Pyrethroid Residues Research Articles

Simultaneous Determination of Pyrethroids Residues in Green Tea Leaves, Processed Tea, Tea Infusion and Spent Tea Leaves

A simple method for the simultaneous determination of pyrethroids residues in green tea leaves, processed tea, tea infusion and spent tea leaves is reported. The target analytes were extracted from selected tea matrices with ethyl acetate followed by dispersive solid phase extraction (d-SPE) based on QuEChERS procedure of clean up with primary secondary amine sorbent to remove co-extractives prior to analysis by gas chromatography with electron capture detector (GC-ECD). The recoveries ranged from 76 to 106 per cent with relative standard deviations below 11 per cent. The limits of quantification for pyrethroids ranged from 0.01 to 0.05 μg g−1. The method was successfully applied to analyse residues of pyrethroids insecticides in actual processed tea samples.

Magnetic Zink-based metal organic framework as advance and recyclable adsorbent for the extraction of trace pyrethroids

Core-shell structured magnetic framework composites (Fe3O4@TMU-21) were fabricated via a facile approach and applied as an effective adsorbent for magnetic solid-phase extraction (MSPE) of trace pyrethroid residues from fruit juice samples. Magnetic framework composites (MFCs) were synthesized via a step-by-step assembly, novel, simple and efficient strategy. The fabricated MFCs showed a high magnetization saturation, accessible sites and good adsorption performance. By coupling MSPE with high-performance liquid chromatography–ultraviolet detection (HPLC-UV), a simple, fast, sensitive, reliable, and cost-effective method for simultaneous determination of trace pyrethroid residues was established successfully. Under optimal conditions, excellent linearity was obtained in the range of 0.5–250 μg L−1, with correlation coefficients R2 > 0.99 and the limits of detection was ranged between 0.1 and 0.05 μg L−1 (based on S/N = 3). Preconcentration factors (PF) and relative recoveries (RR) of the target analytes were obtained in the range of 463–498 and 93.0–104.5% respectively. The precision of the method expressed as a relative standard deviation (RSD) for extraction and determination of the 100 μg L−1 pyrethroid residues in the samples solution was in the range of 3.1–4.4%. The results demonstrate that magnetic Fe3O4@TMU-21 core-shell are the promising sorbents for rapid and efficient extraction of pyrethroid residues from fruit juice samples.

Metal Organic Framework-Molecularly Imprinted Polymer as Adsorbent in Matrix Solid Phase Dispersion for Pyrethroids Residue Extraction from Wheat

Metal organic frameworks-molecular imprinting polymers (MOFs-MIPs) were applied as dispersants of matrix solid phase dispersion (MSPD) followed by gas chromatography-tandem mass spectrometry (GC-MS/MS) to selectively analyze pyrethroids in wheat. MOFs-MIPs characterized by a series of instrumental techniques and the adsorption properties researched by isothermal, kinetics, thermodynamics, and selective binding experiments. The results revealed that the MOFs-MIPs had a larger adsorption capacity (474.56 mg g−1) and fast adsorption time (20 min). What is more, MOFs-MIPs-MSPD procedure clearly increased extraction efficiency and decreased the consumption of organic solvent. The better recoveries of pyrethroids were reached by optimizing MSPD conditions. Under the excellent conditions, the linearity ranges of pyrethroids in wheat samples were obtained varying from 10 to 1000 ng g−1; the limits of detection were in the range of 1.8–2.8 ng g−1 and the precisions were lower than 6.3%. At the same time, the method was successfully applied for detection of three pyrethroids residue in six kinds of wheat samples and cyhalothrin residue detected in one wheat was 23.96 ng g−1, which is lower than the maximum residue limits allowed by the Ministry of Agriculture of the People’s Republic of China. The developed MOFs-MIPs-MSPD-GC-MS/MS method displayed high selectivity, absorbability, simplicity, rapidity, sensitivity, and excellent practical food control applicability.

A dispersive magnetic solid phase microextraction based on ionic liquid-coated and cyclodextrin-functionalized magnetic core dendrimer nanocomposites for the determination of pyrethroids in juice samples

A novel dispersive magnetic solid phase microextraction method based on ionic liquid-coated and cyclodextrin-functionalized magnetic core dendrimer nanocomposites has been developed for the determination of pyrethroids in juice samples. The different generation magnetic core dendrimer nanocomposites were successfully synthesized and the nanocomposites possess both the selective retention of guest dendrimer and cyclodextrin molecules and high adsorption capacities of ionic liquids. The extraction efficiencies of different generation magnetic core dendrimer nanocomposites were compared, and the type of nanocomposite with the highest recovery was obtained. Under the optimized experimental conditions, the method showed good linearity in the range of 3.5–500 μg L−1. The LODs and LOQs were in the ranges of 0.36–1.3 μg L−1 and 1.2–4.3 μg L−1, respectively. The method also showed acceptable accuracies ranging from 98.2% to 99.4%. The proposed method was demonstrated to broaden the potential applications of dendrimer for the detection of pyrethroid residues in various juice samples.

In vitro assessment of pyrethroid bioaccessibility via particle ingestion

Due to their intensive use in agricultural and residential pest control, human exposure to residues of multiple pyrethroids frequently occurs. Pyrethroids have exceptionally high affinity for solid particles, highlighting the need to understand human exposure through oral ingestion of contaminated soil or dust particles. In this study, we used artificial gastrointestinal fluids to measure the desorption or bioaccessibility of eight current-use pyrethroids in soil and dust samples. Tenax was further included as a sink in parallel treatments to simulate the effect of removal due to transfer of pyrethroids to lipid membranes. The use of 0.4 g of Tenax in 20 mL digestive fluids resulted in rapid and efficient trapping of pyrethroids, and further, greatly increased bioaccessibility. In the artificial digestive fluids without Tenax, 6.0–48.0% of pyrethroids were desorbed over 21 h, and the fractions increased by 1.6–4.1 folds to 21.5–79.3% with the Tenax sink. Therefore, 6.0–79.3% of soil or dust-borne pyrethroids may be considered bioavailable upon ingestion. While protein and sucrose increased the estimated bioaccessibility, co-presence of lipid (vegetable oil) decreased the bioaccessibility of pyrethroids, likely due to competitive phase partition. Pyrethroids were also found to be unstable in the artificial intestinal fluid containing pancreatin, further decreasing the potential bioaccessibility of pyrethroids on soil or dust particles. The limited bioaccessibility should be considered to refine the prediction of human exposure and risk through oral ingestion of pyrethroid residues.

Ionic liquid-type surfactant modified attapulgite as a novel and efficient dispersive solid phase material for fast determination of pyrethroids in tea drinks

In this study, a novel ionic liquid-type surfactant modified attapulgite named as 1-dodecyl-3-methylimidazolium bromide-attapulgite (C12MIM-ATP) is successfully prepared and applied in dispersive solid phase extraction (dSPE) for the fast determination of pyrethroid residues in tea drinks. The primary factors that influenced the extraction efficiency, including sorbent type, amount of sorbent, extraction time, desorption conditions, pH and ionic strength, are investigated. The optimized results reveal that the extraction and desorption equilibria are rapidly obtained within 1 min. Under the optimized conditions, good linearity (2–500 μg/L) is observed for four pyrethroids in tea drinks with determination coefficients (r2) ranged from 0.9992 to 1.0000. The limits of detection (LODs) are 0.6 μg/L for all pesticides. Acceptable extraction recoveries of target analytes are found from 90.28 to 107.56% with relative standard deviations (RSDs) less than 8.30% in real tea drink samples. The batch-to-bath repeatability is evaluated by recovery test on five independent synthesized C12MIM-ATP sorbents. Satisfactory batch-to-batch repeatability is obtained with the recovery factors varied in 15%. A small matrix effect is observed using C12MIM-ATP as the sorbent for detection pyrethroids in tea drinks.

Dissipation and Migration of Pyrethroids in Auricularia polytricha Mont. from Cultivation to Postharvest Processing and Dietary Risk.

In order to ensure raw consumption safety the dissipation behavior, migration, postharvest processing, and dietary risk assessment of five pyrethroids in mushroom (Auricularia polytricha Mont.) cultivated under Chinese greenhouse-field conditions. Half-lives (t1/2) of pyrethroids in fruiting body and substrate samples were 3.10–5.26 and 17.46–40.06 d, respectively. Fenpropathrin dissipated rapidly in fruiting bodies (t1/2 3.10 d); bifenthrin had the longest t1/2. At harvest, pyrethroid residues in A. polytricha (except fenpropathrin) were above the respective maximum residue limits (MRLs). Some migration of lambda-cyhalothrin was observed in the substrate-fruit body system. In postharvest-processing, sun-drying and soaking reduced pyrethroid residues by 25–83%. We therefore recommend that consumers soak these mushrooms in 0.5% NaHCO3 at 50 °C for 90 min. Pyrethroids exhibit a particularly low PF value of 0.08–0.13%, resulting in a negligible exposure risk upon mushroom consumption. This study provides guidance for the safe application of pyrethroids to edible fungi, and for the establishment of MRLs in mushrooms to reduce pesticide exposure in humans.

Pyrethroid residue dynamics in insects depends on the circadian clock

ABSTRACTMany factors may affect pesticide effectiveness against pests. One of the factors that should be considered is circadian rhythmicity. In this study, we evaluated daily variations in pyrethroid susceptibility in the house cricket, Acheta domesticus L. Crickets were exposed to a standard dose of ß-cyfluthrin at different times of a day, and pesticide residue levels were evaluated using gas chromatography. Results demonstrate that the time of pyrethroid disappearance is correlated with the circadian clock, with the highest decomposition rate at night. Furthermore, crickets also showed the highest resistance to the insecticide at night, expressed as a high survival rate. Moreover, ß-cyfluthrin induced significant changes in thermal preferences of intoxicated crickets. This is the first report showing that pyrethroid residue levels in the crickets' body depend on its circadian clock.

Pest Prevalence and Evaluation of Community-Wide Integrated Pest Management for Reducing Cockroach Infestations and Indoor Insecticide Residues.

Pest infestations in residential buildings are common, but community-wide pest survey data are lacking. Frequent insecticide applications for controlling indoor pests leave insecticide residues and pose potential health risks to residents. In this study, a community-wide pest survey was carried out in a housing complex consisting of 258 units in 40 buildings in New Brunswick, New Jersey. It was immediately followed by implementation of an integrated pest management (IPM) program in all the cockroach-infested apartments and two bed bug apartments with the goal of eliminating pest infestations, reducing pyrethroid residues, and increasing resident satisfaction with pest control services. The IPM-treated apartments were revisited and treated biweekly or monthly for 7 mo. Initial inspection found the top three pests and their infestation rates to be as follows: German cockroaches (Blattella germanica L. [Blattodea: Blattellidae]), 28%; rodents, 11%; and bed bugs (Cimex lectularius L. [Hemiptera: Cimicidae]), 8%. Floor wipe samples were collected in the kitchens and bedrooms of 20 apartments for pyrethroid residue analysis before the IPM implementation; 17 of the 20 apartments were resampled again at 7 mo. The IPM program reduced cockroach counts per apartment by 88% at 7 wk after initial treatment. At 7 mo, 85% of the cockroach infestations found in the initial survey were eliminated. The average number of pyrethroids detected decreased significantly from 6 ± 1 (mean ± SEM) and 5 ± 1 to 2 ± 1 and 3 ± 1 in the kitchens and bedrooms, respectively. The average concentrations of targeted pyrethroids residue also decreased significantly in the kitchens and bedrooms.

Developments on Immunoassays for Pyrethroid Chemicals

Pyrethroids exist in numerous commercial insecticide formulations and have been used extensively all over the globe for pest control indoors and outdoors in many fields such as agriculture, public health, home use, and veterinary applications. The use of pyrethroids has increased continuously in recent years. This review aims to provide the latest research progress on newly developed haptens and antibodies, as well as their main applications in monitoring pyrethroid residues in the medical, environmental and agricultural fields. Two types of haptens were designed for pyrethroid insecticides. One recognized only a specific pyrethroid insecticide, whereas the other detected a series of pyrethroid insecticides with common molecular structures. Haptens and their conjugates were prepared to produce either monoclonal or polyclonal antibodies. The literature reviews have shown that a major trend for using enzyme immunoassay (EIA) methods to detect pyrethroid pesticide residues is to design universal immune haptens and prepare selective broad-spectrum antibodies. Besides, to develop immune detection methods for pyrethroid residues is an important research and development topic for monitoring the quality and safety of agricultural products worldwide. Keywords: Pyrethroid chemicals, hapten, antibody, immunoassay, medical fields, environmental and agricultural fields.

Determination of Pyrethroids in Tea Brew by GC-MS Combined with SPME with Multiwalled Carbon Nanotube Coated Fiber

A new method has been developed to simultaneously determine 7 pyrethroid residues in tea brew using gas chromatography-mass spectrometry (GC-MS) combined with solid phase microextraction (SPME) with multiwalled carbon nanotubes (MWCNTs) coated fiber. The MWCNTs coated fiber of SPME was homemade by using stainless steel wire as coating carrier and polyacrylonitrile (PAN) solution as adhesive glue. Under the optimized conditions, a good linearity was shown for bifenthrin, fenpropathrin, permethrin, and cyfluthrin in 1–50 ng mL−1 and for cypermethrin, fenvalerate, and deltamethrin in 5–50 ng mL−1. The correlation coefficients were in the range of 0.9948–0.9999. The average recoveries of 7 pyrethroids were 94.2%–107.3% and the relative standard deviations (RSDs) were less than 15%. The detection limit of the method ranged from 0.12 to 1.65 ng mL−1. The tea brew samples made from some commercial tea samples were analyzed. Among them, bifenthrin, fenpropathrin, and permethrin were found. The results show that the method is rapid and sensitive and requires low organic reagent consumption, which can be well used for the detection of the pyrethroids in tea brew.

Quantification of Pyrethroid Residue in Food, Agricultural and Biological Samples

Quantification of Pyrethroid Residue in Food, Agricultural and Biological Samples

Determination of pyrethrin and pyrethroid residues in animal fat using liquid chromatography coupled to tandem mass spectrometry

A method was developed for the confirmatory and quantitative analysis of one pyrethrin and 18 pyrethroid residues in animal fat. Fat was extracted was collected from adipose tissue melted in an oven at 65 °C for 2 h. Fat samples (1 g) were dispersed with deactivated Florisil® sorbent and extracted with MeCN. Sample extracts were purified by cold temperature precipitation at −30 °C for 4 h and further purified using dispersive solid-phase extraction (d-SPE) clean-up in tubes containing 500 mg of Z-SEP+ and 125 mg of PSA bonded silica. Purified samples were analysed by ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC–MS/MS) detection. Chromatographic separation was carried out on a Acquity C8 BEH column, using a binary gradient separation comprising of mobile phase A, 5 mM ammonium formate in water:MeOH (80:20, v/v,) and mobile phase B, 5 mM ammonium formate in MeOH. The mass spectrometer was operated in the positive electrospray ionisation mode (ESI(+)). Validation was performed following the 2002/657/EC guidelines. Trueness ranged between 84% and 143% and precision ranged between 3.9% and 29%. The developed method is particularly advantageous because the sample preparation procedure does not require complex sample extraction equipment and uses less solvent compared to other sample preparation protocols.

Comparative study of pyrethroids residue in fruit peels and fleshes using polystyrene-coated magnetic nanoparticles based clean-up techniques

An efficient and rapid method for quantifying pyrethroids pesticide residue in fruits samples was developed in the present study. The application of lab prepared polystyrene magnetic nanoparticles based magnetic solid phase extraction technique combined with liquid-solid extraction helped clean-up the sample and preconcentrate the targeted analytes prior to HPLC quantification. The lab prepared nanoparticles were characterised with Fourier transform infrared spectroscopy, atomic force microscopy, X-ray diffraction spectroscopy, as well as vibrating sample magnetometer to study their size, morphology, crystal structure, functional groups and magnetism properties, respectively. Afterwards, optimisation of the parameters affecting extraction efficiency was carried out in order to achieve optimum conditions for extracting pyrethroids residue from fruit samples. Analytical performances were evaluated by carrying out experiments at optimum conditions. Results showed that the limit of detection and limit of quantification were below 0.1445 and 0.5116 ng g−1, respectively for the six pyrethroids tested. The recovery rates were within the range of 73.6%–123.1% with intra-day and inter-day relative standard deviation being less than 16.5% and 15.4%, respectively, suggesting satisfactory reproducibility of the proposed method. Real sample analysis was performed using 6 kinds of commonly consumed fruits obtained from local supermarkets in Singapore, including apples, pears, oranges, lemons, grapes and nectarines. The peel and flesh were tested separately to study the difference of pyrethroids residue in different parts of fruits. The grape sample tested was detected with permethrin residue on its peel. There was no violation since the permethrin amount detected was way much lower than the maximum residue limit set by local government.

A LIQUID CHROMATOGRAPHY METHOD FOR DETERMINATION OF PYRETHROIDS INSECTICIDES RESIDUES IN BEANS

A rapid liquid chromatographic (LC) method was developed for simultaneous determination of 7 pyrethroid insecticides in beans. Residues were extracted from beans with acetone, followed by partition with ethyl acetate/cyclohexane (1+1) and clean up by gel-permeation chromatography. LC separation was performed on a LiChrospher 100 RP-18 column using acetonitrile/water (8+2) as mobile phase. The pesticides were detected by molecular absorption spectrophotometry at 212 nm. Recoveries of 7 pyrethroids fortified at 0.010; 0.10; 1.0 mg kg-1 levels were within the range 71-105 %. Advantageous features of this method are: the quantification limits, which were between 0.004 and 0.011 mg kg-1, and the simplicity in the sample treatment, which requires less clean-up if compared with the GC-ECD determination. No residues of pyrethroids were detected in 48 bean samples commercialized in São Paulo City during 2008.

Residual degradation and toxicity of insecticides against Bactrocera oleae.

Field and lab trials took place in Crete (July to September 2016), concerning the residual degradation and toxicity of seven active ingredients applied as bait sprays against the olive fruit fly. Highest residues were recorded in olive leaves for dimethoate and phosmet (~60mg/kg) immediately after application (day 1+), while a threefold and fivefold reduction was observed 1week later, respectively. Residues of pyrethroids were determined at lower levels (<10mg/kg) but remained almost stable for a longer period of time. Finally, thiacloprid and spinosad residues were determined at 5.81 and 0.19mg/kg respectively (day 1+), and rapidly decreased below the LOQ. Highest toxicity against the olive fruit fly was observed just right after the application of dimethoate (100%), a-cypermethrin (80%), and L-cyhalothrin (72.92%). Although the toxicity of dimethoate was significantly reduced 1week after the application (80%) and then minimized, toxicity of pyrethroids remained almost stable (>60%) for the first 2weeks and then decreased to 30-40%, which remained stable up to the end of the study (8weeks). Concerning phosmet, its toxicity ranged from 35 to 56% for 3weeks with no significant reduction, while spinosad presented a lower toxicity profile (50% only for 1week). The benefits of these results in the knowledge of insecticide residues and their toxicity against olive fruit fly can be used for improving olive fruit fly control.

Factors Affecting Transfer of Pyrethroid Residues from Herbal Teas to Infusion and Influence of Physicochemical Properties of Pesticides.

The transfer of pesticide residues from herbal teas to their infusion is a subject of particular interest. In this study, a multi-residue analytical method for the determination of pyrethroids (fenpropathrin, beta-cypermethrin, lambda-cyhalothrin, and fenvalerate) in honeysuckle, chrysanthemum, wolfberry, and licorice and their infusion samples was validated. The transfer of pyrethroid residues from tea to infusion was investigated at different water temperatures, tea/water ratios, and infusion intervals/times. The results show that low amounts (0–6.70%) of pyrethroids were transferred under the different tea brewing conditions examined, indicating that the infusion process reduced the pyrethroid content in the extracted liquid by over 90%. Similar results were obtained for the different tea varieties, and pesticides with high water solubility and low octanol–water partition coefficients (log Kow) exhibited high transfer rates. Moreover, the estimated values of the exposure risk to the pyrethroids were in the range of 0.0022–0.33, indicating that the daily intake of the four pyrethroid residues from herbal tea can be regarded as safe. The present results can support the identification of suitable tea brewing conditions for significantly reducing the pesticide residue levels in the infusion.

DEVELOPMENT OF ANALYTICAL METHOD FOR THE DETERMINATION OF TRIAZOLE AND PYRETROID PESTICDES IN MUSTARD GREENS (Brassicajuncea)

&lt;p&gt;&lt;strong&gt;Abstract&lt;/strong&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p&gt; Triazole and pyrethroid are two of the most commonly used pesticides in vegetable cultivation recently. In this study, a multi-residue analytical method employing gas chromatography – mass spectromety (GC-MS) technique was successfully developed for quantification of two triazole fungicides including propiconaozle and difenoconazole and on pyrethroid insecticide cypermethrin (including 04 isomeres) in mustard greens. The GC-MS running program performed good separation, low detection limit and short analysis time (24 minutes). Target compounds in mustard green sample were ultrasonically extracted in 15 minutes by 60 mL acetone, followed by clean-up steps using solid phase extraction of packed activated carbon column with 40 mL acetone:toluene (v:v, 1:1) for elutions, and florisil cartridge with an elution mixture of 15 mL acetone:n-hexane (v:v, 1:5). The method was validated before applying for a preliminary screening of triazole and pyrethroid residue levels in mustard greens collected in Phu Yen Province, Vietnam.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;&lt;em&gt;Keywords:&lt;/em&gt;&lt;/strong&gt; triazole, pyrethroid, residues in vegetables, GC-MS&lt;/p&gt;

Identification and immobilization of a novel cold-adapted esterase, and its potential for bioremediation of pyrethroid-contaminated vegetables

BackgroundPyrethroids are potentially harmful to living organisms and ecosystems. Thus, concerns have been raised about pyrethroid residues and their persistence in agricultural products. To date, although several pyrethroid-hydrolyzing enzymes have been cloned, very few reports are available on pyrethroid-hydrolyzing enzymes with cold adaptation, high hydrolytic activity and good reusability, indispensable properties in practical bioremediation of pyrethroid-contaminated vegetables.ResultsHere, a novel gene (est684) encoding pyrethroid-hydrolyzing esterase was isolated from the Mao-tofu metagenome for the first time. Est684 encoded a protein of 227 amino acids and was expressed in Escherichia coli BL21 (DE3) in soluble form. The optimum temperature was 18 °C. It maintained 46.1% of activity at 0 °C and over 50% of its maximal activity at 4–35 °C. With the goal of enhancing stability and recycling biocatalysts, we used mesoporous silica SBA-15 as a nanometer carrier for the efficient immobilization of Est684 by the absorption method. The best conditions were an esterase-to-silica ratio of 0.96 mg/g (w/w) and an adsorption time of 30 min at 10 °C. Under these conditions, the recovery of enzyme activity was 81.3%. A large improvement in the thermostability of Est684 was achieved. The half-life (T1/2) of the immobilized enzyme at 35 °C was 6 h, 4 times longer than the soluble enzyme. Interestingly, the immobilized Est684 had less loss in enzyme activity up to 12 consecutive cycles, and it retained nearly 54% of its activity after 28 cycles, indicating excellent operational stability. Another noteworthy characteristic was its high catalytic activity. It efficiently hydrolyzed cyhalothrin, cypermethrin, and fenvalreate in pyrethroid-contaminated cucumber within 5 min, reaching over 85% degradation efficiency after four cycles.ConclusionsA novel cold-adapted pyrethroid-hydrolyzing esterase was screened from the Mao-tofu metagenome. This report is the first on immobilizing pyrethroid-hydrolyzing enzyme on mesoporous silica. The immobilized enzyme with high hydrolytic activity and outstanding reusability has a remarkable potential for bioremediation of pyrethroid-contaminated vegetables, and it is proposed as an industrial enzyme.

Health risks due to consumption of pesticides in ready-to-eat vegetables (salads) in Kumasi, Ghana

BackgroundPesticide residue levels were determined in ready-to-eat vegetables collected from 16 sites along the food chain; which is, farms, markets, cafeterias and street food vending sites in Kumasi, Ghana. The aim of the study was to determine the concentrations of pesticides residues in two ready-to-eat vegetables and assess the health risks due to consumption of these contaminated vegetables.MethodsPesticide residues in ready-to-eat vegetables or salads were extracted by means of the QuEChERS method. Synthetic pyrethroid and organophosphorus pesticides residues in samples were determined using Gas Chromatography with Electron Capture Detector and Pulsed Flame Photometric Detector respectively. Consumption data of ready-to-eat vegetables were obtained from a questionnaire-based dietary survey in the study area. The hazard index and the relative potency factor (RPFs) approaches were used to assess the health risk from chronic cumulative dietary exposure to pesticides.ResultsThere were six synthetic pyrethroid residues detected in the ready-to-eat samples at varying concentrations. They were bifenthrin, permethrin, cypermethrin, deltamethrin, lambda-cyhalothrin and fenvalerate. Also, two organophosphates were detected in the samples; which were chlorpyrifos and diazinon. Lambda-cyhalothrin residues was present in all the samples in the study, with the mean concentration of 4.5 × 10−2 mgkg−1. The mean concentration of diazinon in all the samples (0.040 mgkg−1) exceeded the EU MRLs (0.01 mgkg−1), chlopyrifos exceeded its MRL in one sample from the street food vending site and cafeteria each. Deltamethrin, Fenvalerate and Permethrin exceeded their respective MRL in samples from Asafo (Street food vending sites) and Adum (Cafeteria) and KNUST (Farm) respectively. However, the health index of all pesticides residues detected were below the permissible limit. The cumulative intake from the RPF approach for the pesticides were relatively lower than the ADI of the index chemicals.ConclusionThe concentrations of chlorpyrifos, deltamethrin, fenvalerate, diazinon and permethrin exceeded their respective EU MRLs in some ready-to-eat vegetable samples in the study. The health index and comparison of cumulative intake from RPF with ADI of the index chemicals suggest that pesticide residues in ready-to-eat vegetables could not be considered a major public health problem.