Scenario of organophosphate pollution and toxicity in India: A review

Comprehensive multi-omics investigation of sub-chronic toxicity induced by Cadmium and Triazophos Co-exposure in hook snout carps (Opsariichthys bidens)

The coexistence of heavy metals and pesticides poses a critical challenge in agricultural ecosystems. Traditional toxicity assessments often focus only on the individual impacts of either pesticides or heavy metals. Here, the untargeted metabolomics and 16 S rRNA sequencing were used to assess the individual and combined effects of cadmium (Cd) and triazophos (TRI) on hook snout carps (Opsariichthys bidens). Cd caused much more serious impacts on hepatic metabolism and gut microbiota than those in TRI. Combined Cd and TRI exposure synergistically affected hepatic metabolism, causing mitochondrial dysfunction and even oxidative damage. Simultaneously, 16 S rRNA sequencing highlighted significant variations in the composition and abundance of gut microbiota. A noteworthy connection emerged between these distinct microbiota profiles and disruptions in energy metabolism, ultimately leading to disorders in metabolites. These findings enhanced the understanding of risks posed by heavy metals and pesticides, providing insights for better environmental risk assessments of aquatic organisms.

Lambda-Cyhalothrin induced behavioural, neurotoxic and oxidative stress on vertebrate model Danio rerio (Hamilton-Buchanan 1822)

λ-cyhalothrin, a synthetic type II pyrethroid, has become increasingly popular for control of aphids, butterfly larvae, and beetles, replacing other agricultural chemicals. As a result of which, residues of this synthetic pesticide are being reported across the globe in natural water, which poses a serious threat to aquatic life. Therefore, the present study was designed to understand the toxicity effects of λ-cyhalothrin on behaviour, oxidative stress and neurotoxicity in a vertebrate aquatic model, zebrafish (Danio rerio). The fish were exposed to 0.129, 0.194 and 0.388 µg/L corresponding to 5%, 10% and 20% of 96hLC50 (1.94 µg/L) for 28 days. Upon exposure to the highest concentration (0.388 µg/L), the test animal exhibited significant alterations in behavioural patterns like number of entries to the top zone (n), decrease in average speed (m/s) and decrease in time spent in top zone (s). Moreover, the shoaling test demonstrated a significant decrease (p < 0.05) in the relative time spent by the tested fish (%) near the stimulus fish. The change in behavioural alterations might be linked to a significant decrease (p < 0.05) in the brain acetylcholine esterase activity. Furthermore, the present study also illustrates oxidative stress exerted by λ-cyhalothrin through an increase in the production of reactive oxygen species, which is again clearly depicted by a significant increase (p < 0.05) in Superoxide dismutase, Catalase and Glutathione peroxidase activities. Overall, the present study systematically demonstrates the chronic effects of λ-cyhalothrin on adult fish behaviour and physiology, which will contribute to assessing the risks of λ-cyhalothrin to organismal health.

Fungicide-albumin interactions: unraveling the complex relationship-a comprehensive review

This review will give an insight into the interactions of serum albumins, which are proteins found in the blood, with fungicides. There are molecular interactions between several fungicides and two serum albumin proteins: human serum albumin (HSA) and bovine serum albumin (BSA). The main objective of this review is to through some light on the interactions of the fungicides with serum albumins and to highlight their toxicity level. The interactions of serum albumins with fungicides are complex and can be affected by the properties of the proteins themselves. This review provides valuable insight into the interactions between serum albumins and fungicides, which can help to know the efficacy and mechanism of fungicides and may help in designing new fungicides with low or no toxicity.

Bioremediation and bioscavenging for elimination of organophosphorus threats: An approach using enzymatic advancements

Organophosphorus compounds (OP) are highly toxic pesticides and nerve agents widely used in agriculture and chemical warfare. The extensive use of these chemicals has severe environmental implications, such as contamination of soil, water bodies, and food chains, thus endangering ecosystems and biodiversity. Plants absorb pesticide residues, which then enter the food chain and accumulate in the body fat of both humans and animals. Numerous human cases of OP poisoning have been linked to both acute and long-term exposure to these toxic OP compounds. These compounds inhibit the action of the acetylcholinesterase enzyme (AChE) by phosphorylation, which prevents the breakdown of acetylcholine (ACh) neurotransmitter into choline and acetate. Thus, it becomes vital to cleanse the environment from these chemicals utilizing various physical, chemical, and biological methods. Biological methods encompassing bioremediation using immobilized microbes and enzymes have emerged as environment-friendly and cost-effective approaches for pesticide removal. Cell/enzyme immobilized systems offer higher stability, reusability, and ease of product recovery, making them ideal tools for OP bioremediation. Interestingly, enzymatic bioscavengers (stoichiometric, pseudo-catalytic, and catalytic) play a vital role in detoxifying pesticides from the human body. Catalytic bioscavenging enzymes such as Organophosphate Hydrolase, Organophosphorus acid anhydrolase, and Paraoxonase 1 show high degradation efficiency within the animal body as well as in the environment. Moreover, these enzymes can also be employed to decontaminate pesticides from food, ensuring food safety and thus minimizing human exposure. This review aims to provide insights to potential collaborators in research organizations, government bodies, and industries to bring advancements in the field of bioremediation and bioscavenging technologies for the mitigation of OP-induced health hazards.

Non-enzymatic electrochemical impedance sensor for selective detection of electro-inactive organophosphate pesticides using Zr-MOF/ZrO2/MWCNT ternary composite

The existence of multiple pesticide residues in fruits and vegetables constitutes a direct peril to living organisms. Therefore, it is crucial to develop a low-cost screening method for determining organophosphate pesticides (OPPs) in food samples. This study describes the solvothermal synthesis of a ternary composite comprising multi-walled carbon nanotubes (MWCNT), zirconium oxide, and a zirconium-metal-organic framework (Zr-MOF). The ternary composite was characterised using XRD, FESEM, FTIR, and BET. The ternary composite provides a large surface area (1158 m2/g) compared with the pristine Zr-MOF (868 m2/g). The composite-modified glassy carbon electrode was used to determine nine pesticides, including organophosphate (malathion, dimethoate, chlorpyrifos, monocrotophos, and glyphosate) and non-organophosphate (thiophanate methyl, carbendazim, atrazine, and 2,4, D). In particular, various chemical combinations of OPPs were selected, such as S-P=S, P=S, P=O, and non-OPPs such as C=S (with sulphur), and without sulphur. The sensor results show that the sensor selectivity is high for OPPs containing both phosphorus and sulphur molecules. The low detection limit of the sensor was 2.02, 2.8, 2.5, 1.11, and 2.01 nM for malathion, chlorpyrifos, dimethoate, monocrotophos, and glyphosate, respectively. The electrode exhibited significant chemical stability (93%) after 100 cycles, good repeatability, and a long shelf life. The sensor is reliable for qualitative real-time applications.

Bioaccumulation of Chloropyrifos Organo-pesticide and Its Toxicogenic Association with Antioxidant GSTP1 in Pakistani Pest Control Workers

Synthetic pesticides are employed to enhance agricultural production. Chronic exposure to organophosphate (OP) pesticides may be a source of health problems. The present study was designed to examine an association of GSTP1 (rs1695) polymorphism with OP pesticide chronic exposure. A case-control study was recruited with 250 subjects comprising exposed (n = 100) and controls (n = 150). A survey was conducted to determine the pesticide type to which workers had exposed. According to recorded survey assessment, two compounds of OP pesticides chloropyrifos and malathion were investigated in the blood samples of exposed study subjects using high-performance liquid chromatography (HPLC). For screening of genetic polymorphism in GSTP1 (rs1695) polymerase chain reaction, restriction length polymorphism (PCR-RFLP) and agarose gel electrophoresis were performed. Statistically, data were analyzed using SPSS v. 20.0 and MedCal© software. Total chrom© navigator programmer was used for detection of OP residues in serum and local pesticide solution. chloropyrifos-OP pesticide residues were detected in serum of estimated chronically exposed subjects at 206 nm HPLC optimal conditions. The pattern of GSTP1 (rs1695) genotypic frequencies depicted that heterozygous genotype was higher in Chloropyrifos exposed subjects (0.56) when compared with controls (0.44). Statistical outcomes showed an insignificant association with GSTP1 (rs1695) polymorphism and chloropyrifos-OP pesticide toxicity (Fisher's exact test 1.0, p = 0.25). An insignificant allelic investigation reflected a protective effect of mutant allele G against chloropyrifos-OP pesticide toxicity in exposed subjects. Findings may be helpful in identifying bioaccumulated pesticide residues, but in studied Pakistani exposed workers, no significant association of GSTP1 (rs1695) variant with chloropyrifos-OPs was demonstrated.

First surveillance of pesticides in soils of the perimeter of Tadla, a Moroccan sugar beet intensive area

With the long-term application of pesticides on sugar beet farms in the irrigated perimeter of Tadla in Morocco for over 50 years, pesticide monitoring is necessary to assess soil health. The objective of our study was to monitor multiple pesticide residues in topsoil samples collected from post-harvest sugar beet fields and verify their migration to deep soil layers. Topsoil and deep soil samples were collected from arbitrarily selected sugar beet fields in the IPT. In this study, a target-screening method was applied. All target pesticides were detected in soil samples, with tefluthrin being the most frequently detected pesticide. The residue with the highest concentration in soil samples was DDE. All the soil samples contained a mixture of pesticide residues, with a maximum of 13 residues per sample. The total pesticide content decreased toward more profound layers of soil, except in one field where it reached a concentration of 348 µg/kg at the deeper soil layer. For pesticides detected at the three soil depths, only tefluthrin concentration increased in the deep soil layer. The results provide comprehensive and precise information on the pesticide residue status in sugar beet soils warning against the multiple risks that this contamination can cause. This study indicates the need of regular monitoring of pesticides over a large area of the perimeter to enable decision-makers to pronounce the impacts of the extension and intensification of sugar beet cultivation at the irrigated perimeter of Tadla.

Insight into the environmental fate, hazard, detection, and sustainable degradation technologies of chlorpyrifos-an organophosphorus pesticide

Pesticides play a critical role in terms of agricultural output nowadays. On top of that, pesticides provide economic support to our farmers. However, the usage of pesticides has created a public health issue and environmental hazard. Chlorpyrifos (CPY), an organophosphate pesticide, is extensively applied as an insecticide, acaricide, and termiticide against pests in various applications. Environmental pollution has occurred because of the widespread usage of CPY, harming several ecosystems, including soil, sediment, water, air, and biogeochemical cycles. While residual levels in soil, water, vegetables, foodstuffs, and human fluids have been discovered, CPY has also been found in the sediment, soil, and water. The irrefutable pieces of evidence indicate that CPY exposure inhibits the choline esterase enzyme, which impairs the ability of the body to use choline. As a result, neurological, immunological, and psychological consequences are seen in people and the natural environment. Several research studies have been conducted worldwide to identify and develop CPY remediation approaches and its derivatives from the environment. Currently, many detoxification methods are available for pesticides, such as CPY. However, recent research has shown that the breakdown of CPY using bacteria is the most proficient, cost-effective, and sustainable. This current article aims to outline relevant research events, summarize the possible breakdown of CPY into various compounds, and discuss analytical summaries of current research findings on bacterial degradation of CPY and the potential degradation mechanism.

Bioaccumulation of pesticides in fish resulting toxicities in humans through food chain and forensic aspects

A crucial component for agricultural productivity is pesticide application. Increased usage of pesticides has significantly increased agricultural output, reduced grain losses in storage, and overall enhanced human wellbeing. Globally, every year approximately 3 billion kg of pesticides are used which budgets around 40 billion USD. Pesticide use can leave behind unwanted residues that can contaminate food, the environment, and living tissues. They are known to spread from agricultural regions that have been treated into the wider environment, where they affect non-target creatures. All tiers of biological organisms, directly impacted by this exposure. Pesticides at sub-lethal levels alter every aspect of a fish's physiology, including histology, haematology, defence mechanisms, and behaviour. The same topic of pesticide toxicology is the emphasis of this article, which also addresses some important induced chronic toxicological effects of pesticides in fish and the extent of their bioaccumulation in fish tissues. The data represents the largest bodies of water, such as rivers and lakes, that have been contaminated by pesticides, notably due to pesticide drift. It has been discussed how readily pesticides are absorbed into fish bodies and how this enters the food chain inducing harmful impacts on human health when consumed.

Recent advances in the synthesis and applications of single-atom nanozymes in food safety monitoring

Nanozymes are synthetic compounds with enzyme-like tunable catalytic properties. The success of nanozymes for catalytic applications can be attributed to their small dimensions, cost-effective synthesis, appreciable stability, and scalability to molecular dimensions. The emergence of single atom nanozymes (SANzymes) has opened up new possibilities in bioanalytical applications. In this regard, this review outlines enzyme-mimicking features of SANzymes for food safety applications in relation to the key variables controlling their catalytic performance. The discussion is extended further to cover the applications of SANzymes for the monitoring of various compounds/biomaterials of significance with respect to food safety (e.g., pesticides, veterinary drug residues, foodborne pathogenic bacteria, mycotoxins/bacterial endotoxin, antioxidant residues, hydrogen peroxide residues, and heavy metal ions). Furthermore, the performance of SANzymes is evaluated in terms of various performance metrics such as limit of detection (LOD), linear dynamic range, and figure of merit (FoM). The challenges and future road map for the applications of SANzymes are also addressed along with their upscaling in the area of food safety.

Development and Validation of a New UFLC-MS/MS Method for the Detection of Organophosphate Pesticide Metabolites in Urine

To monitor human exposure to pesticides, experts commonly measure their metabolites in urine, particularly dialkyl phosphates (DAPs), which include diethyl phosphate (DEP), Diethyl thiophosphate (DETP), diethyl dithiophosphate (DEDTP), dimethyl phosphate (DMP), dimethyl thiophosphate (DMTP) and dimethyl dithiophosphate (DMDTP)to monitor the metabolites of organophosphates. These DAP metabolites are a urinary biomarker for assessing pesticide exposure and potential health risks. This study presented a new screening method combining ultrafast liquid chromatography with tandem mass spectrometry (UFLC-MS/MS) to detect six DAP metabolites in human urine. The study also compared standard sample extraction methods, namely, liquid-liquid extraction (LLE); quick, easy, cheap, effective, ruggedand safe (QuEChERS); and lyophilization. After a comprehensive analysis of the methods used to extract the analytes, including recovery rate, repeatability and reproducibility, the liquid-liquid extraction (LLE) method was found to be the best. It had a high recovery rate, was easy to handle, required less sample volume and had a short extraction time. Therefore, the LLE method was chosen for further analysis. The results showed excellent performance with high recoveries between 93% and 102%, precise repeatability (RSD) between 0.62% and 5.46% and acceptable reproducibility values (RSD) between 0.80% and 11.33%. The method also had limits of detection (LOD) ranging from 0.0201 ng/mL to 0.0697 ng/mL and limits of quantification (LOQ) ranging from 0.0609 ng/mL to 0.2112 ng/mL. Furthermore, the UFLC-MS/MS method was validated based on the SANTE guidance and successfully analyzed 150 urine samples from farmers and non-farmers. This validated method proved useful for biomonitoring studies focusing on OP pesticide exposure. It offers several advantages, such as a reduced need for samples, chemicals and materials, and a shorter analysis time. The method is sensitive and selective in detecting metabolites in human urine, making it a valuable approach for the practical and efficient assessment of pesticide exposure.

Comparison between pollutants found in breast milk and infant formula in the last decade: A review

Since ancient times, breastfeeding has been the fundamental way of nurturing the newborn. The benefits of breast milk are widely known, as it is a source of essential nutrients and provides immunological protection, as well as developmental benefits, among others. However, when breastfeeding is not possible, infant formula is the most appropriate alternative. Its composition meets the nutritional requirements of the infant, and its quality is subject to strict control by the authorities. Nonetheless, the presence of different pollutants has been detected in both matrices. Thus, the aim of the present review is to make a comparison between the findings in both breast milk and infant formula in terms of contaminants in the last decade, in order to choose the most convenient option depending on the environmental conditions. For that, the emerging pollutants including metals, chemical compounds derived from heat treatment, pharmaceutical drugs, mycotoxins, pesticides, packaging materials, and other contaminants were described. While in breast milk the most concerning contaminants found were metals and pesticides, in infant formula pollutants such as metals, mycotoxins, and packaging materials were the most outstanding. In conclusion, the convenience of using a feeding diet based on breast milk or either infant formula depends on the maternal environmental circumstances. However, it is important to take into account the immunological benefits of the breast milk compared to the infant formula, and the possibility of using breast milk in combination with infant formula when the nutritional requirements are not fulfilled only with the intake of breast milk. Therefore, more attention should be paid in terms of analyzing these conditions in each case to be able to make a proper decision, as it will vary depending on the maternal and newborn environment.

Enantioselectivity in the toxicological effects of chiral pesticides: A review

As a special category of pesticides, chiral pesticides have increased the difficulty in investigating pesticide toxicity. Based on their usage, chiral pesticides can be divided into insecticides, herbicides, and fungicides. Over the past decades, great efforts have been made on elucidating their toxicological effects. However, no literature has reviewed the enantioselective toxicity of chiral pesticides since 2014. In recent years, more chiral pesticides have been registered for application. As such, huge research progresses have been achieved in enantioselective toxicity of chiral pesticides. Generally, more researches have remedied the knowledge gap in toxicological effects of old and new chiral pesticides. And the toxicological endpoints being evaluated have become more specific rather than centering on basic toxicity and target organisms. Besides, the underlying mechanisms accounting for the enantioselectivity in toxicological effects of chiral pesticides have been discussed as well. All in all, this review provides the critical knowledge for risk assessments, and help to drive the green-technology of single- or enriched-enantiomer pesticides and formulation of relevant laws and regulations.

Geospatial assessment of variations in the heavy metals and pesticides concentration in the agricultural environment of Kasaragod District, Kerala, India

The impact of heavy metals and pesticides in our environment largely varies based on their chemical composition and the geographical conditions where they are present. This study assesses the variation in the concentration of heavy metals and pesticides in Kasaragod District, Kerala, Southern India. For the assessment, soil samples were collected from eight different locations of agricultural land during the three different seasons of 2017 and 2018. All the samples were tested for physicochemical characteristics, levels of heavy metals, and pesticides. The spatial distribution of trace metals and pesticides in the study area was performed by using the software Arc GIS, version 10.6. Significant variation in the physicochemical properties was observed during the different seasons. Similarly, the variation in the concentration of heavy metals in the soil ranged from 0.01 to 1018 [Formula: see text]g/kg. Among various heavy metals detected, aluminum (Al) was the most abundantly detected metal in the region of Malakallu, and cobalt (Co) was the scarcely detected metal in the region of Panathady. The average levels of organochlorine pesticides (OCPs) and organophosphorus pesticides (OPs) in the soil samples were from below detectable level (bdl) to 610 [Formula: see text]g/kg and bdl to 441 [Formula: see text]g/kg respectively. Thus, our study indicates the continuous occurrence and persistent nature of contaminants in the agricultural soil of Kasaragod. Therefore, periodic monitoring of soil contaminants is recommended in Kasaragod to assess its effect on the ecosystem and to develop an effective remediation strategy.

Electrochemical biosensor based on cellulose nanofibers/graphene oxide and acetylcholinesterase for the detection of chlorpyrifos pesticide in water and fruit juice†

In this work, cellulose nanofibers and graphene oxide are used to fabricate a simple and reliable electrochemical biosensor, based on acetylcholinesterase (AChE) for the detection of highly dangerous organophosphates (OPs), utilizing chlorpyrifos as a representative sample. AChE is an enzyme that is essential for neurotransmission and catalyzes the conversion of acetylcholine (ATCh) into thiocholine and acetic acid. The pesticide used in this work, chlorpyrifos, inhibits the catalytic activity of AChE on ATCh, and this inhibition can be measured using square wave voltammetry (SWV). Utilizing a process of surface modification, layers of cellulose nanofibers, graphene oxide, a chitosan-graphene oxide composite, and acetylcholinesterase (AChE/CS-GO/GO/CNFs) were immobilized on a screen-printed carbon electrode (SPCE). The modified SPCE working electrode was characterized using scanning electron microscopy and graphene oxide trapped in the cellulose nanofibers was found to increase the sensitivity of the biosensor. The modified biosensor demonstrated good performance for detection of chlorpyrifos over a linear range of 25–1000 nM under optimum conditions, and the limits of detection and quantification were 2.2 nM and 73 nM, respectively. Our sophisticated technique might offer a more precise, straightforward, quick, and environmentally friendly way to assess chlorpyrifos contamination in water and juice samples.

Cellulose nanofibers and graphene oxide are used to fabricate an electrochemical biosensor based on acetylcholinesterase for detecting organophosphates. This biosensor is simple and reliable, and it utilizes chlorpyrifos as a representative sample of highly dangerous OPs.

Recent advances in assessment methods and mechanism of microbe-mediated chlorpyrifos remediation

Chlorpyrifos (CP) is one of the Organophosphorus pesticides (OPs) primarily used in agriculture to safeguard crops from pests and diseases. The pervasive use of chlorpyrifos is hazardous to humans and the environment as it inhibits the receptor for acetylcholinesterase activity, leading to abnormalities linked to the central nervous system. Hence, there is an ardent need to develop an effective and sustainable approach to the on-site degradation of chlorpyrifos. The role of microbes in the remediation of pesticides is considered the most effective and eco-friendly approach, as they have strong degradative potential due to their gene and enzymes naturally adapted to these sites. Several reports have previously been published on exploring the role of microbes in the degradation of CP. However, detection of CP as an environmental contaminant is an essential prerequisite for developing an efficient microbial-mediated biodegradation method with less harmful intermediates. Most of the articles published to date discuss the fate and impact of CP in the environment along with its degradation mechanism but still fail to discuss the analytical portion. This review is focused on the latest developments in the field of bioremediation of CP along with its physicochemical properties, toxicity, fate, and conventional (UV-Visible spectrophotometer, FTIR, NMR, GC-MS, etc) and advanced detection methods (Biosensors and immunochromatography-based methods) from different environmental samples. Apart from it, this review explores the role of metagenomics, system biology, in-silico tools, and genetic engineering in facilitating the bioremediation of CP. One of the objectives of this review is to educate policymakers with scientific data that will enable the development of appropriate strategies to reduce pesticide exposure and the harmful health impacts on both Human and other environmental components. Moreover, this review provides up-to-date developments related to the sustainable remediation of CP.

Chlorpyrifos Occurrence and Toxicological Risk Assessment: A Review

Chlorpyrifos (CPF) was the most frequently used pesticide in food production in the European Union (EU) until 2020. Unfortunately, this compound is still being applied in other parts of the world. National monitoring of pesticides conducted in various countries indicates the presence of CPF in soil, food, and water, which may have toxic effects on consumers, farmers, and animal health. In addition, CPF may influence changes in the population of fungi, bacteria, and actinomycete in soil and can inhibit nitrogen mineralization. The mechanisms of CPF activity are based on the inhibition of acetylcholinesterase (AChE) activity. This compound also exhibits reproductive toxicity, neurotoxicity, and genotoxicity. The problem seems to be the discrepancy between the actual observations and the final conclusions drawn for the substance's approval in reports presenting the toxic impact of CPF on human health. Therefore, this influence is still a current and important issue that requires continuous monitoring despite its withdrawal from the market in the EU. This review traces the scientific reports describing the effects of CPF resulting in changes occurring in both the environment and at the cellular and tissue level in humans and animals. It also provides an insight into the hazards and risks to human health in food consumer products in which CPF has been detected.

Cognitive Impairment and Neurodegenerative Diseases Development Associated with Organophosphate Pesticides Exposure: a Review Study

A significant body of literature emphasizes the role of insecticide, particularly organophosphates (OPs), as the major environmental factor in the etiology of neurodegenerative diseases. This review aims to study the relationship between OP insecticide exposure, cognitive impairment, and neurodegenerative disease development. Human populations, especially in developing countries, are frequently exposed to OPs due to their extensive applications. The involvement of various signaling pathways in OP neurotoxicity are reported, but the OP-induced cognitive impairment and link between OP exposure and the pathophysiology of neurodegenerative diseases are not clearly understood. In the present review, we have therefore aimed to come to new conclusions which may help to find protective and preventive strategies against OP neurotoxicity and may establish a possible link between organophosphate exposure, cognitive impairment, and OP-induced neurotoxicity. Moreover, we discuss the findings obtained from animal and human research providing some support for OP-induced cognitive impairment and neurodegenerative disorders.

The effectiveness of vitamin C on quinalphos ileal toxicity: a study of histological, ultrastructural, and oxidative stress markers

There is a significant hazard of human exposure to the organophosphates which is a constant threat, and they are responsible for numerous cases of poisoning and mammalian toxicity annually in non-target wildlife. The antioxidants, including the vitamin C (Vit C), have a protective effect on some organophosphorus compounds-induced organ damage. Quinalphos (QP) is one of these compounds. The investigation's objective is to see if there was any effect of QP on the rat ileum which could be rectified by using Vit C. Three groups of 24 animals were created. As a control, the first group was given pure water. Second group subjected to oral gavages of QPs. Third group rats were given oral gavages of Vit C plus QPs for 10 days. The reaction of ileal enterocytes to food-borne QPs was marked by poorly organized microvilli, numerous vacuoles within them, disrupted nuclei with chromatin margination, disoriented mitochondria, and an expanded intercellular space. The absorptive columnar cell illustrated many vacuoles inside with herniation of microvilli, and normal goblet cells were also seen. Many Paneth cells towards the lumen of intestinal gland contained secretory granules of different sizes and shapes. The histological architecture of the ileal mucosa in the QP plus Vit C group was found to be close to those of healthy controls. The outcomes of this study suggest that administering Vit C in rats treated with QPs protects them from ill dysfunction caused by QP.

Conductive polymer layered semiconductor for degradation of triclopyr acid and 2,4-dichlorophenoxyacetic acid from aqueous stream using coalesce adsorption-photocatalysis technique

Polyaniline supported titanium dioxide nanoparticles (PTs) were fabricated using chemical oxidative aniline polymerization in the presence of titanium dioxide with ammonium peroxydisulfate as an oxidant. The synthesized PTs were thoroughly characterized for their morphological and functional features. PTs were employed for the photodegradation of acidic herbicides; 2,4-dichlorophenoxyacetic acid (2,4-D) and triclopyr acid (TCP). PT's surface modifications were imparted and their herbicide removal efficiencies were compared. The best operating conditions for adsorption/photocatalysis were 0.5 g/L photocatalyst, 10 mg/L concentration of individual herbicides resulted in 90.72% removal of TCP at pH 4 and 99.91% removal of 2,4-D at pH 5. Adsorption kinetics of herbicides, onto PT-1 showed the equilibrium attainment within 30 min and experimental data obeyed pseudo-second order model for TCP and 2,4-D removal which was governed by chemisorption. Analysis of TCP and 2,4-D adsorption indicated that the removal followed Sips model for TCP removal while Redlich-Peterson model explained the removal of 2,4-D by PT-1. Rate constants indicated that the amount of TiO₂ in the PTs played an important role in removing the herbicides and PT-1 material excellent remarkable activity for three cycles of photodegradation. Thus, this work reports the polymerization of aniline onto TiO₂ and their utility as photocatalyst for the expulsion of 2,4-D and TCP from water.

Uptake, translocation, and metabolism of anthracene in tea plants

The origin of 9, 10-anthraquinone (AQ) contamination in tea remains unclear at present. The objective of this study was to test the hypothesis that AQ could be produced from the precursor anthracene in tea plantations. To test this hypothesis, the uptake, translocation, and transformation of anthracene in tea (Camellia sinensis) seedlings using hydroponic experimentation was investigated. Anthracene concentrations in tea tissues rose with increased anthracene exposure, which in the roots were significantly (p < 0.05) higher than those in aboveground parts at the end of the exposure. These results indicated that anthracene tended to be adsorbed into tea seedling via the roots and accumulated largely within roots. The three main pathways of anthracene degradation in tea seedlings were suggested: oxygen was incorporated in the 9^th and 10^th positions of anthracene resulting in AQ (I) and anthrone (II), and naphthalene was formed by ring fission of anthracene via methylanthracene (III). The principal anthracene metabolites were AQ and anthrone. The concentrations of AQ, like anthrone, were markedly elevated in the roots than those in stems throughout the entire exposure period. Moreover, the translocation factors for anthracene and its primary metabolites AQ and anthrone from roots to stems were persistently lower than 0.1, demonstrating a poor translocation from roots to the aboveground regions. However, tea seedlings could take anthracene up from water and translocate it to the leaves. It was a possible risk for AQ contamination in tea leaves continuously exposed to anthracene for long periods of time because tea plants were perennial crops.

Microbial adaptation and impact into the pesticide's degradation

The imprudent use of agrochemicals to control agriculture and household pests is unsafe for the environment. Hence, to protect the environment and diversity of living organisms, the degradation of pesticides has received widespread attention. There are different physical, chemical, and biological methods used to remediate pesticides in contaminated sites. Compared to other methods, biological approaches and their associated techniques are more effective, less expensive and eco-friendly. Microbes secrete several enzymes that can attach pesticides, break down organic compounds, and then convert toxic substances into carbon and water. Thus, there is a lack of knowledge regarding the functional genes and genomic potential of microbial species for the removal of emerging pollutants. Here we address the knowledge gaps by highlighting systematic biology and their role in adaptation of microbial species from agricultural soils with a history of pesticide usage and profiling shifts in functional genes and microbial taxa abundance. Moreover, by co-metabolism, the microbial species fulfill their nutritional requirements and perform more efficiently than single microbial-free cells. But in an open environment, free cells of microbes are not much prominent in the degradation process due to environmental conditions, incompatibilities with mechanical equipment and difficulties associated with evenly distributing inoculum through the agroecosystem. This review highlights emerging techniques involving the removal of pesticides in a field-scale environment like immobilization, biobed, biocomposites, biochar, biofilms, and bioreactors. In these techniques, different microbial cells, enzymes, natural fibers, and strains are used for the effective biodegradation of xenobiotic pesticides.

A worldwide review of currently used pesticides' monitoring in agricultural soils

The adverse effects of pesticides on the agricultural ecosystem have been matter of concern in recent decades. However, attention has mostly been directed to highly persistent chemicals leading to underestimating currently used pesticides. In this review we present an overview of the studies on monitoring currently used pesticides in agricultural soils around the world published in the last 50 years. Furthermore, all data available in the articles has been integrated into one united data set. Finally, an overall meta-analysis on the prepared data set was performed. The result of the meta-analysis has been presented in this article. It was revealed that the occurrence of currently used pesticides in the soil of agricultural regions was alarming in many countries, establishing the need for long-term monitoring programs, especially in regions with intensive agricultural activities, in order to determine real-world currently used pesticides fate and accumulation in the soil.

Titanium dioxide based nanocomposites - Current trends and emerging strategies for the photocatalytic degradation of ruinous environmental pollutants

Many ruinous pollutants are omnipresent in the environment and among them; pesticides are xenobiotic and pose to be a bio-recalcitrance. Their detrimental ecological and environmental impacts attract attention of environmental excerpts and the surge of stringent regulations have endows the need of a technically feasible treatment. This critical review emphasizes about the occurrence, abundance and fate of structurally distinct pesticides in different environment. The practiced remedial strategies and in particular, the advanced oxidation processes (AOPs) those utilize the photo-catalytic properties of nano-composites for the degradation of pollutants are critically discussed. Photo-catalytic degradation utilizes many composite materials at nano-scale level, wherein synthesis of nano-composites with appropriate precursors and other adjoining functional moieties are of prime importance. Therefore, suitable starter materials along with the reaction conditions are prerequisite for effectively tailoring the nano-composites. The aforementioned aspects and their customized applications are critically discussed. The associated challenges, opportunities and process economics of degradation using photo-catalytic AOP techniques are highlighted and in addition, the review tries to explain how best the photo-degradation can be a stand-alone tool with a societal importance. Conclusively, the future prospects for undertaking new researches in photo-catalytic breakdown of pollutants that can be judiciously sustainable.

Chromatographic techniques for the analysis of organophosphate pesticides with their extraction approach: a review (2015-2020)

In agriculture, a wide range of OPPs has been employed to boost crop yield, quality, and storage life. However, due to the ever-increasing population and rapid urbanization, pesticide use has surged in recent years. These compounds are exceedingly poisonous to humans, and despite the fact that specific legislation prohibits their use, the frequency of toxic and/or fatal incidents, as well as current statistics, suggest that they are currently accessible. As a result, determining the exposure to these substances as well as their detection (and that of their metabolites) in different types of exposed samples has become a hot issue in terms of quality and safety concerns. However, developing tools for the evaluation of these substances is a critical challenge for laboratories. Various chromatographic-based methods reported in the period of 2015-2020 have been developed, which are summarized and critically reviewed in this article, including the extraction of the target OPPs from different kinds of matrices. A comparison among the extraction and analysis techniques has been made in the current review article.

Optimization of extraction conditions and determination of the Chlorpyrifos, Diazinon, and malathion residues in environment samples: Fruit (Apple, Orange, and Tomato)

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CPF, diazinon, and malathion residues in fruit was studed.

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Concentration of studied pesticides is positively correlated to the texture of studied fruits.

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Pesticide residues in studying fruits decreased by an increase in public surveillance.

Organophosphate (OP) insecticide, such as diazinon is found in the environments like water which is still approved for agricultural uses. When diazinon residues enter the human body, it functions as an acetylcholinesterase (AChE) inhibitor. This research aims to measure of chlorpyrifos (CPF), diazinon, and malathion residues in fruit such as apple, orange, and tomato after optimizing extraction conditions. Pesticide residues are measured by gas chromatography (GC) technique. Effective variables on pesticide residues are studied including pesticides kind, sampling station, and fruit kind. Results show that average concentration CPF, diazinon, and malathion residues in orange water are 7.05 ± 0.01 mg L⁻¹, 6.66 ± 0.03 mg L⁻¹, and 12.38 ± 0.02 µgL⁻¹, respectively. The average concentration CPF, diazinon, and malathion residues in apple water are 0.74 ± 0.02 mgL⁻¹, 0.70 ± 0.01 mgL⁻¹, and 1.10 ± 0.01 µgL⁻¹, respectively. The average concentration CPF, diazinon, and malathion residues in tomato water are 0.60 ± 0.02 mgL⁻¹, 0.57 ± 0.02 mgL⁻¹, and 0.89 ± 0.01 µgL⁻¹, respectively. The highest CPF concentration is observed in the orange fruit from station 20. Due to an appropriate storage condition and presenting organic fruits in the supermarket, the least mean concentration of pesticides is obtained in studied fruits from station 2. The manner of washing, peeling, and storage period before consuming fruits lead to decreasing studied pesticides concentration about 15–35, 40–50, and 50–60%, respectively. Increasing the fruit shelf-life led to decreasing studied pesticides concentration. Between pesticide concentration and variables: pesticides kind, sampling station, fruit kind, are not seen meaningful statistic relationship (P > 0.05). This study showed that pesticide residues in fruits can be decreased by washing, refrigerating, peeling procedures and increase in public surveillance.

Tapping the Role of Microbial Biosurfactants in Pesticide Remediation: An Eco-Friendly Approach for Environmental Sustainability

Pesticides are used indiscriminately all over the world to protect crops from pests and pathogens. If they are used in excess, they contaminate the soil and water bodies and negatively affect human health and the environment. However, bioremediation is the most viable option to deal with these pollutants, but it has certain limitations. Therefore, harnessing the role of microbial biosurfactants in pesticide remediation is a promising approach. Biosurfactants are the amphiphilic compounds that can help to increase the bioavailability of pesticides, and speeds up the bioremediation process. Biosurfactants lower the surface area and interfacial tension of immiscible fluids and boost the solubility and sorption of hydrophobic pesticide contaminants. They have the property of biodegradability, low toxicity, high selectivity, and broad action spectrum under extreme pH, temperature, and salinity conditions, as well as a low critical micelle concentration (CMC). All these factors can augment the process of pesticide remediation. Application of metagenomic and in-silico tools would help by rapidly characterizing pesticide degrading microorganisms at a taxonomic and functional level. A comprehensive review of the literature shows that the role of biosurfactants in the biological remediation of pesticides has received limited attention. Therefore, this article is intended to provide a detailed overview of the role of various biosurfactants in improving pesticide remediation as well as different methods used for the detection of microbial biosurfactants. Additionally, this article covers the role of advanced metagenomics tools in characterizing the biosurfactant producing pesticide degrading microbes from different environments.

Tyrosinase-mediated synthesis of larvicidal active 1,5-diphenyl pent-4-en-1-one derivatives against Culex quinquefasciatus and investigation of their ichthyotoxicity

1,5-diphenylpent-4-en-1-one derivatives were synthesised using the grindstone method with Cu(II)-tyrosinase used as a catalyst. This method showed a high yield under mild reaction conditions. The synthesised compounds were identified by FTIR, 1H NMR, 13C NMR, mass spectrometry, and elemental analysis. In this study, a total of 17 compounds (1a-1q) were synthesised, and their larvicidal and antifeedant activities were evaluated. Compound 1i (1-(5-oxo-1,5-diphenylpent-1-en-3-yl)-3-(3-phenylallylidene)thiourea) was notably more active (LD50: 28.5 µM) against Culex quinquefasciatus than permethrin(54.6 µM) and temephos(37.9 µM), whereas compound 1i at 100 µM caused 0% mortality in Oreochromis mossambicus within 24 h in an antifeedant screening, with ichthyotoxicity determined as the death ratio (%) at 24 h. Compounds 1a, 1e, 1f, 1j, and 1k were found to be highly toxic, whereas 1i was not toxic in antifeedant screening. Compound 1i was found to possess a high larvicidal activity against C. quinquefasciatus and was non-toxic to non-target aquatic species. Molecular docking studies also supported the finding that 1i is a potent larvicide with higher binding energy than the control (- 10.0 vs. - 7.6 kcal/mol) in the 3OGN protein. Lead molecules are important for their larvicidal properties and application as insecticides.

Enzyme inhibition methods based on Au nanomaterials for rapid detection of organophosphorus pesticides in agricultural and environmental samples: A review

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The review systematically and completely collated the enzyme inhibition method based on Au nanomaterials for organophosphorus pesticide detection method in the last 20 years.

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The significance of the optical properties of Au nanomaterials is outlined with different shapes, sizes, and surface modifiers in enzyme inhibition methods.

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The principles, classification and application of enzyme inhibition methods based on Au nanomaterials are comprehensively summarized from a new perspective in agricultural and environmental samples, including colorimetric method, fluorometric method, electrochemical biosensor method.

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Unlike traditional enzyme inhibition method, the merits of enzyme inhibition method based on Au nanomaterials were elaborated in this review.

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Combined with the research progress of enzyme inhibition method, this review predicts the future research direction of enzyme inhibition method, providing a theoretical reference for researchers.

Background

Organophosphorus pesticides (OPs), as insecticides or acaricides, are widely used in agricultural products to ensure agricultural production. However, widespread use of OPs leads to environmental contamination and significant negative consequences on biodiversity, food security, and water resources. Therefore, developing a sensitive and rapid method to determine OPs residues in different matrices is necessary. Originally, the enzyme inhibition methods are often used as preliminary screens of OPs in crops. Many studies on the characteristic of Au nanomaterials have constantly been emerging in the past decade. Combined with anisotropic Au nanomaterials, enzyme inhibition methods have the advantages of high sensitivity, durability, and high stability.

Aim of Review

This review aims to summarize the principles and strategies of gold (Au) nanomaterials in enzyme inhibition methods, including colorimetric (dispersion, particle size of Au nanomaterials) and fluorometric (fluorescence energy transfer, internal filtration effect) detection, and electrochemical sensing system (shape of Au nanomaterials, Au nanomaterials combined with other nanomaterials). The application of enzyme inhibition in agricultural products and research progress was also outlined. Next, this review illustrates the advantages of Au nanomaterial-based enzyme inhibition methods compared with conventional enzyme inhibition methods. The detection limits and linear range of colorimetric and fluorometric detection and electrochemical biosensors have also been provided. At last, key perspectives, trends, gaps, and future research directions are proposed.

Key Scientific Concepts of Review

Herein, we introduced the technology of enzyme inhibition method based on Au nanomaterials for onsite and infield rapid detection of organophosphorus pesticide.

Photocatalysis of dichlorvos using graphene oxide-TiO2nanocomposite under visible irradiation: process optimization using response surface methodology

Graphene oxide-TiO₂nanocomposite (GOT) was used for degradation and mineralization of dichlorvos, an organophosphorus pesticide, from aqueous solution under visible irradiation. The nanocomposite was characterized by scanning electron microscopy, transmission electron microscopy, UV-DRS, Fourier-transform infrared spectroscopy, Raman spectroscopy, and x-ray photoelectron spectroscopy. Anatase phase TiO₂nanoparticles (10-20 nm in diameter) were present in the nanocomposite. The nanoparticles were uniformly distributed on reduced GO sheets. A three-factor face-centered central composite design with response surface methodology was used for modeling and optimization of various variables that may potentially affect photodegradation, i.e. pH, catalyst loading, and initial dichlorvos concentration. A quadratic model was built to predict degradation, mineralization efficiency, and reaction rate constant. The experimental and predicted values depicted a good correlation and the utility of the models was confirmed by the highF-values observed for the degradation and mineralization models. High coefficient of determination (R²) was obtained for the degradation (R² = 0.95) and mineralization (R² = 0.93) models. Pareto analysis was carried out to determine the effect of each variable on photocatalytic degradation and mineralization. The predicted results suggested that the optimum conditions for obtaining maximum degradation (69%) and mineralization (64%) were: initial dichlorvos concentration of 0.5 mg l^-1with a catalyst dose of 110 mg l^-1at pH 6.5. The main effect plots also suggested a significant influence of the variables used in the photocatalysis of dichlorvos by GOT.

Assessment of Organophosphate Pesticides Exposure in Men with Idiopathic Abnormal Semen Analysis: A Cross-Sectional Pilot Study

Background:

Because of the widespread use of organophosphate (OP) pesticides in agriculture, they are major environmental contaminants in developing countries. OP pesticides decrease sperm concentration and affect its quality, viability, and motility. Studies have demonstrated the association between abnormal semen analysis and OP pesticides exposure among the high-risk population. As there is limited data on the percentage of OP pesticides exposure, the study aimed to determine the OP pesticides exposure in Southern Indian men with idiopathic abnormal semen analysis and find the possible source of their OP pesticides exposure.

Materials and Methods:

In this cross-sectional pilot study, fifty men with idiopathic abnormal semen analysis as cases and fifty men with normal semen analysis as controls were recruited. Detailed history was taken and general and systemic examinations were carried out. OP pesticides exposure was determined by assessment of pseudocholinesterase and acetylcholinesterase levels and urinary OP pesticides metabolites dialkyl phosphate (DAP) consisting of dimethyl phosphate (DMP), diethyl thiophosphate (DETP), and diethyl dithiophosphate (DEDTP).

Results:

Cases had statistically significantly lower levels of pseudocholinesterase (5792.07 ± 1969.89 vs. 10267.01 ± 3258.58 IU/L) (P=0.006) and acetylcholinesterase [102.90 (45.88-262.74) vs. 570.31 (200.24-975.30) IU/L] (P=0.001) as compared to controls. Cases had a statistically significantly higher percentage of urinary DAP positivity as compared to controls (80 vs. 38%, P<0.0001). Hence, cases had a significantly higher percentage of OP pesticides exposure as compared to controls (20 vs. 4%, P=0.015). OP-exposed cases had significantly higher urinary DETP and DEDTP levels as compared to OP non-exposed cases. Also, urinary DETP and DEDTP levels were significantly negatively associated with sperm concentration, motility, and normal morphology among OP-exposed cases.

Conclusion:

Southern Indian men with idiopathic abnormal semen analysis had a significantly higher percentage of OP pesticides exposure as compared to men with a normal semen analysis.

Sub-lethal effects of organophosphates and synthetic pyrethroid insecticides on muscle tissue transaminases of Oreochromis niloticus in vivo

Organophosphates and synthetic pyrethroid insecticides have been commonly used in public health and agriculture. The present study aimed to evaluate the sub-lethal effects of organophosphates and synthetic pyrethroid insecticides on transaminases: glutamate oxaloacetate/aspartate transaminase (AST) and glutamate pyruvate/alanine transaminase (ALT) in Oreochromis niloticus. Fish were exposed to malathion (OP), chlorpyrifos (OP) and λ-cyhalothrin (synthetic pyrethroid) at sub-lethal concentrations of 1.425, 0.125 and 0.0039 ppm, respectively for 24 and 48 h. AST and ALT activities were shown to be remarkably (p < 0.05) decreased and increased, respectively in O. niloticus treated with the insecticides. The highest and lowest inhibition in AST level were noted as -12.2% and -12.2% in chlorpyrifos and λ-cyhalothrin 24 h treated fish samples, respectively. The highest and lowest elevation in ALT level were recorded as + 313% and 237% in 48 h chlorpyrifos and 24 h malathion treated fish samples, respectively. This indicates that the insecticides used in this study did not result in death but in changes in AST and ALT enzyme activities. Therefore, organophosphates (malathion, chlorpyrifos) and synthetic pyrethroid (λ-cyhalothrin) insecticides are toxic to fishes and could affects their survival in their natural habitat.

Organophosphorus pesticide quinalphos (Ekalux 25 E.C.) reduces sperm functional competence and decreases the fertilisation potential in Swiss albino mice

Quinalphos (QP) is one of the most commonly used organophosphate pesticide for agriculture. In this study, adult Swiss albino male mice were orally administered with 0.25, 0.5 and 1.0 mg/kg of QP (Ekalux 25 E.C.) for ten consecutive days and the reproductive function was assessed at 35 and 70 days after QP treatment. At highest dose (1.0 mg/kg), QP exposure resulted in significant decrease in motility and increase in sperm head defects and DNA damage. Pharmacokinetic data showed a threefold increase in concentration of QP in the testis as compared to serum. QP was detectable in testes even after 24 hr of administration indicating slow clearance from tissue. In addition, high oestradiol, low testosterone level with a parallel increase in aromatase and cytochrome P450 transcript levels was observed. Significant decrease in fertilisation, lower blastocyst rate and poor blastocyst quality was observed when spermatozoa collected from QP exposed mice were subjected to in vitro fertilisation. In conclusion, exposure of QP to male mice decreases the sperm functional competence and fertilising ability, which appears to be mediated through elevated oxidative stress and altered steroidogenesis in testes.

Clinical utility of validated gas chromatography-ion trap mass spectrometry in patients with anticholinesterase pesticides poisoning

Intentional or unintentional intake of anticholinesterase pesticides became common due to their extensive use in agricultural and domestic purposes, resulting in numerous poisoning cases. A simple, accurate, and sensitive gas chromatography-ion trap mass spectrometry-based method for the quantification of 12 anticholinesterase pesticides (monocrotophos, dimethoate, dichlorvos, azinphos-methyl, carbofuran, chlorpyrifos, dialifos, diazinon, malathion, parathion, methidathion, and terbufos) in serum was developed, and its utility in patients with alleged pesticides poisoning was assessed. The quantification was performed using liquid-liquid extraction by toluene/chloroform (4:1,v/v) with 500 μL of serum. On column limit of detection and limit of quantification were less than 50.00 μg/L. The recovery ranged from 97.54 to 103.23%. The calibration curves were linear (R² > 0.9937). Accuracy was found to be between - 7.1 and 7.2%. Intra-day and inter-day reproducibility was less than 17% for the spiked quality control serum samples. The level of pesticide in serum quantified by the validated method correlated with clinical signs and symptoms, pseudo-cholinesterase activity, total atropine dose, length of hospital stay, and clinical outcome in 15 patients with alleged pesticide poisoning. The validated method may be used for monitoring and prognosis in patients with pesticide poisoning and diagnosis of poisoning in forensic toxicology.

Analysis of suppressive effects of pesticide triazophos on leucocyte immune responses in a teleost, Channa Punctatus

Triazophos is a commonly used organophosphate insecticide, which inhibits the acetylcholinesterase enzyme and causes paralysis and death of insects. Impact of the pesticides on immunity has scarcely been investigated, especially in fishes. The present study was designed to analyze the immunotoxic role of in vitro triazophos exposure to the leucocytes in freshwater teleost, Channa punctatus. Triazophos, at in vitro concentrations of 0.1, 0.5, and 1 µg ml^-1, was used to study leucocyte phagocytosis, superoxide production, nitrite release, and lymphocyte proliferation. Dose-dependent suppression of various immune responses was observed. Nitrite release and superoxide production by leucocytes were reduced in cultures incubated with triazophos. Mitogen-induced lymphocyte proliferation was significantly reduced at 0.5 and 1 µg ml^-1 but not at 0.1 µg ml^-1 concentration of pesticide. The biphasic suppressive effect was also discovered while evaluating phagocytic response. These investigations describe the effects of pesticide on immune responses in C. punctatus, which are helpful in understanding the immunotoxicity in fish. Substantially more researches are required to help design the measures to combat ecotoxicity in freshwater bodies.

Microfluidic Affinity Sensor Based on a Molecularly Imprinted Polymer for Ultrasensitive Detection of Chlorpyrifos

The persistent use of pesticides in the agriculture field remains a serious issue related to public health. In the present work, molecularly imprinted polymer thin films were developed using electropolymerization of pyrrole (py) onto gold microelectrodes followed by electrodeposition for the selective detection of chlorpyrifos (CPF). The molecularly imprinted polymer (MIP) was synthesized by the electrochemical deposition method, which allowed in-line transfer of MIP on gold microelectrodes without using any additional adhering agents. Various parameters such as pH, monomer ratio, scan rate, and deposition cycle were optimized for sensor fabrication. The sensor was characterized at every stage of fabrication using various spectroscopic, microscopic, and electrochemical techniques. The sensor requires only 2 μL of the analyte and its linear detection range was found to be 1 μM to 1 fM. The developed sensor's limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.93 and 2.82 fM, respectively, with a sensitivity of 3.98 (μA/(μM)/ mm². The sensor's shelf life was tested for 70 days. The applicability of the sensor in detecting CPF in fruit and vegetable samples was also assessed out with recovery % between 91 and 97% (RSD < 5%). The developed sensor possesses a huge commercial potential for on-field monitoring of pesticides.

Prevalence of Acute Pesticide Poisoning among Pesticide Applicators in Cardamom Plantations: A Cross-Sectional Study from Idukki District, Kerala

Background

Pesticide poisoning is a burning occupational health issue across the world. The pesticide use in the cardamom plantations of Idukki district, Kerala, India is one of the world's highest. However, limited studies addressed its ill effects on the health of pesticide applicators.

Aims

To assess the magnitude of acute pesticide poisoning (APP) among pesticide applicators and understand the nature of severity based on their occupational characteristics.

Settings and Design

A descriptive cross-sectional study was conducted in 2018. A total of 300 pesticide applicators with minimum 1-year experience (79.3% males) were selected from 30 randomly selected cardamom plantations in Udumbanchola Taluk.

Methods

WHO Field Surveys of Exposure to Pesticides Standard Protocol and Murphy's method of Farmer Self-Surveillance system of pesticide poisoning were used for assessing pesticide exposure and APP, respectively. Statistical analysis used: Descriptive (frequencies) and exploratory statistical analyses (Pearson's Chi-square test) were done using IBM SPSS 23.0.

Results

The prevalence of APP in this study was 100% as all the pesticide applicators reported at least one sign and/or symptom of APP. The mild APP was more prevalent (80.7%), followed by moderate (18.7) and severe (0.60). Decrease in duration and frequency of spraying, use of motor pump sprayer, safe storage and disposal of pesticides, and proper personal hygiene were found to reduce the severity of APP.

Conclusion

All the pesticide applicators in cardamom plantations of Idukki are at risk of APP. It is important to train them about the measures to prevent the same.

Organophosphorus Nerve Agents: Types, Toxicity, and Treatments

Organophosphorus compounds are extensively used worldwide as pesticides which cause great hazards to human health. Nerve agents, a subcategory of the organophosphorus compounds, have been produced and used during wars, and they have also been used in terrorist activities. These compounds possess physiological threats by interacting and inhibiting acetylcholinesterase enzyme which leads to the cholinergic crisis. After a general introduction, this review elucidates the mechanisms underlying cholinergic and noncholinergic effects of organophosphorus compounds. The conceivable treatment strategies for organophosphate poisoning are different types of bioscavengers which include stoichiometric, catalytic, and pseudocatalytic. The current research on the promising treatments specifically the catalytic bioscavengers including several wild-type organophosphate hydrolases such as paraoxonase and phosphotriesterase, phosphotriesterase-like lactonase, methyl parathion hydrolase, organophosphate acid anhydrolase, diisopropyl fluorophosphatase, human triphosphate nucleotidohydrolase, and senescence marker protein has been widely discussed. Organophosphorus compounds are reported to be the nonphysiological substrate for many mammalian organophosphate hydrolysing enzymes; therefore, the efficiency of these enzymes toward these compounds is inadequate. Hence, studies have been conducted to create mutants with an enhanced rate of hydrolysis and high specificity. Several mutants have been created by applying directed molecular evolution and/or targeted mutagenesis, and catalytic efficiency has been characterized. Generally, organophosphorus compounds are chiral in nature. The development of mutant enzymes for providing superior stereoselective degradation of toxic organophosphorus compounds has also been widely accounted for in this review. Existing enzymes have shown limited efficiency; hence, more effective treatment strategies have also been critically analyzed.

Review of pesticide residue analysis in fruits and vegetables. Pre-treatment, extraction and detection techniques

A wide variety of pesticides have been used in agriculture to increase the yield, quality and extend the storage life of crops. However, the use of pesticide has been increased now a day due to the ever-increasing population and rapid urbanization. The continuous uses of these pesticides have resulted in contamination of the environment, crops and also caused potential risk to human health. For this reason, strict regulations are developed and regulated to monitor these compounds. To date, several techniques have been developed for the extraction and detection of pesticides, from traditional to advanced detection techniques. The present study delineates a comprehensive up to date overview of the available traditional methods (gas chromatography and high-performance liquid chromatography coupled with various detector) to advanced pre-treatment (polystyrene-coated magnetic nanoparticle) and detection (sensor development and nanotechnology) techniques used in the analysis of pesticides residue in various fruits and vegetables. Also, categorization of pesticides and its toxicity have been discussed.

Enzyme-based optical biosensors for organophosphate class of pesticide detection

A systematic review of enzyme based optical detection schemes for the detection and analysis of organophosphate pesticides has been presented.

UIISScan 1.1: A Field portable high-throughput platform tool for biomedical and agricultural applications

The colorimetric sensing technology has evolved into an essential tool for high-throughput analysis including portability and cost-effectiveness among available biomedical and agricultural screening approach. In this endeavor, the objective of work is to focus on the development of a field-portable instrument based on an Uniform Illumination Imaging System (UIIS), which will facilitate the colorimetric biochemical sensing. The developed field-portable, wavelength independent UIIS has been exploited for (a) rotavirus detection using commercial enzymatic immunoassay based microplate kit; (b) pesticide residue detection and quantification; The proposed system exhibited a good correlation in comparison to another two conventional techniques, i.e., multi-plate reader (r = 0.9991938) and LC-MS/MS (r = 0.998877399) with a short analysis time of 5 min for 95 test samples. Moreover, the feasibility of UIIS system has also been explored as field-portable enzyme-linked immunosorbent assay (ELISA) plate reader. By incorporating the Mahalanobis distance calculation, the advanced algorithm has been investigated and developed to analyze the data. The overall dataset was transformed into a matrix format to give a good correlation with a conventional plate reader, i.e., r = 0.915389612. Internet of things (IoT) enabled decision support system can be exploited by using big data analytics. Finally, test results can be shared with concerned stakeholders and the remote users. Thus, the developed UIIS will help to identify potential public health threats expeditiosly compared to conventional time consuming process of sample submission to the laboratory for analysis.

Pollution status and bioremediation of chlorpyrifos in environmental matrices by the application of bacterial communities: A review

Pesticides currently play a significant role in enhancing agricultural production and offer economic assistance to our farmers. However, their indiscriminate and injudicious application has caused environmental problems and public health concerns. Chlorpyrifos, a pesticide of organophosphate category is used globally as an insecticide, acaricide, and termiticide in households, public health, and agriculture against pests of a wide range. The extensive application of chlorpyrifos has caused contamination of various ecosystems like soil, sediments, water, air and also leads to the disruption of biogeochemical cycles. Moreover, chlorpyrifos residues have been detected in sediments, soil, water, vegetables, foodstuff and even in human fluids. It has been confirmed that exposure to chlorpyrifos has created health complications due to the inhibition of choline esterase enzyme, which leads to neurotoxicity, immunological and psychological effects in humans plus to the natural ecosystem. Due to the higher toxicity of chlorpyrifos, research is conducted globally to design and develop effective and efficient approaches for the elimination of chlorpyrifos and its associated compounds from environmental settings. At present different techniques are available for detoxification of such pesticides, but the microbial degradation of chlorpyrifos especially by bacteria has proven to be highly efficient, economical and environmental friendly. Thus, this paper aims to provide an outline of research events on this issue and summarize the evidences of chlorpyrifos pollution, discuss the analytical summary of latest research results on bacterial degradation of chlorpyrifos and possible degradation pathways along with effects on its degradation by different environmental parameters.

Pesticide residues in Indian raw honeys, an indicator of environmental pollution

Honey has multifaceted beneficial properties, but polluted environment and unapproved apicultural practices have led to its contamination. In this study, QuEChERS method followed by chromatographic analysis by GC-μECD/FTD and GC-MS was validated and used for determination of 24 pesticides in 100 raw honey samples from various floral origins of Northern India. Matrix-matched calibrations showed that the method was selective and linear (r² > 0.99) with detection limit < 9.1 ng g^-1 for all the studied pesticides except for monocrotophos (21.3 ng g^-1). The average recoveries at different fortification levels ranged from 86.0 to 107.7% with relative standard deviation < 20%. Pesticide residues were detected in 19.0% samples, and most prevalent compounds detected were dichlorvos in 6.0% samples followed by monocrotophos (5.0%), profenofos (5.0%), permethrin (4.0%), ethion (3.0%), and lindane (3.0%) with concentrations ranging from 58.8 to 225.5, from 96.0 to 430.1, from 14.6 to 43.2, from 27.8 to 39.6, from 25.6 to 28.0, and from 19.6 to 99.2 ng g^-1, respectively. Honey samples originating from cotton, sunflower, and mustard crops (33.3%) that tested positive for pesticide residues were found to be significantly higher (p < 0.05) than the honey originating from natural and fruity vegetation (13.5%). Therefore, considering the contamination of environmental compartments due to extensive application of pesticides in the study area and their potential for subsequent transfer to honey by the expeditious bees, the results of present study proclaim that honey may be used as an indicator of environmental pollution. Further, estimated daily intakes of all contaminants were found to be at levels well below their acceptable daily intakes suggesting that consumption of honeys at current levels does not pose deleterious effects on human health. However, precautionary measures should always be taken considering the customary honey feeding in infants and cumulative effect of these chemicals in the foreseeable future.

Joint toxic effects of triazophos and imidacloprid on zebrafish (Danio rerio)

Pesticide contamination is more often found as a mixture of different pesticides in water bodies rather than individual compounds. However, regulatory risk evaluation is mostly based on the effects of individual pesticides. In the present study, we aimed to investigate the individual and joint toxicities of triazophos (TRI) and imidacloprid (IMI) to the zebrafish (Danio rerio) using acute indices and various sublethal endpoints. Results from 96-h semi-static test indicated that the LC₅₀ values of TRI to D. rerio at multiple life stages (embryonic, larval, juvenile and adult stages) ranged from 0.49 (0.36-0.71) to 4.99 (2.06-6.81) mg a.i. L^-1, which were higher than those of IMI ranging from 26.39 (19.04-38.01) to 128.9 (68.47-173.6) mg a.i. L^-1. Pesticide mixtures of TRI and IMI displayed synergistic response to zebrafish embryos. Activities of carboxylesterase (CarE) and catalase (CAT) were significantly changed in most of the individual and joint exposures of pesticides compared with the control group. The expressions of 26 genes related to oxidative stress, cellular apoptosis, immune system, hypothalamic-pituitary-thyroid and hypothalamic-pituitary-gonadal axis at the mRNA level revealed that zebrafish embryos were affected by the individual or joint pesticides, and greater changes in the expressions of six genes (Mn-sod, CXCL-CIC, Dio1, Dio2, tsh and vtg1) were observed when exposed to joint pesticides compared with their individual pesticides. Taken together, the synergistic effects indicated that it was highly important to incorporate joint toxicity studies, especially at low concentrations, when assessing the risk of pesticides.