Cholinesterase Status of Some Ethiopian State Farm Workers Exposed to Organophosphate Pesticides

Lakew, Kibruyisfa; Mekonnen, Yalemtsehay

doi:10.1539/joh.40.83

Cited by 5 publications

(5 citation statements)

References 14 publications

(3 reference statements)

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“…2003) to ward off mosquitoes and other domestic insects though it is difficult to know their contribution in the development of resistance. The contribution of pesticides used in agriculture to the development of resistance in the vector population cannot be overlooked as there are reports that DDT and different organophosphates (Abate 1996; Lakew & Mekonnen 1998; Amera & Abate 2008) and possibly pyrethroids are used to control agricultural pests.…”

Section: Discussionmentioning

confidence: 99%

Susceptibility of Anopheles gambiae s.l. to DDT, malathion, permethrin and deltamethrin in Ethiopia

Abate¹,

Hadis²

2011

Tropical Med Int Health

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Summaryobjective To assess the susceptibility ⁄ resistance level of Anopheles gambiae s.l. to DDT, malathion, permethrin and deltamethrin in different parts of Ethiopia.methods Field collected female An.gambiae s.l. was exposed for 1 h to discriminating dosage of 4% DDT, 5% malathion, 0.75% permethrin and 0.05% deltamethrin using WHO insecticide susceptibility test kits and procedures. Knockdown and mortality rates were recorded at 10, 15, 20, 30, 40, 50 and 60 min and 24 h post-exposure respectively.results Anopheles gambiae s.l. was sensitive to DDT only in 2 of 16 localities where susceptibility studies were carried out in northern Ethiopia; it was resistant in 11 sites and potentially resistant in three. To malathion, the test population was sensitive in four of the six study sites in southern Ethiopia and potentially resistant in the other two sites. In northern Ethiopia, the population was resistant in five localities and sensitive in three. Of the six localities in northern Ethiopia where permethrin was tested, populations were sensitive in three, resistant in one and potentially resistant in two. In southern Ethiopia, the populations were resistant in five of the six sites. Against deltamethrin, the population was sensitive in five of 13 localities, three in northern and two in southern Ethiopia. It was resistant only in two localities, one in northern and one in southern Ethiopia, and potentially resistant in five localities. In eastern Ethiopia at Sabure, the population was sensitive to all insecticides but DDT to which it was potentially resistant. conclusion The existence of high level of DDT and pyrethroid resistance with the possibility of crossresistance to each other and other classes of agricultural pesticides could seriously jeopardise the efficacy of both ITNs and IRS in the country in the future. Insecticide resistance monitoring and surveillance systems as part of a malaria control programme are mandatory for proper management of resistance. The use of a mixture of unrelated insecticides for impregnating nets and rotational use of insecticides for IRS is suggested as a way forward.

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Section: Discussionmentioning

confidence: 99%

Susceptibility of Anopheles gambiae s.l. to DDT, malathion, permethrin and deltamethrin in Ethiopia

Abate¹,

Hadis²

2011

Tropical Med Int Health

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“…22) Other investigators also studied ChE activities among pest-control workers who used chlorpyrifos occupationally, and the result showed that mean PChE and AChE activities after pesticide exposure were significantly lower than pre-exposure values (pϽ0.05); 16 and 40% of the pestcontrol workers had PChE and AChE levels below 50% of the pre-exposure values, respectively. 23) We propose that farm-worker exposure to OPs, such as chlorpyrifos, may be monitored by measuring the activity of plasma cholinesterase (PChE), but not AChE. Therefore, from a biological point of view, it may be used as a potential biomarker in monitoring pesticide exposure in the field.…”

Section: Discussionmentioning

confidence: 99%

Spectrophotometric Determination of Plasma and Red Blood Cell Cholinesterase Activity of 53 Fruit Farm Workers Pre- and Post-Exposed Chlorpyrifos for One Fruit Crop

Thetkathuek

Keifer²,

Fungladda

et al. 2005

CHEMICAL & PHARMACEUTICAL BULLETIN

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Chlorpyrifos (O,O-diethyl 0-(3,5,6-trichloro-2-pyridyl) phosphorothioate) belongs to the organophosphate insecticide (OPs) family, and is widely used to kill aphids in fruit farms. The demand for this insecticide is increasing. To our knowledge, there is no biological monitoring data for fruitfarm worker exposure to chlorpyrifos insecticide is available in Thailand. Biological monitoring is an essential component of any comprehensive assessment of exposure. In fact, these farm workers were at high risk of direct exposure to pesticides while mixing, loading, or spraying pesticide. [1][2][3][4] It has been reported that chlorpyrifos insecticide is rapidly absorbed by skin contact and/or oral administration, metabolized and excreted by mammals.5) The primary mechanism of action of organophosphorus (OP) insecticides like chlorpyrifos involves the inhibition of acetylcholinesterase (AChE), resulting in a wide range of neurotoxic effects in humans, such as sensory and motor neuropathy with permanent paralysis. The inhibition of cholinesterase enzyme (ChE) may cause acetylcholine accumulation at the synaptic cleft, causing the stimulation of autonomic receptors and depolarizing blocks of neuromuscular junction receptors in the human body. In addition, it was proposed that both long-term exposure to subclinical doses of OP, and after acute intoxication, could be responsible for chronic OP-induced neuropsychiatric disorders. [6][7][8][9] ChE can be used as an index of cholinergic function and changes in enzyme activity may indicate alterations in the availability of acetylcholine at the receptor level. [10][11][12][13][14] In vivo, ChE activity reflecting the functional quantities of the enzyme can be assessed using blood, plasma, and red blood cells. Inhibition of ChE leads to a down-regulation of cholinergic receptors. The levels of ChE appear to be controlled by the interaction of acetylcholine with its receptors, with enhanced interaction increasing the levels of ChE. 15)This study aims to investigate any changes in ChE activity reflecting the cholinergic function of fruit farm workers exposed to the neurotoxin, chlorpyrifos insecticide, during one fruit crop. For this purpose, the blood ChE activities of 53 farm workers on fruit farms in Rayong Province, Thailand, were collected and analyzed.In the present study, a significant decrease in plasma (PChE), but not red blood cell ChE (AChE) activity after exposure to chlorpyrifos in the spraying season, compared with the non-spraying season, was found. The results suggest an interaction between chlorpyrifos and monoaminergic-cholinergic neurotransmission that leads to a decrease in the functional enzyme available to degrade acetylcholine. We propose that PChE activity can be used as a biomarker for monitoring early toxicity induced by chlorpyrifos insecticide. Determination of baseline red blood cell and plasma cholinesterase activity among applicators in the non-spraying season is very important, before identifying the effects of these pesticide exposures. Experiment...

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“…Farm workers are at risk of exposure to pesticides during mixing, loading and spraying of pesticides and during the assessment of pests [1,2]. Organophosphate and carbamate pesticides inhibit the action of acetyl cholinesterase, the enzyme used to deactivate the nerve transmitter acetylcholine at the nerve endings.…”

Section: Introductionmentioning

confidence: 99%

Plasma cholinesterase level of Ethiopian farm workers exposed to chemical pesticide

Mekonnen¹,

Ejigu²

2005

Occupational Medicine

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Cholinesterase Status of Some Ethiopian State Farm Workers Exposed to Organophosphate Pesticides

Cited by 5 publications

References 14 publications

Susceptibility of Anopheles gambiae s.l. to DDT, malathion, permethrin and deltamethrin in Ethiopia

Susceptibility of Anopheles gambiae s.l. to DDT, malathion, permethrin and deltamethrin in Ethiopia

Spectrophotometric Determination of Plasma and Red Blood Cell Cholinesterase Activity of 53 Fruit Farm Workers Pre- and Post-Exposed Chlorpyrifos for One Fruit Crop

Plasma cholinesterase level of Ethiopian farm workers exposed to chemical pesticide

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