Biochemical and molecular-level effects of co-exposure to chlorpyrifos and lambda-cyhalothrin on the earthworm (Eisenia fetida).

Farmland soil organisms frequently encounter pesticide mixtures presented in their living environment. However, the underlying toxic mechanisms employed by soil animals to cope with such combined pollution have yet to be explored. This investigation aimed to reveal the changes in cellular and mRNA levels under chlorpyrifos (CPF) and lambda-cyhalothrin (LCT) co-exposures in earthworms (Eisenia fetida). Results exhibited that the combination of CPF and LCT triggered an acute synergistic influence on the animals. Most exposures resulted in significant alterations in the activities of total superoxide dismutase (T-SOD), copper/zinc superoxide dismutase (Cu/Zn-SOD), caspase 3, and carboxylesterase (CarE) compared to the basal level. Moreover, when exposed to chemical mixtures, the transcription levels of four genes [heat shock protein 70 (hsp70), gst, sod, and calreticulin (crt)] also displayed more pronounced changes compared with their individual exposures. These changes in determined parameters indicated the occurrence of oxidative stress, cell death, detoxification dysfunction, and endoplasmic reticulum damage after co-exposure to CPF and LCT in E. fetida. The comprehensive examination of mixture toxicities of CPF and LCT at different endpoints would help to understand the overall toxicity they cause to soil invertebrates. The augmented deleterious effect of these pesticides in a mixture suggested that mixture toxicity assessment was necessary for the safety evaluation and application of pesticide mixtures.

Identification and Speciation of Nanoscale Silver in Complex Solid Matrices by Sequential Extraction Coupled with Inductively Coupled Plasma Optical Emission Spectrometry.

Nanoscale silver (n-Ag) including silver nanoparticles (Ag-NPs), silver chloride nanoparticles (AgCl-NPs), and silver sulfide nanoparticles (Ag2S-NPs) and their corresponding ionic counterpart, namely, dissolved Ag, may coexist in soils. X-ray absorption near edge spectroscopy (XANES) is used to elucidate the speciation of n-Ag in soils, whereas it possesses drawbacks like high costs, rare availability of the instrument, and providing semiquantitative data. We developed a new method for the identification and speciation of n-Ag in soils and sediments based on a sequential extraction technique coupled with inductively coupled plasma optical emission spectrometry. Extraction conditions were first evaluated, establishing the optimal extraction procedure; Ag-NPs, AgCl-NPs, and dissolved Ag in soil were simultaneously extracted by using an aqueous solution of 10 mM tetrasodium pyrophosphate, followed by selective isolation and quantification via AgCl-NPs dissolution (4.45 M aqueous ammonia), centrifugation (Ag-NPs), and detection. The Ag2S-NPs remaining in the soil were then extracted with Na2S solution at pH 7.0 through selective complexation. Optimal recoveries of Ag-NPs, AgCl-NPs, Ag2S-NPs, and dissolved Ag were 99.1 ± 2.4%, 112.0 ± 3.4%, 96.4 ± 4.0%, and 112.2 ± 4.1%, respectively. The method was validated to investigate the speciation of n-Ag in soils and sediments, exhibiting the distribution of Ag-NPs, AgCl-NPs, Ag2S-NPs, and dissolved Ag in each sample, wherein Ag2S-NPs, the major species of n-Ag, accounted for 35.42-68.87% of the total Ag. The results of n-Ag speciation in soil are comparable to those obtained through the linear combination fitting of XANES. This method thus is a powerful, yet convenient, substitute for XANES to understand the speciation of n-Ag in complex solid matrices.

Residue behavior and risk assessment of validamycin a in grape under field conditions.

The dissipation and residue of validamycin A in grapes were investigated under field conditions. An ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for the determination of validamycin A in grapes was established and validated. Methanol and water (90/10, v/v) were used for validamycin A extraction and purification used MCX solid-phase extraction cartridges. The average recoveries of validamycin A in grapes at 0.01, 0.50, and 5.0 mg/kg levels were between 83.8 and 91.4%, with relative standard deviations of 2.3-3.0%. The half-lives of validamycin A in grape were 4.4-6.1 days. The terminal residues in grapes over a range of harvest times (7, 14, and 21 days) were no more than 0.73 mg/kg. According to Chinese consumption data, the risk quotient (RQ) of validamycin A was 3.22%, demonstrating a low risk to consumers. The current study may offer guidance for validamycin A use and could aid the government in determining the maximum residue level (MRL) values for validamycin A in grapes.

Environmentally relevant concentrations of microplastic exhibits negligible impacts on thiacloprid dissipation and enzyme activity in soil.

Microplastics (MPs) as a type of emerging contaminant in the environment have attracted extensive attentions in recent years, and understanding the impacts of MPs on soil biodiversity and functioning are thus increasingly urgent. Nevertheless, few studies were performed to investigate potential effects of MPs on decay of soil organic pollutants in particular pesticides and enzyme activities. Herein, three types of MPs including polystyrene fragments (PS-50) and polyvinyl chloride beads (PVC-42000 and PVC-10) were added to soil at environmentally relevant concentrations (0.2 and 1.0%) to study their impacts on dissipation of thiacloprid and activities of urease, acid phosphatase, invertase and catalase. MPs exhibited negligible impacts on thiacloprid dissipation regardless of MPs type and content, being probably attributed to the unaltered bioavailability of thiacloprid in soil even after an addition of MPs, which was documented by using the hydroxypropyl-ß- cyclodextrin (HPCD) extraction method. Batch sorption experiments also exhibited the comparable adsorption capacity of thiacloprid to soil with and without MPs, along with Kf valuses of 3.44-3.77. Besides, MPs exerted negligible effects on enzyme activities of soil. Taken together, this study showed negligible impacts of MPs at environmentally relevant concentrations on thiacloprid dissipation and enzyme activity, expanding our knowledge on impacts of MPs at the environmentally relevant concentrations on pesticide dissipation in soil.

New Insights into the Stability of Silver Sulfide Nanoparticles in Surface Water: Dissolution through Hypochlorite Oxidation.

Silver sulfide nanoparticles (Ag2SNPs) are considered to be stable in the environment due to the extreme low solubility of Ag2S (Ksp: 6.3 × 10-50). Little is known about the stability of Ag2SNPs in surface water disinfected with aqueous chlorine, one of the globally most used disinfectants. Our results suggested that both uncoated and polyvinylpyrrolidone (PVP)-coated Ag2SNPs (100 µg/L) underwent dissolution in surface water disinfected with aqueous chlorine at a dose of 4 mg/L, showing the highest dissolved silver ion concentrations of 22.3 and 10.5 µg/L within 45 min, respectively. The natural organic matter (NOM) and dissolved oxygen (DO) posed effects on the Ag2SNPs dissolution by chlorine; NOM accelerated Ag2SNPs dissolution while DO reduced the rate and extent of Ag2SNPs dissolution. We further demonstrated that Ag2SNPs dissolution was primarily attributed to active oxidative substances including hydroxyl radical and H2O2 originating from the hypochlorite oxidation. Additionally, water containing Ag2SNPs disinfected with hypochlorite showed stronger interference on the zebra fish (Danio rerio) embryo hatching than Ag2SNPs and hypochlorite on their own. This work documented that Ag2SNPs could undergo dissolution in surface water through hypochlorite oxidation, posing potential risks to aquatic organisms, and therefore showed new insights into the stability of Ag2SNPs in natural environment.

To What Extent Can Full-Scale Wastewater Treatment Plant Effluent Influence the Occurrence of Silver-Based Nanoparticles in Surface Waters?

Silver-based nanoparticles (Ag-b-NPs) emitted by wastewater treatment plants (WWTPs) are considered to be widely present in the natural environment. However, there is much that is unknown about the effect of WWTP effluent on the occurrence of Ag-b-NPs in surface waters. On the basis of field analysis of representative WWTPs in Germany, we demonstrate that more than 96.4% of Ag-b-NPs from wastewater influent are removed through WWTPs, even though influent contains Ag-b-NP concentrations of tens to hundreds ng L(-1), resulting in effluent Ag-b-NP concentrations of 0.7-11.1 ng L(-1) over the seasons. The estimated flux of Ag-b-NPs associated with WWTPs effluent discharge is ∼33 kg y(-1) in Germany. WWTPs effluent increases Ag-b-NP levels of the River Isar to 2.0-8.6 ng L(-1), while remarkable decreases are observed at sites ∼1.5 km downstream of each discharge point, and Ag-b-NP levels then keep stable (0.9-2.3 ng L(-1)) until the next discharge point, showing subtle differences in Ag-b-NP levels between the river and reference lakes without industrial sources and WWTPs effluent discharge. Our results demonstrate that WWTPs effluent can exert a clear influence on the occurrence of Ag-b-NPs in surface waters.

Fabrication and characterization of sodium alginate/blueberry anthocyanins/hinokitiol loaded ZIF-8 nanoparticles composite films with antibacterial activity for monitoring pork freshness.

A smart film was developed to detect the freshness of pork by incorporating blueberry anthocyanins (BAs) and hinokitiol (HIN) loaded zeolite-imidazolium framework (HIN@ZIF-8) with into a sodium alginate matrix, and its microstructure and physicochemical properties were studied. The SA matrix was doped with BAs and HIN@ZIF-8 nanoparticles (SA-BAs/HIN@ZIF-8) to increase its tensile strength and reduce its water vapor permeability. HIN@ZIF-8 has low cytotoxicity, and SA-BAs/HIN@ZIF-8 membranes have long-lasting antimicrobial and highly sensitive color development properties against Escherichia coli and Staphylococcus aureus. The results of pork preservation experiments showed that SA-BA/HIN@ZIF-8 could extend the shelf life of pork to 6 days at 4 ℃. E-nose evaluation experiments showed that SA-BAs/HIN@ZIF-8 could inhibit compounds that cause unpleasant and irritating odours. Therefore, SA-BAs/HIN@ZIF-8 was considered to be an effective method to improve the freshness of pork, and the results showed that it has a promising application in food preservation.

A systemic study of cyenopyrafen in strawberry cultivation system: Efficacy, residue behavior, and impact on honeybees (Apis mellifera L.).

The pesticide application method is one of the important factors affecting its effectiveness and residues, and the risk of pesticides to non-target organisms. To elucidate the effect of application methods on the efficacy and residue of cyenopyrafen, and the toxic effects on pollinators honeybees in strawberry cultivation, the efficacy and residual behavior of cyenopyrafen were investigated using foliar spray and backward leaf spray in field trials. The results showed that the initial deposition of cyenopyrafen using backward leaf spray on target leaves reached 5.06-9.81 mg/kg at the dose of 67.5-101.25 g a.i./ha, which was higher than that using foliar spray (2.62-3.71 mg/kg). The half-lives of cyenopyrafen in leaves for foliar and backward leaf spray was 2.3-3.3 and 5.3-5.9 d, respectively. The residues (10 d) of cyenopyrafen in leaves after backward leaf spray was 1.41-3.02 mg/kg, which was higher than that after foliar spraying (0.25-0.37 mg/kg). It is the main reason for the better efficacy after backward leaf spray. However, the residues (10 d) in strawberry after backward leaf spray and foliar spray was 0.04-0.10 and < 0.01 mg/kg, which were well below the established maximum residue levels of cyenopyrafen in Japan and South Korea for food safety. To further investigate the effects of cyenopyrafen residues after backward leaf spray application on pollinator honeybees, sublethal effects of cyenopyrafen on honeybees were studied. The results indicated a significant inhibition in the detoxification metabolic enzymes of honeybees under continuous exposure of cyenopyrafen (0.54 and 5.4 mg/L) over 8 d. The cyenopyrafen exposure also alters the composition of honeybee gut microbiota, such as increasing the relative abundance of Rhizobiales and decreasing the relative abundance of Acetobacterales. The comprehensive data on cyenopyrafen provide basic theoretical for environmental and ecological risk assessment, while backward leaf spray proved to be effective and safe for strawberry cultivation.

Uptake, accumulation and toxicity of short chain chlorinated paraffins to wheat (Triticum aestivum L.).

Short chain chlorinated paraffins (SCCPs) are ubiquitous persistent organic pollutants. They have been widely detected in plant-based foods and might cause adverse impacts on humans. Nevertheless, uptake and accumulation mechanisms of SCCPs in plants remain unclear. In this study, the soil culture data indicated that SCCPs were strongly absorbed by roots (root concentration factor, RCF>1) yet limited translocated to shoots (translocation factor<1). The uptake mechanism was explored by hydroponic exposure, showing that hydrophobicity and molecular size influenced the root uptake and translocation of SCCPs. RCFs were significantly correlated with logKow values and molecular weights in a parabolic curve relationship. Besides, it was extremely difficult for SCCPs to translocate from shoots back to roots via phloem. An active energy-dependent process was proposed to be involved in the root uptake of SCCPs, which was supported by the uptake inhibition by the low temperature and metabolic inhibitor. Though SCCPs at environmentally relevant concentrations had no negative impacts on root morphology and chlorophyll contents, it caused obvious changes in cellular ultrastructure of root tip cells and induced a significant increase in superoxide dismutase activity. This information may be beneficial to moderate crop contamination by SCCPs, and to remedy soils polluted by SCCPs with plants.

Chiral Nanoclusters as Alternative Therapeutic Strategies to Confront the Health Threat from Antibiotic-Resistant Pathogens.

Pseudomonas aeruginosa (P. aeruginosa), a drug-resistant Gram-negative pathogen, is listed among the "critical" group of pathogens by the World Health Organization urgently needing efficacious antibiotics in the clinics. Nanomaterials especially silver nanoparticles (AgNPs) due to the broad-spectrum antimicrobial activity are tested in antimicrobial therapeutic applications. Pathogens rapidly develop resistance to AgNPs; however, the health threat from antibiotic-resistant pathogens remains challenging. Here we present a strategy to prevent bacterial resistance to silver nanomaterials through imparting chirality to silver nanoclusters (AgNCs). Nonchiral AgNCs with high efficacy against P. aeruginosa causes heritable resistance, as indicated by a 5.4-fold increase in the minimum inhibitory concentration (MIC) after 9 repeated passages. Whole-genome sequencing identifies a Rhs mutation related to the wall of Gram-negative bacteria that possibly causes morphology changes in resistance compared to susceptible P. aeruginosa. Nevertheless, AgNCs with laevorotary chirality (l-AgNCs) induce negligible resistance even after 40 repeated passages and maintain a superior antibacterial efficiency at the MIC. l-AgNCs also show high cytocompatibility; negligible cytotoxicity to mammalian cells including JB6, H460, HEK293, and RAW264.7 is observed even at 30-fold MIC. l-AgNCs thus are examined as an alternative to levofloxacin in vivo, healing wound infections of P. aeruginosa efficaciously. This work provides a potential opportunity to confront the rising threat of antimicrobial resistance by developing chiral nanoclusters.

Dissipation behavior and dietary risk assessment of cyclaniliprole and its metabolite in cabbage under field conditions.

Cyclaniliprole, a novel diamide insecticide, can successfully control Spodoptera litura (Fabricius, 1775) in cabbage. Understanding the residual level of cyclaniliprole in crops and the risk related to its dietary intake is imperative for safe application. Here, we established a simplified, sensitive method for simultaneous analysis of cyclaniliprole and its metabolite NK-1375 (3-bromo-2-((2-bromo-4H-pyrazolo[1,5-d]pyrido[3,2-b]-[1,4]oxazin-4-ylidene)amino)-5-chloro-N-(1-cyclopropylethyl)benzamide) in cabbage by liquid chromatography-tandem mass spectrometry (LC-MS/MS) to investigate their dissipation behavior and residual characteristics. Cyclaniliprole showed rapid dissipation in cabbage and had a half-life of 1.8-2.7 days. The highest residue of total cyclaniliprole (sum of cyclaniliprole and NK-1375) in cabbage from different pre-harvest intervals (3 and 5 days) was 0.25 mg/kg. Our results confirmed the generally low dietary risk quotient of cyclaniliprole (0.243-1.036%) among different age and gender groups in China. Therefore, cyclaniliprole did not pose an unacceptable risk to consumers. This study contributes to setting cyclaniliprole maximum residue limit in cabbage by assessing its dissipation fate and food safety risks.

In vitro assessment of the pesticide bioaccessibility in Dendrobium officinale Kimura et Migo.

Bioaccessibility (BA) is a crucial factor for evaluating the absorption of pollutants in the human digestion system, which is of vital importance for risk assessment of pollutants via food intake. Multi-pesticides were detected in Dendrobium officinale Kimura et Migo (D. officinale), a popular dual-use plant with both botanical medicine and food applications. Nevertheless, the BA of pesticides in D. officinale remains unknown, restricting its market size. Herein, the BA of 19 pesticides with varying properties was evaluated by using an in vitro digestion model, showing BA values between 27.4 and 96.8%. The BA was controlled by the hydrophobicity and water solubility of pesticides, since the significant correlation between these two factors and BA values was observed. Moreover, co-ingested food ingredients could influence the BA, wherein the effect was significant for pesticides of logKow values no less than 3. Lipids enhanced the BA by 9-66%, whereas proteins or carbohydrates decreased BA values by 6-28%. In particular, considering the BA, the risk quotient values were reduced by 3-73%. Clearly, this work suggested that traditional risk assessment without considering the BA would seriously overestimate the actual risk of pesticides in food.

Effect of magnetic field on the accumulation of polyhydroxyalkanoates (PHAs) by microorganism in activated sludge.

The effect of static magnetic field on polyhydroxyalkanoates (PHAs) syntheses by activated sludge under aerobic dynamic feeding (ADF) was evaluated in sequence batch reactors (SBR), with magnetic field intensities of 42, 21, 11 and 7 millitesla (mT) exposure in the feast, feast-famine and famine periods, respectively, and one control group without magnetic field exposure. Under each level of magnetic field intensity, the effect of magnetic field exposed in the famine period to PHAs syntheses was most significant in comparison with that in the feast or feast-famine period. Maximal hydroxybutyrate (HB) and (HV) yield occurred at 21 and 11 mT, respectively, and the minimal yield occurred at 42 mT during exposure in the famine period. The maximum biodegradable rate constant of PHA was noted at 11 mT during exposure in the famine period.

Aggregation, Sedimentation and Dissolution of Cu(OH)2-Nanorods-Based Nanopesticide in Soil Solutions.

Along with the development of nanotechnology, nanomaterials have been gradually applied to agriculture in recent years, such as Cu(OH)2-nanorods-based nanopesticide, an antibacterial agrochemical with a high efficacy. Nevertheless, knowledge about physical stability of Cu(OH)2 nanopesticide in soil solutions is currently scarce, restricting comprehensive understanding of the fate and risk of Cu(OH)2 nanopesticide in the soil environment. Herein we investigated aggregation, sedimentation and dissolution of Cu(OH)2 nanopesticide in soil solutions extracted from three different soil samples, wherein commercial Cu(OH)2 nanopesticide formulation (NPF), as well as its active ingredient (AI) and laboratory-prepared Cu(OH)2 nanorods (NR) with similar morphology as AI, were used as model Cu(OH)2 nanopesticides. We found that NPF compared to AI showed less extents of aggregation in ultrapure water due to the presence of dispersing agent in NPF. Yet, moderated aggregation and sedimentation were observed for Cu(OH)2 nanopesticide irrespective of NPF, AI or NR when soil solutions were used instead of ultrapure water. The sedimentation rate constants of AI and NPF were 0.023 min-1 and 0.010 min-1 in the ultrapure water, whereas the rate constants of 0.003-0.021 min-1 and 0.002-0.007 min-1 were observed for AI and NPF in soil solutions, respectively. Besides aggregation and sedimentation, dissolution of Cu(OH)2 nanopesticide in soil solutions was highly dependent on soil type, wherein pH and organic matter played important roles in dissolution. Although the final concentrations of dissolved copper (1.08-1.37 mg/L) were comparable among different soil solutions incubating 48 mg/L of AI, NPF or NR for 96 h, a gradual increase followed by an equilibrium was only observed in the soil solution from acidic soil (pH 5.16) with the low content of organic matter (1.20 g/kg). This work would shed light on the fate of Cu(OH)2 nanopesticide in the soil environment, which is necessary for risk assessment of the nanomaterials-based agrochemical.

Organochlorine pesticides and other pesticides in peanut oil: Residue level, source, household processing factor and risk assessment.

Peanut oil, edible vegetable oil largely consumed in China, may be polluted with pesticides during both peanut cultivation and processing. In this study, we analyzed organochlorine pesticides, five currently used pesticides and two degradation products, in soils, seeds, peanuts, oil and dregs and systematically tracked variations of their levels in field soils and during the pressing process. The results showed that the application of metolachlor, pirimicarb and quizalofop-p-ethyl pesticides during peanut cultivation caused their concentrations in peanuts to increase. In most samples, the concentration of 3-phenoxybenzoic acid was higher than that of λ-cyhalothrin, and the variation trends of λ-cyhalothrin and 3-phenoxybenzoic acid in soil samples were similar, which indicate that after application, most λ-cyhalothrin may rapidly be degraded to 3-phenoxybenzoic acid. Regarding the pressing process of peanut oil, the sum of mass of oil and shells was less than the mass of the corresponding raw peanut. Compared with that in peanuts, the total mass of most pesticides in oil and shells was lower, while that of two degradation products was higher, an indication that the degradation products were still generated during the pressing process. Finally, the assessment of health risk of different age groups consuming the studied peanuts and peanut oil showed that the risk was very low.

Application value of whole-course health management for patients with nonvalvular atrial fibrillation with oral warfarin treatment.

OBJECTIVE: To explore the effect of the whole-process health management model on the compliance of oral warfarin treatment in patients with non-valvular atrial fibrillation in primary hospitals. METHODS: We retrospectively analyzed the clinical data of 130 patients with non-valvular atrial fibrillation treated in the Department of Cardiovascular Medicine, Hai'an People's Hospital from January 2019 to December 2019. Among them, 63 patients who received routine continuing care were included in the control group, and 67 patients treated with whole-course health management model of primary hospitals were included in the observation group. The two groups were compared in terms of the following parameters: Warfarin anticoagulation knowledge, medication compliance, compliance rate (international normalized ratio, INR) monitoring, bleeding events (gingival bleeding, subcutaneous bleeding, gastrointestinal bleeding, etc.), embolic events (vascular thrombosis), negative emotions before and after management, and patient satisfaction. Logistic analysis was used to analyze independent risk factors affecting the effect of warfarin anticoagulation in patients with non-valvular atrial fibrillation. RESULTS: Compared with the control group, the warfarin anticoagulation knowledge, medication compliance, and INR compliance rate of the observation group were significantly higher, and the incidence of adverse events was significantly lower. Self-rating Anxiety Scale (SAS) and Self-rating Depression Scale (SDS) scores were not significantly different between the two groups before management. After management, SAS and SDS scores decreased significantly in both groups, and were lower in the observation group compared with the control group. The management satisfaction was also significantly higher in the observation group. CONCLUSION: Compared with the conventional continuation care model, the whole-process management in primary hospitals can improve patients' compliance with medical advice and treatment efficacy, with lower risk of bleeding and higher patient satisfaction, providing a better option for the out-of-hospital management of anticoagulation for non-valvular atrial fibrillation patients. Age, hypertension, diabetes, knowledge of warfarin anticoagulation and medication compliance were independent risk factors for the effect of warfarin anticoagulation in patients with non-valvular atrial fibrillation.

Dissipation and dietary exposure risk assessment of pyraclostrobin, fluxapyroxad, difenoconazole, and azoxystrobin in the Fritillaria field ecosystem.

Fritillaria (Beimu in Chinese) is a well-known traditional Chinese medicinal herbal and valuable health food, which has attracted more and more attention. In this study, an efficient method was developed to determine pyraclostrobin, fluxapyroxad, difenoconazole, and azoxystrobin in plants, fresh Fritillaria, dry Fritillaria, and soil via liquid chromatography-tandem mass spectrometry. The average recoveries of the method were 78.9-109.7% with relative standard deviations of 0.94-11.1%. The dissipation half-lives of the four fungicides were 4.4-7.7 days in the Fritillaria plant and 11.6-18.2 days in the soil. The terminal residues of four fungicides were 0.033-0.13 mg/kg in fresh Fritillaria, 0.096-0.42 mg/kg in dry Fritillaria, and 0.12-0.74 mg/kg in soil. In the risk assessment of dietary exposure, all the chronic hazard quotient and acute hazard quotient index values were far below 100%, which were both acceptable to consumers. Accordingly, 7 days was recommended as the pre-harvest interval for the four fungicides in Fritillaria. This work could guide the safe use of these fungicides in Fritillaria and also give a reference for the Chinese government to establish the maximum residue limits (MRLs).

Uptake, translocation and distribution of cyantraniliprole in rice planting system.

While cyantraniliprole has been frequently used in rice fields, knowledge of the uptake, translocation and distribution of cyantraniliprole in rice planting systems is still largely unexplored. Plant uptake is a crucial factor in determining how cyantraniliprole moves through the food chain. Understanding the uptake, translocation and distribution of cyantraniliprole in rice planting system is essential to predicting its accumulation in rice and potential human exposure. Herein, the uptake process of cyantraniliprole in a hydroponic-rice system was systematically investigated. Results showed that cyantraniliprole was easily absorbed by rice roots via a passive diffusion process through the apoplastic pathway and then translocated upward through the xylem, but its acropetal translocation was limited. Cyantraniliprole in shoots can also be downward translocated through the phloem, although only to a limited extent, showing rice plants' weak phloem movement capacity. Furthermore, cyantraniliprole had a short half-life in sediment-water system and dissipated faster in anaerobic than aerobic conditions. At the equilibrium stage of a sediment-water system, cyantraniliprole is preferentially partitioned to the solid phase. Our study provides a systematic insight into the uptake, translocation and distribution of cyantraniliprole in the rice planting system, which is very helpful for better field cyantraniliprole application and environmental risk assessment.

An old story with new insights into an ignored issue of metabolites in biochar-amended soil: Effect of biochar on dissipation of carbosulfan as an example.

Carbofuran (CAS) is one of extensively used carbamate pesticides, which is considered as a derivative or a candidate of carbofuran (CAN) for its lower toxicity and persistence. Nevertheless, CAS could be degraded into its toxic metabolites, imposing potential risks on ecological safety. In this paper, biochars, derived from rice straw (RS), chicken manure (CM), corn straw (CS) and tire rubber (TR), were applied in CAS-contaminated soil to explore their effects on the dissipation of CAS and its metabolites. The dissipation rate of CAS was depressed by the amendment of biochar, mainly because biochar inhibited the hydrolysis of CAS by elevating soil pH value. Nevertheless, CS has efficiently enhanced the dissipation of CAN by almost 2-times for its promotion in hydrolysis and biodegradation. CS and CM improved biodegradation by altering the composition and structure of the microbial communities, exhibiting potential for facilitating bioremediation of CAS and CAN. Moreover, steam activated biochar accelerated the dissipation rate by 1.7-2.9 times and 1.3-2.4 times for CAS and CAN, respectively. This study investigated the effects of biochar on CAS and its toxic metabolites as well as possible governing mechanisms, providing rational instruction for biochar application in ambient atmosphere.