Pesticide impacts on insect pollinators: Current knowledge and future research challenges.

With the need to intensify agriculture to meet growing food demand, there has been significant rise in pesticide use to protect crops, but at different rates in different world regions. In 2016, the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) global assessment on pollinators, pollination and food production identified pesticides as one of the major drivers of pollinator decline.. This assessment highlighted that studies on the effects of pesticides on pollinating insects have been limited to only a few species, primarily from developed countries. Given the worldwide variation in the scale of intensive agricultural practices, pesticide application intensities are likely to vary regionally and consequently the associated risks for insect pollinators. We provide the first long-term, global analysis of inter-regional trends in the use of different classes of pesticide between 1995 and 2020 (FAOSTAT) and a review of literature since the IPBES pollination assessment (2016). All three pesticide classes use rates varied greatly with some countries seeing increased use by 3000 to 4000 % between 1995 and 2020, while for most countries, growth roughly doubled. We present forecast models to predict regional trends of different pesticides up to 2030. Use of all three pesticide classes is to increase in Africa and South America. Herbicide use is to increase in North America and Central Asia. Fungicide use is to increase across all Asian regions. In each of the respective regions, we also examined the number of studies since 2016 in relation to pesticide use trends over the past twenty-five years. Additionally, we present a comprehensive update on the status of knowledge on pesticide impacts on different pollinating insects from literature published during 2016-2022. Finally, we outline several research challenges and knowledge gaps with respect to pesticides and highlight some regional and international conservation efforts and initiatives that address pesticide reduction and/or elimination.

Enzymatic Degradation toward Herbicides: The Case of the Sulfonylureas.

Commercial herbicides, particularly sulfonylureas, are used worldwide and pose a significant challenge to environmental sustainability. The efficient degradation of sulfonylurea herbicides is critical. SulE, an esterase isolated from the bacterial strain Hansschlegelia zhihuaiae S113, shows degradation activity toward sulfonylurea herbicides. However, the detailed catalytic mechanism remains vague to a large extent. Herein, we decipher the SulEP44R-catalyzed degradation mechanism of sulfonylurea herbicides using hybrid quantum mechanics and molecular mechanics approaches. Our results show that the degradation of sulfonylureas catalyzed by SulEP44R involves four concerted elementary steps. The rate-determining step has an energy barrier range of 19.7-21.4 kcal·mol-1, consistent with the experimentally determined range of 16.0-18.0 kcal·mol-1. Distortion/interaction analysis demonstrates that active-site amino acids play a vital role in the enzymatic catalytic efficacy. The unique architecture of SulEP44R's active site can serve as an excellent template for designing artificial catalysts. Key structural and charge parameters affecting catalytic activity were systematically screened and identified. Based on the elucidated degradation mechanism, several new herbicides with both high herbicidal activity and biodegradability were developed with the aid of a high-throughput strategy. Our findings may advance the application of sulfonylurea herbicides within the framework of environmental sustainability.

Combining capillary electrophoresis and chemometric tools for the straightforward determination of imidazolinone herbicides in plant-based milks.

BACKGROUND: Highly polar herbicides, such as imidazolinones, are used for weed control to increase agricultural productivity and crop quality. However, their misapplication can lead to residues in ready-to-eat food with a potential health risk for consumers. Hence, the fast determination of these herbicides is necessary for timely action. In this work, an eco-friendly method based on capillary zone electrophoresis combined with chemometrics was used for the determination of imazapyr and imazamox in vegetable-based beverages such as soy and quinoa milk. RESULTS: The analytical strategy consisted of only three steps: (i) protein precipitation prior to sample injection (ii) data pre-processing to reduce the background and make corrections on electrophoretic times shift, and (iii) resolution of fully overlapped capillary electrophoresis (CE) peaks by the well-known partial least square (PLS) algorithm, which extracts quantitative information attributed to the analytes. The method was successfully applied in the concentration range between 1.00 and 100 µg L-1 with coefficient of determination of the calibration (R2 cal) and prediction (R2 pred) > 0.90, residual prediction deviation of calibration (RPDcal) and of prediction (RPDpred) > 3, and relative error of prediction (REP) > 11 in the analyzed sample matrices, in the three built methods (quinoa samples, soy samples, and joint quinoa and soy samples). CONCLUSION: The proposed methodology offers a simple and quick alternative for determining imidazolinones at trace concentrations in vegetable beverages, such as quinoa and soy milk, without complex sample preparation. The results were consistent with those obtained using more complex techniques, confirming the applicability of this method. © 2024 Society of Chemical Industry.

Interactions between prosulfocarb and trifluralin metabolism in annual ryegrass (Lolium rigidum).

BACKGROUND: Cross-resistance between pre-emergence herbicides is developing in Australian populations of annual ryegrass (Lolium rigidum Gaud.). A previous study has reported that selection with prosulfocarb (a pro-herbicide requiring bioactivation to its phytotoxic sulfoxide) can decrease metabolic resistance to trifluralin. Metabolism of prosulfocarb and trifluralin was investigated in L. rigidum populations with different levels of resistance to prosulfocarb, trifluralin and also pyroxasulfone, which is detoxified by glutathione (GSH) conjugation. RESULTS: Coleoptiles and radicles of herbicide-treated seedlings responded differently to the same herbicide. Radicles had a lower capacity for bioactivation of prosulfocarb, and this was correlated with a lower ability to metabolise trifluralin within and among populations. Coleoptile resistance to prosulfocarb sulfoxide was negatively correlated with abundance of a major polar metabolite. There was no evidence of GSH conjugation with the sulfoxide, making any potential links between prosulfocarb and pyroxasulfone resistance less obvious. CONCLUSIONS: Activation and metabolism of prosulfocarb in L. rigidum is complex and differentially regulated in different tissues. Selection with prosulfocarb may ameliorate trifluralin metabolism in the radicles, but the relationship between prosulfocarb and pyroxasulfone resistance is not GSH-mediated. When applying pre-emergence herbicides, care should be taken with the composition of mixtures and rotations to avoid selection of cross-resistance between pyroxasulfone and prosulfocarb. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

A review of the potential adverse health impacts of atrazine in humans.

Atrazine is a widely used chlorinated triazine herbicide in agricultural settings, which has raised concerns over its potential adverse effects on human health. The extensive application of atrazine has resulted in its pervasive presence in the environment, contaminating soil, groundwater, and surface water. While earlier research suggested that atrazine is unlikely to pose a health concern, recent evidence has indicated the necessity to reassess this point of view. This review aims to assess the recent evidence on atrazine's adverse effects on human health, focusing on (i) Cancer, (ii) Metabolic Diseases, (iii) Reproductive System, (iv) Neural System, and (v) Epigenetic Effects. Strategies to mitigate atrazine contamination and limitations of previous studies are also discussed. We strongly believe that further investigation is necessary to determine the potential detrimental consequences of atrazine in humans, particularly in developing countries, where herbicides are widely used without stringent safety regulations. Therefore, the current review will be beneficial for guiding future research and regulatory measures concerning the use of atrazine.

Unlocking the potential of bioherbicides for sustainable and environment friendly weed management.

Bioherbicides might be used to manage weeds as opposed to synthetic chemical herbicides, reducing environmental risks and advancing sustainable agriculture in the meantime. Bioherbicides employ different mechanisms of action to control weeds. Microbial bioherbicides may infect and damage weed plants, disrupt their growth, or produce compounds inhibiting weed development. Plant-derived bioherbicides often target specific biochemical processes crucial for weed survival. It can be applied through conventional spraying equipment, seed treatments, or soil incorporation. Bioherbicide development faces several challenges. One major hurdle is the complex diversity of weed species across different regions, requiring tailored bioherbicide solutions. The regulatory approvals for bioherbicides can be lengthy and costly, hindering widespread adoption. Scaling up production processes and ensuring product stability also pose challenges. By reducing reliance on chemical herbicides, bioherbicides can mitigate environmental pollution, protect non-target organisms, and promote sustainable agricultural practices. The development of locally adapted bioherbicides and strategic collaborations between researchers, industries, and policymakers could further enhance their prospects in a particular country. In addition, the knowledge gaps need to be addressed prior to adopting bioherbicides in agriculture. These review intended to explore the existing state of knowledge about the categories of bioherbicides, their formulation procedure, application approaches and mode of action to control weed. The bioherbicides that are currently on the market, their effects on weed physiology, and possible factors affecting their efficacy are all included in this review. Moreover, this review offers a perspective on existing challenges and future opportunities for adopting the bioherbicides in sustainable and eco-friendly agriculture.

Melatonin attenuates affective disorders and cognitive deficits induced by perinatal exposure to a glyphosate-based herbicide via antioxidant pathway in adult male and female rats.

The massive use of herbicides, particularly glyphosate-based herbicides (GBHs), raises several worries, notably their neurotoxic effects. Several studies have explored the consequences of developmental exposure. Our work aims to determine the impact of maternal exposure to GBH on behavioral disorders and memory deficits, as well as the involvement of oxidative stress in the hippocampus and prefrontal cortex. In addition, our study explores the neuroprotective properties of melatonin in male and female offspring. Pregnant Wistar rats were injected with GBH 75 mg/kg during gestation and lactation. After weaning, the offspring were treated with melatonin (4 mg/kg) from postnatal days 30-58. Our results show that GBH increases anxiety-like behavior levels in offspring, as well as depression-like behavior. GBH also impairs working memory in progeny. While markers of oxidative stress show a disturbance in lipid peroxidation and catalase activity, with a more pronounced effect in females, on the other hand, melatonin considerably attenuated the neurotoxic impact observed in the offspring, with higher efficacy in females. The oxidative stress results confirm the antioxidant power of melatonin to counteract the damaging effects of exposure to environmental contaminants such as glyphosate-based pesticides. It will then be interesting to further our work to fully understand the sex-dependent effect of melatonin.

Neuroglycome alterations of hippocampus and prefrontal cortex of juvenile rats chronically exposed to glyphosate-based herbicide.

Introduction: Glyphosate-based herbicides (GBHs) have been shown to have significant neurotoxic effects, affecting both the structure and function of the brain, and potentially contributing to the development of neurodegenerative disorders. Despite the known importance of glycosylation in disease progression, the glycome profile of systems exposed to GBH has not been thoroughly investigated. Methods: In this study, we conducted a comprehensive glycomic profiling using LC-MS/MS, on the hippocampus and prefrontal cortex (PFC) of juvenile rats exposed to GBH orally, aiming to identify glyco-signature aberrations after herbicide exposure. Results: We observed changes in the glycome profile, particularly in fucosylated, high mannose, and sialofucosylated N-glycans, which may be triggered by GBH exposure. Moreover, we found major significant differences in the N-glycan profiles between the GBH-exposed group and the control group when analyzing each gender independently, in contrast to the analysis that included both genders. Notably, gender differences in the behavioral test of object recognition showed a decreased performance in female animals exposed to GBH compared to controls (p < 0.05), while normal behavior was recorded in GBH-exposed male rats (p > 0.05). Conclusion: These findings suggest that glycans may play a role in the neurotoxic effect caused by GBH. The result suggests that gender variation may influence the response to GBH exposure, with potential implications for disease progression and specifically the neurotoxic effects of GBHs. Understanding these gender-specific responses could enhance knowledge of the mechanisms underlying GBH-induced toxicity and its impact on brain health. Overall, our study represents the first detailed analysis of N-glycome profiles in the hippocampus and PFC of rats chronically exposed to GBH. The observed alterations in the expression of N-glycan structures suggest a potential neurotoxic effect associated with chronic GBH exposure, highlighting the importance of further research in this area.

Study of Amino Acid-Derived 3-Acyltetramic Acids as Herbicidal Agents.

The growing problem of herbicide resistance necessitates the development of novel herbicidal active ingredients, together with other integrated weed management approaches. Natural products are a major source of inspiration for novel actives. In previous research, we identified a 3-acyltetramic acid of microbial origin that inhibited algal growth in marine biofilms, at least in part through inhibition of photosystem II. In this work, we demonstrate the herbicidal effect of this lead compound and construct multiple libraries to test the impact of the different substituents of the central scaffold in order to study the structure-activity relationships. Among these analogues, the highest activities were found for medium- to long-chain acyl groups and apolar secondary amino acid residues. Finally, we provide first insights into the herbicidal mechanisms and present preliminary field-trial and ecotoxicological results for TA12-Pro, the most active analogue in our library. Together, this research shows the potential of 3-acyltetramic acids for herbicide development.

A novel potato peels waste ß-cyclodextrin biocomposite for the efficient uptake of diuron and glyphosate herbicides.

A novel biocomposite (FPPW-ß-CD) was prepared by a simple and sustainable method involving fine potato peel waste, ß-cyclodextrin (ß-CD), and green citric acid through the crosslinking reaction. The polymer was characterized using SEM, FTIR, XRD, TGA, and DSC analyses. The adsorbent performance was evaluated about the glyphosate and diuron adsorption from the aqueous solution. Pesticide removal was investigated regarding the influence of solution pH, temperature, and initial concentration of contaminants. Also, it highlights the main interactions involved in the adsorption phenomenon based on the pH effect and characteristics of adsorbent and adsorbate molecules. The maximum adsorption capacity values according to the Sips model were higher than 2000 µg g-1. The pseudo-second-order and general-order models described the kinetic data well. Thermodynamic parameters indicated that pesticide removal was spontaneous and favorable. The magnitude of enthalpy variation values (27.37 kJ mol-1 and - 100.79 kJ mol-1) revealed that the glyphosate and diuron adsorption occurred through the physisorption and chemisorption, respectively. The novel biocomposite is a promising green adsorbent for the uptake of micropollutant pesticides in aqueous solutions at concentrations of µg L-1.

Bio-transformation of poultry litter and activated sewage sludge to produce biomixtures for the remediation of water polluted with pesticides.

The aim of this study was to formulate novel biomixtures with the ability to dissipate globally used pesticides. For this, an effective stabilization of two wastes, poultry litter and activated sewage sludge, was achieved through a combination of composting and vermicomposting, with the aid of the earthworm Eisenia fetida. Hence, two different mixtures were prepared combining the wastes with and without the addition of sewage sludge, and their physicochemical and microbiological characterization was examined during both processes. Earthworms reproduction was promoted by more than fourteen times the initial number of individuals introduced. This step made it possible to obtain substrates rich in organic matter, stable and non-pathogenic. The resulting vermicomposted substrates (V-C1 and V-C2) were used to produce two different biomixtures with wheat stubble (WS) and soil (S): SWSV-C1 and SWSV-C2, and they were tested for the remediation of a solution of five pesticides (2,4-D, cypermethrin, imidacloprid, acetochlor and dimethoate) in a 119-days assay. Comparisons were made with a WS-only biomixture (SWS) and a soil control. All biomixtures were more successful in dissipating the pesticides than soil; 2,4-D, dimethoate, and acetochlor degradation reached more than 99% in the three biomixtures after 28-56 days of assay. Biomixtures containing either vermicomposts acted faster than SWS, particularly for 2,4-D, dimethoate and cypermethrin. The total microbial activity was found to be higher in the two biomixtures containing vermicompost, which can be linked to their enhanced performance in the degradation of pesticides. Although the germination of Lactuca sativa proved that neither of the three spent biomixtures were phytotoxic at the end (germination index >60%), only SWSV-C1 and SWSV-C2 proved to be safe for the survival of E. fetida. This work confirms that vermicompost improves the success of biomixtures, not only in terms of pesticide removal, but also providing non-toxic spent biomixtures.

Residential proximity to agricultural herbicide and fungicide applications and dust levels in homes of California children.

BACKGROUND: Few studies of the relationship between residential proximity to agricultural pesticide applications and pesticide levels in the home have incorporated crop location or wind direction. We evaluated the relationship between agricultural pesticide applications using the California Pesticide Use Reporting (CPUR) database and pesticide concentrations in carpet dust accounting for land use and wind direction. METHODS: We measured concentrations (ng/g) of seven herbicides and two fungicides in carpet dust samples from 578 California homes (2001-2007). We created three metrics by computing the density (kg/km2) of use of each pesticide reported in CPUR within 0.5-, 1-, 2-, and 4-km buffers around homes 180- and 365-days before sampling (CPUR metric). We apportioned applications to the crop area within the buffers (CROP-A metric) and weighted CPUR applications by the proportion of days that the home was within ±45° of the downwind direction (W-CPUR metric). We modeled natural-log concentrations (Tobit regression) and dust detections (logistic regression) adjusting for season/year, occupation, and home/garden use. RESULTS: Detections were >90 % for glyphosate, 2,4-D, and simazine. Detection rates and dust concentrations increased with increasing CPUR densities for all herbicides and one fungicide. Compared to homes without applications within 4 km, the highest tertile of 365-day glyphosate use was associated with ∼100 % higher concentrations (CPURT3>9.2kg/km2 %change = 110, 95 %CI = 55, 183; CROP-AT3>13.4kg/km2 %change = 144, 95 %CI = 81, 229; and W-CPURT3>2.1kg/km2 %change = 102, 95 %CI = 50, 171). The highest density tertiles of 2,4-D, simazine, and trifluralin were associated with 2- to 6-times higher concentrations, respectively; that was similar across metrics. Across all metrics, agricultural use of dacthal, dicamba, and iprodione were associated with 5- to 10-times higher odds of dust detections. Associations were unclear for 2-methyl-4-chlorophenoxyacetic acid and null for chlorothalonil. CONCLUSIONS: Agricultural herbicide and fungicide use was an important determinant of indoor contamination within 4 km of homes. Accounting for crops and wind direction did not substantially change these relationships.

Multisite Mutagenesis of 4-Hydroxyphenylpyruvate Dioxygenase (HPPD) Enhances Rice Resistance to HPPD Inhibitors and Its Carotenoid Contents.

While frequently used herbicides display limited efficacy against herbicide-resistant weeds, it becomes imperative to explore novel herbicides that ensure both effective weed management and environmental safety. Though 4-hydroxyphenylpyruvate dioxygenase (HPPD) inhibitory herbicides like mesotrione are prevalent in maize weed management, their integration into rice production is hindered due to the inherent sensitivity of rice HPPD (OsHPPD). In this study, a mutant allele of OsHPPD featuring six amino acid substitutions, termed OsHPPD-6M, maintains enzymatic activity in 200 µm mesotrione while the wild type can only withstand 1 µm. Enzymatic assays in vitro indicated that the HPPD activity of OsHPPD-6M surpassed that of the WT by 2-fold through enhanced substrate-binding. Its overexpression in transgenic rice conferred greater tolerance to mesotrione, topramezone, and isoxaflutole by 36.7-, 41.6-, and 37.1-fold relative to that in the WT rice. Interestingly, these 6M-OE plants demonstrated substantially elevated contents of carotenoids compared to WT plants without a significant impact on agronomic traits.

Prenatal Exposure to Herbicide 2,4-Dichlorophenoxyacetic Acid (2,4D) Exacerbates Zika Virus Neurotoxicity In Vitro and In Vivo.

Zika virus (ZIKV) infection during pregnancy can lead to a set of congenital malformations known as Congenital ZIKV syndrome (CZS), whose main feature is microcephaly. The geographic distribution of CZS in Brazil during the 2015-2017 outbreak was asymmetrical, with a higher prevalence in the Northeast and Central-West regions of the country, despite the ubiquitous distribution of the vector Aedes aegypti, indicating that environmental factors could influence ZIKV vertical transmission and/or severity. Here we investigate the involvement of the most used agrochemicals in Brazil with CZS. First, we exposed human neuroblastoma SK-N-AS cells to the 15 frequently used agrochemical molecules or derivative metabolites able to cross the blood-brain barrier. We found that a derived metabolite from a widely used herbicide in the Central-West region, 2,4-dichlorophenoxyacetic acid (2,4D), exacerbates ZIKV neurotoxic effects in vitro. We validate this observation by demonstrating vertical transmission leading to microcephaly in the offspring of immunocompetent C57BL/6J mice exposed to water contaminated with 0.025 mg/L of 2,4D. Newborn mice whose dams were exposed to 2,4D and infected with ZIKV presented a smaller brain area and cortical plate size compared to the control. Also, embryos from animals facing the co-insult of ZIKV and 2,4D exposition presented higher Caspase 3 positive cells in the cortex, fewer CTIP2+ neurons and proliferative cells at the ventricular zone, and a higher viral load. This phenotype is followed by placental alterations, such as vessel congestion, and apoptosis in the labyrinth and decidua. We also observed a mild spatial correlation between CZS prevalence and 2,4D use in Brazil's North and Central-West regions, with R2 = 0.4 and 0.46, respectively. Our results suggest that 2,4D exposition facilitates maternal vertical transmission of ZIKV, exacerbating CZS, possibly contributing to the high prevalence of this syndrome in Brazil's Central-West region compared to other regions.

Current Research Status, Opportunities, and Future Challenges of Nine Representative Persistent Herbicides.

Pesticides are extensively utilized in contemporary agriculture to manage pests, enhance crop yields, and sustain productivity. Nevertheless, the persistent herbicide represents a dual-edged weapon. On one hand, their prolonged efficacy enables reduced application frequency during crop growth seasons, resulting in cost savings on labor. However, the presence of these residues within fields poses safety risks to soil quality, sensitive crops in subsequent rotations, agricultural product quality, and the ecological environment. This review presents a comprehensive review on the mechanisms of action, application risks, ecotoxicology, and residue analysis methods of nine representative persistent herbicides (namely, atrazine, imazethapyr, imazapic, mesosulfuron-methyl, halosulfuron-methyl, fomesafen, diflufenican, quinclorac, and pyroxasulfone). The objective is to guide their scientific and rational utilization in agricultural practices while minimizing phytotoxicity risks and effectively monitoring and controlling soil pollution. These can not only provide practical recommendations for mitigating potential plant toxicity and ecological environmental risks but also contribute valuable technical insights for efficient soil pollution monitoring and prevention. Additionally, unaddressed research objectives were also anticipated.

Recent innovations in crop protection research.

As the world's population continues to grow and demand for food increases, the agricultural industry faces the challenge of producing higher yields while ensuring the safety and quality of harvests, operators, and consumers. The emergence of resistance, pest shifts, and stricter regulatory requirements also urgently calls for further advances in crop protection and the discovery of new innovative products for sustainable crop protection. This study reviews recent highlights in innovation as presented at the 15th IUPAC International Congress of Crop Protection Chemistry held in New Delhi, in 2023. The following new products are discussed: the insecticides Indazapyroxamet, Dimpropyridaz and Fenmezoditiaz, the fungicides Mefentrifluconazole and Pyridachlomethyl, the nematicide Cyclobutrifluram, the herbicides Rimisoxafen, Dimesulfazet, and Epyrifenacil as well as the abiotic stress management product Anisiflupurin. In addition, the latest innovative research areas and discovery highlights in all areas of crop protection will be presented, including insecticidal alkyl sulfones and 1,3,4-trisubstituted pyrazoles, fungicidal picolinamides, herbicidal ketoenols, and trifluoromethylpyrazoles, as well as the latest advances in crop enhancement and green pest control research. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Bacterial allelopathy: an approach for biological control of weeds.

Weed infestation is one of the most damaging biotic factors to limit crop production by competing with the crop for space, water, and nutrients. Different conventional approaches are being used to cope with weed infestation, including labor intensive manual removal and the use of soil-degrading, crop-damaging, and environment-deteriorating chemical herbicides. The use of chemicals for weed control has increased 2-fold after the green revolution and their non-judicious use is posing serious threats to mankind, animals, and biodiversity. The detrimental effects of these approaches have shifted the researchers' attention from the last two decades towards alternate, sustainable, and eco-friendly approaches to cope with weed infestation. The recent approaches of weed control, including plant and microbial allelopathy have gained popularity during last decade. Farmers still use conventional methods, but the majority of farmers are very passionate about organic agriculture and describe it as a slogan in the developed world. The effectiveness of these approaches lies in host specificity by selective bacteria and differential response towards weeds and crops. Moreover, the crop growth promoting effect of microorganisms (allelopathic bacteria) possessing various growth promoting traits, that is, mineral solubilization, phytohormone production, and beneficial enzymatic activity, provide additional benefits. The significance of this review lies in the provision of a comprehensive comparison of the conventional approaches along with their potential limitations with advanced/biological weed control approaches in sustainable production. In addition, the knowledge imparted about weed control will contribute to a better understanding of biological control methods.

Degradation of Three Herbicides and Effect on Bacterial Communities under Combined Pollution.

Pesticide residues in soil, especially multiple herbicide residues, cause a series of adverse effects on soil properties and microorganisms. In this work, the degradation of three herbicides and the effect on bacterial communities under combined pollution was investigated. The experimental results showed that the half-lives of acetochlor and prometryn significantly altered under combined exposure (5.02-11.17 d) as compared with those of individual exposure (4.70-6.87 d) in soil, suggesting that there was an antagonistic effect between the degradation of acetochlor and prometryn in soil. No remarkable variation in the degradation rate of atrazine with half-lives of 6.21-6.85 d was observed in different treatments, indicating that the degradation of atrazine was stable. 16S rRNA high-throughput sequencing results showed that the antagonistic effect of acetochlor and prometryn on the degradation rate under combined pollution was related to variation of the Sphingomonas and Nocardioide. Furthermore, the potential metabolic pathways of the three herbicides in soil were proposed and a new metabolite of acetochlor was preliminarily identified. The results of this work provide a guideline for the risk evaluation of combined pollution of the three herbicides with respect to their ecological effects in soil.

Multiclass and multi-residue determination of pesticides and antibiotics in sediment from an aquacultural environment based on modified dispersive solid-phase extraction.

A quick, easy, cheap, effective, rugged, and safe method was developed for the multi-residue analysis of pesticides and antibiotics in aquaculture sediment using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The developed method is based on ultrasonic extraction with acetonitrile and phosphate buffer, salting with sodium chloride, and cleaning with dispersive solid-phase extraction adsorbent using primary secondary amine, C18, and graphitized carbon black, followed by HPLC-MS/MS detection. We optimized different extraction methods and the ratio of the cleanup adsorbents to achieve good recoveries at three spiking levels that ranged from 60.4% to 114% with a relative standard deviation below 15% (n = 6). For all analytes, except for flufenoxuron, the limits of quantification were between 1 and 5 µg/kg (dry weight). The validated method was successfully applied to real samples collected from 20 aquacultural ponds, confirming the feasibility of the proposed method. The concentrations of the target analytes in the sediments (dry weight) were in the ranges of 2.2-35.0 µg/kg for sulfonamides, 0-409.1 µg/kg for quinolones, 0-6.56 µg/kg for macrolides, and 0-4.9 µg/kg for pesticides. Moreover, the co-occurrence of pesticides and antibiotics may potentially pose a high risk to sediment-dwelling organisms in nine out of the 20 investigated locations.

Advances in Understanding the Toxicity of 4-Hydroxyphenylpyruvate Dioxygenase-Inhibiting Herbicides.

4-Hydroxyphenylpyruvate dioxygenase inhibiting herbicides (HIHs) represent a recent class (HRAC group 27) of herbicides that offer many advantages, such as broad-spectrum activity, crop selectivity, and low resistance rates. However, emerging studies have highlighted the potential toxicity of HIHs in the environment. This review aims to provide a comprehensive summary of the toxicity of HIHs toward nontarget organisms, including plants, microorganisms, animals, and humans. Furthermore, the present work discusses the ecological roles of these organisms in the environment and their significance in agriculture. By shedding light on the toxicity of HIHs, this study seeks to raise awareness among end users, including environmentalists, researchers, and farmers, regarding the potential ecological implications of these herbicides. Hopefully, this knowledge can contribute to informed decision-making and sustainable practices in green agriculture and environmental management.