Residues of organochlorine and synthetic pyrethroid pesticides in honey, an indicator of ambient environment, a pilot study

Human exposure to endocrine-disrupting organochlorine and organophosphate pesticides in locally produced and imported honey in Nigeria

The practice of exposing honeybees to pesticides by bee-keepers or via agricultural crops, is one of the ways in which honey becomes contaminated with pesticides. Though honey has many health advantages, however, human exposure to pesticides via consumption of honey has generated public health concerns due to their endocrine-disruptive abilities. Thus, this study evaluated human exposure to endocrine-disrupting pesticides in honey from Nigeria to establish the safety of honey consumed in Nigeria. Honey were analyzed for pesticides using a gas chromatograph combined with an electron capture detector. The concentrations of ∑20 OCPs and ∑14 OPPs in the honey ranged from 0.45-1045 ng/g and 1.13-632 ng/g respectively. The values of both individual and cumulative non-carcinogenic and carcinogenic risks for humans were <1 and 1 × 10-4 respectively suggesting that there are no potential health risks via the honey consumption. The source analysis showed that pesticides in these honey originated from historical and recent/fresh use.

Contaminant dynamics in honey bees and hive products of apiaries from environmentally contrasting Argentinean regions

Argentina is a leading honey producer and honey bees are also critical for pollination services and wild plants. At the same time, it is a major crop producer with significant use of insecticides, posing risks to bees. Therefore, the presence of the highly toxic insecticide chlorpyrifos, and forbidden contaminants (organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs)) was investigated in honey bee, beebread, wax and honey samples in apiaries from three contrasting regions of Argentina. Chlorpyrifos was detected in all samples with higher levels during period 1 (spring) in contrast to period 2 (fall), agreeing with its season-wise use in different crops, reaching 3.05 ng/g in honey bees. A subsequent first-tier pesticide hazard analysis revealed that it was relevant to honey bee health, mainly due to the high concentrations found in wax samples from two sites, reaching 132.4 ng/g. In addition, wax was found to be the most contaminated matrix with a prevalence of OCPs (∑OCPs 58.23-172.99 ng/g). Beebread samples showed the highest concentrations and diversity of pesticide residues during period 1 (higher temperatures). A predominance of the endosulfan group was registered in most samples, consistent with its intensive past use, especially in Central Patagonia before its prohibition. Among the industrial compounds, lighter PCB congeners dominated, suggesting the importance of atmospheric transport. The spatio-temporal distribution of pesticides shows a congruence with the environmental characteristics of the areas where the fields are located (i.e., land use, type of productive activities and climatic conditions). Sustained monitoring of different pollutants in beekeeping matrices is recommended to characterize chemical risks, assess the health status of honey bee hives and the pollution levels of different agroecosystems. This knowledge will set a precedent for South America and be helpful for actions focused on the conservation of pollination services, apiculture and ecosystems in Argentina.

Spatial distribution of two acaricides and five neonicotinoids in beehives and surrounding environments in China

Managed bees commonly suffer from cross-contamination with acaricides and neonicotinoids, posing robust threats to bee population health. However, their residual characteristics and spatial distribution in beehives and surrounding environments are poorly understood. This study detected two common acaricides and five neonicotinoids in 240 beehive samples and 44 surrounding environmental samples collected from 25 Chinese provinces. The results showed that 40.0% of the honey samples contained acaricides and 83.1% contained neonicotinoids. Neonicotinoid concentrations in honey were geographically distinguished by the "Hu Huanyong line", and concentrations of neonicotinoids in honey from eastern areas were 2.65-fold higher than those in honey from western areas. Compared to the approved acaricide amitraz, the banned acaricide coumaphos was detected more frequently in honey and was positively correlated with that quantified in the paired pollen samples. Although coumaphos was identified in only three soil samples, lower coumaphos residues in honey might be associated with persistent pollution in the surrounding environment. Conversely, neonicotinoids were detected at higher levels in honey than in the pollen and soil, demonstrating that the neonicotinoid residues in honey have a cumulative effect. This study contributes to a better understanding of the pesticide contamination scenarios that underlie the exposure risks of bees.

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.

Honey contamination from plant protection products approved for cocoa (Theobroma cacao) cultivation: A systematic review of existing research and methods

The main component of chocolate, cocoa (Theobroma cacao), is a significant commercial agricultural plant that directly sustains the livelihoods of an estimated forty to fifty million people. The economies of many cocoa producing nations, particularly those in the developing world, are supported by cocoa export revenue. To ensure satisfactory yields, however, the plant is usually intensely treated with pesticides because it is vulnerable to disease and pest attacks. Even though pesticides help protect the cocoa plant, unintended environmental contamination is also likely. Honey, produced from nectar obtained by honeybees from flowers while foraging, can serve as a good indicator for the level of pesticide residues and environmental pesticide build-up in landscapes. Here, we use a systematic literature review to quantify the extent of research on residues of pesticides used in cocoa cultivation in honey. In 81% of the 104 studies examined for this analysis, 169 distinct compounds were detected. Imidacloprid was the most frequently detected pesticide, making neonicotinoids the most frequently found class of pesticides overall. However, in cocoa producing countries, organophosphates, organochlorines, and pyrethroids were the most frequently detected pesticides. Interestingly, only 19% of studies were carried out in cocoa producing countries. We recommend prioritizing more research in the countries that produce cocoa to help to understand the potential impact of pesticide residues linked with cocoa cultivation in honey and the environment more generally to inform better pesticide usage, human health, and environmental policies.

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.

Levels of Contamination by Pesticide Residues, Polycyclic Aromatic Hydrocarbons (PAHs), and 5-Hydroxymethylfurfural (HMF) in Honeys Retailed in Europe

Honey is consumed worldwide because of its nutritional, therapeutic and medicinal properties. Generally, honey should reach the consumer in a pure form, but it is often contaminated in various ways. Thus, this study was designed to check for the presence of pesticide residues, polycyclic aromatic hydrocarbon (PAH) levels, and the content of 5-hydroxymethylfurfural (HMF) in selected European honeys (26 samples) obtained from shops. The most frequently detected organochlorine pesticide (OCPs) was 4,4'-DDD, which was found in fourteen honey samples. Slovakian rapeseed honey was most polluted due to the presence of eight OCPs. The presence of organophosphorus pesticides (OPs) was detected in all the analysed samples, and at least one OP in each tested sample exceeded the acceptable limit. PAHs were detected in most of the analysed samples. As for PAH4s, benzo[a]pyrene was found in forest honey from Slovakia and in Polish lime tree honey, whereas wild flower honey from the UK contained the highest level of PAH4. The investigated honeys from Spain and France met the requirements for HMF content, while honeys of Slovak, Italian and Polish origin in most cases exceeded the established levels (40 mg/kg).

Organophosphate Pesticides and Pyrethroids in Farmland of the Pearl River Delta, China: Regional Residue, Distributions and Risks

A regional-scale survey was conducted to assess the occurrence, distribution, and risk of two extensively used pesticides (organophosphate pesticides and pyrethroids) in agricultural soils from the Pearl River Delta (PRD), South China. All target organophosphate pesticides (OPPs) and pyrethroids (PYs) were detected in the soil samples and both with a detection rate of 100%. The residues of the sum of six OPPs and the sum of four PYs were in the range of LOD-991 ng/g and 8.76-2810 ng/g, respectively. Dimethoate was the dominant OPPs, and fenpropathrin was the predominant PYs in the soils of the PRD region. With intensive agricultural activities, higher residues of OPPs and PYs in soils were detected closer to the seaside, among which Zhuhai city and Huizhou city suffered more serious combined pesticide pollution. The vertical compositional profiles showed that dimethoate could be detected through each soil layer in the PRD region's nine cities. The human exposure estimation of OPPs showed insignificant risks to the local population. In contrast, cypermethrin and fenpropathrin showed a potential ecological risk of 2.5% and 3.75% of the sampling sites, respectively. These results can facilitate those commonly used pesticide controls and promote sustainable soil management.

Analyses of Botrytis cinerea-responsive LrWRKY genes from Lilium regale reveal distinct roles of two LrWRKY transcription factors in mediating responses to B. cinerea

Botrytis cinerea induced expression of 15 LrWRKY genes; overexpression of LrWRKY39 and LrWRKY41a increased resistance and susceptibility, respectively, to B. cinerea in a manner related to SA and JA signaling. WRKY transcription factors (TFs), a large family, play important roles in coping with biotic stresses. Lilium regale Wilson is a lily species with strong resistance to fungi and viruses; however, functional characterization of LrWRKY TFs remains very limited. Here, a total of 25 LrWRKY members were identified from the L. regale transcriptome, and 15 LrWRKY genes were significantly induced by Botrytis cinerea. Based on their structural features, B. cinerea-responsive LrWRKY genes could be classified into six subgroups (Groups I, IIa-d, and III), and sequence alignment showed that 12 LrWRKY proteins have a well-conserved WRKYGQK domain, while 3 LrWRKYs have a variant sequence (WRKYGKK or WRMYEQK). Quantitative RT-PCR analysis revealed tissue-specific expression of B. cinerea-responsive LrWRKY genes and their expression profiles in response to defense-related hormones salicylic acid (SA), methyl jasmonate (MeJA) and hydrogen peroxide. LrWRKY39 and LrWRKY41a, which encode two LrWRKY TFs with different three-dimensional (3D) models of the WRKY domain, were cloned, and both proteins were targeted to the nucleus. Overexpression of LrWRKY39 and LrWRKY41a in Arabidopsis thaliana increased the resistance and susceptibility to B. cinerea, respectively, compared to the wild type. Similar results were also observed in tobacco and lily (L. longiflorum 'Snow Queen') by transient transformation analyses. Their distinct roles may be related to changes in the transcript levels of SA-/JA-responsive genes. Our results provide new insights into B. cinerea-responsive LrWRKY members and the biological functions of two different 3D models of LrWRKY TFs in defense responses to B. cinerea infection.

Honey as a bioindicator of environmental organochlorine insecticides contamination

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

Cardiotoxicity of some pesticides and their amelioration

Pesticides are used to control pests that harm plants, animals, and humans. Their application results in the contamination of the food and water systems. Pesticides may cause harm to the human body via occupational exposure or the ingestion of contaminated food and water. Once a pesticide enters the human body, it may create health consequences such as cardiotoxicity. There is not enough information about pesticides that cause cardiotoxicity in the literature. Currently, there are few reports that summarized the cardiotoxicity due to some pesticide groups. This necessitates reviewing the current literature regarding pesticides and cardiotoxicity and to summarize them in a concrete review. The objectives of this review article were to summarize the advances in research related to pesticides and cardiotoxicity, to classify pesticides into certain groups according to cardiotoxicity, to discuss the possible mechanisms of cardiotoxicity, and to present the agents that ameliorate cardiotoxicity. Approximately 60 pesticides were involved in cardiotoxicity: 30, 13, and 17 were insecticides, herbicides, and fungicides, respectively. The interesting outcome of this study is that 30 and 13 pesticides from toxicity classes II and III, respectively, are involved in cardiotoxicity. The use of standard antidotes for pesticide poisoning shows health consequences among users. Alternative safe medical management is the use of cardiotoxicity-ameliorating agents. This review identifies 24 ameliorating agents that were successfully used to manage 60 cases. The most effective agents were vitamin C, curcumin, vitamin E, quercetin, selenium, chrysin, and garlic extract. Vitamin C showed ameliorating effects in a wide range of toxicities. The exposure mode to pesticide residues, where 1, 2, 3, and 4 are aerial exposure to pesticide drift, home and/or office exposure, exposure due to drinking contaminated water, and consumption of contaminated food, respectively. General cardiotoxicity is represented by 5, whereas 6, 7, 8 and 9 are electrocardiogram (ECG) of hypotension due to exposure to OP residues, ECG of myocardial infraction due to exposure to OPs, ECG of hypertension due to exposure to OC and/or PY, and normal ECG respectively.

Organochlorine pesticides in honeybee, pollen and honey in Bursa, Turkey

g-In this study, the presence of OCP residues in the honeybee, pollen and honey samples in urban and semi-urban areas were investigated. A total of 10 OCP concentrations (∑₁₀OCP) in honeybee samples were 39.14 ± 11.06 ng g^-1 for the urban area and 39.93 ± 7.09 ng g^-1 for the semi-urban area, respectively. Similarly, ∑₁₀OCP concentrations in pollen and honey samples were estimated to be 21.72 ± 4.43 ng g^-1 and 41.83 ± 1.61 ng g^-1 for the urban area, 19.77 ± 2.86 ng g^-1 and 39.23 ± 3.90 ng g^-1 for the semi-urban area, respectively. Also, it was concluded that the existence of OCP residues in both sampling areas was due to the recent use of pesticides. Finally, the cancer risk caused by the consumption of pollen and honey samples was evaluated, and it was found that there was no cancer risk in both sampling areas.

Organochlorine pesticide residues in Uganda's honey as a bioindicator of environmental contamination and reproductive health implications to consumers

Honey has multifaceted nutritional and medicinal values; however, its quality is hinged on the floral origin of the nectar. Taking advantage of the large areas that they cover; honeybees are often used as bioindicators of environmental contamination. The focus of the present paper was to examine the quality of honey from within the vicinity of an abandoned pesticide store in Masindi District in western Uganda. Surficial soils (<20 cm depths) and honey samples were collected from within the vicinity of the abandoned pesticide store and analysed for organochlorine pesticide (OCP) residues using gas chromatograph coupled to an electron capture detector (GC-ECD). The mean level of ∑DDTs in all the soil samples was 503.6 µg/kg dry weight (d.w). ∑DDTs contributed 92.2% to the ∑OCPs contamination loads in the soil samples, and others (lindane, aldrin, dieldrin, and endosulfans) contributed only 7.8%. Ratio (p, p'-DDE+p, p'-DDD)/p, p'-DDT of 1.54 suggested historical DDT input in the area. In all the honey samples, the mean level of ∑DDTs was 20.9 µg/kg. ∑DDTs contributed 43.3% to ∑OCPs contamination loads in the honey samples, followed by lindane (29.8%), endosulfans (23.6%) and dieldrin (3.2%), with corresponding mean levels of 14.4, 11.4 and 1.55 µg/kg, respectively. Reproductive risk assessment was done based on the hazard quotient (HQ) and hazard index (HI) procedure. In our study, the calculated HIs for adults (102.38), and children (90.33) suggested high potential health risks to the honey consumers. Lindane, endosulfan and p, p'-DDD detected in the honey samples at levels exceeding the acute reference dose (ARfD) are known risk factors for spontaneous abortion, reduced implantation, menstrual cycle shortening, impaired semen quality, and prostate cancer in exposed individuals and experimental animal models.

Susceptibility of Various Developmental Stages of the Fall Armyworm, Spodoptera frugiperda, to Entomopathogenic Nematodes

Simple Summary

The fall armyworm, Spodoptera frugiperda, native to Central and South America, has recently invaded Africa and Asia, causing serious economic damage to various crops. The chemical control of fall armyworm is not effective due to the development of pesticide resistance as well as environmental contamination. Alternatively, biological control using natural enemies can be used successfully in a sustainable way. Entomopathogenic nematodes are soil-dwelling natural enemies for many underground pest insects including lepidopteran caterpillars. This study evaluates the virulence of several entomopathogenic nematodes on different developmental stages of fall armyworm. We found that all the larval and pupal stages of fall armyworm were highly susceptible to the entomopathogenic nematodes. Our study provides important information of entomopathogenic nematodes for the practical application of biological control of fall armyworm.

Abstract

The fall armyworm, Spodoptera frugiperda, which is native to Central and South America, has recently invaded Africa and Asia, causing serious damage to various crops. Although management to date has been largely unsuccessful, entomopathogenic nematodes (EPNs) are a potential biological control agent that could be used to control the late larval and pupal stages of S. frugiperda that dwell under the ground. Here, we compared the virulence of seven EPNs against larval and pupal stages of S. frugiperda. In a Petri dish assay, both Heterorhabditis indica and Steinernema carpocapsae were highly virulent against younger larvae, whereas S. arenarium and S. longicaudum were highly virulent against older larvae. In contrast, H. bacteriophora, Heterorhabditis sp., and S. kushidai showed low virulence against all larval stages. In soil column and pot assays, H. indica, S. carpocapsae, and S. longicaudum were highly virulent against late larval and pupal stages compared with the other EPN species. Thus, H. indica, S. carpocapsae, and S. longicaudum are recommended for the biological control of S. frugiperda. Our study provides important information of EPNs for the practical application of biological control of fall armyworm.

Pesticide residues in honey and their potential reproductive toxicity

Honey is the sweet natural substance produced by honeybees. It may be contaminated with pesticide residues due to its intensive use. Almost no reviews have addressed pesticide residues in honey, calculated a hazard index or discussed their potential reproductive toxicity. The focus of this article is primarily to summarize advances in research related to pesticide residues, estimate daily intake of pesticide residues from consuming honey only and discuss the potential reproductive toxicity associated with those residues. The results showed that 92 pesticide residues were found in honey samples from 27 countries. Six residues belong to class IA toxicity, eight residues belong to class IB toxicity, 42 residues belong to class II, 35 residues belong to class III and one residue belong to class IV toxicity. The calculated hazard indices (HIs) suggest high potential health risk by consuming honey. In addition, residues found in honey are known to impair semen quality among exposed individuals and experimental animal models. In conclusion, consumption of honey as one of many food items contaminated with pesticide residues may induce male and female reproductive toxicity in consumers.

Optimization of Method for Pesticide Detection in Honey by Using Liquid and Gas Chromatography Coupled with Mass Spectrometric Detection

This study aimed to optimize and validate a multi-residue method for identifying and quantifying pesticides in honey by using both gas and liquid chromatographic separation followed by mass spectrometric detection. The proposed method was validated to detect 168 compounds, 127 of them by LC-MS/MS (liquid chromatography tandem mass spectrometric detection) and 41 by GC-MS/MS (gas chromatography tandem mass spectrometric detection). The limit of detection (LOD) and limit of quantification (LOQ) values for the analytes determined by LC-MS/MS were 0.0001–0.0004 mg/kg and 0.0002–0.0008 mg/kg, respectively. For GC-MS/MS analyses, the LOD and LOQ values were 0.001–0.004 mg/kg and 0.002–0.008 mg/kg. In total, 33 samples of commercial honey produced by apiaries in six Brazilian states were analyzed with the validated method. Residual amounts of 15 analytes were detected in 31 samples (93.9%). The method described in the present study was able to detect an extensive and broad range of pesticides with very high sensitivity.

Photodegradation of Organophosphorus Pesticides in Honey Medium by Solar Light Irradiation

In this study, the photodegradation of organophosphorus (OPs) pesticides in the honey medium was evaluated under sunlight irradiation. Some of the 22 samples collected at different sites contained OPs pesticides (Methyl parathion, Coumaphos and Fenitrothion) with an average of 8 ng/g. Moreover, three samples were found with pesticide residue levels exceeding the maximum residue limits (MRL ≥ 50 ng/g) imposed by the standard water (WHO). Gas chromatography (GC) combined with a tritium electron capture detector system was used for the analysis of OPs pesticides in honey. Total degradation of the Methyl parathion was obtained in less than 60 min of irradiation. Moreover, the elimination of the other OPs found in the samples was also effective with a rate of 85% for Coumaphos and Fenitrothion after 50 min of sunlight irradiation. The kinetics of the photodegradation reaction of all OPs pesticides studied followed a pseudo-first order model.

Influence of land use on chlorpyrifos and persistent organic pollutant levels in honey bees, bee bread and honey: Beehive exposure assessment

This work reports the spatial and temporal variations on the dynamics of OCPs, PCBs, PBDEs and chlorpyrifos in honey bee, bee bread and honey samples, as well as soil and flowers from the surrounding areas, considering, different land uses. Honey bee samples showed the highest pollutant levels, with a predominance of the industrial contaminants over pesticides. Chlorpyrifos showed the highest concentration during the application period in almost all samples from the soybean field (S2), in concordance with its current use. By other hand, the recalcitrant compounds such as, DDTs, BDE #47 and also light PCBs exhibited the highest levels in beehive samples from the field adjacent to urban disposal waste (S3). In both soils and flower samples a prevalence of obsolete compounds over chlorpyrifos was observed, and the 6-CB predominated among the homologous groups of PCBs These results highlights the importance of soils as sink of these persistent contaminants, which became available depending on environmental conditions. Results revealed that the land uses and seasonal variations have directly impacted on the levels of agrochemicals, PCBs and PBDEs found in the beehive matrixes. This survey provides novel evidence about the current situation of pollution on honey bee colonies under temperate climates and contributes to the knowledge of this poor studied topic in Argentina.

RNAi-Based Biofungicides as a Promising Next-Generation Strategy for Controlling Devastating Gray Mold Diseases

Botrytis cinerea is one of the most critical agro-economic phytopathogens and has been reported to cause gray mold disease in more than 1000 plant species. Meanwhile, small interfering RNA (siRNA), which induce RNA interference (RNAi), are involved in both host immunity and pathogen virulence. B. cinerea has been reported to use both siRNA effectors and host RNAi machinery to facilitate the progression of gray mold in host species. Accordingly, RNAi-based biofungicides that use double-stranded RNA (dsRNA) to target essential fungal genes are considered an emerging approach for controlling devastating gray mold diseases. Furthermore, spray-induced gene silencing (SIGS), in which the foliar application of dsRNA is used to silence the pathogen virulence genes, holds great potential as an alternative to host-induced gene silencing (HIGS). Recently, SIGS approaches have attracted research interest, owing to their ability to mitigate both pre- and post-harvest B. cinerea infections. The RNAi-mediated regulation of host immunity and susceptibility in B. cinerea–host interactions are summarized in this review, along with the limitations of the current knowledge of RNAi-based biofungicides, especially regarding SIGS approaches for controlling gray mold diseases under field conditions.

Impact of pyrethroids and organochlorine pesticides residue on IGF-1 and CYP1A genes expression and muscle protein patterns of cultured Mugil capito

This study aimed to assess the levels of pyrethroids and organochlorine residues in the tissues of cultured Mugil capito and in water samples obtained from three different sites (Al-Hamol, Al-Riad and Sidi Salem; referred to as Area 1, Area 2, and Area 3, respectively) in the Delta region, Egypt. The study also assessed the biochemical markers in exposed mullet and evaluated the impact of these residues on the expression of insulin-like growth factor 1 (IGF-1) in muscle and cytochrome P4501A (CYP1A) in liver tissues using qRT-PCR and SDS-PAGE methods. The results revealed that pesticide residue levels in the water were variable, but were lower than detected levels in fish. Significant (P < 0.05) differences were found across the three study areas in terms of serum ALT, but the serum AST level was not significantly (P > 0.05) elevated in all study regions. Serum creatinine and urea levels were significantly (P < 0.05) elevated in area 3. Furthermore, glutathione and malondialdehyde concentrations significantly increased (P < 0.05) in liver tissues in area 3. Using the qRT-PCR technique, the results revealed that the expression level of IGF-1 was most significant in area 3, while the expression level of CYP1A was most significant in area 1. The protein profile showed some differences in band numbers and molecular weights of protein bands across different regions. Overall, the alteration in biochemical parameters revealed pesticide interference with the metabolic processes of fish. Furthermore, the pesticide pollution had an effect on the expression of IGF-1 and CYP1A genes and led to changes in the protein profile. Therefore, these markers can be used to monitor fish distress following exposure to the pollutant.

Flumethrin at sublethal concentrations induces stresses in adult honey bees (Apis mellifera L.)

Flumethrin is a typical pyrethroid varroacide widely used for mite control in beekeeping worldwide. Currently, information on the toxicological characteristics of flumethrin on bees at sublethal concentrations is still lacking. To fill this gap in information, we performed a 48-h acute oral and 14-day chronic toxicity testing of flumethrin in newly emerged adult honey bees under laboratory conditions. Results showed that flumethrin had high acute toxicity to honey bees with a 48-h LD₅₀ of 0.47 µg/bee (95% CI, 0.39 ∼ 0.57 µg/bee), which is higher than that of many other commercial pyrethroid insecticides, but lower than that of tau-fluvalinate. After 14 days of chronic exposure to flumethrin at 0.01, 0.10, and 1.0 mg/L, significant antioxidant response, detoxification, immune reaction, and apoptosis were observed in the midguts. These findings indicated that flumethrin had potential risks to bees, and it can disturb the homeostasis of bees at sublethal concentrations under longer exposure conditions. Flumethrin is highly lipophilic and easy to accumulate in beeswax; thus, careless practices might pose risks to colony development in commercial beekeeping and native populations. This laboratory study can serve as an early warning, and further studies are required to understand the real residual level of flumethrin in bees and the risks of flumethrin in field condition.

Potential Risk to Pollinators from Nanotechnology-Based Pesticides

The decline in populations of insect pollinators is a global concern. While multiple factors are implicated, there is uncertainty surrounding the contribution of certain groups of pesticides to losses in wild and managed bees. Nanotechnology-based pesticides (NBPs) are formulations based on multiple particle sizes and types. By packaging active ingredients in engineered particles, NBPs offer many benefits and novel functions, but may also exhibit different properties in the environment when compared with older pesticide formulations. These new properties raise questions about the environmental disposition and fate of NBPs and their exposure to pollinators. Pollinators such as honey bees have evolved structural adaptations to collect pollen, but also inadvertently gather other types of environmental particles which may accumulate in hive materials. Knowledge of the interaction between pollinators, NBPs, and other types of particles is needed to better understand their exposure to pesticides, and essential for characterizing risk from diverse environmental contaminants. The present review discusses the properties, benefits and types of nanotechnology-based pesticides, the propensity of bees to collect such particles and potential impacts on bee pollinators.

Host-induced gene silencing of BcTOR in Botrytis cinerea enhances plant resistance to grey mould

Botrytis cinerea is the causal agent of grey mould for more than 200 plant species, including economically important vegetables, fruits and crops, which leads to economic losses worldwide. Target of rapamycin (TOR) acts a master regulator to control cell growth and proliferation by integrating nutrient, energy and growth factors in eukaryotic species, but little is known about whether TOR can function as a practicable target in the control of plant fungal pathogens. Here, we characterize TOR signalling of B. cinerea in the regulation of growth and pathogenicity as well as its potential value in genetic engineering for crop protection by bioinformatics analysis, pharmacological assays, biochemistry and genetics approaches. The results show that conserved TOR signalling occurs, and a functional FK506-binding protein 12 kD (FKBP12) mediates the interaction between rapamycin and B. cinerea TOR (BcTOR). RNA sequencing (RNA-Seq) analysis revealed that BcTOR displayed conserved functions, particularly in controlling growth and metabolism. Furthermore, pathogenicity assay showed that BcTOR inhibition efficiently reduces the infection of B. cinerea in plant leaves of Arabidopsis and potato or tomato fruits. Additionally, transgenic plants expressing double-stranded RNA of BcTOR through the host-induced gene silencing method could produce abundant small RNAs targeting BcTOR, and significantly block the occurrence of grey mould in potato and tomato. Taken together, our results suggest that BcTOR is an efficient target for genetic engineering in control of grey mould, and also a potential and promising target applied in the biocontrol of plant fungal pathogens.

Pesticide and veterinary drug residues in honey - validation of methods and a survey of organic and conventional honeys from Slovenia

Four analytical methods were developed and validated for the determination of veterinary drug residues and environmental pesticide residues in honey: (a) GC-MS method for the analysis of amitraz and all metabolites containing the 2,4-dimethylaniline moiety; (b) GC-MS method for the analysis of thymol, chlorfenvinphos and coumaphos; (c) GC-MS method for the analysis of 75 active substances; (d) LC-MS/MS method for the analysis of 60 active substances. Between the GC-MS (method c) and the LC-MS/MS method (method d) there was no overlap among active substances, meaning that using both methods 135 active substances originating from the environment in total were included and validated. The first method involved hydrolysis of amitraz and its metabolites containing the 2,4-dimethylaniline moiety to 2,4-dimethylaniline and extraction of 2,4-dimethylaniline to n-hexane. The other three methods had the same extraction procedure with a mixture of solvents: acetone, dichloromethane and petroleum ether. All 4 methods were tested in practice. Sixty samples of honey were analysed: 22 from organic and 38 from conventional production. Overall, residues were mainly higher than reported in literature but did not exceed MRLs. Risk assessment confirmed that the analysed samples are of no cause for concern for consumers.

Optimization of the Data Treatment Steps of a Non-targeted LC-MS-Based Workflow for the Identification of Trace Chemical Residues in Honey

Non-targeted screening (e.g., suspected-target) is emerging as an attractive tool to investigate the occurrence of contaminants in food. The sample preparation and instrument analysis steps are known to influence the identification of analytes with non-targeted workflows, especially for complex matrices. However, for methods based on mass spectrometry, the impact of the post-analysis data treatment (e.g., feature extraction) on the capacity to correctly identify a contaminant at trace level is currently not well understood. The aim of the study was to investigate the influence of seven post-analysis data treatment parameters on the non-targeted identification of trace contaminants in honey using high-performance liquid chromatography coupled to hybrid quadrupole time-of-flight mass spectrometry (HPLC-QTOF-MS). Seven compounds reported as veterinary drugs for honeybees were applied as model compounds. Among the parameters studied, the expansion window for chromatogram extraction and the average scans included in the spectra influenced significantly the identification process results. The optimized data treatment was applied to the non-targeted screening of veterinary drugs, pesticides, and other contaminants in 55 honey samples as a proof of concept. Among the 43 compounds included in a library of honey-related compounds that was used for screening, eight compounds were tentatively identified in at least one honey sample. The tentative identity of two of these compounds (tylosin A and hydroxymethylfurfural) was further confirmed with analytical standards. Graphical Abstract.

The use of vegetation, bees, and snails as important tools for the biomonitoring of atmospheric pollution-a review

The continuous discharge of diverse chemical products in the environment is nowadays of great concern to the whole world as some of them persist in the environment leading to serious diseases. Several sampling techniques have been used for the characterization of this chemical pollution, although biomonitoring using natural samplers has recently become the technique of choice in this field due to its efficiency, specificity, and low cost. In fact, several living organisms known as biomonitors could accumulate the well-known persistent environmental pollutants allowing their monitoring in the environment. In this work, a review on environmental biomonitoring is presented. The main sampling techniques used for monitoring environmental pollutants are first reported, followed by an overview on well-known natural species used as passive samplers and known as biomonitors. These species include conifer needles, lichen, mosses, bees and their byproducts, and snails, and were widely used in recent research as reliable monitors for environmental pollution.

Environmental Chemical Contaminants in Food: Review of a Global Problem

Contamination by chemicals from the environment is a major global food safety issue, posing a serious threat to human health. These chemicals belong to many groups, including metals/metalloids, polycyclic aromatic hydrocarbons (PAHs), persistent organic pollutants (POPs), perfluorinated compounds (PFCs), pharmaceutical and personal care products (PPCPs), radioactive elements, electronic waste, plastics, and nanoparticles. Some of these occur naturally in the environment, whilst others are produced from anthropogenic sources. They may contaminate our food-crops, livestock, and seafood-and drinking water and exert adverse effects on our health. It is important to perform assessments of the associated potential risks. Monitoring contamination levels, enactment of control measures including remediation, and consideration of sociopolitical implications are vital to provide safer food globally.

Pesticide residues in Indian raw honeys, an indicator of environmental pollution

Honey has multifaceted beneficial properties, but polluted environment and unapproved apicultural practices have led to its contamination. In this study, QuEChERS method followed by chromatographic analysis by GC-μECD/FTD and GC-MS was validated and used for determination of 24 pesticides in 100 raw honey samples from various floral origins of Northern India. Matrix-matched calibrations showed that the method was selective and linear (r² > 0.99) with detection limit < 9.1 ng g^-1 for all the studied pesticides except for monocrotophos (21.3 ng g^-1). The average recoveries at different fortification levels ranged from 86.0 to 107.7% with relative standard deviation < 20%. Pesticide residues were detected in 19.0% samples, and most prevalent compounds detected were dichlorvos in 6.0% samples followed by monocrotophos (5.0%), profenofos (5.0%), permethrin (4.0%), ethion (3.0%), and lindane (3.0%) with concentrations ranging from 58.8 to 225.5, from 96.0 to 430.1, from 14.6 to 43.2, from 27.8 to 39.6, from 25.6 to 28.0, and from 19.6 to 99.2 ng g^-1, respectively. Honey samples originating from cotton, sunflower, and mustard crops (33.3%) that tested positive for pesticide residues were found to be significantly higher (p < 0.05) than the honey originating from natural and fruity vegetation (13.5%). Therefore, considering the contamination of environmental compartments due to extensive application of pesticides in the study area and their potential for subsequent transfer to honey by the expeditious bees, the results of present study proclaim that honey may be used as an indicator of environmental pollution. Further, estimated daily intakes of all contaminants were found to be at levels well below their acceptable daily intakes suggesting that consumption of honeys at current levels does not pose deleterious effects on human health. However, precautionary measures should always be taken considering the customary honey feeding in infants and cumulative effect of these chemicals in the foreseeable future.

Determination of 16 PAHs and 22 PCBs in honey samples originated from different region of Lebanon and used as environmental biomonitors sentinel

In order to assess the air quality in some Lebanese regions, a biomonitoring study based on honey as biomonitor candidate was conducted. For this, 18 samples of honey collected from four regions in Lebanon, were analyzed for their contamination by 16 polycyclic aromatic hydrocarbons (PAHs) and 22 polychlorinated biphenyls (PCBs). Samples were first extracted using a multi-residue extraction method based on the quick, easy, cheap, effective, rugged, and safe extraction method (QuEChERS) followed by a concentration step using Solid-phase microextraction (SPME) procedures. The extraction was then followed by chromatographic analysis by gas chromatography-ion-trap tandem mass spectrometry (GC-MS/MS). After PAHs samples assessment, different ratios of founded PAHs were calculated in order to estimate the sources of the pollution by these compounds. The obtained results showed that the four analyzed regions were contaminated with PAHs originated from both pyro and petro genic sources while none of them was found to be contaminated by any of the 22 assessed PCBs. The results of this study show that honey can be used as potential biomonitor candidate allowing the assessment of the pollution statement of a given environment.

Organochlorine Pesticides in Honey and Pollen Samples from Managed Colonies of the Honey Bee Apis mellifera Linnaeus and the Stingless Bee Scaptotrigona mexicana Guérin from Southern, Mexico

In this paper, we show the results of investigating the presence of organochlorine pesticides in honey and pollen samples from managed colonies of the honey bee, Apis mellifera L. and of the stingless bee Scaptotrigona mexicana Guérin. Three colonies of each species were moved into each of two sites. Three samples of pollen and three samples of honey were collected from each colony: the first collection occurred at the beginning of the study and the following ones at every six months during a year. Thus the total number of samples collected was 36 for honey (18 for A. mellifera and 18 for S. mexicana) and 36 for pollen (18 for A. mellifera and 18 for S. mexicana). We found that 88.44% and 93.33% of honey samples, and 22.22% and 100% of pollen samples of S. mexicana and A. mellifera, respectively, resulted positive to at least one organochlorine. The most abundant pesticides were Heptaclor (44% of the samples), γ-HCH (36%), DDT (19%), Endrin (18%) and DDE (11%). Despite the short foraging range of S. mexicana, the number of pesticides quantified in the honey samples was similar to that of A. mellifera. Paradoxically we found a small number of organochlorines in pollen samples of S. mexicana in comparison to A. mellifera, perhaps indicating a low abundance of pollen sources within the foraging range of this species.

Simultaneous determination of pyridaben, dinotefuran, DN and UF in eggplant ecosystem under open-field conditions: Dissipation behaviour and residue distribution

A sensitive method for simultaneous determination of pyridaben, dinotefuran, DN and UF in eggplant ecosystem was established and validated through rapid resolution liquid chromatography triples quadrupole tandem mass spectrometry (RRLC-QqQ-MS/MS). Matrix-matched external calibrations were introduced to check matrix effects. Limits of quantification (LOQs) of pyridaben, dinotefuran, DN and UF in eggplant were 0.2, 0.2, 1.0 and 1.0 μg kg^-1, and 0.2, 0.2, 5.0 and 1.0 μg kg^-1 in soil, respectively. Limits of detection (LODs) of four pesticides were below 0.41 μg L^-1. The mean recoveries (n = 5) of these insecticides varied from 79.4% to 103%, and the relative standard deviations (RSDs) ranged from 2.1% to 15.3% at three levels. This method was applied to Chinese open-field samples from two representative locations, which were previously treated with these insecticides at the doses of 210-315 g a.i. ha^-1 twice or three times. The dissipations of pyridaben and dinotefuran in eggplant and soil followed first-order kinetics with the half-lives of 3.65-11.4 d. The residues of pyridaben and total dinotefuran (calculated as sum of dinotefuran parent, DN and UF) in eggplant were below 0.0311 mg kg^-1 at the pre-harvest interval (PHI, 7 d). Presently, no maximum residue limit (MRL) of pyridaben and dinotefuran in eggplant was recommended by China, Codex Alimentarius Commission (CAC) or European Union (EU). This study was important for evaluation of environmental fate and food safety of pyridaben and dinotefuran in eggplant ecosystems, and facilitated China to establish maximum residue limits (MRLs) of pyridaben and dinotefuran in eggplant.

Simultaneous determination of organochlorine and pyrethriod pesticide residues in the Chinese patent medicines by gas chromatography-tandem mass spectrometry

A simple, sensitive, reliable method was developed for the simultaneous determination of organochlorine and pyrethriod pesticide residues in Chinese patent medicines Six ingredient rehmannia pills and Xiaoyao pills. These pesticides were extracted by ethyl acetate. The extraction time and volume of ethyl acetate were optimized. Cleanup of extracts was performed with dispersive-solid phase extraction using graphitized carbon black as the sorbent. The determination of pesticides in the final extracts was carried out by gas chromatography-tandem mass spectrometry in multiple reaction monitoring mode (GC-MS/MS, MRM). The linearity of the calibration curves is good in matrix-matched standard and yields the coefficients of determination (R²) ≥0.99 for all of the target analytes. Under optimized conditions, the average recoveries (five replicates) for most pesticides range from 75.5% to 114.6%, and RSDs are less than 10.0%. The LODs of 18 pesticides in Six ingredient rehmannia pill and Xiaoyao pills are in the range of 0.01-8.82 μg kg^-1. The developed method meets the requirements of pesticide residue analysis and could be effectively used for routine analysis of the organochlorine and pyrethriod pesticide residues in Six ingredient rehmannia pills and Xiaoyao pills.

Pyrethroid pesticide residues in the global environment: An overview

Pyrethroids are synthetic organic insecticides with low mammalian toxicity that are widely used in both rural and urban areas worldwide. After entering the natural environment, pyrethroids circulate among the three phases of solid, liquid, and gas and enter organisms through food chains, resulting in substantial health risks. This review summarized the available studies on pyrethroid residues since 1986 in different media at the global scale and indicated that pyrethroids have been widely detected in a range of environments (including soils, water, sediments, and indoors) and in organisms. The concentrations and detection rates of agricultural pyrethroids, which always contain α-cyanogroup (α-CN), such as cypermethrin and fenvalerate, decline in the order of crops > sediments > soils > water. Urban pyrethroids (not contain α-CN), such as permethrin, have been detected at high levels in the indoor environment, and 3-phenoxybenzoic acid, a common pyrethroid metabolite in human urine, is frequently detected in the human body. Pyrethroid pesticides accumulate in sediments, which are a source of pyrethroid residues in aquatic products.

Are pesticide residues in honey related to oilseed rape treatments?

Pesticide treatments before and during the flowering of honey bee forage crops may lead to residues in honey. In northern regions oilseed rape belongs to the main forage crops that is mostly cultivated by means of intensive agriculture, including several pesticide treatments. However, in addition to the focal forage crops, pesticides from non-forage crops can spread to wild flowers around fields, and thus the residues in honey would reflect the whole range of pesticides used in the agricultural landscape. The aim of our study was to clarify which currently used pesticides are present in honey gathered from heterogeneous agricultural landscapes after the end of flowering of oilseed crops. Honey samples (N = 33) were collected from beehives of Estonia during 2013 and 2014, and analysed for residues of 47 currently used agricultural pesticides using the multiresidue method with HPLC-MS/MS and GC-MS and a single residue method for glyphosate, aminopyralid and clopyralid. Residues of eight different active ingredients with representatives from all three basic pesticide classes were determined. Although no correlation was detected between the cumulative amount of pesticide residues and percent of oilseed crops in the foraging territory, most of the residues are those allowed for oilseed rape treatments. Among all pesticides, herbicide residues prevailed in 2013 but not in 2014. Despite the relatively small agricultural impact of Estonia, the detected levels of pesticide residues sometimes exceeded maximum residue level; however, these concentrations do not pose a health risk to consumers, also acute toxicity to honey bees would be very unlikely.

The exposure of honey bees (Apis mellifera; Hymenoptera: Apidae) to pesticides: Room for improvement in research

Losses of honey bees have been repeatedly reported from many places worldwide. The widespread use of synthetic pesticides has led to concerns regarding their environmental fate and their effects on pollinators. Based on a standardised review, we report the use of a wide variety of honey bee matrices and sampling methods in the scientific papers studying pesticide exposure. Matrices such as beeswax and beebread were very little analysed despite their capacities for long-term pesticide storage. Moreover, bioavailability and transfer between in-hive matrices were poorly understood and explored. Many pesticides were studied but interactions between molecules or with other stressors were lacking. Sampling methods, targeted matrices and units of measure should have been, to some extent, standardised between publications to ease comparison and cross checking. Data on honey bee exposure to pesticides would have also benefit from the use of commercial formulations in experiments instead of active ingredients, with a special assessment of co-formulants (quantitative exposure and effects). Finally, the air matrix within the colony must be explored in order to complete current knowledge on honey bee pesticide exposure.

Neonicotinoids transference from the field to the hive by honey bees: Towards a pesticide residues biomonitor

The beehive as a quantitative monitor of pesticide residues applied over a soybean crop was studied through a semi field experiment of controlled exposure of honey bees to pesticides in macro tunnels. The distribution within exposed beehives of pesticides commonly used in soybean plantation, was assessed. Residue levels of insecticides in soybean leaves, honey bees, wax, honey and pollen were analyzed. The transference from pesticides present in the environment into the beehive was evidenced. The obtained results allow relating pesticide concentrations present in the environment with traces found in foraging bees. Therefore, pesticide transference ratios could be calculated for each detected compound (acetamiprid, imidacloprid and thiamethoxam) which showed a linear inverse trend with their 1-octanol/water partition coefficient (Kow). The least transferred pesticide to the hive (acetamiprid) has the highest vapor pressure (Vp). This study gives new insights on the usefulness of monitoring the environment through beehives aiming to evaluate if agroecosystems remain sustainable. It also contributes to generate valuable information for model building aiming to predict environmental quality through beehive's analysis.

Identification of multi-insecticide residues using GC-NPD and the degradation kinetics of chlorpyrifos in sweet corn and soils

Because more than one insecticide is applied to crops to protect plants from pests, an analytical multi-residue determination method was developed using gas chromatography with a nitrogen phosphorus detector (GC-NPD). The retention time for 12 insecticides was 3.7-27.7min. Under the selected conditions, the limits of detection (LOD) and quantification (LOQ) were below the maximum residue limits (MRLs) and in the range of 0.00315-0.05μgmL(-1) and 0.01-0.165μgmL(-1), respectively. Using GC-NPD, we investigated the dissipation dynamics and final residual levels of chlorpyrifos in sweet corn and soil and determined that the half-lives was 4-7days, that is, that chlorpyrifos is safe to use on sweet corn with a pre-harvest interval of 16-22days before harvest. These results provide new insights into chlorpyrifos degradation in plants and its environmental behavior.

Bee pollen as a bioindicator of environmental pesticide contamination

Honeybees and bee products are potential bioindicators of the presence of contaminants in the environment, enabling monitoring of large areas due to the long distances travelled by bees. This work evaluates the use of bee pollen as a bioindicator of environmental contamination by pesticides. A GC-MS/MS analytical method for multiresidue determination of 26 different pesticides in pollen was developed and validated in accordance with the recommendations of the European Union SANCO guide. Environmental monitoring was conducted using the analysis of 145 pollen samples collected from ten beehives in the experimental apiary of Embrapa in Jaguariúna (São Paulo State, Brazil). Bioallethrin and pendimethalin were identified in four and eighteen samples, respectively, at concentrations below the LOQ of the method (25 ng g(-1)). Passive sampling with polyurethane foam discs was used as a control, and no pesticides were found. The detection of pesticide residues in seven samples (33%) from commercial apiaries in Ribeirão Preto (São Paulo State) confirmed the efficiency of the analytical method and the need for environmental monitoring for the presence of pesticide residues. The results demonstrated the potential of bee pollen as a bioindicator of environmental contamination by pesticides.