Acute Poisoning among Children Admitted in a Tertiary Care Hospital: A Descriptive Cross-sectional Study.

INTRODUCTION: Acute poisoning is one of the critical causes of hospital admission in children worldwide. Understanding the clinico-demographic profile of childhood poisoning will help in developing targeted prevention strategies. This study aimed to find the prevalence of acute poisoning cases among children admitted to a tertiary care hospital. METHODS: A descriptive cross-sectional study was done among 4972 children admitted in the pediatric ward, High Dependency Care Unit, and Pediatric Intensive Care Unit of a tertiary care hospital in Nepal. The data were collected from the hospital records from over three years between 1 January 2020 and 31 December 2022 after receiving ethical approval from the Institutional Review Committee. A convenience sampling method was used. Data related to the clinical and demographic data were collected from the patients with acute poisoning and analyzed. Point estimate at 95% Confidence Interval was calculated. RESULTS: Out of 4972 paediatric cases admitted to the hospital, acute poisoning was seen in 57 (1.14%) (0.81-1.39, 95% Confidence Interval) patients. Out of these acute poisoning cases, 31 (54.39%) were accidental. The mean age was 10.10±5.40 years with 35 (61.40%) patients from the adolescent age group. CONCLUSIONS: This study conducted in a Nepalese tertiary care hospital identifies acute poisoning as a notable concern among pediatric admissions.

A Portable Electrochemical Biosensor Based on an Amino-Modified Ionic Metal-Organic Framework for the One-Site Detection of Multiple Organophosphorus Pesticides.

Constructing stable, portable sensors and revealing their mechanisms is challenging. Ion metal-organic frameworks (IMOFs) are poised to serve as highly effective electrochemical sensors for detecting organophosphorus pesticides (OPs), leveraging their unique charge properties. In this work, an amino-modified IMOF was constructed and combined with near-field communication (NFC) technology to develop a portable, touchless, and battery-free electrochemical biosensor NH2-IMOF@CS@AChE. -NH2 in NH2-IMOF gives the framework a higher electropositivity compared to IMOF, enhancing the electrostatic attraction with acetylcholinesterase (AChE), which is beneficial for immobilizing AChE. Furthermore, the uncoordinated O atoms and the (CH3)2NH2+ groups in NH2-IMOF help to form stronger bonds with AChE through hydrogen bonds. The results showed a wide linear response range of 1 × 10-15 to 1 × 10-9 M and a low detection limit of 1.24 × 10-13 M for glyphosate (Gly) in the practical detection of OPs. Additionally, electrochemical biosensor arrays were constructed to effectively identify and distinguish multiple OPs on the basis of their unique differential pulse voltammetry (DPV) electrochemical signals. This work provides a simple and effective solution for on-site OP analysis and can be widely applied in food safety and water quality monitoring.

A novel fluorescent sensor for evaluating pH changes in organophosphorus pesticides-treated cells and C. elegans.

pH plays an important role in the evaluation of the healthy status in versatile circumstances. The fluctuation of pH could be affected by complex internal and external stimuli. Especially, the abnormal pH changes is a common characteristic of organophosphorus pesticides (OPs)-caused damage owing to the irreversible inhibition of acetylcholinesterase (AChE) activity. Therefore, the rapid and efficient detection of pH changes is of great significance for predicting the OPs poisoning in living system. However, quick and convenient detecting pH levels in living cells is still limited by the lack of effective chemical tools. Here, a novel fluorescent probe TH-1 based on ESIPT mechanism was synthesized, showing specific fluorescent effects in different pH solutions. Importantly, the AChE catalyzed the hydrolysis product of acetylthiocholine iodide (ATCh) and changed the pH of solution, which influence its fluorescent intensity. Moreover, the probe TH-1 was applied to detecting the pH levels in living cells and C. elegans, providing an efficient chemical sensor for revealing the potential mechanisms of OPs in physiological and pathological processes.

Self-Assembly-Activated Engineered Magnetic Biohybrids Loaded with Phosphotriesterase for Sustainable Decontamination and Detection of Organophosphorus Pesticides.

Phosphotriesterase (PTE) biodegradation of organophosphorus pesticides (OPs) is an efficient and environmentally friendly method. However, the instability and nonreusability of free PTE become the key factors restricting its practical application. In this study, a novel cross-linked magnetic hybrid nanoflower (CLMNF) was prepared. Molecular dynamics (MD) simulations were performed to further investigate the enhanced catalytic efficiency of the enzymes. The recovery rate of enzyme activity was 298% due to the large specific surface area and metal ion activation effect. More importantly, the immobilization scheme greatly improved the stability and reuse performance of the catalyst and simplified the recovery operation. CLMNFs retained 90.32% relative activity after 5 consecutive cycles and maintained 84.8% relative activity after 30 days at 25 °C. It has a good practical application prospect in the degradation and detection of OPs. Consequently, the immobilized enzyme as a biocatalyst has the characteristics of high efficiency, stability, safety, and easy separation, establishing the key step in a biodetoxification system to control organophosphorus contamination in food and the environment.

A Case Presentation in Management of Dysphagia and Dysarthria Caused due to Organophosphorus and Carbamate Insecticide Poisoning.

Organophosphorus and carbamate Insectiside is common in Asia-Pacific region consisting of 63% of the Global death. Organophosphorus and Carbamate poisoning can lead into different complications in the respiratory,digestive,neurological aspects and maybe fatal in certain cases.Besides medical management of the same,early rehabilitation is also required to manage different kinds of neurological aspects caused due to Organophosphorus and carbamate poisoning. The study was done to introspect the early intervention in swallowing and speech therapy in organophosphorus and carbamate poisoning individual,as a part of management besides medical intervention. A 19 years old female reported to the hospital with history of consuming organophos and carbamate insecticide with the intention of self harming causing cardiac arrest and as diagnosed as Flaccid Dysarthria with Oro-Pharyngeal Dysphagia when assessed with diagnostic tools respectively. Early speech and swallowing intervention was provided and introspected using MASA which showed improvement in scores during the therapeutic intervention and was statistically analysed using linear regression analysis. The result showed the improvement in MASA scores (the slope of the best fit) and proved that MASA scores improved significantly (slope = 14.3, p < 0.05) over time as the therapy sessions proceeded. The regression model was also significant (p < 0.05). The motor-speech therapeutic intervention provided improvement in the kinematics of oro-motor skills along with improvement in intelligibility of speech. This study concludes that early intervention in managing speech and swallowing abilities in Dysarthria and Dysphagia is helpful besides medical intervention in such cases.

Sacral neuromodulation for Organophosphate-induced delayed neuropathy neurogenic lower urinary tract dysfunction: a case report.

BACKGROUND: Organophosphate-Induced Delayed Neuropathy (OPIDN) is a rare neurological disorder triggered by exposure to organophosphorus compounds. These compounds exert their neurotoxic effects by impacting the nervous system, leading to systemic manifestations. Urinary system symptoms are infrequently observed in clinical settings. Currently, effective therapeutic interventions for OPIDN-related urinary symptoms are lacking. Sacral nerve modulation therapy, an FDA-approved approach for managing lower urinary tract symptoms, presents as a promising option. Herein, we present a case of OPIDN-induced lower urinary tract obstruction successfully treated with sacral nerve modulation therapy, resulting in substantial symptom relief. CASE REPORT: A 27-year-old male patient presented with severe bilateral hydronephrosis, attributed to low bladder compliance and accompanied by a fever persisting for 6 days. The patient's medical history revealed accidental ingestion of organophosphate pesticide (Dimethoate) with no concomitant underlying diseases. In consideration of the potential for OPIDN, surgical intervention in the form of sacral neuromodulation (phase I) was undertaken. Subsequent evaluation one month post-surgery revealed notable improvements in both bladder compliance and bilateral hydronephrosis, necessitating sacral neuromodulation (phase II). Presently, following a 5-month follow-up period, the patient remains asymptomatic and in favorable health. CONCLUSION: This patient achieved long-term relief using sacral neuromodulation.

Organophosphorus poisoning causing haemorrhagic pancreatitis - a case series.

Organophosphorus, an insecticide used in agricultural and industrial settings, is the most common cause of poisoning in India. Organophosphorus is a nerve poison that causes irreversible inhibition of acetylcholinesterase, which leads to the accumulation of acetylcholine, resulting in excessive cholinergic stimulation of several organ systems. Several complications have been reported, but pancreatitis is quite rare and mainly due to ductal hypertension and injury to parenchyma, consequent to cholinergic hyperactivity in the pancreas. We present a case series of four cases where organophosphorus poisoning was suspected. Autopsy revealed that, in all four cases, the stomach walls were congested, pancreas showed gross haemorrhage over the surface and on cut sections, with other visceral organs showing generalised congestion. Later, after visceral and histopathological examination, all cases were confirmed as organophosphorus (dichlorvos) poisoning with haemorrhagic pancreatitis. Acute pancreatitis in organophosphorus poisoning usually has a subclinical course and gets masked by the systemic effects. Haemorrhagic pancreatitis sequela of acute pancreatitis is a rare and fatal complication of organophosphorus poisoning.

Development of a hydrophilic-lipophilic-balanced copolymer@zirconium-based metal-organic framework-based solid-phase microextraction probe for the trace determination of organophosphorus pesticides in tea infusions.

Organophosphorus pesticides (OPPs) present in tea infusions pose a serious threat to human health. In this study, a sensitive method for the determination of OPPs was developed based on a direct-immersion solid-phase microextraction (DI-SPME) probe. By fine adjustment of the ratio and one-step polymerization of dihydroxy-functionalized zirconium-based metal-organic framework UiO-66-(OH)2 and divinylbenzene-N-vinyl pyrrolidone (DVB-NVP) microspheres, the DVB-NVP@ UiO-66-(OH)2 (D-N@U) composite with an optimal hydrophilic-lipophilic balance (HLB) was achieved. Furthermore, D-N@U was adhesively bonded to stainless-steel wires to fabricate a DI-SPME probe. OPPs, especially those with nonpolar properties characterized by a high octanol-water partition coefficient (log KOW), were selectively and efficiently enriched on the D-N@U-coated DI-SPME probe from tea infusions. Coupled with a gas chromatography-flame photometric detector, the as-fabricated D-N@U-coated DI-SPME probe achieved good performance for OPPs analysis with a wide linear dynamic range of 0.10-500.00 µg/L and low detection limits of 1.96-6.69 ng/L. Moreover, in spiked samples, the recoveries and relative standard deviations were in the ranges of 73.12%-101.20 % and 1.03%-6.56 %, respectively. Owing to its simple operation, high extraction efficiency, and high sensitivity, this approach has great potential for the rapid determination of multiple pesticide trace-level residues in food.

Nanozyme coating-gated multifunctional COF composite based dual-ratio enhanced dual-mode sensor for highly sensitive and reliable detection of organophosphorus pesticides in real samples.

The reliable detection of organophosphorus pesticides (OPs) in complex matrices remains an enormous challenge due to inevitable interference of sample matrices and testing factors. To address this issue, we designed a nanozyme-coated mesoporous COF with guest molecule loading, and successfully used it to construct a dual-ratio dual-mode sensor through target-regulated signal generation. The multifunctional COF-based composite (MB/COF@MnO2, MCM) featured high loading of methylene blue (MB), oxidase-like MnO2 coatings as gatekeepers, and specific recognition of thiocholine (TCh). TCh, a regulator produced from acetylcholinesterase (AChE)-catalyzed hydrolysis of acetylthiocholine, could decompose MnO2 coatings, triggering the release of abundant MB and oxidation of few o-phenylenediamine (OPD). OPs, strong inhibitors of AChE, could restrain TCh production and MnO2 decomposition, thereby controlling the release of less MB and oxidation of more OPD. This regulation boosted the dual-ratio dual-mode assay of OPs by using the released MB and oxidized OPD in the solution as testing signals, measured by both fluorescent and electrochemical methods. Experimental results demonstrated the sensitive detection of dichlorvos with LODs of 0.083 and 0.026 ng/mL via the fluorescent/electrochemical mode, respectively. This study represented a creative endeavor to develop dual-ratio dual-mode sensors for OPs detection in complex samples, offering high sensitivity, excellent selectivity, and good reliability.

Fe3O4@nitrogen-doped carbon@Pd core-double shell nanotubes as a novel nanosorbent for ultrasonic assisted dispersive magnetic solid phase extraction of organophosphorus pesticides.

In this study, an ultrasonic assisted dispersive magnetic solid phase extraction leveraging Fe3O4@nitrogen-doped carbon@Pd core-double shell nanotubes was developed for the extraction of organophosphorus pesticides (OPPs) in trace levels from real samples. Incorporation of Pd species into the structure of the nanosorbent could enhance its interactions with sulfur groups in the structure of OPPs. X-ray photoelectron spectroscopy and X-ray diffraction, brunauer-emmett-teller, field emission scanning electron microscopy, and high-resolution transmission electron microscopy were used to characterize the nanosorbent after its synthesis. Then, effective variables on the extraction efficiency of OPPs using the nanosorbent were optimized. These parameters included 2-propanol as the adsorption solvent; the sample pH of 7.0; the sorbent quantity of 10 mg; and the extraction and desorption times of 3 min. Under optimized conditions, linear ranges with determination coefficients (R2) higher than 0.99, low detection limits of 0.30 ng mL-1, high preconcentration factors (423-470) and relatively high extraction recoveries (84-94 %) were obtained. The proposed extraction system was then successfully applied to the analysis of OPPs in fruits, vegetables, water, and agricultural soil samples, yielding relative recoveries from 90.4 to 107 %.

Alcohol-based hydrophobic deep eutectic solvents and ultrasound-assisted liquid phase microextraction followed by GC-MS for the extraction and analysis of organophosphorus pesticides in the blood of farmers.

Organophosphorus pesticides (OPPs) are a group of pesticides that are most widely used in the agricultural sector, and farmers are exposed to these chemicals more than other members of society. In this work, an environmentally friendly, simple, and safe ultrasound-assisted dispersive liquid-liquid microextraction (USA-DLLME) method using alcohol-based hydrophobic deep eutectic solvents (HDESs) followed by gas chromatography-mass spectroscopy (GC-MS) was developed for the extraction and determination of OPPs in the blood of farmers studied in Ravansar cohort. DESs synthesized from thymol as hydrogen bond donor (HBD) and aliphatic alcohols as hydrogen bond acceptor (HBA) have been used as extractants. Under optimal experimental conditions, the reproducibility of the method based on 7 replicate measurements of 10 µg L-1 of OPPs in blood samples was in the range of 1.4-3.8%. The method showed a linearity in the range of 0.01-150 µg L-1. The limits of detection and limits of quantification were between 0.003 and 0.02 µg L-1 and 0.01-0.05 µg L-1, respectively. The matrix effect and accuracy of the method were confirmed by spiking different amounts of OPPs in real blood samples and obtaining relative recoveries in the range of 91-112%. The results showed that the concentration of OPPs in the case group was significantly higher than in the control group, which is because the case group was exposed to OPPs during the spraying of agricultural products.

[An analysis of 4695 acute poisoning cases in Tianjin-Heibei from 2020-2022].

Objective: To study and analyze the epidemiological regularity of acute poisoning in Tianjin-Hebei region from 2020 to 2022, and to provide reference for the treatment and prevention of related patients. Methods: In December 2023, the analysis results and clinical data of 4695 patients with drug poisoning from January 2020 to December 2022 in multiple centers of Tianjin-Hebei region were collected as research objects. Gender, age, type of drug poisoning, season and poisoning route of the research objects were analyzed, and statistical analysis was conducted as well. Results: The sex ratio of men and women was 1∶1.16 (2173/2522). The poisoning of antidepressants and benzodiazepines were the most common drug poisonings, accounting for 1550 and 1274 cases respectively (33%, 27.1%). Paraquat poisoning has decreased year by year, while the poisonings of herbicides with low toxicity such as diquat, glyphosate and cremart have increased. The number of cases reached a peak during May to August which was the poisoning season, while was relatively fewer during October to December. Conclusion: Effective intervention measures should be taken according to the age of high incidence of poisoning, different seasons and populations. Essential drug poisoning prevention measures should be established and improved. The systems of sedative drug management and use should be established, and pesticide management and storage need to be strengthened.

Rapid and efficient removal of organophosphorus pollutant and recovery of valuable elements: A boosted strategy for eliminating organophosphorus from wastewater.

Considering the significant hazards of organophosphorus compounds (OPs) and the potential crisis of phosphorus (P) resource shortage, there is a great necessity to develop economically feasible, highly effective, and sustainable strategies to remove OPs and recover P resources. In this study, low-cost microscale zero-valent iron (mZVI) was used to activate hydrogen peroxide for the rapid and efficient elimination of Tetrakis(hydroxymethyl)phosphonium sulfate (THPS) from the aquatic environment. Compared to the conventional Fenton reaction and commercial mZVI, mZVI/H2O2-based Fenton-like reaction exhibited superior removal performance for THPS. The removal mechanism of the mZVI/H2O2 system for THPS was thoroughly elucidated through the identification of reactive oxygen species, characterization analysis, and theoretical calculation. Furthermore, the valuable components of the degradation products were successfully recovered through thermally induced precipitation of the sample followed by high-temperature calcination. The mZVI/H2O2 system has demonstrated significant advantages in removing organic compounds from various types of actual wastewater and improving the biodegradability of the wastewater. This study presented an environmentally friendly and highly efficient strategy to eliminate OPs pollution and recover P resources. It also provided an easy-to-operate method for remediating actual industrial wastewater.

Tuning the Properties of Polyvinylidene Fluoride/Alkali Lignin Membranes to Develop a Biocatalytic Membrane Reactor for an Organophosphorus Pesticide Degradation.

It has been observed that the immobilization of a phosphotriesterase enzyme (PTE) onto polyvinylidene fluoride (PVDF) membranes significantly decreased the enzyme activity, and this negative effect was attributed to the hydrophobic character of the membrane. The indirect indication of this reason was that the same enzyme immobilized on other membrane materials bearing hydrophilic character showed better performance. In this work, we provide direct evidence of the mechanism by immobilizing a PTE on a PVDF membrane hydrophilized by blending it with alkali lignin (AL). The PTE was immobilized on PVDF membrane by a covalent bond with the same procedure used in earlier studies to attribute changes in enzyme activity solely to the wettability properties (and not to the material chemistry). The activity of the PTE immobilized on the PVDF membrane hydrophilized with AL was 50% higher than that of the enzyme immobilized on the PVDF hydrophobic membrane. Further improvements of the membrane structure tailored for the development of a biocatalytic membrane reactor (BMR) were also promoted. In particular, the performance of the BMR was studied as a function of the thickness of the membrane, which allowed us to modulate the residence time into the enzyme-loaded membrane pores while maintaining the flow rate through the pores at a constant.

Electrochemiluminescence sensor for organophosphorus pesticides based on the regulation of resonance energy transfer between negative charged gold nanorods and Ru(bpy)32.

Combined the electrostatic interaction of the negatively charged gold nanorods (AuNRs) (as acceptor) and Ru(bpy)32+ (as donor), an electrochemiluminescence resonance energy transfer (ECL-RET) sensor was constructed and applied for the detection of organophosphorus pesticides (OPs). Negatively charged AuNRs were synthesized by modifying AuNRs with polystyrene sulfonate (PSS) firstly, which can bind to Ru(bpy)32+ through electrostatic interaction so that the luminophore was absorbed by the acceptor, the resonance energy transfer occurred and only low ECL signal had been detected. Thiocholine can be produced by the hydrolysis process of acetylthiocholine (ATCh) with the help of acetylcholinesterase (AChE), which can bond with PSS-modified AuNRs (PSS-AuNRs) through gold-sulfur interaction, this caused the releasing of the adsorbed Ru(bpy)32+ into the solution and resulting in the restoration of the ECL intensity. However, the activity of AChE was inhibited by OPs, and the recovery process of the ECL signal was thus suppressed as well. In this study, chlorpyrifos was chosen as model target, the results indicated that the correlation between the ECL intensity and the logarithm of chlorpyrifos concentration showed remarkable linearity across 1 ng/mL to 1 mg/mL, achieving a detection limit of 0.51 ng/mL. The proposed system has been utilized for detecting OPs in real samples with satisfied results.

Natural deep eutectic solvent-based dispersive liquid-liquid microextraction of pesticides in drinking waters combined with GC-MS/MS detection.

The current research aims to develop a new analytical method applying a dispersive liquid-liquid microextraction (DLLME) assisted by vortex and using an environmentally friendly extractant for the preconcentration of organochlorine and organophosphorus pesticides followed by gas chromatography-tandem mass spectrometry (GC-MS/MS) analysis. The extractant (i.e., natural deep eutectic solvent (NADES)) is safe, cheap, biodegradable and can be prepared by simply mixing DL-menthol and decanoic acid (molar ratio 2:1). The main experimental factors affecting the extraction of all analytes evaluated (19 organochlorine and organophosphorus pesticides) have been optimised using a multivariate analysis consisting in two steps: a Plackett-Burman design followed by a central composite design (CCD). Seven experimental factors have been evaluated: (i) sample volume; (ii) NADES volume; (iii) sample pH; (iv) extraction time; (v) centrifugation time; (vi) centrifugation speed; and (vii) ionic strength (NaCl %, w v-1). For the significant variables, the optimum values were 10 mL sample and 45 µL NADES. No pH adjustment as well as addition of NaCl were needed. The other variables were set at 3 min extraction time, 5 min centrifugation time and 900×g centrifugation speed, respectively. Under the optimised extraction conditions, the limit of quantification (LOQ) values ranged between 0.2 and 78 ng L-1 for all analysed pesticides. Furthermore, the proposed analytical method has been successfully applied to drinking water (bottled spring water). The recovery study (n = 3) has been evaluated at 0.1, 1.0 and 5.0 µg L-1 spiking levels, obtaining relative recovery values within the range of 70 % and 117 % and RSD values between 1 % and 20 % for all the analytes studied, except for p,p-DDT (56-77 % in high conductivity water samples).

Molecular interaction mechanisms on (-)-epigallocatechin-3-gallate improving activities of inhibited acetylcholinesterase by selected organophosphorus pesticides in vitro & vivo.

(-)-Epigallocatechin-3-gallate (EGCG) is reported to have benefits for the treatment of Alzheimer's disease by binding with acetylcholinesterase (AChE) to enhance the cholinergic neurotransmission. Organophosphorus pesticides (OPs) inhibited AChE and damaged the nervous system. This study investigated the combined effects of EGCG and OPs on AChE activities in vitro & vivo. The results indicated that EGCG significantly reversed the inhibition of AChE caused by OPs. In vitro, EGCG reactived AChE in three group tubes incubated for 110 min, and in vivo, it increased the relative activities of AChE from less than 20% to over 70% in brain and vertebral of zebrafish during the exposure of 34 h. The study also proposed the molecular interaction mechanisms through the reactive kinetics and computational analyses of density functional theory, molecular docking, and dynamic modeling. These analyses suggested that EGCG occupied the key residues, preventing OPs from binding to the catalytic center of AChE, and interfering with the initial affinity of OPs to the central active site. Hydrogen bonding, conjugation, and steric interactions were identified as playing important roles in the molecular interactions. The work suggests that EGCG antagonized the inhibitions of OPs on AChE activities and potentially offered the neuroprotection against the induced damage.

Enhanced retention of hydrophobic pesticides in subsurface soils using organic amendments.

The rapid global population growth since the early 2000s has significantly increased the demand for agricultural products, leading to widespread pesticide use, particularly organophosphorus pesticides (OPPs). This extensive application poses severe environmental risks by contaminating air, soil, and water resources. To protect groundwater quality, it is crucial to understand the transport and fate of these pesticides in soil and sediment. This study investigates the effects of hydrochars and biochars derived from sugar beet shreds (SBS) and Miscanthus×giganteus (MIS) on the retardation and biodegradation of OPPs in alluvial Danube sandy soil. The research is novel in its approach, isolating native OPP-degrading bacteria from natural alluvial sandy soil, inoculating them onto chars, and reapplying these bioaugmented chars to the same soil to enhance biodegradation and reduce pesticide leaching. The amendment of chars with immobilized Bacillus megaterium BD5 significantly increased bacterial abundance and activity. Metabarcoding of the 16S rRNA gene revealed a dominance of Proteobacteria (48.0-84.8 %) and Firmicutes (8.3-35.6 %). Transport modeling showed retardation coefficients (Rd) for OPPs ranging from 10 to 350, with biodegradation rates varying between 0.05 % and 75 %, indicating a positive correlation between retardation and biodegradation. The detection of biodegradation byproducts, including derivatives of phosphin, pyridine, and pyrazole, in the column leachate confirmed that biodegradation had occurred. Additionally, principal component analysis (PCA) revealed positive correlations among retardation, biodegradation, specific surface area (SSA), aldehyde/ketone groups, and bacterial count. These findings demonstrate the potential of biochar and hydrochar amendments to enhance OPP immobilization in contaminated soils, thereby reducing their leaching into groundwater. This study offers a comprehensive approach to the remediation of pesticide-contaminated soils, advancing both our fundamental understanding and the practical applications of environmental remediation techniques.

Cytotoxicity evaluation of organophosphorus flame retardants using electrochemical biosensors and elucidation of associated toxic mechanisms.

In recent years, organophosphorus flame retardants (OPFRs) have been widely used as substitutes for brominated flame retardants with excellent properties, and their initial toxicological effects on the water ecosystem and human health have gradually emerged. However, to date, research on the cytotoxicity and health risks of OPFRs is still limited. Therefore, this study aims to systematically explore the cytotoxic effects and toxic mechanisms of OPFRs on cells. Human liver cancer (HepG2) cells were adopted as an ideal model for toxicity evaluation due to their rapid growth and metabolism. This study proposes a sensitive electrochemical cell-based sensor constructed on a graphitized multi-walled carbon nanotube/ionic liquid/gold nanoparticle-modified electrode. The sensor was used to detect the cytotoxicity of tri(2-butylxyethyl) phosphate (TBEP), tributyl phosphate (TnBP), triphenyl phosphate (TPhP), tri(1,3-dichloro-2-propyl) phosphate (TDCIPP), tri(2-chloropropyl) phosphate (TCPP) and tri(2-chloroethyl) phosphate (TCEP) in the liquid medium, providing insight into their toxicity in water environments. The half-maximal inhibitory concentration (IC50) of TBEP, TnBP, TPhP, TDCIPP, TCPP and TCEP on HepG2 cells were 179.4, 194.9, 219.8, 339.4, 511.8 and 859.0 µM, respectively. Additionally, the cytotoxic mechanism of six OPFRs was discussed from the perspective of oxidative stress and apoptosis, and four indexes were correlated with toxicity. Furthermore, transcriptome sequencing was conducted, followed by a thorough analysis of the obtained sequencing results. This analysis demonstrated a significant enrichment of the p53 and PPAR pathways, both of which are closely associated with oxidative stress and apoptosis. This study presents a simplified and efficient technique for conducting in vitro toxicity studies on organophosphorus flame retardants in a water environment. Moreover, it establishes a scientific foundation for further investigation into the mechanisms of cytotoxicity associated with these compounds.

UV-activated calcium peroxide system enables simultaneous organophosphorus degradation, phosphate recovery, and carbon fixation.

Advanced oxidation processes are a desirable technology for treatment of contaminants of emerging concern. Nevertheless, conventional advanced oxidation of organophosphorus compounds releases inorganic phosphate, posing downstream concerns related to eutrophication. For this reason, we evaluated the ultraviolet light-activated calcium peroxide (UV/CaO2) system for effective treatment of organophosphorus compounds and concurrent capture of the mineralization products, phosphate. The degradation mechanisms, reaction kinetics, and mineralizations were assessed to determine the overall efficiency and performance of the UV/CaO2 process. Knowledge gaps related to photocatalysis in the UV/CaO2 system were not only addressed, but also leveraged to identify unique advantages for removal of organophosphorus compounds and their degradation products. Experimental results confirmed that the UV/CaO2 system effectively mineralized organophosphorus compounds and recovered inorganic phosphate; additionally, collaborative carbon fixation performance of the system reveals the potential of carbon utilization. These outcomes were facilitated by the alkaline environment generated by CaO2. The recovered solids contained most of the phosphorus and carbon from the parent compounds. Ultimately, these findings provide transformative, new insights into the development and application of advanced oxidation processes that prevent downstream concerns related to mineralization products, especially inorganic phosphorus and carbon.