Mechanistic Approach for the Chemical and Bio-Chemical Aspects of Organophosphate Pesticides (original) (raw)
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Organophosphate Pesticide: Environmental impact and toxicity to organisms
International journal of research in agronomy, 2024
Organophosphates are one of the major constituent of herbicides, pesticides, insecticides and nerve gas. Azinophos-methyl, chlorpyrifos, diazinon, fonofos and disulfoton are well-known organophosphate pesticides (OPs) having extensive applications in agriculture, horticulture, pest control, plastic making, flame retardants and for several household applications. OPs are the ester forms of phosphoric acid, usually considered as safe for agriculture use due to their relatively fast degradation rates. Acute or chronic exposure to OPs can produce varying levels of toxicity in humans, animals, plants, and insects. These are known to inhibit acetylcholinesterase activity, not only in insects but also in aquatic and terrestrial organisms leading to respiratory, reproductive, nervous, hepatic and renal abnormalities. OPs disrupt the growth promoting mechanism by inhibiting various enzymes, transcuticular diffusion and permeability which is essential for the growth of plants. Regular use of OPs subside the microbial community and reduces soil fertility. Due to environmental concerns associated with the accumulation of OPs in food products and water supplies, there is an urgent need to develop rapid, reliable and economical method amenable to onsite applications. Here, we review different classes of organophosphate pesticides, their environmental issues, analytical techniques for estimation, and eco-friendly biodegradation approaches for its efficient bioremediation.
Scientific Reports
Toxicity of organophosphorus compounds (OPs) remains a major public health concern due to their widespread use as pesticides and the existence of nerve agents. Their common mechanism of action involves inhibition of enzymes acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) which are crucial for neurotransmission. Both chronic and acute poisoning by OPs can leave long-lasting health effects even when the patients are treated with standard medical therapy. Therefore, an increasing urgency exists to find more effective oxime reactivators for compounds which are resistant to reactivation, especially phosphoramidates. Here, we investigated in silico and in vitro interactions and kinetics of inhibition for human cholinesterases with four organophosphate pesticides—ethoprophos, fenamiphos, methamidophos and phosalone. Overall, ethoprophos and fenamiphos displayed higher potency as inhibitors for tested cholinesterases. Our results show that methamidophos-inhibited hAChE was more...
Toxic Effects of Organophosphates Pesticides. A Review
2020
Organophosphate pesticides (also known OPPs) have for many years been the choice candidate globally for pest control. OPPs have for over 80 years, been used in gardens, fields and greenhouses as crop protection agents, and even in homes as insecticides and mosquito abatement. Thus, year after year and with the repeated application of organophosphate agents, many problems have appeared as a result of excessive use of pesticides. The adverse effects of pesticides are well documented in human health, environment, pesticide residue in crops, soil and water contaminated by these pesticides. Therefore, it is necessary to shed more light on the risks associated with the irresponsible usage of organophosphate pesticides.
Toxicological Effects of Organophosphates Pesticides
For many years organophosphate pesticides considered the main option for a lot of people in many countries to manage different pests. It's more than 70 years now and OPs still use with certain purposes in gardens, fields and greenhouses as crop protection agents, or even at houses as public health agents. Thus, year after year and with the repeating usage of organophosphate agents many problems were appeared as a result to excessive use of pesticides. The adverse effects of pesticides usage represented in the effects on human health, environment, pesticides residue in crops and soil & water contaminated by these pesticides. Therefore, it was necessary to throw a light on the risks that generated by irresponsible usage of organophosphate pesticides.
isara solutions, 2021
Pesticides have been used in the field of agriculture ever since their role in the protection of crops from pests and increase in the productivity of the agricultural crop. In the agriculture sector, organophosphate pesticides are one of the most widely used insecticides; in fact, this group accounts for around 40% of all pesticides produced and used commercially. When these pesticides are ingested by a life form, their principal toxicological effect is the irreversible inhibition of the acetylcholinesterase (AChE) enzyme, which is essential for neurotransmission of signals and, as a result, impairs the respiratory system and neuromuscular transmission. All living strata exposed to these chemicals in different ways are at risk because the residues of these highly toxic chemicals have found their way into the underground water system through leakage into the ground, in rivers where agricultural runoff water is disposed of, and in the air when crops are sprayed. Acute neurological problems are among the health hazards associated with these chemicals. A sustainable approach and proper management should be adopted for the use of pesticides. One such is Integrated nutrient management (INM) which involves the use of organic, inorganic, manures, compost, etc. in the agricultural soil. It will not only helpful for the soil and crop quality but it will boost the agriculture sector.
Common Mechanism of Toxicity: A Case Study of Organophosphorus Pesticides
Toxicological Sciences, 1998
spectrum of cholinergic effects. An approach similar to that developed for OP pesticides could be used to determine if other classes or groups of pesticides that share structural and toxicological characteristics act by a common mechanism of toxicity or by distinct mechanisms,
Microbial Degradation of Organophosphorus Pesticides
Bioremediation and Phytoremediation Technologies in Sustainable Soil Management
Pesticide application increases crop yield by controlling, repelling, or destroying pests; but their excessive use cause harmful effects to various life forms including humans. When applied in large amounts, the agricultural pesticides move longer distances and can reach the water table at observable concentration. Consequently, pesticides can contaminate the areas which are far away from the sites where they were used actually. Among different groups of pesticides, organophosphorus pesticides (OPs) are applied globally and constitute the crucial and most commonly applied group which accounts for almost 36% of the entire world market. Methyl parathion (MP) is one of the most commonly used OPs. It has been recorded across the world that excessive use of OPs leads to the contamination of soil and water bodies and exposure to OPs causes disastrous effects to human health, various life forms and ecosystems. Thus, decontaminating pesticide contaminated area is a costly affair. Microorganisms play an important role in biodegradation of pesticides due to their adaptive nature to the environment that is contaminated. Mostly, organophosphorus compounds (OPCs) are completely mineralized by the microorganisms. Microorganisms degrade most of the OPCs as carbon or phosphorus source. From microbes, different enzymes have been isolated for studying and understanding the pathways involved in the biodegradation of OPs. 6.1 INTRODUCTION Pesticides are toxic chemical substances which are applied to control, repel, destroy, prevent, or mitigate any pest, i.e., insects, nematodes, mites, weeds, Apple Academic Press Author Copy Non Commercial Use 160 Bioremediation and Phytoremediation Technologies in Sustainable Soil Management, Volume 4 rats, etc.; hence beneficial for agricultural productivity [102]. On an average, 35% of potential crop productivity is destroyed all over the world to pre harvest pests [118]. Besides these, losses of food chain are also comparatively huge [68]. The world population is projected to rise in 2050 by 30% to nearly 9.2 billion. Therefore, agriculture has to meet an increasing demand for biofuel, food, fiber, feed, and other bio-based commodities [102]. Depletion of yield because of pests, weeds, and pathogens are main challenges to agricultural production worldwide [119]. Among crops, the potential damage caused by the pests ranges from almost 50% in wheat yield to over 80% in production of cotton at global level. Studies found 26-29% loss for cotton, soybean, and wheat and 40%, 37% and 31% for potatoes, rice, and maize, respectively [76]. In United States only, around 9.2 billion USD (United State Dollar) are invested on pesticides annually for improving crop production [102]. The 15-20 fold rises in the quantity of globally applied pesticides significantly improved the crop protection [118]. However, their excessive use results in the contamination of environment [15]. The pesticides are classed into four main groups namely organochlorine (OC), organophosphate (OP), carbamate, and pyrethroid pesticides. One of the important groups of pesticides which are used broadly are OPs viz. methyl parathion (MP), diazonin, malathion, chlorpyrifos (CPS), dimethoate, endosulfan, profenofos, monocrotophos [151], fenithrothion, fenamiphos (FEN) [154], dicrotophos, and coumaphos (Table 6.1). The OPs are primarily used to protect crops from pests, but their unused portion along with their derivatives remain as contaminants in soils, which in turn leads to acidification of soil, fertility loss, improved weed species resistance, nitrate leaching and biodiversity loss [111, 165, 170]. OPs are neurotoxicants which act on acetylcholinesterase (AChE) and inactivate AChE in both central and peripheral nervous system, as a result of which acetate and choline are formed [45]. Additionally, nerves are considerably over stimulated and blocked in mammals and insects. This suppression results in convulsion, paralysis, and finally death [154]. OPs also possess the proficiency for causing genotoxic and carcinogenic effect [82]. TABLE 6.1 Some Important OPs Along with Their Chemical Name Example Type Soil Half-Life (Days) Methyl parathion Insecticide 3-30
Water Research, 2005
Organophosphorus pesticides (OPs) are commonly detected in agricultural products, animal-derived foodstuffs, and environmental samples. Until now, the focus of research has been to evaluate the adverse effect of a single OP. While each OP may be present at concentrations under recognized as ''no observed adverse effect level (NOAEL)'', the combined effects of multiple OPs present at these low concentrations have not been sufficiently studied. Therefore, we developed an in vitro testing method to evaluate the toxicity of multiple OPs based on the degree of inhibition of cholinesterase (ChE) activity. This method requires only 10 min to complete and no specialized technology. We examined 15 OPs by this method and categorized them into three groups according to the degree of ChE inhibition. A relationship between the OPs' chemical structures and the degree of ChE inhibition emerged with the moiety-P-O-CQN-showing the strongest action. The degree of ChE inhibition increased with multiple OPs, and the degree of inhibition seemed to be additive. These results demonstrate that the combined toxicity of multiple OPs present in food or environmental samples is an easily determined and toxicologically relevant measure of overall toxicity of complex OPs mixtures. It is possible to apply this testing method as a monitoring technique in water quality management in order to control OPs. As a result, this method can play the role for the potential risk reduction to the ecosystem and may contribute to the preservation of the environment.
Spectroscopic Methods for the Detection of Organophosphate Pesticides – A Preview
Current World Environment Journal, 2013
Organophosphate pesticides (OPs) are the ester forms of phosphoric acid usually considered as secure for agriculture uses due to their relatively fast degradation rates. 1 Although the degradation of OPs is a linear function of microbial composition, pH, temperature, structural arrangement etc. OPs inhibit acetylcholinesterase (AChE) activity not only in insects only, but can also affect the nervous system of other organisms as well as humans. 1-3 Literature data illustrated the OPs persistence in soils years after their application. 4 But the reason behind this environmental persistence is not very clear. Pesticides has been transferred to humans through the food chain 4,7-9 and number of environmental 4-6 and health 10-14