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Marajó Island, an environmental protection area for sustainable use in the Brazilian Amazon, was the first region in Brazil to apply the pesticide DDT, a persistent organic pollutant (POP), to control malaria outbreaks. This study investigated background levels of various POPs, including o,p'- and p,p'-DDT and their primary metabolites (o,p'- and p,p'-DDE, o,p'- and p,p'-DDD), as well as hexachlorocyclohexane (α-, β-, γ-, δ-HCH), using estuarine surface sediments and sediment cores from areas influenced by urbanization and agriculture. All samples were collected during the dry season (September 2014). Surface sediments exhibited ΣDDT concentrations up to 2.71 ng g⁻1, with isomeric ratios indicating past DDT application and contributions from dicofol. Sediment profiles revealed alternating aerobic and anaerobic degradation processes of DDT. Other organochlorinated contaminants were not detected. The presence of γ-HCH as the main isomer (0.24 to 0.90 ng g⁻1) in surface samples suggests recent lindane application as a wood preservative or cattle parasite treatment. A dated sediment core revealed historical contamination of early DDT tests in the Amazon during the mid-1940s. Increasing ΣDDT concentrations (up to 12.3 ng g⁻1) were identified in the 1970s, coinciding with the intensification of DDT use for public health campaigns, which lasted until 2009 and reached the highest ΣDDT flux. Legal restrictions on the use and commercialization of POPs, along with natural degrading processes, likely led to decreased accumulation and limited ecological risks. Furthermore, the low concentrations of POPs suggested biodegradation and dispersion from northeast to southeast. [ABSTRACT FROM AUTHOR]

In accordance with Article 43 of Regulation (EC) 396/2005, EFSA received a request from the European Commission to review the existing maximum residue levels (MRLs) for the non‐approved active substance dicofol in view of the possible lowering of the MRL. EFSA investigated the origin of the current EU MRLs. All existing EU MRLs reflect previously authorised uses in the EU or are based on obsolete Codex Maximum Residue Limits. Furthermore, in view of the limitations of the toxicological dataset and related uncertainties, the existing toxicological reference values derived at the EU level cannot be confirmed for dicofol. EFSA therefore proposed lowering all existing EU MRLs for dicofol to the limit of quantification. [ABSTRACT FROM AUTHOR]

Dicofol is a highly toxic residual pesticide in tea, which seriously endangers human health. A method for detecting dicofol in tea by combining stoichiometry with surface-enhanced Raman spectroscopy (SERS) technology was proposed in this study. AuNPs were prepared, and silver shells were grown on the surface of AuNPs to obtain core–shell Au@AgNPs. Then, the core–shell Au@AgNPs were attached to the surface of a PDMS membrane by physical deposition to obtain a Au@AgNPs/PDMS substrate. The limit of detection (LOD) of this substrate for 4-ATP is as low as 0.28 × 10−11 mol/L, and the LOD of dicofol in tea is 0.32 ng/kg, showing high sensitivity. By comparing the modeling effects of preprocessing and variable selection algorithms, it is concluded that the modeling effect of Savitzky–Golay combined with competitive adaptive reweighted sampling–partial least squares regression is the best (Rp = 0.9964, RPD = 10.6145). SERS technology combined with stoichiometry is expected to rapidly detect dicofol in tea without labels. [ABSTRACT FROM AUTHOR]

Although dicofol has been widely banned all over the world as a kind of organochlorine contaminant, it still exists in the environment. This study developed a high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS/MS) detection technique for dicofol, an environmental pollutant, for the first time using in-source fragmentation. The results confirmed that m/z 251 was the only precursor ion of dicofol after in-source fragmentation, and m/z 139 and m/z 111 were reasonable product ions. The main factors triggering the in-source fragmentation were the H+ content and solution conductivity when dicofol entered the mass spectrometer. Density functional theory can be used to analyze and interpret the mechanism of dicofol fragmentation reaction in ESI source. Dicofol reduced the molecular energy from 8.8 ± 0.05 kcal/mol to 1.0 ± 0.05 kcal/mol, indicating that the internal energy release from high to low was the key driving force of in-source fragmentation. A method based on HPLC-MS/MS was developed to analyze dicofol residues in environmental water. The LOQ was 0.1 μg/L, which was better than the previous GC or GC-MS methods. This study not only proposed an HPLC-MS/MS analysis method for dicofol for the first time but also explained the in-source fragmentation mechanism of compounds in ESI source, which has positive significance for the study of compounds with unconventional mass spectrometry behavior in the field of organic pollutant analysis and metabonomics. [ABSTRACT FROM AUTHOR]

Tetranychus gloveri, a recently introduced mite species in Kerala, India has now established in the state as a predominant mite pest on ornamental plants. In this study, the status of acaricide resistance and the activity of detoxification enzymes were investigated in the populations of T. gloveri collected on Adenium plants from six different commercial horticultural nurseries of Thrissur district, Kerala, India. Adulticidal bioassays were performed for fenazaquin and dicofol, while nymphicidal bioassays were conducted for spiromesifen to estimate the LC50. The field populations showed resistance ratios in the range of 1.66–14.38-fold for fenazaquin, 1.06–27.31-fold for spiromesifen and 1.22–3.65-fold for dicofol, compared to the laboratory-maintained reference population. Enzyme assays of detoxifying enzymes revealed enhanced activity of carboxylesterase by 1.03–3.52-fold and cytochrome P450 monooxygenase by 1.01–2.08-fold in the field populations. However, the role of glutathione S-transferase in the development of resistance in different field populations was insignificant. The study recorded the development of resistance in the spider mite, T. gloveri to new generation acaricides spiromesifen and fenazaquin for the first time and also confirmed the significant role of the carboxylesterases and cytochrome P450 monooxygenases in imparting resistance in T. gloveri. [ABSTRACT FROM AUTHOR]

The residues of pesticides that reach water resources from agricultural activities in several ways contaminate drinking water resources and threaten aquatic life. This study aimed to investigate the performance of three reverse osmosis (RO) membranes (BW30-LE, SW30-XLE, and GE-AD) in rejecting four different pesticides (tributyl phosphate, flutriafol, dicofol, and irgarol) from secondary treated urban wastewater and also to elucidate the mechanisms underlying the rejection of these pesticides. RO experiments were conducted using pesticide-spiked wastewater samples under 10 and 20 bar transmembrane pressures (TMP) and membrane performances were evaluated. Overall, all the membranes tested exhibited over 95% rejection performances for all pesticides at both TMPs. The highest rejections for tributyl phosphate (99.0%) and irgarol (98.3%) were obtained with the BW30-LE membrane, while for flutriafol (99.9%) and dicofol (99.1%) with the GE-AD membrane. The increase in TMP from 10 to 20 bar did not significantly affect the rejections of all pesticides. The rejection performances of RO membranes were found to be governed by projection area as well as molecular weight and hydrophobicity/hydrophilicity of pesticides. Among the membranes tested, the SW30-XLE membrane was the most prone to fouling due to the higher roughness. [ABSTRACT FROM AUTHOR]

In this work, the preparation and characterization of an iridium coated titanium anode (Ti/IrO2) and a ruthenium coated titanium anode (Ti/RuO2) for dicofol (DZ) degradation is examined using the electrochemical oxidation process (EO). X-ray diffraction (XRD) and scanning electron microscope (SEM) are used to characterize the metal oxide-coated anodes. The operating parameters in EO, including current density, electrolyte (NaCl) dose, pH, and electrolysis time for the degradation of dicofol, are studied in detail. Box-Behnken response surface design (BBD) incorporated in response surface methodology (RSM) is used to optimize and model the dicofol degradation process. The dicofol degradation and electrical energy consumption are taken as responses. Numerical optimization is used to determine the optimal conditions (current density of 0.1 A/m2, electrolyte dose of 3.5 mM, pH of 7, and electrolysis time of 8 min). Ninety-three percent of dicofol is degraded with an electrical energy consumption value of 0.75 KWh/m3 using Ti/IrO2 anode under optimal conditions.

The objective of this research was to investigate dicofol removal by laccase from Lentinus polychrous Lev. in a membrane bioreactor with addition of natural organic matter (NOM) and heavy metals solutions (iron and manganese) at concentration 0-50 mg/l, dicofol concentration 1 mg/l, laccase concentration 4.32 U/ml, pH 7 and temperature at 28±3 ºC. Based on the results of the dicofol removal efficiency in the membrane bioreactor system at 240 minutes, it was found that increasing the concentration of natural organic matter and iron solution caused a decrease in removal efficiency. At maximum NOM or iron concentrations of 50 mg/l the dicofol removal efficiency was only 72 and 83%, respectively. Increasing the concentration of manganese, increased the efficiency of dicofol removal. The efficiency of dicofol removal was 100% at all manganese concentration and the efficiency of dicofol removal in the membrane bioreactor was not less than 80% at 480 minutes in all conditions. This study indicates a good potential for application of laccase for dicofol removal in a membrane bioreactor.

This research aims to apply gaseous ozone to degrade pesticides (cypermethrin and dicofol) residues in dried basil leaves and to investigate their qualities after fumigation. Sweet basil, holy basil, hairy basil, and tree basil were fumigated with 200 mg/L gaseous ozone. The result showed that half-life of cypermethrin and dicofol in dried basil under ozone fumigation were in the range of 13.1–31.6 and 9.4–18.9 min, respectively. Ozone fumigation exhibited at least 99.9% reduction of pesticide residue in comparison with self-degradation. In addition, this process does not significantly affect phenolic compounds and antioxidants in dried basil at 95% confidence level. [ABSTRACT FROM AUTHOR]

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Dicofol is an organochlorine insecticide widely used to prevent pests worldwide. Consequently, serious environmental problems have arisen from the application of dicofol. Bioremediation is an effective solution for dicofol persistence in the environment. In this study, a bacterial strain D-2, identified to genus Microbacterium, capable of degrading dicofol was isolated from dicofol-contaminated agricultural soil. This represents the first dicofol degrading bacterium isolated from this genus. Microbacterium sp. D-2 degraded 50 mg/L dicofol within 24 h at a rate of 85.1%. Dicofol was dechlorinated by D-2 and the further degradation metabolite was indentified as p,p′-dichlorobenzophenone(DCBP). Soils inoculated with Microbacterium sp. D-2 degraded 81.9% of the dicofol, while soils without D-2 only degraded 20.5% of the dicofol present. This finding suggests that strain D-2 has great potential in bioremediation of dicofol-contaminated soils. [ABSTRACT FROM AUTHOR]

The objective of this research was to investigate dicofol removal by laccase from Lentinus polychrous Lev. in a membrane bioreactor with addition of natural organic matter (NOM) and heavy metals solutions (iron and manganese) at concentration 0-50 mg/l, dicofol concentration 1 mg/l, laccase concentration 4.32 U/ml, pH 7 and temperature at 28±3 ºC. Based on the results of the dicofol removal efficiency in the membrane bioreactor system at 240 minutes, it was found that increasing the concentration of natural organic matter and iron solution caused a decrease in removal efficiency. At maximum NOM or iron concentrations of 50 mg/l the dicofol removal efficiency was only 72 and 83%, respectively. Increasing the concentration of manganese, increased the efficiency of dicofol removal. The efficiency of dicofol removal was 100% at all manganese concentration and the efficiency of dicofol removal in the membrane bioreactor was not less than 80% at 480 minutes in all conditions. This study indicates a good potential for application of laccase for dicofol removal in a membrane bioreactor. [ABSTRACT FROM AUTHOR]

An electrochemical sensor was fabricated by construction of nickel nanowires on the surface of poly(p‐aminophenol) (PPAP) modified glassy carbon electrode. The electrochemical response of dicofol, a known pesticide and used for agricultural activities such as cyclic voltammetry and differential pulse voltammetry, were investigated and the results were compared with those obtained unmodified electrodes. Following the optimization of NaOH concentration, polymerization cycle number, Ni nanowire amount, the linear range for the dicofol was studied and found as 0.83–30.7 μmol L−1 (R2=0.9981) at Ni/PPAP/GCE with a 0.08 μmol L−1 detection limit according to S/N=3. Finally, the proposed Ni/PPAP/GCE sensor was successfully applied for the dicofol analysis in soil samples. The characterization of the developed surface was carried out by scanning electron microscopy and X‐Ray photoelectron spectroscopy. [ABSTRACT FROM AUTHOR]

Abstract The Pearl River Delta (PRD) is one of the areas with higher environmental concentration of organochlorine pesticides (OCPs), being DDT one of the most abundant. In this work, 4,4′-dichlorobenzophenone (4,4′-DCBP), a common metabolite of dicofol (DDT related) and DDT, was quantified in surface waters of Hong Kong and Macao, together with the analysis of physicochemical and nutrients parameters. Hong Kong presented higher 4,4′-DCBP mean levels (12.50 ng/L) than Macao (4.05 ng/L), which may be due to the use of dicofol as a pesticide and DDT as antifouling-paint for ships. The region presented a possible eutrophication state due to the high nutrients' concentration. For the first time, toxicity evaluation of this metabolite in Artemia salina and Daphnia magna was done, in order to compute valid EC 50 s and theoretically evaluate the risk in the PRD. The toxicity results (EC 50 = 0.27 mg/L for A. salina; and EC 50 = 0.17 mg/L and LC 50 = 0.26 mg/L for D. magna), together with the 4,4′-DCBP levels quantified, indicated a low environmental risk. Graphical abstract fx1 Highlights • Average 4,4′-DCBP concentrations (ng/L) detected in Hong Kong were 3-folds higher than in Macao. • Hong Kong and Macao areas presented possible eutrophication state due to high nutrients concentration. • Risk assessment results showed a low environmental risk (RQ < 0.1) for the levels detected. [ABSTRACT FROM AUTHOR]

ISJ 13: 350-354, 2016 ISSN 1824-307X Red spider mites (RSM) is one of the major pest of tea and reported from all tea producing regions around the world. Chemical acaricides are the primary control method against this pest which induced biochemical changes in the RSM. In this study early expression of heat shock proteins have been observed in RSM exposed to commonly used acaricides viz., ethion, dicofol and fenpropathrin. In case of pesticide exposed RSM, hsp90 showed more prominent bands than the hsp70 in immunoblotted membrane, indicating that the intensity of expression of hsp90 in RSM against pesticides is higher than hsp70. Hsp70 expression is higher in ethion and fenpropathrin induced RSM than that of dicofol. Ethion and fenpropathrin treated RSM were not showing any difference when compared based on exposure time, whereas dicofol treated once showed more expression in short time. The expression of hsp90 is significantly higher in the dicofol treated samples followed by fenpropathrin, however ethion treated sample showed marginally higher hsp90 expression than control.

Large quantities of organochlorine pesticides (OCPs) have been used in tropical regions. The fate processes and risks of these legacy contaminants in the tropics are poorly understood. Herein, we investigated the occurrence of three classes of widely used OCPs and their metabolites in surface and core soil from five cities across Vietnam with a prevalent tropical monsoon climate and a long history of OCP application. We aimed to elucidate migration potentials, degradation conditions, and transformation pathways and assess current health risks of these contaminants. Generally, the concentrations of OCPs and metabolites in the soil core were slightly lower than those in surface soil except for hexachlorocyclohexane (HCH) isomers. 2,2-bis(4-chlorophenyl)-1,1,1-trichloroethane (p,p'-DDT), 2,2-bis(4-chlorophenyl)-1,1-dichloroethylene (p,p'-DDE), the sum of dicofol and 4,4'-dichlorobenzophenone (p,p'-DBP), and 2,2-bis(4-chlorophenyl)-1,1-dichloroethane (p,p'-DDD) were the most abundant compounds in both surface and core soils. A uniform distribution of HCHs (the sum of α-, β-, γ-, and δ-HCH) at trace levels was found in almost all soils, serving as evidence of the lack of recent use of HCH pesticides. Higher concentrations of DDTs (the sum of DDT, DDD, and DDE) were observed in north-central Vietnamese soil, whereas appreciable concentrations of ENDs (the sum of α- and β-endosulfan and endosulfan sulfate) were only found in southern Vietnamese soils. Empirical diagnostic ratios indicated residuals of DDTs were mainly from technical DDT rather than dicofol, whereas aged HCHs could be explained by the mixture of lindane and technical HCH. Both historical applications and recent input explain DDTs and ENDs in Vietnamese soil. Total organic carbon performs well in preventing vertical migration of more hydrophobic DDTs and ENDs. The dominant transformation pathway of DDT in surface soil followed p,p'-DDE→2,2-bis(4-chlorophenyl)-1-chloroethylene or p,p'-DDMU→1,1-bis(4-chlorophenyl)ethylene or p,p'-DDNU→p,p'-DBP, whereas the amount of p,p'-DDMU converted from p,p'-DDD and p,p'-DDE is similar in soil core. Non-cancer risks of OCPs and metabolites in all soils and cancer risks of those chemicals in core soils were below the safety threshold, whereas a small proportion of surface soil exhibited potential cancer risk after considering the exposure pathway of vegetable intake. This study implied that organic matter in non-rainforest tropical deep soils still could hinder the leaching of hydrophobic organic contaminants as in subtropical and temperate soils. When lands with a history of OCP application are used for agricultural purposes, dietary-related risks need to be carefully assessed., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Horse gram, Macrotyloma uniflorum L. a highly protienous pulse crop of greater importance, is widely grown in India. Horse gram is cultivated throughout the year both under irrigated and rainfed conditions. It is obvious that the quality and quantity of the horse gram was drastically reduced by various insect and non-insect pests. Among these pests, two spotted spider mite, Tetranychus utricae (Koch) also cause heavy damage to the horse gram crop. Study was carried out to evaluate the efficacy of various native botanical extracts and two acaricides against two spotted spider mite on horse gram. Treatments includes the Andrographis leaf extract, Pongamia leaf extract, Eucalyptus leaf extract, Vitex leaf extract, Lawsonia leaf extract, Dicofol and Proporgite, an untreated check were tested for its efficacy against mite. The mite mortality was recorded as maximum in case of dicofol and proporgite followed by the Acalypha and Vitex leaf extracts. As maximum mite mortality was recorded in case of Proporgite (81.06%) and Dicofol (79.58%) followed by Andrographis leaf extract (63.27%). Vitex leaf extract (60.72%) and Pongamia leaf extract (60.58%) recorded on par efficacy against mite. Eucalyptus leaf extract shows moderate efficacy against mite. The least was recorded in case of the Lawsonia leaf extract (48.31%) against two spotted spider mite after 48 hours of release. [ABSTRACT FROM AUTHOR]

Abstract As an effective organochlorine pesticide, Dicofol has been extensively applied in more than 30 countries for protecting over 60 different crops. Considering its large consumption and potential adverse effect on human health (endocrine disrupting and carcinogenicity), the fate of Dicofol sprayed into the air is of public concern. In this study, we conducted a comprehensive study on the reaction mechanisms of p,p' -Dicofol with OH and NO 3 radicals using DFT method. Comparing the abstrations by OH and NO 3 radical, OH and NO 3 radical addition reactions are predominant due to the lower potential barriers and stronger heat release. The phenolic substances (P1 P5), epoxides (P11 and P15), dialdehyde (P13) and other species (P8, P9, P10 and P14) are generated by OH additions and their subsequent reactions while OH abstraction reactions produce DCBP, P7 and chlorphenyl radical. Particularly, NO 3 additions and their subsequent reactions yield dialdehydes (P16 and P17) and 2,8-DCDD, which is the first report of the generation of dioxin from atmospheric oxidation of p,p' -Dicofol. Additionally, based on the structure optimization and energy calculation, rate constants and Arrhenius formulas of the elementary reactions of p,p' -Dicofol with OH and NO 3 radicals were obtained over the temperature range of 280–380 K and at 1 atm. The rate constants for the reactions of p,p' -Dicofol with OH and NO 3 radicals are 1.51 × 10−12 and 8.88 × 10−14 cm3 molecule−1 s−1, respectively. The lifetime (τ Total) of p,p' -Dicofol determined by the reactions of OH and NO 3 radical is 5.86 h, indicating a potential long-range transport in the atmosphere. Graphical abstract Image 1 Highlights • We studied a comprehensive mechanism of the reactions between p,p' -Dicofol and OH/NO 3 radicals. • The lifetime (τ Total) of p,p' -Dicofol determined by the reactions with OH and NO 3 radical is 5.86 h. • NO 3 addition and its subsequent reactions yield 2,8-DCDD. [ABSTRACT FROM AUTHOR]

Highlights • Hydrodynamic cavitation is effective for the removal of Dicofol. • Highest rate of Dicofol degradation was observed at an inlet pressure of 7 bar. • HPLC and GC–MS analysis illustrated the presence of transformed products of Dicofol. • TOC removal of 85% was obtained within 60 min of treatment. Abstract Dicofol, a recommended Stockholm convention persistent organic pollutants (POPs) candidate is well known for its endocrine disruptive properties and has been extensively used as an organochlorine pesticide worldwide. The hydrodynamic cavitation (HC) treatment of Dicofol in aqueous media induced by a liquid whistle hydrodynamic cavitaion reactor (LWHCR) has been investigated while considering important parameters such as inlet pressure, initial concentration of Dicofol, solution temperature, pH, addition of H 2 O 2 and radical scavenger for the extent of degradation. The pseudo-first-order degradation rate constant (k) was determined to be 0.073 min−1 with a cavitational yield of 1.26 × 10−5 mg/J at optimum operating conditions and a complete removal of Dicofol was achieved within 1 h of treatment. Considering the removal rate and energy efficiency, the optimal inlet pressure was found to be 7 bar, resulting in a cavitation number of 0.17. High performance liquid chromatography (HPLC) and Gas chromatography mass spectroscopy (GC–MS) analyses indicated a sharp decline in the concentration of Dicofol with treatment time and indicated the presence of degraded products. An 85% total organic carbon (TOC) removal was achieved within 1 h of treatment time, demonstrating successful mineralization of Dicofol. The obtained results suggest that the degradation of Dicofol followed thermal decomposition and successive recombination reactions at bubble-vapor interface. Overall, the attempted hydrodynamic cavitation demonstrated successful and rapid removal of endocrine disruptive chemicals such as Dicofol and is expected to provide efficient solution for wastewater treatment. [ABSTRACT FROM AUTHOR]

Abstract A special initiative in the Global Atmospheric Passive Sampling (GAPS) Network was implemented to provide information on new and emerging persistent organic pollutants (POPs) in the Group of Latin America and Caribbean (GRULAC) region. Regional-scale atmospheric concentrations of the new and emerging POPs hexachlorobutadiene (HCBD), pentachloroanisole (PCA) and dicofol indicators (breakdown products) are reported for the first time. HCBD was detected in similar concentrations at all location types (<20–120 pg/m3). PCA had elevated concentrations at the urban site Concepción (Chile) of 49–222 pg/m3, with concentrations ranging <1–8.5 pg/m3 at the other sites in this study. Dicofol indicators were detected at the agricultural site of Sonora (Mexico) at concentrations ranging 30–117 pg/m3. Legacy POPs, including a range of organochlorine (OC) pesticides and polychlorinated biphenyls (PCBs), were also monitored to compare regional atmospheric concentrations over a decade of monitoring under the GAPS Network. γ-hexachlorocyclohexane (HCH) and the endosulfans significantly decreased (p < 0.05) from 2005 to 2015, suggesting regional levels are decreasing. However, there were no significant changes for the other legacy POPs monitored, likely a reflection of the persistency and slow decline of environmental levels of these POPs. For the more volatile OCs, atmospheric concentrations derived from polyurethane foam (PUF) (acting as an equilibrium sampler) and sorbent impregnated PUF (SIP) (acting as a linear phase sampler), were compared. The complimentary methods show a good agreement of within a factor of 2–3, and areas for future studies to improve this agreement are further discussed. Graphical abstract Image 1 Highlights • First reporting of hexachlorobutadiene and dicofol from the GRULAC region. • First regional scale data of pentachloroanisole from the GRULAC region. • PUF and SIP disk derived atmospheric concentrations agree within factor of 3. • γ-hexachlorohexane and the endosulfans significantly decreased from 2005 to 2015. • Other legacy POPs did not see decreasing concentrations from 2005 to 2015. Regional scale atmospheric concentrations of hexachlorobutadiene, pentachloroanisole and dicofol are reported for the first time in the GRULAC region, along with concentrations of legacy POPs with only γ-hexachlorocyclohexane and endosulfans significantly reducing (p < 0.05) in the region from 2005 to 2015. A comparison study of SIP-PAS vs PUF-PAS demonstrated the applicability of both media for monitoring more volatile POPs. [ABSTRACT FROM AUTHOR]

Dicofol, an extensively used organochlorine pesticide and a recommended Stockholm convention persistent organic pollutant (POP) candidate is well known for its endocrine disruptive properties. The sonochemical degradation of Dicofol in aqueous media has been investigated using a 20-kHz probe type sonicator with power inputs from 150 to 450 W. The degradation rate was determined as a function of concentration of Dicofol, solution pH, bulk phase temperature, ultrasonic power density and H 2 O 2 addition. At optimum operating conditions, the pseudo-first-order degradation rate constant (k) was determined to be 0.032 min −1 and the extent of degradation was found to be 86% within 60 min of ultrasound treatment. High performance liquid chromatography (HPLC) and Gas chromatography coupled with mass spectroscopy (GC-MS) analysis indicated the presence of degraded products. The obtained results of Dicofol degradation and control experiments in the presence of H 2 O 2 and radical scavenger test suggest thermal decomposition along with radical attack at bubble-vapor interface to be the dominant degradation pathway. Sonochemical treatment is effective and promising for successful removal of harmful pesticides such as Dicofol and superior removal efficiency for other POPs is expected in the near future with the successful implementation of ultrasound-based wastewater treatment. [ABSTRACT FROM AUTHOR]

Dicofol (2,2,2-trichloro-1,1-bis-( p -chlorophenyl)ethanol) found in the environment is not only a miticide originated from commercial use, but also a metabolite of dichlorodiphenyltrichloroethane (DDT), which is often overlooked. To verify the sources and transformation pathways of DDT and related metabolites in soils, we measured p,p’ -(dicofol + DBP) (sum of p,p’ -dicofol and 4,4′-dichlorobenzophenone), DDT and six metabolites in soils from Northwest Fujian, China. The ratios of 1,1,1-trichloro-2-( o -chlorophenyl)-2-( p -chlorophenyl)ethane ( o,p’ -DDT)/1,1,1-trichloro-2,2-bis-( p -chlorophenyl)ethane ( p,p’ -DDT) and the mass balance demonstrated that p,p’ -(dicofol + DBP) predominantly originated from p,p’ -DDT transformation rather than from actual dicofol application. p,p’ -(dicofol + DBP) accounted for 45.0% as the primary metabolites of DDT in this study, more than 1,1-dichloro-2,2-bis-( p -chlorophenyl)ethylene ( p,p’ -DDE) and 1,1-dichloro-2,2-bis-( p -chlorophenyl)ethane ( p,p’ -DDD), which might lead to large overestimations of the fresh DDT input by using the traditional ratio of (∑ 2 DDD + ∑ 2 DDE)/∑ 2 DDT (with all o,p’ - and p,p’ - isomers included). In paddy fields where the conditions alternate between aerobic (dry period) and anaerobic (wet period), both p,p’ -DDD and p,p’ -DDE were likely to degrade to 1-chloro-2,2-bis-( p -chlorophenyl)ethylene ( p,p’ -DDMU), which further transformed to 2,2-bis( p -chlorophenyl)ethylene ( p,p’ -DDNU). Degradation of p,p’ -DDMU to p,p’ -DDNU mainly occurred in waterlogged paddy soils. However, p,p’ -DDNU might not transform to other higher-order metabolites in aerobic surface soils. Overall, our study confirmed p,p’ -(dicofol + DBP) as metabolites of p,p’ -DDT, suggested DDE and DDD were parallel precursors of DDMU, and further verified the transformation pathways of DDT in surface soils. [ABSTRACT FROM AUTHOR]

Environmental exposure to dicofol (DCF), one of common organochlorine pesticides (OCPs) widely used for controlling agricultural pests, elicits a potential risk for human health due to its toxicity. However, potential physiological hazards of oral DCF exposure remain largely unknown. Mice were exposed to relatively chronic and subacute DCF at different doses (5, 20 and 100 mg/kg) by gavage for 2 weeks. 1H NMR-based metabolomics was used to explore alterations of metabolic profiling induced by DCF exposure. Targeted metabolomics was subsequently employed to investigate the dose-dependent effects of oral DCF exposure on lipid metabolism and the gut microbiota-derived metabolites of mice. 16S rRNA gene sequencing was further employed to evaluate the changes of gut community of mice exposed to DCF. Oral exposure to DCF dose-dependently induced liver injury, manifested by hepatic lipogenesis, inflammation and liver dysfunction of mice. Typically, DCF exposure disrupted host fatty acids metabolism that were confirmed by marked alteration in the levels of related genes. DCF exposure also dose-dependently caused dysbiosis of the gut bacteria and its metabolites including altered microbial composition accompanied by inhibition of bacterial fermentation. These results provide metabolic evidence that DCF exposure dose-dependently induces liver lipidosis and disruption of the gut microbiota in mice, which enrich our views of molecular mechanism of DCF hepatoxicity. [Display omitted] • DCF dose-dependently induced hepatic lipogenesis, inflammation and liver dysfunction of mice. • DCF dose-dependently disrupted host fatty acids and glucose metabolism of mice. • DCF dose-dependently altered microbial composition with inhibition of bacterial fermentation. [ABSTRACT FROM AUTHOR]

Pesticides, organochlorines, analogues and derivatives of DDT, those are all terms often associated with health risks, intoxications, nephropathies and other hepatotoxicities. These are phytosanitary products that interfere with the internal metabolism of sensitive organs, such as the kidney or the liver, which orchestrate the metabolism and elimination of xenobiotics. In this study, a group of Wistar rats was intraperitoneally exposed to Dicofol, a pesticide analogue of DDT. A second group received preventive injections of a diluted thyme essential oil solution for four days before exposure to Dicofol. The evaluation of the toxic effects possibly induced by Dicofol in the two experimental groups was carried out using a multidisciplinary approach including clinical chemistry, histopathology and 1H-NMR-based metabonomics. Histopathological examination showed pulmonary inflammation and kidney damage in the group exposed to Dicofol. The metabonomic study revealed metabolic disturbances in the liver and kidney. The protective role of the essential oil of thyme was clearly demonstrated from the metabonomic profiles and was confirmed by histological examination of organs. [ABSTRACT FROM AUTHOR]

The metabolic ratio of (p,p'-DDE + p ,p - DDD)/p,p'-DDT or p,p'-DDE/p,p'-DDT has been used previously to estimate the approximate half-life of p,p'-DDT, with a relatively unclear concept of "old" and "new" sources of p,p'-DDT and without paying attention to the influence by dicofol-type DDT contributed from the more recent usage of dicofol. Based on the isomeric ratio of o,p'-DDT/p,p'-DDT to distinguish the sources of DDT, this study used the corrected metabolic ratio of (p,p'-DDE + p,p'-DDD)/p,p'-DDT to estimate a more accurate half-life of p,p'-DDT using a model-based approach. This indicates the average half-life of p,p'- DDT in Chinese topsoils was 14.2 ± 0.9 years with dicofol-type DDT input considered. In deeper soil, the half-life was >30 years and the metabolic pathway of p,p'-DDT was significantly different with topsoil's. Further analysis on the fraction of DDT from technical DDT suggested that a region that had been sprayed with technical DDT was likely to have been sprayed with dicofol as well, but the monitoring residues of DDT in topsoil mainly derive from historical use of technical DDT. [ABSTRACT FROM AUTHOR]

Recently incidence of Tetranychus urticae is a widespread issue in grape orchards in India. The possibility of a pesticide induced resurgence of mites was explored by applying field recommended doses of commonly used pesticides. The field trial revealed no resurgence with respect to dicofol, abamectin, spiromecifen, dichlorovos + fish oil resin soap, and dinocap usage consecutively. Sulphur induced heavy resurgence (16.55%) with resurgence ratio of 1.05, followed by thiamethoxam (8.89%), acetamiprid (6.97%), imidacloprid (6.15%) and buprofezin (5.46%) with resurgence ratios of 0.81, 0.89, 0.87, and 0.88 respectively. [ABSTRACT FROM AUTHOR]

In this paper we review a specific use of the dico form: its use as autonymous marker. From a corpus of Latin texts (from the archaic period to the Flavian Age), we try to determine if this use is correlated to specific linguistic configurations. After reminding that the dico form could be used in the self-quotation with different values (over-enunciative and autonymous) often connected with the morphosyntactic form of the quoted speech, we study more specifically the linguistic conditions of emergence of the dico form as autonymous marker and review different criteria: contextual, syntactic, semantic and pragmatic. In the last part of this paper, we propose to focus our attention on two particularly relevant phenomena: the autodiaphonic repetitions and the case particularities of the word used in autonymy with dico. [ABSTRACT FROM AUTHOR]

Organochlorine pesticides have generated growing concern owing to their diverse toxicities. In this connection, we have evaluated toxic potential of an acaricide, dicofol (DCF) and its harmful effects on human RBCs and lymphocytes. DCF caused hemolysis and rupture of human erythrocytes as confirmed by scanning electron microscopy (SEM). Significant increase in protein oxidation, lipid peroxidation, ROS production, methemoglobin formation with enhanced activities of superoxide dismutase and catalase but decreased level of reduced glutathione were observed as a result of DCF exposure to human erythrocytes. SEM showed significant DCF induced alterations in RBCs from normal discoid shape to echinocytes. Similarly, lymphocytes showed membrane damage, formation of membrane blebs and distorted cell morphology. In vitro comet assay indicated a significant DNA fragmentation in human lymphocytes upon DCF exposure. These results strongly suggest that DCF induces oxidative stress in RBCs via generation of ROS and alters the cellular architecture directly and indirectly. [ABSTRACT FROM AUTHOR]

Dicofol application may be an important source to elevate the dichlorodiphenyltrichloroethane (DDT) residues to soils in Fujian, Southeast China, after the technical DDT was banned, which left DDT residues from the historical application. The DDT residues varied geographically, corresponding to the varied potential sources of DDT. In this study, a novel approach based on the Bayesian method (BM) was developed to identify the source contributions of DDT to soils, composed with both historical DDT and dicofol. The Naive Bayesian classifier was used basing on the subset of the samples, which were determined by chemical analysis independent of the Bayesian approach. The results show that BM (95%) was higher than that using the ratio of o, p ′-/ p, p ′-DDT (84%) to identify DDT source contributions. High detection rate (97%) of dicofol ( p, p ′-OH-DDT) was observed in the subset, showing dicofol application influenced the DDX levels in soils in Fujian. However, the contribution from historical technical DDT source was greater than that from dicofol in Fujian, indicating historical technical DDT was still an important pollution source to soils. In addition, both the DDX (DDT isomers and derivatives) level and dicofol contribution in non-agricultural soils were higher than other agricultural land uses, especially in hilly regions, the potential cause may be the atmospheric transport of dicofol type DDT, after spraying during daytime, or regional difference on production and application. [ABSTRACT FROM AUTHOR]

The acaricide, dicofol, is a well-known pesticide and partly a substitute for dichlorodiphenyltrichloroethane (DDT). Only few reports on environmental occurrence and concentrations have been reported calling for improvements. Hence, an analytical method was further developed for dicofol and dichlorobenzophenone (DCBP) to enable assessments of their environmental occurrence. Concentrated sulfuric acid was used to remove lipids and to separate dicofol from DCBP. On-column injection was used as an alternative to splitless injection to protect dicofol from thermal decomposition. By the method presented herein, it is possible to quantify dicofol and DCBP in the same samples. Arctic cod ( Gadus morhua) were spiked at two dose levels and the recoveries were determined. The mean recovery for dicofol was 65% at the low dose (1 ng) and 77% at the high dose (10 ng). The mean recovery for DCBP was 99% at the low dose (9.2 ng) and 146% at the high dose (46 ng). The method may be further improved by use of another lipid removal method, e.g., gel permeation chromatography. The method implies a step forward in dicofol environmental assessments. [ABSTRACT FROM AUTHOR]

Dicofol has been widely used to control phytophagous mites. Although dicofol is chemically related to DDT, its mode of action has remained elusive. Here, we mapped dicofol resistance in the spider mite Tetranychus urticae to two genomic regions. Each region harbored a glutamate-gated chloride channel (GluCl) gene that contained a mutation-G314D or G326E-known to confer resistance against the unrelated acaricide abamectin. Using electrophysiology assays we showed that dicofol and other diphenylcarbinol acaricides-bromopropylate and chlorobenzilate-induce persistent currents in Xenopus oocytes expressing wild-type T. urticae GluCl3 receptors and potentiate glutamate responses. In contrast, the G326E substitution abolished the agonistic activity of all three compounds. Assays with the wild-type Drosophila GluClα revealed that this receptor was unresponsive to dicofol. Homology modeling combined with ligand-docking confirmed the specificity of electrophysiology assays. Altogether, this work elucidates the mode of action of diphenylcarbinols as mite-specific agonists of GluCl., (© 2023. The Author(s).)

Pesticides are toxic and could negatively impact humans and the ecosystem. The Kitchener Drain is among the longest drains in Egypt and carries a wide range of wastewater from the agriculture sector, which contains pesticides and may pollute the ecosystem. Thus, water quality, human health risk, and pesticide accumulation in African catfish and Nile tilapia from the Kitchener Drain-Egypt. The water and fish samples were collected from Kitchener Drain in Kafr Elsheikh Governorate, Egypt, during the four seasons. The results indicated that heptachlor and diazinon were undetected during the four seasons. However, endosulfan, chlorpyrifos, and dicofol were detected in winter and autumn. Only p,p'-DDT was detected during spring. Endosulfan, heptachlor, and aldrin were detected in Nile tilapia during winter. Only heptachlor and aldrin were detected during spring. Endosulfan, heptachlor, dicofol, p,p'-DDT, chlorpyrifos, and diazinon were detected in the autumn season. In summer, dicofol and p,p'-DDT were detected, while endosulfan, heptachlor p,p'-DDT, aldrin, chlorpyrifos, and diazinon were not detected. In African catfish, endosulfan, heptachlor, dicofol, and p,p'-DDT were detected during winter, while chlorpyrifos, aldrin, and chlorpyrifos, aldrin, and diazinon were not detected. In the spring season, endosulfan, heptachlor, and aldrin were detected. Endosulfan, heptachlor, dicofol, p,p'-DDT, aldrin, chlorpyrifos, and diazinon were detected in the autumn season. Similarly, in the summer season, endosulfan, heptachlor, dicofol, p,p'-DDT, aldrin, chlorpyrifos, and diazinon were detected. The sequence of estimated daily intake (EDI) in Nile tilapia during the four seasons is heptachlor > endosulfan > dicofol > p,p'-DDT > aldrin > diazinon > chlorpyrifos. The sequence of EDI in African catfish during the four seasons is endosulfan > p,p'-DDT > heptachlor > aldrin > dicofol > diazinon > chlorpyrifos. In conclusion, the results confirmed the absence of a hazard index for consuming Nile tilapia and African catfish collected from the Kitchener drain., (© 2023. The Author(s).)

Field trials were conducted consecutively for three years at AICRP Fruit Research Centre, Sabour, Bhagalpur, Bihar to develop eco-friendly, sustainable pest management approaches against litchi mite. Experimental results revealed that the treatment 2 comprising pruning of infested litchi twigs in June followed by spraying of dicofol @ 0.05% found to be the most effective in reduction (58.28%) of litchi mite infestation as compared to other treatments. In addition to, it also obtained highest (44.24 kg/tree) yield and cost benefit ratio (1:5.78) than others. The next best treatment was T5 comprised pruning of infested litchi twigs in June followed by spraying of dimethoate @0.05% (42.63% reduction of litchi mite infestation and yield: 39.63 kg/tree). The information generated under the study can be incorporated in the pest management modules of litchi without disturbing the ecology of natural enemy and cropping system. [ABSTRACT FROM AUTHOR]

Conventional acaricide Dicofol 18.5EC along with novel acaricides Propargite 57EC, Clofentazine 50EC, Cyflmetofen 20SC, Fenproximate 5EC, Dicofol 18.5EC and botanical Azadirachtin 0.03EC were evaluated against T. neocaledonicus on brinjal in laboratory and in field condition on brinjal crop var. Punjab Sadabahar. Fenproximate 5EC was most toxic with lowest LC50 value 7.095ppm, followed by Dicofol 18.5 EC 20.971ppm, Cyflumetofen 20SC 22.53ppm, Clofentazine 50SC 87.20ppm, Propargite 57 EC 108.62ppm and least was Azadirachtin 0.03 EC 319.35ppm. Relative toxicities of Fenproximate 5EC, Cyflumetofen 20SC, Clofentazine 50SC, Propargite57 EC, Azadirachtin 0.03 EC and Dicofol 18.5 EC was 2.955, 0.930, 0.240, 0.193, 0.065 and 1.00 respectively. The mean percent mortality of T. neocaledonicus in field condition was highest that of Clofentazine 80.36 &73.07 percent followed by 59.28 & 62.29 percent by Fenproximate, 53.83 & 57.85 percent by Cyflumetofen, 51.38 & 60.77 percent by Propargite, 50.56 & 52.3 by Dicofol and lastly 25.22 & 33.81 percent mortality by Azadirachtin in first and second spray. All the acaricides proved superior over control and gave protection to the crop upto 14 days after spray and the novel acaricides were much effective over standard acaricide Dicofol in field condition. [ABSTRACT FROM AUTHOR]

We collected and analyzed 128 surface soil samples from Xiangfen County for dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethane (DDD), and dichlorodiphenyldichloroethylene (DDE). Total DDT concentrations (DDTs; sum of p,p′ -DDD, p,p′ -DDE, and p,p′ -DDT) ranged from ND to 427.81 ng g −1 (dry weight, dw), with a mean of 40.26 ng g −1 (dw). Among the three compounds, p,p′ -DDD was the most dominant. The DDTs in Xiangfen County soils mainly originated from historical DDT use, but there were also new inputs likely related to dicofol use. The DDTs in Xiangfen County soils were mainly degraded under anaerobic conditions, and direct degradation to DDD was the main degradation route. Regions with relatively high concentrations of DDTs were mainly located in North and South Xiangfen County. In these regions, many soil samples contained p,p′ -DDT as the predominant pollutant, suggestive of extensive new inputs of DDT. A health risk assessment revealed that there are no serious long-term health impacts of exposure to DDTs in soil, for adults or children. [ABSTRACT FROM AUTHOR]

We present novel magnetic composite nanospheres for the preparation of a nanoiron oxide/carbon dots/β-cyclodextrin/molecularly imprinted polymer for the selective solid-phase extraction kelthane and pyridaben from vegetables. The molecularly imprinted polymer was synthesized on the surface of nano-iron oxide/carbon dots via a chemical polymerization procedure, where kelthane-β-cyclodextrin and pyridaben-β-cyclodextrin inclusion complexes were used as template molecules, and their adsorption behavior was investigated in detail. Characterization analysis and binding experiments revealed that magnetic composite nanospheres had outstanding magnetic properties, a large adsorption capacity, and high competitive selectivity for kelthane and pyridaben. The magnetic composite nanospheres were employed as an adsorbent in solid-phase extraction for the determination of kelthane and pyridaben in vegetable samples. The recoveries of kelthane and pyridaben were 92.8-105.2 and 94.4-104.6%, respectively. [ABSTRACT FROM AUTHOR]