Concentrations Of Chlorpyrifos Research Articles

Determination of Concentrations of Pesticide Residues in Chevon obtained from Abattoir of Jimeta, Adamawa State, Nigeria

The current work was aimed at determining levels of Organochlorine (OCP) and Organophosphorus pesticide (OPP) residues in goats obtained from the study area. This was to enable the public aware of the presence of hazardous pesticides residues in the food chain. Forty samples were collected from; Chevon, intestines, kidneys and livers of ten sampled goats. The sampled goats were represented by G1 = first goat, G2 = second goat, G3 = third goat, G4 = fourth goat, G5 = fifth goat, G6 = sixth goat, G7 = seventh goat, G8 = eighth goat, G9 = ninth goat and G10 = tenth goat. Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) was used in preparing the samples. Analysis was done with Gas chromatography – Mass spectrometer (GC/MS) Acqmethod pesticide. Results showed that OCP residues were not detected in all the samples. Anthracene, dichlorpyrifos, diazinon, dimethoate, primifos-methyl, and malathion were detected below the threshold value of 0.001 mg/Kg. Likewise, all pesticide residues in G7 and G9 samples were below the threshold limit (0.001) mg/Kg. Dichlorvos wasdetected in chevon of G1, G3 and G4 with range from 0.043 mg/Kg in G4 – 0.113 mg/Kg in G1. Chlorpyrifos was detected in intestine of G1, G2, G3, G4, G6, G8 and G10. The highest was 0.051 mg/Kg in G4 and lowest was 0.013 mg/Kg in G10. Kidney samples of GI, G2, G3 and G4 contained chlorpyrifos ranging from 0.011 mg/Kg in G8 – 0053 mg/Kg in G4. dichlovos was detected in kidney samples of G1, G2, G3, G4 and G8. Highest concentration of dichlovos in the kidney was; 0.069 00014 mg/Kg in G1 while the lowest was in G8 (0.011mg/Kg). Liver samples of G2, G4, G6 and G10 contained chlopyrifos ranging from 0,007 mg/Kg in G10 – 0.050 mg/Kg in G4. dichlovos was present in livers of G2, G4 and G6. Highest was in G4 (0.037 mg/Kg) and lowest value was in G6 (0.021 mg/Kg). Apart from in Kidney of G8, concentrations of chlorpyrifos in all the samples were above the maximum residue level (MRL) values of 0.01 mg/Kg. Consumption of which may pose health problem. Concentration of dichlorvos detected in the samples were below the MRL of 1.00mg/Kg, this may not pose immediate health issues but continuous intake may bring about accumulative health risk issues. Keywords: Chevon, chlorpyrifos, dimethoate, organophosphorus, malathion, dichlorvos, health, risk

De novo transcriptome analysis of Protohermes xanthodes Navás (Megaloptera: Corydalidae) reveling the effects of sublethal chlorpyrifos on the expression of cholinergic neuronal genes

The insect cholinergic neuron system is the target for various pesticides, including organophosphate, carbamate and neonicotinoid pesticides. In this study, we conducted a de novo transcriptome analysis on the aquatic insect Protohermes xanthodes and identified for the first time presenting sixteen genes encoding cholinergic neuronal proteins (PxanChaT, PxanVAChT, PxanmAChR, PxannAChRs, and PxanAChEs), which are candidates for acetylcholine synthesis, transport, reception and degradation in cholinergic synapse. FPKM analysis revealed that these genes are primarily expressed in head and nerve cord of P. xanthodes larvae, and some of them are also abundant in hindgut, malpighian tubules and tracheae. After exposed to different concentrations of sublethal chlorpyrifos (CPF), expression of these cholinergic neuronal genes are generally increased and then decreased with the increase of CPF concentration, except PxannAChRα9 which is increased in both 4.2 and 8.4 μg/L CPF groups. Short-term (96 h) CPF exposure resulted in significant up-regulation of PxanAChE1 expression in P. xanthodes larvae exposed to 0.42 and 4.2 μg/L CPF concentrations, while PxanAChE2 was up-regulated only in 0.42 μg/L CPF group. After long-term (14 d) CPF exposure, PxanAChE1 expression was down-regulated in 0.168 and 0.42 μg/L CPF groups. PxanAChE2 expression was dramatically decreased in all CPF groups. Moreover, acetylcholinesterase (AChE) activity was significantly decreased across all long-term CPF exposure groups. These results suggested that sublethal exposure to CPF can disrupt the expression of cholinergic neuronal genes in P. xanthodes larvae, and implied that long-term sublethal CPF exposure may cause toxic effects on P. xanthodes larvae by inhibiting AChE activity. Furthermore, identification of cholinergic neuronal genes in P. xanthodes provided candidate molecular markers for study the toxic effects of environmental pollutants on the neuron system of an aquatic predatory insect with ecological importance.

Multi-biomarker approach to evaluate the toxicity of chlorpyrifos (active ingredient and a commercial formulation) on different stages of Biomphalaria straminea

Biomphalaria straminea is a freshwater gastropod native to South America and used in toxicological assessments. Our aim was to estimate 48 h-LC50 and sub-chronic effects after the exposure to low concentrations of chlorpyrifos as commercial formulation (CF) and active ingredient (AI) on B. straminea adult, embryos and juveniles. Concentrations between 1 and 5000 μg L−1 were chosen for acute exposures and 0.1 and 1 μg L−1 for the sub-chronic one. After 14 days biochemical parameters, viability and sub-populations of hemocytes, reproductive parameters, embryotoxicity and offspring' survival were studied. Egg masses laid between day 12 and 14 were separated to continue the exposure and the embryos were examined daily. Offspring' survival and morphological changes were registered for 14 days after hatching. 48 h-LC50, NOEC and LOEC were similar between CF and AI, however the CF caused more sub-lethal effects. CF but not the AI decreased carboxylesterases, catalase and the proportion of hyalinocytes with respect to the total hemocytes, and increased superoxide dismutase and the % of granulocytes with pseudopods. Also CF caused embryotoxicity probably due to the increase of embryos' membrane permeability. Acetylcholinesterase, superoxide dismutase, hemocytes sub-populations, the time and rate of hatching and juveniles' survival were the most sensitive biomarkers. We emphasize the importance of the assessment of a battery of biomarkers as a useful tool for toxicity studies including reproduction parameters and immunological responses. Also, we highlight the relevance of incorporating the evaluation of formulations in order to not underestimate the effects of pesticides on the environment.

Molecular docking analysis of chlorpyrifos at the human α7-nAChR and its potential relationship with neurocytoxicity in SH-SY5Y cells

The organophosphate insecticide chlorpyrifos (CPF), an acetylcholinesterase inhibitor, has raised serious concerns about human safety. Apart from inducing synaptic acetylcholine accumulation, CPF could also act at nicotinic acetylcholine receptors, like the α7-isoform (α7-nAChR), which could potentially be harmful to developing brains. Our aims were to use molecular docking to assess the binding interactions between CPF and α7-nAChR through, to test the neurocytotoxic and oxidative effects of very low concentrations of CPF on SH-SY5Y cells, and to hypothesize about the potential mediation of α7-nAChR. Docking analysis showed a significant binding affinity of CPH for the E fragment of the α7-nAChR (ΔGibbs: −5.63 to −6.85 Kcal/mol). According to the MTT- and Trypan Blue-based viability assays, commercial CPF showed concentration- and time-dependent neurotoxic effects at a concentration range (2.5–20 µM), ten-folds lower than those reported to have crucial effects for sheer CPF. A rise of the production of radical oxygen species (ROS) was seen at even lower concentrations (1–2.5 µM) of CPF after 24h. Notably, our docking analysis supports the antagonistic actions of CPF on α7-nAChR that were recently published. In conclusion, while α7-nAChR is responsible for neuronal survival and neurodevelopmental processes, its activity may also mediate the neurotoxicity of CPF.

A comparative study on targeted gene expression in zebrafish and its gill cell line exposed to chlorpyrifos.

Chlorpyrifos (CPF) is an organophosphorus-based insecticide, which is known to pose a serious risk to aquatic animals. However, the mechanisms of CPF toxicity in animals still remain unclear. The present investigation aimed to compare the potential effects of CPF in zebrafish (Danio rerio) and its gill cell line (DrG cells). Based on the in vivo study, the LC50 was calculated as 18.03µg/L and the chronic toxic effect of CPF was studied by exposing the fish to 1/10th (1.8µg/L) and 1/5th (3.6µg/L) of the LC50 value. Morphological changes were observed in fish and DrG cells which were exposed to sublethal concentrations of CPF. The results of MTT and NR assays showed significant decline in the survival of cells exposed to CPF at 96h. The production of reactive oxygen species in DrG cells and expression levels of antioxidant markers, inflammatory response genes (cox2a and cox2b), cyp1a, proapoptotic genes (bax), antiapoptotic gene (bcl2), apoptotic genes (cas3 and p53), and neuroprotective gene (ache) were determined in vivo using zebrafish and in vitro using DrG cells after exposure to CPF. Significant changes were found in the ROS production (DrG cells) and in the expression of inflammatory, proapoptotic, and apoptotic genes. This study showed that DrG cells are potential alternative tools to replace the use of whole fish for toxicological studies.

Occurrence and health risk of pesticide residues in Chinese herbal medicines from Shandong Province, China.

Pesticide residue was one of the stress factors affecting quality and safety of Chinese herbal medicines (CHMs). The present study was designed to investigate the occurrence and dietary exposure of 70 pesticide residues in 307 samples of CHMs, including 104 American ginseng, 100 Ganoderma lucidum (G. lucidum), and 103 Dendrobium officinale (D. officinale) in Shandong Province, China. The study revealed that a total of 29 pesticides were detected in the majority (92.5%) of samples, and the pesticide residues of 85 (27.7%) samples exceeded the maximum residue levels (MRLs). Particularly, the maximum concentration of chlorpyrifos was 23.8mgkg-1, almost 50 times of the MRLs in food in GB 2763-2021, while there's no standard restrictions specified in CHMs in China. The chronic, acute, and cumulative risk assessment results indicated that risk exposure of the three types of CHMs were unlikely to pose a health risk to consumers. However, more attention should be paid to the multiple residues with the presence of four or more pesticides in one sample and high over-standard rate of pesticides. The pesticide users and the government should pay more attention to the pesticides used in CHMs and regularly monitor the presence of these compounds. The study recommended the MRLs of these pesticides in CHMs should be established and perfected by the relevant departments in China.

Chlorpyrifos impairs sperm parameters and number of Sertoli and Leydig cells in rats after exposure during the peripubertal period

Chlorpyrifos is an organophosphate insecticide used to control pests in crops. Thus, humans are constantly exposed through ingestion of contaminated food or water, inhalation of contaminated air, and through the skin. The juvenile and peripubertal periods comprise a window of development of the reproductive system, sensitive to toxic agents. Considering the scarcity of data on exposure to the insecticide during these periods, the aim of this study was to evaluate the effects of chlorpyrifos on the testis during the juvenile and peripubertal periods. Thirty Wistar rats with an initial age of 25 days were distributed into 3 groups: control, which received corn oil (vehicle); CPS5, which received 5 mg/Kg b.w. of chlorpyrifos; and CPS15, which received 15 mg/Kg b.w. of chlorpyrifos. The groups were treated via gavage daily for 40 days and on the 41st experimental day, the animals were anesthetized and submitted to euthanasia to collect the organs. Blood was collected to obtain plasma and testosterone measurement. The testicles were removed, weighed and used for sperm count analyses, histopathological and morphometric analyzes and for oxidative stress analyses. Spermatozoa from the vas deferens were collected for analyzes of sperm morphology and acrosome integrity. The results showed that the two concentrations of chlorpyrifos caused a decrease in the number of Leydig and Sertoli cells and germ cells and increased the number of morphologically abnormal sperm and sperm with acrosomal damage. Furthermore, a decrease in lipid peroxidation was observed in the CPS5 and CPS15 groups, and a decrease in glutathione-S-transferase activity in the CPS5 group. We conclude that exposure to chlorpyrifos harms the daily production of sperm, as well as their quality, in addition to causing an imbalance in the oxidoreductive balance of the testicle.

Effect of chlorpyrifos-exposure on the expression levels of CYP genes in Daphnia magna and examination of a possibility that an up-regulated clan 3 CYP, CYP360A8, reacts with pesticides.

Daphnia magna is a test organism used for ecological risk assessments of pesticides, but little is known about the expression levels of cytochrome P450s (CYP)s and their changes after pesticide exposure in the less than 24-h-olds used for ecotoxicity tests. In this study, D. magna juveniles were exposed to 0.2 μg/L of chlorpyrifos under the conditions for acute immobilization test as specified by the OECD test guideline for 24 h, and then the gene expression was compared between the control and chlorpyrifos-exposure groups by RNA-sequencing analysis, with a focus on CYP genes. Among 38 CYP genes expressed in the control group, seven were significantly up-regulated while two were significantly down-regulated in the chlorpyrifos-exposure group. Although the sublethal concentration of chlorpyrifos did not change their expression levels so drastically (0.8 < fold change < 2.6), CY360A8 of D. magna (DmCYP360A8), which had been proposed to be responsible for metabolism of xenobiotics, was abundantly expressed in controls yet up-regulated by chlorpyrifos. Therefore, homology modeling of DmCYP360A8 was performed based on the amino acid sequence, and then molecular docking simulations with the insecticides that were indicated to be metabolized by CYPs in D. magna were conducted. The results indicated that DmCYP360A8 could contribute to the metabolism of diazinon and chlorfenapyr but not chlorpyrifos. These findings suggest that chlorpyrifos is probably detoxified by other CYP(s) including up-regulated and/or constitutively expressed one(s).

Biosynthesized CS-MgO/zeolite hybrid material: An efficient adsorbent for chlorpyrifos removal - Kinetic studies and response surface methodology

The prevalence of organophosphate pesticides in aquatic environments raises severe concerns on a global scale. Chlorpyrifos, an insecticide, is included in a class of organophosphate pesticides. It is widely used on agricultural lands to control pests in cotton, fruit, and vegetables. The acute toxicity of chlorpyrifos is still dangerous to all aquatic living organisms. Then the treatment of water contaminated with chlorpyrifos is an important aspect. The recent decade has witnessed adsorption technology emerging as an advanced organophosphate pesticide wastewater treatment with great potential and a grand blueprint, in which the specific surface area and active sites of the adsorbent are considered to be the two most important characteristics largely impacting the adsorption performance. In this study, a CS-MgO/Zeolite composite was prepared by the microbial method as an effective adsorbent for the removal of chlorpyrifos from an aqueous solution. The adsorbent's properties were carefully characterized using X-ray diffraction, scanning electron microscopy, and Fourier-transform infrared spectroscopy. The refinement of experimental conditions, encompassing variations in adsorbent dosage, contact time, and chlorpyrifos concentration at five discrete levels, was systematically undertaken through the utilization of a composite central design rooted in response surface methodology. The solution pH played a key role in chlorpyrifos removal, and a pH of 7.0 was selected according to its high adsorption ability. The highest removal (80.9%) of chlorpyrifos by CS-MgO/Zeolite was obtained at an optimum pH of 7, a contact time of 40 min, an adsorbent dosage of 0.4 g/L, and a chlorpyrifos concentration of 5 mg/L−1. The adsorption results were highly fitted with the Freundlich adsorption isotherm model, and the maximum adsorption was 83.3 mg/g. Kinetic studies indicate that the removal of chlorpyrifos followed the pseudo-second-order model of adsorption (0.994). The thermodynamic parameters indicate the spontaneous and endothermic nature of chlorpyrifos sorption on CS-MgO/Zeolite sorbent. The results revealed that introducing chitosan could improve the adsorption capacity and rate effectively even though it sacrificed part of the specific surface areas of the MgO/Zeolite, indicating that active sites might play a dominant role during chlorpyrifos adsorption. The fabricated CS-MgO/Zeolite adsorbent nanocomposite displayed high reusability based on the elution and simultaneous regeneration ability. Therefore, as a cheap green nanocomposite adsorbent with high adsorption performance for chlorpyrifos, the CS-MgO/Zeolite nanocomposite adsorbent is expected to become one of the best candidate materials for chlorpyrifos removal aqueous solutions.

Relative gene expression analysis of catalase in environmental RNA from Japanese medaka exposed to toxic chemicals

AbstractEnvironmental RNA (eRNA) has the potential as a non‐invasive tool for assessing the physiological status of macro‐organisms, yet the quantitative method for relative gene expression analysis is still underexplored. To bridge this gap, this study introduces a relative quantification method for eRNA, employing quantitative PCR (qPCR) to evaluate the expression of the antioxidant gene, catalase (cat), in the Japanese medaka Oryzias latipes exposed to two toxic chemicals for 96 h: chlorpyrifos (CPS) and carbamazepine. Our results showed that, in eRNA, genes frequently used as a reference for tissue or cells in conventional expression analysis correlated with each other. Also, one of them (elfa) exhibited less variability, showing its potential suitability as a reference gene in eRNA analyses. Additionally, cat expression levels in eRNA increased with increasing CPS concentrations, in a concentration‐response manner. These results suggest the promising potential of qPCR applications for eRNA in the monitoring of an organism's health and response to environmental changes. However, we observed disparities in gene expression levels of cat and beta‐actin (actb) between eRNA and whole fish body, indicating eRNA might have a biased origin. Further research is needed to uncover the origin of eRNA and determine the limitations and applicability domain of eRNA analysis.

Biodegradation of Chlorpyrifos Insecticide by Bacillus cereus ST06 and Chryseobacterium sp 6024 Isolated from Agricultural Soil, Nigeria

Introduction: Indigenous soil bacteria have the potential to degrade the harmful chlorpyrifos insecticide, this identifies the importance of biodegradation as an eco-friendly method for chemical pollutant cleanup.&#x0D; Aims: To compare the potential of Bacillus cereus ST06 and Chryseobacterium sp 6024 in biodegrading chlorpyrifos insecticide singly or as a consortium in a liquid medium.&#x0D; Study Design: Enrichment culture technique was used to evaluate the bacterial potential in biodegrading chlorpyrifos insecticide.&#x0D; Place and Duration of Study: Agricultural soil sample containing chlorpyrifos degrading bacteria was obtained from Ukukwa village Amansea Nigeria (6o16' 30'' N and 7o 07'30''E) from depths of 15cm. Experiment was conducted from January till March 2022.&#x0D; Methodology: In this study, previously isolated and characterized Bacillus cereus ST06 and Chryseobacterium sp 6024 by standard microbiological method based on their phenotypic test, biochemical test, cultural morphology and 16S rRNA sequencing was used for the experiment. Their growth response to 20mg/l and 60mg/l chlorpyrifos in mineral salts medium singly and as a consortium was compared and determined by monitoring the optical density at 600nm at the optimum condition of pH 6.5 and 30oC temperature for 28 days. The residual chlorpyrifos concentration after 28 days was also compared and determined using Gas Chromatography- Electron Cathode Detector (GC-ECD).&#x0D; Results: The result showed a significant difference (P&lt; .001) as Bacillus cereus ST06 and Chryseobacterium sp 6024 responded differently to different concentration of chlorpyrifos. Bacillus cereus ST06 and Chryseobacterium sp 6024 reached maximum growth in medium containing 20mg/l chlorpyrifos with a mean OD of 0.23±0.20 and 0.42±0.02 respectively on 16th day than 60mg/l chlorpyrifos with a mean OD of 0.47±0.02 and 0.81±0.02 respectively on 20th day. The bacterial consortium also reached maximum growth on 20mg/l and 60mg/l of chlorpyrifos with mean OD of 0.21±0.31 and 0.29±0.02 on 20th day respectively. The result of residual chlorpyrifos concentration shows that the bacteria consortium degraded 79 per cent and 78 per cent of 20mg/l and 60mg/l chlorpyrifos respectively, while Bacillus cereus ST06 and Chryseobacterium sp 6024 degraded 63 per cent and 57 per cent of 20mg/l chlorpyrifos and 61 per cent and 37 per cent of 60mg/l chlorpyrifos.&#x0D; Conclusion: The study shows that bacteria consortium possessed potential to be used in biodegradation of 20mg/l and 60mg/l Chlorpyrifos than the individual isolates. It is therefore recommended that further studies on RNA profiling of each bacterium and synergistic interaction of the bacterial consortium be studied to better understand regulation of genes and individual bacterial roles in degradation chlorpyrifos efficiently.

Preparation and Property Characterization of Eu2SmSbO7/ZnBiEuO4 Heterojunction Photocatalysts and Photocatalytic Degradation of Chlorpyrifos under Visible Light Irradiation

Eu2SmSbO7 and ZnBiEuO4 were synthesized for the first time using the hydrothermal method. Eu2SmSbO7/ZnBiEuO4 heterojunction photocatalyst (EZHP) was synthesized for the first time using the solvothermal method. The crystal cell parameter of Eu2SmSbO7 was 10.5547 Å. The band gap width of Eu2SmSbO7 was measured and found to be 2.881 eV. The band gap width of ZnBiEuO4 was measured and found to be 2.571 eV. EZHP efficiently degraded the pesticide chlorpyrifos under visible light irradiation (VLID). After VLID of 160 min, the conversion rate of the chlorpyrifos concentration reached 100%, while the conversion rate of the total organic carbon (TOC) concentration was 98.02% using EZHP. After VLID of 160 min, the photocatalytic degradation conversion rates of chlorpyrifos using EZHP were 1.13 times, 1.19 times, and 2.84 times those using Eu2SmSbO7, ZnBiEuO4, and nitrogen-doped titanium dioxide (N-doped TiO2), respectively. The photocatalytic activity could be ranked as follows: EZHP &gt; Eu2SmSbO7 &gt; ZnBiEuO4 &gt; N-doped TiO2. The conversion rates of chlorpyrifos were 98.16%, 97.03%, 96.03%, and 95.06% for four cycles of experiments after VLID of 160 min using EZHP. This indicated that EZHP was stable and could be reused. In addition, the experiments with the addition of capture agents demonstrated that the oxidation removal ability of three oxidation free radicals for degrading chlorpyrifos obeyed the following order: hydroxyl radical &gt; superoxide anion &gt; holes. This study examined the intermediates of chlorpyrifos during the photocatalytic degradation of chlorpyrifos, and a degradation path was proposed, at the same time, the degradation mechanism of chlorpyrifos was revealed. This study provides a scientific basis for the development of efficient heterojunction photocatalysts.

Chlorpyrifos Pesticide Removal from Black Grapes Using Plasma-Activated Water Produced by Plasma Bubbling Technology

This study is aimed at evaluating the ability of plasma-activated water (PAW) to reduce the chlorpyrifos pesticide residue in black grapes. Raw black grapes were spiked with a known concentration (10, 15, and 20 ppm) of chlorpyrifos (20% EC) and bubbled with 120 V air plasma at three different time intervals (5, 10, and 15 min). GC-MS analysis of these plasma-bubbled grapes showed up to 65.25% reduction (20 ppm sample) in chlorpyrifos content after 15 min of treatment. However, the treatment also reduced the grape juice’s ascorbic acid (19.97±2.69 to 9.15±2.02 mg/ml), antioxidant scavenging activity (77.42±2.97 to 53.30±4.77%), total flavonoids (3.00±0.53 to 2.61±0.57 mg QE/ml), total soluble solids (14.23±1.96 to 11.95±1.86°), total suspended solids (1.95±0.16 to 1.80±0.03 g/l), and turbidity (246.63±11.42 to 224.1±24.85 NTU). Meanwhile, other physicochemical attributes such as pH, titrable acidity, total phenol content, color index, and texture values had slight changes after plasma bubbling. Thus, plasma bubbling proved to be an effective method to remove the chlorpyrifos pesticide present in grapes, and the techniques also preserve the quality of the commodity.

Biodegradation of chlorpyrifos by charcoal–alginate immobilized bacterial consortium isolated from pesticide-polluted Kuzhikandam Creek, Kerala, India

Chlorpyrifos, one of the most frequent organophosphorus pesticides, has been linked to major health problems and widespread environmental degradation. It is imperative to remove this herbicide from its point source of contamination since the risk of their off-site migration poses a health concern to non-target organisms. The objective of the present study was to investigate the biodegradation of chlorpyrifos 20% emulsifiable concentration (EC) utilizing a consortium of bacteria that had previously been isolated from a pesticide-contaminated site and are chlorpyrifos tolerant (S27I and S28I). Free cells and immobilized cells with chlorpyrifos as the only carbon source were used to analyze the biodegradation. Charcoal–alginate and kaolin–alginate were the immobilization matrices employed in the investigation. By using gas chromatography-mass spectrophotometer analysis, the degradation of chlorpyrifos was investigated. When compared to free cells, immobilized bacterial isolates showed the greatest amount of biodegradation in the investigation. Consortium (C1) among the isolates degraded chlorpyrifos most quickly compared to S27I and S28I. The study also examined the toxicity of chlorpyrifos at doses of 10, 25, 50, 75, and 100 ppm on the green gram seeds’ morphological parameters. Increased chlorpyrifos concentrations resulted in appreciable variations in the germination percentage, shoot length, and root length. The green gram germination study was used to evaluate the detoxification of chlorpyrifos following its breakdown.

Resilience of aerobic sludge biomass under chlorpyrifos stress and its recovery potential

Non-agricultural sources of pesticides in urban areas are responsible for their presence in domestic wastewater. Therefore, pesticides are typically found in sewage treatment plants in developed and developing countries as micro-pollutant. The presence of pesticides in the wastewater can impart stress on the aerobic sludge biomass and disrupt the functioning of the plant. However, there exists a knowledge gap regarding the resilience of aerobic sludge biomass towards stress due to the presence of pesticides in the wastewater. This study investigated the impact of chlorpyrifos (CPS) – a widely used pesticide, on sludge biomass and explored its recovery capability when CPS is discontinued in the influent. Four duplicate reactors were operated with different CPS concentrations ranging from 50 to 200 mg/L. Chemical oxygen demand (COD) removal for reactors has ranged within 18–73 % at the steady state of the stressed phase, whereas COD removal for the control reactor was 91 %. CPS stress slightly inhibited filamentous biomass growth. Biomass activity and cell viability have decreased significantly, whereas biochemical contents have varied slightly under CPS stress. The activities of the enzymes dehydrogenase and urease were significantly inhibited when compared to catalase and protease. Amplified ribosomal DNA restriction analysis reflected changes in the microbial community. The discontinuation of CPS has allowed aerobic sludge biomass to recover in its organic degradation capability (COD removal of more than 88 % at steady-state conditions of recovery phase operation), biomass growth, and cell viability. In addition, enzyme activities have retrieved to their original levels, and 78–93 % similarity of microbial community structure has been displayed between CPS-exposed and control reactor biomasses. Overall, the present study has indicated the orderly changes in the quality of aerobic sludge biomass under CPS stress through physico-chemical and biological characteristics. The study also has highlighted the self-recovery of sludge biomass characteristics stressed with different concentrations of CPS.

Optimization of Growth Conditions for Chlorpyrifos-Degrading Bacteria in Farm Soils in Nakuru County, Kenya.

Chlorpyrifos (CP) is a chlorinated organophosphate pesticide. In Kenya, it is commonly used as an acaricide, particularly in dairy farming, leading to soil and water contamination. The study is aimed at isolating bacteria with CP-degrading potential and optimizing their growth conditions, including temperature, pH, and CP concentration. The enrichment culture technique was used, with minimal salt medium (MSM) supplemented with commercial grade CP. A multilevel factorial design was used to investigate the interactions of temperature, pH, and CP concentration. According to the findings, seven bacterial strains with potential to degrade CP were characterized and identified as Alcaligenes faecalis, Bacillus weihenstephanensis, Bacillus toyonensis, Alcaligenes sp. strain SCAU23, Pseudomonas sp. strain PB845W, Brevundimonas diminuta, and uncultured bacterium clone 99. Growth and biodegradation of bacteria differed significantly among the isolates across pH value, temperature, and concentrations (P ≤ 0.05). The optimum conditions for growth were pH 7, temperature of 25°C, and 25mg/l chlorpyrifos concentration, while optimum degradation conditions were pH 5, temp 25°C, and CP conc. 25mg/l. The Pearson correlation between optimum growth and degradation showed a weak positive relationship (R = 0.1144) for pH and strong positive relationship for temperature and concentration of chlorpyrifos. Other than pH, the study shows that there could be other cofactors facilitating the chlorpyrifos degradation process. The findings show that an efficient consortium, at 25°C and pH 5, can include Bacillus toyonensis 20SBZ2B and Alcaligenes sp. SCAU23 as they showed high optical density (OD) values under these conditions. These results indicate the potential for these bacteria to be employed in chlorpyrifos-contaminated ecosystem detoxification efforts upon manipulation of natural growth conditions. The findings of this study offer a potential foundation for future research into the reconstitution of a consortium. Based on the optimum conditions identified, the isolated bacterial strains could be further developed into a consortium to effectively degrade CP in both laboratory and field conditions. Dairy farmers can utilize the isolated strains and the consortia to decontaminate farm soils.

Modulation in growth, oxidative stress, photosynthesis, and morphology reveals higher toxicity of alpha-cypermethrin than chlorpyrifos towards a non-target green alga at high doses

Considering the frequent detection of pesticides in the aquatic environment, the ecotoxicological effects of Chlorpyrifos (CHP), an organophosphate, and alpha-cypermethrin (ACM), a pyrethroid, on freshwater microalgae were compared for the first time in this study. High concentrations of both CHP and ACM significantly suppressed the growth of test microalga Graesiella emersonii (p < 0.05). The 96-h EC50 of CHP and ACM were 54.42 mg L−1 and 29.40 mg L−1, respectively. Sub-inhibitory doses of both pesticides increased ROS formation in a concentration-dependent manner, which was accompanied by changes in antioxidant enzymes activities, lipid peroxidation, and variations in photosynthetic pigment concentration. Furthermore, both pesticides influenced photosystem II performance, oxygen-evolving complex efficiency and, intracellular ATP levels. Scanning electron microscopy analysis revealed that high concentrations of both CHP and ACM caused considerable morphological changes in the microalga. In comparison, CHP was more toxic than ACM at low concentrations, whereas ACM was more toxic at high concentrations.

Behavioral, Biometric and Oxidative Stress-Induced Alterations in Clarias gariepinus Juveniles Exposed to Chlorpyrifos

Chlorpyrifos is an organophosphate pesticide used to kill wide range of pest including insect and worms. The present study investigates the behavioral, biometric and oxidative stress alterations in Clarias gariepinus juveniles exposed to chlorpyrifos. The 96 h LC50 values of the pesticide estimated by probit analysis was 4.67 mg/L while the toxic unit was 21.41 indicating that the pesticide is very toxic. Fish were exposed to chlorpyrifos sublethal concentrations of 0.43 mg/L and 0.93 mg/L and the behavioral, biometric and oxidative stress parameters were determined on day 1, 5, 10, and 15. The results indicate changes in the behavior and hepatosomatic indices in C. gariepinus at different chlorpyrifos concentrations and time. There were concentration and duration dependent increase in lipid peroxidation, protein and glucose but mixed trends in catalase values. The use of chlopyrifos in the environment especially near aquatic ecosystem should be strictly monitored to avoid the hazards associated with its application.

Liver and kidney damage in quail embryos hatched from eggs sprayed once with chlorpyrifos during artificial incubation.

Birds have enough conditions to be used as bioindicators for the presence of environmental contaminants. Notably, chlorpyrifos (CPF) remains extensively employed in Argentina, particularly in fruit plantations and livestock settings This study aimed to assess the potential impacts of CPF on common quail (Coturnix coturnix) embryos through external eggshell application during key embryonic stages (days 1, 4, and 14). Concentrations equivalent to those used in fruit applications, 5× and 10 × (38.4, 192, and 384µg/egg), were employed. A 48% commercial formulation of CPF (Pirfos - Icona®) was utilized. An increase in embryonic deaths, as well as a statistical association between the degree of liver or kidney lesions and CPF concentrations was observed. The results suggest that CPF can induce embryotoxic effects with a single exposure to quail embryos and compromise the viability of the organisms. The study suggests a potential exposure risk for embryos through contact with the insecticide on the eggshell's exterior.

Recovery of Fish Community Suffered from Feminization by Endocrine Disrupting Chemicals (EDCs) in Surabaya River, East Java

There had been reports of a significant increase in female fish populations in the Surabaya River, induced by water pollution. This research aims to study the current sex condition and the level of Endocrine Disrupter Chemicals (EDC) in the river fishes after the river cleaning program promoted by the municipality. 420 fish samples from various species were taken from the river during 2017-2018. The fishes were sexed and analyzed their contents of estradiol, phthalate, and chlorpyrifos. The average sex ratio found was nearly normal (Male: Female=52:48), recovered significantly from the previous record in 2013 (16:84). Meanwhile the concentrations of EDC estradiol, phthalate, and chlorpyrifos found were 0.000; 0.033; and 0.037 mg/kg subsequently; except for chlorpyrifos, most of the chemicals were below the residue maximum limit by Indonesia National Standard (SNI).