Next Article in Journal
Effect of Different Cold Storage Temperatures on the Evolution of Shucking Yield and Quality Properties of Offshore Cultured Japanese Oyster (Magallana gigas) Treated by High Pressure Processing (HPP)
Previous Article in Journal
Technological Characterization of Lactic Acid Bacteria Strains for Potential Use in Cheese Manufacture
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Foods
Volume 12
Issue 6
10.3390/foods12061155
foods-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Review

Glyphosate and Glufosinate Residues in Honey and Other Hive Products

by
Giulia Rampazzo
1,
Teresa Gazzotti
1,2,*,
Elisa Zironi
1 and
Giampiero Pagliuca
1,2
1
Department of Veterinary Medical Science, Alma Mater Studiorum University of Bologna, Via Tolara di Sopra 50, Ozzano dell’Emilia, 40064 Bologna, Italy
2
Health Sciences and Technologies-Interdepartmental Centre for Industrial Research (CIRI-SDV), University of Bologna, Ozzano dell’Emilia, 40064 Bologna, Italy
*
Author to whom correspondence should be addressed.
Foods 2023, 12(6), 1155; https://doi.org/10.3390/foods12061155
Submission received: 31 January 2023 / Revised: 28 February 2023 / Accepted: 7 March 2023 / Published: 9 March 2023
(This article belongs to the Section Food Quality and Safety)
Browse Figures
Versions Notes

Abstract

:
Hive products have numerous beneficial properties; however, the hive’s health is affected by the surrounding environment. The widespread use of herbicides in agriculture, such as glyphosate and glufosinate, has raised alarm among consumers, beekeepers, and environmentalists due to their potential to harm bees and humans through the consumption of bee products. This review aims to provide a comprehensive overview of the presence of glyphosate, glufosinate, and their metabolites in hive products, collecting and comparing available data from peer-reviewed research and surveys conducted across several countries. Moreover, it analyzes and discusses the potential impacts of these substances on human and bee health, analytical aspects, and recent regulatory developments. The data has revealed that these substances can be present in the different matrices tested, but the concentrations found are usually lower than the maximum residue limits set. However, the use of different methodologies with non-uniform analytical performances, together with an incomplete search for regulated analytes, leads to heterogeneity and makes comparisons challenging. In addition to the completion of studies on the toxicology of herbicide active ingredients, further monitoring actions are necessary, harmonizing analytical methodologies and data management procedures.

1. Introduction

A beehive has the potential to accumulate environmental contaminants collected by bees from the surrounding land. In fact, in each hive, several thousand foraging bees visit a thousand flowers each day, resulting in at least a few million interactions daily. Furthermore, the area subject to bee activity has been estimated to be around 7 km2 [1]. Bees not only gather nectar from flowers and pollen and propolis from buds, but they also drink water from the environment and collect suspended particles that settle on plants [2].
The most common environmental contaminants detected in bee products are heavy metals (arsenic, cadmium, mercury, and lead) and certain pesticides (biphenthrin, triadimefon, lambda-cyhalothrin, and chlorpyrifos) [3].
Among plant protection products, herbicides such as glyphosate (Gly) and glufosinate (Glu) are currently a hot topic [4]. In the late 1990s, the introduction of genetically modified crops resistant to these broad-spectrum herbicides led to a significant increase in their usage, with important economic implications [5]. The global market for glyphosate was estimated at $7.6 billion in 2020 and is expected to reach $9.3 billion by 2027. For glufosinate, estimates are $2 billion in 2020, with a projected increase to $3.5 billion by 2027 [6].
The presence of these substances and their metabolites in the environment poses a risk to bees themselves and can also lead to the contamination of hive products.
In recent years, concern about the effects of these substances on both human health and the environment has increased worldwide. In Europe, the two ‘calls for action’ of the Green Deal’s Farm to Fork and Biodiversity strategies aim to reduce the use and risk of pesticides as well as reverse the decline of pollinating insects [7].
Given the controversial evidence regarding the potential health effects of the herbicides under consideration and recognizing that bees and their products are known indicators of environmental poisoning, data on the contamination of these products is still scarce.
To the best of our knowledge, this is the first systematic review that collects and analyzes available information on the contamination of bee products by Gly, Glu, and their metabolites, considering not only scientific publications but also data produced by official controls and honey producers themselves. This study critically compares the collected data with reported analytical performance and legal limits established in various countries, providing a comprehensive, wide-ranging, and up-to-date overview. Furthermore, it highlights the remaining gaps about data collection and evaluation on contamination levels of hive products. Additionally, the review discusses the methods used, the evolution of analytical techniques, and their performances.

2. Methods

A literature search was conducted using various electronic bibliographic databases (e.g., Scopus, PubMed, and Google Scholar) using different keywords such as glyphosate, AMPA (aminomethylphosphonic acid), glufosinate, herbicides, and hive products. The search was further refined by adding honey, beebread, wax, and pollen to the keywords.
Currently, limited information is available on the presence of Gly, AMPA, and Glu in bee products. To have a more complete overview, we consulted institutional databases, reports, and monitoring such as the European Pesticides Database, EFSA’s annual reports on pesticide residues in food, the New Zealand National Chemical Residues Programme Report, the FDA Pesticide Residue Monitoring Database, and local beekeeper association monitoring [8].
This review selected publications based on scientific studies and official surveys examining glyphosate, AMPA, and glufosinate contamination in all hive products and excluded non-peer reviewed works. Additionally, work and monitoring that did not report the total number or a sufficient number of samples (<10) and that did not refer to a validated analytical method were not included. There were no restrictions on the year of publication, author affiliation, or geographic region. The methodological process employed is described in Figure 1.

3. Chemical Properties and Mechanism of Action of Glyphosate and Glufosinate

Gly and Glu are both active ingredients in non-selective herbicides that are used to control weeds on agricultural crops. These substances act on key enzymes in the plant’s metabolic pathway, eventually leading to its death.
Chemically, Gly and Glu belong to the organophosphate category (Figure 2); however, their mechanism of action is different from that of the organophosphate anticholinesterases, and, as a result, their potential effects on human health may be different.
Gly and Glu are anionic polar pesticides, and due to their physicochemical properties, they may pose an analytical challenge [9].
Glyphosate [N-(phosphonomethyl) glycine] is a synthetic active ingredient in so-called glyphosate-based herbicides (GlyBHs). Currently, there are hundreds of GlyBHs sold under assorted brands. Glyphosate is less soluble in its acid form, so GlyBHs are formulated using glyphosate salts, including isopropylamine, ammonium, sodium, potassium, and trimethylsulfonium. In addition, GlyBHs contain polar surfactants, including polyoxyethyleneamide (POEA), sulfuric acid, and phosphoric acid, which enhance the herbicidal action of Gly by increasing its solubility in water and promoting its penetration and absorption by the plant [10]. Gly inhibits the 5-enolpyruvylshikimate-3-phosphate synthase (ESPS) in the shikimic acid pathway, which occurs in plants, bacteria, and fungi but not in animals, affecting the biosynthesis of aromatic amino acids, vitamins, and many secondary plant metabolites [11].
Glufosinate, marked worldwide under different commercial brands, is the active ingredient of many non-selective herbicides. It is a racemic mixture of two D and L enantiomers [DL-phosphinothricin or 2-amino-4-(hydroxymethylphosphoryl)butanoic acid], often referred to as glufosinate-ammonium because the ammonium-salt formulations are the most widely used. Glufosinate-based herbicides (GluBHs) contain adjuvants that improve their phytotoxicity, such as ammonium-sulfate and surfactants to enhance wettability and herbicide penetration.
Some species of Streptomyces can produce a tripeptide called bialaphos through fermentation. Upon penetrating the plant, it is hydrolyzed to produce the L-enantiomer of glufosinate (L-phosphinothricin) which is herbicidally active [12]. Once inside the plant cell, Glu acts as a glutamate analogue towards the enzyme glutamine synthetase. This irreversible inhibition of the condensation reaction between glutamate and ammonia causes the latter to accumulate inside the cells. This accumulation leads to the disintegration of the chloroplasts and therefore the death of the plant due to the inhibition of photosynthesis [12].

4. Degradation of Glyphosate and Glufosinate

A significant amount of Gly is not taken up by plants and is instead dispersed into the environment, where it undergoes rapid degradation through abiotic and biotic processes such as photolysis, thermolysis, and biodegradation. The degradation time (DT50) can vary widely depending on environmental conditions, with soil studies reporting DT50 values ranging from 1 to 130 days [13]. The main Gly metabolite is AMPA, which is more persistent and causes secondary contamination in the environment [14]. AMPA is often detected in surface water, sediment, and groundwater [15]; soil studies report AMPA DT50 values ranging from 76 to 240 days [13]. Other known Gly metabolites, such as HMPA [(hydroxymethyl)phosphonic acid], N-acetyl-glyphosate [N-acetyl-N-(phosphonomethyl)glycine], and N-acetyl-AMPA [(acetamidomethyl)phosphonic acid], are currently understudied.
Glu is also rapidly degraded by plants and soil bacteria through oxidation, transamination, and acetylation reactions [12]. Laboratory studies on the rate of degradation in soil have reported DT50 values from 6 to 11 days [16]. Its main metabolite is MPP [3-(hydroxy(methyl)phosphinoyl) propionic acid], which may undergo further degradation to MPA (2-methylphosphinico-acetic acid) and N-acetyl-glufosinate. MPP and MPA are moderately persistent, with soil DT50 values of 13–20 days and 17–18 days, respectively [16].

5. Glyphosate and Glufosinate Effects on Honeybees’ Health

Recent evidence suggests that honeybee populations are declining or suffering from Colony Collapse Disorder (CCD), a phenomenon in which most worker bees abandon the hive, leaving behind the queen, nurse bees, and larvae. Among the causes of CCD, herbicide use may have adverse effects on bees not only directly but also indirectly by reducing the availability of nectar- and pollen-producing plants [17]. The impact of these polar pesticides on non-target organisms is still unclear and controversial; a recent review examined the effects of Gly on bee mortality through a meta-analysis of articles published between 1945 and 2020 [2]. The analysis showed that Gly and GlyBHs exposure may have toxic, even lethal, effects on bees, including impacts on cognitive abilities and sleep. Both adult bees and larvae were found to be sensitive, and chronic exposure was found to be the most harmful [2]. The IUPAC Pesticides Properties Data Base (PPDP) reports the following Gly ecotoxicity values for honeybees: contact acute LD₅₀ > 100 μg bee⁻1; oral acute LD₅₀ 104 μg bee⁻1.
Although limited information is available on the toxic effects of Glu, it appears to have minor toxicity due to its rapid degradation in the environment. The PPDP also reports the following Glu-ammonium ecotoxicity values for honeybees: contact acute LD₅₀ > 345 μg bee⁻1; oral acute LD₅₀ 600 μg bee⁻1. Ecological risk assessments for pesticide registration should consider the potential risks to bees and other pollinating insects from the application of high concentrations of herbicides to crops that attract them. Label use restrictions should be implemented to reduce bee exposure [18,19].

6. Regulatory Agencies’ Assessment on Health Effects in Humans and Regulatory Developments

The toxicity of Gly is still a topic of debate. Recently, EFSA proposed an acute reference dose (ARfD) of 500 µg/kg of body weight [20]. Exposure to Gly may cause general human health problems, such as bladder and liver toxicity, severe eye damage, and endocrine issues [21,22]. Over the past few years, there has been significant discussion regarding Gly’s potential carcinogenicity. In 2015, the International Agency for Research on Cancer (IARC) declared Gly as “probably carcinogenic to humans” due to limited evidence of carcinogenicity in humans and sufficient evidence of carcinogenicity in experimental animals [23]. This sparked widespread concern and debate about its safety. In contrast, other regulatory agencies, such as the European Food Safety Authority (EFSA) [20] and the US Environmental Protection Agency (EPA), concluded that Gly is unlikely to pose a cancer risk to humans [24]. In 2017, the EU renewed the license for the use of Gly for five years, with some restrictions on its use; however, the renewal was controversial and opposed by some member states and environmental groups. Supporters of the renewal argue that the chemical is essential for modern farming, and that without it, food production would suffer. Opponents of the renewal maintained that Gly is dangerous and that alternatives should be explored [25]. In December 2022, the EU extended the approval of Gly by one year to allow EFSA sufficient time to conclude its new peer review [26].
Glu can be harmful to humans when ingested or when it comes in contact with the skin. The World Health Organization (WHO) classifies Glu is as a category III compound, meaning that it is “moderately hazardous” and may cause “temporary incapacitation or possible residual injury”. In humans, Glu can cause symptoms such as eye, skin, and lung irritation. Ingestion of Glu can lead to nausea, vomiting, and diarrhea. In some cases, it may also cause tremors, convulsions, and difficulty breathing [27]. According to the IUPAC Pesticides Properties Data Base (PPDP), Glu is a possible toxicant for the kidneys, bladder, blood, and lungs [21]. While Glu was authorized for use in Europe until 2018, its registration was not renewed by the European Commission due to concerns about its toxicity [12,28]; however, Glu continues to be widely used in the United States, South America, and other parts of the world, both on crops and in non-agricultural areas [12].
To protect consumer health, the European Union has set maximum residue limits (MRLs) for pesticides in honey and other apiculture products; however, Regulation (EU) 2018/62 [29] clarifies that MRLs for honey do not apply to other apiculture products due to their different chemical characteristics. The MRL for glyphosate is set at 50 µg/kg according to Commission Regulation (EU) No 2013/293 [30].
For glufosinate [sum of glufosinate isomers, its salts, and its metabolites (MPP and N-acetyl-glufosinate)] Commission Regulation (EU) 2016/1002 set the MRL at 50 µg/kg [31]. Similar limits have been adopted in other countries. In Japan, the MRL for the sum of glyphosate and N-acetyl-glyphosate calculated as glyphosate is set at 50 µg kg for honey (including royal-jelly), with no limits set for other metabolites or for glufosinate [32]. In Australia and New Zealand, the MRL for the sum of glyphosate, N-acetyl-glyphosate, and AMPA, expressed as glyphosate in honey, is 200 µg/kg [33], and no limit has been set for glufosinate. The US and Canada have not established an MRL for glyphosate or glufosinate in honey [34]. Table 1 shows the different MRLs set for Gly and Glu in various countries.

7. Analytical Methods for the Determination of Glyphosate, Glufosinate, and Their Metabolites in Honey and Other Hive Products

The determination of Gly, Glu, and their metabolites in honey and other hive products is a challenging task; this is due to their small molecular size and physicochemical properties, such as high polarity, lack of ultraviolet absorption, high solubility in water, low ionization, and low volatility. Furthermore, the high solubility in water and small size of these compounds make selective extraction difficult, resulting in a strong matrix effect [35]. Additionally, the high concentration of sugars can lead to instrument contamination when combined with a non-selective extraction.
Table 2 presents a summary of the main analytical methods used to date for the detection of Gly, AMPA, and Glu in honey, bee bread, and wax, along with their corresponding limits of detection (LOD) and quantification (LOQ). Cases where derivatization techniques were utilized are also included. Upon reviewing the research studies, it is evident that they are all quite recent, having been published within the last five years, except for Guo et al. [35], which dates to 2014. This may be attributed to the increasing attention given to these pesticides as well as new developments in the analytical field that have addressed some of the challenges mentioned previously. The techniques listed in Table 2 are highly diverse and range from extremely rapid enzyme screening methods to sophisticated instrumentation such as HRMS (high-resolution mass spectrometry).
From Table 2, the main methods used for the analysis of these pesticides involve the use of liquid chromatography combined with mass spectrometry (MS) and, in only one case, coupled with a fluorescence detector (FLD) [41].
Only in three studies was Gly detected in honey by enzyme-linked immunosorbent assay (ELISA). However, the type of kit used (Abraxis Glyphosate Plate Assay Kit 500086) was designed to analyze glyphosate in water (groundwater, surface water, well water), therefore it had to be adapted to different matrices, including honey [35,44,45].
As far as the chromatographic approach is concerned, a few years ago the use of traditional reversed-phase liquid chromatography did not provide optimal retention of small polar analytes and often required the use of derivatization. Derivatization analysis permits good separation even on reverse phase columns, but presents problems related to contamination of both columns and detectors by the derivatizing agents’ byproducts. The most commonly used derivatizing agent is FMOC-Cl (9-fluorenylmethoxycarbonyl chloride) [34,37]; an author proposes dansyl cloride (5-(dimethylamino) naphthalene-1-sulfonyl chloride) as an alternative, reporting less interference [38]. Making these pesticides fluorescent is necessary when using fluorescence detectors. In the work of de Souza et al., this step was performed by post-column derivatization with o-phthalaldehyde (OPA) [41].
More recently, analysis in liquid chromatography without derivatization has been made possible by the development of columns based on different approaches, often using multiple retention mechanisms such as hydrophilic interaction liquid chromatography (HILIC), weak anion exchange (WAX), weak cation exchange (WCX), and porous graphitic carbon stationary phases. However, these approaches have only recently been improved, resulting in adequate robustness for routine analytical use.
Ion chromatography (IC), a High-Performance Liquid Chromatography of small charged solutes, is another potential option, although it is not yet widely used.
As shown in Table 2, the use of tandem mass spectrometry (MS/MS) systems coupled with chromatography is prevalent among the detectors used for the determination of herbicides in hive products. These instruments can provide high performance, meeting all the sensitivity and selectivity requirements needed for this type of analysis. The use of high-resolution mass spectrometry (HRMS) can further enhance these performances.
The “Quick Polar Pesticides Method” (QuPPE), developed and regularly updated by the EU Reference Laboratories for Residues of Pesticide, enables the analysis of a selection of highly polar pesticides (including Gly, Glu, and various metabolites) in foods of plant origin and honey. This method involves extraction with acidified methanol and the use of LC- or IC-MS/MS techniques to analyze multiple combinations of pesticides simultaneously [49].
The quality of the exposure assessment is largely dependent on the quantity and accuracy of the data available and how it is utilized.
The risk analysis is frequently challenged by datasets composed of large amounts of left-censored values, which are difficult to analyze statistically. In particular, this refers to chemical contaminant data reported to be below the limit of detection (LOD) or limit of quantification (LOQ). Left-censoring indicates that there is a limit of contamination below which values cannot be accurately determined. The substitution method should be used to deal with left-censored values, which involves replacing non-detects with either zero or LOD or LOQ depending on the lower and upper bound scenarios [50]. This approach was used in only one study examining glyphosate contamination in honey [44].
As reported in Table 2, the values of LOD and LOQ can vary greatly depending on the method used: ELISA methods show LOQs ranging from 0.4 to 15 µg/kg, LC-MS/MS methods reported limits between 1 and 50 µg/kg, and IC-HRMS range from 5 to 9.26 µg/kg.
The lack of reporting of the LOD in the methods being examined, as well as the LOQ values being either very low or corresponding to the MRL set by the EU, affects the values of left-censored and quantifiable samples from the different monitoring shown in Table 3.

8. Reported Levels of Herbicide Contamination in Hive Products

In recent years, thanks to the development of specific analytical methods, some studies and monitoring have been conducted on the presence of herbicide residues (in particular Gly, AMPA, and Glu) in hive products.
Some of these investigations looked at factors that may influence the level of contamination in these matrices beyond the amount of herbicide used and the frequency of its application. The environmental conditions can also play a role in the herbicide contamination of honey; for example, rainfall can wash herbicides off plants and into nearby water sources, where they can eventually be taken up by bees. Additionally, wind can carry herbicides further afield, potentially increasing their presence in honey.
The results of a survey conducted in New Zealand in 2017/2018 [51] suggest that inadvertent exposure of honeybees to Gly from its approved use in agriculture and on pastures is the most likely source of its residues in honey. Therefore, beekeepers have no way to prevent bees from gathering nectar and pollen from plants sprayed with this herbicide. Clover and pasture, or multifloral/blend honeys, were found to have a higher frequency of Gly residues.
The research results from northern Italy indicate that Gly is present in beehives and their products throughout the year, with concentrations varying by season, and its presence appears to be increasing over time. Additionally, the herbicide was detected in pollen collected at an elevation of 850 m above sea level. This discovery challenges the assumption that glyphosate in hives is due to drift from nearby agricultural areas and proves that even remote areas are subject to contamination [8]. On the other hand, AMPA is rarely found in hives and hive products, indicating that the contaminant is not being collected from water, where the concentration of the metabolite is much higher than the parent molecule [8].
The results of monitoring for Gly, AMPA, and Glu in honey, beebread, and beeswax samples are summarized in Table 3, which includes data from scientific articles in the literature, national monitoring by control authorities [51,55,56,57], and monitoring by beekeepers’ associations [8], totaling 20 studies.
Table 3 presents the total number of samples analyzed per matrix, the number and percentage of left-censored and quantifiable samples, along with their relative contamination range, mean, and median (when indicated). The outcomes are listed in chronological order, starting with the most recent results.
Regarding honey, it appears to be the most extensively monitored matrix, with 20 studies conducted. A total of 1965 honey samples were analyzed, and all were investigated for the presence of Gly. It was found in 625 samples (32% of all samples), with contamination ranging from 2.0 µg/kg up to 5500 µg/kg, with maximum levels of 3500 µg/kg in Pakistan [53] and 5500 µg/kg in Europe [48]. Nevertheless, there is very little consistent data available, so drawing conclusions about the actual contamination and factors that may influence the presence of this pesticide is extremely risky. The reviewed documents rarely compare contamination levels with MRLs set by different countries. A comparison of the few available mean or median values shows that, in most cases, the reported concentration is below the MRL [34,37,39,46,48]. However, in other cases [52,53], it is well above, with averages 20 or 40 times higher than any limit.
In nine studies, concentrations of AMPA ranging from 1.9 µg/kg to 100 µg/kg were detected in 208 (44%) of the 471 honey samples tested.
It is noteworthy that Thompson et al. [34] found the highest rate of samples testing positive for both Gly (99%) and AMPA (99%). A similar figure was recorded in a study conducted in Switzerland [46], where the percentage of quantifiable samples for Gly was 94%. This high rate of quantifiable samples may be due to the low declared LOQ value of 1 µg/kg.
If monitoring and scientific research related to Gly contamination in honey are limited, those related to Glu are even rarer; in fact, Glu was only considered in four studies, with a total of 322 analyzed samples. It was found in only one study by Thompson et al. in 2019 [34] in 125 samples (39%) of Canadian honey, with contamination ranging from 1 µg/kg up to 33 µg/kg. The scarcity of data on Glu contamination in honey could be due to several factors, such as its lower use compared with Gly, its rapid degradation in soil, and the non-renewal of registration in Europe since 2018. Furthermore, data on the sum of Glu and its main metabolites, as required by the EU MRL, has never been reported. In particular, the presence of MPP was never investigated in honey. Regarding N-acetyl glyphosate and N-acetyl glufosinate, only a single sample of honey has been reported in the EU Pesticides Database with unquantifiable values [52].
Figure 3 illustrates the honey samples that were tested for Gly in various parts of the world, with the majority (59%) being tested in Europe, followed by Oceania (22%), and North America (15%). The European results are quite varied, with some surveys [52] showing mean and median values that are much higher than the EU MRL, while others have no quantifiable samples [43,54,55,56,57]. In Italy [8,38,43,54], where more research has been conducted on these analytes, the data is very inconsistent. As already mentioned, these variabilities could be due to different analytical performances.
Among other hive products, two studies analyzed bee-bread samples and found that 72% (119 samples) of the 165 samples tested were contaminated with Gly, with concentrations ranging from 10 to 700 µg/kg. AMPA was measured in beebread only by El Agreibi et al., with contamination levels ranging from 10 µg/kg to 250 µg/kg and a quantifiable sample percentage of 26% [39].
This research was the only one to analyze the presence of Gly and AMPA in beeswax. Out of 100 samples, 32% tested positive for Gly, with levels ranging from 10 to 320 µg/kg. No samples were found to contain quantifiable amounts of AMPA [39]. The results of a recent study [58] showed that all 120 pollen samples tested contained Gly, with levels ranging from 5.07 µg/kg to 7.29 µg/kg; however, these findings were not included in those processed because they were reported in a preliminary report that had not undergone peer review. No other pollen contamination data were found.
No studies were found on the levels of Gly or Glu and their metabolites in other hive products, such as royal jelly or propolis. Additionally, the presence of Glu was not investigated in any of the matrices reported above.

9. Conclusions

Active substances in herbicides can accumulate in the environment and be transferred to bees and their hive products. This could pose a hazard to human health if not monitored and controlled efficiently. Therefore, monitoring activities that provide accurate and comparable data can help to evaluate product safety and quality, and to take preventive measures if necessary.
The raw data, which would have provided a more precise understanding of the degree of contamination and allowed for the identification of samples that did not meet the MRL, was not available in most of the sources reviewed. As a result, the scarcity of data on the contamination levels of the herbicides in question makes an accurate risk assessment difficult. While some studies indicate elevated contamination levels, most authors agree that the risk to consumers is relatively low when hive products are consumed. However, evidence suggests that survey and research programs should continue to conduct monitoring activities.
Additionally, the potential toxicity of individual components of herbicides is not fully understood, and there is limited knowledge of the possible synergistic effects of mixtures of their residues. Moreover, it is noteworthy that the monitoring conducted rarely examined all the regulated substances simultaneously.
Harmonizing analytical performance and data processing is also crucial, and the development of new analytical techniques has improved sensitivity and reproducibility. Representative data are required for an accurate dietary exposure/risk assessment, and proper management of non-quantified (<LOQ) and non-detected (<LOD) samples is crucial. The decision on what value to assign to these results can influence their correct interpretation.
Finally, it would be desirable for the raw data from the various surveys to be made freely available so that it can be reprocessed and reanalyzed. Regulatory bodies, researchers, and beekeepers should continue to work together to monitor and limit the use of herbicides and promote sustainable beekeeping practices to ensure the safety of hive products and the environment.

Author Contributions

All authors contributed equally to the review. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Data Availability Statement

No new data were created in this study. Data sharing is not applicable to this article.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. de Oliveira, R.C.; do Nascimento Queiroz, S.C.; da Luz CF, P.; Porto, R.S.; Rath, S. Bee Pollen as a Bioindicator of Environmental Pesticide Contamination. Chemosphere 2016, 163, 525–534. [Google Scholar] [CrossRef] [PubMed]
  2. Battisti, L.; Potrich, M.; Sampaio, A.R.; de Castilhos Ghisi, N.; Costa-Maia, F.M.; Abati, R.; dos Reis Martinez, C.B.; Sofia, S.H. Is Glyphosate Toxic to Bees? A Meta-Analytical Review. Sci. Total Environ. 2021, 767, 145397. [Google Scholar] [CrossRef] [PubMed]
  3. Sharma, A.; Pant, K.; Brar, D.S.; Thakur, A.; Nanda, V. A Review on Api-Products: Current Scenario of Potential Contaminants and Their Food Safety Concerns. Food Control 2023, 145, 109499. [Google Scholar] [CrossRef]
  4. Lajmanovich, R.C.; Attademo, A.M.; Lener, G.; Cuzziol Boccioni, A.P.; Peltzer, P.M.; Martinuzzi, C.S.; Demonte, L.D.; Repetti, M.R. Glyphosate and Glufosinate Ammonium, Herbicides Commonly Used on Genetically Modified Crops, and Their Interaction with Microplastics: Ecotoxicity in Anuran Tadpoles. Sci. Total Environ. 2022, 804, 150177. [Google Scholar] [CrossRef]
  5. Dill, G.M. Glyphosate-Resistant Crops: History, Status and Future. Pest Manag. Sci. 2005, 61, 219–224. [Google Scholar] [CrossRef]
  6. Marketresearch. Available online: https://www.marketresearch.com/Global-Industry-Analysts-v1039/Glyphosate-32281218/ (accessed on 18 January 2023).
  7. More, S.J.; Auteri, D.; Rortais, A.; Pagani, S. EFSA Is Working to Protect Bees and Shape the Future of Environmental Risk Assessment. EFSA J. 2021, 19, e190101. [Google Scholar] [CrossRef] [PubMed]
  8. Bosco, L.; Bergero, M.; Panella, F.; Oldani, S.; Concari, C. Dossier | 2017–2019 Environmental Bio-Monitoring with Bees. Available online: https://www.lapisonline.it/wps/wp-content/uploads/2021/09/ENGL_dossier_02_2019_biomonitorag.pdf (accessed on 30 January 2023).
  9. Verdini, E.; Pecorelli, I. The Current Status of Analytical Methods Applied to the Determination of Polar Pesticides in Food of Animal Origin: A Brief Review. Foods 2022, 11, 1527. [Google Scholar] [CrossRef]
  10. Soares, D.; Silva, L.; Duarte, S.; Pena, A.; Pereira, A. Glyphosate Use, Toxicity and Occurrence in Food. Foods 2021, 10, 2785. [Google Scholar] [CrossRef]
  11. Dill, G.M.; Sammons, R.D.; Feng, P.C.; Kohn, F.; Kretzmer, K.; Mehrsheikh, A.; Bleeke, M.; Honegger, J.L.; Farmer, D.; Wright, D. Glyphosate: Discovery, Development, Applications, and Properties. In Glyphosate Resistance in Crops and Weeds: History, Development, and Management; John Wiley & Sons, Inc.: Hoboken, NJ, USA, 2010; pp. 1–33. [Google Scholar] [CrossRef]
  12. Takano, H.K.; Dayan, F.E. Glufosinate-ammonium: A Review of the Current State of Knowledge. Pest Manag. Sci. 2020, 76, 3911–3925. [Google Scholar] [CrossRef]
  13. European Commission Review Report for the Active Substance Glyphosate. 29 June 2001. Available online: https://ec.europa.eu/food/fs/ph_ps/pro/eva/existing/list1_glyphosate_en.pdf (accessed on 18 January 2023).
  14. Singh, S.; Kumar, V.; Gill, J.P.K.; Datta, S.; Singh, S.; Dhaka, V.; Kapoor, D.; Wani, A.B.; Dhanjal, D.S.; Kumar, M. Herbicide Glyphosate: Toxicity and Microbial Degradation. Int. J. Environ. Res. Public Health 2020, 17, 7519. [Google Scholar] [CrossRef]
  15. Ojelade, B.S.; Durowoju, O.S.; Adesoye, P.O.; Gibb, S.W.; Ekosse, G.-I. Review of Glyphosate-Based Herbicide and Aminomethylphosphonic Acid (AMPA): Environmental and Health Impacts. Appl. Sci. 2022, 12, 8789. [Google Scholar] [CrossRef]
  16. European Food Safety Authority (EFSA). Conclusion Regarding the Peer Review of the Pesticide Risk Assessment of the Active Substance Glufosinate. EFSA J. 2005, 27, 1–81. [Google Scholar] [CrossRef]
  17. Johnson, R.M. Honeybee Toxicology. Annu. Rev. Entomol. 2015, 60, 415–434. [Google Scholar] [CrossRef] [Green Version]
  18. European Food Safety Authority (EFSA). Advancing Environmental Risk Assessment for Bees and Other Insect Pollinators. Available online: https://www.efsa.europa.eu/en/events/advancing-environmental-risk-assessment-bees-and-other-insect-pollinators (accessed on 18 January 2023).
  19. U.S. Environmental Protection Agency. U.S. Environmental Protection Agency’s Policy to Mitigate the Acute Risk to Bees from Pesticide Products. Available online: https://www.regulations.gov/document/EPA-HQ-OPP-2014-0818-0477 (accessed on 30 January 2023).
  20. European Food Safety Authority. EFSA Explains Risk Assessment: Glyphosate. Available online: https://www.efsa.europa.eu/en/corporate/pub/glyphosate151112 (accessed on 30 January 2023).
  21. IUPAC Pesticides Properties DataBase. Available online: http://sitem.herts.ac.uk/aeru/iupac/index.htm (accessed on 18 January 2023).
  22. FAO/WHO. Pesticide Residues in Food 2016; FAO/WHO: Rome, Italy, 2016. Available online: https://www.fao.org/3/I6926EN/bookmarks-i6926en.pdf (accessed on 30 January 2023).
  23. International Agency for Research on Cancer, World Health Organization. Some Organophosphate Insecticides and Herbicides. Lyon, France, 2017. Available online: https://www.iarc.who.int/news-events/iarc-monographs-volume-112-some-organophosphate-insecticides-and-herbicides-3/ (accessed on 30 January 2023).
  24. Benbrook, C.M. How Did the US EPA and IARC Reach Diametrically Opposed Conclusions on the Genotoxicity of Glyphosate-Based Herbicides? Environ. Sci. Eur. 2019, 31, 2. [Google Scholar] [CrossRef]
  25. European Parliament. Renewing the Approval of the Active Substance Glyphosate. Available online: https://www.europarl.europa.eu/doceo/document/TA-8-2017-0395_EN.pdf (accessed on 30 January 2023).
  26. European Commission. Extension of the Approval Period of Glyphosate. Available online: https://food.ec.europa.eu/plants/pesticides/approval-active-substances/renewal-approval/glyphosate_en (accessed on 12 January 2023).
  27. Donthi, D.N.R.; Kumar, A.D.D. Glufosinate Ammonium An Overview, Pesticide Action Network, India. 2022. Available online: https://pan-india.org/wp-content/uploads/2022/12/Glufosinate-Ammonium-An-overview_PAN-India_Dec2022.pdf (accessed on 30 January 2023).
  28. Commission Regulation (EU) 2020/1068 of 15 May 2020 Amending Annexes I and V to Regulation (EU) No 649/2012 of the European Parliament and of the Council Concerning the Export and Import of Hazardous Chemicals. Available online: https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32020R1068&from=EN (accessed on 23 February 2023).
  29. Commission Regulation (EU) 2018/62 of 17 January 2018 Replacing Annex I to Regulation (EC) No 396/2005 of the European Parliament and of the Council. Available online: https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32018R0062&from=EN (accessed on 24 February 2023).
  30. Commission Regulation (EU) No 293/2013 of 20 March 2013 Amending Annexes II and III to Regulation (EC) No 396/2005 of the European Parliament and of the Council as Regards Maximum Residue Levels for Emamectin Benzoate, Etofenprox, Etoxazole, Flutriafol, Glyphosate, Phosmet, Pyraclostrobin, Spinosad and Spirotetramat in or on Certain Products. Available online: https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32013R0293&from=EN (accessed on 23 February 2023).
  31. Commission Regulation (EU) 2016/1002 of 17 June 2016 Amending Annexes II, III and V to Regulation (EC) No 396/2005 of the European Parliament and of the Council as Regards Maximum Residue Levels for AMTT, Diquat, Dodine, Glufosinate and Tritosulfuron in or on Certain Products. Available online: https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32016R1002&from=EN (accessed on 23 February 2023).
  32. Japan Food Chemical Research Foundation. Search Engine for MRLs. Available online: http://db.ffcr.or.jp/front/food_group_detail?id=20600 (accessed on 18 January 2023).
  33. Australia New Zealand Food Standards Code–Schedule 20–Maximum Residue Limits. Available online: https://www.legislation.gov.au/Series/F2015L00468 (accessed on 18 January 2023).
  34. Thompson, T.S.; van den Heever, J.P.; Limanowka, R.E. Determination of Glyphosate, AMPA, and Glufosinate in Honey by Online Solid-Phase Extraction-Liquid Chromatography-Tandem Mass Spectrometry. Food Addit. Contam. Part A 2019, 36, 434–446. [Google Scholar] [CrossRef] [PubMed]
  35. Emily Guo, F.R. Survey of Glyphosate Residues in Honey, Corn and Soy Products. J. Environ. Anal. Toxicol. 2014, 5, 1–8. [Google Scholar] [CrossRef]
  36. Medici, S.K.; Maggi, M.D.; Galetto, L.; del Rosario Iglesias, M.; Sarlo, E.G.; Recavarren, M.I.; Salar, P.E.; Eguaras, M.J. Influence of the Agricultural Landscape Surrounding Apis Mellifera Colonies on the Presence of Pesticides in Honey. Apidologie 2022, 53, 21. [Google Scholar] [CrossRef]
  37. Bergero, M.; Bosco, L.; Giacomelli, A.; Angelozzi, G.; Perugini, M.; Merola, C. Agrochemical Contamination of Honey and Bee Bread Collected in the Piedmont Region, Italy. Environments 2021, 8, 62. [Google Scholar] [CrossRef]
  38. Jansons, M.; Pugajeva, I.; Bartkevics, V.; Karkee, H.B. LC-MS/MS Characterisation and Determination of Dansyl Chloride Derivatised Glyphosate, Aminomethylphosphonic Acid (AMPA), and Glufosinate in Foods of Plant and Animal Origin. J. Chromatogr. B 2021, 1177, 122779. [Google Scholar] [CrossRef]
  39. El Agrebi, N.; Tosi, S.; Wilmart, O.; Scippo, M.-L.; de Graaf, D.C.; Saegerman, C. Honeybee and Consumer’s Exposure and Risk Characterisation to Glyphosate-Based Herbicide (GBH) and Its Degradation Product (AMPA): Residues in Beebread, Wax, and Honey. Sci. Total Environ. 2020, 704, 135312. [Google Scholar] [CrossRef]
  40. Raimets, R.; Bontšutšnaja, A.; Bartkevics, V.; Pugajeva, I.; Kaart, T.; Puusepp, L.; Pihlik, P.; Keres, I.; Viinalass, H.; Mänd, M.; et al. Pesticide Residues in Beehive Matrices Are Dependent on Collection Time and Matrix Type but Independent of Proportion of Foraged Oilseed Rape and Agricultural Land in Foraging Territory. Chemosphere 2020, 238, 124555. [Google Scholar] [CrossRef] [PubMed]
  41. de Souza, A.P.F.; Rodrigues, N.R.; Reyes, F.G.R. Glyphosate and Aminomethylphosphonic Acid (AMPA) Residues in Brazilian Honey. Food Addit. Contam. Part B 2021, 14, 40–47. [Google Scholar] [CrossRef] [PubMed]
  42. Chiesa, L.M.; Nobile, M.; Panseri, S.; Arioli, F. Detection of Glyphosate and Its Metabolites in Food of Animal Origin Based on Ion-Chromatography-High Resolution Mass Spectrometry (IC-HRMS). Food Addit. Contam. Part A 2019, 36, 592–600. [Google Scholar] [CrossRef] [PubMed]
  43. Pareja, L.; Jesús, F.; Heinzen, H.; Hernando, M.D.; Rajski, Ł.; Fernández-Alba, A.R. Evaluation of Glyphosate and AMPA in Honey by Water Extraction Followed by Ion Chromatography Mass Spectrometry. A Pilot Monitoring Study. Anal. Methods 2019, 11, 2123–2128. [Google Scholar] [CrossRef]
  44. Berg, C.J.; King, H.P.; Delenstarr, G.; Kumar, R.; Rubio, F.; Glaze, T. Glyphosate Residue Concentrations in Honey Attributed through Geospatial Analysis to Proximity of Large-Scale Agriculture and Transfer off-Site by Bees. PLoS ONE 2018, 13, e0198876. [Google Scholar] [CrossRef]
  45. John, J.; Liu, H. Glyphosate Monitoring in Water, Foods, and Urine Reveals an Association between Urinary Glyphosate and Tea Drinking: A Pilot Study. Int. J. Environ. Health Eng. 2018, 7, 2. [Google Scholar] [CrossRef]
  46. Zoller, O.; Rhyn, P.; Rupp, H.; Zarn, J.A.; Geiser, C. Glyphosate Residues in Swiss Market Foods: Monitoring and Risk Evaluation. Food Addit. Contam. Part B 2018, 11, 83–91. [Google Scholar] [CrossRef]
  47. Chamkasem, N.; Vargo, J. Development and Independent Laboratory Validation of an Analytical Method for the Direct Determination of Glyphosate, Glufosinate, and Aminomethylphosphonic Acid in Honey by Liquid Chromatography/Tandem Mass Spectrometry. JRS 2017, 5, 1–9. [Google Scholar] [CrossRef]
  48. Karise, R.; Raimets, R.; Bartkevics, V.; Pugajeva, I.; Pihlik, P.; Keres, I.; Williams, I.H.; Viinalass, H.; Mänd, M. Are Pesticide Residues in Honey Related to Oilseed Rape Treatments? Chemosphere 2017, 188, 389–396. [Google Scholar] [CrossRef]
  49. Anastassiades, M.; Mack, D.; Wildgrube, C.; Barth, A.; Sigalov, I.; Görlich, S.; Dörk, D.; Cerchia, G. Quick Method for the Analysis of Highly Polar Pesticides in Food Involving Extraction with Acidified Methanol and LC- or IC-MS/MS Measurement in Food of Plant Origin (QuPPe-PO-Method). Available online: https://www.eurl-pesticides.eu/docs/public/tmplt_article.asp?LabID=200&CntID=1115&Theme_ID=1&Pdf=False&Lang=EN (accessed on 18 January 2023).
  50. European Food Safety Authority. Management of Left-censored Data in Dietary Exposure Assessment of Chemical Substances. EFSA J. 2010, 8, 1557. [Google Scholar] [CrossRef] [Green Version]
  51. New Zealand National Chemical Residues Programme Report Results for Agricultural Compound Residues in Honey. Available online: https://www.mpi.govt.nz/dmsdocument/44002-Results-for-1-July-2019-30-June-2020 (accessed on 30 January 2023).
  52. EU Pesticides Database. Available online: https://food.ec.europa.eu/plants/pesticides/eu-pesticides-database_en (accessed on 30 January 2023).
  53. Yaqub, G.; Khalid, M.; Ikram, A.; Sohail, A. Monitoring and Risk Assessment Due to Presence of Metals and Pesticides Residues in Honey Samples from the Major Honey Producing Forest Belts and Different Brands. Food Sci. Technol. 2020, 40, 331–335. [Google Scholar] [CrossRef]
  54. Panseri, S.; Bonerba, E.; Nobile, M.; Di Cesare, F.; Mosconi, G.; Cecati, F.; Arioli, F.; Tantillo, G.; Chiesa, L. Pesticides and Environmental Contaminants in Organic Honeys According to Their Different Productive Areas toward Food Safety Protection. Foods 2020, 9, 1863. [Google Scholar] [CrossRef] [PubMed]
  55. European Food Safety Authority (EFSA); Carrasco Cabrera, L.; Medina Pastor, P. The 2019 European Union Report on Pesticide Residues in Food. EFSA J. 2021, 19, e06491. [Google Scholar] [CrossRef] [PubMed]
  56. European Food Safety Authority (EFSA); Medina-Pastor, P.; Triacchini, G. The 2018 European Union Report on Pesticide Residues in Food. EFSA J. 2020, 18, e06057. [Google Scholar] [CrossRef] [Green Version]
  57. European Food Safety Authority (EFSA). The 2017 European Union Report on Pesticide Residues in Food. EFSA J. 2019, 17, e05743. [Google Scholar] [CrossRef] [Green Version]
  58. Ruiz-Toledo, J.; Sánchez, D. Risk Characterization to Glyphosate in Honeybee and Consumer’s Exposed to Honeybee-Collected Pollen in Southeastern Mexico. 2022. Available online: https://europepmc.org/article/PPR/PPR523428 (accessed on 18 January 2023). [CrossRef]
Foods 12 01155 g001 550
Figure 1. Methodology flowsheet.
Figure 1. Methodology flowsheet.
Foods 12 01155 g001
Foods 12 01155 g002 550
Figure 2. Glyphosate, glufosinate and metabolites chemical structures.
Figure 2. Glyphosate, glufosinate and metabolites chemical structures.
Foods 12 01155 g002
Foods 12 01155 g003 550
Figure 3. Percentage distribution of the number of samples analysed for glyphosate residues in honey samples across continents.
Figure 3. Percentage distribution of the number of samples analysed for glyphosate residues in honey samples across continents.
Foods 12 01155 g003
Table
Table 1. MRL for glyphosate and glufosinate in various countries.
Table 1. MRL for glyphosate and glufosinate in various countries.
CountryMatrixAnalyteMRL
(µg/kg)
EUHoney and
other apiculture products		Glyphosate50
EUHoney and
other apiculture products		Glufosinate
(Sum of glufosinate isomers, its salts, MPP, and N-acetyl-glufosinate)		50
JapanHoney
(Including royal jelly)		Glyphosate
(Sum of glyphosate and N-acetyl-glyphosate)		50
AustraliaHoneyGlyphosate
(Sum of glyphosate, N-acetyl-glyphosate, and AMPA)		200
New ZealandHoneyGlyphosate
(Sum of glyphosate, N-acetyl-glyphosate, and AMPA)		200
Table
Table 2. Comparison of analytical methods for the determination of Gly, AMPA, and Glu in honey and hive products.
Table 2. Comparison of analytical methods for the determination of Gly, AMPA, and Glu in honey and hive products.
Ref.MatrixAnalyteLOD (µg/kg)LOQ (µg/kg)DerivatizationInstrumentation
[36]HoneyGlyphosate1n.r.FMOCLC-MS/MS
AMPA
[37]HoneyGlyphosate310-LC-MS/MS
Beebread
[38]HoneyGlyphosaten.r.25Dansyl clorideLC-MS/MS
AMPA10
Glufosinate10
[39]HoneyGlyphosate
AMPA		110-LC-MS/MS
Beebread
Wax
[40]HoneyGlyphosaten.r.50-LC-MS/MS
Beebread
[41]HoneyGlyphosate2040OPAHPLC-FLD
AMPA
[42]HoneyGlyphosaten.r.9.26-IC-HRMS
AMPA4.3
Glufosinate5.05
[43]HoneyGlyphosaten.r.5-IC-HRMS
AMPA20
[34]HoneyGlyphosaten.r.1FMOCLC-MS/MS
AMPA
Glufosinate
[44]HoneyGlyphosaten.r.15-ELISA
[45]HoneyGlyphosate0.0750.4-ELISA
[46]HoneyGlyphosaten.r.1-LC-MS/MS
AMPA2.5
[47]HoneyGlyphosaten.r.16-LC-MS/MS
[48]HoneyGlyphosaten.r.50-LC-MS/MS
[35]HoneyGlyphosaten.r.15-ELISA
n.r., not reported.
Table
Table 3. Comparison of data on Gly, AMPA, and Glu in honey and other hive products reported in different studies (range, mean and median are expressed in µg/kg).
Table 3. Comparison of data on Gly, AMPA, and Glu in honey and other hive products reported in different studies (range, mean and median are expressed in µg/kg).
MatrixRef.OriginAnalyteTotal
Sample
(Number)		LC
%		Quantifiable Samples
Number%RangeMeanMedian
Honey[36]ArgentinaGly305015502.0–27.5n.r.n.r.
AMPA709301.9–18.1n.r.n.r.
Honey[51]New ZealandGly360797821n.r.n.r.n.r.
Honey[37]ItalyGly8450425010–3417.1n.r.
Honey[52]Various EU countriesGly115947629–55001153270
AMPA351000----
N-Acetyl
Gly		11000----
Glu141000----
N-Acetyl
Glu		11000----
Honey[53]PakistanGly2580520440–35002004n.r.
Honey[39]BelgiumGly1090110111111
AMPA10000---
Honey[54]ItalyGly9810000---
AMPA10000---
Glu10000---
Honey[41]BrazilGly4063153740–220n.r.70
AMPA981220–100--
Honey[55]EUGly24993177n.r.n.r.n.r.
Honey[8]ItalyGly17650885010–790n.r.n.r.
Honey[42]ItalyGly1010000---
AMPA10000---
Glu10000---
Honey[43]Uruguay & EU countriesGly32192681n.r.n.r.n.r.
AMPA10000---
Honey[34]CanadaGly2002197981–49.8n.r.4.9
AMPA1198991–50n.r.10.3
Glu38125621–33n.r.1.4
Honey[56]EUGly1579496n.r.n.r.n.r.
Honey[44]USA
(Hawaii)		Gly5973162715–34233.5 LB
118.3 UB		n.r.
Honey[46]SwitzerlandGly16615941–15.94.63
AMPA10000---
Honey[57]EUGly186872413n.r.n.r.n.r.
Honey[48]EstoniaGly3336216414–6244n.r.
Honey[47]USAGly1644956n.r.n.r.n.r.
Honey[35]USAGly6941415917–63n.r.n.r.
Beebread[37]ItalyGly8446455410–542n.r.n.r.
Beebread[39]BelgiumGly819749110–70055.526
AMPA82211810–25067.144
Wax[39]BelgiumGly10068323210–3206236
AMPA10000---
LC, left-censored; n.r., not reported.
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Rampazzo, G.; Gazzotti, T.; Zironi, E.; Pagliuca, G. Glyphosate and Glufosinate Residues in Honey and Other Hive Products. Foods 2023, 12, 1155. https://doi.org/10.3390/foods12061155

AMA Style

Rampazzo G, Gazzotti T, Zironi E, Pagliuca G. Glyphosate and Glufosinate Residues in Honey and Other Hive Products. Foods. 2023; 12(6):1155. https://doi.org/10.3390/foods12061155

Chicago/Turabian Style

Rampazzo, Giulia, Teresa Gazzotti, Elisa Zironi, and Giampiero Pagliuca. 2023. "Glyphosate and Glufosinate Residues in Honey and Other Hive Products" Foods 12, no. 6: 1155. https://doi.org/10.3390/foods12061155

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop