Chlorpyrifos Methyl Research Articles

Glacier foreland insect uptake synthetic compounds: an emerging environmental concern.

Pesticides, synthetic fragrances and polycyclic aromatic hydrocarbons contaminated two glacier-fed streams (Amola, Mandrone) and one spring (Grostè) in the Italian Alps. Ten compounds (chlorpyrifos (CPY), chlorpyrifos-methyl (CPY-m), galaxolide (HHCB), tonalide (AHTN), fluorene (Flu), phenanthrene (Phen), anthracene (Ant), fluoranthene (Fl), pyrene (Pyr), benzo[a]anthracene (BaA)) accumulated in aquatic larvae of chironomids (Diamesa steinboecki, D. latitarsis, D. bertrami, D. tonsa, D. zernyi, Pseudokiefferiella parva, Orthocladiinae) and tipulids. Their tissue concentrations (detected by gas chromatography coupled with mass spectrometry) ranged from 1.1 ± 0.1ng/g d.w. (= dry weight) (CPY-m in D. tonsa from Amola) to 68.0 ± 9.1ng/g d.w. (Pyr in D. steinboecki from Mandrone). HHCB, AHTN, and CPY, with one exception, were accumulated by all aquatic insects. Six compounds (CPY, CPY-m, HHCB, AHTN, Fl, Pyr) also contaminated carabids (Nebria germarii, N. castanea, N. jockischii) predating adults of merolimnic insects. Their tissue concentrations ranged from 1.1 ± 0.3ng/g d.w. (CPY-m in N. germarii from Mandrone) to 84.6 ± 0.3ng/g d.w. (HHCB in N. castanea from Grostè). HHCB and AHTN were accumulated by all Nebria species. Intersite and interspecies differences were observed, which might be attributed to different environmental contamination levels. There was a stronger similarity between species from the same site than among the same species from different sites, suggesting that uptake is not species specific. At all sites, the concentration of xenobiotics was higher in larvae than in water and comparable or higher in carabids than in larvae from the same site, suggesting trophic transfer by emerging aquatic insects to their riparian predators.

Application of biological early warning systems in wastewater treatment plants: Introducing a promising approach to monitor changing wastewater composition

Wastewater treatment plants (WWTPs) are a major source of micropollutants to surface waters. Currently, their chemical or biological monitoring is realized by using grab or composite samples, which provides only snapshots of the current wastewater composition. Especially in WWTPs with industrial input, the wastewater composition can be highly variable and a continuous assessment would be advantageous, but very labor and cost intensive. A promising concept are automated real-time biological early warning systems (BEWS), where living organisms are constantly exposed to the water and an alarm is triggered if the organism's responses exceed a harmful threshold of acute toxicity. Currently, BEWS are established for drinking water and surface water but are seldom applied to monitor wastewater. This study demonstrates that a battery of BEWS using algae (Chlorella vulgaris in the Algae Toximeter, bbe Moldaenke), water flea (Daphnia magna in the DaphTox II, bbe Moldaenke) and gammarids (Gammarus pulex in the Sensaguard, REMONDIS Aqua) can be adapted for wastewater surveillance. For continuous low-maintenance operation, a back-washable membrane filtration system is indispensable for adequate preparation of treated wastewater. Only minor deviations in the reaction of the organisms towards treated and filtered wastewater compared to surface waters were detected. After spiking treated wastewater with two concentrations of the model compounds diuron, chlorpyrifos methyl, and sertraline, the organisms in the different BEWS showed clear responses depending on the respective compound, concentration and mode of action. Immediate effects on photosynthetic activity of algae were detected for diuron exposure, and strong behavioral changes in water flea and gammarids after exposure to chlorpyrifos methyl or sertraline were observed, which triggered automated alarms. Different types of data analysis were applied to extract more information out of the specific behavioral traits, than only provided by the vendors algorithms. To investigate, whether behavioral movement changes can be linked to impact other endpoints, the effects on feeding activity of G. pulex were evaluated and results indicated significant differences between the exposures. Overall, these findings provide an important basis indicating that BEWS have the potential to act as alarm systems for pollution events in the wastewater sector.

Highly-oxidizing Au@MnO2−X nanozymes mediated homogeneous electrochemical detection of organophosphorus independent of dissolved oxygen

Traditional oxidase-like (OXD) nanozymes rely primarily on O2-mediated superoxide anion (O2·−) process for catalytic oxidation and organophosphorus (Ops) detection. While during the actual detection process, the concentration of O2 is inconstant that can be easily changed with the external environment, distorting detection results. Herein, highly-oxidizing Au@MnO2−X nanozymes with core-shell nanostructure are designed which trigger substantial electron transfer from inner Au core to outer ultrathin MnO2−X layer. According to experimental and theoretical calculations, the core-shell nanostructure and ultrathin MnO2−X of Au@MnO2−X result in the large surface defects, high oxygen vacancies and MnIII ratios. The specially structured Au@MnO2−X nanozymes are therefore highly-oxidizing and the catalytic oxidation can be completed merely through electrons transferring instead of the O2-mediated O2·− process. Based on this, an oxygen independent and ultrasensitive nanozyme-based sensor is established using homogeneous electrochemistry (HEC), its Ops is detected at a LOD of 0.039 ng mL−1. Combined with the UV–vis spectrum of 3,3′,5,5′-tetramethylbenzidine (TMB), the linear discriminant analysis of five Ops i.e., Ethion, Omethoate, Diazinon, Chlorpyrifos methyl and Dipterex has achieved superior discrimination results. Therefore, HEC based on strong oxidizing nanozymes provide a new avenue for the development of high-performance electrochemical sensors and demonstrate potential applicability to pesticide residue determination in real samples.

Evaluation of three organophosphorus insecticides alone and in combination with inert dusts for the control of Trogoderma granarium Everts (Coleoptera: Dermestidae)

Management of Trogoderma granarium with insecticides alone is difficult due to its high tolerance to commonly used insecticides. In the present study, three organophosphorus insecticides (OPs), chlorpyrifos-methyl (CH), pirimiphos-methyl (PI) and malathion (MA) were evaluated alone or in binary blends with diatomaceous earth (DE), kaolin (KA) and zeolite (ZE) against T. granarium on stored wheat. The following concentrations were used: CH (2.5 and 5 ppm), PI (5 and 10 ppm), MA (4 and 8 ppm) and inert dusts (IDs) (500 and 1000 ppm). The number of dead larvae was counted 1, 2 and 3 weeks after exposure. Progeny (F1 and F2) was recorded 30 and 80 days after exposure, respectively. The wheat grain damage was measured at the end of experiments (80 days). The results revealed that the mortality of khapra beetle larvae was higher in all binary mixture treatments of OPs and IDs than individual ones. The mixtures of CH with IDs caused complete larval mortality at application rate (5 ppm). The binary mixtures of PI or MA with IDs induced strong mortality of T. granarium larvae (>82%). Furthermore, the results indicate that the combination of CH and inert dusts or PI with ZE at the highest rate completely suppressed F1 and F2 progeny after 80 days of treatment. The lowest number of F1 and F2 progeny was recorded in wheat treated with MA (8.0 ppm) + DE (1000 ppm) with 1.0 and 1.6 adults/50g, respectively. The mixtures of OPs and IDs at the highest tested rate protected wheat grains against damage caused by insect for 80 days. The findings of the present study indicate that the binary mixtures of OPs, especially CH and IDs are highly effective for the control of khapra beetle and could be implemented in the management of this destructive invasive insect.

Pesticide Residues and Unauthorized Dyes as Adulteration Markers in Chilli Pepper and Tomato.

To assess the contamination of processed chilli pepper and tomatoes, a report over the past four decades since the establishment of the Rapid Alert System for Food and Feed (RASFF) was retrieved and analysed. Out of the 887 notification reports assessed for eligibility, 446 were found regarding chilli pepper and tomato contamination. This study identified India as the country of origin with the highest number of reported cases relating to chilli pepper contamination. Italy and Türkiye were the countries with the highest number of reported cases regarding the exportation of adulterated tomatoes to other countries according to the RASFF report. Unauthorized dyes such as Sudan I, III, IV, orange II, rhodamine B, and para red were reported to have been detected in either chilli pepper or tomato in the supply chain. Almost all unauthorized dyes in this study were found to be more than the range (0.5 to 1 mg/kg) of the detection limit of Sudan dye and other related dyes using analytical methods set by the European Union. Unapproved pesticides by the European Union (EU) found in this study were acetamiprid, chlorothalonil, chlorpyrifos, dimethoate, methomyl, monocrotophos, omethoate, oxamyl, and thiophanate methyl. The present study indicates the persistence of chilli pepper and tomato contamination with harmful dyes and pesticide residues despite the ban on the use of certain chemicals in the food chain.

Developmental toxicity of chlorpyrifos-methyl and its primary metabolite, 3,5,6-trichloro-2-pyridinol to early life stages of zebrafish (Danio rerio)

Chlorpyrifos-methyl (CPM) is one of the thiophosphate insecticides, and it is mainly metabolized to 3,5,6-trichloro-2-pyridinol (TCP) in the environment. As CPM is a strongly toxic and TCP is persistent in the environment, CPM and TCP need to be evaluate their toxicities using animal model organisms. With this regard, CPM and TCP were treated on zebrafish (Danio rerio) embryos and LC50 values were determined as over 2000 μg/L and 612.5 μg/L, respectively. For the hatchability, CPM did not exhibit any interference, while TCP showed weak inhibition. In the CPM-treated embryos, pericardial edema and bleeding were observed at 48 hpf, but recovered afterwards. The pericardial edema and yolk sac edema were observed in TCP-treated zebrafish embryos at the concentration of 500 μg/L after 72 hpf. TCP induced abnormal heart development and the heartbeat was dramatically decreased in Tg(cmlc2:EGFP) embryos at the level of 500 μg/L. The expression level of heart development-related genes such as gata, myl7, and cacna1c was significantly decreased in the TCP 500 μg/L-treated embryos at the 96 hpf. Taken together, TCP appears to be more toxic than the parent compound towards the zebrafish embryos. It is highly requested that TCP needs to be monitored with a strong public concern because it affects presumably heart development in early-stage aquatic vertebrates.

The Simultaneous Determination of Chlorpyrifos-Ethyl and -Methyl with a New Format of Fluorescence-Based Immunochromatographic Assay.

The improper and excessive use in agriculture of chlorpyrifos-methyl (CPSM) and chlorpyrifos-ethyl (CPSE) may affect the health of human beings. Herein, a fluorescence-based immunochromatographic assay (FICA) was developed for the simultaneous determination of CPSM and CPSE. A monoclonal antibody (mAb) with equal recognition of CPSM and CPSE was generated by the careful designing of haptens and screening of hybridoma cells. Instead of labeling fluorescence with mAb, the probe was labeled with goat-anti-mouse IgG (GAM-IgG) and pre-incubated with mAb in the sample. The complex could compete with CPS by coating antigen in the test line. The new format of FICA used goat-anti-rabbit IgG (GAR-IgG) conjugated with rabbit IgG labeled with fluorescence microspheres as an independent quality control line (C line). The novel strategy significantly reduced nonspecific reactions and increased assay sensitivity. Under the optimal conditions, the proposed FICA showed a linear range of 0.015-64 mg/L and limit of detection (LOD) of 0.015 mg/L for both CPSE and CPSM. The average recoveries of CPS from spiked food samples by FICA were 82.0-110.0%. The accuracy was similar to the gas chromatography-tandem mass spectrometry (GC-MS/MS) results. The developed FICA was an ideal on-site tool for rapid screening of CPS residues in foods.

Development and validation of multiresidue method for organophosphorus pesticides in lanolin using gas chromatography-tandem mass spectrometry.

Lanolin, also known as wool wax, is derived from sheep and has diverse applications in food, cosmetic, textile and lubricant industries. Owing to its direct contact with human, there is a need of studying pesticide residues as contaminants in lanolin. The present study describes a single novel hyphenated gas chromatography-tandem mass spectrometry (GC-MS/MS) technique for the quantification of 14 organophosphorus (OP) pesticides (tecnazene, propetamphos, diazinon, dichlofenthion, chlorpyrifos methyl, fenchlorphos, malathion, chlorpyrifos, pirimiphos ethyl, bromophos ethyl, tetrachlorvinphos, ethion, phosalone, and coumaphos) in lanolin using electrospray ionization (EI) with multiple reaction monitoring (MRM) acquisition mode. The method is simple in terms of sample preparation steps based on matrix solid-phase dispersion (MSPD). The method was found to be linear over the analytical range of 0.05-2.0μg/g, with acceptable coefficient of determination (r2 ≥0.99) for all the 14 pesticides. The limit of detection (LOD) and limit of quantification (LOQ) of the method were found to be less than 0.05 and 0.1μg/g, respectively, for all the 14 OP pesticide residues. The precision and accuracy of the method were found to be within the acceptable limits, that is, recoveries in the range of 83.5%-104.1% with less than 12.5% of relative standard deviation for all the pesticides. The multiresidue method for estimating pesticide residues employing GC-MS/MS technique will be useful for OP pesticide levels in large number of lanolin samples.

Assessment of genotoxic effects of organophosphate and carbamate pesticides by comet assay

Background and Aims: Pesticide poisoning is the most widespread occupational hazard for agricultural workers in the developing world, due to the extensive presence of pesticides in the environment. The aim of this study was to investigate the cytotoxicity and DNA damaging effects of organophosphosphate and carbamate pesticides. Methods: In the present study, the cytotoxicity of chlorpyrifos methyl, azinphos ethyl, [(O-Ethyl O-(p-nitrophenyl) pheriylphosphonothioate] (EPN), aldicarb sulfone, and ethiofencarb were assessed by the trypan blue dye exclusion method. An alkaline comet assay was performed to assess the genotoxic effects of applied pesticides in human peripheral blood lymphocytes. Results: We demonstrated the cytotoxic effect of EPN following 30 and 120 min exposure at 100 µg/mL concentration. Although chlorpyrifos-methyl and azinphos ethyl seem to be safer concerning cytotoxicity compared to other pesticides, significantly higher DNA damage levels were determined after exposure of these pesticides for 120 min at 100 µg/mL concentration by in vitro comet assay. The potential DNA-damaging effects of these pesticides were sorted from high to low, as chlorpyrifos-methyl, aldicarb sulfone, EPN, and azinphos ethyl after 30 min of exposure, and were sorted as chlorpyrifosmethyl, azinphos ethyl, aldicarb sulfone, and EPN after 120 min of exposure. Our results revealed that these pesticides tend to increase DNA damage in a dose- and time-dependent manner. Conclusion: The genotoxic effects of these widely used pesticides may cause prominent and serious health risks for human populations; hence, the DNA-damaging potential of pesticides can lead to genotoxic risk and adverse health effects like cancer.

Isolation, characterization and growth assessment of biodegrading chlorpyrifos-methyl Bacillus species isolated from Algerian soil

Chlorpyrifos-methyl (CM) is a broad-spectrum organophosphate insecticide, which is widely used in pest control. In this research, the isolation, and biochemical and molecular identification of bacterial strains obtained from three soils located in northeastern Algeria were carried out, as well as the evaluation of their ability to grow in the presence of CM. Out of 48 bacterial isolates between Gram-negative and Gram-positive identified, several were able to grow on mineral agar with at least 25 mg·l–1 of CM. Four bacteria showed the best growth capacity, were identified as Bacillus sp. H1-80, Brevibacterium frigoritolerans strain WJB99 and two Bacillus sp. strains GL5. The strains were tested for their ability to grow on liquid media with CM as the sole energy and carbon source. In general, these strains showed slow but significant growth visualized by the 600 nm turbidity control, suggesting that they could be used for bioremediation applications of CM polluted soils.

Control of Sitophilus granarius and Sitophilus oryzae on stored wheat using low-rate combinations of natural zeolite with three insecticides

The insecticidal potential of three insecticides (chlorpyrifos-methyl (CH), deltamethrin (DE), spinosad (SP)), zeolite (ZE) and their low-rate combinations was tested against Sitophilus granarius (L.) and Sitophilus oryzae (L.) adults. The application rates were: CH at 0.1, 0.5 and 1.0 mg/kg, DE at 0.2, 0.5, 1.0 and 2.0 mg/kg, SP at 0.1, 0.25, 0.5 and 1.0 mg/kg, and ZE at 100 and 500 mg/kg. Individual treatments with CH, DE or SP at 1.0 mg/kg induced 100, 83.9 and 76.2% mortality of S. granarius, and 95.5, 69.3 and 88.2% mortality of S. oryzae after 21 days, respectively. Treatment with ZE alone at 500 mg/kg caused 43.5 and 50.3% mortality of S. granarius and S. oryzae, respectively, after 21 days. The combined treatments of insecticides and ZE showed higher adult mortality than treatments with each insecticide or ZE alone. Combined treatments of CH (0.5 mg/kg) + ZE (100 mg/kg), CH (0.1 mg/kg) + ZE (500 mg/kg), CH (0.5 mg/kg) + ZE (500 mg/kg) and SP (1.0 mg/kg) + ZE (500 mg/kg) induced 100% adult mortality of both insects after 21 days. In addition, a mixture of DE (1.0 mg/kg) + ZE (500 mg/kg) caused 100% mortality of S. oryzae after 21 days. Progeny of both insects decreased significantly in all treatments compared by untreated wheat grain. The mixtures, CH (0.5 mg/kg) + ZE (500 mg/kg), DE (1.0 mg/kg) + ZE (500 mg/kg, SP (1.0 mg/kg) + ZE (100 mg/kg) and SP (1.0 mg/kg) + ZE (500 mg/kg), induced remarkable progeny reduction (≈100%) and complete protection of wheat grain (weight loss = 0.0%) against damage caused by insects for 90 days. Our results indicate that the combination of insecticides with ZE at low rates is a promising approach for the control of S. granarius and S. oryzae on stored wheat.

Combinations of insecticides with carbon dioxide for the management of Sitophilus oryzae (Linnaeus 1763) on stored wheat: An approach to reduce the application rates of insecticides

Efficacy of insecticides chlorpyrifos-methyl (CH), deltamethrin (DE) and spinosad (SP) was evaluated alone and in binary combinations with carbon dioxide (CA) against Sitophilus oryzae (L.). Mortality of S. oryzae adults was recorded after 3, 7 and 14 days, and progeny production and wheat weight loss were assessed after 90 days for all treatments. In individual treatments, the mortality of S. oryzae adults was 69.5, 79.8, 50.7 and 61.4% after 14 days of exposure to the highest concentration of CA (30%), CH (0.5 mg/kg), DE (1.0 mg/kg) and SP (0.5 mg/kg), respectively. Mortality of S. oryzae adults was higher in combined treatments at all tested rates than individual treatments. Mortality of adults of 100% was obtained in combined treatments of CH (0.5 mg/kg) + CA (30%) after 3 days and DE (1.0 mg/kg) + CA (30%) after 14 days of exposure. Combinations of SP + CA were more effective than CH + CA and DE + CA as 100.0% mortality was achieved in combined treatments of SP at 0.25 mg/kg with CA at 20 and 30%, and SP at 0.5 mg/kg with CA at 20 and 30% after 3 days of exposure. Progeny production of S. oryzae was decreased significantly in all treatments compared with untreated wheat grains after 90 days of exposure. High rates induced progeny reduction of 100% and complete protection of wheat grains against damage caused by S. oryzae after 90 days. Moreover, germination percentages of wheat seeds treated with CH at 0.5 mg/kg, DE at 1.0 mg/kg, CA at 30% and CH at 0.5 mg/kg + CA at 30% were 90.6, 86.7, 86.7 and 90.0, respectively. Our results indicate that the combination of insecticides with CA appears promising as an approach for the control of S. oryzae.

Study of the Photocatalytic Degradation of Highly Abundant Pesticides in Agricultural Soils.

Organic pesticides are major sources of soil pollution in agricultural lands. Most of these pesticides are persistent and tend to bio accumulate in humans upon consumption of contaminated plants. In this study, we investigate different natural soil samples that were collected from agricultural lands. The samples revealed the presence of 18 pesticides that belong to four different groups including organochlorines (OCP), organophosphorus (OPP), carbamates (Carb), and pyrethroids (Pyrth). The photocatalytic degradation of the five most abundant pesticides was studied in the presence and absence of 1% TiO2 or ZnO photocatalysts under UV irradiation at a wavelength of 306 nm. The five abundant pesticides were Atrazine (OCP), Chlorpyrifos methyl (OPP), Dimethoate (OPP), Heptachlor (OCP), and Methomyl (Carb). The results showed that photolysis of all pesticides was complete under UV radiation for irradiation times between 64–100 h. However, both photocatalysts enhanced photocatalytic degradation of the pesticides in comparison with photolysis. The pesticides were photocatalytically degraded completely within 20–24 h of irradiation. The TiO2 photocatalyst showed higher activity compared to ZnO. The organochlorine heptachlor, which is very toxic and persistent, was completely degraded within 30 h using TiO2 photocatalyst for the first time in soil. The mechanism of photocatalytic degradation of the pesticides was explained and the effects of different factors on the degradation process in the soil were discussed.

Cascade reaction system integrating nanozymes for colorimetric discrimination of organophosphorus pesticides

Organophosphorus pesticides (OPs) are widely used in pest control. The residual OPs can cause pollution to the environment and harm to the human body. Although OPs can inhibit the activity of acetylcholinesterase (AChE) and lead to neurological diseases, it also provides enlightenment for the development of a simple and sensitive method for the detection of OPs. Herein, we report a colorimetric sensor array using nanozymes (Fe-N-C nanozymes and Cu-N-C nanozymes) combined with natural enzymes to discriminate eight OPs (Iprobenfos (Ipr), Diazinon (Dia), Crotoxyphos (Cro), Bromophos ethyl (Bro), Dipterex (Dip), Chlorpyrifos methyl (Chl), Ethion (Eth), and Omethoate (Ome)) through a cascade reaction system. Surprisingly, eight OPs were successfully identified in tap water at 1 ng mL−1.

Longitudinal Assessment of Chlorpyrifos Exposure in Farmers and Residents of an Italian Alpine Region

The aim of this study was to obtain a longitudinal evaluation of the exposure to chlorpyrifos (CP) and chlorpyrifos-methyl (CPM) in agricultural workers in South Tyrol and in a residential group living in the same area. CP and CPM are widely used pesticides in agriculture. Biological monitoring of CP and CPM exposure in humans can be achieved by analyzing urinary levels of 3,5,6-trichloro-2-pyridinol (TCPy). TCPy a metabolite of CP and CPM which is produced by a two-step metabolic transformation. Between May 14th, 2014 and March 16th, 2015 we conducted a longitudinal study on 28 farmers actively working in spray pesticide treatment and 43 non-farmers living in the same agricultural area of South Tyrol (Italy). Urine samples were collected at two time points: during the pesticide treatment period and in a temporally distant season that should guarantee metabolite clearance. We developed and validated a liquid chromatography-tandem mass spectrometry (LC–MS/MS) method for the determination of urinary TCPy levels. During the treatment season, both farmers and residents showed higher TCPy levels (median = 6.8 and 6.73 ug/g creatinine, respectively) than during the non-treatment season (median = 2.54 and 3.22 ug/g creatinine, respectively), suggesting a similar effect of the pesticide spraying on both groups. However, the observed TCPy levels resulted in a daily CP and CPM intake well below the limits recommended by FAO/WHO. During the non-treatment season, non-farmers showed higher TCPy levels values than farmers, suggesting the existence of TCPy of other unmeasured sources of exposure not considered in this study. This suggests that, for a comprehensive evaluation of the risks associated with TCPy exposure, additional sources should be identified in addition to CP and CPM pesticides.

Evaluation of work place pesticide concentration and health complaints among women workers in tea plantation, Southern India.

Women contribute fifty percent of the total work force in tea plantation sector. The continuous use of chemical pesticides in plantation may increase the risk of exposure and can cause detrimental health effects. To assess the health status of women worker exposed to pesticides in tea plantation and to evaluate the pesticide levels in work environment. A cross sectional study was performed (n = 204) to assess the health complaints among exposed women workers (n = 116) and non-exposed women (n = 88) using a predesigned questionnaire. Work environmental air samples collected using PUF sampler and personal samplers were analyzed forvarious pesticides. Musculoskeletal disorder, skin color changes, allergies and asthma were the most commonly reported health complaints. Notably, only 16% of the women used personal protective equipment (PPE) while 68% reported to have experienced tea plantation work up to 6 month of their pregnancy period. Chlorpyrifos methyl (8.3%), carbendazim (6.7%), thiamethoxam (4.2%), ethion (4.2%) and thiophanate methyl (2.1%) were detected in work place air samples. This study is the first to characterize pesticide levels in work place of women workers in India. Women are continuously exposed to pesticides through their work and environmental exposure. Preventive measures are essential to mitigate the adverse health effects of pesticides among women workers.

Pesticide residues and health risk appraisal of tomato cultivated in greenhouse from the Mediterranean region of Turkey.

This research aims at assessing the health risks associated with pesticide residues in greenhouse grown tomato production in the Mediterranean Region of Turkey. A multiresidue method based on modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) was used for sample preparation that is applied for pesticide detection from extraction of tomato samples in the methodology generated by The Association of Official Analytical Chemists (AOAC) Official Method. The restrain of the quantification varied from 0.002 to 0.009 mg kg-1. The validated data exposed both adequate recoveries, repeatability and reproducibility, including accomplished all other requirements of the European DG SANTE/12682/2019 Guideline. This study divulges that tomatoes cultivated in greenhouse demonstrate 61.5% of samples with one or various pesticide residues. The maximum permitted residue level of above the EU DG Guideline was in 12.2% of the samples. The main determined pesticide residues on the tomatoes cultivated in greenhouse were identified as chlorpyrifos methyl, cyfluthrin, deltamethrin, and acetamiprid. Chlorpyrifos methyl (9.5%), cyfluthrin (6.6%), deltamethrin (5.5%), and acetamiprid (3.2%) were recognized as the most conducing residues to the hazard index (HI). The HI was 9.5% for adults and 11.02% for children (3 to <10 years). The major contributor of the HI was chlorpyrifos in both.

Reduced insecticide susceptibility of the wheat aphid Sitobion miscanthi after infection by the secondary bacterial symbiont Hamiltonella defensa.

Bacterial symbionts in insects, especially aphids, have a major influence on host adaptation. We previously showed that infection with the secondary symbiont Hamiltonella defensa increases the fitness of the wheat aphid Sitobion miscanthi, yielding increases in fitness parameters such as adult weight and offspring number. However, whether H. defensa affects the sensitivity of host aphids to insecticides remains unknown. We tested the effects of H. defensa on host aphid susceptibility to the insecticides chlorpyrifos methyl, imidacloprid, cyantraniliprole and acetamiprid. Our results showed that compared with Hamiltonella-free aphid clones, Hamiltonella-infected aphid clones exhibited lower sensitivity to most of the tested insecticides at low concentrations. Quantitative polymerase chain reaction showed that the density of H. defensa in the infected clones was slightly decreased at 24 h but then sharply increased until the late stage after treatment with the different insecticides. H. defensa in the host aphids was detected by fluorescence in situ hybridization and was localized to the aphid hindgut. Levels of the detoxification enzymes acetylcholinesterase, glutathione transferase and carboxylesterase were significantly higher in Hamiltonella-infected clones than in Hamiltonella-free clones. The findings indicated that infection with H. defensa reduced aphid susceptibility to the investigated insecticides at low concentrations, potentially by increasing detoxification enzyme activity in the host. Therefore, symbiont-mediated insecticide resistance should be taken into account when performing resistance-monitoring studies. Studies of symbiont-mediated insecticide resistance may enhance our understanding of the emergence of insecticide resistance in agricultural systems. © 2020 Society of Chemical Industry.

Understanding farmers’ safety behavior regarding pesticide use in Morocco

Abstract Unsafe pesticide use is a significant concern in rural areas, resulting in serious threats to farmer and environmental health. This problem can be especially severe in developing countries, including Morocco. However, few studies have explored the factors influencing farmers’ safety behavior regarding pesticide use in this country. Hence, we conducted a cross-sectional survey of 232 arboricultural farmers in 12 counties of Morocco's Saiss Plain to assess farmers’ pesticide safety behavior. Farmers’ characteristics, knowledge of pesticides, perceived risk, health consequences, subjective norms, and safety behavior data were collected and analyzed using a structural equation model (SEM). The majority of farmers have long term experience with pesticide use, but they followed poor safety practices, including insufficient use of personal protective equipment during pesticide handling. As a result, farmers showed a high incidence of health problems related to pesticide use (e.g., skin irritation and headaches). Unsafe pesticide handling was mostly attributable to farmers’ low education levels and insufficient training. Consequently, farmers applied high amounts of pesticides to increase production quantities (an average of 12.02 kg/ha per growing season). Although banned in the country, considerable use of organochlorines (i.e., endosulfan) and organophosphorus (i.e., chlorpyrifos ethyl and chlorpyrifos methyl) were reported. Adherence to safety behaviors while handling pesticides significantly improved with high levels of pesticide knowledge (standardized path coefficient, SPC = 0.31) and the perceived severity of the associated health risks (SPC = 0.27). Conversely, uncertainty about the risks of pesticide use was associated with a lower likelihood of adopting safety measures (SPC = 0.24). Improved knowledge of safe pesticide handling and training courses on the risks posed by pesticide exposure to human and environmental health are urgently needed to improve farmers’ safety behavior in Morocco.

Toxicological Effects of five Insecticides on Cabbage Aphid, Brevicoryne brassicae (L.) (Homoptera: Aphididae) and its Parasitoid Aphelinus sp. (Hymenoptera:Aphelinidae)

Cabbage aphid, Brevicoryne brassicae (L.) is an important agricultural insect pest that attacks many vegetable crops all over the world. Herein, the study was conducted to evaluate the efficacy of five insecticides, acetameprid 20% SP (neonicotinoid), abamactin 1.8% EC (avermectin), indoxicarb 15% EC (oxadiazine), chlorpyrifos methyl 50%EC (organophosphate) and lambda cyhalothrin 5% EC (pyrethroid) against cabbage aphids Brevicoryne brassicae (L.) and its parasitoid Aphelinus sp. under laboratory conditions. Mortality percentages for both cabbage aphid and parasitoid were determined after 24, 48 and 72-h after treatment. Result revealed that acetamiprid was the greatest toxic insecticide against cabbage aphid followed by abamectin and indoxacarb after 24 and 48-h of treatment. Otherwise, lambda cyhalothrin followed by chlorpyrifos methyl was the lowest toxicity on cabbage aphid after 24 and 48-h from treatment. In contrast, toxicological results for parasitoid suggested that acetamiprid had less toxicity followed by abamectin and indoxacarb after 24 and 48-h of treatment. whereas, lambda cyhalothrin followed by chlorpyrifos methyl demonstrated great toxicity on the parasitoid after 24 and 48-h of treatment. In addition, safety factor for each treatment was determined, and results revealed that greater safety factor was recorded for acetamiprid, abamectin and indoxacarb than chlorpyrifos methyl and lambda cyhalothrin. Thus, these results suggest that acetamiprid can be included in the Integrated Pest Management (IPM) Program against cabbage aphid with safe side and minimum harmful effect on its parasitoid.