Pesticide residues in honey and their potential reproductive toxicity

Seaweeds as a major source of dietary microplastics exposure in East Asia

Microplastics (MPs) occurrence in marine ecosystems is well known, but their accumulation in seaweeds and subsequent human exposure remain understudied. This research quantifies MPs presence in two commonly consumed seaweeds, kelp (Saccharina japonica) and nori (Pyropia yezoensis), in East Asia, revealing widespread contamination dominated by microfibers (<500 μm). Based on dietary patterns, human uptake through seaweed consumption was estimated and quantified. Notably, Chinese people consume an estimated 17,034 MPs/person/year through seaweed consumption, representing 13.1% of their total annual MPs intake. This seaweeds-derived exposure surpasses all other dietary sources, contributing up to 45.5% of overall MPs intake. The highest intake was in South Korea, followed by North Korea, China, and Japan. This research identifies seaweeds as a major, previously overlooked route of dietary MPs exposure. These findings are crucial for comprehensive risk assessments of seaweed consumption and the development of mitigation strategies, particularly for populations in East Asian countries.

Cytotoxic and genotoxic effects of a pendimethalin-based herbicide in Apis mellifera

Public concern about the effects of pesticides on non-target organisms has increased in the recent years. Nevertheless, there is a limited number of studies that address the actual toxic effects of herbicides on insects. This study investigated the side effects of herbicides on non-target organisms inhabiting agroecosystems and performing essential ecological and economic functions such as crop pollination. We analysed morphological alterations in the gut, Malpighian tubules and circulating haemocytes of Apis mellifera workers as markers of exposure effects. A commercial formulation of a pendimethalin-based herbicide (PND) was administered orally under laboratory conditions at a realistic concentration admitted in the field (330gL-1 of active ingredient., 4 L ha-1 for cereal and vegetable crops). The worker bees were exposed to a single application of PND for a period of one week, to simulate the exposure that can occur when foraging bees accidentally drink drops of contaminated water upon treatments. Histopathological analyses of the midgut, ileum and Malpighian tubules showed alterations over time (from 24 to 72 h after the beginning of exposure) such as loss of epithelial organisation, cellular vacuolisation and altered pyknotic nuclei as well as disruption of the peritrophic membrane over time. Semiquantitative analyses of the midgut showed a significant increase in the organ injury index 24 and 72 h after the initial exposure in PND-exposed bees compared to control bees. In addition, a change in positivity to Gram staining was observed in the midgut histological sections. A recovery of cytotoxic effects was observed one week after the initial exposure, which was favoured by the periodic renewal of the intestinal epithelium and the herbicide dissipation time. Cytochemical staining with Giemsa of haemocytes from PND-treated workers over 24 and 72 h showed significant nuclear alterations such as lobed or polymorphic nuclei and micronuclei compared to bees in the control group. These results show that the dose of PND used to protect crops from weeds can lead to significant cytotoxic and genotoxic effects in non-target organisms such as honey bees. In croplands, the sublethal effects on cell morphology can impair vital physiological processes such as nutrition, osmoregulation, and resistance to pathogens, contributing to the decline in biodiversity and abundance of species that play a prominent ecological role, such as pollinators.

Design, synthesis, and evaluation of novel arecoline-linked amino acid derivatives for insecticidal and antifungal activities

A series of arecoline derivatives with amino acid moieties were designed and synthesised using an acylamide condensation strategy, taking arecoline as the foundational structure. The insecticidal efficacy of these compounds against Aphis craccivora and Tetranychus cinnabarinus was evaluated. Notably, derivatives 3h and 3i demonstrated superior insecticidal activity compared with arecoline. Additionally, 3h and 3i showed good fungicidal effectiveness against two types of plant fungi. Moreover, molecular docking analyses suggested that 3h and 3i could affect the nervous systems of A. craccivora and T. cinnabarinus by binding to neuronal nicotinic acetylcholine receptors. These findings suggest that compounds 3h and 3i represent promising leads for further development in insecticide and fungicide research.

A proof-of-concept study on the versatility of liquid chromatography coupled to high-resolution mass spectrometry to screen for various contaminants and highlight markers of floral and geographical origin for different honeys

The high-resolution mass spectrometry is a powerful analytical tool for improving food safety and authenticity, but still underused in official control laboratories. The present work is a proof-of-concept study overviewing how liquid-chromatography coupled to high-resolution mass spectrometry could be used simultaneously for large-scale screening of contaminants and differentiation of honey samples. Within this study, the samples were extracted using all-in-one QuEChERS-based protocol that allowed for analysis of various anthropogenic contaminants and endogenous compounds. First, targeted-analysis of 52 honey samples led to unequivocal identification of 23 chemicals, including neonicotinoids, triazole fungicides and synergist. Then, suspect-screening using MSDial software allowed for tentative identification of 30 chemicals including plasticizers, flame-retardants and additives. Suspect-screening also made it possible to highlight tentative markers of chestnut honey (deoxyvasicinone, 2-quinolone, indoleacrylic acid and kynurenic acid) and citrus honey (caffeine, 2-oxindole and indole-3-carbinol). Lastly, non-targeted analysis enabled to separate honeys by their type, floral and geographical origins.

Perchlorate in honey from China: Levels, pollution characteristics and health risk assessment

The release and accumulation of perchlorate into the environment have raised concerns about safety to food, however, the dietary risk of perchlorate in honey have not yet received attention. Herein, we investigated the pollution characteristics and assessed the human health risks of perchlorate in honey from China. A total of 151 honey samples collected from 20 provinces of China were analyzed, and overall detection frequencies was 95.4 %. The levels of perchlorate ranged from below limit of quantitation to 612 μg/kg, with a mean value of 34.5 μg/kg. Lychee honey samples had the highest mean perchlorate concentration (163 μg/kg). The mean concentration of perchlorate in the honey samples produced in South China was significantly higher than that in honey from Southwest China, East China and North China (P < 0.05). The health risk assessment showed that mean hazard quotient (HQ) values of different honey for children (ranged from 0.0108 to 0.400) and adults (ranged from 0.0123 to 0.453) were less than 1. This result indicated that mean pollution levels of perchlorate in various honey were unlikely to pose health risk. However, perchlorate concentrations in two lychee honey samples had associated HQ values were >1, suggesting potential health risks. This work not only offers valuable information for honey consumer, but also important reference for comparison of honey samples in the future. ENVIRONMENTAL IMPLICATION: Perchlorate contamination has become a hot environmental issue in connection with human health due to its potential thyroid toxicity and widespread occurrence in environment and foods. Honey not only was widely beloved by consumers worldwide but also considered a potential indicator of environmental pollution. Here, a national investigation and risk assessment of perchlorate levels in different types of honey from China was conducted. The results describe the perchlorate contamination were extensive in honey samples, mean levels of perchlorate in various honey were unlikely to cause health risks. However, significantly high level of contamination in lychee honey should be of concern.

Efficient degradation of imidacloprid by surface discharge cold plasma: Mechanism of interaction between ROS and molecular structure and evaluation of residual toxicity

Incorrect use of neonicotinoid pesticides poses a serious threat to human and pollinator health, as these substances are commonly present in bee products and even drinking water. To combat this threat, the study developed a new method of degrading the pesticide imidacloprid using surface discharge cold plasma oxidation technology. The study showed that this method achieved a very high efficiency of imidacloprid degradation of 91.4%. The main reactive oxygen species (H2O2, O3, ·OH, O2-, 1O2) effectively participated in the decomposition reaction of imidacloprid. Reactive oxygen species were more sensitive to the structure of the nitroimine group. Density functional theory (DFT) further explored the sites of reactive oxygen species attack on imidacloprid and revealed the process of energy change of attacking imidacloprid. In addition, a degradation pathway for imidacloprid was proposed, mainly involving reactive oxygen species chemisorption, a ring-opening intermediate, and complete cleavage of the nitroimine group structure. Model predictions indicated that acute oral and developmental toxicity were significantly reduced after cold plasma treatment, as confirmed by insect experiments. Animal experiments have shown that plasma treatment reduces imidacloprid damage to mice hippocampal tissue structure and inhibits the reduction of brain-derived neurotrophic factor content, thus revealing the detoxification mechanism of the body.

The toxicity assessment of phosmet on development, reproduction, and gene expression in Daphnia magna

The use of pesticides to control pests, weeds, and diseases or to regulate plant growth is indispensable in agricultural production. However, the excessive use of these chemicals has led to significant concern about their potential negative impacts on health and the environment. Phosmet is one such pesticide that is commonly used on plants and animals against cold moth, aphids, mites, suckers, and fruit flies. Here, we investigated the effects of phosmet on a model organism, Daphnia magna using acute and chronic toxicity endpoints such as lethality, mobility, genotoxicity, reproduction, and gene expression. We performed survival experiments in six-well plates at seven different concentrations (0.01, 0.1, 1, 10, 25, 50, 100 μM) as well as the control in three replicates. We observed statistically significant mortality rates at 25 µM and above upon 24 h of exposure, and at 1 µM and above following 48 h of exposure. Genotoxicity analysis, reproduction assay and qPCR analysis were carried out at concentrations of 0.01 and 0.1 μM phosmet as these concentrations did not show any lethality. Comet assay showed that exposure to phosmet resulted in significant DNA damage in the cells. Interestingly, 0.1 μM phosmet produced more offspring per adult compared to the control group indicating a hormetic response. Gene expression profiles demonstrated several genes involved in different physiological pathways, including oxidative stress, detoxification, immune system, hypoxia and iron homeostasis. Taken together, our results indicate that phosmet has negative effects on Daphnia magna in a dose- and time-dependent manner and could also induce lethal and physiological toxicities to other aquatic organisms.

Seasonal screening of pesticide residues in beehive products collected from different districts in Egypt

Pesticides are of immense importance in agriculture, but they might contaminate bees' products. In this study, samples of honey, pollen, and beeswax were collected, seasonally, from apiaries in Toshka (Aswan), El-Noubariya (El-Beheira), and Ismailia (Ismailia) cities in Egypt. The pesticide residues were analyzed using the GC-MS after being extracted and cleaned using the QuEChERS method. Results showed that samples from El-Noubariya had great content of residues followed by Ismailia, and finally Toshka. Samples collected during fall and winter had the highest pesticide residue contents. Specifically, the phenylconazole fungicide group was repeatedly detected in all the examined samples along with organophosphate insecticides. Beeswax samples had the greatest amounts of pesticide residues followed by pollen and then honey samples. Chlorpyrifos (0.07-39.16 ng/g) and profenofos (1.94-17.00 ng/g) were detected in honey samples and their products. Pyriproxyfen (57.12 ng/g) and chlorpyrifos-methyl (39.16 ng/g) were detected in great amounts in beeswax samples from Ismailia and El-Noubariya, respectively. Yet, according to health hazard and quotient studies, the amounts of pesticides detected in honey do not pose any health threats to humans.

Application of magnetic dispersive solid phase extraction combined with solidification of floating organic droplet-based dispersive liquid-liquid microextraction and GC-MS in the extraction and determination of polycyclic aromatic hydrocarbons in honey

A magnetic dispersive solid phase extraction method combined with solidification of floating organic droplet-based dispersive liquid-liquid microextraction has been validated for the extraction of polycyclic aromatic hydrocarbons from honey samples. For this purpose, a carbonised cellulose-ferromagnetic nanocomposite was used as a sorbent through the magnetic dispersive solid phase extraction. For preparation of the sorbent, first, carbonised cellulose nanoparticles were created by treating cellulose filter paper with concentrated solution of sulfuric acid. Then, the prepared nanoparticles were loaded onto Fe3O4 nanoparticles through coprecipitation. In the extraction process, first, a few mg of the sorbent was added to the diluted honey solution and dispersed in it using vortex agitation. The particles were then separated and the adsorbed analytes were eluted with an organic solvent. The eluent was taken and after mixing with a water-immiscible extraction solvent was used in the following solidification of floating organic droplet-based dispersive liquid-liquid microextraction procedure. By performing the extraction process under the obtained optimum conditions, low limits of detection (0.08-0.17 ng g-1) and quantification (0.27-0.57 ng g-1), satisfactory precision (relative standard deviations ≤ 5.0%), and wide linear range (0.57-500 ng g-1) with great coefficients of determination (r2≥ 0.9986) were obtained.

Plants in the rearing of arthropod predators and parasitoids: benefits, constraints, and alternatives

This review explores the roles of plants in rearing systems for arthropod biological control agents, addressing benefits and drawbacks. The utilization of plant materials in mass rearing processes for predators and parasitoids serves various purposes. Natural rearing systems require plants for cultivating hosts or prey. Whereas these rearing systems can be economically viable, they also have important practical limitations. Alternative rearing strategies make use of plant components as sources of moisture or nutrients, and as living or oviposition substrates. Plant-derived foods, such as honey and pollen, can be used as stand-alone foods for the rearing of several omnivorous parasitoids and predators. Certain omnivorous predators show enhanced life table parameters when suboptimal food is supplemented with plant materials. However, the integration of plants into rearing systems introduces complexities that challenge their efficiency, as plant defenses and contaminants can impact natural enemy fitness. Therefore, alternatives to plant foods or substrates in the rearing environment are discussed.

In vivo-in vitro correlations (IVIVC) for the assessment of pyrethroid bioavailability in honey

Bioaccessibility/bioavailability is an important factor in assessing the potential human health risk via oral exposure. However, methods for accurately predicting the bioaccessibility/bioavailability of pesticide residues are still limited, preventing accurate measurements of actual exposure to pesticide residues. In this study, pyrethroid bioavailability in honey were analysed using a mouse bioassay and bioaccessibility via in vitro methods with Tenax extraction. The results demonstrated that the combined liver plus kidney data served as an appropriate biomarker to estimate the relative bioavailability. Notably, significant in vivo-in vitro correlations (IVIVC) were observed between bioavailability and bioaccessibility (R2 = 0.7898-0.9793). Estimation of the bioavailability of honey from different nectar plants using derived IVIVC confirmed that different contents and physicochemical properties might affect its bioavailability. The findings provide insight into assessing human exposure to pesticides based on bioavailability and can decrease the uncertainty about the assessment of the risk of dietary exposure to pesticides.

Glutathione conjugation and protein modification resulting from metabolic activation of pesticide metalaxyl in vitro and in vivo

Metalaxyl (MTL), a germicidal agent, is widely used in agriculture. Due to the biological amplification effect, MTL entering the ecological environment would result in a threat to human health through the food chain. MTL is reportedly accumulated in liver. The objectives of the study included investigating the metabolic activation of MTL in liver and defining the mechanisms participating in the hepatotoxicity of MTL. The corresponding glutathione (GSH), N-acetylcysteine (NAC) conjugate, and cysteine conjugates were observed in liver microsomes, prepared from liver tissues of mice, containing MTL and GSH, NAC or cysteine. These conjugates were also detected in urine and bile of rats receiving MTL. Apparently, MTL was biotransformed to a quinone imine intermediate dose-dependently attacking the thiols and cysteine residues of protein. The bioactivation of MTL required cytochrome P450 enzymes, and CYP3A dominated the bio-activation of MTL.

Fungicides and insecticides can alter the microbial community on the cuticle of honey bees

Honey bees are crucial for our ecosystems as pollinators, but the intensive use of plant protection products (PPPs) in agriculture poses a risk for them. PPPs do not only affect target organisms but also affect non-targets, such as the honey bee Apis mellifera and their microbiome. This study is the first of its kind, aiming to characterize the effect of PPPs on the microbiome of the cuticle of honey bees. We chose PPPs, which have frequently been detected in bee bread, and studied their effects on the cuticular microbial community and function of the bees. The effects of the fungicide Difcor® (difenoconazole), the insecticide Steward® (indoxacarb), the combination of both (mix A) and the fungicide Cantus® Gold (boscalid and dimoxystrobin), the insecticide Mospilan® (acetamiprid), and the combination of both (mix B) were tested. Bacterial 16S rRNA gene and fungal transcribed spacer region gene-based amplicon sequencing and quantification of gene copy numbers were carried out after nucleic acid extraction from the cuticle of honey bees. The treatment with Steward® significantly affected fungal community composition and function. The fungal gene copy numbers were lower on the cuticle of bees treated with Difcor®, Steward®, and PPP mix A in comparison with the controls. However, bacterial and fungal gene copy numbers were increased in bees treated with Cantus® Gold, Mospilan®, or PPP mix B compared to the controls. The bacterial cuticular community composition of bees treated with Cantus® Gold, Mospilan®, and PPP mix B differed significantly from the control. In addition, Mospilan® on its own significantly changed the bacterial functional community composition. Cantus® Gold significantly affected fungal gene copy numbers, community, and functional composition. Our results demonstrate that PPPs show adverse effects on the cuticular microbiome of honey bees and suggest that PPP mixtures can cause stronger effects on the cuticular community than a PPP alone. The cuticular community composition was more diverse after the PPP mix treatments. This may have far-reaching consequences for the health of honey bees.

Exposure to pesticide residues in honey and its potential cancer risk assessment

Honey is the most recognized natural food by-product derived from flower nectar and the upper aero-digestive tract of the honeybees. Significance of honey for its medicinal importance are well-documented in the world's oldest medical literatures. However, the current urbanization, environmental contaminations and changes in agricultural, as well as apiculture practices has led to various types of contaminations in honey. Among all, pesticide contamination has become one of the major issues worldwide. This review focuses on the recent updates concerning pesticides occurrence in honey, as well as how the repeated use and long-term exposure to honey contaminated with pesticide residues could affect the human physiological functions, possibly leading to the development of various cancers. Our findings suggests that uncontrolled use of pesticides in farming and apiculture practices leads to the occurrence of pesticides residues in honey. Therefore, regular consumption of such honey will pose a serious threat to human health, since most of the pesticides has been reported as potential carcinogens. This review will draw the attention of honey consumers, scientific communities, apiculture farmers, as well as governing bodies to strictly monitor the pesticide usage in floriculture, agriculture as well as other related practices.

The directed acyclic graph helped identify confounders in the association between coronary heart disease and pesticide exposure among greenhouse vegetable farmers

To explore the causal pathways associated with coronary heart disease (CHD) and pesticide exposure using a directed acyclic graph (DAG) analysis and to investigate the potential benefits of DAG by comparing it with logistic regression. This cross-sectional study enrolled 1368 participants from April 2015 to May 2017. Trained research investigators interviewed farmers using a self-administered questionnaire. Logistic regression and DAG models were used to identify the associations between CHD and chronic pesticide exposure. A total of 150 (11.0%) of the 1368 participants are characterized as having CHD. High pesticide exposure (odds ratio = 2.852, 95% confidence intervals: 1.951-4.171) is associated with CHD when compare with low pesticide exposure by both DAG and logistic analyses. After adjusting for the additional potential influence of factors identified by the DAG analysis, there is no significant association, such as the results in logistic regression: ethnicity, education level, settlement time, and mixed pesticide status. Specifically, age, meal frequency, and consumption of fresh fruit, according to the DAG analysis, are independent factors for CHD. High pesticide exposure is a risk factor for CHD as indicated by both DAG and logistic regression analyses. DAG can be a preferable improvement over traditional regression methods to identify sources of bias and causal inference in observational studies, especially for complex research questions.

Research progress on pesticide residue detection based on microfluidic technology

The problem of pesticide residue contamination has attracted widespread attention and poses a risk to human health. The current traditional pesticide residue detection methods have difficulty meeting rapid and diverse field screening requirements. Microfluidic technology integrates functions from sample preparation to detection, showing great potential for quick and accurate high-throughput detection of pesticide residues. This paper reviews the latest research progress on microfluidic technology for pesticide residue detection. First, the commonly used microfluidic materials are summarized, including silicon, glass, paper, polydimethylsiloxane, and polymethyl methacrylate. We evaluated their advantages and disadvantages in pesticide residue detection applications. Second, the current pesticide residue detection technology based on microfluidics and its application to real samples are summarized. Finally, we discuss this technology's present challenges and future research directions. This study is expected to provide a reference for the future development of microfluidic technology for pesticide residue detection.

Effects of acephate and glyphosate-based agrochemicals on the survival and flight of Plebeia lucii Moure, 2004 (Apidae: Meliponini)

The conservation of terrestrial ecosystems depends largely on the preservation of pollinators, mainly bees. Stingless bees are among the main pollinators of native plants and crops in tropical regions, where they can be exposed to agrochemicals while foraging on contaminated flowers. In the present study, we investigated the effects on stingless bees of both a commonly used insecticide and herbicide in Brazil. Plebeia lucii Moure, 2004 (Apidae: Meliponini) foragers were orally chronically exposed to food contaminated with different concentrations of commercial formulations of the insecticide acephate or the herbicide glyphosate. Bee mortality increased with increasing agrochemical concentrations. Depending on its concentration, the acephate-based formulation reduced the lifespan and impaired the flight ability of bees. The glyphosate-based formulation was toxic only under unrealistic concentrations. Our results demonstrate that realistic concentrations of acephate-based insecticides harm the survival and alter the mobility of stingless bees. The ingestion of glyphosate-based herbicides was safe for forager bees under realistic concentrations.

Photochemical behavior and photo-induced toxicity of chiral pesticides and their chiral monomers in aqueous environment

The photochemical behaviors of chiral pollutants in aqueous solutions are rarely studied using chiral monomers, which may hamper their precise risk assessment and lead to suspicious conclusions. In this study, we systematically investigated the phototransformation behavior and toxicity evolution of two widely used chiral pesticides (triadimefon (TF) and triadimenol (TN)) at enantiomer and diastereomer levels, and proposed a calculation method of total photolysis rate constants of chiral mixture. Results show that TF and TN could be photodegraded faster in pure water than in natural waters, and the observed photolysis rate constants (k_obs) of TN with two chiral centers exhibit enantioselectivity, i.e., k_obs(TN-RS) = k_obs(TN-SR) > k_obs(TN-RR) = k_obs(TN-SS). The photolysis of TF and TN mainly occurs through their excited singlet and triplet states, respectively. Their photodegradation pathways mainly include dechlorination and elimination of triazole ring. TF could also undergo ether bond cleavage. It is also found that, both TF and TN exhibit photo-induced toxicity to V. fischeri, due to the generation of more toxic products than parent compounds. Furthermore, TN exhibits enantioselective photo-induced toxicity after 240-min irradiation, which could be ascribed to the formation of chiral products. These results could benefit the understanding of enantioselective environmental behavior of chiral pollutants.

Optimisation and implementation of QuEChERS-based sample preparation for identification and semi-quantification of 694 targeted contaminants in honey, jam, jelly, and syrup by UHPLC-Q/ToF high-resolution mass spectrometry

A screening and semi-quantitative method was developed for the analysis of 694 various contaminants in honey, jam, jelly and syrup samples by ultrahigh-performance liquid chromatography and quadrupole time-of-flight mass spectrometry. Sample preparation, which was optimised using split factorial design, was based on acetate-buffered version of QuEChERS, followed by a clean-up step and a concentration step to enhance sensitivity of analytes. The method was validated according to SANTE/11312/2021 guidelines. The screening detection and limits of identification were established as being less than or equal to 0.05 mg.kg^-1 for 89% and 74% of the contaminants, respectively. The validated screening method was applied to 50 concentrated sugary products. Overall, 46% of the samples were positive to pesticide residues. Most of the positive samples (78%) contained mixtures of pesticide residues. Three time-and-cost saving convenient strategies suitable for high-throughput analysis were proposed for the targeted semi-quantification of the previously contaminants identified in samples.

Enhanced Lateral Flow Immunoassay with Double Competition and Two Kinds of Nanoparticles Conjugates for Control of Insecticide Imidacloprid in Honey

Finding optimal conditions for competitive lateral flow immunoassay is a controversial task. The content of specific antibodies labeled by nanoparticles should be simultaneously high to reach intense signals and low to register an influence on the signals for minimal concentrations of the target analyte. We propose to use two kinds of complexes of gold nanoparticles in the assay, with antigen-protein conjugates and with specific antibodies. The first complex interacts both with immobilized antibodies in the test zone and with antibodies on the surface of the second complex. In this assay, the coloration is enhanced by the binding of two-colored preparations in the test zone, whereas the antigen in the sample inhibits both the binding of the first conjugate with the immobilized antibodies and with the second conjugate. This approach is realized for the detection of insecticide imidacloprid (IMD), an important toxic contaminant connected with the recent global death of bees. The proposed technique expands the working range of the assay, that is, in accordance with its theoretical analysis. The reliable change of coloration intensity is achieved for a 2.3-times-lower concentration of the analyte. The limit of IMD detection is 0.13 ng/mL for tested solutions and 1.2 µg/kg for initial honey samples. The combination of two conjugates doubles the coloration in the absence of the analyte. The developed lateral flow immunoassay is applicable for five-fold-diluted honey samples without extraction, does not require additional stages (all reagents are pre-applied to the test strip), and is implemented in 10 min.

A combination of the frequent fungicides boscalid and dimoxystrobin with the neonicotinoid acetamiprid in field-realistic concentrations does not affect sucrose responsiveness and learning behavior of honeybees

The increasing loss of pollinators over the last decades has become more and more evident. Intensive use of plant protection products is one key factor contributing to this decline. Especially the mixture of different plant protection products can pose an increased risk for pollinators as synergistic effects may occur. In this study we investigated the effect of the fungicide Cantus® Gold (boscalid/dimoxystrobin), the neonicotinoid insecticide Mospilan® (acetamiprid) and their mixture on honeybees. Since both plant protection products are frequently applied sequentially to the same plants (e.g. oilseed rape), their combination is a realistic scenario for honeybees. We investigated the mortality, the sucrose responsiveness and the differential olfactory learning performance of honeybees under controlled conditions in the laboratory to reduce environmental noise. Intact sucrose responsiveness and learning performance are of pivotal importance for the survival of individual honeybees as well as for the functioning of the entire colony. Treatment with two sublethal and field relevant concentrations of each plant protection product did not lead to any significant effects on these behaviors but affected the mortality rate. However, our study cannot exclude possible negative sublethal effects of these substances in higher concentrations. In addition, the honeybee seems to be quite robust when it comes to effects of plant protection products, while wild bees might be more sensitive.

Wide-Scope Multi-residue analysis of pesticides in beef by gas chromatography coupled with quadrupole Orbitrap mass spectrometry

Increasing pesticide contamination in foods of animal origin has made the wide-scope multi-residue analysis of pesticides an international concern. By using 191 pesticides, this study investigates a sensitive and reliable method for multi-residue analysis of pesticides in beef to determine the extent of the application of this method. The QuEChERS method was employed to extract and purify the pesticides as C18 was utilized as the absorbents. Then, the purified pesticides were analysed using gas chromatography - quadrupole orbitrap mass spectrometry (GC-Q-Orbitrap-MS). The validation test results revealed that this method was satisfactorily sensitive since its screening detection limit (SDL) ranged from 0.2 to 100 µg∙kg^-1. The recovery tests implemented at three spiking levels, namely 100, 200, and 500 µg∙kg^-1, generated the results of 71.95 %-113.97 %, while the intra- and inter-day precisions were 0.27 %-17.94 %, indicating that this method had excellent accuracy and precision.

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.

Plant nanobionics: Fortifying food security via engineered plant productivity

The world's human population is increasing exponentially, increasing the demand for high-quality food sources. As a result, there is a major global concern over hunger and malnutrition in developing countries with limited food resources. To address this issue, researchers worldwide must focus on developing improved crop varieties with greater productivity to overcome hunger. However, conventional crop breeding methods require extensive periods to develop new varieties with desirable traits. To tackle this challenge, an innovative approach termed plant nanobionics introduces nanomaterials (NMs) into cell organelles to enhance or modify plant function and thus crop productivity and yield. A comprehensive review of nanomaterials affect crop yield is needed to guide nanotechnology research. This article critically reviews nanotechnology applications for engineering plant productivity, seed germination, crop growth, enhancing photosynthesis, and improving crop yield and quality, and discusses nanobionic approaches such as smart drug delivery systems and plant nanobiosensors. Moreover, the review describes NM classification and synthesis and human health-related and plant toxicity hazards. Our findings suggest that nanotechnology application in agricultural production could significantly increase crop yields to alleviate global hunger pressures. However, the environmental risks associated with NMs should be investigated thoroughly before their widespread adoption in agriculture.

Toxicity and ecological risk assessment for two AhR agonistic pesticides mepanipyrim and cyprodinil and their metabolites

Mepanipyrim and cyprodinil are widely used to control and/or prevent fungal diseases in fruit culture. They are frequently detected in the aquatic environment and some food commodities. Different from TCDD, mepanipyrim and cyprodinil are more easily metabolised in the environments. However, the risk of their metabolites to the ecological environment is unclear and needs to be further confirmed. In this study, we investigated the temporal pattern of mepanipyrim- and cyprodinil-induced CYP1A and AhR2 expression and EROD enzyme activity at different time frames during zebrafish embryonic and larval development. Then, we assessed the ecological risk of mepanipyrim, cyprodinil, and their metabolites to aquatic organisms. Our results showed that mepanipyrim and cyprodinil exposure could increase the expression level of cyp1a and ahr2 genes and EROD activity by a dynamic pattern in different developmental stages of zebrafish. Besides, their several metabolites showed strong AhR agonistic activity. Importantly, these metabolites could cause potential ecological risks to aquatic organisms and should be paid more attention to. Our results would provide an important reference value for environmental pollution control and the use management of mepanipyrim and cyprodinil.

Role of the tyrosine aminotransferase AccTATN gene in the response to pesticide and heavy metal stress in Apis cerana cerana

Tyrosine aminotransferase (TATN) is the first enzyme involved in the metabolic degradation of tyrosine, and it plays an important role in tyrosine detoxification and helps the body resist oxidative damage. However, the function of TATN in Apis cerana cerana (A. c. cerana) remains unclear. To explore the role of TATN in the response to pesticide and heavy metal stress in A. c. cerana, AccTATN was isolated and identified. AccTATN was highly expressed in the integument and the adult stage. Exposure to multiple pesticides and heavy metal stress upregulated AccTATN expression. RNA interference experiments showed that silencing AccTATN reduced the resistance of A. c. cerana to glyphosate and avermectins stress. The expression of antioxidant-related genes and the activity of antioxidant enzymes were reduced after AccTATN was silenced, leading to the accumulation of oxidative damage. Overexpression of the recombinant AccTATN protein in a prokaryotic system also confirmed its role in heavy metal stress and improved antioxidant capacity. Our study showed that AccTATN may promote resistance to pesticide and heavy metal stress by regulating the antioxidant capacity of A. c. cerana. This study provides a valuable theoretical basis for A. c. cerana conservation.

Isolation and characterization of Lactobacillus casei A14.2, a strain with immunomodulating activity on Apis mellifera

Considering the economic and environmental role played by bees and their present threats it is necessary to develop food supplements favoring their health. The aim of this work was to isolate and characterize an immunomodulating probiotic capable to improve the health of honeybee colonies. For this purpose, bacterial strains were isolated from Apis mellifera bees (N = 180) obtained at three apiaries. A total of 44 strains were isolated and 9 of them were identified as Lactobacillus having the capacity to grow under saccharose osmotic stress, at pH 4.0 and possessing a wide susceptibility to antibiotics. Results allowed to select two strains but finally only one of them, strain A14.2 showed a very significant immunomodulating activity. This strain increased the expression of mRNA codifying the antimicrobial peptides 24 h post-administration. We evaluated its growth kinetics under aerobic and microaerobic conditions and its survival in the presence of high concentrations of saccharose. Results demonstrated that Lactobacillus casei A14.2 strain was highly tolerant to oxygen and that it was able to adapt to saccharose enriched environments (50% and 100% w/v). Finally, L. casei A14.2 strain was administered monthly during summer and early fall to 4 honeybee colonies (2 controls and 2 treatments). The results showed a gradual sustained decrease of infestation (p < 0.05) by the pathogenic Nosema spp. but no reduction in the infestation by the mite Varroa destructor. These results suggest that the administration of this potential probiotic, may increase the resistance of honeybee colonies to infectious diseases caused by Nosema spp.

Bionanotechnology in Agriculture: A One Health Approach

Healthy eating habits are one of the requirements for the health of society. In particular, in natura foods are increasingly encouraged, since they have a high concentration of nutrients. However, these foods are often grown in the presence of agrochemicals, such as fertilizers and pesticides. To increase crop productivity and achieve high vigor standards in less time, farmers make excessive use of agrochemicals that generate various economic, environmental, and clinical problems. In this way, bionanotechnology appears as an ally in developing technologies to improve planting conditions, ranging from the health of farmers and consumers to the production of new foods and functional foods. All these improvements are based on the better use of land use in synergy with the lowest generation of environmental impacts and the health of living beings, with a view to the study and production of technologies that take into account the concept of One Health in its processes and products. In this review article, we will address how caring for agriculture can directly influence the quality of the most desired foods in contemporary society, and how new alternatives based on nanotechnology can point to efficient and safe solutions for living beings on our planet.

Simultaneous detection of four pesticides in agricultural products by a modified QuEChERS method and LC-MS/MS

A modified QuEChERS pretreatment method and LC-MS/MS technique were performed to simultaneously determine four pesticide (Hexachlorophene, Dinex, Dinosam, Dinoterb) residues in agricultural products. Through the optimization of LC-MS/MS detection parameters in SIM mode, the optimal instrument conditions are obtained. The modified QuEChERS method was used to pretreat the samples. Solid phase extractants PSA, C18 and GCB were used for sample purification. The research results showed that the correlation coefficients of the four pesticides were all greater than 0.991, which had a good linear relationship. The limits of quantitation (LOQ) of the four pesticides were 0.05-0.56 μg/kg. The recoveries were 70.51-113.20% with relative standard deviations (RSDS) of 1.6-11.2%. The developed method can provide reliable data support for the subsequent simultaneous detection of these four pesticides.

Role of c-Jun NH2 -terminal kinase-mediated mitogen-activated protein kinase pathway in response to pesticides in Apis cerana cerana

The mitogen-activated protein kinase (MAPK) cascade pathway plays an important role in regulating stress responses. The function of the c-Jun NH₂ -terminal kinase (JNK), a component of the MAPK cascade pathway, in Apis cerana cerana (Acc) remains unclear. Here, JNK was isolated and identified from Acc. Bioinformatics analyses revealed there is a typical serine/threonine protein kinase catalytic domain in the AccJNK protein. An expression profile analysis showed that AccJNK was significantly induced by pesticide treatments. To further explore the functional mechanisms of AccJNK, a yeast 2-hybrid screen was performed, activator protein-1 (AP-1) was screened as the interaction partner of AccJNK, and the interaction relationship was further verified by pull-down assay. Quantitative real-time polymerase chain reaction showed the expression pattern of AccAP-1 was similar to that of AccJNK. After a knockdown of AccJNK or AccAP-1 by RNA interference, the survival rate of Acc after pesticide treatments increased. Additionally, the expression levels of antioxidant-related genes and the activities of antioxidant enzymes increased, suggesting that the knockdown of AccJNK or AccAP-1 increased the antioxidant capacity of bees. Our study revealed that the JNK-mediated MAPK pathway responds to pesticide stress by altering the antioxidant capacity of Acc.

Pesticides in honey: bibliographic and bibliometric analysis towards matrix quality for consumption

Abstract Honey is a matrix noted for its wide consumption as a sweetener and its anti-inflammatory, antioxidant, and antimicrobial properties; however, its physicochemical quality can be compromised by the presence of toxicants such as pesticides. This review aims to gather recent information on pesticides in honey from the approach to their detection, understanding, and adverse effects on human health. A bibliographic and bibliometric analysis was carried out in academic databases limited to the last five and thirty years, respectively, comprising the keywords “honey”, “pesticides” and their types of pesticides or the agrochemical compound directly. It was found that there are about 30 pesticides detected in honey, in which organochlorine, organophosphate, and neonicotinoid compounds stood out for their concentrations concerning Maximum Residue Levels (MRL). Their physicochemical alteration was not well explored beyond slight variations in brightness and manganese concentration, and its consumption may have repercussions on human reproductive health. It was also determined that there was limited development on the scientific subject seeing that it is important to explore and investigate more on the issue due to the great impact of honey as a product of high consumption at a global level.

Pesticide residues in commonly consumed food from five localities of Burkina Faso: occurrence and health risk assessment

Monitoring data for pesticides are generally scarce in many countries of the world, especially in developing countries. In Burkina Faso, there are few scientific data on the occurrence and concentrations of pesticide residues in staple foods found in local markets. Using QuEChERS extraction method and gas chromatography-mass spectrometry, samples of commonly eaten foods from five localities of Burkina Faso were evaluated by targeting more than 40 pesticides. It appears that 58.1% of all the collected samples exhibited at least one or more pesticide residues. Among those, 36.5% of the samples had at least one pesticide with a concentration above the maximum residue level (MRL) value. Unfortunately, no MRL data was available for dried fish which is a widely consumed food in this part of Africa. Simazine was found in tomatoes, pyrethroids in cereals, while dried fish contained most of the pesticides detected. The assessment of long-term health risks revealed that dieldrin quantified in dried fish showed more than 250% of acceptable daily intake which was then labelled as unacceptable high risk. For hazardous foods, more sampling should be carried out for a better assessment of the health risks involved.

Binding and Detoxification of Insecticides by Potentially Probiotic Lactic Acid Bacteria Isolated from Honeybee (Apis mellifera L.) Environment-An In Vitro Study

Lactic acid bacteria (LAB) naturally inhabiting the digestive tract of honeybees are known for their ability to detoxify xenobiotics. The effect of chlorpyrifos, coumaphos, and imidacloprid on the growth of LAB strains was tested. All strains showed high resistance to these insecticides. Subsequently, the insecticide binding ability of LAB was investigated. Coumaphos and chlorpyrifos were bound to the greatest extent (up to approx. 64%), and imidacloprid to a much weaker extent (up to approx. 36%). The insecticides were detected in extra- and intracellular extracts of the bacterial cell wall. The ability of selected LAB to reduce the cyto- and genotoxicity of insecticides was tested on two normal (ovarian insect Sf-9 and rat intestinal IEC-6) cell lines and one cancer (human intestinal Caco-2) cell line. All strains exhibited various levels of reduction in the cyto- and genotoxicity of tested insecticides. It seems that coumaphos was detoxified most potently. The detoxification abilities depended on the insecticide, LAB strain, and cell line. The detoxification of insecticides in the organisms of honeybees may reduce the likelihood of the penetration of these toxins into honeybee products consumed by humans and may contribute to the improvement of the condition in apiaries and honeybee health.

Understanding Italian Consumers' Perception of Safety in Animal Food Products

The concept of food safety is still underexplored among consumers, especially in relationship with the perception of food technology. Through an online survey (n = 489), this study explored: I, how perceived safety is related to products obtained with different technological treatments and described with different commercial information; II, the role of food technology neophobia (FTN) in consumers' safety perception of animal food products. The technological transformation and commercial information significantly affected the perceived safety in all product categories. Milk and eggs were associated with a high number of perceived hazards (with similar patterns), while honey to the lowest. The certification 'organic' positively affected the safety perception of eggs and honey. With the increase of the distance in product origin (local/regional vs. Extra-European) the perceived safety consistently decreased. FTN affected the perceived safety of milk and eggs, depending on the degree of familiarity with the technologies of production. Highly FT neophobic people are perceived as less safe than low FT neophobic people with few familiar products with a higher technological degree of transformation. Results expand the knowledge in people's attitude towards animal products, particularly considering the technology perception. The outputs may interest policy-makers and food companies, in rethinking the communication strategy concerning food safety.

Dual-Color 2D Lead-Organic Framework with Two-Fold Interlocking Structures for the Detection of Nitrofuran Antibiotics and 2,6-Dichloro-4-nitroaniline

The misuse of organic pollutants such as nitrofuran antibiotics (NFAs) and 2,6-dichloro-4-nitroaniline (DCN) has become a hot topic of global concern, and developing rapid, efficient, and accurate techniques for detecting NFAs and pesticides in water is a major challenge. Here, we designed a novel lead-based anion 2D metal-organic framework (MOF){[(CH₃)₂NH₂]₂[Pb(TCBPE)(H₂O)₂]}_n (F3) with interlocking structures, in which TCBPE stands for 1,1,2,2-tetra(4-carboxylbiphenyl)ethylene. Powder X-ray diffraction and thermogravimetric analysis revealed that F3 has excellent chemical and solvent stability. It is worth noting that F3 has a grinding discoloration effect. The solvent-protected grinding approach achieved F3B with a high quantum yield (QY = 73.77%) and blue fluorescence, while the direct grinding method produced F3Y with a high quantum yield (QY = 37.27%) and yellow-green fluorescence. Importantly, F3B can detect NFAs in water rapidly and sensitively while remaining unaffected by other antibiotics. F3Y can identify DCN in water quickly and selectively while remaining unchanged by other pesticides. F3B demonstrated high selectivity and rapid response to NFAs at a limit of detection (LOD) as low as 0.26 μM, while F3Y indicated high selectivity and responded quickly to DCN in water at an LOD as low as 0.14 μM. The method was successfully applied to detect NFAs in actual water samples of the fish tanks and ponds as well as the pesticide DCN in soil samples. The recovery rates were 97.0-105.15% and 102.2-106.48%, and the relative standard deviations were 0.63-1.45% and 0.29-1.69%, respectively. In addition, F3B and F3Y can be made into fluorescent test papers for the visual detection of NFAs and DCN, respectively. Combined with experiments and density functional theory calculations, the mechanism of fluorescence quenching of MOFs by target analytes was also revealed.

Neonicotinoids residues in the honey circulating in Chinese market and health risk on honey bees and human

China is the largest beekeeping and honey consumption country globally. Neonicotinoids in honey can pose adverse effects on honey bees and human, but data on neonicotinoids residues in honey and its health risk remain limited in China. A total of 94 honey samples were selected from Chinese market based on production region and sale volume in 2020. Eight neonicotinoids and four metabolites were determined by liquid chromatography coupled to mass spectrometry. Health risk of neonicotinoids in honey on honey bees and human was assessed by hazard quotient (HQ) and hazard index (HI). Neonicotinoids and their metabolites were overall detected in 97.9% of honey samples. Acetamiprid, thiamethoxam, and imidacloprid were top three dominant neonicotinoids in honey with the detection frequencies of 92.6%, 90.4%, and 73.4%, respectively. For honey bees, 78.7% of honey samples had a HI larger than one based on the safety threshold value of sublethal effects. Top three neonicotinoids with the highest percent proportion of HQ larger than one for honey bees were acetamiprid (43.6%), imidacloprid (31.9%), and thiamethoxam (24.5%) and their maximum HQs were 420, 210, and 41, respectively. Based on oral median lethal doses for honey bees, both HQ and HI were lower than one in all honey samples. For human, both HQ and HI were lower than one based on acceptable daily intakes in all honey samples. Neonicotinoids concentrations and detection frequencies in honey samples and its health risk varied with production region, commercial value of nectariferous plants, number of nectariferous plants, and sale price. The results suggested extensive residues of neonicotinoids in honey in Chinese market with a variation by the characteristics of honey. The residues were likely to affect the health of honey bees, but showed no detectable effect on human health.

Reciprocal interactions between anthropogenic stressors and insect microbiota

Insects play many important roles in nature due to their diversity, ecological role, and impact on agriculture or human health. They are directly influenced by environmental changes and in particular anthropic activities that constitute an important driver of change in the environmental characteristics. Insects face numerous anthropogenic stressors and have evolved various detoxication mechanisms to survive and/or resist to these compounds. Recent studies highligted the pressure exerted by xenobiotics on insect life-cycle and the important role of insect-associated bacterial microbiota in the insect responses to environmental changes. Stressor exposure can have various impacts on the composition and structure of insect microbiota that in turn may influence insect biology. Moreover, bacterial communities associated with insects can be directly or indirectly involved in detoxification processes with the selection of certain microorganisms capable of degrading xenobiotics. Further studies are needed to assess the role of insect-associated microbiota as key contributor to the xenobiotic metabolism and thus as a driver for insect adaptation to polluted habitats.

Residues of Pesticides and Heavy Metals in Polish Varietal Honey

The levels of chemical pollutants were determined in 30 samples of varietal honey from southeastern Poland, including 223 pesticides (insecticides, herbicides, fungicides, acaricides, plant growth regulators, and veterinary drugs) and 5 heavy metals (Pb, Cd, Hg, Cu, and Zn). In 10% of the samples, no pesticide residues were found. The most frequently identified pesticides were thiacloprid (90% of the samples, max 0.337 mg/kg), acetamiprid (86.6%, max 0.061 mg/kg), carbendazim (60%, max 0.049 mg/kg), DMF (56.6%, max 0.038 mg/kg), total amitraz (53.3%, max 0.075 mg/kg), thiamethoxam (26.6%, max 0.004 mg/kg), thiacloprid-amide (13.3%, max 0.012 mg/kg), dimethoate (10%, max 0.003 mg/kg), azoxystrobin (10%, max 0.002 mg/kg), tebuconazole (6.66%, max 0.002 mg/kg), and boscalid (3.33%, max 0.001 mg/kg). The acceptable limits for the compounds were not exceeded in any sample. The Pb content ranged between 0.044 and 0.081 mg/kg. The concentration of Hg and Cd did not exceed 5.0 µg/kg and 0.02 mg/kg, respectively. The honey variety significantly (p < 0.01) influenced the content of Cu, which ranged from 0.504 (rapeseed honey) to 1.201 mg/kg (buckwheat). A similar tendency (p > 0.05) was observed for the Zn content, which ranged from 0.657 mg/kg (linden) to 2.694 mg/kg (buckwheat). Honey produced in southeastern Poland was shown to be safe for human consumption.

Dispersive Membrane Microextraction of Substituted Phenols from Honey Samples and a Brief Outlook on Its Sustainability Using Analytical Eco-Scale and Analytical GREEnness Metric Approach

Honey is part and parcel of our daily nutrition, but in recent times it has been reported to be tainted by the presence of polar substituted phenols purported from the use of pesticides, herbicides, antimicrobial agents, etc. Honey’s viscous nature and matrix complexity often result in analytical chemists resorting to derivatization for the detection of polar analytes such as substituted phenols. This study aims to overcome the matrix effect without derivatization and offer a more sustainable solution with notable sensitivity and selectivity using dispersive membrane microextraction alongside high-performance liquid chromatography (DMME–HPLC) with sporopollenin–methylimidazolium-based mixed matrix membrane (Sp–MIM-MMM). The DMME–HPLC approach successfully determined the presence of mono- and disubstituted phenols from unspiked honey samples with concentrations ranging from 7.8 to 154.7 ng/mL. The sustainability of the proposed method was also validated using the Analytical Eco-Scale (AES) and the Analytical GREEnness Metric (AGREE) where an excellent score of 94 and the encouraging score of 0.72 were recorded, respectively.

Development of an online μ-matrix cartridge extraction method for fipronil extraction in contaminated soils

Nowadays, environment fate and behavior of pesticides in soil is still not fully understood due to the lack of standardized soil extraction method. In this work, a soil-filled micro-matrix cartridge was online combined with high performance liquid chromatography-mass spectrometry (HPLC-MS) through a six-way valve for the simultaneous extraction and determination of residual fipronil in soil. Compared with conventional extraction methods, such as hydroxypropyl-β-cyclodextrin (HPCD) extraction, shaking extraction, ultrasonic-assisted extraction (UAE), three-step extraction and matrix solid phase dispersion (MSPD), the novel, miniaturized, and integrated online micro-matrix cartridge extraction (online μ-MCE) method exhibited better performance in terms of desorption efficiency (99.4%), analysis time, solvent consumption, sensitivity, and automation. In sequential extraction, online μ-MCE could further desorb fipronil from the extracted soil with the percentage of 1.05%-58.55%. High recovery of 92.69% obtained for the ISO certificated test-soil verified the satisfactory accuracy of the method. Besides, its wide universality was also validated in three variables: 1) various pesticides-soil interactions, 2) four types of compounds (aromatic hydrocarbons, carboxylic acids, alcohols and aldehydes), and 3) three types of soils (sandy soil, silty loam and silty clay). The superior desorption capacity might be attributed to the instantaneously increased high-pressure, continuous flow dynamic desorption and short residence time. The present encouraging findings might shed light on new ways to develop a mild, highly efficient, reliable and one-fit-all extraction method toward pesticide contaminated soil.

Pesticide residues in beebread and honey in Apis cerana cerana and their hazards to honey bees and human

The residue of pesticides in bee products such as beebread and honey threaten the survival of pollinators and human health. Apis cerana cerana is one of the leading managed honey bees in China. However, little is known about the residues of pesticides in hive products of A. c. cerana in China. Here, we investigated the pesticide residues in beebread and honey. The risk of detected residues of pesticides to honey bees was evaluated with hazard quotient (HQ) and BeeREX. Furthermore, we assessed the chronic and acute risks to humans according to the dietary exposure. Our results suggest that the pesticide residues detection ratio (25.4% for beebread and 2.8% for honey) and the concentrations of these residues is lower than previously reported. Additional risk assessments indicate that the residue levels of pesticides in tested honey of A. c. cerana do not pose a risk for human consumers. Among all identified pesticides, only thiamethoxam raises the concern for further risk assessment in the risk evaluation of honey bee colonies and thiamethoxam was safe for colonies in higer tier studies.

Applications of Alginate-Based Nanomaterials in Enhancing the Therapeutic Effects of Bee Products

Since the ancient times, bee products (i.e., honey, propolis, pollen, bee venom, bee bread, and royal jelly) have been considered as natural remedies with therapeutic effects against a number of diseases. The therapeutic pleiotropy of bee products is due to their diverse composition and chemical properties, which is independent on the bee species. This has encouraged researchers to extensively study the therapeutic potentials of these products, especially honey. On the other hand, amid the unprecedented growth in nanotechnology research and applications, nanomaterials with various characteristics have been utilized to improve the therapeutic efficiency of these products. Towards keeping the bee products as natural and non-toxic therapeutics, the green synthesis of nanocarriers loaded with these products or their extracts has received a special attention. Alginate is a naturally produced biopolymer derived from brown algae, the desirable properties of which include biodegradability, biocompatibility, non-toxicity and non-immunogenicity. This review presents an overview of alginates, including their properties, nanoformulations, and pharmaceutical applications, placing a particular emphasis on their applications for the enhancement of the therapeutic effects of bee products. Despite the paucity of studies on fabrication of alginate-based nanomaterials loaded with bee products or their extracts, recent advances in the area of utilizing alginate-based nanomaterials and other types of materials to enhance the therapeutic potentials of bee products are summarized in this work. As the most widespread and well-studied bee products, honey and propolis have garnered a special interest; combining them with alginate-based nanomaterials has led to promising findings, especially for wound healing and skin tissue engineering. Furthermore, future directions are proposed and discussed to encourage researchers to develop alginate-based stingless bee product nanomedicines, and to help in selecting suitable methods for devising nanoformulations based on multi-criteria decision making models. Also, the commercialization prospects of nanocomposites based on alginates and bee products are discussed. In conclusion, preserving original characteristics of the bee products is a critical challenge in developing nano-carrier systems. Alginate-based nanomaterials are well suited for this task because they can be fabricated without the use of harsh conditions, such as shear force and freeze-drying, which are often used for other nano-carriers. Further, conjunction of alginates with natural polymers such as honey does not only combine the medicinal properties of alginates and honey, but it could also enhance the mechanical properties and cell adhesion capacity of alginates.

Neonicotinoids exposure assessment in Africanized honey bees (Apis mellifera L.) by using an environmentally-friendly sample preparation technique followed by UPLC-MS/MS

A miniaturized QuEChERS extraction method followed by ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was developed to analyze thiamethoxam and imidacloprid in 0.3 g of lyophilized Africanized honey bees (Apis mellifera L.). The work aimed to estimate honey bees' exposure to pesticides at the nanogram/gram (ng g^-1) levels, using small sample and reagent quantities. Low amounts of solvents and salts were employed - 15× less than used in traditional methods. Average recoveries ranged from 64.5% to 99.7%, with repeatability below 20% for samples spiked at 3 and 167 ng g^-1. LOD and LOQ were 0.7, and 3 ng g^-1 for both pesticides. Applying the proposed approach, honey bee samples from different apiaries from the State of São Paulo (Brazil) were analyzed. The pesticides were detected in concentrations between 7.0 and 27.0 ng g^-1. Thus, the proposed method can be used as a greener alternative to analyze the two neonicotinoids at trace levels in small quantities of bees, consequently saving chemicals and waste.

Exploring a novel deep eutectic solvents combined with vortex assisted dispersive liquid-liquid microextraction and its toxicity for organophosphorus pesticides analysis from honey and fruit samples

A novel deep eutectic solvents (DES) was successfully applied as an emulsifier in vortex assisted liquid-liquid microextraction (VALLME) coupled with gas chromatography-mass spectrometry for the determination of organophosphorus pesticides in honey and fruit samples. Based on the result of toxicity study, DES provides new opportunities for the safe delivery and application. The predominant parameters affecting extraction efficiency were thoroughly optimized and studied in detail. Under optimum parameters, the calibration curve was determined in the concentration range of 0.1 to 200 µgL^-1 with excellent determination coefficients values of 0.9989 to 0.9999. Limit of detection and limit of quantification were found to be 0.01 - 0.09 µgL^-1 and 0.03 - 0.2 µgL^-1, respectively. Application of the developed method to honey and fruit samples gave acceptable recovery values 83 - 109% with relative standard deviation below than 9.5%. The suggested approach has also proven to be simple, cost-effective, rapid, and non-toxic in nature.

Interaction of Insecticides and Fungicides in Bees

Honeybees and wild bees are among the most important pollinators of both wild and cultivated landscapes. In recent years, however, a significant decline in these pollinators has been recorded. This decrease can have many causes including the heavy use of biocidal plant protection products in agriculture. The most frequent residues in bee products originate from fungicides, while neonicotinoids and, to a lesser extent, pyrethroids are among the most popular insecticides detected in bee products. There is abundant evidence of toxic side effects on honeybees and wild bees produced by neonicotinoids, but only few studies have investigated side effects of fungicides, because they are generally regarded as not being harmful for bees. In the field, a variety of substances are taken up by bees including mixtures of insecticides and fungicides, and their combinations can be lethal for these pollinators, depending on the specific group of insecticide or fungicide. This review discusses the different combinations of major insecticide and fungicide classes and their effects on honeybees and wild bees. Fungicides inhibiting the sterol biosynthesis pathway can strongly increase the toxicity of neonicotinoids and pyrethroids. Other fungicides, in contrast, do not appear to enhance toxicity when combined with neonicotinoid or pyrethroid insecticides. But the knowledge on possible interactions of fungicides not inhibiting the sterol biosynthesis pathway and insecticides is poor, particularly in wild bees, emphasizing the need for further studies on possible effects of insecticide-fungicide interactions in bees.

Raman spectrum classification based on transfer learning by a convolutional neural network: Application to pesticide detection

Pesticide detection is of tremendous importance in agriculture, and Raman spectroscopy/Surface-Enhanced Raman Scattering (SERS) has proven extremely effective as a stand-alone method to detect pesticide residues. Machine learning may be able to automate such detection, but conventional algorithms require a complete database of Raman spectra, which is not feasible. To bypass this problem, the present study describes a transfer learning method that improves the algorithm's accuracy and speed to extract features and classify Raman spectra. The transfer learning model described here was developed through the following steps: (1) the classification model was pre-trained using an open-source Raman spectroscopy database; (2) the feature extraction layer was saved after training; and (3) the training model for the Raman spectroscopy database was re-established while using self-tested pesticides and keeping the feature extraction layer unchanged. Three models were evaluated with or without transfer learning: CNN-1D, Resnet-1D, and Inception-1D, and they have improved the accuracy of spectrum classification by 6%, 2%, and 3%, with reduced training time and increased curve smoothness. These results suggest that transfer learning can improve the feature extraction capability and therefore accuracy of Raman spectroscopy models, expanding the range of Raman-based applications where transfer learning model can be used to identify the spectra of different substances.

Recent advances in synthesis and modification of carbon dots for optical sensing of pesticides

Serious threat from pesticide residues to the ecosystem and human health has become a global concern. Developing reliable methods for monitoring pesticides is a world-wide research hotspot. Carbon dots (CDs) with excellent photostability, low toxicity, and good biocompatibility have been regarded as the potential substitutes in fabricating various optical sensors for pesticide detection. Based on the relevant high-quality publications, this paper first summarizes the current state-of-the-art of the synthetic and modification approaches of CDs. Then, a comprehensive overview is given on the recent advances of CDs-based optical sensors for pesticides over the past five years, with a particular focus on photoluminescent, electrochemiluminescent and colorimetric sensors regarding the sensing mechanisms and design principles by integrating with various recognition elements including antibodies, aptamers, enzymes, molecularly imprinted polymers, and some nanoparticles. Novel functions and extended applications of CDs as signal indicators, catalyst, co-reactants, and electrode surface modifiers, in constructing optical sensors are specially highlighted. Beyond an assessment of the performances of the real-world application of these proposed optical sensors, the existing inadequacies and current challenges, as well as future perspectives for pesticide monitoring are discussed in detail. It is hoped to provide powerful insights for the development of novel CDs-based sensing strategies with their wide application in different fields for pesticide supervision.