Dimethyl Phosphate Research Articles

Facile Recycling Strategy of Dyed Polyester Waste by Template-Based Synthesis of UiO-66 for Value-Added Transformation into Self-detoxifying Fabrics.

Polyethylene terephthalate (PET) accounts for a significant portion of textile waste, and recycling strategies for this material have attracted much attention. This study proposes a facile and innovative PET recycling method applicable to environmental remediation that involves the conversion of dyed PET fabric waste into a value-added fabric. Herein, a template-based synthesis approach capable of growing a UiO-66 metal-organic framework (MOF) directly on a dyed PET fabric is reported. The advantage of this process lies in its simplicity, where the partial hydrolysis of PET followed by a zirconium chloride treatment results in the successful growth of UiO-66 on a dyed PET fabric with the concurrent removal of the dye without additional steps. The catalytic performance of the UiO-66-grown fabric was evaluated through the degradation of dimethyl 4-nitrophenyl phosphate (DMNP), a nerve agent simulant. The fabric produced by the simple metal treatment (Zr@PEThyd) exhibited excellent DMNP degradation performance with t1/2 = 43.3 min and maintained functional stability after a harsh washing procedure, an outcome attributed to the surface-assisted UiO-66 growth that ensured good bonding stability. The developed process is innovative in that it uses dyed PET waste as a template for the direct growth of UiO-66, simplifying the process without compromising the catalytic functionality. This research provides an informative option for a sustainable textile recycling strategy by transforming dyed PET waste into an advanced self-detoxifying material.

Ion-Induced PIP2 Clustering with Martini3: Modification of Phosphate-Ion Interactions and Comparison with CHARMM36.

Phosphatidylinositol 4,5-bisphosphate (PIP2) is a critical lipid for cellular signaling. The specific phosphorylation of the inositol ring controls protein binding as well as clustering behavior. Two popular models to describe ion-mediated clustering of PIP2 are Martini3 (M3) and CHARMM36 (C36). Molecular dynamics simulations of PIP2-containing bilayers in solutions of potassium chloride, sodium chloride, and calcium chloride, and at two different resolutions are performed to understand the aggregation and the model parameters that drive it. The average M3 clusters of PIP2 in bilayers of 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine and PIP2 bilayers in the presence of K+, Na+, or Ca2+ contained 2.2, 2.6, and 6.4 times more PIP2 than C36 clusters, respectively. Indeed, the Ca2+-containing systems often formed a single large aggregate. Reparametrization of the M3 ion-phosphate Lennard-Jones interaction energies to reproduce experimental osmotic pressure of sodium dimethyl phosphate (DMP), K[DMP], and Ca[DMP]2 solutions, the same experimental target as C36, yielded comparably sized PIP2 clusters for the two models. Furthermore, C36 and the modified M3 predict similar saturation of the phosphate groups with increasing Ca2+, although the coarse-grained model does not capture the cooperativity between K+ and Ca2+. This characterization of the M3 behavior in the presence of monovalent and divalent ions lays a foundation to study cation/protein/PIP2 clustering.

In-situ adsorption and detoxification of chemical warfare agent simulants by biocompatible Zr-MOFs immobilized ionic liquids composites: Mechanisms, degradation pathways and DFT calculations

Detoxicating materials of chemical warfare agents (CWAs) and their simulants play a critical role in reducing pollution contamination and environmental renovation. In this work, we present a simple strategy to prepare a core–shell structure Fe3O4/UiO-66-NH2/ILs@mSiO2 using hydrogen bonding association and electrostatic forces. We performed disinfection studies on dimethyl 4-nitrophenyl phosphate (DMNP) and 2-chloroethyl ethyl sulfide (2-CEES). The synergistic effects of catalytic activations for CWAs, which reduce the electron transport distance and lower the reaction energy barrier, lead to an increase in hydrolysis and Fenton-like reactions efficiency. Eliminationing tests of DMNP and 2-CEES showed that the half-lives of the degradation reactions were 128.36 and 1.12 min, respectively, and the degradation efficiency did not decrease significantly after 4 cycles. This new type of structure could be magnetically separated within 60 s to facilitate material recovery and reuse. Moreover, the presence of a mesoporous silica shell made the catalyst particles to become biocompatible and environmentally friendly. The degradation pathways of the intermediates were revealed based on nuclear magnetic resonance spectroscopy (NMR), gaschromatography-mass spectrometry (GC–MS) and density functional theory (DFT) calculations. The effective combination of catalysts provided a facile strategy for developing multi-effect synergistic catalysts for the elimination of CWAs and other pollutants.

Enhancing the degradation efficiency of dimethyl nitrophenyl Phosphate, a chemical warfare agent Simulant, through acid sites in bimetallic Metal-Organic framework Ti-MOF-808(Zr): Synergistic roles of Lewis and Brønsted acids

Nerve agents pose an immediate and severe threat to human health, emphasizing the critical need for catalysts that can rapidly and effectively degrade these agents. Herein, we synthesized Ti-MOF-808(Zr) materials with varying Ti/Zr molar ratio using microwave-assisted solvothermal method. Characterization techniques, including BET analysis, TEM, and TG-DTA, confirmed their outstanding properties, such as a high surface area (1756 m2/g), 100 nm particle size, cubic shape, and remarkable thermal stability exceeding 500 °C. The coexistence of Ti4+ and Zr4+ in the secondary building units or inorganic nodes significantly elevates the number of Lewis and Brønsted acid sites in the bimetallic Ti-MOF-808(Zr), as determined through the TPD-NH3 and FTIR-CD3CN methods. We harnessed the potential of MOF-808(Zr) and Ti-MOF-808(Zr) materials as catalysts for the swift degradation of dimethyl nitrophenyl phosphate (DMNP). Remarkably, 4 %Ti-MOF-808(Zr) could degrade DMNP with a half-life of 14.95 s, achieving a complete degradation time within 80 s. We conducted a comprehensive investigation into various factors affecting the DMNP degradation process, including the Ti/Zr molar ratio, catalyst mass, pH, and buffer solution concentration. Notably, our findings reveal that the efficiency of DMNP degradation is profoundly influenced by both the total number of Lewis acid sites and the average acid sites ratio.

MOF-Enabled Electrochemical Sensor for Rapid and Robust Sensing of V-Series Nerve Agents at Low Concentrations.

Among nerve agents, V-series nerve agents are some of the most toxic, making low-concentration detection critical for the protection of individuals, populations, and strategic resources. Electrochemical sensors are ideally suited for the real-time and in-field sensing of these agents. While V-series nerve agents are inherently nonelectroactive, they can be hydrolyzed to electroactive products compatible with electrochemical sensing. Zr(IV) MOFs are next-generation nanoporous materials that have been shown to rapidly catalyze the hydrolysis of nerve agents. This work makes use of these nanomaterials to develop, for the first time, an MOF-enabled electrochemical sensor for V-series nerve agents. Our work demonstrates that the VX thiol hydrolysis product can be electrochemically detected at low concentrations using commercially available gold electrodes. We demonstrate that low-concentration thiol oxidation is an irreversible reaction that is dependent on both mass transport and adsorption. Demeton-S-methylsulfon, a VX simulant, is used to demonstrate the full range of sensor operation that includes hydrolysis and electrochemical detection. We demonstrate that MOF-808 rapidly, selectively, and completely hydrolyzes demeton-S-methylsulfon to less-hazardous dimethyl phosphate and 2-ethylsulfonylethanethiol. Low-concentration measurements of 2-ethylsulfonylethanethiol are performed by using electrochemical techniques. This sensor has a limit of detection of 30 nM or 7.87 μg/L for 2-ethylsulfonylethanethiol, which is near the nerve agent exposure limit for water samples established by the United States military. Our work demonstrates the feasibility of rapid, robust electrochemical sensing of V-series nerve agents at low concentrations for in-field applications.

Flame retardancy in isotactic polypropylene modified with crystalline coordination polymers based on calcium, zinc or aluminum dimethyl phosphates

A novel variety of metal organophosphates (MOPs) coordination polymers: calcium bis(dimethyl phosphate) (CaDMP), zinc bis(dimethyl phosphate) (ZnDMP) and aluminum tris(dimethyl phosphate) was examined for the first time to act as potential flame retardants in isotactic polypropylene (iPP) materials and their flame-retarding activity compared with widely used commercial flame retarder ammonium polyphosphate (APP). All iPP composites containing 20 wt. % of MOPs as with APP achieve V-2 in the UL-94 test and LOI values even higher (25.5 vol. % for iPP/20 %CaDMP) than determined for APP-containing material accompanied by maintaining or slightly degrading mechanical properties. Also in mass loss calorimeter test (MLC) the MOPs demonstrated a positive effect on the fire response of the obtained composites leading to a reduced, in the case of ZnDMP, the peak of heat release rate (pHRR), total heat evolved (THE), average effective heat of combustion (avEHC), fire growth rate (FIGRA) by 57 %, 35 %, 29 %, 63 % respectively when compared with pure iPP. Moreover the detailed analysis of the solid and liquid pyrolysis products of MOPs was done via FTIR. The FTIR spectra and PRXD studies of the char residues after combustion indicated the formation of a solid, inorganic condensed phosphates and release of trimethyl phosphate (TMP) into the gas phase. Finally, the flame retardancy mechanism of MOPs was proposed based on results of MLC test and of the pyrolysis experiment. The gas phase activity of all three MOPs was confirmed by the decrease of avEHC most probably due to release of trimethyl phosphate (TMP) into flame, whereas, in particular ZnDMP acted strongly in the condensed phase by forming a intumescent, protective layer.

A facile surface phosphorylation grafting strategy to fabricate durable flame-retardant wool fabric

Inspired by the phosphorylation of amino acids, a facile surface grafting approach with dimethyl phosphate (DMP) was developed to endow durable flame retardancy to wool fabrics. The grafting behavior between DMP and wool fibers was investigated by ATR-FTIR analysis and XPS spectroscopy. After undergoing the grafting modification process, the flame-retardant ability of the grafted sample was clearly enhanced, with an increase in the limiting oxygen index (LOI) value from 23.8 % to 30.5 %. Even after 25 washing cycles, it still retained 27.0 %. Meanwhile, cone-calorimeter tests (CCT) demonstrated that the grafted wool fabric achieved a peak heat release rate that decreased by 28.1 % and total heat release decreased by 19.2 %. The grafted wool fabric also showed better thermal stability, with T50% increased from 370 °C to 397 °C (N2 atmosphere), 408 °C to 439 °C (air atmosphere). Char residues had a large increase, from 0.6 % to 21.8 % (air atmosphere), during a thermogravimetric (TG) test. Moreover, char residue analysis confirmed that the introduced phosphorylated structure could assist the wool fabrics to form intensive, expanded protective char residue after exposure to flame, protecting the matrix from decomposition. In this work, we provide a facile strategy for fabricating durable flame-retardant (FR) wool fabrics under a low temperature.

A MOF-doped molecularly imprinted polymer/MOF hybrid gel incorporating with pH-buffering sodium acrylate for practical detoxification of organophosphorus nerve agents

The fatal toxicity of organophosphorus nerve agents (ONAs) and the realistic condition of chemical attack occurring place trigger the urgent need to develop catalyst materials with degrading ability under the natural environment without bulk water and bases. Here, we strategically design a molecularly imprinted polymer (MIP)/MOF hybrid catalyst material by integrating enzyme-mimic MIP with Zr-MOF UiO-66-NH2 which demonstrate promising catalytic performance for degradation of ONAs. Furthermore, sodium acrylate functions as a hydrophilic and alkaline functional unit together with pyridine-amidoxime based functional monomers (PAAO) to copolymerize into molecularly imprinted polymeric network. The basic sodium carboxylate groups were installed near the active sites to provide appropriate alkaline microenvironment, non-bulk water and acid buffer capacity for the catalysis in pure water. The resultant MIP/MOF composite catalyst demonstrate outstanding catalytic activities in both liquid and solid phase hydrolysis of ONAs. Specifically, the half-life of liquid phase hydrolysis catalyzed by MIP/UiO-66-NH2-0.5 achieves 9.4 min for diethyl-4-nitrophenyl phosphate (DENP) and 10 min for dimethyl 4-nitrophenyl phosphate (DMNP), and solid-state hydrolysis present rapid degradation efficiency with a half-life of 28.6 min. In addition, composite catalyst MIP-Ag/UiO-66-NH2-0.5 that retains substrate selectivity of MIP, enables the simultaneous degradation of two types of organophosphorus substrates (phosphate and thiophosphate) by MIP and MOF in a synergistic way. Summarily, this work displays promising potential of MIP/MOF hybrid enzyme-like catalyst as effective and practical material for the practical protection and detoxification of organophosphorus nerve agents.

Are nitrification inhibitors effective in reducing N2O from farm-scale emission hotspots?

Livestock congregation areas are nitrous oxide (N2O) hot-spots and could be key areas to focus mitigation action. We tested whether combined cattle urine and fertiliser N2O-N emission factors (EFs) would be higher from a farm gateway area compared to a standard pasture under sub-tropical conditions, and whether the nitrification inhibitor, dimethyl pyrazole phosphate (DMPP), would lower N2O EFs from the gateway area. Treatments (n = 3) included: (i) fertiliser applied to a standard pasture (50 kg urea-N ha−1), (ii) fertiliser (50 kg urea-N ha−1) + urine (350 kg N ha−1) applied to a standard pasture, (iii) fertiliser (50 kg urea-N ha−1) + urine (350 kg N ha−1) applied to the gateway area, and (iv) fertiliser (50 kg urea-N ha−1) + urine (350 kg N ha−1) + DMPP (1.5 kg ha−1) applied to the gateway area. Emissions were monitored via an automated static chamber-based system and 15N-labelled urine treatments (n = 4) used to assess N2O + N2 emissions, N2O:N2 and 15N recovery from the pasture. No significant differences (p > 0.05) were observed for EFs between the fertiliser + urine treatment for the standard pasture (1.10 ± 0.17%) or the gateway area (1.46 ± 0.40%). DMPP did not lower the N2O-N EF from the gateway area (1.50 ± 0.22%), where wet and warm conditions may have accelerated DMPP degradation. In the 15N-labelled urine treatments, significantly (p < 0.05) greater N2O + N2 emissions occurred in the gateway compared to the standard pasture, but disaggregating EFs between the contrasting areas was not warranted.

ANALYSIS OF THE COMPOSITION OF TWO LOCALLY MANUFACTURED PESTICIDES USED BY FISH TRADERS IN UYO, NIGERIA.

The use of locally made chemical pesticides often exerts deleterious effects on man and his environment. In recent times, there has been an observed increase in the indiscriminate use of locally made chemical pesticides for the protection of food materials including fishes in Uyo metropolis. As a result, it has become necessary to analyze the composition of some locally made pesticides used by fish traders in Uyo metropolis, Akwa Ibom state, Nigeria. Test pesticides (“Diamond Knockdown” and “Best Fighter”) were purchased from traders in Uyo. The pesticides were subjected to physico-chemical, chemical composition and heavy metal analysis using High Performance Liquid Chromatography (HPLC), Mass Spectrometry (MS) and Atomic Absorption spectrophotometer. The two pesticides were found to be acidic, with a pH value of 3.6 for “Diamond Knockdown” and 3.8 for “Best Fighter”. Formaldehyde, isopropyl alcohol, camphor, dichlorvos (2,2-dichlorovinyl dimethyl phosphate) and naphthalene were detected in both pesticides. However, “Diamond Knockdown” had I-hexene as one of the chemical constituents but it was not found in “Best Fighter” while Xylene was detected in “Best Fighter” but was absent in “Diamond Knockdown”. Dichlorvos had the highest chemical concentration for the two pesticides while formaldehyde had the lowest. Chromium, cadmium, mercury and lead were the heavy metals detected in concentrations of 0.012, 0.205, &lt;0.001 and &lt;0.001mg/l respectively for “Diamond Knockdown” while “Best Fighter” had 0.019, 0.039, &lt;0.001 and &lt;0.001mg/l concentrations respectively for chromium, cadmium, mercury and lead. The concentration of cadmium in “Diamond Knockdown” (0.205mg/l) slightly exceeded the World Health Organization (WHO) permissible limit (0.2mg/kg). Mercury and lead constituted the lowest amount (&lt;0.001mg/l) of heavy metals for both pesticides. Repeated exposure to pesticides often results in bioaccumulation leading to deleterious effect on human health as well as the environment. Therefore, the indiscriminate manufacture and use of pesticides should be strongly discouraged and stiff penalties to offenders should be enforced.

COF-supported zirconium oxyhydroxide as a versatile heterogeneous catalyst for Knoevenagel condensation and nerve agent hydrolysis

A composite of catalytic Lewis acidic zirconium oxyhydroxides (8 wt%) and a covalent organic framework (COF) was synthesized. X-ray diffraction and infrared (IR) spectroscopy reveal that COF's structure is preserved after loading with zirconium oxyhydroxides. Electron microscopy confirms a homogeneous distribution of nano- to sub-micron-sized zirconium clusters in the COF. 3D X-ray tomography captures the micron-sized channels connecting the well-dispersed zirconium clusters on the COF. The crystalline ZrOx(OH)y@COF's nanostructure was model-optimized via simulated annealing methods. Using 0.8 mol% of the catalyst yielded a turnover number of 100-120 and a turnover frequency of 160-360 h-1 for Knoevenagel condensation in aqueous medium. Additionally, 2.2 mol% of catalyst catalyzes the hydrolysis of dimethyl nitrophenyl phosphate, a simulant of nerve agent Soman, with a conversion rate of 37% in 180min. The hydrolytic detoxification of the live agent Soman is also achieved. Our study unveils COF-stabilized ZrOx(OH)y as a new class of zirconium-based Lewis+ Bronsted-acid catalysts.

Designed Metal-Containing Peptoid Membranes as Enzyme Mimetics for Catalytic Organophosphate Degradation.

The detoxification of lethal organophosphate (OP) residues in the environment is crucial to prevent human exposure and protect modern society. Despite serving as excellent catalysts for OP degradation, natural enzymes require costly preparation and readily deactivate upon exposure to environmental conditions. Herein, we designed and prepared a series of phosphotriesterase mimics based on stable, self-assembled peptoid membranes to overcome these limitations of the enzymes and effectively catalyze the hydrolysis of dimethyl p-nitrophenyl phosphate (DMNP)─a nerve agent simulant. By covalently attaching metal-binding ligands to peptoid N-termini, we attained enzyme mimetics in the form of surface-functionalized crystalline nanomembranes. These nanomembranes display a precisely controlled arrangement of coordinated metal ions, which resemble the active sites found in phosphotriesterases to promote DMNP hydrolysis. Moreover, using these highly programmable peptoid nanomembranes allows for tuning the local chemical environment of the coordinated metal ion to achieve enhanced hydrolysis activity. Among the crystalline membranes that are active for DMNP degradation, those assembled from peptoids containing bis-quinoline ligands with an adjacent phenyl side chain showed the highest hydrolytic activity with a 219-fold rate acceleration over the background, demonstrating the important role of the hydrophobic environment in proximity to the active sites. Furthermore, these membranes exhibited remarkable stability and were able to retain their catalytic activity after heating to 60 °C and after multiple uses. This work provides insights into the principal features to construct a new class of biomimetic materials with high catalytic efficiency, cost-effectiveness, and reusability applied in nerve agent detoxification.

Association of urinary organophosphate metabolites with adult asthma patients: a cross-sectional population-based study.

Human health is adversely affected by exposure to organophosphate (OP) pesticides. This study aims to investigate the correlation between urinary OP metabolites and the prevalence of asthma. In cross-sectional studies, data from the National Health and Nutrition Examination Survey (NHANES) projects conducted between 2003-2008, 2011-2012, and 2015-2018 were analyzed. Multiple logistic regressions and restricted cubic spline (RCS) regressions were utilized to examine the relationship between four urinary OP metabolites, namely dimethyl phosphate (DMP), diethyl phosphate (DEP), dimethyl phosphorothioate (DMTP), and diethyl phosphorothioate (DETP), and the prevalence of asthma. Additionally, quantile g-computation (QG-C) regression was employed to evaluate the association between urinary OP metabolites (both individual and combined exposures) and asthma prevalence. The results showed that a total of 9316 adults, including 1298 participants with asthma, were included in the analysis. The median age of the participants was 47.37years, and 50.27% were female. In the comprehensive model, the third tertile of DMP and DEP exhibited a positive association with asthma prevalence compared to the first tertile (odds ratio [95% confidence interval]: 1.26 [1.01-1.57], Ptrend = 0.036; and 1.25 [1.07-1.51], Ptrend = 0.008, respectively). Moreover, a linear relationship was observed between DMP, DEP, and asthma prevalence (P for nonlinearity = 0.320 and 0.553, respectively). The QG-C regression revealed a positive association between the mixture of urinary OP metabolites and asthma prevalence (OR = 1.04 [1.01-1.07], P = 0.025), with DEP contributing the most substantial effect (weight = 0.564). Our findings suggest that exposure to OP pesticides is associated with an increased prevalence of asthma, with DEP demonstrating the strongest impact.

Water in liquid crystal emulsion-based sensing platform for colorimetric detection of organophosphorus pesticide

Development of a simple and convenient method for the rapid detection of organophosphorus pesticides (OPs) is particular important for the safety of environmental water and agriculture products. In this work, the water/liquid crystal (W/LC) emulsion is obtained via dispersing an aqueous solution of sodium dodecyl sulfate (SDS) and peroxidase from horseradish (HRP) into a water-immiscible nematic LC and employed as a sensing platform for the detection of dichlorvos (2, 2-dichlorovinyl dimethyl phosphate, DDVP) that is a typical OP with acute toxicity. Remarkably, the stepwise release of the encapsulated cargo HRP from the W/LC emulsion can be triggered upon the addition of the cationic surfactant myristoylcholine chloride (Myr) due to the strong interfacial charge interactions with the anionic surfactant SDS. The released HRP induces an obvious color change of the overlaying bulk aqueous solution via the H2O2-HRP-TMB reaction system. As Myr can be enzymatically cleaved by AChE, the detection of AChE is fulfilled successfully. This approach is also employed to detect DDVP that can irreversibly inhibit the activity of AChE. This assay shows a linear response between the absorbance of the oxidized TMB solution and the DDVP concentration in the range of 0.001–10 μg/mL (R2 = 0.99). The limit of detection (LOD) and the limit of quantity (LOQ) of DDVP are determined to be 1.9 ng/mL and 6.3 ng/mL, respectively. In addition, this strategy also demonstrates excellent performance for the DDVP detection in real samples, the detection recovery rate of DDVP in water samples (lake water and tap water) and vegetables (tomatoes and cole) by this method is 88.0 % ∼112.6 %, the relative standard deviation (RSD) ≤ 7.5 %. These results suggest the W/LC emulsion-based sensing platform shows great potential for visual detection of DDVP in real samples. In conclusion, the proposed approach is scalable for practical application in food safety as well as environmental monitoring fields, and will provide promising solutions for the assay of pesticide residues.

Solar-thermally enhanced catalytic hydrolysis of chemical warfare agent simulant with UiO-66-NCS decorated reduced graphene oxide aerogels

As chemical warfare agent (CWA) is one of deadly chemicals with strong toxicity and fast action, it is imperative to develop catalytic protective materials that can quickly adsorb and efficiently detoxify CWAs. Herein, reduced graphene oxide (RGO) aerogels are decorated with UiO-66-NCS metal–organic framework with high catalytic activity by in situ growing UiO-66-NH2 inside the RGO hydrogels, converting the UiO-66-NH2 to more active UiO-66-NCS, and freeze-drying for realizing solar-thermally enhanced catalytic hydrolysis of dimethyl 4-nitrophenyl phosphate (DMNP), a chemical warfare agent simulant. Compared with UiO-66-NH2, the UiO-66-NCS is more efficient in catalytically hydrolyzing DMNP with a 30 % accelerated half-life, and the in situ decoration of the RGO aerogel with UiO-66-NCS further improves the catalytic hydrolysis efficiency because of the more exposed active sites of the UiO-66-NCS. Furthermore, the excellent solar-thermal conversion effect of the RGO porous substrate can rapidly generate heat and transfer it to the UiO-66-NCS catalyst, thereby promoting the catalytic activity of the catalyst. The UiO-66-NCS decorated RGO aerogel exhibits a great detoxification efficiency of DMNP under simulated solar light irradiation with a turnover frequency of as high as 0.0531 s−1, ∼2.3 times higher than that under room light, and 1.5 times better than that of UiO-66-NCS powder. The solar-thermally enhanced catalytic hydrolysis of DMNP with the UiO-66-NCS decorated RGO aerogel is demonstrated by the quick detoxification of CWA simulant with great recyclability.

Association of Prenatal Exposure to Organophosphate, Pyrethroid, and Neonicotinoid Insecticides with Child Neurodevelopment at 2 Years of Age: A Prospective Cohort Study.

Widespread insecticide exposure might be a risk factor for neurodevelopment of our children, but few studies examined the mixture effect of maternal coexposure to organophosphate insecticides (OPPs), pyrethroids (PYRs), and neonicotinoid insecticides (NNIs) during pregnancy on child neurodevelopment, and critical windows of exposure are unknown. We aimed to evaluate the association of prenatal exposure to multiple insecticides with children's neurodevelopment and to identify critical windows of the exposure. Pregnant women were recruited into a prospective birth cohort study in Wuhan, China, from 2014-2017. Eight metabolites of OPPs (mOPPs), three metabolites of PYRs (mPYRs), and nine metabolites of NNIs (mNNIs) were measured in 3,123 urine samples collected at their first, second, and third trimesters. Children's neurodevelopment [mental development index (MDI) and psychomotor development index (PDI)] was assessed using the Bayley Scales of Infant Development at 2 years of age (). Multivariate linear regression models, generalized estimating equation models, and weighted quantile sum (WQS) regression were used to estimate the association between the insecticide metabolites and Bayley scores. Potential sex-specific associations were also examined. Single chemical analysis suggested higher urinary concentrations of some insecticide metabolites at the first trimester were significantly associated with lower MDI and PDI scores, and the associations were more prominent among boys. Each 1-unit increase in ln-transformed urinary concentrations of two mOPPs, 3,5,6-trichloro-2-pyridinol and 4-nitrophenol, was associated with a decrease of 3.16 points [95% confidence interval (CI): , ] and 3.06 points (95% CI: , ) respectively in boys' MDI scores. Each 1-unit increase in that of trans-3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylic acid (trans-DCCA; an mPYR) was significantly associated with a decrease of 2.24 points (95% CI: , ) in boys' MDI scores and 1.90 points (95% CI: , ) in boys' PDI scores, respectively. Significantly positive associations of maternal urinary biomarker concentrations [e.g., dimethyl phosphate (a nonspecific mOPP) and desmethyl-clothianidin (a relatively specific mNNI)] with child neurodevelopment were also observed. Using repeated holdout validation, a 1-quartile increase in the WQS index of the insecticide mixture (in the negative direction) at the first trimester was significantly associated with a decrease of 3.02 points (95% CI: , ) in MDI scores among the boys, and trans-DCCA contributed the most to the association (18%). Prenatal exposure to higher levels of certain insecticides and their mixture were associated with lower Bayley scores in children, particularly in boys. Early pregnancy may be a sensitive window for such an effect. Future studies are needed to confirm our findings. https://doi.org/10.1289/EHP12097.

Catalytic degradability and anti-permeability of peelable coating based on organophosphate nerve agent simulants

The contamination of equipment surfaces with organophosphate nerve agents (NAs) has posed a great threat to the safety of military personnel due to their latent contact risk. Herein, a functional filler GO@UiO-66-NH2 was designed by facile in-situ synthesis of UiO-66-NH2 nanoparticles on graphene oxide (GO) surfaces, which not only maintained the catalytic activity of nanoparticles, but also significantly improved the compatibility of GO carrier with the polyvinyl butyral (PVB) peelable coating. By further optimizing the amount of GO@UiO-66-NH2 added into PVB coating, it was found that a desirable 97.6% hydrolysis conversion of dimethyl p-nitrophenyl phosphate (DMNP, a typical reactivity simulant of NAs) could be realized within 48 h. Moreover, the intrinsic flaky structure of GO@UiO-66-NH2 also endowed the composite coating with effective physical anti-permeability to the aqueous solutions of dimethyl methyl phosphate (DMMP, a representative structure simulant of NAs), especially when the DMMP concentrations were below 50 wt%, no permeated DMMP molecules was detected even after 48 h. In addition, the existence of GO@UiO-66-NH2 further enhanced the mechanical stability of composite coating in both flexibility and peelability, facilitating its convenient removal from substrate surfaces after service. It is expected that this work can provide a feasible strategy for the effective protection of equipment surfaces exposed to NAs.

Risk Assessment of Residual Pesticides of Phaseolus vulgaris L. Consumed in Port Harcourt, Rivers State, Nigeria

Pesticides are important and necessary in reducing the loss caused by insect infestation on grains. However, its toxicity and persistence in the environment is of health concern. Beans (Phaseolus vulgaris L.) preserved with insecticide are considered to be good for consumption if its content of insecticide is not higher than the maximum residue limits (MRLs). The aim of this research was to quantify the residue of pesticide in four beans samples and determine the health risk associated with consuming these foods by residents of Port Harcourt, Rivers State, Nigeria. Pesticides content of beans samples were analyzed using Gas Chromatography (GC). The results of the study showed the presence of 17 different pesticide residues in all samples of beans. 2,4-Dichlorophenoxyacetic acid (2,4-D) and 2,2-dichlorovinyl dimethyl phosphate (DDVP) were detected in all samples of beans and at levels above European Union’s (EU's) MRL except in iron beans samples. Glyphosate was detected in all the samples at concentration above EU’s MRL. However, pesticides in Raw iron beans such as carbofuran (0.43±0.03 mg/kg), Endosulphan (0.18±0.01 mg/kg), HCB (0.62±0.10 mg/kg) Profenos (0.55±0.04 mg/kg) and t-nonachlor (0.32±0.00 mg/kg) decreased significantly to 0.23±0.10 mg/kg, 0.09±0.01 mg/kg, 0.31±0.01 mg/kg, 0.38±0.01 mg/kg, and 0.22±0.00 mg/kg respectively in Parboiled iron beans. This indicates reduced Health Risk Index (HRI) to pesticides of parboiled beans samples. Similar results were also recorded in other raw and parboiled beans varieties studied. This calls for the attention of regulatory agencies in foods and food products to effectively monitor the use and application of pesticides on foodstuff and also encourage parboiling before cooking to eat.

Construction of imidazole@defective hierarchical porous UiO-66 and fibrous composites for rapid and nonbuffered catalytic hydrolysis of organophosphorus nerve agents

Hydrolytic destruction of toxic organophosphorus nerve agents by metal-organic framework (MOF) catalysts is commonly reliant on bulk water and volatile liquid base, preventing real-world implementation. Poor accessibility to MOF-based active sites in heterogeneous catalysis is also a crucial factor since reactants diffusion is limited by inherently small micropores. To overcome these practical limitations, a ligand-selective pyrolysis strategy was used to construct unsaturated Zr defects and additional mesopores in UiO-66(Zr). Owing to synergistic effect of Zr defects and hierarchical pores, hydrolysis rate constant (k) of nerve agent simulant DMNP (dimethyl 4-nitrophenyl phosphate) on optimal DHP-UiO-30% (defective hierarchical porous UiO-66) is 3.2 times higher than counterpart UiO-30% in N-ethylmorpholine buffer. Encapsulating imidazole (Im) into DHP-UiO-30% affords Im@DHP-UiO, mimicking phosphotriesterase. Im-72@DHP-UiO exhibits rapid DMNP detoxification with 99% conversion in 12 min and initial half-life (t1/2) of 1.8 min in nonbuffered water. As the first example of ‘three-in-one’ detoxifier, Im@DHP-UiO is further integrated onto nonwoven fabric to construct Im@DHP/Fiber, achieving solid-phase detoxification at ambient humidity with t1/2 of 19.6 min and final conversion of 91%. This is comparable to many powdered catalysts in aqueous solution buffered by volatile bases. This unified strategy is critical and viable to efficiently hydrolyze nerve agents in practical settings.

The Association Between Urinary Concentrations of Organophosphate Metabolites and Asthma-Related Outcomes Among Schoolchildren From Informal Settlements.

Objectives: There is inconsistent evidence on the relationship between pesticide exposure and childhood respiratory outcomes in non-agricultural settings. This study investigated the association between organophosphate (OP) pesticide exposure and asthma-related outcomes in children residing in four informal settlements. Methods: The study was a longitudinal study of 590 schoolchildren, with a 12months follow-up period. A standardised questionnaire adopted from the International Study of Asthma and Allergies in Childhood was administered to caregivers for child's respiratory symptoms and household characteristics. Spirometry and fractional-exhaled nitric oxide, including a phadiatop test (atopy status) and urinary dialkyl phosphate (DAP) metabolites were measured at baseline and follow-up. DAP metabolites included diethylphosphate (DEP) and dimethyl phosphate (DMP) measured at baseline and follow-up and dimethylthiophosphate (DMTP) measured only at baseline. Results: The mean ages of schoolchildren were 9.9 ± 0.91years and the overal incidence proportions of new doctor diagnosed asthma was 2.2%. No consistent patterns of increased risk of asthma outcomes with increasing DAP concentrations was found in multivariate analysis. Conclusion: Future studies with longer follow-up periods and repeated OP biomonitoring are recommended.