Characterization of near-field temporal and spatial variations of pesticide residues using honeybee specimens as bio-sensing matrices.

This study was prompted by recent reports of the ubiquity of neonicotinoids (neonics) in environment and the likelihood of exposures and health hazards to non-target organisms. We aimed to quantify neonics levels in time- and location-match pollen and nectar samples foraged by honeybees (Apis mellifera) and characterized the temporal and spatial variations using a relative potency factor method to determine the total neonic levels, expressed as the imidacloprid-adjusted total neonics, IMIRPF (ng/g). Six pairs of pollen and nectar samples, a total of twelve samples, were collected from each of the thirty-two experimental hives during the active foraging months of March, April, and June and analyzed for eight neonics. We found 59% and 64% of pollen and nectar contained at least one neonic, respectively. Among those neonic-detected pollen and nectar samples, 45% and 77% of them contained more than one neonic, respectively. Imidacloprid and acetamiprid in pollen and clothianidin and thiamethoxam in nectar accounted for 60% and 83% detection, respectively. The highest 3-month average of IMIRPF in pollen (6.56 ng/g) and nectar (11.19 ng/g) were detected in a location with the predominant production of citrus fruit. The temporal and spatial variations of IMIRPF levels demonstrated the robustness of using paired pollen and nectar data as the bio-sensing matrices to facilitate the assessment of near-field exposure to total neonics and the delineation of risks.

Determination of 3-nitropropionic acid in sugarcane using dispersive solid-phase extraction and gas chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry.

A method for accurately determining 3-nitropropionic acid in sugarcane was established for the first time using gas chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry (GC - APCI-MS/MS). Under acidic conditions, 3-nitropropionic acid is methylated to obtain methyl 3-nitropropionate. The derivative product was purified using dispersive solid-phase extraction (d-SPE) method and analyzed using GC - APCI-MS/MS. The recovery experiments were conducted at three concentrations: low, medium, and high. The recovery rates ranged from 75.1% to 90.2%, the relative standard deviations were <8.2%, and the limit of quantification was 2.0 µg/kg. The method offers the advantage of being accurate, sensitive, and specific, meeting the requirements of the determination of 3-nitropropionic acid in sugarcane.

Elucidating the Gas-Phase Behavior of Nitazene Analog Protomers Using Structures for Lossless Ion Manipulations Ion Mobility-Orbitrap Mass Spectrometry.

2-Benzylbenzimidazoles, or "nitazenes", are a class of novel synthetic opioids (NSOs) that are increasingly being detected alongside fentanyl analogs and other opioids in drug overdose cases. Nitazenes can be 20× more potent than fentanyl but are not routinely tested for during postmortem or clinical toxicology drug screens; thus, their prevalence in drug overdose cases may be under-reported. Traditional analytical workflows utilizing liquid chromatography-tandem mass spectrometry (LC-MS/MS) often require additional confirmation with authentic reference standards to identify a novel nitazene. However, additional analytical measurements with ion mobility spectrometry (IMS) may provide a path toward reference-free identification, which would greatly accelerate NSO identification rates in toxicology laboratories. Presented here are the first IMS and collision cross section (CCS) measurements on a set of fourteen nitazene analogs using a structures for lossless ion manipulations (SLIM)-orbitrap MS. All nitazenes exhibited two high intensity baseline-separated IMS distributions, which fentanyls and other drug and druglike compounds also exhibit. Incorporating water into the electrospray ionization (ESI) solution caused the intensities of the higher mobility IMS distributions to increase and the intensities of the lower mobility IMS distributions to decrease. Nitazenes lacking a nitro group at the R1 position exhibited the greatest shifts in signal intensities due to water. Furthermore, IMS-MS/MS experiments showed that the higher mobility IMS distributions of all nitazenes possessing a triethylamine group produced fragment ions with m/z 72, 100, and other low intensity fragments while the lower mobility IMS distributions only produced fragment ions with m/z 72 and 100. The IMS, solvent, and fragmentation studies provide experimental evidence that nitazenes potentially exhibit three gas-phase protomers. The cyclic IMS capability of SLIM was also employed to partially resolve four sets of structurally similar nitazene isomers (e.g., protonitazene/isotonitazene, butonitazene/isobutonitazene/secbutonitazene), showcasing the potential of using high-resolution IMS separations in MS-based workflows for reference-free identification of emerging nitazenes and other NSOs.

Temporal and spatial trends of imidacloprid-related hazards in France.

Neonicotinoids are the top-selling insecticides worldwide. Because of their method of use, mainly to coat seeds, neonicotinoids have been found to widely contaminate the environment. Their high toxicity has been shown to be a major concern in terms of impact on biodiversity, and the use of these insecticides has been associated with population declines of species in different countries. Despite the widespread recognition of the risk of neonicotinoids to biodiversity, their temporal and spatial use remains poorly known in many countries. Yet this information is essential to address the potential impacts of these pesticides on biodiversity and to inform measures to establish protected areas or biodiversity restoration. The present study relied a large publicly available dataset to characterise the temporal and spatial use in France of imidacloprid, the most widely used neonicotinoid worldwide, as well as analysed water contamination surveys between 2005 and 2022 to assess the contamination of the environment. The results show that imidacloprid was the main neonicotinoid used in France over the study period. This use was spatially structured, with higher use in northern and western France, particularly related to cereal and beet crops area. The water contamination survey indicated that imidacloprid has widely contaminated the environment and consequently increased the risk to biodiversity, especially in counties crossed by the Loire, Seine and Vilaine rivers. This risk increased between 2005 and 2018 due to the higher use of imidacloprid and decreased sharply after 2018 due to its ban, although it was reauthorized by derogation for sugar beet in 2021. This study is the first assessment of imidacloprid pressure on biodiversity in France and shows the spatial and temporal correlation between agricultural practices and the freshwater contamination level. These results will help to identify priority areas for mitigation and restoration measures.

Dissipation behavior and risk assessment of imidacloprid and its metabolites in apple from field to products.

Pesticides play vital roles in controlling pests and boosting crop yields. Imidacloprid is widely used all over the world and may form in agricultural products. The presence of pesticide residues in apples raises serious health concerns. Understanding the residual fate of imidacloprid is critical for food safety and human health. In this study, the dissipation behavior, metabolism, household processing and risk assessment of imidacloprid and its metabolites in apple were investigated from filed to products. Field experiment results suggested that the half-lives of imidacloprid at 5 times the recommended dosage was 1.5 times that of the standard dosage. And the final residues of imidacloprid were less than the established maximum residue limits (MRLs). Clarification and simmering had little effect on the reduction the residues of imidacloprid and its metabolites. The calculated processing factors were lower than 1 for imidacloprid and its metabolites, implying that the residual ratios of imidacloprid and its metabolites in each steps of the food processing were reduced. The risk quotients were <1 for all Chinese people, indicating that acceptable risks associated with dietary exposure to imidacloprid in apple. However, the higher risks were observed in young people than adults, and females faced higher risks than males. Given high residue levels in pomace, imidacloprid and its metabolites should be further studied in commercial byproducts.

Neonicotinoid insecticides in paddy fields: Dissipation dynamics, migration, and dietary risk.

Neonicotinoid insecticides (NNIs) have caused widespread contamination of multiple environmental media and posed a serious threat to ecosystem health by accidently injuring non-target species. This study collected samples of water, soil, and rice plant tissues in a water-soil-plant system of paddy fields after spaying imidacloprid (IMI), thiamethoxam (THM), and clothianidin (CLO) to analyze their distribution characteristics and migration procedures and to assess related dietary risks of rice consumption. In the paddy water, the concentrations of NNIs showed a dynamic change of increasing and then decreasing during about a month period, and the initial deposition of NNIs showed a trend of CLO (3.08 µg/L) > THM (2.74 µg/L) > IMI (0.97 µg/L). In paddy soil, the concentrations of the three NNIs ranged from 0.57 to 68.3 ng/g, with the highest residual concentration at 2 h after application, and the concentration trend was opposite to that in paddy water. The initial deposition amounts of IMI, THM, and CLO in the root system were 5.19, 3.02, and 5.24 µg/g, respectively, showing a gradual decrease over time. In the plant, the initial deposition amounts were 19.3, 9.36, and 52.6 µg/g for IMI, THM, and CLO, respectively, exhibiting concentration trends similar to those in the roots. Except for IMI in soil, the dissipation of the NNIs conformed to the first-order kinetic equation in paddy water, soil, and plant. The results of bioconcentration factors (BCFs) and translocation factor (TF) indicated that NNIs can be bi-directionally transported in plants through leaf absorption and root uptake. The risk of NNIs intake through rice consumption was low for all age groups, with a slightly higher risk of exposure in males than in females.

Following Regulation, Imidacloprid Persists and Flupyradifurone Increases in Nontarget Wildlife.

After regulation of pesticides, determination of their persistence in the environment is an important indicator of effectiveness of these measures. We quantified concentrations of two types of systemic insecticides, neonicotinoids (imidacloprid, acetamiprid, clothianidin, thiacloprid, and thiamethoxam) and butenolides (flupyradifurone), in off-crop nontarget media of hummingbird cloacal fluid, honey bee (Apis mellifera) nectar and honey, and wildflowers before and after regulation of imidacloprid on highbush blueberries in Canada in April 2021. We found that mean total pesticide load increased in hummingbird cloacal fluid, nectar, and flower samples following imidacloprid regulation. On average, we did not find evidence of a decrease in imidacloprid concentrations after regulation. However, there were some decreases, some increases, and other cases with no changes in imidacloprid levels depending on the specific media, time point of sampling, and site type. At the same time, we found an overall increase in flupyradifurone, acetamiprid, thiamethoxam, and thiacloprid but no change in clothianidin concentrations. In particular, flupyradifurone concentrations observed in biota sampled near agricultural areas increased twofold in honey bee nectar, sevenfold in hummingbird cloacal fluid, and eightfold in flowers after the 2021 imidacloprid regulation. The highest residue detected was flupyradifurone at 665 ng/mL (parts per billion [ppb]) in honey bee nectar. Mean total pesticide loads were highest in honey samples (84 ± 10 ppb), followed by nectar (56 ± 7 ppb), then hummingbird cloacal fluid (1.8 ± 0.5 ppb), and least, flowers (0.51 ± 0.06 ppb). Our results highlight that limited regulation of imidacloprid does not immediately reduce residue concentrations, while other systemic insecticides, possibly replacement compounds, concurrently increase in wildlife. Environ Toxicol Chem 2024;43:1497-1508. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Ecological implications and drivers of emerging contaminants in Dongting Lake of Yangtze River Basin, China: A multi-substance risk analysis.

Emerging contaminants (ECs) are increasingly recognized as a global threat to biodiversity and ecosystem health. However, the cumulative risks posed by ECs to aquatic organisms and ecosystems, as well as the influence of anthropogenic activities and natural factors on these risks, remain poorly understood. This study assessed the mixed risks of ECs in Dongting Lake, a Ramsar Convention-classified Typically Changing Wetland, to elucidate the major EC classes, key risk drivers, and magnitude of anthropogenic and natural impacts. Results revealed that ECs pose non-negligible acute (30% probability) and chronic (70% probability) mixed risks to aquatic organisms in the freshwater lake ecosystem, with imidacloprid identified as the primary pollutant stressor. Redundancy analysis (RDA) and structural equation modeling (SEM) indicated that cropland and precipitation were major drivers of EC contamination levels and ecological risk. Cropland was positively associated with EC concentrations, while precipitation exhibited a dilution effect. These findings provide critical insights into the ecological risk status and key risk drivers in a typical freshwater lake ecosystem, offering data-driven support for the control and management of ECs in China.

Aptamer-based biosensors for the detection of neonicotinoid insecticides in environmental samples: A systematic review.

Neonicotinoids, sometimes abbreviated as neonics, represent a class of neuro-active insecticides with chemical similarities to nicotine. Neonicotinoids are the most widely adopted group of insecticides globally since their discovery in the late 1980s. Their physiochemical properties surpass those of previously established insecticides, contributing to their popularity in various sectors such as agriculture and wood treatment. The environmental impact of neonicotinoids, often overlooked, underscores the urgency to develop tools for their detection and understanding of their behavior. Conventional methods for pesticide detection have limitations. Chromatographic techniques are sensitive but expensive, generate waste, and require complex sample preparation. Bioassays lack specificity and accuracy, making them suitable as preliminary tests in conjunction with instrumental methods. Aptamer-based biosensor is recognized as an advantageous tool for neonicotinoids detection due to its rapid response, user-friendly nature, cost-effectiveness, and suitability for on-site detection. This comprehensive review represents the inaugural in-depth analysis of advancements in aptamer-based biosensors targeting neonicotinoids such as imidacloprid, thiamethoxam, clothianidin, acetamiprid, thiacloprid, nitenpyram, and dinotefuran. Additionally, the review offers valuable insights into the critical challenges requiring prompt attention for the successful transition from research to practical field applications.

Risk analysis for groundwater intakes based on the example of neonicotinoids.

Neonicotinoids are a class of broad-spectrum insecticides that are dominant in the world market. They are widely distributed in the environment. Understanding the sources, distribution, and fate of these contaminants is critical to mitigating their effects and maintaining the health of aquatic ecosystems. Contamination of surface and groundwater by neonicotinoids has become a widespread problem worldwide, requiring comprehensive action to accurately determine the mechanisms behind the migration of these pesticides, their properties, and their adverse effects on the environment. A new approach to risk analysis for groundwater intake contamination with emerging contaminants was proposed. It was conducted on the example of four neonicotinoids (acetamiprid, clothianidin, thiamethoxam, and imidacloprid) in relation to groundwater accessed by a hypothetical groundwater intake, based on data obtained in laboratory tests using a dynamic method (column experiments). The results of the risk analysis conducted have shown that in this case study the use of acetamiprid and thiamethoxam for agricultural purposes poses an acceptable risk, and does not pose a risk to the quality of groundwater extracted from the intake for food purposes. Consequently, it does not pose a risk to the health and life of humans and other organisms depending on that water. The opposite situation is observed for clothianidin and imidacloprid, which pose a higher risk of groundwater contamination. For higher maximum concentration of neonicotinoids used in the risk analysis, the concentration of clothianidin and imidacloprid in the groundwater intake significantly (from several to several hundred thousand times) exceeds the maximum permissible levels for drinking water (<0.1 µg/L). This risk exists even if the insecticides containing these pesticides are used according to the information sheet provided by the manufacturer (lower maximum concentration), which results in exceeding the maximum permissible levels for drinking water from several to several hundred times.

A sensitive fluoroimmunoassay for quantitative detection of imidacloprid based on quantum dot-streptavidin conjugate.

Imidacloprid (IMI), the most commonly used neonicotinoid, is widely present in both the environment and agro-products due to extensive and prolonged application, posing potential risks to ecological security and human health. This study introduced a sensitive and rapid fluorescence-linked immunosorbent assay, employing Quantum Dot-Streptavidin conjugate (QDs-SA-FLISA), for efficient monitoring of IMI residues in agro-products. Under optimized conditions, the QDs-SA-FLISA exhibited a half-maximal inhibition concentration (IC50) of 1.70 ng/mL and a limit of detection (LOD, IC20) of 0.5 ng/mL. Investigation into the sensitivity enhancement effect of the QDs-SA revealed that the sensitivity (IC50) of the QDs-SA-FLISA was 7.3 times higher than that of ELISA. The recoveries and relative standard deviation (RSD) ranged from 81.7 to 118.1 % and 0.5-9.4 %, respectively, for IMI in brown rice, tomato and pear. There was no significant difference in IMI residues obtained between QDs-SA-FLISA and UHPLC-MS/MS. Thus, the QDs-SA-FLISA represents a reliable approach for the quantitative determination of IMI in agro-products.

Exposure of Male Farmers and Nonfarmers to Neonicotinoid Pesticides in the South-West and Littoral Regions of Cameroon: A Comparative Study.

Pesticides, especially the newly developed neonicotinoids, are increasingly used in many countries around the world, including Cameroon, to control pests involved in crop destruction or disease transmission. Unfortunately, the pesticides also pose tremendous environmental problems because a predominant amount of their residues enter environmental matrices to affect other nontargeted species including humans. This therefore calls for continuous biomonitoring of these insecticides in human populations. The present study sought to assess the neonicotinoid insecticide exposures in two agrarian regions of Cameroon, the South-West region and Littoral region. The study involved 188 men, including 125 farmers and 63 nonfarmers. Spot urine samples were obtained from these subjects and subjected to liquid chromatographic-tandem mass spectrometric analysis for concentrations of neonicotinoid compounds, including acetamiprid, clothianidin, dinotefuran, imidacloprid, thiacloprid, nitenpyram, thiamethoxam, and N-dm-acetamiprid. Neonicotinoid compounds were detected in all study participants, and residues of all the screened pesticides were detected among participants. N-dm-Acetamiprid and imidacloprid were the most prevalent among the subjects (100.0% and 93.1%, respectively), whereas nitenpyram was less common (3.2%). The median values of imidacloprid and total urinary neonicotinoid concentrations were elevated among farmers (0.258 vs. 0.126 µg/L and 0.829 vs. 0.312 µg/L, respectively). Altogether the findings showed that both the farmer and nonfarmer study populations of Cameroon were exposed to multiple residues of neonicotinoids, with relatively higher levels of pesticides generally recorded among farmers. Although exposure levels of the neonicotinoids were generally lower than their respective reference doses, these results warrant further research on the health risk evaluation of multiple residues of the pesticides and reinforcement of control measures to minimize the exposure risks, especially among farmers. Environ Toxicol Chem 2024;43:952-964. © 2024 SETAC.

Comprehensive analysis of neonicotinoids in Chinese commercial honey and pollen: A corresponding health risk assessment for non-targeted organisms.

Neonicotinoids are broad-spectrum and highly effective insecticides that work by affecting neural activity in insects. Neonicotinoids are systemic pesticides that are absorbed by plants, transported, and accumulated in plant tissues, including nectar and pollen. Currently, there is a lack of a comprehensive assessment of the level of neonicotinoid contamination and the associated health risks to non-targeted organisms in commercial honey and pollen produced in China. This study collected 160 batches of honey and 26 batches of pollen from different regions and plant sources in China, analyzed the residue patterns of neonicotinoid pesticides, and comprehensively evaluated the exposure risks to non-targeted organisms including bees (adults and larvae) and humans. Furthermore, this study addresses this imperative by establishing a high-throughput, rapid, and ultra-sensitive indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) based on broad-spectrum monoclonal antibodies to detect and quantify neonicotinoids, with validation conducted using the LC-MS/MS method. The findings indicated that 59.4 % of honey samples contained at least one of eight neonicotinoids, and the ic-ELISA rapid detection and calculation method could detect all the samples containing neonicotinoids. Additionally, the dietary risk assessment for humans and honeybees indicates that the consumption of a specific quantity of honey may not pose a health risk to human due to neonicotinoid intake. However, the Risk Quotient values for imidacloprid to adult bees and bee larvae, as well as clothianidin to bee larvae, were determined to be 2.22, 5.03, and 1.01, respectively-each exceeding 1. This highlights the elevated risk of acute toxicity posed by imidacloprid and clothianidin residues to honey bees. The study bears significant implications for the safety evaluation of non-targeted organisms in the natural food chain. Moreover, it provides scientific guidance for protecting the diversity and health of the ecosystem.

Pesticide residues in adults living near a bioenergy plant with 85,000 tons of contaminated wetcake.

Neonicotinoid insecticide use is on the rise worldwide due to its broad-spectrum insecticidal action and exclusive approach of neurotoxic action. Besides application during the cultivation of several crops, all seed companies coat their seeds with neonicotinoids to have increased protection against insects during germination. Despite reduced mammalian toxicity, neonicotinoids have harmful effects on non-target non-mammalian organisms such as bees, an essential part of maintaining the ecosystem. In addition, epidemiologic studies have linked human exposure to neonicotinoids with poor developmental and neurological outcomes. Starting in 2015, the AltEn bioenergy plant near Mead, Nebraska, USA, used coated seeds for their ethanol production and failed to properly dispose of byproducts, causing environmental contamination that still exists. This pilot study reports the human urinary levels of neonicotinoids in samples collected during 2022-2023 in the population living in areas close to this now-closed bioenergy plant. Our results show that approximately 30% of the urine samples are contaminated with at least one of the targeted neonicotinoids or their transformed products. The most frequently detected parent neonicotinoid was clothianidin, which accounts for 13% of the samples. However, 5-hydroxy-imidacloprid, the transformed imidacloprid product, is detected in 27% of the samples, ranging from 1.2 to 42 ng/mL. In conclusion, the environmental contamination near Mead, Nebraska, due to improper storage and disposal of highly contaminated byproducts, puts the nearby population at risk from continuous exposure to neonicotinoids through air and dust particles and possible water contamination.

Behavioral and physiological changes in the passerine Agelaioides badius following the ingestion of coated seeds with imidacloprid in a 30-day experiment.

The wide use of neonicotinoid seed treatment represents a hazard for farmland birds that feed on treated seeds. This study aimed to characterize the long-term effects of the neonicotinoid imidacloprid (IMI) in the passerine grayish baywing (Agelaioides badius). The birds were fed ad libitum for 32 days only with seeds treated with 53.1 (Low, 11 % of LD50) and 514 (High, (112 % of LD50) mg IMI/kg seed; these concentrations representing respectively, 1.8 and 17.1 % of 3 g IMI/kg, an average application rate used to treat crop seeds in Argentina. The effects exerted by IMI on birds were evaluated at behavioral, physiological, hematological, genotoxic, and biochemical levels. No differences in food consumption were observed between Control and Low treatments birds, indicating a lack of aversion to treated seeds. High treatment birds only decreased their food consumption by 20 % in the first 3 days of exposure. Birds from High treatment experienced an early loss of body weight, reduction in their mobility, lack of response to threats (i.e., predator call and approaching person), and altered their use of the cage. On the contrary, birds from Low treatment experienced a delay in the onset of effects like reduction in mobility, lack of response to threats, and a tendency to reduce their body weight. At the end of exposure, glutathione S transferase activity in the plasma of treated birds decreased, and cholinesterase activity increased in the liver of treated birds. This study highlights that consumption equivalent to 1.8 % of the daily diet of baywings as IMI-treated seeds, is sufficient to generate behavioral and physiological alterations and death. In the wild, these effects may have ecological consequences, by impairing the survival of birds, representing a risk to farmland bird populations.

Application of pesticide application measures to reduce residue based on the metabolic transfer law of imidacloprid in banana leaves and soil.

An investigation of the metabolism and transfer of imidacloprid (IMI) in banana plants and soil was performed using high-resolution mass spectrometry. Results indicated the presence of eight IMI metabolites in soil and leaves that resulted from hydroxylation of the imidazolidine ring, the reduction and loss of nitro groups, and oxidative cleavage of methylene bridges. Six metabolites, including 4/5-hydroxy IMI (4/5-hydroxy), IMI olefin (olefin), and 6-chloronicotinic acid (6-CNA), were detected in the fruits following leaf treatment, while only three were detected after soil treatment. Quantitative analysis showed that the total amount of imidacloprid and its metabolites transferred from leaves to fruits was higher than that transferred from soil to fruits. Therefore, leaf transfer was considered the main means by which IMI and its metabolites transferred to banana fruits. We found that adjuvants tank-mixed with IMI could reduce the total concentration of pesticide transfer from leaves to fruits, especially reducing the amount of metabolites transformed from the reduction and loss of nitro groups and oxidative cleavage of methylene bridges, thus reducing the pesticide residue in fruits and achieving the purpose of reducing the safety risk.

Neonicotinoids in tea leaves and infusions from China: Implications for human exposure.

The ingestion of contaminated tea involves the risk of human exposure to residues of neonicotinoids (NEOs). Nevertheless, there is little empirical research about this topic; to bridge the current knowledge gap, we collected 220 samples of various tea products from four geographical areas in China, including unfermented green tea, semi-fermented white tea and oolong tea, completely fermented black tea, and post-fermented dark tea. A total of six NEOs were detected from the tea leaves and infusions, namely, dinotefuran (DIN), thiamethoxam (THM), clothianidin (CLO), imidacloprid (IMI), acetamiprid (ACE), and thiacloprid (THI). The detection frequencies (DFs) and concentrations of all target NEOs were relatively high across the investigated tea samples, and the DIN, IMI and ACE residues measured in some samples exceeded the maximum residue level (MRL) standards for the European Union. Samples representing the Jiangnan area exhibited greater levels of total target NEOs (∑6NEOs) than samples representing the Jiangbei area (p < 0.001). Moreover, dark tea samples were found to have far higher levels of NEO residues than green (p < 0.001), white (p < 0.05), or oolong (p < 0.001) samples. The health risks associated with exposure to NEO residues via tea were small for both children and adults in terms of acute, chronic, and cumulative dietary exposure risk assessments. The transfer rates (TRs) of NEOs observed in white, black, and dark tea infusions gradually decreased after the third brewing time. As such, it is recommended to only consume tea that has been brewed at least three times. The presented results not only describe the extent of NEO contamination in Chinese tea leaves and infusions, but also provide tea drinking guidelines for consumers.

A critical review on the accumulation of neonicotinoid insecticides in pollen and nectar: Influencing factors and implications for pollinator exposure.

Neonicotinoids are a class of neuro-active insecticides widely used to protect major crops, primarily because of their broad-spectrum insecticidal activity and low vertebrate toxicity. Owing to their systemic nature, plants readily take up neonicotinoids and translocate them through roots, leaves, and other tissues to flowers (pollen and nectar) that serve as a critical point of exposure to pollinators foraging on treated plants. The growing evidence for potential adverse effects on non-target species, especially pollinators, and persistence has raised serious concerns, as these pesticides are increasingly prevalent in terrestrial and aquatic systems. Despite increasing research efforts, our understanding of the potential toxicity of neonicotinoids and the risks they pose to non-target species remains limited. Therefore, this critical review provides a succinct evaluation of the uptake, translocation, and accumulation processes of neonicotinoids in plants and the factors that may affect the eventual build-up of neonicotinoids in pollen and nectar. The role of plant species, as well as the physicochemical properties and application methods of neonicotinoids is discussed. Potential knowledge gaps are identified, and questions meriting future research are suggested for improving our understanding of the relationship between neonicotinoid residues in plants and exposure to pollinators.

Behavioral and physiological response of the passerine bird Agelaioides badius to seeds coated with imidacloprid.

Neonicotinoids are globally used insecticides, and there are increasing evidence on their negative effects on birds. This study is aimed at characterizing the behavioral and physiological effects of the neonicotinoid imidacloprid (IMI) in a songbird. Adults of Agelaioides badius were exposed for 7 days to non-treated peeled millet and to peeled millet treated with nominal concentrations of 75 (IMI1) and 450 (IMI2) mg IMI/kg seed. On days 2 and 6 of the trial, the behavior of each bird was evaluated for 9 min by measuring the time spent on the floor, the perch, or the feeder. Daily millet consumption, initial and final body weight, and physiological, hematological, genotoxic, and biochemical parameters at the end of exposure were also measured. Activity was greatest on the floor, followed by the perch and the feeder. On the second day, birds exposed to IMI1and IMI2 remained mostly on the perch and the feeder, respectively. On the sixth day, a transition occurred to sectors of greater activity, consistent with the disappearance of the intoxication signs: birds from IMI1 and IMI2 increased their time on the floor and the perch, respectively. Control birds always remained most of the time on the floor. IMI2 birds significantly decreased their feed intake by 31% the first 3 days, compared to the other groups, and significantly decreased their body weight at the end of the exposure. From the set of hematological, genotoxic, and biochemical parameters, treated birds exhibited an alteration of glutathione-S-transferase activity (GST) in breast muscle; the minimal effects observed are probably related to the IMI administration regime. These results highlight that the consumption of less than 10% of the bird daily diet as IMI-treated seeds trigger effects at multiple levels that can impair bird survival.

Changing on the Concentrations of Neonicotinoids in Rice and Drinking Water through Heat Treatment Process.

Neonicotinoids (NEOs) have become the most widely used insecticides in the world since the mid-1990s. According to Chinese dietary habits, rice and water are usually heated before being consumed, but the information about the alteration through the heat treatment process is very limited. In this study, NEOs in rice samples were extracted by acetonitrile (ACN) and in tap water, samples were extracted through an HLB cartridge, then, a high-performance liquid chromatography system and a triple quadrupole mass spectrometry (HPLC-MS/MS) were applied for target chemical analysis. The parents of NEOs (p-NEOs) accounted for >99% of the total NEOs mass (∑NEOs) in both uncooked (median: 66.8 ng/g) and cooked (median: 41.4 ng/g) rice samples from Guangdong Province, China, while the metabolites of NEOs (m-NEOs) involved in this study accounted for less than 1%. We aimed to reveal the concentration changes of NEOs through heat treatment process, thus, several groups of rice and water samples from Guangdong were cooked and boiled, respectively. Significant (p < 0.05) reductions in acetamiprid, imidacloprid (IMI), thiacloprid, and thiamethoxam (THM) have been observed after the heat treatment of the rice samples. In water samples, the concentrations of THM and dinotefuran decreased significantly (p < 0.05) after the heat treatment. These results indicate the degradation of p-NEOs and m-NEOs during the heat treatment process. However, the concentrations of IMI increased significantly in tap water samples (p < 0.05) after heat treatment process, which might be caused by the potential IMI precursors in those industrial pesticide products. The concentrations of NEOs in rice and water can be shifted by the heat treatment process, so this process should be considered in relevant human exposure studies.