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The present study enumerates the attenuating effects of curcumin and α-tocopherol against propoxur induced oxidative DNA damage in human peripheral blood mononuclear cells (PBMC). Cultured cells were isolated from peripheral blood of healthy volunteers, and were exposed to varying concentrations of propoxur (0–21 μg/ml) for 6, 12, and 24 h, and in combination with curcumin (9.2 μg/ml) or α-tocopherol (4.3 μg/ml) or both. Cytotoxic effect of propoxur was examined by MTT assay. The role of oxidative stress beneath the cytotoxicity of propoxur was evaluated by the measurement of reduced glutathione (GSH), malondialdehyde (MDA) and 8-hydroxy-2′-deoxyguanosine (8-OH-dG) levels in cell lysate. A concentration-dependent cell death, depletion of GSH, an increase in the level of both MDA and 8-OH-dG were observed. Co-treatment with curcumin or α-tocopherol significantly attenuates depleted GSH, decrease in MDA and 8-OH-dG levels in propoxur exposed cells (p < 0.05). The results of the present study provide experimental evidence of involvement of oxidative stress in propoxur-mediated genotoxicity in human PBMC and highlight the antioxidant role of curcumin and α-tocopherol following propoxur exposure. [ABSTRACT FROM PUBLISHER]

Water quality assessment was conducted on the Ruiru River, a tributary of an important tropical river system in Kenya, to determine baseline river conditions for studies on the aquatic fate of N-methyl carbamate (NMC) pesticides. Measurements were taken at the end of the long rainy season in early June 2013. Concentrations of copper (0.21-1.51 ppm), nitrates (2.28-4.89 ppm) and phosphates (0.01-0.50 ppm) were detected at higher values than in uncontaminated waters, and attributed to surface runoff from agricultural activity in the surrounding area. Concentrations of dissolved oxygen (8-10 ppm), ammonia (0.02-0.22 ppm) and phenols (0.19-0.83 ppm) were found to lie within normal ranges. The Ruiru River was found to be slightly basic (pH 7.08-7.70) with a temperature of 17.8-21.2°C. The half-life values for hydrolysis of three NMC pesticides (carbofuran, carbaryl and propoxur) used in the area were measured under laboratory conditions, revealing that rates of decay were influenced by the electronic nature of the NMCs. The hydrolysis half-lives at pH 9 and 18°C decreased in the order carbofuran (57.8 h) > propoxur (38.5 h) > carbaryl (19.3 h). In general, a decrease in the electron density of the NMC aromatic ring increases the acidity of the N-bound proton removed in the rate-limiting step of the hydrolysis mechanism. Our results are consistent with this prediction, and the most electron-poor NMC (carbaryl) hydrolyzed fastest, while the most electron-rich NMC (carbofuran) hydrolyzed slowest. Results from this study should provide baseline data for future studies on NMC pesticide chemical fate in the Ruiru River and similar tropical water systems. [ABSTRACT FROM AUTHOR]

The fate of the active ingredients of insecticide sprays after use in indoor environments was investigated. Indoor air sampling was performed through two types of adsorbents, namely, TENAX TA and XAD-2 (10 L). After sampling, both adsorbents were ultrasonically extracted and analyzed by Gas Chromatography coupled to Mass Spectroscopy. The separation and analysis of the selected compounds were satisfactory and fast (duration of the chromatographic run: 40 min). The method was linear for all examined chemicals over the tested range (2 to 50 ng of absolute compound); limits of detection ranged from 0.42 to 1.32 ng of absolute compound. The method was then applied in the determination of the active ingredients of three commercially available insecticide sprays that were separately used in a full-scale environmental chamber (30 m3). After spraying, the fate of the active ingredients [propoxur, piperonyl butoxide (PBO) and pyrethrin insecticides] was monitored over 40 minutes, with and without ventilation. Both adsorbent materials were proven to be efficient and the differences in the concentrations deriving from sampling with both materials were in almost all cases less than 10%. All chemicals were removed in rates that exceeded 80%, after the 40 minutes of monitoring, exhibiting different decay rates. The removal of insecticides was not significantly affected by the ventilation of the chamber. The correlation analysis of propoxur, PBO and pyrethrins with the aerosols of various sizes (15 fractions, from 0.3 to > 20 μ m) showed that propoxur and PBO mainly associated with the medium size aerosols (3-7.5 μm) while pyrethrins seem to link more with heavier particles (> 10 μm). [ABSTRACT FROM AUTHOR]

Studies were carried out to determine the toxicity of some selected pesticides on fresh water fish in a tropical environment. The uptake of the pesticides lindane, pentachlorophenol (PCP), and propoxur, which are frequently used by farmers and industrialists were studied in concrete ponds at the University of Cape Coast, in Ghana. The fishes used for the study were Oreochromis niloticus, Clarias gariepinus, and Chrysicthys nigrodigitatus, and were obtained from cultured ponds in the Cape Coast District and Mankessim in the Central Region and Weija Dam, in the Greater Accra region of Ghana. Single high lethal concentration (SD) or acute treatment and cumulative/chronic (or multiple minor) lethal concentration (CD) treatment were employed in administering the pesticides to the fishes via water. Gas chromatograph (GC) Electron Capture Detector (ECD) analysis was done on the dead fishes to see the extent of ingestion. The LC50 values obtained for lindane on the three fish samples were as follows: Chrysicthys - 0.38 mg L-1; Oreochromis - 0.42 mg L-1, and Clarias - 1.2 mg L-1. Mortalities occurred in fish within 3-5 days of application. For the PCP on Chrysicthys, Oreochromis, and Clarias species the LC50 values were 0.42, 0.32 and 0.64 mg L-1, respectively for over a 2-3 day period. For a three-time influx period of propoxur the LC50 for Chrysicthys, Oreochromis, and Clarias, were 22.0, 30.40, and 45.04 (all in mg L-1), respectively. The results obtained indicated that the pesticides had adverse effects on the general growth and reproduction of fishes. Gonadosomatic indices also showed that the pesticides affected the development of the body, the gonads, and their reproduction. [ABSTRACT FROM AUTHOR]

A synchronous fluorescence method for the determination of carbaryl (CAB), propoxur (PRO), and carbofuran (CAF) with the aid of multivariate calibration methods, such as classical least squares (CLS), principal component regression (PCR), and partial least squares (PLS), was proposed. Because the synchronous fluorescence spectra (SFS) of these three compounds are seriously overlapped, it is difficult to determine these compounds individually from their mixtures. In this work, the experimental conditions were investigated and optimized to obtain the high sensitivities and well‐defined waves for each analyte. Furthermore, chemometrics models were established from a set of known samples and were then applied to the prediction of these three pesticides in a set of validation samples with a relative prediction error (RPE T ) of around 4% and limits of detection of 0.50, 5.5, and 23 ng L -1 for carbaryl, propoxur, and carbofuran, respectively. The proposed method was also successfully applied to determine the contents of these three compounds in spiked fruit and vegetable samples. [ABSTRACT FROM AUTHOR]

Since a high percentage of cockroach infestation has been determined in hospitals in Kaohsiung, South Taiwan, insecticide resistances may have developed in the cockroach populations. To determine the resistances in cohorts of German cockroach ( Blattella germanica ) from hospitals and households to organophosphates, carbamates and pyrethroids, cockroaches were trapped from 30 hospitals and 30 households in this area. Bioassays by topical application were then carried out on the first generation bred in the laboratory. Resistance ratio (RR) was determined by comparing the LD 50 of the collected cohorts with that of a susceptible cohort. RR ranges of chlorpyrifos, propoxur and cypermethrin in the hospitals were 2.04 - 28.80, 2.86 - 30.86 and 1.95 - 14.05 and those in the household were 1.92 - 17.72, 6.93 - 62.50 and 2.80 - 27.35 respectively. Significant correlations among the RRs of the three insecticides were separately found in the hospitals and households, indicating the existence of cross resistance among the three groups of insecticides. The patterns of propoxur > chlorpyrifos > cypermethrin in hospitals and propoxur > cypermethrin > chlorpyrifos in households reflect that chlorpyrifos is more frequently used in hospitals than in households. In contrast, cypermethrin is used more frequently in households. [ABSTRACT FROM AUTHOR]

A simple spectrophotometric technique is reported for the determination of propoxur using the coupling complexing agents namely 2-amino, 4- ditrophenol and 2,4-dimethoxy aniline. The λmax observed for these coloured complexes were at 402 and 460nm respectively. The recoveries of propoxur pesticides obtained using the above procedure were reported in their formulations, water and food grains. [ABSTRACT FROM AUTHOR]

A flow injection spectrophotometric method for the determination of propoxur with diazotized 4-aminobenzoic acid as the coupling agent was developed. The determination involves on-line hydrolysis at room temperature of the propoxur with sodium hydroxide. The resulting 2-isopropoxyphenol is coupled with diazotized 4-aminobenzoic acid in order to achieve an appropriate selectivity and sensitivity to the spectrophotometric measurements. The calibration curve is linear over the range 1-10 mg L[sup -1] of propoxur. The proposed method has provided a detection limit of 0.15 mg L[sup -1] of propoxur and a sample frequency of 120 injections per hour. The relative standard deviation of six independent determinations of a sample containing 5 mg L[sup -1] propoxur was 0.74%. The suitability of the proposed procedure for the determination of propoxur in commercial pesticide formulations was studied. The procedure provides results comparable to those obtained by the liquid chromatography analysis. [ABSTRACT FROM AUTHOR]

Wine and Arak, the national alcoholic drink in Lebanon, were prepared from grape juice fortified with fenitrothion to a concentration of 20ppm. Samples of the 11 fractions produced by the fermentation and distillation steps were analyzed for fenitrothion residues using gas chromatography (GC) and enzyme-linked immunosorbent assay (ELISA). Results of residue analyses showed that the two techniques were highly correlated (r = 0.978) and indicated that fenitrothion was stable during the fermentation steps but not during distillation. The clarified wine 35 days later contained about 85% (15.3 ppm) of the fenitrothionconcentration found in the juice as determined by GC analysis. Arak was prepared by a two-steps distillation of the clarified wine. The alcohol distillate and undistilled fraction from the first distillation contained 2.5 ppm and 5.8 ppm of fenitrothion, respectively. No fenitrothion residues were detected by both techniques in the four fractions collected from the second distillation step. [ABSTRACT FROM AUTHOR]