Honey as a bioindicator of environmental organochlorine insecticides contamination

Honey is a suitable matrix for the evaluation of environmental contaminants including organochlorine insecticides. The present study was conducted to evaluate residues of fifteen organochlorine insecticides in honey samples of unifloral and multifloral origins from Dir, Pakistan. Honey samples (5 g each) were extracted with GC grade organic solvents and then subjected to Rotary Evaporator till dryness. The extracts were then mixed with n-Hexane (5 ml) and purified through Column Chromatography. Purified extracts (1μl each) were processed through Gas Chromatograph coupled with Electron Capture Detector (GC-ECD) for identification and quantification of the insecticides. Of the 15 insecticides tested, 46.7% were detected while 53.3% were not detected in the honey samples. Heptachlor was the most prevalent insecticide with a mean level of 0.0018 mg/kg detected in 80% of the samples followed by β-HCH with a mean level of 0.0016 mg/kg detected in 71.4% of the honey samples. Honey samples from Acacia modesta Wall. were 100% positive for Heptachlor with a mean level of 0.0048 mg/kg followed by β-HCH with a mean level of 0.003 mg/kg and frequency of 83.3%. Minimum levels of the tested insecticides were detected in the unifloral honey from Ziziphus jujuba Mill. Methoxychlor, Endosulfan, Endrin and metabolites of DDT were not detected in the studied honey samples. Some of the tested insecticides are banned in Pakistan but are still detected in honey samples indicating their use in the study area. The detected levels of all insecticides were below the Maximum Residue Levels (MRLs) and safe for consumers. However, the levels detected can cause mortality in insect fauna. The use of banned insecticides is one of the main factors responsible for the declining populations of important insect pollinators including honeybees.

Evaluation of pesticide residues in commercial Swiss beeswax collected in 2019 using ultra-high performance liquid chromatographic analysis

The aim of this study was to determine residue levels of pesticides in Swiss commercial beeswax. Foundation samples were collected in 2019 from nine commercial manufacturers for analysis of 21 pesticides using ultra-high performance liquid chromatography. Individual samples showed the variability and residue ranges and pooled samples represented the average annual residue values of the Swiss production. In total, 17 pesticides were identified and 13 pesticides were quantified. They included 13 acaricides and/or insecticides, two fungicides as well as a synergist and a repellent. The means calculated from individual samples were similar to the average annual residue values for most tested pesticides. Mean values of 401, 236, 106 and 3 μg·kg−1 were obtained for the beekeeping-associated contaminants coumaphos, tau-fluvalinate, bromopropylate and N-(2,4-Dimethylphenyl)-formamide (DMF; breakdown product of amitraz), respectively. For the other pesticides, the mean values were 203 μg·kg−1 (synergist piperonyl butoxide), 120 μg·kg−1 (repellent N,N-Diethyl-3-methylbenzamide, DEET), 19 μg·kg−1 (chlorfenvinphos) and 4 μg·kg−1 ((E)-fenpyroximate), while the means for acrinathrin, azoxystrobin, bendiocarb, boscalid, chlorpyrifos, flumethrin, permethrin, propoxur and thiacloprid were below the limit of quantification (< LOQ). Individual samples contained from seven to 14 pesticides. The ranges of values for coumaphos and piperonyl butoxide (from 14 to 4270 μg·kg−1; from 6 to 1555 μg·kg−1, respectively) were larger as compared to the ranges of values for DEET and tau-fluvalinate (from < LOQ to 585 μg·kg−1; from 16 to 572 μg·kg−1, respectively). In conclusion, the most prominent contaminants were the pesticides coumaphos and tau-fluvalinate, which are both acaricides with previous authorization for beekeeping in Switzerland, followed by piperonyl butoxide, a synergist to enhance the effect of insecticides. Graphical abstract

The Effects of Formulation on Imidacloprid Dissipation in Grapes and Vine Leaves and on Required Pre-Harvest Intervals under Lebanese Climatic Conditions

In this study, imidacloprid, a systemic insecticide, currently having a specified European Commission MRL value for vine leaves (2 mg kg−1), was applied on a Lebanese vineyard under different commercial formulations: as a soluble liquid (SL) and water dispersible granules (WDG). In Lebanon, many commercial formulations of imidacloprid are subject to the same critical good agricultural practice (cGAP). It was, therefore, important to verify the variability in dissipation patterns according to matrix nature and formulation type. Random samplings of grapes and vine leaves were performed starting at 2 days until 18 days after treatment. Residue extractions were performed according to the QuEChERS method and the analytical determination using liquid chromatography coupled to tandem mass spectrometry (LC-MS-MS). The SL formulation yielded significantly higher initial deposit than the WDG formulation on grapes and vine leaves. The formulation type did not significantly affect the dissipation rates; the estimated half-lives in grapes and vine leaves were 0.5 days for all imidacloprid formulations. No pre-harvest intervals were necessary on grapes. PHIs of 3.7 days for the SL formulation and 2.8 days for the WDG formulation were estimated on vine leaves. The results showed that the type of formulation and the morphological and physiological characteristics of the matrix had an effect on the initial deposits, and thus residue levels, but not on the dissipation patterns.

Investigation of Beta-Lactam and Tetracycline Group Antibiotic Residues in Bovine Liver, Kidney and Muscle Tissue

In this study, beta-lactam and tetracycline antibiotic residues were investigated in cattle liver, kidney and muscle samples. For this purpose, a total of 75 bovine tissue samples (each of 25 from liver, kidney, muscle) taken from 25 cattle slaughtered in a local slaughterhouse in Sivas were used as materials. ELISA method was applied in the analysis and it was studied with commercial test kits. According to the results of the analysis; beta-lactam and tetracycline residues were detected in all bovine tissue samples. Beta-lactam level was determined between 0.75-1.07 ppb (mean 0.94 ± 0.01) in liver samples, 0.67-1.05 ppb (mean 0.81 ± 0.01) in kidney samples and 0.70-2.57 ppb (mean 0.97 ± 0.07) in muscle samples. Tetracycline level was detected in the range of 4.48-8.50 ppb (mean 6.14 ± 0.17) in liver samples, 1.73-6.39 ppb (mean 4.90 ± 0.24) in kidney samples and 3.31-7.45 ppb (mean 5.67 ± 0.25) in muscle samples. The residue levels determined in the examples complied with the legal limits reported in the European Commission and the Turkish Food Codex Communiqué.

Pesticide residues analysis in farm gate vegetables of agricultural areas in Tumakuru district, Karnataka, India

The main purpose of this experiment was to understand pesticide residues persistence and their toxicity level in vegetables. In the present study pesticide residues in tomato (Solanum lycopersicum) and capsicum (Capsium annuum L.) vegetables cultivated in Tumakuru, Gubbi, Kunigal and Pavagada taluks in Tumkur district were analysed. In methodology, samples of 1 kg each were collected, cut into small pieces, macerated in a grinder and used for the analysis. Pesticides were quantified by gas chromatography-mass spectrometry (GC-MS). Results showed tomato samples of Pavagada recorded acephate (0.346 mg/kg), dichlorvos (0.189 mg/kg), fenvalerate (0.057 mg/kg) and Tumakuru samples recorded phorate (0.072 mg/kg) residues higher than MRLs (Maximum residue levels). Chlorpyrifos, cyhalothrin-g and cypermethrin were below detection level (BDL) in all the samples. Cyfluthrin-β recorded highest in Kunigal samples (0.294 mg/kg), Tumakuru and Gubbi samples showed BDL. Deltamethrin was highest in Pavagada (0.296 mg/kg) samples and Tumakuru and Kunigal samples revealed BDL. Pavagada samples (0.026 mg/kg) showed monocrotophos residues higher than MRLs. In capsicum samples, acephate residue was highest in Tumakuru samples (0.333 mg/kg), highest chlorpyrifos (0.153 mg/kg) in Kunigal samples, deltamethrin (0.381 mg/kg), fenvalerate (0.168 mg/kg) and phorate (0.089 mg/kg) residues were higher than MRLs in Pavagada samples. Cyfluthrin-β (0.045 mg/kg) was high in Tumakuru and dichlorvos (0.042 mg/kg) high in Pavagada samples. Cyhalothrin-g, cypermethrin and monocrotophos were BDL in all the samples. An attempt has been made to assess the different pesticides usage and their adverse impacts on vegetables, which are backbone to afford assistance for an extensive array of investigators.

Organochlorine Pesticide Residue Levels in Kola Nuts (Cola nitida Schott & Endl.) and Estimation of Risk Exposition in Côte d’Ivoire

Background: The kola nut represents a significant economic interest for Côte d’Ivoire as well as many households and public authorities. Despite its obvious importance, the kola nut sector is facing a delicate sanitary quality of the marketed product. About 90% of produced kolanut is consumed daily fresh by people and poses a serious organochlorine pesticide toxicity health problem for consumers. Aims: This study aimed to determine the organochlorine pesticide residue levels in kola nuts and assess the risks of kola nuts consumption on population health in Côte d'Ivoire. Study Design: Samples were collected from Farmers, rural Collectors, urban Stores in Districts (Mountains, Comoe, Lagoons, Down-Sassandra) and big storage Centers of Anyama and Bouake for three separate periods of kola nuts harvesting (2016-2017 ; 2017-2018 and 2018-2019). Methodology: Concentrations of 24 organochlorine pesticide (OCPs) residues were measured using a gas chromatograph equipped with an electron capture detector. Results: The OCPs concentrations ranging from 5.19 to 92.93 µg/kg for Aldrin and Lindane. The results indicate that Methoxychlor, DDE (op'), Endrin ketone, Hexachlorobenzene, Chlorfenapyr, Chlorthal dimethyl and Quitozene concentrations are below the quantification limit (LOQ). Based on the concentrations and the daily consumption of kola nuts estimated at 0.6 g/person in Côte d'Ivoire, the intakes values estimated of OCPs vary from 5.4.10-5 to 7.96.10-4 µg/kg/day for Aldrin and Lindane, respectively. The Exposure Daily Doses (EDD) are all lower than the toxicological reference values. Thus, the occurrence of a toxic effect from OCPs after kola nuts consumption is very unlikely since the hazard quotient HQ sum is less than 1 (∑HQ = 0.13 < 1). Consumption of kola nuts from Côte d’Ivoire does not pose a health risk to consumers. Conclusion: Kola nuts would not represent a health risk for humans and would be safe for comsumption.