Overview of deltamethrin residues and toxic effects in the global environment.

Pyrethroids are synthetic organic insecticides. Deltamethrin, as one of the pyrethroids, has high insecticidal activity against pests and parasites and is less toxic to mammals, and is widely used in cities and urban areas worldwide. After entering the natural environment, deltamethrin circulates between solid, liquid and gas phases and enters organisms through the food chain, posing significant health risks. Increasing evidence has shown that deltamethrin has varying degrees of toxicity to a variety of organisms. This review summarized worldwide studies of deltamethrin residues in different media and found that deltamethrin is widely detected in a range of environments (including soil, water, sediment, and air) and organisms. In addition, the metabolism of deltamethrin, including metabolites and enzymes, was discussed. This review shed the mechanism of toxicity of deltamethrin and its metabolites, including neurotoxicity, immunotoxicity, endocrine disruption toxicity, reproductive toxicity, hepatorenal toxicity. This review is aim to provide reference for the ecological security and human health risk assessment of deltamethrin.

A field realistic model to assess the effects of pesticides residues and adulterants on honey bee gene expression.

While studies on the sublethal effects of chemical residues in beeswax on adult honey bees are increasing, the study protocols assessing the impacts on honey bee brood in realistic conditions still need to be investigated. Moreover, little is known about the residue's effect on gene expression in honey bee brood. This study reports the effects of chlorpyriphos-ethyl, acrinathrin and stearin worker pupae exposure through contaminated or adulterated beeswax on the gene expression of some key health indicators, using a novel in vivo realistic model. Larvae were reared in acrinathrin (12.5, 25, 10 and 100 ppb) and chlorpyriphos-ethyl (5, 10, 500 and 5000 ppb) contaminated or stearin adulterated beeswax (3, 4, 5, 6 and 9%) in newly formed colonies to reduce the influence of external factors. On day 11, mortality rates were assessed. Honey bee pupae were extracted from the comb after 19 days of rearing and were analysed for the gene expression profile of four genes involved in the immune response to pathogens and environmental stress factors (Imd, dorsal, domeless and defensin), and two genes involved in detoxifications mechanisms (CYP6AS14 and CYP9Q3). We found no linear relation between the increase in the pesticide concentrations and the brood mortality rates, unlike stearin where an increase in stearin percentage led to an exponential increase in brood mortality. The immune system of pupae raised in acrinathrin contaminated wax was triggered and the expression of CYP6AS14 was significantly upregulated (exposure to 12.5 and 25 ppb). Almost all expression levels of the tested immune and detoxification genes were down-regulated when pupae were exposed to chlorpyrifos-contaminated wax. The exposure to stearin triggered the immune system and detoxification system of the pupae. The identification of substance-specific response factors might ultimately serve to identify molecules that are safer for bees and the ecosystem's health.

Metabolism-based category formation for the prioritisation of genotoxicity hazard assessment for plant protection product residues (Part 4): α-Chloroacetamides.

In dietary risk assessment of plant protection products, residues of active ingredients and their metabolites need to be evaluated for their genotoxic potential. The European Food Safety Authority recommend a tiered approach focussing assessment and testing on classes of similar chemicals. To characterise similarity, in terms of metabolism, a metabolic similarity profiling scheme has been developed from an analysis of 69 α-chloroacetamide herbicides for which either Ames, chromosomal aberration or micronucleus test results are publicly available. A set of structural space alerts were defined, each linked to a key metabolic transformation present in the α-chloroacetamide metabolic space. The structural space alerts were combined with covalent chemistry profiling to develop categories suitable for chemical prioritisation via read-across. The method is a robust and reproducible approach to such read-across predictions, with the potential to reduce unnecessary testing. The key challenge in the approach was identified as being the need for metabolism data individual groups of plant protection products as the basis for the development of the structural space alerts.

Cytochrome P450 CYP736A12 is crucial for Trichoderma asperellum-induced alleviation of phoxim phytotoxicity and reduction of pesticide residue in tomato roots.

Trichoderma can enhance the metabolism of organophosphate pesticides in plants, but the mechanism is unclear. Here, we performed high-throughput transcriptome sequencing of roots upon Trichoderma asperellum (TM) inoculation and phoxim (P) application in tomato (Solanum lycopersicum L.). A total of 4059 differentially expressed genes (DEGs) were obtained, including 2110 up-regulated and 1949 down-regulated DEGs in P vs TM+P. COG and KOG analysis indicated that DEGs were mainly enriched in signal transduction mechanisms. We then focused on the pesticide detoxification pathway and screened out cytochrome P450 CYP736A12 as a putative gene for functional analysis. We suppressed the expression of CYP736A12 in tomato plants by virus-induced gene silencing and analyzed tissue-specific phoxim residues, oxidative stress markers, glutathione pool, GST activity and related gene expression. Silencing CYP736A12 significantly increased phoxim residue and induced oxidative stress in tomato plants, by attenuating the TM-induced increased activity of antioxidant and detoxification enzymes, redox homeostasis and transcripts of detoxification genes including CYP724B2, GSH1, GSH2, GR, GPX, GST1, GST2, GST3, and ABC. The study revealed a critical mechanism by which TM promotes the metabolism of phoxim in tomato roots, which can be useful for further understanding the Trichoderma-induced xenobiotic detoxification and improving food safety.

A screening-level human health risk assessment of dietary intake of pesticide residues in produce as compared to consumer guide recommendations.

Consumers are confronted with conflicting information regarding the safety of specific foods. For example, the Environmental Working Group (EWG) publishes an annual consumer guide in which they rank the pesticide contamination of 46 popular fruits and vegetables, which includes designating the 12 with the greatest pesticide contamination as the "Dirty Dozen," to help consumers reduce exposures to toxic pesticides. However, consumer guides like EWG's only incorporate some hazard assessment principles and do not reflect a dietary risk assessment. Therefore, the purpose of this study is to apply risk assessment techniques to EWG's Dirty Dozen list using a uniform screening-level approach to estimate pesticide exposures for U.S. consumers and to characterize the associated chronic human health risks. The most commonly detected pesticide and its representative residue concentrations were identified for each produce type on the 2022 Dirty Dozen list using the USDA Pesticide Data Program database. Estimates of mean dietary consumption in the U.S. were used to calculate dietary exposure to each pesticide-produce combination for adults and children. Pesticide-specific U.S. EPA dietary health-based guidance values (HBGVs) were then used as benchmarks to evaluate the chronic human health risk of consuming each produce type. Overall, the estimated daily exposure for each pesticide-produce combination was below the corresponding HBGV for all exposure scenarios. The current analysis demonstrates that excessive produce-specific pesticide exposure is unexpected as the amount of produce that would need to be consumed on a chronic basis, even among children, far exceeds typical dietary intake. Future research is necessary to assess acute dietary exposure scenarios and to consider cumulative risk.

Unlocking the interaction of organophosphorus pesticide residues with ecosystem: Toxicity and bioremediation.

Organophosphorus adulteration in the environment creates terrestrial and aquatic pollution. It causes acute and subacute toxicity in plants, humans, insects, and animals. Due to the excessive use of organophosphorus pesticides, there is a need to develop environmentally friendly, economical, and bio-based strategies. The microbiomes, that exist in the soil, can reduce the devastating effects of organophosphates. The use of cell-free enzymes and yeast is also an advanced method for the degradation of organophosphates. Plant-friendly bacterial strains, that exist in the soil, can help to degrade these contaminants by oxidation-reduction reactions, enzymatic breakdown, and adsorption. The bacterial strains mostly from the genus Bacillus, Pseudomonas, Acinetobacter, Agrobacterium, and Rhizobium have the ability to hydrolyze the bonds of organophosphate compounds like profenofos, quinalphos, malathion, methyl-parathion, and chlorpyrifos. The native bacterial strains also promote the growth abilities of plants and help in detoxification of organophosphate residues. This bioremediation technique is easy to use, relatively cost-effective, very efficient, and ensures the safety of the environment. This review covers the literature gap by describing the major effects of organophosphates on the ecosystem and their bioremediation by using native bacterial strains.

Pesticide residues in drinking water treatment plants and human health risk assessment: a case study from Northern Iran.

These days, the presence of pesticide residues in drinking water sources is a serious concern. In drinking water treatment plants (DWTPs), various methods have been proposed to remove pesticide residues. This study was designed with the objectives of monitoring the occurrence and seasonal variations of pesticides in the output of drinking water treatment plants in two Northern provinces of Iran, Gilan and Golestan, and identifying their human health risks. Seventeen pesticide residues from different chemical structures were determined by using a gas chromatograph-mass spectrometer (GC-MS). The results showed that only Alachlor, Diazinon, Fenitrothion, Malathion, and Chlorpyrifos were detected. The pesticide concentrations ranged from ND to 405.3 ng/L and were higher in the first half-year period. The total non-carcinogenic human health risks was in safe range for infants, children, and adults (HI < 1). The carcinogenic human health risks of Alachlor for infants, children, and adults were in the range of 4.3 × 10-7 to 1.3 × 10-6, 2.0 × 10-7 to 9.6 × 10-7, and 1.1 × 10-7 to 5.5 × 10-7, respectively. These values do not pose health risks for adults and children, but may present a possible cancer risk for infants in two DWTPs of Golestan. In conclusion, considering the possibility of exposure to these pesticides through other routes, simultaneously, it is suggested to carry out a study that examines the level of risk by considering all exposure routes. We also propose stricter regulations for the sale and use of pesticides in Iran.

Probabilistic risk assessment of endocrine disrupting pesticides in Iran.

The chronic dietary risk assessment for 34 pesticides suspected of acting as endocrine disrupters in Iran was assessed by comparing TMDI with the Acceptable Daily Intakes (ADI). Of 34 investigated endocrine-disrupting pesticides (EDPs), 6 had TMDI > ADI. In addition, potential non-carcinogenic and carcinogenic health risk assessments were evaluated using Monte Carlo simulation. HQ in wheat was 17.40 and 20.29 in adults and children, respectively. Due to dimethoate residue in wheat, HQ was 2.78, and for fenitrothion residue, 3.22. HI was 21.22 for adults and 24.76 for children in wheat, more than 1. Total Carcinogenic risk (TCR) due to EDPs residues was 6.40 × 10-5 in apples, in citrus fruits 5.97 × 10-5, 3.33 × 10-5 in cucumber, 5.30 × 10-5 in lettuce, in potato was 2.36 × 10-5, in rice was 1.61 × 10-5, 1.78 × 10-5 in tomato, and due to epoxiconazole residues in wheat was 3.18 × 10-5, more than acceptable limit 1.0 × 10-6. Therefore, consumers were at significant risk of carcinogenesis.Abbreviations: PCBs: polychlorinated biphenyls; BPA: Bisphenol A; ED: Endocrine Disrupting; EDCs: Endocrine Disrupting Chemicals; EDPs: Endocrine Disrupting Pesticides; ADI: Acceptable Daily Intake; TMDI: Theoretical Maximum Daily Intake; FAO: Food and Agriculture Organization; WHO: World Health Organization; MRL: Maximum Residue Limit; HQ: Hazard Quotient; HI: Hazard Index; CR: Cancer Risk; TCR: Total Cancer Risk; PPP: plant protection products.

Lethal and behavioural toxicity of differently aged insecticide residues on European earwigs (Forficula auricularia) in the laboratory and in the field.

Pesticide residues are an important topic in many environmental studies, but little is known about the effects of pesticide residues of different ages on beneficial arthropods. Therefore, in this study the activity of residues of three different ages of several commonly used insecticides on the behaviour and mortality of European earwigs was evaluated in the laboratory and the effect of the insecticides was verified in the field. All residues of the biorational SpinTor® (spinosad), Radiant SC (spinetoram), and the conventional Steward® (indoxacarb) showed significantly faster mortality progression compared to the control in the laboratory. All the Steward® residues caused a significant wave of erratic behaviour as the earwigs went through a deep and relatively long moribund stage and resurrected. We verified the effects of SpinTor® and Steward® on changes in earwig abundance and their behaviour in the orchard. Earwigs abundance was significantly lower 16 days after application of biorational SpinTor® and conventional Steward® which had a significantly more pronounced and longer lasting effect. The earwig population stabilised by day 53 after the insecticide applications. Field applications of insecticides had no effect on earwig behaviour and sex ratio. Our results show that older residues have a negative effect on European earwigs equal to that of fresh residues, although their degradation should occur. It is interesting to note that biorational insecticides may not be safer than chemical insecticides.

Concentration and non-dietary human health risk assessment of pesticide residues in soil of farms in Golestan province, Iran.

Detection of pesticide residues in soil samples was conducted using UHPLC-MS/MS. Non-dietary health risk assessment was conducted using calculate chronic daily intake (CDI) from ingestion, inhalation and dermal contact pathways and following non-carcinogenic and carcinogenic risks in the adults and adolescent. The rank order of pesticide in soil based on their concentration was malathion (0.082 mg kg-1)> cyproconazole (0.019 mg kg-1)> propargite (0.018 mg kg-1)> butachlor (0.016 mg kg-1) > chlorpyrifos (0.0067 mg kg-1)> diazinon (0.0014 mg kg-1)> imidacloprid (0.0007 mg kg-1). Hazard index (HI) values obtained of exposure to pesticides in soil in adults and adolescent were 0.0012 and 0.0035, respectively. Hence, exposed population are at the acceptable range of non-carcinogenic risk (HI < 1). Cancer risk (CR) values due to propargite in soil via ingestion pathway in adults and adolescent were 2.03E-09 and 2.08E-09, respectively; therefore, carcinogenic risk due to the exposure to pesticide contaminated soil was safe range (CR < 1E-06).

Current-use pesticides monitoring and ecological risk assessment in vegetable soils at the provincial scale.

Pesticides represent one of the largest intentional inputs of potentially hazardous compounds into agricultural soils. However, as an important vegetable producing country, surveys on pesticide residues in soils of vegetable production areas are scarce in China. This study presented the occurrence, spatial distribution, correlation between vegetable types and pesticides, and ecological risk evaluation of 94 current-use pesticides in 184 soil samples from vegetable production areas of Zhejiang province (China). The ecological risks of pesticides to soil biota were evaluated with toxicity exposure ratios (TERs) and risk quotient (RQ). The pesticide concentrations varied largely from below the limit of quantification to 20703.06 µg/kg (chlorpyrifos). The situation of pesticide residues in Jiaxing is more serious than in other cities. Soils in the vegetable areas are highly diverse in pesticide combinations. Eisenia fetida suffered exposure risk from multiple pesticides. The risk posed by chlorpyrifos, which exhibited the highest RQs at all scenarios, was worrisome. Only a few pesticides accounted for the overall risk of a city, while the other pesticides make little or zero contribution. This work will guide the appropriate use of pesticides and manage soil ecological risks, achieving green agricultural production.

Knowledge, attitude and practices of farmers and experts about the effects of pesticide residues on agricultural product users and ecosystems: A case of Fogera District, Ethiopia.

Pesticides are chemicals used to control different types of pests. Though pesticides played a role in improving the quantity and quality of production, they have been threatening ecosystems and posed effects on humans in different parts of the world. Unfortunately, there were no studies made about the effects of pesticide residues on ecosystems and consumers in the Fogera District of Amhara Region, Ethiopia. Hence, the main objective of this study was to understand the knowledge, attitude, and practices of respondents about the effects of pesticide residues on ecosystems and consumers. A cross-sectional survey complemented by focus group discussions and field observations was used to gather the required data for the study. The close-ended data were analyzed using descriptive statistics, logistic regressions, and independent t-test, and data from open-ended questions were grouped and summarized based on their similarities. The findings of the study confirmed that there was significant knowledge, attitude, and practices difference between farmers and consumers about the effects of pesticide residues on ecosystems and humans. Farmers used highly toxic pesticides to control pests and improve the glossiness of vegetables and khat. Though they didn't use the sprayed vegetables for their home consumption, some of the farmers deliberately supplied pesticide-sprayed vegetables without worrying about the negative effects of the pesticides on the consumers. There were also fishing practices from rivers after intoxicating the fish using the pesticide sprayed feed. This, in turn, might poison individuals who consume the fish. In general, pesticide application practices and consumption of pesticide-sprayed foodstuffs and surface water might pose serious health risks to ecosystems and humans. To minimize the negative effects of pesticides, rigorous awareness-raising on the effects and management of pesticides, enforcement of laws, delineation of the pesticide free buffer zone for waters, the establishment of a clear pesticide supply chain to the end users, ecosystem assessment and food safety monitoring schemes are highly required.

Global assessment of honeybee exposure to pesticides through guttation consumption: An indicator approach.

Guttation consumption is a potential pathway of pesticide residue exposure in honeybees. However, modeling tools for assessing honeybee exposure to pesticide residues in guttation drops are lacking. In this study, we propose an indicator-based approach for qualitatively or quantitatively analyzing the guttation-based exposure pathway, allowing us to conduct region-specific pesticide residue exposure assessments for honeybees. Exposure scores (the product of guttation production and residue level scores) were established to compare or rank honeybee exposure to pesticide residues via guttation intake across locations using three specified indicators (i.e., air temperature, relative humidity, and precipitation intensity). Warm, dry regions had high residue level scores (indicating high residue levels in guttation), whereas cold, wet regions had high guttation production scores (indicating high possibilities of guttation formation on leaf surfaces); their exposure scores were a combination of these two values. We evaluated and ranked honeybee exposure to imidacloprid residue across regions in Brazil, China, the United States, and selected European Union member states, revealing that pesticide application in many Brazilian federative units may raise honeybee risks due to high exposure scores. We also compared the guttation pathway to other common exposure pathways (nectar and pollen), suggesting that for some moderately lipophilic compounds, the guttation exposure pathway may not be ignored and should be further evaluated.

Pesticides in multigrains and risk assessment for Koreans by age group.

Using GC-MS/MS, 365 pesticides were analysed simultaneously in multigrains collected in the metropolitan area in 2018 and 2019. A risk assessment was performed for the detected pesticides. The limit of quantification, recovery and relative standard deviation for the pesticides ranged from 0.9-10.5 µg/kg, 70.3-89.3% and 3.0-10.3%, respectively. Among the 240 samples of multigrains, a total of 104 pesticides were detected, resulting in a detection rate of 32.9%. Out of these, 79 samples contained more than one pesticide. Risk assessment was conducted across all age groups, ranging from children to the elderly. The hazard quotient of phenothrin in glutinous rice was found to be 0.977, which was the highest in this study. However, the hazard index did not exceed 1 in any age group. These results indicated that the detected pesticides do not pose a serious public health concern. Nonetheless, regular monitoring is necessary to ascertain food safety.

Occurrence of pesticide residues in honey from apiaries with incidents of honeybee poisoning in East China and a corresponding risk assessment for honeybees and Chinese consumers.

We investigated the occurrence of 80 pesticide residues in 96 honey samples from apiaries with honeybee poisoning incidences by liquid chromatography-tandem mass spectrometry and subsequently conducted risk assessments of exposure for in-hive honeybees and Chinese consumers. Six pesticides were detected with residue concentrations ranging from 0.5 to 130.9 µg/kg. The mean concentrations of acetamiprid, dinotefuran, hexythiazox, propargite, semiamitraz, and carbendazim in positive samples were 7.9 ± 9.1, 5.9 ± 1.7, 3.0 ± 1.6, 44.2 ± 50.0, 9.0 ± 9.4, and 5.5 ± 4.1 µg/kg, respectively. Carbendazim, semiamitraz, and acetamiprid were the major contaminants in honey, with incidences of 99.0%, 93.8%, and 49.0%, respectively. The cooccurrence of pesticides (≥2 pesticides) was detected in 95.9% of the samples, with up to six residual pesticides found in one sample. The HQ (hazard quotient) values of the six pesticides to in-hive honeybees were from 4.7 × 10-8 to 0.021, less than 1, indicating their acceptable exposure risk to honeybees. In terms of the representative-case and worst-case scenarios, the sum of separate HQs of each pesticide yielding an HI (hazard index) ranged from 0.012 to 0.016 for in-hive worker honeybees and from 0.015 to 0.021 for in-hive larva honeybees, indicating an overall acceptable potential cumulative risk of multiple pesticides to in-hive honeybees. Both the %ARfD (acute reference dose) value (0.0001-0.075) and %ADI (acceptable daily intake) value (0.00002-0.0046) of risky pesticides were much less than 100, revealing acceptable risk exposure to risky pesticides via honey consumption for human health. Thus, our results showed that multipesticide residual honey from apiaries with honeybee poisoning incidents in East China was safe for humans and in-hive honeybees. PRACTICAL APPLICATION: This analytical approach will be used in detecting multiple pesticide residues in honey and risk assessment for dietary exposure to pesticide residues. It can support various surveillance programs about honey safety and in-hive honeybee health evaluation.

Pesticide residues in bee bread, propolis, beeswax and royal jelly - A review of the literature and dietary risk assessment.

Due to pollinator decline observed worldwide, many studies have been conducted on the pesticide residue content of apicultural products including bee bread, propolis, beeswax and royal jelly. These products are consumed for their nutraceutical properties, although, little information is available on the human health risk posed by pesticides present in them. In our research, studies dealing with the pesticide contamination of the above-mentioned hive products are reviewed. Dietary exposures were calculated based on the recommended daily intake values and concentration data reported by scientific studies. Potential acute and chronic health risk of consumers were evaluated by comparing the exposure values with health-based guidance values. Available data indicate that a wide range of pesticide residues, especially acaricides may accumulate in bee bread, propolis and beeswax, up to concentration levels of more thousand µg/kg. Based on our observations, tau-fluvalinate, coumaphos, chlorfenvinphos, chlorpyrifos and amitraz are commonly detected pesticide active substances in beehive products. Our estimates suggest that coumaphos and chlorfenvinphos can accumulate in beeswax to an extent that pose a potential health risk to the consumers of comb honey. However, it appears that pesticide residues do not transfer to royal jelly, presumably due to the filtering activity of nurse bees during secretion.

Pesticide residues in nectar and pollen of melon crops: Risk to pollinators and effects of a specific pesticide mixture on Bombus terrestris (Hymenoptera: Apidae) micro-colonies.

Residues detected in pollen collected by honey bees are often used to estimate pesticide exposure in ecotoxicological studies. However, for a more accurate assessment of pesticides effect on foraging pollinators, residues found directly on flowers are a more realistic exposure approximation. We conducted a multi-residue analysis of pesticides on pollen and nectar of melon flowers collected from five fields. The cumulative chronic oral exposure Risk Index (RI) was calculated for Apis mellifera, Bombus terrestris and Osmia bicornis to multiple pesticides. However, this index could underestimate the risk since sublethal or synergistic effects are not considered. Therefore, a mixture containing three of the most frequently detected pesticides in our study was tested for synergistic impact on B. terrestris micro-colonies through a chronic oral toxicity test. According to the result, pollen and nectar samples contained numerous pesticide residues, including nine insecticides, nine fungicides, and one herbicide. Eleven of those were not applied by farmers during the crop season, revealing that melon agroecosystems may be pesticide contaminated environments. The primary contributor to the chronic RI was imidacloprid and O. bircornis is at greatest risk for lethality resulting from chronic oral exposure at these sites. In the bumblebee micro-colony bioassay, dietary exposure to acetamiprid, chlorpyrifos and oxamyl at residue level concentration, showed no effects on worker mortality, drone production or drone size and no synergies were detected when pesticide mixtures were evaluated. In conclusion, our findings have significant implications for improving pesticide risk assessment schemes to guarantee pollinator conservation. In particular, bee pesticide risk assessment should not be limited to acute exposure effects to isolated active ingredients in honey bees. Instead, risk assessments should consider the long-term pesticide exposure effects in both pollen and nectar on a range of bees that reflect the diversity of natural ecosystems and the synergistic potential among pesticide formulations.

Distribution and risk assessment of pesticide residues in sediment samples from river Ganga, India.

Indiscriminate use of pesticides leads to their entry in to the bottom sediments, where they are absorbed in the sediment's particle and thus, may become the consistent source of aquatic pollution. The present work was carried out to evaluate pesticide residues in the sediment samples and associated human health risk of commonly used pesticides along the basin of river Ganga. Total of 16 pesticides were analyzed along three stretches of river Ganga. The concentration of pesticides in the upper stretch ranged from ND to 0.103 µg/kg, in the middle stretch ND to 0.112 µg/kg, and in the lower stretch ND to 0.105 µg/kg. Strong positive correlation was found between total organic carbon and total pesticide residues in sediment samples. Carcinogenic and non-carcinogenic values were estimated below the threshold limit suggesting no associated risk. Risks associated with the inhalation route of exposure were found to be higher than the dermal and ingestion routes. Children were found at higher risk at each site from multiple routes of exposure than adult population groups. Toxic unit values were found to be below the threshold value suggesting no risk associated with exposure of pesticides from sediments. However, long term effects on ecological quality due to consistent pesticide exposure must not be ignored. Therefore, the present study focuses on concrete efforts like lowering the irrational used of pesticides, tapping of agricultural and domestic drains, advice to farmers for appropriate use of pesticide doses, to reduce the threat of pesticide pollution in the river system and possible human health risk.

Honey as a bioindicator of environmental organochlorine insecticides contamination / Mel como bioindicador de contaminação ambiental de inseticidas organoclorados

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

Resumo O mel é uma matriz adequada para a avaliação de contaminantes ambientais, incluindo inseticidas organoclorados. O presente estudo foi conduzido para avaliar resíduos de 15 inseticidas organoclorados em amostras de mel de origem unifloral e multifloral de Dir, Paquistão. Amostras de mel (5 g cada) foram extraídas com solventes orgânicos de grau GC e, em seguida, submetidas ao evaporador rotativo até a secura. Os extratos foram então misturados com n-hexano (5 ml) e purificados por cromatografia em coluna. Os extratos purificados (1μl cada) foram processados através de cromatógrafo gasoso acoplado a detector de captura de elétrons (GC-ECD) para identificação e quantificação dos inseticidas. Dos 15 inseticidas testados, 46,7% foram detectados enquanto 53,3% não foram detectados nas amostras de mel. O heptacloro foi o inseticida mais prevalente com um nível médio de 0,0018 mg / kg detectado em 80% das amostras, seguido por β-HCH com um nível médio de 0,0016 mg / kg detectado em 71,4% das amostras de mel. Amostras de mel da parede de Acacia modesta foram 100% positivos para heptacloro com um nível médio de 0,0048 mg / kg seguido por β-HCH com um nível médio de 0,003 mg / kg e frequência de 83,3%. Níveis mínimos dos inseticidas testados foram detectados no mel unifloral de Ziziphus jujuba da usina. Metoxicloro, Endosulfan, Endrin e metabólitos do DDT não foram detectados nas amostras de mel estudadas. Alguns dos inseticidas testados são proibidos no Paquistão, mas ainda são detectados em amostras de mel, indicando seu uso na área de estudo. Os níveis detectados de todos os inseticidas estavam abaixo dos Níveis Máximos de Resíduos (MRLs) e seguros para os consumidores. No entanto, os níveis detectados podem causar mortalidade na fauna de insetos. O uso de inseticidas proibidos é um dos principais fatores responsáveis pelo declínio das populações de importantes insetos polinizadores, incluindo as abelhas.

Residual levels and dietary exposure risk assessment of banned pesticides in fruits and vegetables from Chinese market based on long-term nontargeted screening by HPLC-Q-TOF/MS.

The negative impact of banned pesticides is of special importance for their high toxicity. In this study, nationwide screening of banned pesticides in 37462 fruit and vegetable samples was carried out from 2012 to 2018 using a self-developed HPLC-Q-TOF/MS technique. The dietary exposure risks associated with the banned pesticides were assessed. The results showed that 66.62 % of the samples were detected at least one pesticide. Among the pesticide-positive samples, a total of 18 banned pesticides were detected in 1798 samples for 1896 times. The risk assessment revealed that 11.71 % of the positive detections exceeded the safety limits and posed an unacceptable risk, while 37.29 % of the positive detections posed acceptable risks. According to the screening and assessment results, two national maps were presented to show the total detection ratios of the banned pesticides and the unacceptable risks of dietary exposure. It should be noted that omethoate had higher residual concentration, unacceptable risk frequency and unacceptable risk proportion. This is the first nationwide comprehensive report on screening and risk assessment banned pesticides.