China
Africa
Explore chapters and articles related to this topic
List of Chemical Substances
Published in T.S.S. Dikshith, and Safety, 2016
Chlorpyrifos belongs to the class of insecticides known as organophosphates. Technical chlorpyrifos is an amber to white crystalline solid with a mild sulfur odor. It is insoluble in water, but soluble in benzene, acetone, chloroform, carbon disulfide, diethyl ether, xylene, methylene chloride, and methanol. Formulations of chlorpyrifos include emulsifiable concentrate, dust, granular wettable powder, microcapsule, pellet, and sprays. Chlorpyrifos is widely used as an active ingredient in many commercial insecticides, such as Dursban and Lorsban, to control household pests, mosquitoes, and pests. Formulations of chlorpy-rifos include emulsifiable concentrates, granules, wettable powders, dust, microcapsules, pellets, and sprays. The US EPA has classified chlorpyrifos as a GUP.
Role of Enzymes in the Bioremediation of Refractory Pollutants
Published in Maulin P. Shah, Removal of Refractory Pollutants from Wastewater Treatment Plants, 2021
Viresh R. Thamke, Ashvini U. Chaudhari, Kisan M. Kodam, Jyoti P. Jadhav
Hydrolases, belonging to the third category of the enzyme classification system, carry out the hydrolysis of several functional groups like esters, peptide bonds, carbon halides, urea, thioesters, and organophosphates that form the major constituents of pesticides. They bring about hydrolysis in the absence of redox cofactors and tolerate water miscible solvents, thus making them ideal candidates for in-situ bioremediation studies (Scott et al. 2008). Some of the enzymes included in this class are organophosphohydrolases (OPH) that carry out the detoxification of various organophosphorus insecticides like malathion, pyrethroid chlorpyrifos, and parathion. Chlorpyrifos is an effective insecticide used against a wide range of pests. It is readily soluble in organic solvents and is moderately toxic in nature. The chemical hydrolysis of chlorpyrifos results in the formation of 3,5,6-trichloro-2-pyridinol (TCP) as the major degradation product which is more toxic. It is observed that the degraded product TCP has anti-microbial properties, thus preventing the proliferation of chlorpyrifos-degrading bacteria in soil (Racke et al. 1990). Chlorpyrifos degradation is mainly related to the soil pH and mediated by soil microorganisms through non-specific and non-inducible enzyme systems; hence, chlorpyrifos is co-metabolically hydrolysed to TCP (Das and Chandran 2011). Very few reports indicate the microbial metabolism of TCP. Stanlake and Finn (1982) isolated Pseudomonas that could degrade TCP in a liquid medium using a reductive chlorination pathway. Several fungal species have been shown to utilize chlorpyrifos as their chief phosphorous and carbon source.
Trace Organics
Published in Robert H. Kadlec, Treatment Marshes for Runoff and Polishing, 2019
Common pesticides have been the focus of multiple wetland studies (Table 14.6). Loss rate coefficients vary considerably from study to study, but the corresponding half-lives are measured in days. Brief descriptions of these are as follows (see also Figure 14.1): Atrazine, a triazine herbicide, is used to prevent pre- and post-emergence broadleaf weeds in crops such as maize (corn) and sugarcane and on turf, such as golf courses and residential lawns. It is one of the most widely used herbicides in US and Australian agriculture. It was banned in the European Union in 2003. In the United States as of 2014, atrazine was the second-most widely used herbicide after glyphosate. Studies suggest that atrazine is an endocrine disruptor.Diazinon is an insecticide that belongs to a group of chemicals known as organophosphates. Diazinon is used in agriculture to control insects on fruit, vegetable, nut and field crops. Diazinon was used extensively in the United States starting in the 1950s. Before the cancellation of residential uses in 2004, diazinon was used for household insects, lawn and garden insect control, and to control insects on pets. It is banned in the European Union.Chlorpyrifos is an organophosphate insecticide used to control many different kinds of pests, including termites, mosquitoes, and roundworms. Chlorpyrifos is very toxic to many bird species such as grackles and pigeons. Chlorpyrifos is also very toxic to fish and aquatic invertebrates. Chlorpyrifos is very toxic to bees.Permethrin is a pyrethroid insecticide in the family. It is used in a number of ways to control insects. Products containing permethrin may be used in public health mosquito control programs. They may be used on food and feed crops, on ornamental lawns, on livestock and pets, in structures and buildings, and on clothing. Permethrin may also be used in places where food is handled, such as restaurants.
Biodegradation kinetics of dichlorvos and chlorpyrifos by enriched bacterial cultures from an agricultural soil
Published in Bioremediation Journal, 2019
Omkar Gaonkar, Indumathi M. Nambi, Govindarajan Suresh Kumar
Dichlorvos (0,0-dimethyl-2,2-dichlorovinyl phosphate; C4H7Cl2PO4) and chlorpyrifos [0,0-diethyl 0-(3,5,6-trichloro-2-pyridyl; C9H11Cl3NO3PS) phosphorothioate] are commonly used OPs in India. Dichlorvos which is relatively less toxic, has wide applications in lawns, gardens and for killing insects at homes (Golash and Gogate 2012). As it is highly water soluble, it can rapidly move through runoff to surface waters and infiltrate the soil to reach shallow groundwaters, thus causing damage to the environment (Calamari and Zhang 2002; Zulin et al. 2002). Chlorpyrifos is extensively used to prevent attack of insects and pests on economically important crops such as fruits, tea, coffee, vegetables, rice, wheat, etc. (Thengodkar and Sivakami 2010). A persistent usage of these pesticides can lead to contamination of the surface waters and groundwaters that can be toxic to humans, animals as well as birds. Acetyl-cholinesterase and cholinesterase enzymes are necessary for the efficient functioning of neuron and other processes. OPs inhibit the activities of these enzymes, thus adversely affecting the human nervous system (Bai et al. 2009).
Study of formation of valuable organic products from bioremediation of chlorpyrifos by bacteria catalyzed by molybdenum and zinc salt
Published in Bioremediation Journal, 2019
Sangita Saha, Achintya Mondal, Tanusri Mandal
Chlorpyrifos is highly toxic in nature and remains in environment for longer period of time as only 0.1% is utilized with respect to applied amount and rest remains in the environment (Yadav et al. 2015). It has also been reported that its effects have been found 24 km away from its applied-fields (Bootharaju and Pradeep 2012). Chlorpyrifos inhibits cholinesterase activity, which is the main component of nervous system for both human and insects (Xu et al. 2008). Hence, its contamination is a public-health concern as human-body may get affected through dermal, oral, or respiratory exposure resulting in cardiovascular system collapse, liver toxicity, and blockage of nervous system (Bootharaju and Pradeep 2012; Harishankar et al. 2013).
Toxicological and biochemical studies for chlorpyrifos insecticide on some mosquito larvae and their associated predators
Published in Egyptian Journal of Basic and Applied Sciences, 2022
Shaimaa H. Mohammed, Randa I. Eltaly, Hend H. Salem
Chlorpyrifos is an organophosphorus insecticide, which inhibiting the breakdown of acetylcholine. When insects are exposed, chlorpyrifos interacts to the active site of the AChE, which inhibiting breakdown of acetylcholine in the synapse [40]. Elevation of AChE in resistant insects results in a decreased sensitivity [41].