Concentrations Of Diazinon Research Articles

AN EXAMPLE OF THE IDENTIFICATION OF DIAZINON AS A PRIMARY TOXICANT IN AN EFFLUENT

A toxicity identification evaluation (TIE) conducted on a municipal wastewater discharge from the southeast United States was part of a research project aimed at developing U.S. Environmental Protection Agency (EPA) TIE methods for acutely toxic effluents. The effluent consistently exhibited acute toxicity to Ceriodaphnia dubia but not to fathead minnows (Pimephales promelas). Toxicity characterization procedures revealed that the primary toxicant was a nonpolar organic. Toxicity was recovered through C18 solid-phase extraction and concentration steps. Gas chromatography–mass spectroscopy of these concentrates revealed the presence of diazinon (O, O-diethyl O-[6-methyl-2-(1-methylethyl)-4-pyrimidinyl] phosphorothioate). Diazinon concentrations in whole effluent, determined by GC analyses, correlated well with the toxicity measurements of each sample. Relative species sensitivity also implicated diazinon as the primary toxicant. This study illustrates the successful application of EPA TIE methodologies for identifying a nonpolar organic toxicant in a complex effluent. The significance of detecting diazinon at acutely toxic concentrations in municipal wastewater may indicate a more widespread problem in this region of the United States. This toxicity problem may be attributed to the chemical characteristics of diazinon and its applications.

The importance of biotransformation in the toxicity of xenobiotics to fish. I. Toxicity and bioaccumulation of diazinon in guppy ( Poecilia reticulata) and zebra fish ( Brachydanio rerio)

The 96-h LC 50 value of the organophosphorus pesticide diazinon ( O, O-Diethyl- O-2-isopropyl-4-methyl-6-pyrimidyl thiophosphate) was about 0.8 mg l for the guppy and about 8 mg l for the zebra fish. Both the guppy and the zebra fish metabolized diazinon. The detected metabolite was 2-isopropyl-6-methyl-4-pyrimidinol (pyrimidinol). Diazoxon ( O, O-diethyl- O-2-isopropyl-4-methyl-6-pyrimidylphos-phate) could not be found as a metabolite. After short exposures (up to 48 h) to low sublethal diazinon concentrations the body concentration of pyrimidinol was linearly dependent on the body concentration of diazinon. The ratio of pyrimidinol to diazinon body concentrations was about 5 times higher in the guppy than in the zebra fish. In both species however, the pyrimidinol level reached a maximum at concentrations corresponding to 1 4 to 1 2 of the LC 50 value and these levels were remarkably similar. Kinetic experiments at diazinon concentrations of 0.1 and 0.4 ppm pesticide in water showed that an apparent steady state was reached after 24 to 48 h. After longer exposures an increased accumulation of diazinon was observed concomitantly with the inhibition of pyrimidinol formation. The inhibition of the brain acetylcholinesterase reached 73% in the guppy and 83% in the zebra fish. The maximum of the inhibition was already reached when the concentration of diazinon in water was 25% of the LC 50 value. The factor of bioconcentration (BCF) was dependent on the level of the pesticide in the water and varied between 39 (in the guppy, at a water concentration of 0.1 ppm) and more than 300 (in the zebra fish, at a water concentration of 4 ppm). The results indicate that the metabolism plays a key role in the bioaccumulation and in the species specific toxicity of diazinon in fish.

Effect of diazinon on freeze-fracture images of microvilli of intestinal epithelial cells ofTilapia nilotica

The effect of the organophosphate insecticide, diazinon on the intramembranous particles (IMPs) of the microvilli of the intestinal epithelial cells of Tilapia nilotica fish was studied using freeze-fracture technique. Exposing fish to different repeated concentrations of diazinon (1/2LC50) caused a significant decrease in population density of IMPs in P- and E-faces. IMPs of microvilli found in intestinal epithelial cells are thought to represent many kinds of proteins including enzymes. In the present work, it is suggested that diazinon induced a reduction in enzymatic content of the membrane which was accompanied by a decrease in IMPs density of the microvilli.

Down-regulation of saxitoxin binding in house flies by pyrethroids and other insecticides

In vivo exposure of house flies to lethal concentrations of pyrethrum and cypermethrin greatly reduced binding of [ 3H]saxitoxin (STX) in nerve membrane preparations. The reduction in STX binding produced by cypermethrin was not concentration dependent, i.e., it did not increase as the concentration of cypermethrin was raised. Exposure of flies to lethal concentrations of diazinon or dieldrin also reduced STX binding, but to a lesser extent than with pyrethroids. Pyrethroids and other neuroexcitatory insecticides appear to cause an increased sodium ion influx, resulting in down-regulation of sodium channels. These results suggest that down-regulation of sodium channels is a consequence of intoxication by neuroexcitatory insecticides and that the reduction in STX binding is a consequence of a decrease in sodium channel density.

The efficacy of insecticides against the screw‐worm fly (Chrysomya bezziana)

A number of insecticides used for ectoparasite control in the livestock industry were screened for their efficacy against larvae of the screw-worm fly, Chrysomya bezziana, using in vivo and laboratory tests. Proprietary screw-worm fly treatments (after exposure to outdoor conditions for up to 10 days) were also tested against eggs and adults of C bezziana. Three of these were also evaluated on naturally acquired screw-worm infestations. Residual protection was generally of short duration. Among the organophosphorus compounds, the most effective formulations contained relatively high concentrations (3 to 4% al) of coumaphos, 2.5% fenchlorphos or low concentrations (0.05 to 0.5% al) of diazinon, chlorfenvinphos and fenthion methyl. Two chlorinated hydrocarbon insecticides containing 3% lindane and 5% dieldrin were very effective but are now prohibited for use in Australia. Preparations had serious deficiencies when used under field conditions, especially for treating large, deepseated myiases for which systemic insecticides are recommended. A comparison of methods demonstrated that a laboratory test could supersede live animal experimentation, at least for the initial screening of potential insecticides.

Concentrations of Diazinon, Chlorpyrifos, and Bendiocarb after Application in Offices

Airborne and surface concentrations of diazinon, chlorpyrifos (Dursban), and bendiocarb (Ficam) were measured at intervals up to 10 days after broadcast spray application onto the floors of seven offices. Results from this work can provide information to evaluate health hazards for workers and others entering treated buildings and can assist public agencies in setting guidelines or regulations. Diazinon and chlorpyrifos airborne concentrations peaked 4 hr after application at 163 and 27 micrograms/m3 of air sampled, respectively. The highest level of bendiocarb (2.7 micrograms/m3) was measured during treatment. Airborne concentrations measured for diazinon indicate that building occupants should not enter unventilated rooms for at least 2 days after spraying. Reentry into unventilated rooms 1 day after treatment with chlorpyrifos or bendiocarb would appear to be safe, however. Residues on aluminum plates and furniture were examined at intervals of up to 48 hr after spraying. In many cases, surface concentrations were higher at 24 or 48 hr than at 1 hr. Concentrations of residues removed from wood and painted metal furniture generally were higher than those on the aluminum plates. Peak residue concentrations were diazinon, 38 ng/cm2 of surface area sampled at 48 hr; chlorpyrifos, 5.9 ng/cm2 at 48 hr; and bendiocarb, 25 ng/cm2 at 1 and 24 hr. Workers who must enter buildings after insecticide application often are unaware of treatment plans and, therefore, are unable to take precautions to minimize their exposure. Inhalation and skin contact with insecticides can be reduced by providing office workers and building occupants with information on treatment times, health effects of insecticide overexposure, steps to take to reduce contact, and the perceived health risk. It is essential that treated areas be ventilated adequately before workers return to their offices.

Concentrations of Diazinon, Chlorpyrifos, and Bendiocarb after Application in Offices

Concentrations of Diazinon, Chlorpyrifos, and Bendiocarb after Application in Offices

Behavior of diazinon in a perch species

Accumulation, depletion and metabolism of 14C-labeled diazinon (100 mg/L) an organo phosphoric insecticide and acaricide was studied in a perch. Bioaccumulation factors of diazinon were found to be low. Depletion of diazinon and/or its metabolites in fresh water was fast. The substance was readily metabolized mainly by cleavage of the phosphoric acid moiety of the molecule. Highest concentrations of diazinon and/or its metabolites were found in the vertebral cord, lowest concentrations in the muscle. 14C-radiolabeled compound was synthesized in our institute. The synthesis is described.

Effects of Sublethal Exposure to Diazinon on Longevity and Temporal Division of Labor in the Honey Bee (Hymenoptera: Apidae)

When worker honey bees, Apis mellifera L., were exposed to sublethal pesticide concentrations, the majority of tests revealed no significant differences between control and treatment groups in the ages when tasks were conducted. Longevity was the most consistently affected category studied, with division-of-labor tasks not consistently affected. Single exposures to various concentrations of diazinon reduced longevity in one case and altered task performance in three cases—“clean,” “entrance,” and “forage.” In experiments that exposed workers once, twice, or three times to acetone or a dose of diazinon causing approximately 10% mortality, a number of adverse effects were seen; the majority were in the single-exposure groups. Longevity was reduced in two cases, and certain temporal division- of-labor tasks were adversely affected, especially nectar handling and foraging. Treatment age had a significant effect on the results, with workers treated at emergence being more sensitive to pesticide exposure than older workers (14 of the 20 significant results reported). Stress in the form of pesticide exposure and handling appears to be more harmful to newly emerged bees than any other age group. Longevity and foraging measures hold promise as potential methods of evaluating sublethal pesticide stress on the honey bee worker.

Disposal of concentrated solutions of diazinon using organic absorption and chemical and microbial degradation

AbstractPeat moss has been found to be an effective ‘organic matrix’ for the absorption and degradation of diazinon in experimental disposal pits. High concentrations of diazinon sorbed onto nutrient‐enriched commercial grade peat moss were rapidly degraded. Pits treated with diazinon concentrations ranging from 4000 to 32000 mg kg−1 contained less than 1 to 7 mg kg−1 after 18 weeks. Initially, degradation probably was due to hydrolysis resulting from the effects of heat, moisture, low pH and some microbial activity. Further degradation of the hydrolysis product, IMHP, was most likely due to microbial activity. The results obtained suggest that a managed degradation pit, containing a nutrient‐enriched organic matrix (peat moss), might provide a useful means for absorbing and neutralizing waste pesticide formulations because the materials used in this system are readily available and the system may be regenerative so that it can be used repeatedly.

Diazinon toxicity: Effect on protein and nucleic acid metabolism in the liver of zebrafish, Brachydanio rerio (Cyprinidae)

Four-month old adult siblings of zebrafish were exposed to four concentrations of diazinon for up to 168 h. DNA, RNA, protein and total free amino acid content were monitored in the liver. The DNA, RNA and protein contents were significantly reduced, whereas the amino acid content was significantly enhanced. All these changes showed dose- as well as time-dependent response.

Resistance levels ofTyphlodromus occidentalis (Acari: Phytoseiidae) from Washington apple orchards to ten pesticides

Nine Washington populations ofTyphlodromus (=Metaseiulus) occidentalis Nesbitt collected from commercial apple orchards were surveyed for resistance to ten pesticides. A susceptible population collected from wild blackberry which had no history of pesticide exposure was used in estimating resistance development. All populations from apple orchards were tolerant to high concentrations of azinphosmethyl, diazinon, endosulfan and propargite. Resistance was also apparent to these materials, especially for azinphosmethyl which produced over 100-fold resistance levels for several populations. Moderate to low levels of tolerance and resistance development were seen to field concentrations of cyhexatin, formetanate and carbaryl. Fenvalerate, methomyl and methidathion were all very toxic at field concentrations and little evidence of resistance development was apparent. The use of fenvalerate, methomyl or methidathion at a time whenT. occidentalis is active would likely abrogate favorable biological control of pestiferous orchard mites.

Frequency-dependent selection at the diazinon resistance locus of the Australian sheep blowfly, Lucilia cuprina

The egg to adult viability of susceptibles (SS) at the diazinon resistance locus of L. cuprina was facilitated by RS in mixed (1:1) cultures at diazinon concentrations greater than 0·0002 per cent (W/V) in the concentration range 0–0·00053 per cent (W/V). SS survived in mixed culture at concentrations lethal to pure cultures of this genotype. The egg to adult viability of RS was not influenced by the presence of SS.Trials at 0 per cent and 0·0002 per cent (W/V) diazinon showed the viability of both genotypes decreased in the presence of diazinon and with increasing density. Viability of RS was independent of its frequency in mixed culture but SS viability was enhanced at frequencies ≦20 per cent at the 0·0002 per cent (W/V) concentration. There was no indication of density × frequency interaction.

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

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.

Diazinon concentrations and blood cholinesterase activities in rats exposed to diazinon

The tissue distribution of diazinon and the inhibition of blood cholinesterase (ChE) activity were investigated in male rats which received a single intraperitoneal (i.p.) dose of diazinon (100 mg/kg body wt) in olive oil. Diazinon concentration in the blood reached a maximum 1–2 h after dosing. Comparing the distribution of diazinon among liver, kidney and brain in treated rats, the diazinon residue was much greater in the kidney than in other organs, being 500 times that in the liver and 11 times that in the brain at 8 h after dosing. Erythrocyte and plasma ChE activities were inhibited rapidly, but ChE inhibition was greater in the erythrocytes than in plasma.

Effects of diazinon on macroinvertebrates and insect emergence in outdoor experimental channels

Effects of diazinon on macroinvertebrates were assessed in three outdoor experimental channels from mid-May to mid-September, 1980. One channel served as a control and two channels as low and high treatments. Three dosing regimes were employed. The low and high treatment channels were continuously dosed for 12 wk to nominal concentrations of 0.3 and 3 μg/l, then increased to 6 and 12 μg/l for 4 wk, then the high treatment was increased to 30 μg/l with the low treatment channel returned to ambient. Diazinon concentrations did not reach the intended levels during the latter two dosing regimes. No consistent interchannel differences were observed in total macroinvertebrate abundance or in species diversity induces. Effects were noted at the lowest concentration for amphipods and insects. As diazinon concentrations were increased interchannel community structure changes became more pronounced. Elevated drift, especially amphipods and snails, occurred in the treated channels 4 wk after dosing began and following the increases in concentrations. Total numbers and species of insects emerging from the three channels were not greatly different but lower numbers of mayflies and damselflies emerged from the treated channels. Tolerance of macroinvertebrates to diazinon were as follows: flatworms, physid snails, isopods and chironomids most tolerant; leeches and the amphipod Crangonyx less tolerant; the amphipod Hyalella, mayflies, caddisflies and damselflies sensitive.

散布された有機リン粉剤の稲体における消長とコブノメイガ幼虫に対する殺虫力

Changes in insecticide concentrations in rice plant were analyzed after diazinon (3%), isoxathion (2%) and acephate . MTMC (1%.2%) dusts had been applied to rice plant by the bell-jar dusting method. Toxicity of these insecticides to rice leafroller larvae was tested by applying the leaf dipping method. The initial concentrations of diazinon, isoxathion and acephate in the leaf blades were 14.5, 43.4 and 12.8 ppm after dusting. Diazinon showed the fastest decrease whereas acephate showed the slowest decrease after 3 days. Thereafter the three insecticides showed the same pattern of decrease. LC 50 values for the 1st, 3rd and 5th instar larvae were 0. 79, 6. 0 and 11 ppm for diazinon, 0. 51, 2. 2 and 3. 5 ppm for isoxathion and 1. 9, 3. 0 and 14 ppm for acephate, rerpectively. The period during which the concentration of insecticides exceeded the LC 50 levels for the 1st, 3rd and 5th instar larvae in the leaf blades lasted 1. 6, 0. 3 and 0. 1 days for diazinon, 14, 5. 2 and 4. 4 days for isoxathion and 7. 0, 3. 3 and 0 days for acephate after dusting, respectively.

Concentration and movement of diazinon in air.

Airborne concentrations of diazinon were measured in rooms for 21 days after crack and crevice application. Residue levels were largest in treated rooms (38 micrograms/m3) after application, followed by adjacent (1 microgram/m3) and upper and lower rooms (ca. 0.4 microgram/m3). Low levels of diazinon were detected in all rooms 21 days after application. Small amounts of diazinon (corrected to an 8 min application period) were detected on respirator pads (2.6 microgram) and waist pads (2.3 microgram) worn by the applicator.

Diazinon-induced histopathological and hematological alterations in a freshwater teleost, Ophiocephalus punctatus

The histopathological changes in liver, stomach, intestine, kidney, and gills and the hematological changes produced by two sublethal concentrations of diazinon (0.2 and 0.4 mg/liter) in a freshwater teleost fish, Ophiocephalus punctatus, have been studied after 15 and 30 days of exposure. The most conspicuous pathological changes in the liver after 15 days were liver cord disarray, rupture of cell membrane, vacuolation in the cytoplasm of hepatocytes, and enlargement of nuclei. The liver damage became more severe in fish exposed for 30 days and was characterized by fibrosis, small degenerated nuclei, and invasion of a number of phagocytes into the necrosed tissue. The only visible change in the stomach was erosion of mucosa. In the intestine, a few villi were necrosed and nuclei were reduced in volume. In the kidney, shrinkage of the glomerular network and necrosis of proximal tubules were the most conspicuous changes. The distal and collecting tubules were ruptured and the nuclei were degenerated and pycnotic. Degeneration and thinning of epithelial lining of the lamellae, separation of the vascular layer from the epithelium, and in some cases fusion of the epithelium of adjacent villi were the alterations in the gill. In blood, hemoglobin, hematocrit, glucose, cholesterol, urea, sodium, and calcium levels increased while plasma proteins, chlorides, and inorganic phosphate remained unaltered. Among the serum enzymes, the activities of glutamic-oxalacetic transaminase, glutamic-pyruvic transaminase, alkaline phosphatase, and amylase increased while acid phosphatase and cholinesterase activities decreased on exposure to diazinon.

A fatal diazinon poisoning

A case of fatal suicidal ingestion of diazinon insecticide is presented. Diazinon concentrations in post-mortem body fluids and tissues were determined using electron capture and flame ionization gas-liquid chromatography. The highest concentrations of diazinon were found in blood, stomach contents, bile and adipose tissue.