuously exposed as embryos and fry to technical chlorpyrifos in two toxicity tests conducted in the same exposure apparatus. The first test, a 35-day early life-stage (ELS) test, began with approximately 2.5-day-old embryos that were exposed in flow-through aquaria in darkness until hatching was stimulated on Day 9 of exposure. The second toxicity test, a fry test, began with newly hatched fry and lasted 26 days. Test water temperature ranged from 23 to 26 degrees C and salinity from 24.5 to 34.0%. Results of the two tests were similar, indicating that exposure of embryos added little to the overall toxicity of chlorpyrifos to grunions. Percentage hatch of embryos was unaffected by the chlorpyrifos concentrations tested. Fry survival was apparently reduced in nominal concentrations greater than or equal to 1.0 micrograms/liter in both tests, but significantly so in concentrations greater than or equal to 1.0 micrograms/liter in the ELS test and greater than or equal to 2.0 micrograms/liter in the fry test. When compared with carrier controls, mean fish weights were significantly reduced in nominal chlorpyrifos concentrations greater than or equal to 0.5 micrograms/liter in the ELS test and greater than or equal to 1.0 micrograms/liter in the fry exposure. Mean bioconcentration factors were 770X for fish that survived the ELS test and 190X for those that survived the fry test. Results demonstrate the practicality of conducting ELS tests for the first time with a marine fish from the Pacific coastal waters of the United States. PMID:2411496

  3. Comparative response of nestling European starlings and red-winged blackbirds to an oral administration of either dimethoate or chlorpyrifos.

    PubMed

    Meyers, S M; Marden, B T; Bennett, R S; Bentley, R

    1992-07-01

    Red-winged blackbird (Agelaius phoeniceus; blackbird) and European starling (Sturnus vulgaris; starling) nestlings were dosed with either 2.0 mg/kg body mass chlorpyrifos, 50.0 mg/kg body mass dimethoate, or a propylene glycol carrier in situ. Four growth measurements (body mass, culmen, tarsus, wing) were recorded from nestlings to determine if these organophosphorus compounds caused perturbations in development at sublethal concentrations. Blackbird nestlings were more sensitive to chlorpyrifos than starling nestlings were more sensitive to dimethoate than blackbird nestlings. This was in contrast to reported adult LD50 values where the reverse was true. Blackbird nestlings were more tolerant of a substantially higher concentration of dimethoate than the adult LD50. The sensitivity of starling nestlings to dimethoate was similar to adults. In contrast, juveniles of both species were more sensitive to chlorpyrifos than adults. After the initial 24 hr, surviving nestlings dosed with either chemical recovered and continued their development. Exposure to dimethoate caused significant depression in starling body mass during the initial 24 hr period. Survivors obtain body mass equal to controls within 48 hr post dosing. The research presented here demonstrates that the simple supposition that passerine nestlings are typically more sensitive to toxins than adults does not always hold true. It also indicates that sensitivity relationships among adults do not necessarily apply to their nestlings.

  4. Synergistic effects caused by atrazine and terbuthylazine on chlorpyrifos toxicity to early-life stages of the zebrafish Danio rerio.

    PubMed

    Pérez, Joanne; Domingues, Inês; Monteiro, Marta; Soares, Amadeu M V M; Loureiro, Susana

    2013-07-01

    This study examined the effects of three widely used pesticides that have been previously detected in aquatic systems neighbouring agricultural fields on the early-life stages of the zebrafish Danio rerio. Tests involving single exposures and binary combinations of the s-triazine herbicides (atrazine and terbuthylazine) and the organophosphate insecticide chlorpyrifos were performed. Several endpoints, such as swimming behaviour, morphological abnormalities and mortality, were studied. In addition, the inhibition of acetylcholinesterase (AChE) activity was investigated in order to evaluate the mode of action and toxicity of chlorpyrifos in the presence of these herbicides. Results indicate that both binary mixtures elicited synergistic responses on the swimming behaviour of zebrafish larvae. Moreover, although the herbicides were not effective inhibitors of the AChE on their own, a synergistic inhibition of the enzyme activity was obtained by exposure to mixtures with chlorpyrifos. We observed a correlation between impairment of swimming behaviour of the larvae and inhibition of AChE activity. This study supports previous studies concerning the risk assessment of mixtures since the toxicity may be underestimated when looking only at the single toxicants and not their mixtures.

  5. Evaluation of temephos and chlorpyrifos-methyl against Culex pipiens (Diptera: Culicidae) larvae in septic tanks in Antalya, Turkey.

    PubMed

    Cetin, H; Yanikoglu, A; Kocak, O; Cilek, J E

    2006-11-01

    The larvicidal activity of chlorpyrifos-methyl and temephos was evaluated against Culex pipiens L. (Diptera: Culicidae) in septic tanks in Antalya, Turkey. Chlorpyrifos-methyl (Pyrifos MT 25 emulsifiable concentrate [EC] ) was evaluated at application rates of 0.04, 0.08, and 0.12 mg active ingredient (AI)/liter, and temephos (Temeguard 50 EC) was evaluated at 0.02, 0.04, and 0.06 mg (AI)/liter during a 21-d study. Generally, overall larval reduction in septic tanks from single- and multifamily dwellings treated with either larvicide was significantly greater than pretreatment levels and control tanks for the duration of the study. At 14 d posttreatment, duration of control was greatest in multifamily tanks treated with chlorpyrifos-methyl at the highest application rate with similar levels of control through 21 d for single-family dwellings (range 97-100%). Septic tanks from both types of family dwellings treated at the highest application rate of temephos resulted in >90% reduction through day 21 (range 91-100%). Laboratory bioassays of septic tank water treated at field application rates, without daily dilution, revealed that complete larval mortality was achieved for 21 d at each application rate and formulation. It is thought that daily addition of water and organic matter to the septic tanks in the single and multifamily dwellings influenced the duration of effectiveness of the larvicides.

  6. Determination of selected pesticides in water samples adjacent to agricultural fields and removal of organophosphorus insecticide chlorpyrifos using soil bacterial isolates

    NASA Astrophysics Data System (ADS)

    Hossain, M. S.; Chowdhury, M. Alamgir Zaman; Pramanik, Md. Kamruzzaman; Rahman, M. A.; Fakhruddin, A. N. M.; Alam, M. Khorshed

    2015-06-01

    The use of pesticide for crops leads to serious environmental pollution, therefore, it is essential to monitor and develop approaches to remove pesticide from contaminated environment. In this study, water samples were collected to monitor pesticide residues, and degradation of chlorpyrifos was also performed using soil bacteria. Identification of pesticide residues and determination of their levels were performed by high-performance liquid chromatography with photodiode array detector. Among 12 samples, 10 samples were found contaminated with pesticides. Chlorpyrifos was detected in four tested samples and concentrations ranged from 3.27 to 9.31 μg/l whereas fenitrothion ranging from (Below Detection Limit, <0.1 μg/l) to 33.41 μg/l in the tested samples. Parathion was found in two tested samples at the concentration of 0.73 and 6.23 μg/l. None of the tested samples was found contaminated with Methoxychlor, DDT and Ethion. Three soil bacterial isolates, Pseudomonas peli BG1, Burkholderia caryophylli BG4 and Brevundimonas diminuta PD6 degraded chlorpyrifos completely in 8, 10 and 10 days, respectively, when 20 mg/l chlorpyrifos was supplied as sole source of carbon. Whereas, BG1, BG4 and PD6 took 14, 16 and 16 days, respectively, for complete removal of 50 mg/l chlorpyrifos. Chlorpyrifos degradation rates were found maximum by all three isolates at 2nd day of incubation for both tested concentrations. The results of the present study suggest the need for regular monitoring of pesticide residues in water, to protect the aquatic environment. Chlorpyrifos degrading bacterial isolates can be used to clean up environmental samples contaminated with the organophosphate pesticides.

  7. The integrated phenotype.

    PubMed

    Murren, Courtney J

    2012-07-01

    Proper functioning of complex phenotypes requires that multiple traits work together. Examination of relationships among traits within and between complex characters and how they interact to function as a whole organism is critical to advancing our understanding of evolutionary developmental plasticity. Phenotypic integration refers to the relationships among multiple characters of a complex phenotype, and their relationships with other functional units (modules) in an organism. In this review, I summarize a brief history of the concept of phenotypic integration in plant and animal biology. Following an introduction of concepts, including modularity, I use an empirical case-study approach to highlight recent advance in clarifying the developmental and genomic basis of integration. I end by highlighting some novel approaches to genomic and epigenetic perturbations that offer promise in further addressing the role of phenotypic integration in evolutionary diversification. In the age of the phenotype, studies that examine the genomic and developmental changes in relationships of traits across environments will shape the next chapter in our quest for understanding the evolution of complex characters.

  8. Polypyrrole/montmorillonite nanocomposite as a new solid phase microextraction fiber combined with gas chromatography-corona discharge ion mobility spectrometry for the simultaneous determination of diazinon and fenthion organophosphorus pesticides.

    PubMed

    Jafari, Mohammad T; Saraji, Mohammad; Sherafatmand, Hossein

    2014-03-01

    A novel solid phase microextraction (SPME) fiber was prepared and coupled with gas chromatography corona discharge ion mobility spectrometry (GC-CD-IMS) based on polypyrrole/montmorillonite nanocomposites for the simultaneous determination of diazinon and fenthion. The nanocomposite polymer was coated using a three-electrode electrochemical system and directly deposited on a Ni-Cr wire by applying a constant potential. The scanning electron microscopy images revealed that the new fiber exhibited a rather porous and homogenous surface. The thermal stability of the fabricated fiber was investigated by thermogravimetric analysis. The effects of different parameters influencing the extraction efficiency such as extraction temperature and time, salt addition, stirring rate, the amount of nanoclay, and desorption temperature were investigated and optimized. The method was exhaustively evaluated in terms of sensitivity, recovery, and reproducibility. The linearity ranges of 0.05-10 and 0.08-10 μg L(-1), and the detection limits of 0.020 and 0.035 μg L(-1) were obtained for diazinon and fenthion, respectively. The relative standard deviation values were calculated to be lower than 5% and 8% for intra-day and inter-day, respectively. Finally, the developed method was applied to determine the diazinon and fenthion (as model compounds) in cucumber, lettuce, apple, tap and river water samples. The satisfactory recoveries revealed the capability of the two-dimensional separation technique (retention time in GC and drift time in IMS) for the analysis of complex matrices extracted by SPME. PMID:24528846

  9. Characterization and expression analysis of peroxiredoxin family genes from the silkworm Bombyx mori in response to phoxim and chlorpyrifos.

    PubMed

    Shi, Gui-Qin; Zhang, Ze; Jia, Kun-Lun; Zhang, Kun; An, Dong-Xu; Wang, Gang; Zhang, Bao-Long; Yin, He-Nan

    2014-09-01

    The organophosphorus pesticide poisoning of the silkworm Bombyx mori is one of the major events causing serious damage to sericulture. Some antioxidant enzymes play roles in regulating generation of reactive oxygen species (ROS) by pesticides including phoxim and chlorpyrifos, but relatively little is known about their effects on the silkworm peroxiredoxin family genes. Here, five peroxiredoxin (Prx) genes have been identified in silkworm genome, and Prx genes of silkworm and mammalian homologs have apparent ortholog relationship. Based on the genomic DNA sequence, putative 5'-flanking region of five BmPrxs were obtained and the transcription factor binding sites were predicted. Their expression profiles exposed to different concentrations of phoxim and chlorpyrifos for 24 h, 48 h and 72 h in midgut of silkworm were investigated using quantitative RT-PCR (qRT-PCR). The results showed that five BmPrxs and dual oxidase (BmDUOX) gene were all expressed in midgut of silkworm. After feeding with 0.375 mg/L and 0.75 mg/L phoxim, the transcription levels of BmPrx3 and BmPrx5 that can be located in mitochondria reached their peak levels at an early time point (24h). However, the transcription levels of BmPrx4 and BmPrx6 that can be addressed to secrete from the cell and cytosol, respectively, reached their peak levels at a later time point (72 h). Similar to expose to phoxim, the transcription levels of BmPrx3 and BmPrx5 that can be located in mitochondria reached their peak levels at an early time point (24 h) under chlorpyrifos stress. However, the transcription levels of BmPrx4 and BmPrx6 that can be addressed to secrete from the cell and cytosol, respectively, reached their peak levels at a later time point (72 h) under chlorpyrifos stress. These results revealed that BmPrxs that can be located in mitochondria were able to protect cells even more efficiently than cytosolic from an oxidative stress caused by OP. In addition, BmDUOX was also induced by phomix and

  10. Comparative chlorpyrifos pharmacokinetics via multiple routes of exposure and vehicles of administration in the adult rat.

    PubMed

    Smith, Jordan Ned; Campbell, James A; Busby-Hjerpe, Andrea L; Lee, Sookwang; Poet, Torka S; Barr, Dana B; Timchalk, Charles

    2009-06-30

    Chlorpyrifos (CPF) is a commonly used organophosphorus pesticide. A number of toxicity and mechanistic studies have been conducted in animals, where CPF has been administered via a variety of different exposure routes and dosing vehicles. This study compared chlorpyrifos (CPF) pharmacokinetics using oral, intravenous (IV), and subcutaneous (SC) exposure routes and corn oil, saline/Tween 20, and dimethyl sulfoxide (DMSO) as dosing vehicles. Two groups of rats were co-administered target doses (5 mg/kg) of CPF and isotopically labeled CPF (L-CPF). One group was exposed by both oral (CPF) and IV (L-CPF) routes using saline/Tween 20 vehicle; whereas, the second group was exposed by the SC route using two vehicles, corn oil (CPF) and DMSO (L-CPF). A third group was only administered CPF by the oral route in corn oil. For all treatments, blood and urine time course samples were collected and analyzed for 3,5,6-trichloro-2-pyridinol (TCPy), and isotopically labeled 3,5,6-trichloro-2-pyridinol (L-TCPy). Peak TCPy/L-TCPy concentrations in blood (20.2 micromol/l), TCPy/L-TCPy blood AUC (94.9 micromol/lh), and percent of dose excreted in urine (100%) were all highest in rats dosed orally with CPF in saline/Tween 20 and second highest in rats dosed orally with CPF in corn oil. Peak TCPy concentrations in blood were more rapidly obtained after oral administration of CPF in saline/Tween 20 compared to all other dosing scenarios (>1.5 h). These results indicate that orally administered CPF is more extensively metabolized than systemic exposures of CPF (SC and IV), and vehicle of administration also has an effect on absorption rates. Thus, equivalent doses via different routes and/or vehicles of administration could potentially lead to different body burdens of CPF, different rates of bioactivation to CPF-oxon, and different toxic responses. Simulations using a physiologically based pharmacokinetic and pharmacodynamic (PBPK/PD) model for CPF are consistent with these possibilities

  11. Oral intake of hydrogen-rich water ameliorated chlorpyrifos-induced neurotoxicity in rats

    SciTech Connect

    Wang, Tingting; Zhao, Ling; Liu, Mengyu; Xie, Fei; Ma, Xuemei Zhao, Pengxiang; Liu, Yunqi; Li, Jiala; Wang, Minglian; Yang, Zhaona; Zhang, Yutong

    2014-10-01

    Chronic exposure to low-levels of organophosphate (OP) compounds, such as chlorpyrifos (CPF), induces oxidative stress and could be related to neurological disorders. Hydrogen has been identified as a novel antioxidant which could selectively scavenge hydroxyl radicals. We explore whether intake of hydrogen-rich water (HRW) can protect Wistar rats from CPF-induced neurotoxicity. Rats were gavaged daily with 6.75 mg/kg body weight (1/20 LD{sub 50}) of CPF and given HRW by oral intake. Nissl staining and electron microscopy results indicated that HRW intake had protective effects on the CPF-induced damage of hippocampal neurons and neuronal mitochondria. Immunostaining results showed that the increased glial fibrillary acidic protein (GFAP) expression in astrocytes induced by CPF exposure can be ameliorated by HRW intake. Moreover, HRW intake also attenuated CPF-induced oxidative stress as evidenced by enhanced level of MDA, accompanied by an increase in GSH level and SOD and CAT activity. Acetylcholinesterase (AChE) activity tests showed significant decrease in brain AChE activity after CPF exposure, and this effect can be ameliorated by HRW intake. An in vitro study demonstrated that AChE activity was more intense in HRW than in normal water with or without chlorpyrifos-oxon (CPO), the metabolically-activated form of CPF. These observations suggest that HRW intake can protect rats from CPF-induced neurotoxicity, and the protective effects of hydrogen may be mediated by regulating the oxidant and antioxidant status of rats. Furthermore, this work defines a novel mechanism of biological activity of hydrogen by directly increasing the AChE activity. - Highlights: • Hydrogen molecules protect rats from CPF-induced damage of hippocampal neurons. • The increased GFAP expression induced by CPF can also be ameliorated by hydrogen. • Hydrogen molecules attenuated the increase in CPF-induced oxidative stress. • Hydrogen molecules attenuated AChE inhibition in vivo

  12. Effect of in vivo nicotine exposure on chlorpyrifos pharmacokinetics and pharmacodynamics in rats

    SciTech Connect

    Lee, Soo Kwang; Poet, Torka S.; Smith, Jordan N.; Busby-Hjerpe, Andrea L.; Timchalk, Charles

    2010-03-30

    Chlorpyrifos (CPF) is one of the most studied and widely used broad spectrum organophosphorus (OP) insecticides. The neurotoxicity of CPF results from inhibition of cholinesterase (ChE) by its metabolite, chlorpyrifos-oxon (CPF-oxon), which subsequently leads to cholinergic hyperstimulation. The routine consumption of alcoholic beverages and tobacco products will modify a number of metabolic and physiological processes which may impact the metabolism and pharmacokinetics of other xenobiotics including pesticides. The objective of this study was to evaluate the influence of repeated ethanol and nicotine co-exposure on in vivo CPF pharmacokinetics and pharmacodynamics. The major CPF metabolite, 3,5,6-trichloro-2-pyridinol (TCPy) in blood and urine along with changes in plasma and brain AChE activities were measured in male Sprague-Dawley (S-D) rats. Animals were repeatedly treated with either saline or ethanol (1 g/kg/day, po) and nicotine (1 mg/kg/day, sc) in addition to CPF (1 or 5 mg/kg/day, po) for 7 days. Rats were sacrificed at times from 1 to 24 hr post-last dosing of CPF. There were apparent differences in blood TCPy pharmacokinetics following ethanol and nicotine pretreatments in both CPF dose groups, which showed higher TCPy peak concentrations and increased blood TCPy AUC in ethanol and nicotine groups over CPF-only (~1.8- and 3.8-fold at 1 and 5 mg CPF doses, respectively). Brain acetylcholinesterase (AChE) activities from both ethanol and nicotine-treated groups showed substantially less inhibition following repeated 5 mg CPF/kg dosing compared to CPF-only controls (96 ± 13 and 66 ± 7% of naïve at 4 hr post-last CPF dosing, respectively). Inhibition of brain AChE activities was minimal in both 1 mg CPF/kg/day dosing groups, but a similar trend indicating less inhibition following ethanol/nicotine pretreatment was apparent. No differences were observed in plasma ChE activities due to the combined alcohol and nicotine treatments. In vitro, CPF

  13. Autophagy regulates chlorpyrifos-induced apoptosis in SH-SY5Y cells

    SciTech Connect

    Park, Jae Hyeon; Lee, Jeong Eun; Shin, In Chul; Koh, Hyun Chul

    2013-04-01

    Recent studies have shown that up-regulation of autophagy may be a tractable therapeutic intervention for clearing disease-causing proteins, including α-synuclein, ubiquitin, and other misfolded or aggregated proteins in pesticide-induced neurodegeneration. In a previous study, we reported that chlorpyrifos (CPF)-induced mitochondria-dependent apoptosis is mediated through reactive oxygen species in SH-SY5Y cells. In this study, we explored a novel pharmacotherapeutic approach to prevent CPF neurotoxicity involving the regulation of autophagy. We investigated the modulation of CPF-induced apoptosis according to autophagy regulation. We found that CPF induced apoptosis in SH-SY5Y cells, as demonstrated by the activation of caspase-3 and nuclear condensation. In addition, we observed that cells treated with CPF underwent autophagic cell death by monitoring the expression of LC3-II and p62. Pretreatment with the autophagy inducer rapamycin significantly enhanced the cell viability of CPF-exposed cells, and the enhancement of cell viability was partially due to alleviation of CPF-induced apoptosis via a decrease in levels of cleaved caspase-3. Specifically, rapamycin pretreatment decreased Bax and increased Bcl-2 expression in mitochondria. In addition, rapamycin significantly decreased cytochrome c release in from mitochondria into the cytosol. However, pretreatment of cells with the autophagy inhibitor, 3-methyladenine (3MA), remarkably increased CPF toxicity in these cells; this with correlated with increased expression of Bax and decreased expression of Bcl-2 in mitochondria. Our results suggest that CPF-induced cytotoxicity is modified by autophagy regulation and that rapamycin protects against CPF-induced apoptosis by enhancing autophagy. Pharmacologic induction of autophagy by rapamycin may be a useful treatment strategy in neurodegenerative disorders. - Highlights: ► Chlorpyrifos (CPF) is cytotoxic to SH-SY5Y cells ► CPF-induced cytotoxicity is mediated by

  14. Phenotypic malignant changes and untargeted lipidomic analysis of long-term exposed prostate cancer cells to endocrine disruptors

    SciTech Connect

    Bedia, Carmen Dalmau, Núria Jaumot, Joaquim Tauler, Romà

    2015-07-15

    Endocrine disruptors (EDs) are a class of environmental toxic molecules able to interfere with the normal hormone metabolism. Numerous studies involve EDs exposure to initiation and development of cancers, including prostate cancer. In this work, three different EDs (aldrin, aroclor 1254 and chlorpyrifos (CPF)) were investigated as potential inducers of a malignant phenotype in DU145 prostate cancer cells after a chronic exposure. Epithelial to mesenchymal transition (EMT) induction, proliferation, migration, colony formation and release of metalloproteinase 2 (MMP-2) were analyzed in 50-day exposed cells to the selected EDs. As a result, aldrin and CPF exposure led to an EMT induction (loss of 16% and 14% of E-cadherin levels, respectively, compared to the unexposed cells). Aroclor and CPF presented an increased migration (134% and 126%, respectively), colony formation (204% and 144%, respectively) and MMP-2 release (137% in both cases) compared to the unexposed cells. An untargeted lipidomic analysis was performed to decipher the lipids involved in the observed transformations. As general results, aldrin exposure showed a global decrease in phospholipids and sphingolipids, and aroclor and CPF showed an increase of certain phospholipids, glycosphingolipids as well as a remarkable increase of some cardiolipin species. Furthermore, the three exposures resulted in an increase of some triglyceride species. In conclusion, some significant changes in lipids were identified and thus we postulate that some lipid compounds and lipid metabolic pathways could be involved in the acquisition of the malignant phenotype in exposed prostate cancer cells to the selected EDs. - Highlights: • Aldrin, aroclor and chlorpyrifos induced an aggressive phenotype in DU145 cells. • An untargeted lipidomic analysis has been performed on chronic exposed cells. • Lipidomic results showed changes in specific lipid species under chronic exposure. • These lipids may have a role in the

  15. Use of organic amendments as a bioremediation strategy to reduce the bioavailability of chlorpyrifos insecticide in soils. Effects on soil biology.

    PubMed

    Tejada, Manuel; Gómez, Isidoro; Del Toro, Marina

    2011-10-01

    The sorption capacity of both an organic municipal solid waste by-product (MSW) and a cow manure (CM) in a soil polluted with chlorpyrifos, as well as its effect on soil microbial activity, and weight, reproductive parameters and glutathione-S-transferase activity of two earthworm species (Eisenia fetida and Lumbricus terrestris) were studied. Chlorpyrifos was added at the recommended application rate (5 L ha(-1); 768 mg chlorpyrifos kg(-1)) and treated with MSW at a rate of 10% and CM at a rate of 5.8% in order to apply the same amount of organic matter to the soil. An unamended polluted soil was used as control. Earthworm cocoon number, average weight of cocoon, and number of juveniles per cocoon were measured after 30 days of incubation, whereas soil enzymatic activities, earthworm weight, and glutathione-S-transferase activity of earthworms were measured after 3, 45 and 90 days. Soil enzymatic activities, reproductive and glutathione-S-transferase activity in both worms decreased in polluted soil. The inhibition percentage of soil enzymatic activities, reproductive and glutathione-S-transferase activity in both worms was lower in MSW-amended soil than for CM-amended soil. The toxic effect of chlorpyrifos on E. fetida was lowest compared to L. terrestris. This suggested that the addition of organic wastes with higher humic than fulvic acid concentration is more beneficial for remediation of soils polluted with chlorpyrifos.

  16. Use of organic amendments as a bioremediation strategy to reduce the bioavailability of chlorpyrifos insecticide in soils. Effects on soil biology.

    PubMed

    Tejada, Manuel; Gómez, Isidoro; Del Toro, Marina

    2011-10-01

    The sorption capacity of both an organic municipal solid waste by-product (MSW) and a cow manure (CM) in a soil polluted with chlorpyrifos, as well as its effect on soil microbial activity, and weight, reproductive parameters and glutathione-S-transferase activity of two earthworm species (Eisenia fetida and Lumbricus terrestris) were studied. Chlorpyrifos was added at the recommended application rate (5 L ha(-1); 768 mg chlorpyrifos kg(-1)) and treated with MSW at a rate of 10% and CM at a rate of 5.8% in order to apply the same amount of organic matter to the soil. An unamended polluted soil was used as control. Earthworm cocoon number, average weight of cocoon, and number of juveniles per cocoon were measured after 30 days of incubation, whereas soil enzymatic activities, earthworm weight, and glutathione-S-transferase activity of earthworms were measured after 3, 45 and 90 days. Soil enzymatic activities, reproductive and glutathione-S-transferase activity in both worms decreased in polluted soil. The inhibition percentage of soil enzymatic activities, reproductive and glutathione-S-transferase activity in both worms was lower in MSW-amended soil than for CM-amended soil. The toxic effect of chlorpyrifos on E. fetida was lowest compared to L. terrestris. This suggested that the addition of organic wastes with higher humic than fulvic acid concentration is more beneficial for remediation of soils polluted with chlorpyrifos. PMID:21813178

  17. An engineered microorganism can simultaneously detoxify cadmium, chlorpyrifos, and γ-hexachlorocyclohexane.

    PubMed

    Yang, Chao; Yu, Huilei; Jiang, Hong; Qiao, Chuanling; Liu, Ruihua

    2016-07-01

    Many ecosystems are currently co-contaminated with heavy metals such as cadmium (Cd(2+) ) and pesticides such as chlorpyrifos (CP) and γ-hexachlorocyclohexane (γ-HCH). A feasible approach to remediate the combined pollution of heavy metals and pesticides is the use of γ-HCH degrading bacteria endowed with CP hydrolysis and heavy metal biosorption capabilities. In this work, a recombinant microorganism capable of simultaneously detoxifying Cd(2+) , CP, and γ-HCH was constructed by display of synthetic phytochelatins (EC20) and methyl parathion hydrolase (MPH) fusion protein on the cell surface of the γ-HCH degrading Sphingobium japonicum UT26 using the truncated ice nucleation protein (INPNC) as an anchoring motif. The surface localization of INPNC-EC20-MPH was verified by cell fractionation, Western blot analysis, immunofluorescence microscopy, and proteinase accessibility experiment. Expression of EC20 on the cell surface not only improved Cd(2+) binding but also alleviated the cellular toxicity of Cd(2+) . As expected, the rates of CP and γ-HCH degradation were reduced in the presence of Cd(2+) for cells without EC20 expression. However, expression of EC20 (higher Cd(2+) accumulation) significantly restored the levels of CP and γ-HCH degradation. These results demonstrated that surface display of EC20 enhanced not only Cd(2+) accumulation but also protected the recombinant strain against the toxic effects of Cd(2+) on CP and γ-HCH degradation. PMID:26648050

  18. Biochemical changes in certain enzymes of Lysapsus limellium (Anura: Hylidae) exposed to chlorpyrifos.

    PubMed

    Maximiliano Attademo, Andrés; Mariela Peltzer, Paola; Carlos Lajmanovich, Rafael; Cabagna-Zenklusen, Mariana; María Junges, Celina; Lorenzatti, Eduardo; Aró, Carolina; Grenón, Paula

    2015-03-01

    Different enzyme biomarkers (AChE: acetylcholinesterase, CbE: carboxylesterase, GST: glutathione-S-transferase, CAT: catalase) were measured in digestive tissues of Lysapsus limellum frogs collected from a rice field (RF: chlorpyriphos sprayed by aircraft) and a non-contaminated area (RS: reference site), immediately (24h) and 168 h after aerial spraying with chlorpyrifos (CPF). CPF degradation was also searched in water samples collected from RF and RS, and found that insecticide concentration was reduced to≈6.78% of the original concentration in RF at 168 h. A significant reduction of AChE and CbE activities was detected in L. limellum from RF in stomach and liver at 24 and 168 h, and in intestine only at 24h, with respect to RS individuals. CAT activity decreased in intestine of L. limellum from RF 24h and 168 h after exposure to CPF, whereas GST decreased in that tissue only at 24h. In stomach and liver, a decrease was observed only at 168 h in both CAT and GST. The use of biomarkers (AChE, CbE, GST, and CAT) provides different lines of evidences for ecotoxicological risk assessment of wild frog populations at sites contaminated with pesticides.

  19. Repeated exposures to chlorpyrifos lead to spatial memory retrieval impairment and motor activity alteration.

    PubMed

    Yan, Changhui; Jiao, Lifei; Zhao, Jun; Yang, Haiying; Peng, Shuangqing

    2012-07-01

    Chlorpyrifos (CPF) is one of the most commonly used insecticides throughout the world and has become one of the major pesticides detected in farm products. Chronic exposures to CPF, especially at the dosages without eliciting any systemic toxicity, require greater attention. The purpose of this study was, therefore, to evaluate the behavioral effects of repeated low doses (doses that do not produce overt signs of cholinergic toxicity) of CPF in adult rats. Male rats were given 0, 1.0, 5.0 or 10.0mg/kg of CPF through intragastric administration daily for 4 consecutive weeks. The behavioral functions were assessed in a series of behavioral tests, including water maze task, open-field test, grip strength and rotarod test. Furthermore, the present study was designed to evaluate the effects of repeated exposures to CPF on water maze recall and not acquisition. The results showed that the selected doses only had mild inhibition effects on cholinesterase activity, and have no effects on weight gain and daily food consumption. Performances in the spatial retention task (Morris water maze) were impaired after the 4-week exposure to CPF, but the performances of grip strength and rotarod test were not affected. Motor activities in the open field were changed, especially the time spent in the central zone increased. The results indicated that repeated exposures to low doses of CPF may lead to spatial recall impairments, behavioral abnormalities. However, the underlying mechanism needs further investigations.

  20. Toxicity interaction between chlorpyrifos, mancozeb and soil moisture to the terrestrial isopod Porcellionides pruinosus.

    PubMed

    Morgado, Rui G; Gomes, Pedro A D; Ferreira, Nuno G C; Cardoso, Diogo N; Santos, Miguel J G; Soares, Amadeu M V M; Loureiro, Susana

    2016-02-01

    A main source of uncertainty currently associated with environmental risk assessment of chemicals is the poor understanding of the influence of environmental factors on the toxicity of xenobiotics. Aiming to reduce this uncertainty, here we evaluate the joint-effects of two pesticides (chlorpyrifos and mancozeb) on the terrestrial isopod Porcellionides pruinosus under different soil moisture regimes. A full factorial design, including three treatments of each pesticide and an untreated control, were performed under different soil moisture regimes: 25%, 50%, and 75% WHC. Our results showed that soil moisture had no effects on isopods survival, at the levels assessed in this experiment, neither regarding single pesticides nor mixture treatments. Additivity was always the most parsimonious result when both pesticides were present. Oppositely, both feeding activity and biomass change showed a higher sensitivity to soil moisture, with isopods generally showing worse performance when exposed to pesticides and dry or moist conditions. Most of the significant differences between soil moisture regimes were found in single pesticide treatments, yet different responses to mixtures could still be distinguished depending on the soil moisture assessed. This study shows that while soil moisture has the potential to influence the effects of the pesticide mixture itself, such effects might become less important in a context of complex combinations of stressors, as the major contribution comes from its individual interaction with each pesticide. Finally, the implications of our results are discussed in light of the current state of environmental risk assessment procedures and some future perspectives are advanced. PMID:26539709

  1. In vitro protection of human lymphocytes from toxic effects of chlorpyrifos by selenium-enriched medicines

    PubMed Central

    Navaei-Nigjeh, Mona; Asadi, Hamidreza; Baeeri, Maryam; Pedram, Sahar; Rezvanfar, Mohammad Amin; Mohammadirad, Azadeh; Abdollahi, Mohammad

    2015-01-01

    Objective(s): Chlorpyrifos (CP) is a broad-spectrum organophosphorus pesticide used extensively in agricultural and domestic pest control, accounting for 50% of the global insecticidal use. In the present study, protective effects of two selenium-enriched strong antioxidative medicines IMOD and Angipars were examined in human lymphocytes treated with CP in vitro. Materials and Methods: Isolated lymphocytes were exposed to 12 µg/ml CP either alone or in combination with effective doses (ED50) of IMOD (0.2 µg/ml) and Angipars (1 µg/ml). After 3 days incubation, the viability and oxidative stress markers including cellular lipid peroxidation (LPO), myeloperoxidase (MPO), total thiol molecules (TTM), and total antioxidant power (TAP) were evaluated. Also, the levels of tumor necrosis factor-α (TNF-α), as inflammatory index along with acetylcholinesterase (AChE) activity and cell apoptosis were assessed by flow cytometry. Results: Results indicated that effective doses of IMOD and Angipars reduced CP-exposed lymphocyte mortality rate along with oxidative stress. Both agents restored CP-induced elevation of TNF-α and protected the lymphocytes from CP-induced apoptosis and necrosis. Conclusion: Overall, results confirm that IMOD and Angipars reduce the toxic effects associated with CP through free radical scavenging and protection from apoptosis and necrosis. PMID:25945242

  2. Neurobehavioral evaluation of adolescent male rats following repeated exposure to chlorpyrifos.

    PubMed

    Chen, Wen-Qiang; Zhang, You-Zhi; Yuan, Li; Li, Yun-Feng; Li, Jin

    2014-06-01

    Chlorpyrifos (CPF), a highly effective organophosphate pesticide (OP), is extensively used worldwide. However, its agricultural use was extensively reduced in 2001. Several studies have suggested an association between mood disorders and CPF exposure in humans, especially in children, a subgroup that is highly susceptible to xenobiotics. We investigated the hypothesis that repeated CPF exposure in animals would elicit depressive-like behavioral alterations that reflected depression-related symptoms. Adolescent male rats were subcutaneously injected with either olive oil or 2.5, 5, 10, or 20mg/kg CPF from postnatal day 27 to 36, then were followed by a series of neurobehavioral evaluation. Our studies revealed depressive-like alterations that were manifested by increased despair behavior in the forced swimming test, increased escape failure in the learned helplessness test, and altered approach-avoidance conflict in the novelty-suppressed feeding test. There was no effect on locomotor activity in the open-field activity test. This study indicates that repeated exposure to CPF elicits depressive-like behavioral alterations in adolescent male rats. PMID:24708925

  3. Bacterial assisted degradation of chlorpyrifos: The key role of environmental conditions, trace metals and organic solvents.

    PubMed

    Khalid, Saira; Hashmi, Imran; Khan, Sher Jamal

    2016-03-01

    Wastewater from pesticide industries, agricultural or surface runoff containing pesticides and their residues has adverse environmental impacts. Present study demonstrates effect of petrochemicals and trace metals on chlorpyrifos (CP) biotransformation often released in wastewater of agrochemical industry. Biodegradation was investigated using bacterial strain Pseudomonas kilonensis SRK1 isolated from wastewater spiked with CP. Optimal environmental conditions for CP removal were CFU (306 × 10(6)), pH (8); initial CP concentration (150 mg/L) and glucose as additional carbon source. Among various organic solvents (petrochemicals) used in this study toluene has stimulatory effect on CP degradation process using SRK1, contrary to this benzene and phenol negatively inhibited degradation process. Application of metal ions (Cu (II), Fe (II) Zn (II) at low concentration (1 mg/L) took part in biochemical reaction and positively stimulated CP degradation process. Metal ions at high concentrations have inhibitory effect on degradation process. A first order growth model was shown to fit the data. It could be concluded that both type and concentration of metal ions and petrochemicals can affect CP degradation process.

  4. Neurobehavioral and biochemical changes in Nauphoeta cinerea following dietary exposure to chlorpyrifos.

    PubMed

    Adedara, Isaac A; Rosemberg, Denis B; de Souza, Diego; Farombi, Ebenezer O; Aschner, Michael; Souza, Diogo O; Rocha, Joao B T

    2016-06-01

    The present study aimed to increase our understanding about the mode of toxic action of organophosphate pesticides in insects by evaluating the biochemical and neurobehavioral characteristics in Nauphoeta cinerea exposed to chlorpyrifos (CPF)-contaminated diet. The insects were exposed for 35 consecutive days to CPF at 0.078, 0.15625, 0.3125 and 0.625μg/g feed. Locomotor behavior was assessed for a 10-min trial in a novel arena and subsequently, biochemical analyses were carried out using the cockroaches' heads. In comparison to control, CPF-exposed cockroaches showed significant decreases in the total distance traveled, body rotation, turn angle and meandering, along with significant increase in the number of falls, time and episodes of immobility. The marked decrease in the exploratory profiles of CPF-exposed cockroaches was confirmed by track plots, whereas occupancy plot analyses showed a progressive dispersion at 0.15625μg/g feed group. Moreover, the heads of CPF-exposed cockroaches showed marked decrease in acetylcholinesterase activity and antioxidant status with concomitant significant elevation in dichlorofluorescein oxidation and lipid peroxidation levels in CPF-treated cockroaches. Gas Chromatography-Mass Spectrometry analyses revealed bioaccumulation of CPF in cockroaches exposed to concentrations above 0.078μg/g feed. The findings from this investigation showed N. cinerea as a value model organism for the risk assessment of environmental organophosphate contamination in insects.

  5. Tissue-specific inhibition and recovery of esterase activities in Lumbricus terrestris experimentally exposed to chlorpyrifos.

    PubMed

    Vejares, Sandra González; Sabat, Pablo; Sanchez-Hernandez, Juan C

    2010-04-01

    Exposure and effect assessment of organophosphate (OP) pesticides generally involves the use of cholinesterase (ChE) inhibition. In earthworm, this enzyme activity is often measured in homogenates from the whole organism. Here we examine the tissue-specific response of ChE and carboxylesterase (CE) activities in Lumbricus terrestris experimentally exposed to chlorpyrifos-spiked field soils. Esterases were measured in different gut segments and in the seminal vesicles of earthworms following acute exposure (2 d) to the OP and during 35d of a recovery period. We found that inhibition of both esterase activities was dependent on the tissue. Cholinesterase activity decreased in the pharynx, crop, foregut and seminal vesicles in a concentration-dependent way, whereas CE activity (4-nitrophenyl valerate) was strongly inhibited in these tissues. Gizzard CE activity was not inhibited by the OP, even an increase of enzyme activity was evident during the recovery period. These results suggest that both esterases should be determined jointly in selected tissues of earthworms. Moreover, the high levels of gut CE activity and its inhibition and recovery dynamic following OP exposure suggest that this esterase could play an important role as an enzymatic barrier against OP uptake from the ingested contaminated soil. PMID:20045489

  6. Effectiveness of dishwashing liquids in removing chlorothalonil and chlorpyrifos residues from cherry tomatoes.

    PubMed

    Wang, Zhiwei; Huang, Jiexun; Chen, Jinyuan; Li, Feili

    2013-08-01

    Washing is the most practical way to remove pesticide residues in fruits and vegetables. Two commonly used kitchen dishwashing liquids (detergents) in Chinese market were tested for enhanced removal of chlorpyrifos (CHP) and chlorothalonil (CHT) in cherry tomatoes by soaking the cherry tomatoes in the detergent solutions. The critical micelle concentrations of detergent A and detergent B were about 250 mg L(-1) and 444 mg L(-1), respectively. Detergent A had a higher solubilizing ability for pesticides and hence washing effectiveness than detergent B. The apparent solubility of CHP increased with increasing detergent concentration, while that of CHT remained comparatively invariant independent of detergent concentration within the tested range. The apparent solubility of CHP was also consistently higher in solutions of both detergents as compared to CHT. Due probably to its lower logKow value, CHT was more readily washed off cherry tomatoes than CHP. In terms of washing, a duration of 10-20 min was sufficient for removal of pesticides on cherry tomatoes in distilled water and detergent solutions. The effectiveness of removing pesticides increased with increasing detergent concentration from 50 mg L(-1) to 5 g L(-1), with up to 80% CHT and 42% CHP removed. Multiple washing further increased pesticide removal. Adding 10% acetic acid to lower pH or increasing washing temperature favored pesticide removal, but 10% NaCl produced the shielding effect and substantially reduced the effectiveness of detergent A for pesticide removal.

  7. Utilization of microbial community potential for removal of chlorpyrifos: a review.

    PubMed

    Yadav, Maya; Shukla, Awadhesh Kumar; Srivastva, Navnita; Upadhyay, Siddh Nath; Dubey, Suresh Kumar

    2016-08-01

    Chlorpyrifos (CP) is the most commonly used pesticide in agricultural fields worldwide. Exposure to CP and its metabolites creates severe neuron-disorders in human beings. Improper handling and uncontrolled application of CP by farmers have lead to the contamination of surface and ground water bodies. Biodegradation offers an efficient and cost effective method for the removal of CP and other toxic organophosphorus pesticides from the contaminated environment. The degradation of CP by various microorganisms has been investigated by several researchers over the past few years. This review presents a critical summary of the recent published results on the biodegradation of CP. A diverse range of bacterial species such as Agrobacterium sp., Alcaligenes faecalis, Enterobacter sp. Arthrobacter sp. Bacillus pumilus, Pseudomonas sp. etc., fungal species like Trichoderma viridae, Aspergillus niger, Verticillium sp., Acremonium sp. Cladosporium cladosporiodes, etc. and certain algal species viz. Chlorella vulgaris, Spirulina platensis, Synechocystis sp., etc., have been shown to degrade CP. The efficacy of these communities for CP degradation in batch and continuous modes has also been discussed but more studies are required on continuous reactors. Also, the available published information on kinetics of biodegradation of CP along with the available results on molecular biological approaches are discussed in this work. PMID:25782532

  8. How safe is the use of chlorpyrifos: Revelations through its effect on layer birds

    PubMed Central

    Singh, P. P.; Kumar, Ashok; Chauhan, R. S.; Pankaj, P. K.

    2016-01-01

    Aim: The present study was aimed to investigate the immunological competence of chlorpyrifos (CPF) insecticide after oral administration in layer chickens. Materials and Methods: A total of 20 White Leghorn birds were given CPF in drinking water at 0.3 ppm/bird/day (no observable effect level dose) for a period of 3-month. Immune competence status of layer birds and chicks hatched from CPF-treated birds were estimated at 15 days interval in layer birds and monthly interval in chicks using immunological and biochemical parameters. Results: There was a significant decrease in values of total leukocytes count, absolute lymphocyte count, absolute heterophil count, total serum protein, serum albumin, serum globulin, and serum gamma globulin in the birds treated with CPF as compared to control. Similarly, immune competence tests such as lymphocyte stimulation test, oxidative burst assay, and enzyme-linked immunosorbent assay tests indicated lower immunity in birds treated with CPF as compared to control. Subsequently, chicks produced from CPF-treated birds were also examined for immune competence, but no significant difference was observed between chicks of both the groups. Conclusion: The exposure to CPF produced hemo-biochemical and other changes that could be correlated with changes in the immunological profile of layer chickens suggesting total stoppage of using CPF in poultry sheds. PMID:27536038

  9. Adverse effects of exposure to low doses of chlorpyrifos in lactating rats.

    PubMed

    Mansour, Sameeh A; Mossa, Abdel-Tawab H

    2011-04-01

    This study was conducted to shed light on the effect of exposure of lactating rat to chlorpyrifos (CPF). CPF was orally administered to lactating rats at 0.01 mg kg(-1) b.wt. (acceptable daily intake, ADI), 1.00 mg kg(-1) b.wt. (no observed adverse effects level, NOAEL) and 1.35 mg kg(-1) b.wt. (1/100 LD( 50)) from postnatal day 1 (PN1) until day 20 (PN20) after delivery. Results indicated decreases in body weight and increases in relative liver and kidney weights of exposed dams. Significant damage to liver was observed via increased plasma levels of aminotransferases (aspartate aminotransferase (AST) and alanine aminotransferase (ALT)) lactate dehydrogenase (LDH) and γ-glutamyle transferase (γ-GT) in a dose-dependent manner. At two high doses of CPF (1.00 and 1.35 mg kg(-1) b.wt.), the lactating mothers showed significant decrease in the activity of cholinesterase (ChE). Lipid peroxidation was significantly increased, while glutathione s-transferase (GST) and superoxide dismutase (SOD) were significantly decreased compared to control. At high dose of CPF (1.35 mg kg(-1) b.wt.), total protein and uric acid levels were significantly increased. CPF caused dose-related histopathological changes in liver and kidney of the CPF-treated dams.

  10. Morbidity among employees engaged in the manufacture or formulation of chlorpyrifos.

    PubMed Central

    Brenner, F E; Bond, G G; McLaren, E A; Green, S; Cook, R R

    1989-01-01

    The prevalence of selected illnesses and symptoms during 1977-85 was compared between 175 employees potentially exposed to the organophosphate insecticide chlorpyrifos and 335 matched controls with no history of exposure to organophosphates. Subjects were subdivided into three exposure intensity groups on the basis of job title and air monitoring data for dose response testing. This classification scheme was shown roughly to correlate with plasma cholinesterase inhibition in the workers. No statistically significant differences in illness or prevalence of symptoms were observed between the exposed and unexposed groups or among the three exposure subgroups. Potentially exposed employees did report symptoms of dizziness and of malaise and fatigue relatively more often than subjects from the comparison group; however, further analyses by exposure level, process area, or time did not support a relation with exposure. No cases of peripheral neuropathy were seen among the exposed workers. Although the sample size was small and the statistical power limited, the cumulative exposures likely to have been experienced by this workforce exceed those to be expected for individuals using the product as recommended. The absence of exposure related adverse effects, including neurological impairment, is reassuring. PMID:2466478

  11. Morbidity among employees engaged in the manufacture or formulation of chlorpyrifos.

    PubMed

    Brenner, F E; Bond, G G; McLaren, E A; Green, S; Cook, R R

    1989-02-01

    The prevalence of selected illnesses and symptoms during 1977-85 was compared between 175 employees potentially exposed to the organophosphate insecticide chlorpyrifos and 335 matched controls with no history of exposure to organophosphates. Subjects were subdivided into three exposure intensity groups on the basis of job title and air monitoring data for dose response testing. This classification scheme was shown roughly to correlate with plasma cholinesterase inhibition in the workers. No statistically significant differences in illness or prevalence of symptoms were observed between the exposed and unexposed groups or among the three exposure subgroups. Potentially exposed employees did report symptoms of dizziness and of malaise and fatigue relatively more often than subjects from the comparison group; however, further analyses by exposure level, process area, or time did not support a relation with exposure. No cases of peripheral neuropathy were seen among the exposed workers. Although the sample size was small and the statistical power limited, the cumulative exposures likely to have been experienced by this workforce exceed those to be expected for individuals using the product as recommended. The absence of exposure related adverse effects, including neurological impairment, is reassuring.

  12. The effect of chlorpyrifos on thermogenic capacity of bank voles selected for increased aerobic exercise metabolism.

    PubMed

    Dheyongera, Geoffrey; Grzebyk, Katherine; Rudolf, Agata M; Sadowska, Edyta T; Koteja, Paweł

    2016-04-01

    Agro-chemicals potentially cause adverse effects in non-target organisms. The rate of animal energy metabolism can influence their susceptibility to pesticides by influencing food consumption, biotransformation and elimination rates of toxicants. We used experimental evolution to study the effects of inherent differences in energy metabolism rate and exposure to the organophosphate insecticide, chlorpyrifos (CPF) on thermogenic capacity in a wild rodent, the bank vole (Myodes = Clethrionomys glareolus). The voles were sampled from four replicate lines selected for high swim-induced aerobic metabolism (A) and four unselected control (C) lines. Thermogenic capacity, measured as the maximum cold-induced rate of oxygen consumption (VO2cold), was higher in the A - than C lines, and it decreased after continuous exposure to CPF via food or after a single dose administered via oral gavage, but only when measured shortly after exposure. VO2cold measured 24 h after repeated exposure was not affected. In addition, gavage with a single dose led to decreased food consumption and loss in body mass. Importantly, the adverse effects of CPF did not differ between the selected and control lines. Therefore, exposure to CPF has adverse effects on thermoregulatory performance and energy balance in this species. The effects are short-lived and their magnitude is not associated with the inherent level of energy metabolism. Even without severe symptoms of poisoning, fitness can be compromised under harsh environmental conditions, such as cold and wet weather.

  13. EEG spectra, behavioral states and motor activity in rats exposed to acetylcholinesterase inhibitor chlorpyrifos.

    PubMed

    Timofeeva, Olga A; Gordon, Christopher J

    2002-06-01

    Exposure to organophosphates (OP) has been associated with sleep disorders such as insomnia and "excessive dreaming." The central mechanisms of these effects are not well understood. OPs inhibit acetylcholinesterase (AChE) activity, leading to a hyperactivity of the brain cholinergic systems that are involved in sleep regulation. We studied alterations in the EEG, behavioral states, motor activity and core temperature in rats orally administered with 10 or 40 mg/kg of the OP insecticide chlorpyrifos (CHP). Occipital EEG, motor activity and core temperature were recorded with telemetric transmitters. Behavioral sleep-wake states were visually scored. Both doses of CHP produced alterations of the EEG (decrease in power of sigma/beta and increase in slow theta and fast gamma bands) characteristic of arousal. EEG alterations were consistent with behavioral changes such as an increase in wakefulness and a decrease in sleep. Waking immobility was a prevalent behavior. We did not detect any overt signs of CHP toxicity, such as an abnormal posture or gait, suggesting that reduced locomotion can be a result of central effects of CHP (such as activation of cholinergic motor inhibitory system) rather than peripheral (such as an impairment of neuromuscular function). Changes in the EEG and behavior occurred independently of the decrease in core temperature. Increased wakefulness together with reduced motor activity after exposure to CHP seems to be a result of hyperactivity in brain cholinergic neuronal networks. PMID:12175464

  14. Are circulating cytokines interleukin-6 and tumor necrosis factor alpha involved in chlorpyrifos-induced fever?

    PubMed

    Gordon, C J; Rowsey, P J

    1999-05-01

    Oral exposure to chlorpyrifos (CHP) in the rat results in an initial hypothermic response followed by a delayed fever. Fever from infection is mediated by the release of cytokines, including interleukin-6 (IL-6) and tumor necrosis factor (TNF alpha). This study determined if the CHP-induced fever involves cytokine-mediated mechanisms similar to that of infectious fevers. Long-Evans rats were gavaged with the corn oil vehicle or CHP (10-50 mg/kg). The rats were euthanized and blood collected at various times that corresponded with the hypothermic and febrile effects of CHP. Plasma IL-6, TNF alpha, cholinesterase activity (ChE), total iron, unsaturated iron binding capacity (UIBC), and zinc were measured. ChE activity was reduced by approximately 50% 4 h after CHP. There was no effect of CHP on IL-6 when measured during the period of CHP-induced hypothermia or fever. TNF alpha levels nearly doubled in female rats 48 h after 25 mg/kg CHP. The changes in plasma cytokine levels following CHP were relatively small when compared to > 1000-fold increase in IL-6 and > 10-fold rise in TNF alpha following lipopolysaccharide (E. coli; 50 microg/kg; i.p.)-induced fever. This does not preclude a role of cytokines in CHP-induced fever. Nonetheless, the data suggest that the delayed fever from CHP is unique, involving mechanisms other than TNF alpha and IL-6 release into the circulation characteristic of infectious fevers. PMID:10413184

  15. Effectiveness of dishwashing liquids in removing chlorothalonil and chlorpyrifos residues from cherry tomatoes.

    PubMed

    Wang, Zhiwei; Huang, Jiexun; Chen, Jinyuan; Li, Feili

    2013-08-01

    Washing is the most practical way to remove pesticide residues in fruits and vegetables. Two commonly used kitchen dishwashing liquids (detergents) in Chinese market were tested for enhanced removal of chlorpyrifos (CHP) and chlorothalonil (CHT) in cherry tomatoes by soaking the cherry tomatoes in the detergent solutions. The critical micelle concentrations of detergent A and detergent B were about 250 mg L(-1) and 444 mg L(-1), respectively. Detergent A had a higher solubilizing ability for pesticides and hence washing effectiveness than detergent B. The apparent solubility of CHP increased with increasing detergent concentration, while that of CHT remained comparatively invariant independent of detergent concentration within the tested range. The apparent solubility of CHP was also consistently higher in solutions of both detergents as compared to CHT. Due probably to its lower logKow value, CHT was more readily washed off cherry tomatoes than CHP. In terms of washing, a duration of 10-20 min was sufficient for removal of pesticides on cherry tomatoes in distilled water and detergent solutions. The effectiveness of removing pesticides increased with increasing detergent concentration from 50 mg L(-1) to 5 g L(-1), with up to 80% CHT and 42% CHP removed. Multiple washing further increased pesticide removal. Adding 10% acetic acid to lower pH or increasing washing temperature favored pesticide removal, but 10% NaCl produced the shielding effect and substantially reduced the effectiveness of detergent A for pesticide removal. PMID:23601120

  16. Toxicity of the insecticide chlorpyrifos to the South American toad Rhinella arenarum at larval developmental stage.

    PubMed

    Liendro, Natacha; Ferrari, Ana; Mardirosian, Mariana; Lascano, Cecilia I; Venturino, Andrés

    2015-03-01

    Chlorpyrifos (CPF) is an insecticide widely used for pest control in the fruit-productive region of North Patagonia, Argentina, where it is found in superficial waters. The aim of this study was to establish the toxic effects of CPF in Rhinella arenarum toad larvae as a potentially exposed species. We determined the 96 h-LC50 (1.46 ± 0.27 mg/L), the LOEC (0.81 mg/L, LC10) and NOEC (0.43 mg/L, LC1) for CPF lethality as endpoint. We also analyzed biochemical biomarkers in larvae exposed to sublethal CPF concentrations. The IC50 for cholinesterase was 0.113 ± 0.026 mg/L, one order of magnitude lower than the LC50. Carboxylesterase activity was inhibited, buffering OP toxicity on cholinesterase. Reduced glutathione increased after 24h as an antioxidant response, and decreased at 96 h together with catalase activity, due to oxidative stress. These biochemical effects suggest that environmentally relevant CPF concentrations pose a threat to R. arenarum larvae progression.

  17. Simultaneous Detection of Fenitrothion and Chlorpyrifos-Methyl with a Photonic Suspension Array

    PubMed Central

    Wang, Xuan; Mu, Zhongde; Shangguan, Fengqi; Liu, Ran; Pu, Yuepu; Yin, Lihong

    2013-01-01

    A technique was developed for simultaneous detection of fenitrothion (FNT) and chlorpyrifos-methyl (CLT) using a photonic suspension array based on silica colloidal crystal beads (SCCBs). The SCCBs were encoded with the characteristic reflection peak originating from the stop-band of colloidal crystal. This approach avoids the bleaching, fading or potential interference seen when encoding by fluorescence. SCCBs with a nanopatterned surface had increased biomolecule binding capacity and improved stability. Under optimal conditions, the proposed suspension array allowed simultaneous detection of the selected pesticides in the ranges of 0.25 to 1024 ng/mL and 0.40 to 735.37 ng/mL, with the limits of detection (LODs) of 0.25 and 0.40 ng/mL, respectively. The suspension array was specific and had no significant cross-reactivity with other chemicals. The mean recoveries in tests in which samples were spiked with target standards were 82.35% to 109.90% with a standard deviation within 9.93% for CLT and 81.64% to 108.10% with a standard deviation within 8.82% for FNT. The proposed method shows a potentially powerful capability for fast quantitative analysis of pesticide residues. PMID:23805266

  18. Chlorpyrifos inhibits cell proliferation through ERK1/2 phosphorylation in breast cancer cell lines.

    PubMed

    Ventura, Clara; Venturino, Andrés; Miret, Noelia; Randi, Andrea; Rivera, Elena; Núñez, Mariel; Cocca, Claudia

    2015-02-01

    It is well known the participation of oxidative stress in the induction and development of different pathologies including cancer, diabetes, neurodegeneration and respiratory disorders among others. It has been reported that oxidative stress may be induced by pesticides and it could be the cause of health alteration mediated by pollutants exposure. Large number of registered products containing chlorpyrifos (CPF) is used to control pest worldwide. We have previously reported that 50 μM CPF induces ROS generation and produces cell cycle arrest followed by cell death. The present investigation was designed to identify the pathway involved in CPF-inhibited cell proliferation in MCF-7 and MDA-MB-231 breast cancer cell lines. In addition, we determined if CPF-induced oxidative stress is related to alterations in antioxidant defense system. Finally we studied the molecular mechanisms underlying in the cell proliferation inhibition produced by the pesticide. In this study we demonstrate that CPF (50 μM) induces redox imbalance altering the antioxidant defense system in breast cancer cells. Furthermore, we found that the main mechanism involved in the inhibition of cell proliferation induced by CPF is an increment of p-ERK1/2 levels mediated by H2O2 in breast cancer cells. As PD98059 could not abolish the increment of ROS induced by CPF, we concluded that ERK1/2 phosphorylation is subsequent to ROS production induced by CPF but not the inverse. PMID:25180937

  19. A model of chlorpyrifos distribution and its biochemical effects on the liver and kidneys of rats.

    PubMed

    Tanvir, E M; Afroz, R; Chowdhury, Maz; Gan, S H; Karim, N; Islam, M N; Khalil, M I

    2016-09-01

    This study investigated the main target sites of chlorpyrifos (CPF), its effect on biochemical indices, and the pathological changes observed in rat liver and kidney function using gas chromatography/mass spectrometry. Adult female Wistar rats (n = 12) were randomly assigned into two groups (one control and one test group; n = 6 each). The test group received CPF via oral gavage for 21 days at 5 mg/kg daily. The distribution of CPF was determined in various organs (liver, brain, heart, lung, kidney, ovary, adipose tissue, and skeletal muscle), urine and stool samples using GCMS. Approximately 6.18% of CPF was distributed in the body tissues, and the highest CPF concentration (3.80%) was found in adipose tissue. CPF also accumulated in the liver (0.29%), brain (0.22%), kidney (0.10%), and ovary (0.03%). Approximately 83.60% of CPF was detected in the urine. CPF exposure resulted in a significant increase in plasma transaminases, alkaline phosphatase, and total bilirubin levels, a significant reduction in total protein levels and an altered lipid profile. Oxidative stress due to CPF administration was also evidenced by a significant increase in liver malondialdehyde levels. The detrimental effects of CPF on kidney function consisted of a significant increase in plasma urea and creatinine levels. Liver and kidney histology confirmed the observed biochemical changes. In conclusion, CPF bioaccumulates over time and exerts toxic effects on animals.

  20. Toxicity interaction between chlorpyrifos, mancozeb and soil moisture to the terrestrial isopod Porcellionides pruinosus.

    PubMed

    Morgado, Rui G; Gomes, Pedro A D; Ferreira, Nuno G C; Cardoso, Diogo N; Santos, Miguel J G; Soares, Amadeu M V M; Loureiro, Susana

    2016-02-01

    A main source of uncertainty currently associated with environmental risk assessment of chemicals is the poor understanding of the influence of environmental factors on the toxicity of xenobiotics. Aiming to reduce this uncertainty, here we evaluate the joint-effects of two pesticides (chlorpyrifos and mancozeb) on the terrestrial isopod Porcellionides pruinosus under different soil moisture regimes. A full factorial design, including three treatments of each pesticide and an untreated control, were performed under different soil moisture regimes: 25%, 50%, and 75% WHC. Our results showed that soil moisture had no effects on isopods survival, at the levels assessed in this experiment, neither regarding single pesticides nor mixture treatments. Additivity was always the most parsimonious result when both pesticides were present. Oppositely, both feeding activity and biomass change showed a higher sensitivity to soil moisture, with isopods generally showing worse performance when exposed to pesticides and dry or moist conditions. Most of the significant differences between soil moisture regimes were found in single pesticide treatments, yet different responses to mixtures could still be distinguished depending on the soil moisture assessed. This study shows that while soil moisture has the potential to influence the effects of the pesticide mixture itself, such effects might become less important in a context of complex combinations of stressors, as the major contribution comes from its individual interaction with each pesticide. Finally, the implications of our results are discussed in light of the current state of environmental risk assessment procedures and some future perspectives are advanced.

  1. The effect of chlorpyrifos on thermogenic capacity of bank voles selected for increased aerobic exercise metabolism.

    PubMed

    Dheyongera, Geoffrey; Grzebyk, Katherine; Rudolf, Agata M; Sadowska, Edyta T; Koteja, Paweł

    2016-04-01

    Agro-chemicals potentially cause adverse effects in non-target organisms. The rate of animal energy metabolism can influence their susceptibility to pesticides by influencing food consumption, biotransformation and elimination rates of toxicants. We used experimental evolution to study the effects of inherent differences in energy metabolism rate and exposure to the organophosphate insecticide, chlorpyrifos (CPF) on thermogenic capacity in a wild rodent, the bank vole (Myodes = Clethrionomys glareolus). The voles were sampled from four replicate lines selected for high swim-induced aerobic metabolism (A) and four unselected control (C) lines. Thermogenic capacity, measured as the maximum cold-induced rate of oxygen consumption (VO2cold), was higher in the A - than C lines, and it decreased after continuous exposure to CPF via food or after a single dose administered via oral gavage, but only when measured shortly after exposure. VO2cold measured 24 h after repeated exposure was not affected. In addition, gavage with a single dose led to decreased food consumption and loss in body mass. Importantly, the adverse effects of CPF did not differ between the selected and control lines. Therefore, exposure to CPF has adverse effects on thermoregulatory performance and energy balance in this species. The effects are short-lived and their magnitude is not associated with the inherent level of energy metabolism. Even without severe symptoms of poisoning, fitness can be compromised under harsh environmental conditions, such as cold and wet weather. PMID:26878110

  2. The health status of northern Omo State Farm workers exposed to chlorpyrifos and profenofos.

    PubMed

    Lakew, K; Mekonnen, Y

    1998-07-01

    The health effects of organophosphorus (OP) pesticides on cholinesterase (ChE) activities were assessed among 81 pest control workers from Northern Omo State Farm (Ethiopia), following the occupational use of Chlorpyrifos 25 and 48% ULV and Profenifos 250 EC/ULV. Plasma ChE (PChE) and erythrocyte ChE (AChE) activities were determined electrometrically before and after pesticide exposure. Plasma alkaline phosphatase (AP) and glutamic pyruvic transaminase (GPT) values were estimated colorimetrically. Risk factors of pesticide poisoning and related occupational factors were assessed following the WHO recommendations. The mean PChE and AChE activities determined after pesticide exposures were significantly lower than the pre-exposure values (P < 0.05); 16% and 40% of the pest control workers had PChE and AChE levels below 50% of the pre-exposure values, respectively. The mean plasma AP and GPT values were found to be within the recommended normal limits. No significant difference in either of the ChE activities was observed between the spray men and the pest assessors, although the former were believed to have frequent contact with the concentrated OP formulations. Risk factors of pesticide poisoning such as workers ignorance about the toxicity of pesticides, poor personal hygiene and total absence or improper use of personal protective devices were prevalent. Measures that should be considered to minimize the problem in the farm population are recommended. PMID:10214458

  3. Neurobehavioral and biochemical changes in Nauphoeta cinerea following dietary exposure to chlorpyrifos.

    PubMed

    Adedara, Isaac A; Rosemberg, Denis B; de Souza, Diego; Farombi, Ebenezer O; Aschner, Michael; Souza, Diogo O; Rocha, Joao B T

    2016-06-01

    The present study aimed to increase our understanding about the mode of toxic action of organophosphate pesticides in insects by evaluating the biochemical and neurobehavioral characteristics in Nauphoeta cinerea exposed to chlorpyrifos (CPF)-contaminated diet. The insects were exposed for 35 consecutive days to CPF at 0.078, 0.15625, 0.3125 and 0.625μg/g feed. Locomotor behavior was assessed for a 10-min trial in a novel arena and subsequently, biochemical analyses were carried out using the cockroaches' heads. In comparison to control, CPF-exposed cockroaches showed significant decreases in the total distance traveled, body rotation, turn angle and meandering, along with significant increase in the number of falls, time and episodes of immobility. The marked decrease in the exploratory profiles of CPF-exposed cockroaches was confirmed by track plots, whereas occupancy plot analyses showed a progressive dispersion at 0.15625μg/g feed group. Moreover, the heads of CPF-exposed cockroaches showed marked decrease in acetylcholinesterase activity and antioxidant status with concomitant significant elevation in dichlorofluorescein oxidation and lipid peroxidation levels in CPF-treated cockroaches. Gas Chromatography-Mass Spectrometry analyses revealed bioaccumulation of CPF in cockroaches exposed to concentrations above 0.078μg/g feed. The findings from this investigation showed N. cinerea as a value model organism for the risk assessment of environmental organophosphate contamination in insects. PMID:27155480

  4. Synergistic ameliorative effects of sesame oil and alpha-lipoic acid against subacute diazinon toxicity in rats: hematological, biochemical, and antioxidant studies.

    PubMed

    Abdel-Daim, Mohamed M; Taha, Ramadan; Ghazy, Emad W; El-Sayed, Yasser S

    2016-01-01

    Diazinon (DZN) is a common organophosphorus insecticide extensively used for agriculture and veterinary purposes. DZN toxicity is not limited to insects; it also induces harmful effects in mammals and birds. Our experiment evaluated the protective and antioxidant potential of sesame oil (SO) and (or) alpha-lipoic acid (ALA) against DZN toxicity in male Wistar albino rats. DZN-treated animals exhibited macrocytic hypochromic anemia and significant increases in serum biochemical parameters related to liver injury, including aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), γ-glutamyl transferase (γGT), cholesterol, and triglycerides. They also had elevated levels of markers related to cardiac injury, such as lactate dehydrogenase (LDH) and creatine phosphokinase (CPK), and increased biomarkers of renal injury, urea and creatinine. DZN also increased hepatic, renal, and cardiac lipid peroxidation and decreased antioxidant biomarker levels. SO and (or) ALA supplementation ameliorated the deleterious effects of DZN intoxication. Treatment improved hematology and serum parameters, enhanced endogenous antioxidant status, and reduced lipid peroxidation. Importantly, they exerted synergistic hepatoprotective, nephroprotective, and cardioprotective effects. Our findings demonstrate that SO and (or) ALA supplementation can alleviate the toxic effects of DZN via their potent antioxidant and free radical-scavenging activities.

  5. Simultaneous Determination of Parathion, Malathion, Diazinon, and Pirimiphos Methyl in Dried Medicinal Plants Using Solid-Phase Microextraction Fibre Coated with Single-Walled Carbon Nanotubes

    PubMed Central

    Ahmadkhaniha, Reza; Samadi, Nasrin; Salimi, Mona; Sarkhail, Parisa; Rastkari, Noushin

    2012-01-01

    A reliable and sensitive headspace solid-phase microextraction gas chromatography-mass spectrometry method for simultaneous determination of different organophosphorus pesticides in dried medicinal plant samples is described. The analytes were extracted by single-walled carbon nanotubes as a new solid-phase microextraction adsorbent. The developed method showed good performance. For diazinon and pirimiphos methyl calibration, curves were linear (r2 ≥ 0.993) over the concentration ranges from 1.5 to 300 ng g−1, and the limit of detection at signal-to-noise ratio of 3 was 0.3 ng g−1. For parathion and malathion, the linear range and limit of detection were 2.5–300 (r2 ≥ 0.991) and 0.5 ng g−1, respectively. In addition, a comparative study between the single-walled carbon nanotubes and a commercial polydimethylsiloxane fibre for the determination of target analytes was carried out. Single-walled carbon nanotubes fibre showed higher extraction capacity, better thermal stability (over 350°C), and longer lifespan (over 250 times) than the commercial polydimethylsiloxane fibre. The developed method was successfully applied to determine target organophosphorus pesticides in real samples. PMID:22645439

  6. Simultaneous determination of parathion, malathion, diazinon, and pirimiphos methyl in dried medicinal plants using solid-phase microextraction fibre coated with single-walled carbon nanotubes.

    PubMed

    Ahmadkhaniha, Reza; Samadi, Nasrin; Salimi, Mona; Sarkhail, Parisa; Rastkari, Noushin

    2012-01-01

    A reliable and sensitive headspace solid-phase microextraction gas chromatography-mass spectrometry method for simultaneous determination of different organophosphorus pesticides in dried medicinal plant samples is described. The analytes were extracted by single-walled carbon nanotubes as a new solid-phase microextraction adsorbent. The developed method showed good performance. For diazinon and pirimiphos methyl calibration, curves were linear (r(2) ≥ 0.993) over the concentration ranges from 1.5 to 300 ng g(-1), and the limit of detection at signal-to-noise ratio of 3 was 0.3 ng g(-1). For parathion and malathion, the linear range and limit of detection were 2.5-300 (r(2) ≥ 0.991) and 0.5 ng g(-1), respectively. In addition, a comparative study between the single-walled carbon nanotubes and a commercial polydimethylsiloxane fibre for the determination of target analytes was carried out. Single-walled carbon nanotubes fibre showed higher extraction capacity, better thermal stability (over 350 °C), and longer lifespan (over 250 times) than the commercial polydimethylsiloxane fibre. The developed method was successfully applied to determine target organophosphorus pesticides in real samples.

  7. Time-resolved fluorescence sensing of pesticides chlorpyrifos, crotoxyphos and endosulfan by the luminescent Eu(III)-8-allyl-3-carboxycoumarin probe.

    PubMed

    Azab, Hassan A; Khairy, Gasser M; Kamel, Rasha M

    2015-09-01

    This work describes the application of time resolved fluorescence in microtiter plates for investigating the interactions of europium-allyl-3-carboxycoumarin with pesticides chlorpyrifos, endosulfan and crotoxyphos. Stern-Volmer studies at different temperatures for chlorpyrifos and crotoxyphos shows dynamic and static quenching mechanisms respectively. Direct methods for the determination of the pesticides under investigation have been developed using the luminescence variations of the probe in solution. The detection limits are 6.53, 0.004, 3.72 μmol/L for chlorpyrifos, endosulfan, and crotoxyphos, respectively. The binding constants and thermodynamic parameters of the pesticides with probe were evaluated. A thermodynamic analysis showed that the reaction is spontaneous with negative ΔG. Effect of some relevant interferents on the detection of pesticides has been investigated. The new method was applied to the determination of the pesticides in different types of water samples (tap, mineral, and waste water).

  8. Determination of chlorpyrifos in air, leaves and soil from a greenhouse by gas-chromatography with nitrogen-phosphorus detection, high-performance liquid chromatography and capillary electrophoresis.

    PubMed

    Guardino, X; Obiols, J; Rosell, M G; Farran, A; Serra, C

    1998-10-01

    Chlorpyrifos was determined in air, leaves and soil in a greenhouse in order to establish performance differences between gas-chromatography with nitrogen-phosphorus detection (GC-NPD) and high-performance liquid chromatographic and capillary electrophoretic methods and to assess the farm workers' risk of overexposure due to air exposure and/or skin contact with this compound. Results obtained indicate that the three analytical techniques, with the specific procedures described, can be used, although only GC-NPD provides an operative limit of detection in air. Chlorpyrifos levels in air are dependent on time and greenhouse ventilation, whereas it remains for a long time on leaf surfaces and soil. As a consequence, specific instructions can be established for farm workers in order to avoid skin and respiratory exposure to chlorpyrifos.

  9. Time-resolved fluorescence sensing of pesticides chlorpyrifos, crotoxyphos and endosulfan by the luminescent Eu(III)-8-allyl-3-carboxycoumarin probe

    NASA Astrophysics Data System (ADS)

    Azab, Hassan A.; Khairy, Gasser M.; Kamel, Rasha M.

    2015-09-01

    This work describes the application of time resolved fluorescence in microtiter plates for investigating the interactions of europium-allyl-3-carboxycoumarin with pesticides chlorpyrifos, endosulfan and crotoxyphos. Stern-Volmer studies at different temperatures for chlorpyrifos and crotoxyphos shows dynamic and static quenching mechanisms respectively. Direct methods for the determination of the pesticides under investigation have been developed using the luminescence variations of the probe in solution. The detection limits are 6.53, 0.004, 3.72 μmol/L for chlorpyrifos, endosulfan, and crotoxyphos, respectively. The binding constants and thermodynamic parameters of the pesticides with probe were evaluated. A thermodynamic analysis showed that the reaction is spontaneous with negative ΔG. Effect of some relevant interferents on the detection of pesticides has been investigated. The new method was applied to the determination of the pesticides in different types of water samples (tap, mineral, and waste water).

  10. Down Syndrome: Cognitive Phenotype

    ERIC Educational Resources Information Center

    Silverman, Wayne

    2007-01-01

    Down syndrome is the most prevalent cause of intellectual impairment associated with a genetic anomaly, in this case, trisomy of chromosome 21. It affects both physical and cognitive development and produces a characteristic phenotype, although affected individuals vary considerably with respect to severity of specific impairments. Studies…

  11. Efficacies of spinosad and a combination of chlorpyrifos-methyl and deltamethrin against phosphine-resistant Rhyzopertha dominica (Coleoptera: Bostrichidae) and Tribolium castaneum (Coleoptera: Tenebrionidae) on wheat.

    PubMed

    Bajracharya, N S; Opit, George P; Talley, J; Jones, C L

    2013-10-01

    Highly phosphine-resistant populations of Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) and Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) have recently been found in Oklahoma grain storage facilities. These findings necessitate development of a phosphine resistance management strategy to ensure continued effective use of phosphine. Therefore, we investigated the efficacies of two grain insecticides, namely, spinosad applied at label rate of 1 ppm and a mixture of chlorpyrifos-methyl and deltamethrin applied at label rates of 3 and 0.5 ppm, respectively, against highly phosphine-resistant R. dominica and T. castaneum. Adult mortality and progeny production suppression of spinosad- or chlorpyrifos-methyl + deltamethrin mixture-treated wheat that had been stored for 2, 84, 168, 252, and 336 d posttreatment were assessed. We found that both spinosad and chlorpyrifos-methyl + deltamethrin were effective against phosphine-resistant R. dominica and caused 83-100% mortality and also caused total progeny production suppression for all storage periods. Spinosad was not effective against phosphine-resistant T. castaneum; the highest mortality observed was only 3% for all the storage periods. Chlorpyrifos-methyl + deltamethrin was effective against phosphine-resistant T. castaneum only in treated wheat stored for 2 and 84 d, where it caused 93-99% mortality. However, chlorpyrifos-methyl + deltamethrin was effective and achieved total suppression of progeny production in T. castaneum for all the storage periods. Spinosad was not as effective as chlorpyrifos-methyl + deltamethrin mixture at suppressing progeny production of phosphine-resistant T. castaneum. These two insecticides can be used in a phosphine resistance management strategy for R. dominica and T. castaneum in the United States.

  12. Urinary biomarker concentrations of captan, chlormequat, chlorpyrifos and cypermethrin in UK adults and children living near agricultural land.

    PubMed

    Galea, Karen S; MacCalman, Laura; Jones, Kate; Cocker, John; Teedon, Paul; Cherrie, John W; van Tongeren, Martie

    2015-01-01

    There is limited information on the exposure to pesticides experienced by UK residents living near agricultural land. This study aimed to investigate their pesticide exposure in relation to spray events. Farmers treating crops with captan, chlormequat, chlorpyrifos or cypermethrin provided spray event information. Adults and children residing ≤100 m from sprayed fields provided first-morning void urine samples during and outwith the spray season. Selected samples (1-2 days after a spray event and at other times (background samples)) were analysed and creatinine adjusted. Generalised Linear Mixed Models were used to investigate if urinary biomarkers of these pesticides were elevated after spray events. The final data set for statistical analysis contained 1518 urine samples from 140 participants, consisting of 523 spray event and 995 background samples which were analysed for pesticide urinary biomarkers. For captan and cypermethrin, the proportion of values below the limit of detection was greater than 80%, with no difference between spray event and background samples. For chlormequat and chlorpyrifos, the geometric mean urinary biomarker concentrations following spray events were 15.4 μg/g creatinine and 2.5 μg/g creatinine, respectively, compared with 16.5 μg/g creatinine and 3.0 μg/g creatinine for background samples within the spraying season. Outwith the spraying season, concentrations for chlorpyrifos were the same as those within spraying season backgrounds, but for chlormequat, lower concentrations were observed outwith the spraying season (12.3 μg/g creatinine). Overall, we observed no evidence indicative of additional urinary pesticide biomarker excretion as a result of spray events, suggesting that sources other than local spraying are responsible for the relatively low urinary pesticide biomarkers detected in the study population.

  13. Effects of a mixture of two insecticides in freshwater microcosms: I. Fate of chlorpyrifos and lindane and responses of macroinvertebrates.

    PubMed

    Cuppen, Jan G M; Crum, Steven J H; Van den Heuvel, Harry H; Smidt, Rob A; Van den Brink, Paul J

    2002-06-01

    Effects of chronic application of a mixture of the insecticides chlorpyrifos and lindane were studied in indoor freshwater microcosms. The exposure concentrations (based on 0, 0.005, 0.01, 0.05, 0.1 and 0.5 times the LC50 of the most sensitive standard test organism for each compound) were kept at a constant level for four weeks. The calculated mean concentrations for chlorpyrifos were found to be almost at their corresponding nominal level during the treatment period. The mean calculated lindane concentrations, however, were found to be 15-40% higher than intended. In the post treatment period both insecticides dissipated fast (t 1/2: chlorpyrifos 9 days, lindane 22 days) from the water phase. The concentrations of the mixture at the highest treatment level corresponded to 0.53 toxic units (TU) for Daphnia magna and 0.61 TU for the most sensitive fish. The decomposition of Populus leaves in litter bags was significantly lower at the three highest insecticide concentrations. The macroinvertebrate community was seriously affected at the three highest treatment levels, with Crustacea and the Chironomidae Corynoneura proving to be the most sensitive groups. Gastropoda and Oligochaeta were relatively insensitive and some taxa (e.g. Valvata piscinalis, juvenile Physa fontinalis, Nemertea and Stylaria lacustris) increased in numbers. The observed effects could be explained from the individual toxicity of the insecticides to the invertebrates, and did not indicate synergistic effects. A second paper (Van den Brink et al., 2002) addresses the effects on other endpoints, as well as the overall risk assessment of the insecticide mixture.

  14. The distribution of chlorpyrifos following a crack and crevice type application in the US EPA Indoor Air Quality Research House

    NASA Astrophysics Data System (ADS)

    Stout, D. M.; Mason, M. A.

    A study was conducted in the US EPA Indoor Air Quality (IAQ) Research House to determine the spatial and temporal distribution of chlorpyrifos following a professional crack and crevice application in the kitchen. Following the application, measurements were made in the kitchen, den and master bedroom over 21 days. Airborne concentrations were collected using both polyurethane foam (PUF) and the OSHA versatile sampler composed of XAD and PUF media located in tandem. Measured airborne concentrations were similar for the two samplers and were higher in the three rooms following the application. The highest measured concentrations were reached during the initial 24-h following application; concentrations subsequently declined over the 21-day study period to levels slightly above background. Spatial and temporal distributions onto surfaces were measured using 10-cm 2 rayon deposition coupons located on the floor. Sections were cut from existing carpet to determine the total extractable residues. Chlorpyrifos was measured from all matrixes in the kitchen, den and bedroom and the data shows the transport of airborne residues from the point of application to remote locations in the house. The findings are compared and discussed relative to another study conducted in which total release aerosols containing chlorpyrifos were activated in the IAQ research house and the resulting distributions evaluated. For both studies dose estimates were constructed for the exposure pathways using the Stochastic Human Exposure and Dose Estimation Model for pesticides. The United States Environmental Protection Agency has been mandated to examine children's exposure to environmental pollutants such as pesticides. This research specifically reduces uncertainties associated with estimating children's potential exposures to residentially applied pesticides and provides inputs to further evaluate and validate residential exposure models which might be used to reduce exposures and perform risk

  15. Comparative effects of parathion and chlorpyrifos on extracellular endocannabinoid levels in rat hippocampus: Influence on cholinergic toxicity

    SciTech Connect

    Liu, Jing; Parsons, Loren; Pope, Carey

    2013-11-01

    Parathion (PS) and chlorpyrifos (CPF) are organophosphorus insecticides (OPs) that elicit acute toxicity by inhibiting acetylcholinesterase (AChE). Endocannabinoids (eCBs, N-arachidonoylethanolamine, AEA; 2-arachidonoylglycerol, 2AG) can modulate neurotransmission by inhibiting neurotransmitter release. We proposed that differential inhibition of eCB-degrading enzymes (fatty acid amide hydrolase, FAAH, and monoacylglycerol lipase, MAGL) by PS and CPF leads to differences in extracellular eCB levels and toxicity. Microdialysis cannulae were implanted into hippocampus of adult male rats followed by treatment with vehicle (peanut oil, 2 ml/kg, sc), PS (27 mg/kg) or CPF (280 mg/kg) 6–7 days later. Signs of toxicity, AChE, FAAH and MAGL inhibition, and extracellular levels of AEA and 2AG were measured 2 and 4 days later. Signs were noted in PS-treated rats but not in controls or CPF-treated rats. Cholinesterase inhibition was extensive in hippocampus with PS (89–90%) and CPF (78–83%) exposure. FAAH activity was also markedly reduced (88–91%) by both OPs at both time-points. MAGL was inhibited by both OPs but to a lesser degree (35–50%). Increases in extracellular AEA levels were noted after either PS (about 2-fold) or CPF (about 3-fold) while lesser treatment-related 2-AG changes were noted. The cannabinoid CB1 receptor antagonist/inverse agonist AM251 (3 mg/kg, ip) had no influence on functional signs after CPF but markedly decreased toxicity in PS-treated rats. The results suggest that extracellular eCBs levels can be markedly elevated by both PS and CPF. CB1-mediated signaling appears to play a role in the acute toxicity of PS but the role of eCBs in CPF toxicity remains unclear. - Highlights: • Chlorpyrifos and parathion both extensively inhibited hippocampal cholinesterase. • Functional signs were only noted with parathion. • Chlorpyrifos and parathion increased hippocampal extracellular anandamide levels. • 2-Arachidonoylglycerol levels were

  16. Protective effects of curcumin and vitamin E against chlorpyrifos-induced lung oxidative damage.

    PubMed

    Hassani, S; Sepand, M R; Jafari, A; Jaafari, J; Rezaee, R; Zeinali, M; Tavakoli, F; Razavi-Azarkhiavi, K

    2015-06-01

    There are increasing concerns regarding the toxic effects of chlorpyrifos (CPF) on human health. Curcumin (CUR) is a yellow pigment isolated from turmeric ground rhizome of Curcuma longa Linn., which has been identified as an antioxidant agent. This study was designed to examine the protective effect of CUR and vitamin E (Vit E) on CPF-induced lung toxicity. Rats were divided into seven groups: control, CPF (13.5 mg/kg, orally), CPF + CUR (100 and 300 mg/kg, respectively, orally), CPF + α-tocopherol (Vit E, 150 mg/kg, intraperitoneally), CPF and CUR (100 and 300 mg/kg, respectively) in combination with α-tocopherol. The regimens were administered once daily for 28 days. At the end of the treatment period, lungs were collected for evaluation of oxidative factors and histopathological parameters. CUR and Vit E led to a decrease in lipid peroxidation in the lungs of the CPF-injected animals (48% and 51%, respectively). Glutathione peroxidase inhibited by CPF (91.9 nmol/min/mg protein) was induced again by CUR and Vit E (167.1 and 171.8 nmol/min/mg protein). CUR and Vit E caused a significant induction of superoxide dismutase (103.4 U/mg protein). Catalase activity almost returned to normalcy in CPF-intoxicated rats subjected to CUR + Vit E treatment (p < 0.001). Lung sections from CPF-treated rats displayed histopathological damages, while coadministration of CUR and Vit E resulted in apparently normal morphology with a significant decrease in injuries (p < 0.05). Our findings revealed that coadministration of Vit E and CUR to CPF-treated animals prevents the oxidative damages in the lung tissues. PMID:25233897

  17. Biotreatment of chlorpyrifos in a bench scale bioreactor using Psychrobacter alimentarius T14.

    PubMed

    Khalid, Saira; Hashmi, Imran

    2016-01-01

    Bacteria tolerant to high pesticide concentration could be used for designing an efficient treatment technology. Bacterial strains T14 was isolated from pesticide-contaminated soil in mineral salt medium (MSM) and identified as Psychrobacter alimentarius T14 using 16S rRNA gene sequence analysis. Bench scale bioreactor was evaluated for biotreatment of high Chlorpyrifos (CP) concentration using P. alimentarius T14. Effect of various parameters on bioreactor performance was examined and optimum removal was observed at optical density (OD600 nm): 0.8; pH: 7.2; CP concentration: 300 mg L(-1) and hydraulic retention time: 48 h. At optimum conditions, 70.3/79% of CP/chemical oxygen demand (COD) removal was achieved in batch bioreactors. In addition, P. alimentarius T14 achieved 95/91, 62.3/75, 69.8/64% CP/COD removal efficiency with addition of CS (co-substrates), CS1 (yeast extract + synthetic wastewater), CS2 (glucose + synthetic wastewater) and CS3 (yeast extract), respectively. Addition of CS1 to bioreactor could accelerate CP removal rate up to many cycles with considerable efficiency. However, accumulation of 3, 5, 6-trichloro-2-pyridinol affects reactor performance in cyclic mode. First-order rate constant k1 0.062 h(-1) and t1/2 11.1 h demonstrates fast degradation. Change in concentration of total chlorine and nitrogen could be the result of complete mineralization. Photodegradation of CP in commercial product was more than its pure form. Commercial formulation accelerated photodegradation process; however no effect on biodegradation process was observed. After bio-photodegradation, negligible toxicity for seeds of Triticum aestivum was observed. Study suggests an efficient treatment of wastewater containing CP and its metabolites in batch bioreactors could be achieved using P. alimentarius. PMID:26144866

  18. Mitochondrial dysfunction in aging rat brain regions upon chlorpyrifos toxicity and cold stress: an interactive study.

    PubMed

    Basha, P Mahaboob; Poojary, Annappa

    2014-07-01

    Mitochondrial dysfunction and consequent energy depletion are the major causes of oxidative stress resulting to bring alterations in the ionic homeostasis causing loss of cellular integrity. Our previous studies have shown the age-associated interactive effects in rat central nervous system (CNS) upon co-exposure to chlorpyrifos (CPF) and cold stress leading to macromolecular oxidative damage. The present study elucidates a possible mechanism by which CPF and cold stress interaction cause(s) mitochondrial dysfunction in an age-related manner. In this study, the activity levels of Krebs cycle enzymes and electron transport chain (ETC) protein complexes were assessed in the isolated fraction of mitochondria. CPF and cold stress (15 and 20 °C) exposure either individually or in combination decreased the activity level of Krebs cycle enzymes and ETC protein complexes in discrete regions of rat CNS. The findings confirm that cold stress produces significant synergistic effect in CPF intoxicated aging rats. The synergism between CPF and cold stress at 15 °C caused a higher depletion of respiratory enzymes in comparison with CPF and cold stress alone and together at 20 °C indicating the extent of deleterious functional alterations in discrete regions of brain and spinal cord (SC) which may result in neurodegeneration and loss in neuronal metabolic control. Hence, co-exposure of CPF and cold stress is more dangerous than exposure of either alone. Among the discrete regions studied, the cerebellum and medulla oblongata appears to be the most susceptible regions when compared to cortex and SC. Furthermore, the study reveals a gradual decrease in sensitivity to CPF toxicity as the rat matures.

  19. Toxicogenomic profiling in maternal and fetal rodent brains following gestational exposure to chlorpyrifos

    SciTech Connect

    Moreira, Estefania G.; Yu Xiaozhong; Robinson, Joshua F.; Griffith, Willian; Hong, Sung Woo; Beyer, Richard P.; Bammler, Theo K.; Faustman, Elaine M.

    2010-06-15

    Considering the wide variety of effects that have been reported to occur in the developmental neurotoxicity of chlorpyrifos (CP) and the lack of consensus on their dependence of brain acetylcholinesterase (AChE) activity inhibition, we applied microarray technology to explore dose-dependent alterations in transcriptional response in the fetal and maternal C57BL/6 mouse brain after daily gestational exposure (days 6 to 17) to CP (2, 4, 10, 12 or 15 mg/kg, sc). We identified significantly altered genes across doses and assessed for overrepresentation of Gene Ontology (GO) biological processes and KEGG pathways. We further clustered genes based on their expression profiles across doses and repeated the GO/pathways analysis for each cluster. The dose-effect relationship of CP on gene expression, both at the gene and pathway levels was non-monotonic and not necessarily related to brain AChE inhibition. The largest impact was observed in the 10 mg/kg dose group which was also the LOAEL for brain AChE inhibition. In the maternal brain, lower doses (4 mg/kg) influenced GO categories and pathways such as cell adhesion, behavior, lipid metabolism, long-term potentiation, nervous system development, neurogenesis, synaptic transmission. In the fetal brain, lower doses (2 and/or 4 mg/kg) significantly altered cell division, translation, transmission of nerve impulse, chromatin modification, long-term potentiation. In addition, some genes involved in nervous system development and signaling were shown to be specifically influenced by these lower CP doses. Our approach was sensitive and reflected the diversity of responses known to be disrupted by CP and highlighted possible additional consequences of CP neurotoxicity, such as disturbance of the ubiquitin proteasome system.

  20. Influence of different formulations on chlorpyrifos behavior and risk assessment in bamboo forest of China.

    PubMed

    Liu, Yihua; Mo, Runhong; Tang, Fubin; Fu, Yan; Guo, Yirong

    2015-12-01

    The effects of two formulations (emulsifiable concentrate (EC) and granule (G)) on the distribution, degradation, sorption, and residue risk of chlorpyrifos (CHP) were investigated in two producing areas of bamboo shoot. The results showed that CHP was mainly distributed in the topsoil (0-5 cm, P < 0.05), with the proportion of CHP in the total quantity ranging from 76.0 to 100.0 % (G) and 12.0 to 98.1 % (EC), respectively. The degradation of CHP-EC in soils (half-life 27.7-36.4 days) was faster than that of CHP-G in soils (half life above 120-150 days). The main metabolite of CHP, 3,5,6-trichloro-2-pyridinol (TCP), was found in soil samples. CHP showed good sorption ability in the two tested soils, with the sorption coefficient (KF) of 43.76 and 94.43 mg/kg. The terminal residues of CHP in bamboo shoots were in the range of 15.2-75.6 (G) and 10.4-35.7 μg/kg (EC), respectively. The soil type had a notable effect on the CHP behaviors in soil (P < 0.05, especially for CHP-G), but it did not affect the metabolite of CHP. Although some positive bamboo shoot samples (CHP residue exceeding maximum residue limits) were found, the hazard quotients did not exceed 7 %, which meant there was a negligible risk associated with the exposure to CHP via the consumption of bamboo shoots. PMID:26308925

  1. Carnosic Acid Affords Mitochondrial Protection in Chlorpyrifos-Treated Sh-Sy5y Cells.

    PubMed

    de Oliveira, Marcos Roberto; Peres, Alessandra; Ferreira, Gustavo Costa; Schuck, Patrícia Fernanda; Bosco, Simone Morelo Dal

    2016-10-01

    Carnosic acid (CA; C20H28O4) is a phenolic diterpene found in rosemary (Rosmarinus officinalis L.) and exhibits protective properties, e.g., antioxidant, anti-inflammatory, antitumor, and antimicrobial activities. In this context, CA has been viewed as a neuroprotective agent due to its ability in rescuing neuronal cells from pro-oxidant and pro-apoptotic challenges. In the present work, we found that CA pretreatment at 1 µM for 12 h suppressed the mitochondria-related pro-oxidant and mitochondria-dependent pro-apoptotic effects of chlorpyrifos (CPF) in human neuroblastoma SH-SY5Y cells. CA prevented mitochondrial membrane potential disruption and decreased the levels of oxidative stress markers in mitochondrial membranes obtained from cells exposed to CPF. CA also inhibited cytochrome c release and activation of the caspases-9 and -3, as well as decreased DNA fragmentation, in CPF-treated cells. CA upregulated the content of glutathione (GSH) in mitochondria by a mechanism involving the activation of the phosphoinositide-3-kinase (PI3K)/Akt/nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway, since inhibition of PI3K/Akt or silencing of Nrf2 using siRNA strategy abolished the protection exerted by CA in SH-SY5Y cells. Therefore, CA protected mitochondria of SH-SY5Y cells through the activation of the PI3K/Akt/Nrf2 axis, causing upregulation of the mitochondrial GSH content and consequent antioxidant and anti-apoptotic effects. PMID:27083155

  2. Evaluation of Epidemiology and Animal Data for Risk Assessment: Chlorpyrifos Developmental Neurobehavioral Outcomes

    PubMed Central

    Li, Abby A.; Lowe, Kimberly A.; McIntosh, Laura J.; Mink, Pamela J.

    2012-01-01

    Developmental neurobehavioral outcomes attributed to exposure to chlorpyrifos (CPF) obtained from epidemiologic and animal studies published before June 2010 were reviewed for risk assessment purposes. For epidemiological studies, this review considered (1) overall strength of study design, (2) specificity of CPF exposure biomarkers, (3) potential for bias, and (4) Hill guidelines for causal inference. In the case of animal studies, this review focused on evaluating the consistency of outcomes for developmental neurobehavioral endpoints from in vivo mammalian studies that exposed dams and/or offspring to CPF prior to weaning. Developmental neuropharmacologic and neuropathologic outcomes were also evaluated. Experimental design and methods were examined as part of the weight of evidence. There was insufficient evidence that human developmental exposures to CPF produce adverse neurobehavioral effects in infants and children across different cohort studies that may be relevant to CPF exposure. In animals, few behavioral parameters were affected following gestational exposures to 1 mg/kg-d but were not consistently reported by different laboratories. For postnatal exposures, behavioral effects found in more than one study at 1 mg/kg-d were decreased errors on a radial arm maze in female rats and increased errors in males dosed subcutaneously from postnatal day (PND) 1 to 4. A similar finding was seen in rats exposed orally from PND 1 to 21 with incremental dose levels of 1, 2, and 4 mg/kg-d, but not in rats dosed with constant dose level of 1 mg/kg-d. Neurodevelopmental behavioral, pharmacological, and morphologic effects occurred at doses that produced significant brain or red blood cell acetylcholinesterase inhibition in dams or offspring. PMID:22401178

  3. Variability in the dynamics of mortality and immobility responses of freshwater arthropods exposed to chlorpyrifos.

    PubMed

    Rubach, Mascha N; Crum, Steven J H; Van den Brink, Paul J

    2011-05-01

    The species sensitivity distribution (SSD) concept is an important probabilistic tool for environmental risk assessment (ERA) and accounts for differences in species sensitivity to different chemicals. The SSD model assumes that the sensitivity of the species included is randomly distributed. If this assumption is violated, indicator values, such as the 50% hazardous concentration, can potentially change dramatically. Fundamental research, however, has discovered and described specific mechanisms and factors influencing toxicity and sensitivity for several model species and chemical combinations. Further knowledge on how these mechanisms and factors relate to toxicologic standard end points would be beneficial for ERA. For instance, little is known about how the processes of toxicity relate to the dynamics of standard toxicity end points and how these may vary across species. In this article, we discuss the relevance of immobilization and mortality as end points for effects of the organophosphate insecticide chlorpyrifos on 14 freshwater arthropods in the context of ERA. For this, we compared the differences in response dynamics during 96 h of exposure with the two end points across species using dose response models and SSDs. The investigated freshwater arthropods vary less in their immobility than in their mortality response. However, differences in observed immobility and mortality were surprisingly large for some species even after 96 h of exposure. As expected immobility was consistently the more sensitive end point and less variable across the tested species and may therefore be considered as the relevant end point for population of SSDs and ERA, although an immobile animal may still potentially recover. This is even more relevant because an immobile animal is unlikely to survive for long periods under field conditions. This and other such considerations relevant to the decision-making process for a particular end point are discussed.

  4. Long-Term Effects on Hypothalamic Neuropeptides after Developmental Exposure to Chlorpyrifos in Mice

    PubMed Central

    Tait, Sabrina; Ricceri, Laura; Venerosi, Aldina; Maranghi, Francesca; Mantovani, Alberto; Calamandrei, Gemma

    2009-01-01

    Background Increasing evidence from animal and human studies indicates that chlorpyrifos (CPF), similar to other organophosphorus insecticides still widely used, is a developmental neurotoxicant. Developmental exposure to CPF in rodents induces sex-dimorphic behavioral changes at adulthood, including social and agonistic responses, which suggests that CPF may interfere with maturation of neuroendocrine mechanisms. Objectives We assessed the hypothesis that CPF affects the levels of neurohypophyseal hormones acting as modulators of social behavior in mammals, such as oxytocin (OT), arginine vasopressin (AVP), and prolactin (PRL). Methods Pregnant female mice were orally administered with either vehicle (peanut oil) or 3 or 6 mg/kg CPF on gestational day (GD) 15 to GD18, and offspring were treated subcutaneously with either vehicle or 1 or 3 mg/kg CPF on postnatal days (PNDs) 11 to PND14. Dose levels were chosen to avoid systemic toxicity and inhibition of brain acetylcholinesterase. Offspring were sacrificed at 5 months of age, and expression of OT, AVP, and PRL was analyzed in the hypothalamus by Western blot or enzyme-linked immunosorbent assay (ELISA) analysis. Results Both male and female mice showed dose-related enhancement of OT expression, with males presenting the more intense effect. AVP expression was significantly reduced in male mice at the higher prenatal and postnatal dose. We observed no significant effect on PRL expression in either sex. Overall, outcomes were mainly attributable to fetal exposure, whereas postnatal doses appeared to potentiate the prenatal effects. Conclusions Our data indicate that developmental exposure to CPF may permanently interfere with specific key signaling proteins of the hypothalamic peptidergic system, with time-, dose-, and sex-related effects still evident at adulthood. PMID:19165396

  5. Chronic dietary chlorpyrifos causes long-term spatial memory impairment and thigmotaxic behavior.

    PubMed

    López-Granero, Caridad; Ruiz-Muñoz, Ana M; Nieto-Escámez, Francisco A; Colomina, María T; Aschner, Michael; Sánchez-Santed, Fernando

    2016-03-01

    Little is known about the long-term effects of chronic exposure to low-level organophosphate (OP) pesticides, and the role of neurotransmitter systems, other than the cholinergic system, in mediating OP neurotoxicity. In this study, rats were administered 5mg/kg/day of chlorpyrifos (CPF) for 6 months commencing at 3-months-of-age. The animals were examined 7 months later (at 16-months-of-age) for spatial learning and memory in the Morris water maze (MWM) and locomotor activity. In addition, we assessed the chronic effects of CPF on glutamatergic and gamma-aminobutyric acid (GABAergic) function using pharmacological challenges with dizocilpine (MK801) and diazepam. Impaired performance related to altered search patterns, including thigmotaxis and long-term spatial memory was noted in the MWM in animals exposed to CPF, pointing to dietary CPF-induced behavioral disturbances, such as anxiety. Twenty-four hours after the 31st session of repeated acquisition task, 0.1mg/kg MK801, an N-methyl-d-aspartate (NMDA) antagonist was intraperitoneally (i.p.) injected for 4 consecutive days. Decreased latencies in the MWM in the control group were noted after two sessions with MK801 treatment. Once the MWM assessment was completed, animals were administered 0.1 or 0.2mg/kg of MK801 and 1 or 3mg/kg of diazepam i.p., and tested for locomotor activity. Both groups, the CPF dietary and control, displayed analogous performance in motor activity. In conclusion, our data point to a connection between the long-term spatial memory, thigmotaxic response and CPF long after the exposure ended.

  6. Comparative Pharmacokinetics of Chlorpyrifos versus its Major Metabolites Following Oral Administration in the Rat

    SciTech Connect

    Busby-Hjerpe, Andrea L.; Campbell, James A.; Smith, Jordan N.; Lee, Sookwang; Poet, Torka S.; Barr, Dana; Timchalk, Charles

    2010-01-31

    Chlorpyrifos (CPF) is a commonly used diethylphosphorothionate organophosphorus (OP) insecticide. Diethylphosphate (DEP), diethylthiophosphate (DETP) and 3,5,6-trichloro-2-pyridinol (TCPy) are products of in vivo metabolism and environmental degradation of CPF and are routinely measured in urine as biomarkers of exposure. Hence, urinary biomonitoring of TCPy, DEP and DETP may be reflective of an individual’s contact with both the parent pesticide and exposure to these metabolites. In the current study, simultaneous dosing of 13C- or 2H- isotopically labeled CPF (13Clabeled CPF, 5 13C on the TCPy ring; or 2H-labeled CPF, diethyl-D10 (deuterium labeled) on the side chain) were exploited to directly compare the pharmacokinetics and metabolism of CPF with TCPy, and DETP. Individual metabolites were co-administered (oral gavage) with the parent compound at equal molar doses (14 μmol/kg; ~5mg/kg CPF). The key objective in the current study was to quantitatively evaluate the pharmacokinetics of the individual metabolites relative to their formation following a dose of CPF. Major differences in the pharmacokinetics between CPF and metabolites doses were observed within the first 3 h of exposure, due to the required metabolism of CPF to initially form TCPy and DETP. Nonetheless, once a substantial amount of CPF has been metabolized (≥ 3 h post-dosing) pharmacokinetics for both treatment groups and metabolites were very comparable. Urinary excretion rates for orally administered TCPy and DETP relative to 13C-CPF or 2H-CPF derived 13C-TCPy and 2H-DETP were consistent with blood pharmacokinetics, and the urinary clearance of metabolite dosed groups were comparable with the results for the 13C- and 2H-CPF groups. Since the pharmacokinetics of the individual metabolites were not modified by co-exposure to 3 CPF; it suggests that environmental exposure to low dose mixtures of pesticides and metabolites will not impact the pharmacokinetics of either.

  7. Fluorescent Chemosensors for Selective and Sensitive Detection of Phosmet/Chlorpyrifos with Octahedral Ni(2+) Complexes.

    PubMed

    Raj, Pushap; Singh, Amanpreet; Kaur, Kamalpreet; Aree, Thammarat; Singh, Ajnesh; Singh, Narinder

    2016-05-16

    The hexadentate ligands H2L1-L3 with mixed S, N, O donor sites and possessing substituents having either "no" or electron-releasing/withdrawing nature at terminal ends are synthesized. The ligands H2L1-L3 were tested for binding with library of metal ions, wherein maximum efficiency was observed with Ni(2+), and it motivated us to prepare the Ni(2+) complexes. The ligand H2L1 underwent deprotonation and formed binuclear complex when interacted with Ni(2+) as evident from its crystal structure. The H2L2 and H2L3 having electron-withdrawing/electron releasing groups, respectively, were also deprotonated; however, they afforded mononuclear complexes with Ni(2+) ion. This signifies the importance of steric parameters instead of electronic factors in these particular cases. Impressed by differential behavior of complexes of H2L1 and H2L2/H2L3 with Ni(2+) and their photophysical and electrochemical properties, all the metal complexes were studied for their chemosensing ability. Nowadays with increased use of organophosphate, there is alarming increase of these agents in the environment, and thus we require efficient technique to estimate the level of these agents with high sensitivity and selectivity in aqueous medium. The Ni(2+) complexes with hydrophobic nature were suspended into aqueous medium for testing them as sensor for organophosphate. The (L1)2.(Ni(2+))2 could sense phosmet with detection limit of 44 nM, whereas L2.Ni(2+) and L3.Ni(2+) exhibited the detection limits of 62 and 71 nM, respectively, for chlorpyrifos.

  8. Biomarkers of Chlorpyrifos Exposure and Effect in Egyptian Cotton Field Workers

    PubMed Central

    Farahat, Fayssal M.; Ellison, Corie A.; Bonner, Matthew R.; McGarrigle, Barbara P.; Crane, Alice L.; Fenske, Richard A.; Lasarev, Michael R.; Rohlman, Diane S.; Anger, W. Kent; Lein, Pamela J.; Olson, James R.

    2011-01-01

    Background Chlorpyrifos (CPF), a widely used organophosphorus pesticide (OP), is metabolized to CPF-oxon, a potent cholinesterase (ChE) inhibitor, and trichloro-2-pyridinol (TCPy). Urinary TCPy is often used as a biomarker for CPF exposure, whereas blood ChE activity is considered an indicator of CPF toxicity. However, whether these biomarkers are dose related has not been studied extensively in populations with repeated daily OP exposures. Objective We sought to determine the relationship between blood ChE and urinary TCPy during repeated occupational exposures to CPF. Methods Daily urine samples and weekly blood samples were collected from pesticide workers (n = 38) in Menoufia Governorate, Egypt, before, during, and after 9–17 consecutive days of CPF application to cotton fields. We compared blood butyrylcholinesterase (BuChE) and acetylcholinesterase (AChE) activities with the respective urinary TCPy concentrations in each worker. Results Average TCPy levels during the middle of a 1- to 2-week CPF application period were significantly higher in pesticide applicators (6,437 μg/g creatinine) than in technicians (184 μg/g) and engineers (157 μg/g), both of whom are involved in supervising the application process. We observed a statistically significant inverse correlation between urinary TCPy and blood BuChE and AChE activities. The no-effect level (or inflection point) of the exposure–effect relationships has an average urinary TCPy level of 114 μg/g creatinine for BuChE and 3,161 μg/g creatinine for AChE. Conclusions Our findings demonstrate a dose–effect relationship between urinary TCPy and both plasma BuChE and red blood cell AChE in humans exposed occupationally to CPF. These findings will contribute to future risk assessment efforts for CPF exposure. PMID:21224175

  9. Influence of different formulations on chlorpyrifos behavior and risk assessment in bamboo forest of China.

    PubMed

    Liu, Yihua; Mo, Runhong; Tang, Fubin; Fu, Yan; Guo, Yirong

    2015-12-01

    The effects of two formulations (emulsifiable concentrate (EC) and granule (G)) on the distribution, degradation, sorption, and residue risk of chlorpyrifos (CHP) were investigated in two producing areas of bamboo shoot. The results showed that CHP was mainly distributed in the topsoil (0-5 cm, P < 0.05), with the proportion of CHP in the total quantity ranging from 76.0 to 100.0 % (G) and 12.0 to 98.1 % (EC), respectively. The degradation of CHP-EC in soils (half-life 27.7-36.4 days) was faster than that of CHP-G in soils (half life above 120-150 days). The main metabolite of CHP, 3,5,6-trichloro-2-pyridinol (TCP), was found in soil samples. CHP showed good sorption ability in the two tested soils, with the sorption coefficient (KF) of 43.76 and 94.43 mg/kg. The terminal residues of CHP in bamboo shoots were in the range of 15.2-75.6 (G) and 10.4-35.7 μg/kg (EC), respectively. The soil type had a notable effect on the CHP behaviors in soil (P < 0.05, especially for CHP-G), but it did not affect the metabolite of CHP. Although some positive bamboo shoot samples (CHP residue exceeding maximum residue limits) were found, the hazard quotients did not exceed 7 %, which meant there was a negligible risk associated with the exposure to CHP via the consumption of bamboo shoots.

  10. Biotreatment of chlorpyrifos in a bench scale bioreactor using Psychrobacter alimentarius T14.

    PubMed

    Khalid, Saira; Hashmi, Imran

    2016-01-01

    Bacteria tolerant to high pesticide concentration could be used for designing an efficient treatment technology. Bacterial strains T14 was isolated from pesticide-contaminated soil in mineral salt medium (MSM) and identified as Psychrobacter alimentarius T14 using 16S rRNA gene sequence analysis. Bench scale bioreactor was evaluated for biotreatment of high Chlorpyrifos (CP) concentration using P. alimentarius T14. Effect of various parameters on bioreactor performance was examined and optimum removal was observed at optical density (OD600 nm): 0.8; pH: 7.2; CP concentration: 300 mg L(-1) and hydraulic retention time: 48 h. At optimum conditions, 70.3/79% of CP/chemical oxygen demand (COD) removal was achieved in batch bioreactors. In addition, P. alimentarius T14 achieved 95/91, 62.3/75, 69.8/64% CP/COD removal efficiency with addition of CS (co-substrates), CS1 (yeast extract + synthetic wastewater), CS2 (glucose + synthetic wastewater) and CS3 (yeast extract), respectively. Addition of CS1 to bioreactor could accelerate CP removal rate up to many cycles with considerable efficiency. However, accumulation of 3, 5, 6-trichloro-2-pyridinol affects reactor performance in cyclic mode. First-order rate constant k1 0.062 h(-1) and t1/2 11.1 h demonstrates fast degradation. Change in concentration of total chlorine and nitrogen could be the result of complete mineralization. Photodegradation of CP in commercial product was more than its pure form. Commercial formulation accelerated photodegradation process; however no effect on biodegradation process was observed. After bio-photodegradation, negligible toxicity for seeds of Triticum aestivum was observed. Study suggests an efficient treatment of wastewater containing CP and its metabolites in batch bioreactors could be achieved using P. alimentarius.

  11. Ultraviolet Photolysis of Chlorpyrifos: Developmental Neurotoxicity Modeled in PC12 Cells

    PubMed Central

    Slotkin, Theodore A.; Seidler, Frederic J.; Wu, Changlong; MacKillop, Emiko A.; Linden, Karl G.

    2009-01-01

    Background Ultraviolet photodegradation products from pesticides form both in the field and during water treatment. Objectives We evaluated the photolytic breakdown of the organophosphate pesticide chlorpyrifos (CPF) in terms of both the chemical entities generated by low-pressure ultraviolet C irradiation and their potential as developmental neurotoxicants. Methods We separated by-products using high-performance liquid chromatography and characterized them by gas chromatography/mass spectrometry. We assessed neurotoxicity in neuronotypic PC12 cells, both in the undifferentiated state and during differentiation. Results Photodegradation of CPF in methanol solution generated CPF oxon and trichloropyridinol, products known to retain developmental neurotoxicant actions, as well as a series of related organophosphate and phosphorothionate derivatives. Exposure conditions that led to 50% degradation of CPF thus did not reduce developmental neurotoxicity. The degradation mixture inhibited DNA synthesis in undifferentiated cells to the same extent as native CPF. In differentiating cells, the products likewise retained the full ability to elicit shortfalls in cell number and corresponding effects on cell growth and neurite formation. When the exposure was prolonged to the point where 70% of the CPF was degraded, the adverse effects on PC12 cells were no longer evident; however, these conditions were sufficiently severe to generate toxic products from the methanol vehicle. Conclusions Our results indicate that field conditions or remediation treatments that degrade a significant proportion of the CPF do not necessarily produce inactive products and, indeed, may elicit formation of even more toxic chemicals that are more water soluble and thus have greater field mobility than CPF itself. PMID:19337505

  12. Effects of exercise conditioning on thermoregulatory responses to repeated administration of chlorpyrifos.

    PubMed

    Rowsey, Pamela Johnson; Metzger, Bonnie L; Carlson, John; Gordon, Christopher J

    2003-05-01

    Little is known about the effects of physical activity (i.e., exercise training) on susceptibility to environmental toxicants. Chlorpyrifos (CHP), an organophosphate (OP) insecticide, affects thermoregulation, causing an acute period of hypothermia followed by a delayed fever. Since exercise conditioning alters the thermoregulatory responses of rodents, this study examined whether exercise training would alter the thermoregulatory response to repeated CHP administration in the female Sprague-Dawley rat. Core temperature (T(c)) and motor activity (MA) were monitored by radiotelemetry in rats housed at an ambient temperature (T(a)) of 22 degrees C. The rats either were provided with continuous access to running wheels (exercise group) or were housed in standard cages without wheels (sedentary group). The exercise group rats ran predominantly at night with an average of 7.6 km/24h. After 8 weeks the rats in both groups were gavaged daily with corn oil or 10mg/kg CHP (dissolved in corn oil) for 4 days. CHP induced an immediate hypothermic response followed by a delayed fever throughout the next day in the sedentary group rats after the first three doses of CHP. The exercise group rats showed no hypothermia after the first dose of CHP. However, they became hypothermic after the second and third doses of CHP. The exercise group rats developed a smaller daytime fever after each dose of CHP compared to the sedentary group rats. Overall, exercise training attenuated the hypothermic and febrile effects of repeated CHP. Thus, the data suggest that a sedentary lifestyle may increase the sensitivity to OP insecticides. Exercise training was also associated with a more rapid recovery of plasma cholinesterase activity. PMID:12706752

  13. Thermoregulatory effects of chlorpyrifos in the rat: long-term changes in cholinergic and noradrenergic sensitivity.

    PubMed

    Gordon, C J

    1994-01-01

    Subcutaneous injection of a sublethal dose of chlorpyrifos (CHLP), an organophosphate (OP) pesticide, causes long-term inhibition in cholinesterase activity (ChE) of brain, blood, and other tissues. Such prolonged inhibition in ChE should lead to marked behavioral and autonomic thermoregulatory patterns, especially in terms of altered noradrenergic and cholinergic sensitivity. To evaluate the behavioral and autonomic effects of long-term ChE inhibition, Long-Evans rats were implanted with radiotelemetry transmitters that continuously monitored core temperature (Tc), heart rate (HR), and motor activity (MA). These parameters were monitored for 7 days following a single injection of peanut oil (vehicle control) or 280 mg/kg CHLP. CHLP led to a significant reduction in Tc during the first night after treatment but had no other effects on Tc. CHLP also resulted in a significant elevation in HR which lasted for approximately 72 h. Motor activity was unaffected by CHLP. Cholinergic and noradrenergic drug sensitivity was assessed between 7 and 25 days after CHLP. CHLP-treated rats were more sensitive to norepinephrine as based on a greater hyperthermic response. MA of CHLP-treated rats was more sensitive to scopolamine. On the other hand, the hypothermic effects of oxotremorine (0.4 mg/kg) were nearly abolished by CHLP treatment, indicating tolerance to cholinergic stimulation. The tachycardic effects of methyscopolamine were also greater in the CHLP group. Overall, the acute effects of CHLP are unusual compared to other OP's in that there is no hypothermic response, an attenuated nocturnal elevation in Tc and a prolonged elevation in HR.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7514260

  14. Prolonged elevation in blood pressure in the unrestrained rat exposed to chlorpyrifos.

    PubMed

    Gordon, C J; Padnos, B K

    2000-04-20

    Organophosphate (OP) pesticides are likely to alter the regulation of blood pressure (BP) because (i) BP control centers in the brain stem utilize cholinergic synapses and (ii) the irreversible inhibition of acetylcholinesterase activity by OP's causes cholinergic stimulation in the CNS. This study used radiotelemetric techniques to monitor systolic (S), diastolic (D), mean (M) BP, pulse pressure (systolic-diastolic), heart rate (HR), core temperature (T(c)), and motor activity in male Long-Evans rats treated with the OP pesticide chlorpyrifos (CHP) at doses of 0, 5, 10, and 25 mg/kg (p.o.) at 15:00 h 10 and 25 mg/kg CHP led to parallel elevations in S-BP, M-BP, and D-BP within 2 h after dosing. BP increased 15-20 mmHg above controls and increases persisted throughout the night and into the next day. HR decreased slightly in rats administered 25 but not 10 mg/kg CHP. T(c) was reduced by treatment with 25 mg/kg CHP and then increased above controls the next day. Motor activity was reduced by treatment with 25 but not 10 mg/kg CHP. Pulse pressure was elevated by 2-4 mmHg for 40 h after exposure to 10 and 25 mg/kg CHP. The increase in BP without an increase in HR suggests that CHP increases total peripheral resistance and may alter the baroreflex control of BP. Cholinergic stimulation of the CNS may explain the initial effects of CHP on BP; however, the persistent elevation suggests an involvement of neurohumoral pressor pathways. PMID:10773358

  15. THE CANNABINOID RECEPTOR ANTAGONIST AM251 INCREASES PARAOXON AND CHLORPYRIFOS OXON TOXICITY IN RATS

    PubMed Central

    Liu, Jing; Pope, Carey

    2014-01-01

    Organophosphorus anticholinesterases (OPs) elicit acute toxicity by inhibiting acetylcholinesterase (AChE), leading to acetylcholine accumulation and overstimulation of cholinergic receptors. Endocannabinoids (eCBs, e.g., arachidonoyl ethanolamide [AEA] and 2-arachidonoyl glycerol [2-AG]) are neuromodulators that regulate neurotransmission by reducing neurotransmitter release. The eCBs are degraded by the enzymes fatty acid amide hydrolase (FAAH, primarily involved in hydrolysis of AEA) and monoacylglycerol lipase (MAGL, primarily responsible for metabolism of 2-AG). We previously reported that the cannabinoid receptor agonist WIN 55,212-2 reduced cholinergic toxicity after paraoxon exposure. This study compared the effects of the cannabinoid receptor antagonist AM251 on acute toxicity following either paraoxon (PO) or chlorpyrifos oxon (CPO). CPO was more potent in vitro than PO at inhibiting AChE (≈ 2 fold), FAAH (≈ 8 fold), and MAGL (≈ 19 fold). Rats were treated with vehicle, PO (0.3 and 0.6 mg/kg, sc.) or CPO (6 and 12 mg/kg, sc.) and subsets treated with AM251 (3 mg/kg, ip; 30 min after OP). Signs of toxicity were recorded for four hours and rats were then sacrificed. OP-treated rats showed dose-related involuntary movements, with AM251 increasing signs of toxicity with the lower dosages. PO and CPO elicited excessive secretions, but AM251 had no apparent effect with either OP. Lethality was increased by AM251 with the higher dosage of PO, but no lethality was noted with either dosage of CPO, with or without AM251. Both OPs caused extensive inhibition of hippocampal AChE and FAAH (>80–90%), but only CPO inhibited MAGL (37–50%). These results provide further evidence that eCB signaling can influence acute OP toxicity. The selective in vivo inhibition of MAGL by CPO may be important in the differential lethality noted between PO and CPO with AM251 co-administration. PMID:25447325

  16. Effect of Chlorpyrifos Ethyl on Acetylcholinesterase Activity in Climbing Perch (Anabas testudineus, Bloch, 1972).

    PubMed

    Tam, Nguyen Thanh; Berg, Håkan; Tuyen, Phan Thi Bich; Van Cong, Nguyen

    2015-11-01

    The high use of pesticides in intensive rice farming in the Mekong Delta constitutes a potential hazard to the environment and to people's health. Chlorpyrifos ethyl (CPF) is a commonly used organophosphate (OP) insecticide, but information about its potential negative impacts on the aquatic environment in the Mekong Delta is scarce. Both acute and subacute toxicity tests were performed in a static nonrenewable system to investigate the effects of CPF on brain acetylcholinesterase (AChE) activity in native climbing perch fingerlings (Anabas testudineus, Bloch, 1972). Environmental parameters, such as dissolved oxygen, water temperature, and pH, were similar to field conditions in the Mekong Delta. In a 96-h lethal concentration (LC50) test, fingerlings of climbing perch were randomly exposed to five levels of CPF ranging from 0.8 to 4.5 ppm. Five sublethal levels of CPF (1, 5, 10, 15, and 20 % of the 96-h LC50 value) were tested to assess the sensitivity and recovery of the brain AChE activity in climbing perch fingerlings exposed to CPF. The results showed that CPF were moderately toxic to climbing perch with a 96-h median LC50 of 1.73 ppm. CPF also caused long-term AChE inhibition with 70 % inhibition remaining after 96 h for the four highest test concentrations. The recovery of brain AChE activity in fish placed in CPF-free water was very slow, and after 7 days the brain AChE activity was still significant lower in fish from the four highest concentrations compared with the control. The results from this study indicate that OP insecticides, such as CPF, can have long-lasting sublethal effects on aquatic species in the Mekong Delta. PMID:26135300

  17. Critical Duration of Exposure for Developmental Chlorpyrifos-Induced Neurobehavioral Toxicity

    PubMed Central

    Sledge, Damiyon; Yen, Jerry; Morton, Terrell; Dishaw, Laura; Petro, Ann; Donerly, Susan; Linney, Elwood; Levin, Edward D.

    2011-01-01

    Developmental exposure of rats to the pesticide chlorpyrifos (CPF) causes persistent neurobehavioral impairment. In a parallel series of studies with zebrafish, we have also found persisting behavioral dysfunction after developmental CPF exposure. We have developed a battery of measures of zebrafish behavior, which are reliable and sensitive to toxicant-induced damage. This study determined the critical duration of developmental CPF exposure for causing persisting neurobehavioral effects. Tests of sensorimotor response (tap startle response and habituation), stress response (novel tank diving test) and learning (3-chamber tank spatial discrimination) were conducted with adult zebrafish after early developmental CPF exposure. The CPF exposure level was 100 ng/ml with durations of 0-1, 0-2, 0-3, 0-4 and 0-5 days after fertilization. Developmental CPF exposure had persisting behavioral effects in zebrafish tested as adults. In the tactile startle test, CPF exposed fish showed decreased habituation to startle and a trend toward increased overall startle response. In the novel tank exploration test, exposed fish showed decreased escape diving response and increased swimming activity. In the 3-chamber learning test, the 0-5 day CPF exposure group had a significantly lower learning rate. There was evidence for persisting declines in brain dopamine and norepinepherine levels after developmental CPF exposure. In all of the measures the clearest persistent effects were seen in fish exposed for the full duration of five days after fertilization. In a follow-up experiment there were some indications for persisting behavioral effects after exposure during only the later phase of this developmental window. This study demonstrated the selective long-term neurobehavioral alterations caused by exposure to CPF in zebrafish. The zebrafish model can facilitate the determination of the molecular mechanisms underlying long-term neurobehavioral impairment after developmental toxicant

  18. Co-treatment of chlorpyrifos and lead induce serum lipid disorders in rats: Alleviation by taurine.

    PubMed

    Akande, Motunrayo G; Aliu, Yusuf O; Ambali, Suleiman F; Ayo, Joseph O

    2016-07-01

    The aim of this study was to investigate the effects of taurine (TA) on serum lipid profiles following chronic coadministration of chlorpyrifos (CP) and lead acetate (Pb) in male Wistar rats. Fifty rats randomly distributed into five groups served as subjects. Distilled water (DW) was given to DW group, while soya oil (SO; 1 mL kg(-1)) was given to SO group. The TA group was treated with TA (50 mg kg(-1)). The CP + Pb group was administered sequentially with CP (4.25 mg kg(-1); 1/20th median lethal dose (LD50)) and Pb at 233.25 mg kg(-1) (1/20th LD50), while the TA + CP + Pb group received TA (50 mg kg(-1)), CP (4.25 mg kg(-1)), and Pb (233.25 mg kg(-1)) sequentially. The treatments were administered once daily by oral gavage for 16 weeks. The rats were euthanised, and the blood samples were collected at the termination of the study. Sera obtained from the blood samples were analyzed for total cholesterol, high-density lipoprotein cholesterol, triglycerides, and malondialdehyde, and also the activities of serum antioxidant enzymes including superoxide dismutase, catalase and glutathione peroxidase were analyzed. The low-density lipoprotein cholesterol, very-low-density lipoprotein cholesterol, and atherogenic index were calculated. The results showed that CP and Pb induced alterations in the serum lipid profiles and evoked oxidative stress. TA alleviated the disruptions in the serum lipid profiles of the rats partially by mitigating oxidative stress. It was concluded that TA may be used for prophylaxis against serum lipid disorders in animals that were constantly co-exposed to CP and Pb in the environment. PMID:25537622

  19. Longitudinal Assessment of Chlorpyrifos Exposure and Effect Biomarkers in Adolescent Egyptian Agricultural Workers

    PubMed Central

    Crane, Alice L.; Abdel Rasoul, Gaafar; Ismail, Ahmed A.; Hendy, Olfat; Bonner, Matthew R.; Lasarev, Michael R.; Al-Batanony, Manal; Singleton, Steven T.; Khan, Khalid; Olson, James R.; Rohlman, Diane S.

    2014-01-01

    Chlorpyrifos (CPF) is applied seasonally in Egypt by adolescent agricultural workers and the extent of occupational exposure and the potential for environmental CPF exposure in this population is poorly understood. Adolescent pesticide applicators (n=57; 12–21 years of age) and age matched non-applicators (n=38) from the same villages were followed for 10 months in 2010, spanning pre-application through post-application. Eight urine and 5 blood samples were collected from participants within this time period. Blood acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) (exposure/effect biomarker) and urine 3,5,6-trichloro-2-pyridinol (TCPy) (exposure biomarker) were used to assess occupational CPF exposures in pesticide applicators and environmental exposures in non-applicators. Applicators demonstrated significantly higher TCPy concentration and BChE depression than non-applicators throughout CPF application. This difference persisted for 4–7 weeks after the cessation of agricultural spraying. However, both groups exhibited significantly elevated TCPy and depressed BChE, compared to their respective baseline. The peak TCPy levels during the spray season (95% confidence interval) for non-applicators and applicators reached 16.8 (9.87–28.5) and 137 (57.4–329) ug/g creatinine, respectively. BChE levels (95% confidence intervals) during the spray were 1.47 (1.28–1.68) for non-applicators and 0.47 (0.24–0.94) U/ml for applicators. The longitudinal assessment of CPF biomarkers provided robust measures of exposure and effect throughout CPF application in adolescents and revealed significant exposures in both applicators and non-applicators. Biomarker data in the non-applicators, which mirrored that of the applicators, indicated that non-applicators received environmental CPF exposures. This suggests that similar exposures may occur in other residents of this region during periods of pesticide application. PMID:23321857

  20. Diploid and triploid African catfish (Clarias gariepinus) differ in biomarker responses to the pesticide chlorpyrifos.

    PubMed

    Karami, Ali; Goh, Yong-Meng; Jahromi, Mohammad Faseleh; Lazorchak, James M; Abdullah, Maha; Courtenay, Simon C

    2016-07-01

    The impacts of environmental stressors on polyploid organisms are largely unknown. This study investigated changes in morphometric, molecular, and biochemical parameters in full-sibling diploid and triploid African catfish (Clarias gariepinus) in response to chlorpyrifos (CPF) exposures. Juvenile fish were exposed to three concentrations of CPF (mean measured μg/L (SD): 9.71 (2.27), 15.7 (3.69), 31.21 (5.04)) under a static-renewal condition for 21days. Diploid control groups had higher hepatosomatic index (HSI), plasma testosterone (T), and brain GnRH and cyp19a2 expression levels than triploids. In CPF-exposed groups, changes in HSI, total weight and length were different between the diploid and triploid fish. In contrast, condition factor did not alter in any of the treatments, while visceral-somatic index (VSI) changed only in diploids. In diploid fish, exposure to CPF did not change brain 11β-hsd2, ftz-f1, foxl2, GnRH or cyp19a2 mRNA levels, while reduced tph2 transcript levels compared to the control group. In contrast, 11β-hsd2 and foxl2 expression levels were changed in triploids following CPF exposures. In diploids, plasma T levels showed a linear dose-response reduction across CPF treatments correlating with liver weight and plasma total cholesterol concentrations. In contrast, no changes in plasma cholesterol and T concentrations were observed in triploids. Plasma cortisol and 17-β estradiol (E2) showed no response to CPF exposure in either ploidy. Results of this first comparison of biomarker responses to pesticide exposure in diploid and polyploid animals showed substantial differences between diploid and triploid C. gariepinus. PMID:26994807

  1. Single cell dynamic phenotyping

    PubMed Central

    Patsch, Katherin; Chiu, Chi-Li; Engeln, Mark; Agus, David B.; Mallick, Parag; Mumenthaler, Shannon M.; Ruderman, Daniel

    2016-01-01

    Live cell imaging has improved our ability to measure phenotypic heterogeneity. However, bottlenecks in imaging and image processing often make it difficult to differentiate interesting biological behavior from technical artifact. Thus there is a need for new methods that improve data quality without sacrificing throughput. Here we present a 3-step workflow to improve dynamic phenotype measurements of heterogeneous cell populations. We provide guidelines for image acquisition, phenotype tracking, and data filtering to remove erroneous cell tracks using the novel Tracking Aberration Measure (TrAM). Our workflow is broadly applicable across imaging platforms and analysis software. By applying this workflow to cancer cell assays, we reduced aberrant cell track prevalence from 17% to 2%. The cost of this improvement was removing 15% of the well-tracked cells. This enabled detection of significant motility differences between cell lines. Similarly, we avoided detecting a false change in translocation kinetics by eliminating the true cause: varied proportions of unresponsive cells. Finally, by systematically seeking heterogeneous behaviors, we detected subpopulations that otherwise could have been missed, including early apoptotic events and pre-mitotic cells. We provide optimized protocols for specific applications and step-by-step guidelines for adapting them to a variety of biological systems. PMID:27708391

  2. Behavior of pyrimethanil, pyraclostrobin, boscalid, cypermethrin and chlorpyrifos residues on raspberry fruit and leaves of Laszka variety.

    PubMed

    Sadło, Stanisław; Szpyrka, Ewa; Stawarczyk, Michał; Piechowicz, Bartosz

    2014-01-01

    The purpose of the research conducted was to investigate and evaluate the behavior of pyrimethanil, pyraclostrobin, boscalid, cypermethrin and chlorpyrifos, the active ingredients of selected fungicides and insecticides, on ripe fruit and in fully developed leaves of raspberry of the Laszka variety. The field trial was carried out in the period of one month starting from the first fruit picking. The results obtained indicated that residue levels on the day of the first crop picking did not even approximate the corresponding EU-MRLs (http://ec.europa.eu/sanco_pesticides). Individual substances in raspberry fruits and leaves disappeared at a similar rate. As a result of chlorpyrifos application to the soil, its residue in fruits and leaves occurred for the whole period of fruit bearing, though in fruit they dropped successively. To produce raspberries with residues below or equal to 0.01 μg g(-1), the application of pesticides should be stopped at least 2-3 weeks before the first crop picking, and on condition that an appropriate preparation (active in low doses) is applied to the last treatments.

  3. Inhibition, recovery and oxime-induced reactivation of muscle esterases following chlorpyrifos exposure in the earthworm Lumbricus terrestris.

    PubMed

    Collange, B; Wheelock, C E; Rault, M; Mazzia, C; Capowiez, Y; Sanchez-Hernandez, J C

    2010-06-01

    Assessment of wildlife exposure to organophosphorus (OP) pesticides generally involves the measurement of cholinesterase (ChE) inhibition, and complementary biomarkers (or related endpoints) are rarely included. Herein, we investigated the time course inhibition and recovery of ChE and carboxylesterase (CE) activities in the earthworm Lumbricus terrestris exposed to chlorpyrifos, and the ability of oximes to reactivate the phosphorylated ChE activity. Results indicated that these esterase activities are a suitable multibiomarker scheme for monitoring OP exposure due to their high sensitivity to OP inhibition and slow recovery to full activity levels following pesticide exposure. Moreover, oximes reactivated the inhibited ChE activity of the earthworms exposed to 12 and 48 mg kg(-1) chlorpyrifos during the first week following pesticide exposure. This methodology is useful for providing evidence for OP-mediated ChE inhibition in individuals with a short history of OP exposure (< or = 1 week); resulting a valuable approach for assessing multiple OP exposure episodes in the field. PMID:20334963

  4. Oxidative stress related to chlorpyrifos exposure in rainbow trout: Acute and medium term effects on genetic biomarkers.

    PubMed

    Benedetto, A; Brizio, P; Squadrone, S; Scanzio, T; Righetti, M; Gasco, L; Prearo, M; Abete, M C

    2016-05-01

    Organophosphates (OPs) are derivatives of phosphoric acid widely used in agriculture as pesticides. Chlorpyrifos (CPF) is an OP that is extremely toxic to aquatic organisms. Rainbow trout (Oncorhynchus mykiss) is considered as a sentinel model species for ecotoxicology assessment in freshwater ecosystems. An exposure study was carried out on rainbow trout to investigate genetic responses to CPF-induced oxidative stress by Real-Time PCR, and to determine the accumulation dynamics of CPF and toxic metabolite chlorpyrifos-oxon (CPF-ox) in edible parts, by HPLC-MS/MS. Among the genes considered to be related to oxidative stress, a significant increase in HSP70 mRNA levels was observed in liver samples up to 14 days after CPF exposure (0.05 mg/L). CPF concentrations in muscle samples reach mean values of 285.25 ng/g within 96 hours of exposure, while CPF-ox concentrations were always under the limit of quantification (LOQ) of the applied method. Our findings lead us to consider HSP70 as a suitable genetic marker in rainbow trout for acute and medium-term monitoring of CPF exposure, complementary to analytical determinations.

  5. Efficacy of Ganoderma sp. JAS4 in bioremediation of chlorpyrifos and its hydrolyzing metabolite TCP from agricultural soil.

    PubMed

    Silambarasan, Sivagnanam; Abraham, Jayanthi

    2014-01-01

    A novel fungal strain JAS4 was isolated from agricultural soil and was found to be highly effective in degrading chlorpyrifos and its major degradation product 3,5,6-trichloro-2-pyridinol (TCP). The molecular characterization based on 18S rRNA sequence analysis, revealed strain JAS4 as Ganoderma sp. which could able to degrade chlorpyrifos and its metabolite in an aqueous medium with rate constant of 0.8460 day(-1), following first order rate kinetics, and the time in which the initial insecticide concentration was reduced by 50% (DT(50)) was 0.81 days. Studies on biodegradation in soil with nutrients showed that JAS4 strain exhibited efficient degradation of insecticide with a rate constant of 0.9 day(-1), and DT(50) was 0.73 day. In contrast, degradation of insecticide in soil without nutrients was characterized by a rate constant of 0.7576 day(-1) and the DT(50) was 0.91 day.

  6. Chlorpyrifos residue levels in avian food items following applications of a commercial EC formulation to alfalfa and citrus.

    PubMed

    Brewer, Larry W; McQuillen, Harry L; Mayes, Monte A; Stafford, Jennifer M; Tank, Susan L

    2003-11-01

    Two 10-day field residue studies were conducted to measure the amount of chlorpyrifos residue found in typical avian food following applications of a commercial 480 g liter(-1) EC (Lorsban 4E) at 1.1 kg AI ha(-1) (1 lb AI acre(-1)) to alfalfa and at 2.3 kg Al ha(-1) (2.0 lb AI acre(-1)) to citrus. Avian food items used in these studies included: crickets (Acheta domestica (L)), earthworms (Lumbricus terrestris L), darkling ground beetle larvae (Tenebrio molitor L), seed heads (Triticum sp), and naturally occurring flying and ground-dwelling insects. The studies incorporated a design involving three main study plots placed within larger treated areas of an alfalfa crop and a mature orange grove. The three main study plots represented three replications and each contained four sub-plots. One sub-plot, on each study plot, was sampled on day 0 (2-h post-application), day 1, day 5 and day 10 post-application. Chlorpyrifos residues were present in all avian food sampled following the application; however, residue levels were lower than estimated residue values typically used by the US EPA to establish expected environmental concentration (EEC) used in screening assessments of risk to terrestrial wildlife. PMID:14620043

  7. THE DISTRIBUTION OF CHLORPYRIFOS FOLLOWING A CRACK AND CREVICE TYPE APPLICATION IN THE U.S. EPA INDOOR AIR QUALITY RESEARCH HOUSE

    EPA Science Inventory

    The paper gives results of a study to determine the spatial and temporal distribution of chlorpyrifos following a professional crack-and-crevice application in the kitchen of the U.S. EPA's indoor air quality research house in North Carolina. Following the application, measuremen...

  8. EXPOSURE OF PRESCHOOL CHILDREN TO CHLORPYRIFOS AND ITS DEGRADATION PRODUCT 3,5,6-TRICHLORO-2-PYRIDINOL IN THEIR EVERYDAY ENVIRONMENTS

    EPA Science Inventory

    As part of the Children's Total Exposure to Persistent Pesticides and Other Persistent Organic Pollutants (CTEPP) study, we investigated the exposures of preschool children to chlorpyrifos and its degradation product 3,5,6-trichloro-2-pyridinol (TCP) in their everyday environment...

  9. Biodegradation of chlorpyrifos and its hydrolysis product 3,5,6-trichloro-2-pyridinol using a novel bacterium Ochrobactrum sp. JAS2: A proposal of its metabolic pathway.

    PubMed

    Abraham, Jayanthi; Silambarasan, Sivagnanam

    2016-01-01

    Biodegradation of chlorpyrifos and its major metabolite 3,5,6-trichloro-2-pyridinol (TCP) were studied with a novel bacterial strain JAS2 isolated from paddy rhizosphere soil. The molecular characterization based on 16S rRNA gene sequence homology confirmed its identity as Ochrobactrum sp. JAS2. The JAS2 strain degraded 300mgl(-1) of chlorpyrifos within 12h of incubation in the aqueous medium and it produced the TCP metabolite. However, after 72h of incubation TCP was also completely degraded by the JAS2 strain. A tentative degradation pathway of chlorpyrifos by Ochrobactrum sp. JAS2 has been proposed on basis of GC-MS analysis. The complete degradation of chlorpyrifos occurred within 24h in the soil spiked with and without addition of nutrients inoculated with Ochrobactrum sp. JAS2. TCP was obtained in both the studies which was degraded completely by 96h in the soil spiked with nutrients and whereas 120h in absence of nutrients in the soil. The mpd gene which is responsible for organophosphorus hydrolase production was identified. The isolates Ochrobactrum sp. JAS2 also exhibited a time dependent increase in the amount of tricalcium phosphate solubilization in Pikovskaya's medium. Further screening of the strain JAS2 for auxiliary plant growth promoting activities revealed its remarkable capability of producing the indole acetic acid (IAA), hydrogen cyanide (HCN) and ammonia.

  10. CHARACTERIZATION OF THE IN VITRO KINETIC INTERACTION OF CHLORPYRIFOS-OXON WITH RAT SALIVARY CHOLINESTERASE: A POTENTIAL BIOMONITORING MATRIX. (R828608)

    EPA Science Inventory

    The primary mechanism of action for organophosphorus (OP) insecticides such as chlorpyrifos (CPF) involves the inhibition of acetylcholinesterase (AChE) by their active oxon metabolites resulting in a wide range of neurotoxic effects. These oxons also inhibit other cholinester...

  11. COMPARISON OF FIELD MEASUREMENTS FROM A CHILDREN'S PESTICIDE STUDY AGAINST PREDICTIONS FROM A PHYSICALLY BASED PROBABILISTIC MODEL FOR ESTIMATING CHILDREN'S RESIDENTIAL EXPOSURE AND DOSE TO CHLORPYRIFOS

    EPA Science Inventory

    Semi-volatile pesticides, such as chlorpyrifos, can move about within a home environment after an application due to physical/chemical processes, resulting in concentration loadings in and on objects and surfaces. Children can be particularly susceptible to the effects of pest...

  12. THE DISTRIBUTION OF CHLORPYRIFOS FOLLOWING A CRACK AND CREVICE TYPE APPLICATION IN THE U.S. EPA INDOOR AIR QUALITY TEST HOUSE

    EPA Science Inventory

    A study was conducted in the U.S. EPA Indoor Air Quality Test House to determine the spatial and temporal distribution of chlorpyrifos following a professional crack and crevice application in the kitchen. Following the application, measurements were made in the kitchen, den a...

  13. Urinary Biomarker, Dermal, and Air Measurement Results for 2,4-D and Chlorpyrifos Farm Applicators in the Agricultural Health Study

    EPA Science Inventory

    A subset of private pesticide applicators in the Agricultural Health Study (AHS) epidemiological cohort was monitored around the time of their agricultural use of 2,4-D and chlorpyrifos to assess exposure levels and potential determinants of exposure. Measurements included pre- a...

  14. Variation in susceptibility of field strains of three stored grain insect species to spinosad and chlorpyrifos-methyl plus deltamethrin on hard red winter wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spinosad and chlorpyrifos-methyl plus deltamethrin efficacy at labeled rates on hard red winter wheat was evaluated against 11 strains of the red flour beetle, Tribolium castaneum (Herbst); six strains of the sawtoothed grain beetle, Oryzaephilus surinamensis (L.); and two strains of the lesser grai...

  15. Dual-template magnetic molecularly imprinted particles with multi-hollow structure for the detection of dicofol and chlorpyrifos-methyl.

    PubMed

    Yang, Tao; Feng, Shun; Lu, Yi; Yin, Chao; Wang, Jide

    2016-06-01

    In this work, a novel dual-template magnetic molecularly imprinted polymer particle for dicofol and chlorpyrifos-methyl was prepared through oil-in-water emulsifier-free emulsion technology. The resulting magnetic particles were characterized with electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. It was found that as-prepared particles were well-shaped spheres with multi-hollow structures and of a size around 125 μm. Meanwhile it showed a good magnetic sensitivity. The results testified that multi-hollow magnetic molecularly imprinted polymers possessed excellent recognition capacity and fast kinetic binding behavior to the objective molecules. The maximum binding amounts toward dicofol and chlorpyrifos-methyl were 31.46 and 25.23 mg/g, respectively. The feasibility of the use of the particles as a solid-phase extraction sorbent was evaluated. Satisfactory recoveries ranging from 90.62 to 111.47 and 91.07 to 94.03% were obtained for dicofol and chlorpyrifos-methyl, respectively, spiked at three concentration levels from real samples. The Langmuir isotherm equation provided an excellent fit to the equilibrium sorption data of either dicofol or chlorpyrifos-methyl. It provided a novel way to advise dual-template magnetic molecularly imprinted polymer particles to adsorb pesticides with high selectivity.

  16. THE DISTRIBUTION OF CHLORPYRIFOS FOLLOWING A CRACK AND CREVICE TYPE APPLICATION IN THE U.S. EPA INDOOR AIR QUALITY RESEARCH HOUSE

    EPA Science Inventory

    A study was conducted in the U.S. EPA Indoor Air Quality Research House to determine the spatial and temporal distribution of chlorpyrifos following a professional crack and crevice application in the kitchen. Following the application, measurements were made in the kitchen, de...

  17. Dual-template magnetic molecularly imprinted particles with multi-hollow structure for the detection of dicofol and chlorpyrifos-methyl.

    PubMed

    Yang, Tao; Feng, Shun; Lu, Yi; Yin, Chao; Wang, Jide

    2016-06-01

    In this work, a novel dual-template magnetic molecularly imprinted polymer particle for dicofol and chlorpyrifos-methyl was prepared through oil-in-water emulsifier-free emulsion technology. The resulting magnetic particles were characterized with electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. It was found that as-prepared particles were well-shaped spheres with multi-hollow structures and of a size around 125 μm. Meanwhile it showed a good magnetic sensitivity. The results testified that multi-hollow magnetic molecularly imprinted polymers possessed excellent recognition capacity and fast kinetic binding behavior to the objective molecules. The maximum binding amounts toward dicofol and chlorpyrifos-methyl were 31.46 and 25.23 mg/g, respectively. The feasibility of the use of the particles as a solid-phase extraction sorbent was evaluated. Satisfactory recoveries ranging from 90.62 to 111.47 and 91.07 to 94.03% were obtained for dicofol and chlorpyrifos-methyl, respectively, spiked at three concentration levels from real samples. The Langmuir isotherm equation provided an excellent fit to the equilibrium sorption data of either dicofol or chlorpyrifos-methyl. It provided a novel way to advise dual-template magnetic molecularly imprinted polymer particles to adsorb pesticides with high selectivity. PMID:27119595

  18. `Weak A' phenotypes

    PubMed Central

    Cartron, J. P.; Gerbal, A.; Hughes-Jones, N. C.; Salmon, C.

    1974-01-01

    Thirty-five weak A samples including fourteen A3, eight Ax, seven Aend, three Am and three Ae1 were studied in order to determine their A antigen site density, using an IgG anti-A labelled with 125I. The values obtained ranged between 30,000 A antigen sites for A3 individuals, and 700 sites for the Ae1 red cells. The hierarchy of values observed made it possible to establish a quantitative relationship between the red cell agglutinability of these phenotypes measured under standard conditions, and their antigen site density. PMID:4435836

  19. Effects of acute chlorpyrifos exposure on in vivo acetylcholine accumulation in rat striatum

    SciTech Connect

    Karanth, Subramanya; Liu, Jing; Mirajkar, Nikita; Pope, Carey . E-mail: carey.pope@okstate.edu

    2006-10-01

    This study examined the acute effects of chlorpyrifos (CPF) on cholinesterase inhibition and acetylcholine levels in the striatum of freely moving rats using in vivo microdialysis. Adult, male Sprague-Dawley rats were treated with vehicle (peanut oil, 2 ml/kg) or CPF (84, 156 or 279 mg/kg, sc) and functional signs of toxicity, body weight and motor activity recorded. Microdialysis was conducted at 1, 4 and 7 days after CPF exposure for measurement of acetylcholine levels in striatum. Rats were then sacrificed and the contralateral striatum and diaphragm were collected for biochemical measurements. Few overt signs of cholinergic toxicity were noted in any rats. Body weight gain was significantly affected in the high-dose (279 mg/kg) group only, while motor activity (nocturnal rearing) was significantly reduced in all CPF-treated groups at one day (84 mg/kg) or from 1-4 days (156 and 279 mg/kg) after dosing. Cholinesterase activities in both diaphragm and striatum were markedly inhibited (50-92%) in a time-dependent manner, but there were relatively minimal dose-related changes. In contrast, time- and dose-dependent changes in striatal acetylcholine levels were noted, with significantly higher levels noted in the high-dose group compared to other groups. Maximal increases in striatal acetylcholine levels were observed at 4-7 days after dosing (84 mg/kg, 7-9-fold; 156 mg/kg, 10-13-fold; 279 mg/kg, 35-57-fold). Substantially higher acetylcholine levels were noted when an exogenous cholinesterase inhibitor was included in the perfusion buffer, but CPF treatment-related differences were substantially lower in magnitude under those conditions. The results suggest that marked differences in acetylcholine accumulation can occur with dosages of CPF eliciting relatively similar degrees of cholinesterase inhibition. Furthermore, the minimal expression of classic signs of cholinergic toxicity in the presence of extensive brain acetylcholine accumulation suggests that some

  20. Diurnal variation in thermoregulatory response to chlorpyrifos and carbaryl in the rat.

    PubMed

    Gordon, C J; Mack, C M

    2001-12-14

    Time of day of exposure is rarely considered in the study of insecticide toxicology. It would be expected that the circadian temperature rhythm (CTR) as well as the circadian rhythms of other physiological processes would affect the efficacy of anticholinesterase (antiChE) insecticides. The ability of antiChE insecticides to alter core temperature (T(c)) could be affected by time of exposure in relation to the CTR. To this end, we assessed time of exposure on the efficacy of the antiChE insecticides chlorpyrifos (CHP) and carbaryl (CAR) to alter T(c) in the rat. T(c) and motor activity (MA) were monitored by radiotelemetry. Rats were dosed orally with 0, 30, and 50 mg/kg CHP or 0, 25 and 75 mg/kg CAR at 09:00 and 15:00 h. Both insecticides caused an acute decrease followed by a delayed increase in T(c) by 24-48 h post-exposure. The temperature index (TI) (area under curve of DeltaT(c) with time) was significantly greater when CHP was given at 15:00 h as compared with 09:00 h. The maximum decrease in T(c) was similar for morning and afternoon CHP. The TI following CAR was similar for morning and afternoon exposure. CHP suppressed the 24 h MA equally when given in the morning and afternoon. CAR was more effective in reducing MA when given in the morning as compared with the afternoon. The T(c) increase measured 24 h after dosing was greater when CHP was given in the morning. Overall, time of day affected the thermoregulatory toxicity of CHP but not CAR. Another experiment showed that the hypothermic efficacy of oxotremorine, a muscarinic agonist, was greater when injected at 09:00 h as compared with 15:00 h. Hence, cholinergic stimulation is probably not the only mechanism to explain the effects of the chronotoxicogical effects of some antiChE insecticides. PMID:11718951

  1. Repeated exposure to neurotoxic levels of chlorpyrifos alters hippocampal expression of neurotrophins and neuropeptides.

    PubMed

    Lee, Young S; Lewis, John A; Ippolito, Danielle L; Hussainzada, Naissan; Lein, Pamela J; Jackson, David A; Stallings, Jonathan D

    2016-01-18

    Chlorpyrifos (CPF), an organophosphorus pesticide (OP), is one of the most widely used pesticides in the world. Subchronic exposures to CPF that do not cause cholinergic crisis are associated with problems in cognitive function (i.e., learning and memory deficits), but the biological mechanism(s) underlying this association remain speculative. To identify potential mechanisms of subchronic CPF neurotoxicity, adult male Long Evans (LE) rats were administered CPF at 3 or 10mg/kg/d (s.c.) for 21 days. We quantified mRNA and non-coding RNA (ncRNA) expression profiles by RNA-seq, microarray analysis and small ncRNA sequencing technology in the CA1 region of the hippocampus. Hippocampal slice immunohistochemistry was used to determine CPF-induced changes in protein expression and localization patterns. Neither dose of CPF caused overt clinical signs of cholinergic toxicity, although after 21 days of exposure, cholinesterase activity was decreased to 58% or 13% of control levels in the hippocampus of rats in the 3 or 10mg/kg/d groups, respectively. Differential gene expression in the CA1 region of the hippocampus was observed only in the 10mg/kg/d dose group relative to controls. Of the 1382 differentially expressed genes identified by RNA-seq and microarray analysis, 67 were common to both approaches. Differential expression of six of these genes (Bdnf, Cort, Crhbp, Nptx2, Npy and Pnoc) was verified in an independent CPF exposure study; immunohistochemistry demonstrated that CRHBP and NPY were elevated in the CA1 region of the hippocampus at 10mg/kg/d CPF. Gene ontology enrichment analysis suggested association of these genes with receptor-mediated cell survival signaling pathways. miR132/212 was also elevated in the CA1 hippocampal region, which may play a role in the disruption of neurotrophin-mediated cognitive processes after CPF administration. These findings identify potential mediators of CPF-induced neurobehavioral deficits following subchronic exposure to CPF at

  2. Repeated exposure to neurotoxic levels of chlorpyrifos alters hippocampal expression of neurotrophins and neuropeptides.

    PubMed

    Lee, Young S; Lewis, John A; Ippolito, Danielle L; Hussainzada, Naissan; Lein, Pamela J; Jackson, David A; Stallings, Jonathan D

    2016-01-18

    Chlorpyrifos (CPF), an organophosphorus pesticide (OP), is one of the most widely used pesticides in the world. Subchronic exposures to CPF that do not cause cholinergic crisis are associated with problems in cognitive function (i.e., learning and memory deficits), but the biological mechanism(s) underlying this association remain speculative. To identify potential mechanisms of subchronic CPF neurotoxicity, adult male Long Evans (LE) rats were administered CPF at 3 or 10mg/kg/d (s.c.) for 21 days. We quantified mRNA and non-coding RNA (ncRNA) expression profiles by RNA-seq, microarray analysis and small ncRNA sequencing technology in the CA1 region of the hippocampus. Hippocampal slice immunohistochemistry was used to determine CPF-induced changes in protein expression and localization patterns. Neither dose of CPF caused overt clinical signs of cholinergic toxicity, although after 21 days of exposure, cholinesterase activity was decreased to 58% or 13% of control levels in the hippocampus of rats in the 3 or 10mg/kg/d groups, respectively. Differential gene expression in the CA1 region of the hippocampus was observed only in the 10mg/kg/d dose group relative to controls. Of the 1382 differentially expressed genes identified by RNA-seq and microarray analysis, 67 were common to both approaches. Differential expression of six of these genes (Bdnf, Cort, Crhbp, Nptx2, Npy and Pnoc) was verified in an independent CPF exposure study; immunohistochemistry demonstrated that CRHBP and NPY were elevated in the CA1 region of the hippocampus at 10mg/kg/d CPF. Gene ontology enrichment analysis suggested association of these genes with receptor-mediated cell survival signaling pathways. miR132/212 was also elevated in the CA1 hippocampal region, which may play a role in the disruption of neurotrophin-mediated cognitive processes after CPF administration. These findings identify potential mediators of CPF-induced neurobehavioral deficits following subchronic exposure to CPF at

  3. Esterases activity in the axolotl Ambystoma mexicanum exposed to chlorpyrifos and its implication to motor activity.

    PubMed

    Robles-Mendoza, Cecilia; Zúñiga-Lagunes, Sebastian R; Ponce de León-Hill, Claudia A; Hernández-Soto, Jesús; Vanegas-Pérez, Cecilia

    2011-10-01

    The axolotl Ambystoma mexicanum is a neotenic salamander considered a good biological model due to its ability to regenerate limbs, tail, brain and heart cells. Nevertheless, severe reduction of A. mexicanum wild populations in the lacustrine area of Xochimilco, the natural habitat of the axolotl, could be related to several environmental pressures as the presence of organophosphate pesticides (OPPs), intensively applied in agricultural activities in Xochimilco. Thus the aim of this study was to evaluate the effect of environmentally realistic chlorpyrifos (CPF) concentrations, a OPP commonly used in this zone, on esterases activity (acetylcholinesterase and carboxylesterase) and bioconcentration of CPF and to relate them with the motor activity of A. mexicanum juveniles. Axolotls were exposed 48 h to 0.05 and 0.1mg CPF/L, and the responses were evaluated at the end of the CPF exposure. Results suggest that CPF is bioconcentrated into axolotls and that the CPF internal concentrations are related with the observed inhibition activity of AChE (>50%) and CbE (≈ 50%). CPF concentration responsible of the inhibition of the 50% of AChE activity (IC50) was estimated in 0.04 mg CPF/L; however IC50 for CbE activity was not possible to calculate since inhibition levels were lower than 50%, results that suggest a higher resistance of CbE enzymatic activity to CPF. However, motor activity was a more sensitive endpoint to CPF poisoning since time that axolotls spent active and walking, frequency and speed of swimming, frequency of prey attack were reduced >90% of control groups. The motor activity alterations in the axolotl could be related with the registered esterases inhibition. Thus important alterations on axolotls were identified even at short time and low concentrations of CPF exposure. Also, it was possible to link biochemical responses as esterases activity with higher levels of biological organization as behavior. This study provides tools for the regulation of the

  4. Understanding the degradation pathway of the pesticide, chlorpyrifos by noble metal nanoparticles.

    PubMed

    Bootharaju, M S; Pradeep, T

    2012-02-01

    Application of nanoparticles (NPs) in environmental remediation such as water purification requires a detailed understanding of the mechanistic aspects of the interaction between the species involved. Here, an attempt was made to understand the chemistry of noble metal nanoparticle-pesticide interaction, as these nanosystems are being used extensively for water purification. Our model pesticide, chlorpyrifos (CP), belonging to the organophosphorothioate group, is shown to decompose to 3,5,6-trichloro-2-pyridinol (TCP) and diethyl thiophosphate at room temperature over Ag and Au NPs, in supported and unsupported forms. The degradation products were characterized by absorption spectroscopy and electrospray ionization mass spectrometry (ESI MS). These were further confirmed by ESI tandem mass spectrometry. The interaction of CP with NP surfaces was investigated using transmission electron microscopy, energy dispersive analysis of X-rays, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). XPS reveals no change in the oxidation state of silver after the degradation of CP. It is proposed that the degradation of CP proceeds through the formation of AgNP-S surface complex, which is confirmed by Raman spectroscopy. In this complex, the P-O bond cleaves to yield a stable aromatic species, TCP. The rate of degradation of CP increases with increase of temperature and pH. Complete degradation of 10 mL of 2 ppm CP solution is achieved in 3 h using 100 mg of supported Ag@citrate NPs on neutral alumina at room temperature at a loading of ∼0.5 wt %. The effect of alumina and monolayer protection of NPs on the degradation of CP is also investigated. The rate of degradation of CP by Ag NPs is greater than that of Au NPs. The results have implications to the application of noble metal NPs for drinking water purification, as pesticide contamination is prevalent in many parts of the world. Study shows that supported Ag and Au NPs may be employed in sustainable

  5. The Phenotype of Loneliness

    PubMed Central

    Cacioppo, John T.; Cacioppo, Stephanie

    2012-01-01

    Goossens’ (in press) review nicely maps the progression of scientific research from its early focus on loneliness as a dysphoric state that results from the discrepancy between a person's ideal and actual social relationships to its current emphasis on the centrality of loneliness to our very nature as a social species, and he argues that developmental science throughout Europe has a great deal to contribute to our understanding of this construct. He concludes that psychologists should care about research on loneliness for five reasons: (i) it is a well-defined phenotype, (ii) it shows both high stability and individual differences in rates of change across years, (iii) it has adaptive value and evolutionary significance, (iv) it has a genetic substrate that is moderated by social environments, and (v) it has self-maintaining features that can lead to adverse mental health outcomes. Goossen's (2012) review is rife with information and ideas. We focus here on two additional important reasons and on the phenotype of loneliness. PMID:23024688