Cypermethrin Residues Research Articles

Parasiticidal Properties of Nanoemulsion-Based Plant Essential Oil Formulations for Controlling Poultry Ectoparasites in Farm Conditions

Nanoemulsion-based plant essential oil formulations (NEOFs) have shown remarkable parasiticidal properties in laboratory settings, suggesting the potential for practical farm applications. This study investigates the efficacy of NEOFs—comprising clove and cinnamon essential oils (EOs)—in controlling poultry ectoparasites under real farm conditions. We evaluated the impact of NEOFs on ectoparasite populations, egg-laying performance, egg quality, leukocyte profiles in chicken blood, and potential insecticide residues in eggs. Conducted across various poultry farms, the results revealed that NEOFs achieved an over 95% ectoparasite eradication after two treatments, compared to significantly higher ectoparasite populations in untreated control groups. Egg production was notably higher in NEOF-treated flocks, and the feed conversion ratio was improved. No significant differences in leukocyte profiles were observed between the treated and control groups. In contrast, cypermethrin residues were detectable in eggs for more than eight weeks post-treatment. NEOFs achieved an over 97% ectoparasite extermination within seven days post-treatment, with farmer satisfaction averaging 4.83 out of 5.00. These findings position NEOFs as a highly effective, environmentally friendly alternative to chemical pesticides for managing poultry ectoparasites, offering a viable solution for sustainable poultry farming.

The effect of different washing methods assisted by ultrasound on the removal of cypermethrin and spirotetramat residues in apples

AbstractThe simplest way to remove pesticide residues from fruits and vegetables is to wash them with tap water. However, this method is not effective enough. In this study, the effectiveness of different washing methods assisted by ultrasound on pesticide removal was investigated. For this purpose firstly, apples were soaked in a cypermethrin (CYP) and spirotetramat (SPI) solution, which are frequently used as insecticides. Subsequently, the apples were washed in solutions prepared with vinegar, lemon juice, and baking soda at different concentrations (0.5%, 1% and 2%) and assisted by ultrasound (2.5–5 min). The residues in the medicated and washed samples were analysed on an LC-MS/MS instrument after extraction using the QuEChERS extraction method. The results of the analysis showed that acidic vinegar and lemon juice were more effective than baking soda. Moreover, the application of ultrasound significantly increased this effect. When a 0.5% vinegar solution was assisted by ultrasound, 62% of the cypermethrin residue was removed and 82% of the spirotetramat residue was removed. These values were 51.5% and 49.6% higher than tap water, respectively. In conclusion, acidic solutions such as vinegar, which we can easily prepare at home, are highly effective in removing pesticide residues when assisted by ultrasound.

Effect of ozone, hydrogen peroxide, and chlorine solution in reduction of chlorpyrifos and cypermethrin residues from cauliflower

The extensive utilization of chlorpyrifos and cypermethrin in agriculture raises concerns regarding the accumulation of pesticide residues in human food, posing a threat to human health. This study aimed to investigate the effect of ozonation on cauliflower to decrease the level of pesticides. Cypermethrin and organophosphate chlorpyrifos were applied to cauliflower at specific doses. High-performance liquid chromatographic techniques were employed to detect pesticide residues in cauliflower. The effects of common oxidizers (hydrogen peroxide, chlorine, and ozone) on the reduction of pesticide residues were investigated. Solutions of hydrogen peroxide (10 and 100 ppm), chlorine (10 and 100 ppm), and ozone (10 and 100 ppm) were prepared, and the cauliflower sample was immersed for 20 min. The immersion in 10 ppm hydrogen peroxide solution reduced chlorpyrifos and cypermethrin by 68 and 65%, respectively. Meanwhile, at 100 ppm hydrogen peroxide solution, the reduction rates of chlorpyrifos and cypermethrin residues were 72 and 75%, respectively. Immersion in ozone solution at 10 ppm concentration reduced chlorpyrifos and cypermethrin by 58 and 57%, respectively. At 100 ppm ozone, chlorpyrifos was reduced up to 64%, and cypermethrin reduction was 74%. Chlorine immersion at 10 ppm reduced chlorpyrifos residues by 68% and cypermethrin residues by 81%, while a 100 ppm chlorine solution reduced chlorpyrifos residues by 100% and cypermethrin residues by 84%. From these results, it was concluded that chlorine was the most effective of all the cleaning solutions to remove pesticides from vegetables.

Dissipation behaviour and dietary risk evaluation of pesticides on cucumber.

Cucumber (Cucumis sativus L.) is the world's most widely consumed salad vegetable, and it is frequently treated with pesticides to prevent pest and disease outbreaks. Pesticide residues in food commodities impede trade and pose a major health risk. Prior to residue estimation, the QuEChERS approach was validated utilising criteria such as limit of detection, limit of quantitation, linearity, accuracy, and precision. The residues of carbendazim, cypermethrin, ethion, profenofos, quinalphos, and triazophos were examined using a Gas Chromatograph equipped with an Electron Capture Detector or a Flame Photometric Detector and a high-performance liquid chromatography coupled to a photo diode array. The initial deposits of carbendazim, cypermethrin, ethion, profenofos, quinalphos, and triazophos at the prescribed dose were 1.235, 0.407, 0.817, 0.960, 0.628, and 0.985mg/kg, respectively, with a pre-harvest interval of 5.58-11.30days. According to the consumer risk evaluation data, the Hazard Quotient is less than one, and the Theoretical Maximum Dietary Intake is less than the Maximum Permissible Intake and Maximum Residue Limit, both of which are considered safe for human consumption at the authorised dose.

Diffusion of organochlorine (OCPs) and cypermethrin pesticides from rohu (Labeo rohita) internal organs to edible tissues during ice storage: a threat to human health.

The migration of organochlorine pesticides (OCPs) and cypermethrin residues from internal organs to edible tissues of ice-held Labeo rohita (rohu) was investigated in this study. The liver (246µg/kg) had the highest level of ∑OCP residues, followed by the gills (226µg/kg), intestine (167µg/kg), and muscle tissue (54µg/kg). The predominant OCPs in the liver and gut were endosulfan (53-66µg/kg), endrin (45-53µg/kg), and dichloro-diphenyl-trichloroethane (DDT; 26-35µg/kg). The ∑OCP residues in muscle increased to 152µg/kg when the entire rohu was stored in ice, but they decreased to 129µg/kg in gill tissues. On days 5 and 9, the total OCPs in the liver increased to 317µg/kg and 933µg/kg, respectively. Beyond day 5 of storage, total internal organ disintegration had led to an abnormal increase in OCP residues of liver-like mass. Despite a threefold increase in overall OCP residues by day 9, accumulation of benzene hexachloride (BHC) and heptachlor was sixfold, endrin and DDT were fourfold, aldrin was threefold, and endosulfan and cypermethrin were both twofold. Endosulfan, DDT, endrin, and heptachlor were similarly lost in the gills at a rate of 40%, while aldrin and BHC were also lost at 60 and 30%, respectively. The accumulation of OCP residues in tissues has been attributed to particular types of fatty acid derivatives. The study concluded that while pesticide diffusion to edible tissues can occur during ice storage, the levels observed were well below the allowable limit for endosulfan, endrin, and DDT.

Dissipation and evaluation of different treatments on the residues of different insecticides in/on cauliflower curd

A field study to understand dissipation rates and effect of various washing treatments on the residues of seven different insecticides, i.e. tetraniliprole 200 SC, emamectin benzoate 5 SG, lufenuron 5.4 EC, indoxacarb 14.5 SC, thiodicarb 75 WP, profenofos 50 EC and cypermethrin 25 EC in/on cauliflower curd has been conducted. The results showed that initial deposits (just after the last insecticide application, i.e. 0 d) of tetraniliprole, emamectin benzoate, lufenuron, indoxacarb, thiodicarb, profenofos and cypermethrin were 0.43, 0.03, 0.25, 0.28, 0.38, 6.70 and 0.68 mg kg−1, respectively. The dissipation pattern of all the tested insecticides followed monophasic, first order kinetics with the half-lives of 6.25, 8.85, 3.27, 7.71, 4.36, 2.98 and 3.76 d, respectively. Proposed pre-harvest intervals for these insecticides are 6, 9, 3, 8, 4, 3 and 4 d, respectively. All the decontamination techniques showed reductions in residue levels. However, treatment by soaking in 5% sodium bicarbonate aqueous solution showed 54%, 42%, 53%, 48%, 22%, 54% and 77% maximum reductions in residues of tetraniliprole, emamectin benzoate, lufenuron, indoxacarb, profenofos and cypermethrin, respectively, in cauliflower curds. The next best treatment was soaking cauliflower curds in water at 45–50 °C for 10 min, which reduced the residues of cypermethrin, profenofos, tetraniliprole, thiodicarb, emamectin benzoate and lufenuron.

Detection of toxic cypermethrin pesticides in drinking water by simple graphitic electrode modified with Kraft lignin@Ni@g-C3N4 nano-composite.

The detrimental effects of widespread pesticide application on the health of living organisms highlight the urgent need for technological advancements in monitoring pesticide residues at trace levels. This study involves the synthesis of a distinctive sensing material, KL@Ni@g-C3N4, which comprises nanocomposites of graphitic carbon nitride with Kraft lignin and nickel. The prepared samples were characterized using FT-IR, PXRD, TEM, SEM, and EDX techniques. The KL@Ni@g-C3N4 nanocomposite was drop-cast on a graphite electrode. Subsequently, this fabricated electrode was used to detect cypermethrin (CYP) residues in drinking water. The redox properties of the fabricated sensors were evaluated using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The limit of detection (LOD) of the fabricated sensor was determined to be 0.026 μg mL-1, which is below the maximum residual limits of CYP in the environment (0.5 μg mL-1) and within the acceptable range for food products (∼0.05 to 0.2 μg mL-1). Therefore, this study proposes a promising alternative to conventional methods for detecting pesticides in drinking water.

Cypermethrin adsorption by Lactiplantibacillus plantarum and its behavior in a simulated fecal fermentation model.

The presence of cypermethrin in the environment and food poses a significant threat to human health. Lactic acid bacteria have shown promise as effective absorbents for xenobiotics and well behaved in wide range of applications. This study aimed to characterize the biosorption behavior of cypermethrin by Lactiplantibacillus plantarum RS60, focusing on cellular components, functional groups, kinetics, and isotherms. Results indicated that RS60 exopolysaccharides played a crucial role removing cypermethrin, with the cell wall and protoplast contributing 71.50% and 30.29% to the overall removal, respectively. Notably, peptidoglycans exhibited a high affinity for cypermethrin binding. The presence of various cellular surface groups including -OH, -NH, -CH3, -CH2, -CH, -P = O, and -CO was responsible for the efficient removal of pollutants. Additionally, the biosorption process demonstrated a good fit with pseudo-second-order and Langmuir-Freundlich isotherm. The biosorption of cypermethrin by L. plantarum RS60 involved complex chemical and physical interactions, as well as intraparticle diffusion and film diffusion. RS60 also effectively reduced cypermethrin residues in a fecal fermentation model, highlighting its potential in mitigating cypermethrin exposure in humans and animals. These findings provided valuable insights into the mechanisms underlying cypermethrin biosorption by lactic acid bacteria and supported the advancement of their application in environmental and health-related contexts. KEY POINTS: • Cypermethrin adsorption by L. plantarum was clarified. • Cell wall and protoplast showed cypermethrin binding ability. • L. plantarum can reduce cypermethrin in a fecal fermentation model.

Environmental risks of a commonly used pyrethroid: Insights from temporary pond species of the Lake Manyara Basin, Tanzania

Environmental risks posed by widespread pesticide application have attracted global attention. Currently, chemical risk assessments in aquatic environments rely on extrapolation of toxicity data from classic model species. However, similar assessments based on local species could be complementary, particularly for unusual living environments such as temporary ponds. Here, we carried out an environmental risk assessment (ERA) of a pyrethroid model compound, cypermethrin, based on local temporary pond species. First, we measured cypermethrin residue concentrations in rivers, irrigation canals and temporary ponds in the Lake Manyara Basin (LMB). Then, we estimated the environmental risks of cypermethrin by combining these data with acute toxicity data of three resident species across three trophic levels: primary producers (Arthrospira platensis), invertebrate grazers (Streptocephalus lamellifer) and fish (Nothobranchius neumanni). Furthermore, we compared the derived ERA to that obtained using toxicity data from literature of classic model species. Cypermethrin residue concentrations in contaminated systems of the LMB ranged from 0.01 to 57.9 ng/L. For temporary pond species, S. lamellifer was the most sensitive one with a 96 h-LC50 of 0.14 ng/L. Regardless of the assumed exposure concentration (0.01 and 57.9 ng/L), the estimated risks were low for primary producers and high for invertebrate grazers, both for local species as well as for classic model species. The highest detected cypermethrin concentration resulted in a moderate risk estimation for local fish species, while the estimated risk was high when considering classic fish models. Our results confirm that, at least for pyrethroids, ERAs with classic model species are useful to estimate chemical risks in temporary pond ecosystems, and suggest that complementary ERAs based on local species could help to fine-tune environmental regulations to specific local conditions and conservation targets.

Cypermethrin insecticide residue, water quality and phytoplankton diversity in the lychee plantation catchment area

<abstract> <p>Lychee plantation areas are typically located at varying elevations on mountains to ensure proper drainage. This placement has direct effects on stream and river water flows and consequently influences pesticide residue, water quality and aquatic biodiversity. This research aims to examine the relationships between cypermethrin residue, water quality and phytoplankton diversity in the lychee plantation catchment area in Phayao Province, Thailand, from January to May 2022. The study area was divided into six sampling sites. Water samples were collected for the investigation of cypermethrin residual, physicochemical and biological water quality parameters. The water quality index was used as an overall measurement of water quality. The study also examined the diversity of phytoplankton species and the relationship among cypermethrin residue, water quality and phytoplankton diversity were studied using canonical correspondence analysis. The findings revealed an increasing trend of cypermethrin residue, with the maximum concentration reaching 29.43 mg/L in March. The trend of decreasing water quality scores from Station S1 to Station S5 indicated the influence of land use changes and human activities, especially in the community area (S5), which was characterized by deterioration of water quality. A total of 174 phytoplankton species were categorized into 5 divisions, with Chlorophyta accounting for 61.49% of the total, followed by Bacillariophyta (28.16%) and Cyanophyta (6.32%). The highest Shannon's diversity index and evenness were observed at Stations S3 and S4, respectively. The canonical correspondence analysis revealed an interesting relationship among cypermethrin residue, ammonia nitrogen, chlorophyll a and three algal species: <italic>Pediastrum simplex</italic> var. <italic>echinulatum</italic>, <italic>Pediastrum duplex</italic> var. <italic>duplex</italic> and <italic>Scenedesmus acutus</italic> at Station S3. This research implies that pesticide residue and water quality have a direct impact on phytoplankton distribution, illustrating the environmental challenges that occur in various geographical areas. This information can be applied to assist in the development of future sustainable land use management initiatives.</p> </abstract>

Assessing the Effectiveness of Saponins from Alfalfa (Medicago sativa L.) to Mitigate Cypermethrin Residues in Apples

Pesticide residues on fruits and vegetables are of major health concern around the world. Some of these pesticide residues are extremely toxic and can become a major causative factor for various diseases such as cardiovascular disorders (CVDs), lung, endocrine, and nervous system damage, as well as the circulatory system, and reproductive system problems. This study was aimed at investigating the effectiveness of saponins isolated from alfalfa (Medicago sativa L.) seeds for mitigating cypermethrin residues on apples (Malus domestica Borkh.) in comparison to tap water, citric acid, and baking soda. Cypermethrin concentration applied to apples was 1 ml/L. After washing the apples with varying concentrations of different washing solutions, analysis for cypermethrin residues was performed using a UV/VIS spectrophotometer at a wavelength of 535 nm. The maximal removal of residues recorded for baking soda, tap water, and citric acid was 92.98, 72.50, and 74.59 % respectively. Saponins exhibited a maximum of 13.90 % of residual removal which was not as effective as other washing agents.

Pyrethroids contamination and health risk assessment in seafood collected from the coast of Shandong, China

This study provides the first data on pyrethroid residues of seafood in China. A total of 192 seafood samples were randomly selected from four coastal cities of Shandong Province in 2020. The residues of fenpropathrin, cypermethrin and deltamethrin in seafood by GC–MS were ND to 26.82 μg/kg, ND to 19.18 μg/kg and ND to 15.56 μg/kg, respectively. The cumulative risk to general population of different age groups was assessed by the hazard quotient (HQ) and hazard index (HI) approaches, and showed that the maximum value of both HQ (1.81 × 10−3) and HI (2.9 × 10−3) were below the threshold 1. The present results indicated that the three main pyrethroids from the consumption of seafood is unlikely to pose a health risk to general populations in Shandong. The uncertainty analysis indicated that the monitoring study of pyrethroid residues in seafood is worthy of continuous attention to ensure food safety.

Agrochemical Residues in Soil, Water, Chicken’sBlood and Worker’s Urine Samples in Rose Farms, Tak Province, Thailand

The agrochemical overuse, especially that of paraquat, cypermethrin and carbendazim, has been observed in Thailand. Residuals do not only contaminate the environment and agricultural products, but also other living organisms related to the farming. With less attention being paid to the agrochemical residues in the environment, this study aimed to quantify agrochemical residues in soil, water, chicken’s blood and worker’s urine samples across different periods of cultivation among nine rose farms in Tak Province, Thailand were selected as study sites. Various agrochemicals were used throughout the year; particular attention was paid to paraquat, cypermethrin and carbendazim. Soil and water samples represented the environment, chicken’s blood represented animal subjects, and urine samples of rose farmers represented human subjects. The study revealed the existence of those three agrochemical residues in both soil and water samples. It was only in soil samples that paraquat and cypermethrin concentrations were higher than the maximum allowable concentration (47.24 mg kg-1and 0.24 mg kg-1, respectively). Residues of cypermethrin and carbendazim were found only in chicken’s blood (0.0280 μg L-1 and 0.0750 - 0.1640 μg L-1, respectively). Since rose farmers were well equipped with personal protective equipment when applying the pesticides, paraquat, cypermethrin and carbendazim quantifications in their urine samples were all below the detectable limits of the instruments used. Further studies such as better methods for residue analysis and a larger sample size are needed. More reliable quantifications may possibly result in assessing the relationship between agrochemical residues among environmental and living organisms.

Pathogen and pesticide contamination in cabbage grown from, Dalaguete, Cebu, Philippines

Food safety is one of the long-sought problems in the world. Chemical and biological characteristics must be considered when evaluating the safety of various food products. This study aimed to assess the food safety of cabbages grown from Mantalongon, Dalaguete, Cebu. Cabbage samples acquired from three different farms in Mantalongon were tested for the presence of Salmonella spp. (and other potentially pathogenic bacteria) and pesticide (cypermethrin) residues. To detect the presence of Salmonella spp., pre-enrichment and enrichment methods were done. For the analysis of cypermethrin residue, samples were subjected to gas chromatography. No putative Salmonella spp. colonies (with a black center) were isolated However, other potentially pathogenic bacteria suspected of Escherichia coli, Enterobacter sp., or Shigella sp. were isolated Cypermethrin concentrations (0.006-0.054 mg kg-1) were within the maximum residue limit. Knowing that some vegetables are eaten raw or slightly cooked, consumers are at risk of ingesting residual amounts of pesticides and are prone to bacterial infection. Hence, the food safety of fresh vegetables should be monitored from local farms to markets.

Determination of the Most Efficient Household Technique for the Reduction of Pesticide Residues from Raw Fish Muscles.

Substantial quantities of pesticides are routinely applied to enhance agricultural crop production. Pesticides used in this way continuously accumulate in the environment and in foods. Harvested crops contain pesticide residues at various concentrations, with potential harmful impacts on human health. Hence, it is of value to identify techniques for the effective decontamination of tainted foods. However, cleaning with water or household agents, e.g., acetic acid and sodium bicarbonate, are recognized treatments for the efficient degradation of pesticides from vegetables and fruits. There is an apparent void of information about the decontamination treatments for raw fishes using household agents that are affordable for all classes of consumers. Hence, the present study was performed to determine the most efficient household technique for reducing pesticide residue levels from precooked raw fish to ensure the utmost food safety. Fish muscles of four species of fishes, viz., Clarias gariepinus, Channa striatus, Anabas testudineus and Trichogaster trichopterus, were treated with six treatments: washing with running tap water (T1), dipping in normal water (T2), dipping in 2% salt solution (T3), dipping in 2% vinegar (T4), dipping in 0.1% sodium bicarbonate solution (T5) as well as dipping in 0.1% sodium bicarbonate solution + 2% vinegar + 2% salt solution + lemon juice (T6), as fish muscle is the major consumable portion of fish. The current study demonstrated that the removal percentage of lindane, heptachlor, aldrin, endosulfan, dieldrin, endrin, DDT, methoxychlor and cypermethrin residues against the treated household treatments, in downward order, were soaking in 0.1% sodium bicarbonate solution + 2% vinegar + 2% salt solution + lemon juice solution (T6) > soaking in 2% vinegar (T4) solution > soaking in 0.1% sodium bicarbonate (T5) solution > soaking in 2% salt (T3) solution > washing with running tap water (T1) > soaking in stable normal water (T2). The treatment of raw fish muscle samples by soaking them in 0.1% sodium bicarbonate solution + 2% vinegar + 2% salt solution + lemon juice was found to be the most efficient household treatment, performing significant reductions (%) in pesticide concentration: 72–80% (p < 0.05) in Channa striata, 71–79% (p < 0.05) in Clarias gariepinus, 74–80% (p < 0.05) in Anabas testudineus as well as 78–81% (p < 0.05) in Trichogaster trichopterus before cooking.

Dietary risk assessment of selected organophosphorus and pyrethoid pesticide residues in fresh harvested tomatoes at Makambako Town, Njombe region, Tanzania

ABSTRACT This study aimed to assess the levels of selected pesticides residues in harvested tomatoes and their associated dietary risks to consumers at Makambako Town in Njombe region, Tanzania. Forty-two fresh tomatoes were sampled among tomato farmers during harvesting season and extraction of analytes was done using QuEChERS method and analysed by Gas Chromatography-Mass Spectrometer. Residues of chlorpyrifos, profenofos, gamma cyhalothrin and cypermethrin were alternatingly detected in 78.51% of samples. The average concentrations of residues were 0.014, 0.056, 0.003 and 0.2 mg/kg for chlorpyrifos, profenofos, gamma cyhalothrin and cypermethrin and were all below their respective Codex MRLs. The highest concentration was 0.718 mg/kg for cypermethrin, above the Codex MRL of 0.2 mg/kg. The hazard indexes indicate no potential health hazards to the general population due to the lifetime consumption of fresh tomatoes from the study area. Periodic monitoring of residue levels of pesticides in vegetable fruits, including tomatoes, is recommended.

Evaluate toxicological residues of pesticide on Brassica oleracea before and after Dhavana by Vishaghna Dravya Albizzia Lebbek

Ayurveda is classified into 8 branches Agadtantra is one of important branch of Astanga ayurved which deals with study of poisons origin their properties harmful effects fatal doses their management prevention of poisoning method of detection and estimation of poison. Poisons may be from herbs, mineral or animal origin. In modern science parallel branch known as Toxicology. Today the scope of toxicology continues to grow rapidly and the subject is to profound importance to human and animal life too. Evaluation of residues of pesticides on Cauliflower (Brassica oleracea) before and after Dhavana by Vishaghna Dravya Shirish (Albizzia Lebbek). Cauliflower (Brassica oleracea) and Shirish panchanga (Albizzia Lebbek). Identification and authentication was done in department of Dravyaguna. The percentage of Cypermethrin residue was found to be decreased more by shirish kwatha(73.86% ) than hot water(67.33) and tap water(51.56%). The percentage of Chlorpyrifos residue was found to be decreased more by shirish kwatha(48.83%) than hot water(42.93%) and tap water(35.71%). The percentage of Imidaclopride residue was found to be decreased by tap water(86.54%) than that of hot water(72.44%) and shirish kwatha (78.84%).Dhavana with shirish kwatha was found more efficient method for reduction of pesticidal residue in cauliflower.

Risk assessment, development and validation of a GC-ECD-based method for the quantification of cypermethrin from green pea.

The present work describes the persistence, dissipation behaviour, half-life, risk assessment and novel gas chromatography method for the residue estimation of cypermethrin in green pea by spraying cypermethrin 10EC at 50 g a.i. ha-1 at fruiting stage followed by another application at a 10 day interval. The sample extraction and cleanup was followed bya modified quick, easy, cheap, effective, rugged, and safe method, and the residues of cypermethrin were determined using a validated gas chromatography method. The initial deposits were found to be 1.21 mg kg-1 following the application of insecticide at 50 g a.i. ha-1 . Cypermethrin residues declined to below the detection limit of 0.05 mg kg-1 after 15 days at the recommended dosage. The half-life of cypermethrin was 2.66 days at 50 g a.i. ha-1 . For risk assessment studies, the waiting period of 15 days is recommended as safe for consumption for the insecticide. The GC-ECD method was validated according to the SANTE guidelines by various analytical parameters including linearity, accuracy, detection and quantification limits. The developed method is simple, selective and repeatable, and can be used for the standardization of pesticides on fruits and vegetables.

Pesticide contamination of water used for urban market gardening in Bamako (Mali)

The use of natural and synthetic pesticides is increasingly common in developing countries, particularly in pest control efforts to improve crop yields. Misuse of these plant protection products can lead to a loss of efficacy on crops and the development of certain diseases. Among the most widely used insecticides in the world, pyrethroids are generally very fast acting against all insects but are also very toxic to the aquatic environment. In Mali, there are few studies on the risks of these phytosanitary products for market gardening on the health of rural populations and on the environment. It is in this context that we are conducting our research on phytosanitary products intended for various vegetable crops. The objective is to determine the level of pesticide contamination of water used for urban market gardening in Bamako, particularly by pyrethroids. In order to carry out these analyses, we collected water from wells, boreholes, marigots and the Niger River during the dry season and in winter. We chose a solid phase extraction (SPE) for the active substances present in the water. For their separation, we used an Ultra Performance Liquid Chromatography (UPLC) chromatograph, which allows a single separation for the active substances present in the water. The analytical results show the presence of cypermethrin residues. Market gardening uses a large quantity of synthetic pesticides, but there is a change in practice with the use of biopesticides, which would eventually reduce the risks for the environment and the health of the applicators.

Degradation of the insecticides fipronil and cypermethrin in green onions (Allium fistulosum) and mustard greens (Brassica juncea)

Pesticide dissipation on foods like vegetables, fruits, and cereals is one of the most concerning aspects in pesticide toxicology as it involves risks to human health and food safety. In light if this, a laboratory-scale study was conducted for two separate systems, green onions (Allium fistulosum) and mustard greens (Brassica juncea),in order to identify the dissipation of fipronil and cypermethrin, two commonly used insecticides, under a tropical climate. After the pesticide application, vegetable samples from these microcosms were collected each day for 7 days to measure fipronil and cypermethrin (n=3) residues. The analytical method was validated and showed repeatability and trueness. The decay equations fit well to first-order kinetics with a correlation coefficient of R2&gt;0.93 and p&lt;0.0005. The calculated half-life values of fipronil were 2.9 d for green onions and 3.2 d for mustard greens while those of cypermethrin were, respectively, 4.5 d and 3.2 d. To meet the maximum residue levels (MRL) of fipronil (0.02 mg/kg) and cypermethrin (0.7 mg/kg) on vegetables, the estimated pre-harvest intervals should be updated to 23 d and 7.5 d, respectively.