Presence and distribution of pesticides in apicultural products: A critical appraisal

Underexplored food safety hazards of beekeeping products: Key knowledge gaps and suggestions for future research

These days, a growing consumer demand and scientific interest can be observed for nutraceuticals of natural origin, including apiculture products. Due to the growing emphasis on environmental protection, extensive research has been conducted on the pesticide and heavy metal contamination of bee products; however, less attention is devoted on other food safety aspects. In our review, scientific information on the less-researched food safety hazards of honey, bee bread, royal jelly, propolis, and beeswax are summarized. Bee products originating from certain plants may inherently contain phytotoxins, like pyrrolizidine alkaloids, tropane alkaloids, matrine alkaloids, grayanotoxins, gelsemium alkaloids, or tutin. Several case studies evidence that bee products can induce allergic responses to sensitive individuals, varying from mild to severe symptoms, including the potentially lethal anaphylaxis. Exposure to high temperature or long storage may lead to the formation of the potentially toxic 5-hydroxymethylfurfural. Persistent organic pollutants, radionuclides, and microplastics can potentially be transferred to bee products from contaminated environmental sources. And lastly, inappropriate beekeeping practices can lead to the contamination of beekeeping products with harmful microorganisms and mycotoxins. Our review demonstrates the necessity of applying good beekeeping practices in order to protect honeybees and consumers of their products. An important aim of our work is to identify key knowledge gaps regarding the food safety of apiculture products.

Simultaneous analysis of pesticides and mycotoxins in primary processed foods: The case of bee pollen

Primary Processed Foods are a class of food items that are ready for consumption after minimal processing in the supply chain. These products are ubiquitous in our daily diet, but so far a limited number of studies dealt with the optimization of quality control methods to check their content of contaminants. Among primary processed foods, bee pollen is a nutritionally acclaimed food supplement, whose contamination with pesticides and mycotoxins has been largely proven. For this reason, the present study aimed at optimizing for the first time a comprehensive LC-MS/MS method capable of analyzing 282 pesticides and 8 mycotoxins in bee pollen. To obtain a suitable method, two extraction procedures (QuEChERS and Accelerated Solvent Extraction), as well as different chromatographic gradients and columns, were tested. The optimized methodology, comprehending an extraction based on semi-automated QuEChERS, and an analytical method including inert LC column technology, was validated and applied to a sample set of 34 bee pollens. The analyzed samples collectively showed the presence of 41 pesticides and 1 mycotoxin.

Spatiotemporal variability of pesticides concentration in honeybees (Apis mellifera) and their honey from western Mexico. Risk assessment for honey consumption

The study conducted in the state of Colima, western Mexico, aimed to assess the 1) occurrence, 2) temporal variability, 3) spatial variability, and 4) potential risk for honeybees and human consumption of pesticide-contaminated honey. For that purpose, 48 pesticides were determined in bees and their honey during both dry and wet seasons. The research considered two variables: land use categorization (irrigated agriculture, rainfed agriculture, grassland, and forest area) and location (coastal, valley, and mountain). Bee and honey samples were collected, pre-treated using solid-phase extraction (SPE), and analyzed using LC-MS/MS and GC-MS techniques. Occurrence: of the total number of pesticides, 17 were detected in the bee samples and 12 in the honey samples. The pesticides with the highest concentrations in the bee samples were glufosinate ammonium, picloram, and permethrin, while in the honey samples, picloram, permethrin, and atrazine were the most prevalent. Temporal variability: analyses revealed significant differences between dry and wet seasons for glufosinate ammonium and DEET in bee samples and only for glufosinate ammonium in honey samples. Spatial variability: analyses showed a trend in the number of detected pesticides, with irrigated agriculture areas having the highest detection and grassland areas having the least. The human potential risk assessment of contaminated honey consumption indicated no risk. The bee's potential risk for consumption of pesticides contaminated honey revealed chronic effects due to permethrin in a general scenario, and carbofuran, diazinon and permethrin in the worst scenario, and potential risk of acute effects by permethrin. The findings of this study contribute to understanding the contamination levels of pesticides in bees and their honey, emphasizing the importance of monitoring and mitigating the adverse effects of pesticide exposure on bee populations and environmental health.

Study of Physicochemical Quality and Organic Contamination in Algerian Honey

Honey is a natural product extensively consumed in the world for its nutritional and healthy properties. However, residues of pesticides and environmental contaminants can compromise its quality. For this reason, the physicochemical parameters, and the organic contamination of monofloral and multifloral honey from three regions of Algeria (Tiaret, Laghouat, and Tindouf) were monitored to evaluate the quality of the honey and its safety for consumers. In general, the results obtained from the physicochemical analyses were in line with the EU standards. In terms of contamination, pesticides authorised and used in Algerian agriculture (metalaxyl-M and cyromazine), as well as a banned pesticide (carbaryl), were found in almost all the samples. However, only the concentration of cyromazine was higher than the relative EU maximum residue levels. PCB 180, PCB 189, anthracene, fluorene, and phenanthrene were mainly detected. All the honey shows traces of DiBP, DBP, DEHP, and DEHT, but no traces of bisphenols were found. Moreover, according to the dietary exposure assessment, a small amount of Algerian honey can be safely consumed. Overall, the data from this study should motivate the Algerian government to enhance their monitoring activities in beekeeping and to find solutions for implementing more sustainable agricultural practices harmonising with international legislation.

Development and validation of an analytical methodology based on solvent extraction and gas chromatography for determining pesticides in royal jelly and propolis

We propose a new analytical methodology to determine seven pesticides (atrazine, chlorpyrifos, chlorfenvinphos, α-endosulfan, bromopropylate, coumaphos, and τ-fluvalinate) in royal jelly and propolis products using gas chromatography-mass spectrometry. Sample treatment, with minor modifications for propolis, consisted of a solvent extraction with a hexane and isopropanol mixture, and a further clean-up step. Meanwhile, chromatographic analysis (<25 min) was performed in a DB-5MS column under programmed temperature conditions. In all cases we validated the method in terms of selectivity, limits of detection (0.1-2.8 μg kg-1) and quantification (0.3-9.2 μg kg-1), linearity, matrix effect (<±20 %), trueness (recoveries between 93 % and 118 %), and precision (relative standard deviation < 11 %). All royal jelly liquid dietary supplements were positive for chlorfenvinphos and, in the case of one of them, for α-endosulfan; chlorfenvinphos was determined in some fresh royal jelly samples, and no pesticide residues were detected in the propolis samples analysed.

Environmental assessment of PAHs through honey bee colonies - A matrix selection study

The steady conditions of temperature, humidity and air flux within beehives make them a valuable location for conducting environmental monitoring of pollutants such as PAHs. In this context, the selection of an appropriate apicultural matrix plays a key role in these monitoring studies, as it maximizes the information that will be obtained in the analyses while minimizing the inaccurate results. In the present study, three apicultural matrices (honey bees, pollen and propolis) and two passive samplers (APIStrips and silicone wristbands) are compared in terms of the number and total load of PAHs detected in them. Samplings took place in a total of 11 apiaries scattered in Austria, Denmark, and Greece, with analyses performed by GC-MS/MS. Up to 14 different PAHs were identified in silicone wristbands and pollen, whereas the remaining matrices contained a maximum of five contaminants. Naphthalene, 1-methylnaphthalene, 2-methylnaphthalene, and pyrene were found to be the most prevalent substances in the environment. Recovery studies were also performed; these suggested that the chemical structure of APIStrips is likely to produce very strong interactions with PAHs, thus hindering the adequate desorption of these substances from their surface. Overall, silicone wristbands placed inside the beehives proved the most suitable matrix for PAH monitoring through honey bee colonies.

Determination of highly polar anionic pesticides in beehive products by hydrophilic interaction liquid chromatography coupled to mass spectrometry

The analysis of highly polar pesticides is challenging due to their unique physicochemical properties, requiring specialized chromatographic techniques for their accurate and sensitive detection. Furthermore, the high level of co-extracted polar matrix components that can co-elute with the analytes can interfere with the analysis. Consequently, there is lack of pesticide monitoring data, as the European Food Safety Authority has pointed out. This article explores the overcoming of such difficulties in the analysis of these compounds. Analytical methodologies for the extraction, clean-up, and direct determination of 11 highly polar anionic pesticides, including glyphosate, glufosinate, ethephon, fosetyl-aluminium, and their related metabolites in complex food matrices such as honey and pollen by hydrophilic interaction liquid chromatography coupled to tandem mass spectrometry were successfully developed and validated. Solid-phase extraction and micro-solid-phase extraction employing strong anion exchange (SAX) cartridges were implemented for clean-up. The automation and miniaturization of SAX clean-up for these compounds were achieved for the first time. For method validation, SANTE/11312/2021 guideline was followed. Recoveries were between 70 and 120%, with RSDs below 20%. Limits of quantitation ranged from 0.005 to 0.020 mg kg-1. Linearity was evaluated from 0.002 to 0.200 mg kg-1. Matrix effects were assessed, showing medium to low signal suppression for most compounds. AMPA and glufosinate presented the highest signal suppression, but it was reduced after SAX clean-up. Analysis of real honey and pollen samples revealed the occurrence of the studied compounds in beehive products and showed the applicability of the validated methodologies for routine control of these complex samples.

Biomarker responses and lethal dietary doses of tau-fluvalinate and coumaphos in honey bees: Implications for chronic acaricide toxicity

Evidence suggests that acaricide residues, such as tau-fluvalinate and coumaphos, are very prevalent in honey bee colonies worldwide. However, the endpoints and effects of chronic oral exposure to these compounds remain poorly understood. In this study, we calculated LC50 and LDD50 endpoints for coumaphos and tau-fluvalinate, and then evaluated in vivo and in vitro effects on honey bees using different biomarkers. The LDD50 values for coumaphos were 0.539, and for tau-fluvalinate, they were 12.742 in the spring trial and 8.844 in the autumn trial. Chronic exposure to tau-fluvalinate and coumaphos resulted in significant changes in key biomarkers, indicating potential neurotoxicity, xenobiotic biotransformation, and oxidative stress. The Integrated Biomarker Response was stronger for coumaphos than for tau-fluvalinate, supporting their relative lethality. This study highlights the chronic toxicity of these acaricides and presents the first LDD50 values for tau-fluvalinate and coumaphos in honey bees, providing insights into the risks faced by colonies.

Honey bees and bumble bees may be exposed to pesticides differently when foraging on agricultural areas

In an agricultural environment, where crops are treated with pesticides, bees are likely to be exposed to a range of chemical compounds in a variety of ways. The extent to which different bee species are affected by these chemicals, largely depends on the concentrations and type of exposure. We quantified the presence of selected pesticide compounds in the pollen of two different entomophilous crops; oilseed rape (Brassica napus) and broad bean (Vicia faba). Sampling was performed in 12 sites in Ireland and our results were compared with the pollen loads of honey bees and bumble bees actively foraging on those crops in those same sites. Detections were compound specific, and the timing of pesticide application in relation to sampling likely influenced the final residue contamination levels. Most detections originated from compounds that were not recently applied on the fields, and samples from B. napus fields were more contaminated compared to those from V. faba fields. Crop pollen was contaminated only with fungicides, honey bee pollen loads contained mainly fungicides, while more insecticides were detected in bumble bee pollen loads. The highest number of compounds and most detections were observed in bumble bee pollen loads, where notably, all five neonicotinoids assessed (acetamiprid, clothianidin, imidacloprid, thiacloprid, and thiamethoxam) were detected despite the no recent application of these compounds on the fields where samples were collected. The concentrations of neonicotinoid insecticides were positively correlated with the number of wild plant species present in the bumble bee-collected pollen samples, but this relationship could not be verified for honey bees. The compounds azoxystrobin, boscalid and thiamethoxam formed the most common pesticide combination in pollen. Our results raise concerns about potential long-term bee exposure to multiple residues and question whether honey bees are suitable surrogates for pesticide risk assessments for all bee species.

Contamination of Honeybee (Apis mellifera L.) Royal Jelly by Pesticides and Sample Preparation Methods for Its Determination: A Critical Appraisal

Pesticides can easily enter the food chain, harming bee populations and ecosystems. Exposure of beehive products to various contaminants has been identified as one of the factors contributing to the decline in bee populations, and multiple food alerts have been reported. Despite this fact, royal jelly, a valuable bee product with nutritional and functional properties, has received less attention in this context. Pesticide residues of different chemical class can contaminate royal jelly when foraging bees collect pollen or nectar from pesticide-treated flowers, or in some cases, due to its frequent and inappropriate use in the treatment of mites in beehives. To monitor this issue and also make it more reliable, it is crucial to develop effective sample preparation methods for extracting pesticides from royal jelly for subsequent analysis. In this context, this review provides information about sample preparation methods (solid-phase extraction, solvent extraction, and QuEChERS-quick, easy, cheap, effective, rugged and safe) and analytical methods that have been validated or improved to extract and analyze pesticides, respectively, in royal jelly samples of different origins. Finally, future perspectives are discussed. With this background, we aim to provide data that can guide future research related to this topic.

Enhancing the environmental monitoring of pesticide residues through Apis mellifera colonies: Honey bees versus passive sampling

The use of apicultural matrices for the environmental monitoring of pesticides is a widely employed approach that facilitates to a great extent the sampling procedures. Honey bees are one of the most commonly employed matrices in these studies due to their abundance in the colonies and their direct contact with the beehive and the environment. However, the analysis of this matrix is associated to a lack of representativity of the contaminants accumulated within the beehive, due mainly to the limited number of honey bees that are sampled and analyzed compared to the population in a hive. This small proportion of organisms which are sampled from the colony may lead to underestimations or overestimations of the total pesticide load, depending on the specific individuals that are included in the analysis. In the present work, the passive, non-invasive APIStrip-based sampling approach is compared to active bee sampling with a total of 240 samples taken from 15 apiaries from Austria, Denmark and Greece over a two-month period in 2022. The APIStrips have been found to provide a more comprehensive image of the pesticide residues accumulated in the beehive in terms of number of identified residues and robustness of the results. A total of 74 different pesticide residues were detected: the use of APIStrips allowed to detect 66 pesticides in the three countries, compared to 38 residues in honey bees. The use of APIStrips also resulted in a higher percentage of positive samples (containing at least one pesticide residue). The results provided by the passive sampling approach were also more consistent among the replicates and over time, which reveals an increased sampling robustness.

Quantitation of pesticides in bee bread collected from honey bee colonies in an agricultural environment in Switzerland

Pesticide contamination of bee products is a widespread phenomenon. Due to its composition, bee bread is affected by both lipophilic and hydrophilic substances. As proof of concept of a monitoring campaign and to better understand the extent of contamination, we developed an analytical method based on a modified QuEChERS extraction, with subsequent separation by liquid chromatography and detection by mass spectrometry. This allowed for the quantitation of 51 agricultural- or beekeeping-associated pesticides in bee bread. The workflow was applied to 60 samples taken biweekly throughout spring to autumn 2022 from five colonies at a Swiss apiary in an agricultural area. In total, 30 pesticides were identified (> LOD), among which 26 pesticides were quantitated. The total number of pesticides detected per colony ranged from 11 to 19. The most prevalent substances (> LOQ) were two neonicotinoid insecticides, acetamiprid and thiacloprid (max. 16 μg/kg and 37 μg/kg, respectively); seven fungicides, azoxystrobin (max. 72 μg/kg), boscalid (max. 50 μg/kg), cyprodinil (max. 1965 μg/kg), difenoconazole (max. 73 μg/kg), mandipropamid (max. 33 μg/kg), pyraclostrobin (max. 8 μg/kg) and trifloxystrobin (max. 38 μg/kg); and two herbicides, prosulfocarb (max. 38 μg/kg) and terbuthylazine (max. 26 μg/kg). The study revealed strong variability in pesticide occurrence and concentrations among colonies sampled at the same site and date. The applied biweekly sampling of bee bread from March to August was shown to be reliable in capturing peak contaminations and revealing the onset of certain pesticides in bee bread. The study provides an adequate practical approach for pesticide monitoring campaigns.

Characteristics of contaminants in the polish-origin bee products and cancer risk assessment

The aim of this study was to evaluate the concentration of 5-hydroxymethylfurfural (HMF), furfural, polycyclic aromatic hydrocarbons (PAHs), and pesticide residues, as well as assessment of cancer risk of the Polish-origin bee products. The bee product samples were prepared using a modified QuEChERS method, then PAHs and pesticides were analysed by gas chromatography-mass spectrometry (GC-MS), neonicotinoids by high-performance liquid chromatography with a diode array detector (HPLC-DAD), and HMF and furfural by spectrophotometry (HPLC-UV/Vis). The results showed that the highest furfural content was found in bee bread from the northeast part of Poland; moreover, samples obtained from the same region were also characterized with a higher level of HMF. The total sum of PAHs ranged from 324.0 to 866.4 μg/kg; the highest content of PAH4 (the sum of benzo[a]anthracene, chrysene, benzo[b]fluoranthene and benzo[a]pyrene) was 21.0 μg/kg, but only benzo[a]anthracene and chrysene were detected in the samples. Imidacloprid and acetamiprid were found only in bee bread from the northeast part of Poland, while clothianidin was detected in honey samples. The acceptable cancer risk has been calculated for PAHs due to ingestion of honey, while increasing the risk of cancer was calculated for bee bread and bee pollen. Due to the high concentration of PAHs and excessively high recommended consumption dose, regular consumption of bee bread and pollen may pose a severe threat to human health and should be strictly limited.

Pesticide Residues and Metabolites in Greek Honey and Pollen: Bees and Human Health Risk Assessment

BACKGROUND

Bees encounter a plethora of environmental contaminants during nectar and pollen collection from plants. Consequently, after their entrance into the beehives, the transfer of numerous pollutants to apicultural products is inevitable.

METHODS

In this context, during the period of 2015-2020, 109 samples of honey, pollen, and beebread were sampled and analyzed for the determination of pesticides and their metabolites. More than 130 analytes were investigated in each sample by applying two validated multiresidue methods (HPLC-ESI-MS/MS and GC-MS/MS).

RESULTS

Until the end of 2020, 40 determinations were reported in honey, resulting in a 26% positive to at least one active substance. The concentrations of pesticides ranged from 1.3 ng/g to 785 ng/g honey. For seven active substances in honey and pollen, maximum residue limits (MRLs) exceedances were observed. Coumaphos, imidacloprid, acetamiprid, amitraz metabolites (DMF and DMPF), and tau-fluvalinate were the predominant compounds detected in honey, while several pyrethroids such as λ-cyhalothrin, cypermethrin, and cyfluthrin were also found. Pollen and beebread, as expected, accumulated a higher number of active substances and metabolites (32 in total), exhibiting almost double the number of detections.

CONCLUSIONS

Although the above findings verify the occurrence of numerous pesticide and metabolite residues in both honey and pollen, the human risk assessment in the majority of the cases does not raise any concerns, and the same applies to bee risk assessment.

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.

Comparison of Presowing Wheat Treatments by Low-Temperature Plasma, Electric Field, Cold Hardening, and Action of Tebuconazole-Based Disinfectant

This work compares the presowing treatment of winter wheat seeds with a low-temperature plasma, a constant high-voltage electric field, a plant protection disinfectant, and cold hardening on the resistance of seedlings to freezing and their morphophysiological characteristics at the initial stage of germination. Various treatment combinations were considered, including the effect of the disinfectant jointly with low-temperature plasma treatment. The greatest stimulating effect from the point of view of seedlings’ morphophysiological characteristics was achieved when seeds were cold-hardened. The action of low-temperature plasma is noticeable up to the third day of germination. The treatment with the low-temperature plasma of seeds pretreated and not-pretreated with the disinfectant had a similar effect on the morphophysiological characteristics of seedlings. The plasma treatment and the electric field were combined with each other, i.e., the plasma treatment effects were added to the electric field effects. Resistance to low temperatures was increased with the hardening of seeds treated with the electric field and the disinfectant. Resistance to low temperatures was reduced when treated with the electric field and/or low-temperature plasma after being treated with the disinfectant.

Current Role of Mass Spectrometry in the Determination of Pesticide Residues in Food

The extensive use of pesticides represents a risk to human health. Consequently, legal frameworks have been established to ensure food safety, including control programs for pesticide residues. In this context, the performance of analytical methods acquires special relevance. Such methods are expected to be able to determine the largest number of compounds at trace concentration levels in complex food matrices, which represents a great analytical challenge. Technical advances in mass spectrometry (MS) have led to the development of more efficient analytical methods for the determination of pesticides. This review provides an overview of current analytical strategies applied in pesticide analysis, with a special focus on MS methods. Current targeted MS methods allow the simultaneous determination of hundreds of pesticides, whereas non-targeted MS methods are now applicable to the identification of pesticide metabolites and transformation products. New trends in pesticide analysis are also presented, including approaches for the simultaneous determination of pesticide residues and other food contaminants (i.e., mega-methods), or the recent application of techniques such as ion mobility–mass spectrometry (IM–MS) for this purpose.