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Fulltext Chlorpyrifos blood level and exposure symptoms among paddy farmers in Sabak Bernam, Malaysia

Rozita Hod, Azimatun Noor Aizuddin, Shamsul Azhar Shah, Mohd Rohaizat Hassan, Nazarudin Safian, Mohd Hasni Jaafar

Int J Public Health Res, 2011;1(1):1-6.
MyJurnal

Accepted 21 July 2011.
Introduction The extensive and intensive use of pesticides in agricultural practices has exposed farmers to various hazards resulting in varying degrees of health
outcomes.
Methods We conducted a cross-sectional study among paddy farmers in Sabak Bernam district, Malaysia. The objective of this study was to gather baseline information on chlorpyrifos blood level and its relationship with pesticides exposure symptoms.
Results We detected chlorpyrifos in farmers’ blood in 7 percent of the respondents, with mean 7.29 nanogram per millilitre blood (sd 5.84 nanogram per millilitre). The percentage of farmers who experienced at least one pesticide exposure symptoms was 75 percent. However, we found no significant association between chlorpyrifos blood level and its exposure symptoms. The farmers had low scores on safe practice of pesticide use even though they have high marks on knowledge and attitude. We found no significant association between the scores on knowledge, attitude and practice on pesticide use and the chlorpyrifos blood level.
Conclusions The presence of pesticide exposure symptoms proved that most of the farmers were exposed to hazardous effects of pesticides. Specific trainings on safe use and handling of pesticides should be given on regular basis to these farmers to ensure they are protected from hazardous effects of pesticides exposure.

Matched MeSH terms: Pesticides
Fulltext Adsorption and desorption study of ¹⁴C-chlorpyrifos in two Malaysian agricultural soils

Halimah Muhamad, Nashriyah Mat, Tan, Yew Ai, Ismail, B.S.

Journal of Nuclear and Related Technologies, 2004;2004(1):23-33.
MyJurnal

The adsorption equilibrium time and effects of pH and concentration of ¹⁴C-labeled chlorpyrifos
O,O-diethyl O-(3, 5, 6 trichloro-2-pyridyl)-phosphorothiote in soil were investigated. Two types of Malaysian soil under oil palm were used in this study; namely clay loam and clay soil obtained from the Sungai Sedu and Kuala Lumpur International Airport (KLIA) Estates, respectively. Equilibrium studies of chlorpyrifos between the agricultural soil and the pesticide solution were conducted. Adsorption equilibrium time was achieved within 6 and 24 hours for clay loam and clay soil, respectively. It was found that chlorpyrifos adsorbed by the soil samples was characterized by an initial rapid adsorption after which adsorption remained approximately constant. The percentage of ¹⁴C-labeled chlorpyrifos adsorption on soil was found to be higher in clay loam than in clay soils. Results of the study demonstrated that pH affected the adsorption of chlorpyrifos on both clay loam and clay soils. The adsorption of chlorpyrifos on both types of soil was higher at low pH with the adsorption reduced as the pH increased. Results also suggest that chlorpyrifos sorption by soil is concentration dependent.

Matched MeSH terms: Pesticides
Occurrence of commonly used pesticides in personal air samples and their associated health risk among paddy farmers

Hamsan H, Ho YB, Zaidon SZ, Hashim Z, Saari N, Karami A

Sci Total Environ, 2017 Dec 15;603-604:381-389.
PMID: 28633115 DOI: 10.1016/j.scitotenv.2017.06.096

Tanjung Karang, Selangor, is widely known for its paddy cultivation activity and hosts the third largest paddy field in Malaysia. Pesticides contamination in agriculture fields has become an unavoidable problem, as pesticides are used to increase paddy productivity and reduce plant disease. Human exposure to agrichemicals is common and could results in both acute and chronic health effects, such as acute and chronic neurotoxicity. This study aims to determine the concentrations of commonly used pesticides (azoxystrobin, buprofezin, chlorantraniliprole, difenoconazole, fipronil, imidacloprid, isoprothiolane, pretilachlor, propiconazole, pymetrozine, tebuconazole, tricyclazole, and trifloxystrobin) in personal air samples and their associated health risks among paddy farmers. Eighty-three farmers from Tangjung Karang, Selangor were involved in this study. A solid sorbent tube was attached to the farmer's breathing zone with a clip, and an air pump was fastened to the belt to collect personal air samples. Pesticides collected in the XAD-2 resin were extracted with acetone, centrifuged, concentrated via nitrogen blowdown and reconstituted with 1mL of 3:1 ultrapure water/HPLC-grade methanol solution. The extract was analyzed using ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). The target compounds were detected with a maximum concentration reaching up to 462.5ngm-3 (fipronil). The hazard quotient (HQ) was less than 1 and the hazard index (HI) value was 3.86×10-3, indicating that the risk of pesticides related diseases was not significant. The lifetime cancer risk (LCR) for pymetrozine was at an acceptable level (LCR<10-6) with 4.10×10-8. The results reported in this study can be beneficial in terms of risk management within the agricultural community.

Matched MeSH terms: Pesticides/adverse effects; Pesticides/analysis*
Ecological risk estimation of organophosphorus pesticides in riverine ecosystems

Wee SY, Aris AZ

Chemosphere, 2017 Dec;188:575-581.
PMID: 28917209 DOI: 10.1016/j.chemosphere.2017.09.035

Pesticides are of great concern because of their existence in ecosystems at trace concentrations. Worldwide pesticide use and its ecological impacts (i.e., altered environmental distribution and toxicity of pesticides) have increased over time. Exposure and toxicity studies are vital for reducing the extent of pesticide exposure and risk to the environment and humans. Regional regulatory actions may be less relevant in some regions because the contamination and distribution of pesticides vary across regions and countries. The risk quotient (RQ) method was applied to assess the potential risk of organophosphorus pesticides (OPPs), primarily focusing on riverine ecosystems. Using the available ecotoxicity data, aquatic risks from OPPs (diazinon and chlorpyrifos) in the surface water of the Langat River, Selangor, Malaysia were evaluated based on general (RQm) and worst-case (RQex) scenarios. Since the ecotoxicity of quinalphos has not been well established, quinalphos was excluded from the risk assessment. The calculated RQs indicate medium risk (RQm = 0.17 and RQex = 0.66; 0.1 ≤ RQ 1 (high risk) was observed for both the general and worst cases of chlorpyrifos, but only for the worst cases of diazinon at all sites from downstream to upstream regions. Thus, chlorpyrifos posed a higher risk than diazinon along the Langat River, suggesting that organisms and humans could be exposed to potentially high levels of OPPs.

Matched MeSH terms: Pesticides/analysis*; Pesticides/toxicity
Fulltext Residual analysis of chitosan-based agronanofungicides as a sustainable alternative in oil palm disease management

Maluin FN, Hussein MZ, Yusof NA, Fakurazi S, Maznah Z, Idris AS, et al.

Sci Rep, 2020 12 18;10(1):22323.
PMID: 33339951 DOI: 10.1038/s41598-020-79335-6

The nanoformulations of pesticides have shown great interest from many parties due to their slow release capability and site-specific delivery. Hence, in this work, a new nanoformulation of a fungicide, namely chitosan-hexaconazole nanoparticles with a mean diameter size of 18 nm was subjected to the residual analysis on oil palm tissue, leaf and palm oil (crude palm oil and crude palm kernel oil) using a quick, easy, cheap, effective, rugged and safe (QuEChERS) method coupled with the gas chromatography-micro electron capture detector (GC-µECD). The chitosan-hexaconazole nanoparticles were applied using the trunk injection method at 4.5 g a.i./palm (standard single dose) and 9.0 g a.i./palm (double dose). The fungicide residue was analyzed at 0 (6 h after application), 1, 3, 7, 14, 30, 60, 90, and 120 days after treatment. The palm oil matrices; the crude palm oil (CPO) and crude palm kernel oil (CPKO) were found to be residue-free. However, it was observed that high accumulation of the fungicide in the stem tissue and leaf after the treatment using the chitosan-hexaconazole nanoparticles, which is good for better bioavailability for the treatment of the fungi, Ganoderma boninense. The dissipation kinetic at double dose treatment in the tissue and leaf was found to govern by the second-order kinetic with half-lives (t1/2) of 383 and 515 days, respectively.

Matched MeSH terms: Pesticides/pharmacology*; Pesticides/chemistry
Fulltext Analytical Extraction Methods and Sorbents' Development for Simultaneous Determination of Organophosphorus Pesticides' Residues in Food and Water Samples: A Review

Veloo KV, Ibrahim NAS

Molecules, 2021 Sep 10;26(18).
PMID: 34576966 DOI: 10.3390/molecules26185495

Extensive use of organophosphorus pesticides in agriculture leads to adverse effects to the environment and human health. Sample preparation is compulsory to enrich target analytes prior to detection as they often exist at trace levels and this step is critical as it determines the concentration of pollutants present in samples. The selection of a suitable extraction method is of great importance. The analytical performance of the extraction methods is influenced by the selection of sorbents as sorbents play a vital role in the sensitivity and selectivity of an analytical method. To date, numerous sorbent materials have been developed to cater to the needs of selective and sensitive pesticides' detection. Comprehensive details pertaining to extraction methods, developed sorbents, and analytical performance are provided. This review intended to provide a general overview on different extraction techniques and sorbents that have been developed in the last 10 years for organophosphorus pesticides' determinations in food and water samples.

Matched MeSH terms: Pesticides/analysis; Pesticides/isolation & purification
Application of continual injection liquid-phase microextraction method coupled with liquid chromatography to the analysis of organophosphorus pesticides

Raharjo Y, Sanagi MM, Ibrahim WA, Naim AA, Aboul-Enein HY

J Sep Sci, 2009 Feb;32(4):623-9.
PMID: 19165835 DOI: 10.1002/jssc.200800566

A liquid-phase microextraction coupled with LC method has been developed for the determination of organophosphorus pesticides (methidation, quinalphos and profenofos) in drinking water samples. In this method, a small amount (3 microL) of isooctane as the acceptor phase was introduced continually to fill-up the channel of a 1.5 cm polypropylene hollow fiber using a microsyringe while the hollow fiber was immersed in an aqueous donor solution. A portion of the acceptor phase (ca. 0.4 microL) was first introduced into the hollow fiber and additional amounts (ca. 0.2 microL) of the acceptor phase were introduced to replenish at intervals of 3 min until set end of extraction (40 min). After extraction, the acceptor phase was withdrawn and transferred into a 2 mL vial for a drying step prior to injection into a LC system. Parameters that affect the extraction efficiency were studied including the organic solvent, length of fiber, volume of acceptor and donor phase, stirring rate, extraction time, and effect of salting out. The proposed method provided good enrichment factors of up to 189.50, with RSD ranging from 0.10 to 0.29%, analyte recoveries of over 79.80% and good linearity ranging from 10.0 to 1.25 mg/L. The LOD ranged from 2.86 to 82.66 microg/L. This method was applied successfully to the determination of organophosphorus pesticides in selected drinking water samples.

Matched MeSH terms: Pesticides/analysis*; Pesticides/chemistry*
Fulltext Dehalogenases: From Improved Performance to Potential Microbial Dehalogenation Applications

Ang TF, Maiangwa J, Salleh AB, Normi YM, Leow TC

Molecules, 2018 05 07;23(5).
PMID: 29735886 DOI: 10.3390/molecules23051100

The variety of halogenated substances and their derivatives widely used as pesticides, herbicides and other industrial products is of great concern due to the hazardous nature of these compounds owing to their toxicity, and persistent environmental pollution. Therefore, from the viewpoint of environmental technology, the need for environmentally relevant enzymes involved in biodegradation of these pollutants has received a great boost. One result of this great deal of attention has been the identification of environmentally relevant bacteria that produce hydrolytic dehalogenases—key enzymes which are considered cost-effective and eco-friendly in the removal and detoxification of these pollutants. These group of enzymes catalyzing the cleavage of the carbon-halogen bond of organohalogen compounds have potential applications in the chemical industry and bioremediation. The dehalogenases make use of fundamentally different strategies with a common mechanism to cleave carbon-halogen bonds whereby, an active-site carboxylate group attacks the substrate C atom bound to the halogen atom to form an ester intermediate and a halide ion with subsequent hydrolysis of the intermediate. Structurally, these dehalogenases have been characterized and shown to use substitution mechanisms that proceed via a covalent aspartyl intermediate. More so, the widest dehalogenation spectrum of electron acceptors tested with bacterial strains which could dehalogenate recalcitrant organohalides has further proven the versatility of bacterial dehalogenators to be considered when determining the fate of halogenated organics at contaminated sites. In this review, the general features of most widely studied bacterial dehalogenases, their structural properties, basis of the degradation of organohalides and their derivatives and how they have been improved for various applications is discussed.

Matched MeSH terms: Pesticides/metabolism; Pesticides/chemistry
Magnetite-sporopollenin/graphene oxide as new preconcentration adsorbent for removal of polar organophosphorus pesticides in vegetables

Markus A, Gbadamosi AO, Yusuff AS, Agi A, Oseh J

Environ Sci Pollut Res Int, 2018 Dec;25(35):35130-35142.
PMID: 30328041 DOI: 10.1007/s11356-018-3402-3

In this study, a new magnetic adsorbent based on magnetite-sporopollenin/graphene oxide (Fe3O4-SP/GO) was successfully developed. The adsorbent was applied for magnetic solid phase extraction (MSPE) of three selected polar organophosphorus pesticides (OPPs), namely, dimethoate, phenthoate, and phosphamidon, prior to gas chromatography analysis with electron capture detection (GC-μECD). The Fe3O4-SP/GO adsorbent combines the advantages of superior adsorption capability of the modified sporopollenin (SP) with graphene oxide (GO) and magnetite (Fe3O4) for easy isolation from sample solution. Several MSPE parameters were optimized. Under optimized conditions, excellent linearity (R2 ≥ 0.9994) was achieved using matrix match calibration in the range of 0.1 to 500 ng mL-1. The limit of detection (LOD) method (S/N = 3) was from 0.02 to 0.05 ng mL-1. The developed Fe3O4-SP/GO MSPE method was successfully applied for the determination of these three polar OPPs in cucumber, long beans, bell pepper, and tomato samples. Good recoveries (81.0-120.0%) and good relative standard deviation (RSD) (1.4-7.8%, n = 3) were obtained for the spiked OPPs (1 ng mL-1) from real samples. This study is beneficial for adsorptive removal of toxic pesticide compounds from vegetable samples.

Matched MeSH terms: Pesticides/analysis; Pesticides/chemistry*
A review on colorimetric methods for determination of organophosphate pesticides using gold and silver nanoparticles

Che Sulaiman IS, Chieng BW, Osman MJ, Ong KK, Rashid JIA, Wan Yunus WMZ, et al.

Mikrochim Acta, 2020 01 15;187(2):131.
PMID: 31940088 DOI: 10.1007/s00604-019-3893-8

This review (with 99 refs.) summarizes the progress that has been made in colorimetric (i.e. spectrophotometric) determination of organophosphate pesticides (OPPs) using gold and silver nanoparticles (NPs). Following an introduction into the field, a first large section covers the types and functions of organophosphate pesticides. Methods for colorimetric (spectrophotometric) measurements including RGB techniques are discussed next. A further section covers the characteristic features of gold and silver-based NPs. Syntheses and modifications of metal NPs are covered in section 5. This is followed by overviews on enzyme inhibition-based assays, aptamer-based assays and chemical (non-enzymatic) assays, and a discussion of specific features of colorimetric assays. Several Tables are presented that give an overview on the wealth of methods and materials. A concluding section addresses current challenges and discusses potential future trends and opportunities. Graphical abstractSchematic representation of organophosphate pesticide determinations based on aggregation of nanoparticles (particular silver or gold nanoparticles). This leads to a color change which can be determined visually and monitored by a red shift in the absorption spectrum.

Matched MeSH terms: Pesticides/analysis*; Pesticides/chemistry
Predictors of Detected Organophosphorus Pesticides Among Orang Asli Children Living in Malaysia

Mat Sutris J, Md Isa Z, Sumeri SA, Ghazi HF

Ann Glob Health, 2017 3 12;82(5):770-778.
PMID: 28283128 DOI: 10.1016/j.aogh.2016.10.008

BACKGROUND: Increasing use of pesticides in agriculture to control pest may result in permanent damage to the environment and consequently cause harmful health problems especially among infant and children. Due to pesticide's natural toxicity and its widespread use, it causes a serious threat to public health especially to this vulnerable group.
OBJECTIVE: The purpose of this study was to determine the organophosphorus pesticide urinary metabolite levels and its predictors among Orang Asli children of the Mah Meri tribe living in an agricultural island in Kuala Langat, Selangor.
METHODS: Data collection was carried out at an island in Kuala Langat, Selangor, where a total of 180 Orang Asli children of the Mah Meri tribe voluntarily participated in the study. Data were collected via a validated, modified questionnaire. Urinary organophosphate metabolites, namely dimethylphosphate, diethylphosphate, dimethylthiophosphate, dimethyldithiophosphate, diethylthiophosphate, and diethyldithiophosphate were measured to assess organophosphate pesticide exposure in children.
FINDINGS: Eighty-four (46.7%) of the respondents were positive for urine dialkyl phosphate metabolites. In multivariable analysis, children who frequently consumed apples had 4 times higher risk of pesticide detection than those who consumed apple less frequently. In addition, those who frequently ate cucumbers had 4 times higher risk for pesticide detection than those who ate cucumbers less frequently. Children with a father whose occupation involved high exposure to pesticides (agriculture) had 3 times higher risk of pesticide detection than those with a father in a low-risk occupation (nonagriculture).
CONCLUSIONS: Almost half of the children (46.7%) in the study area tested positive for urinary dialkyl phosphate metabolite levels. Most of the metabolite levels were equal to or higher than that reported in other previous studies. Major factors associated with pesticide detection in children in this study were frequent intake of apple and cucumber and fathers who are working in an agricultural area.

Matched MeSH terms: Pesticides/adverse effects*; Pesticides/urine
The use of date palm as a potential adsorbent for wastewater treatment: a review

Ahmad T, Danish M, Rafatullah M, Ghazali A, Sulaiman O, Hashim R, et al.

Environ Sci Pollut Res Int, 2012 Jun;19(5):1464-84.
PMID: 22207239 DOI: 10.1007/s11356-011-0709-8

BACKGROUND: In tropical countries, the palm tree is one of the most abundant and important trees. Date palm is a principal fruit grown in many regions of the world. It is abundant, locally available and effective material that could be used as an adsorbent for the removal of different pollutants from aqueous solution.
REVIEW: This article presents a review on the role of date palm as adsorbents in the removal of unwanted materials such as acid and basic dyes, heavy metals, and phenolic compounds. Many studies on adsorption properties of various low cost adsorbent, such as agricultural waste and activated carbons based on agricultural waste have been reported in recent years.
CONCLUSION: Studies have shown that date palm-based adsorbents are the most promising adsorbents for removing unwanted materials. No previous review is available where researchers can get an overview of the adsorption capacities of date palm-based adsorbent used for the adsorption of different pollutants. This review provides the recent literature demonstrating the usefulness of date palm biomass-based adsorbents in the adsorption of various pollutants.

Matched MeSH terms: Pesticides/isolation & purification; Pesticides/chemistry
Is plasma beta-glucuronidase a novel human biomarker for monitoring anticholinesterase pesticides exposure? A Malaysian experience

Inayat-Hussain SH, Lubis SH, Sakian NI, Ghazali AR, Ali NS, El Sersi M, et al.

Toxicol Appl Pharmacol, 2007 Mar;219(2-3):210-6.
PMID: 17140616

A cross-sectional study was conducted to investigate the effects of acute and chronic pesticide exposure on the plasma beta-glucuronidase enzyme activity among five patients of acute pesticide poisoning in Tengku Ampuan Rahimah Hospital, Klang, 230 farmers in the MADA area, Kedah and 49 fishermen in Setiu, Terengganu. The duration of pesticide exposure among the patients was unknown, but the plasma samples from patients were collected on day one in the hospital. The duration of pesticide exposure among the farmers was between 1 and 45 years. The beta-glucuronidase activity was compared with plasma cholinesterase activity in the same individual. The plasma cholinesterase activity was measured using Cholinesterase (PTC) Reagent set kit (Teco Diagnostics, UK) based on colorimetric method, while the plasma beta-glucuronidase activity was measured fluorometrically based on beta-glucuronidase assay. The plasma cholinesterase activity was significantly reduced (p<0.05) among the patients (1386.786+/-791.291 U/L/min) but the inhibition in plasma cholinesterase activity among the farmers (7346.5+/-1860.786 U/L/min) was not significant (p>0.05). The plasma beta-glucuronidase activity among the farmers was significantly elevated (p<0.05) (0.737+/-0.425 microM/h) but not significant among the patients (p>0.05). The plasma cholinesterase activity was positively correlated with the plasma beta-glucuronidase activity among the farmers (r=0.205, p<0.01) but not among the patients (r=0.79, p>0.05). Thus, plasma beta-glucuronidase enzyme activity can be measured as a biomarker for the chronic exposure of pesticide. However, further studies need to be performed to confirm whether plasma beta-glucuronidase can be a sensitive biomarker for anticholinesterase pesticide poisoning.

Matched MeSH terms: Pesticides/analysis; Pesticides/toxicity*
Fulltext An initial study of knowledge, attitude and practices (KAP) of pesticides use among oil palm workers in Johor

Marina Mior, S.N., Leman, A.M., Masripan, R., Baharudin, M.R., M. Faazir T., M. Ifwat A.

Journal of Occupational Safety and Health, 2016;13(2):117-121.
MyJurnal

An awareness of possible risk factor in pesticides, by changing attitude towards the correct technique during spraying and
changing behavior can increase safety of workers safety as well as performance. However, there is a limited study and not highlighted
deeply in knowledge, attitude and practices of workers in palm oil plantation issue. Therefore , the objective of this paper is to identify
the relationship between knowledge, attitude and practices of pesticides among the plantation workers. The quantitative method were
used in this paper whereby 132 respondents as pesticide sprayer which represent 90% of the population of palm oil workers in Johor.
The result of spearman correlation indicates that there is significant relationship between knowledge and practices. It shows the
common pattern of high knowledge resulting high practices of the workers during spraying the pesticides at plantation. There is no
relationship between knowledge and attitude and between attitude and practice of the workers at the workplace. This paper shows that
knowledge need to be strengthen in agricultural communities of Johor in order to reduce health problem and sosial issue statistic and
prevent for any future accident. Human exposure to pesticides is an important health and sosial issue as it usually results in serious
health problems such as stroke, epilepsy, respiratory disorders and cancer. Death has been known to occur in some places as a result
of exposures to pesticides. Therefore, more impact knowledge-focused programs need to be arranged and implemented to inculcate
the better awareness of pesticides among palm oil workers, as without knowledge, people may become less careful and therefore are
exposed to pesticide poisoning and other long term exposure illness in the future.

Matched MeSH terms: Pesticides
Fulltext Effects of herbicides on fungal phytopathogens

Durgadevi Mohan, Ho, Pei Yin, Ho, Chai Ling, Parameswari Namasivayam, Noor Baity Saidi

The Pertanika Journal of Scholarly Research Reviews, 2017;3(3):93-101.
MyJurnal

Herbicides are inevitable inputs to control excessive weed in crop land, particularly where modern agricultural practices such as conservation tillage, are opted. Intensive farming has increased the market value of herbicides among the other pesticides. Although herbicides are effective in controlling weed population, administration of this synthetic chemicals may alter the soil microbial community causing potential increase of plant pathogens. Moreover, herbicides may also have nontarget effects on the cultivated crops making them more susceptible to diseases. Actions of herbicides in soil that either stimulate microbial growth or wipe out some microbial population may create space for the thrivial of opportunistic fungi. Previous studies showed that white rot fungi are more tolerant to herbicides as they produce lignin degrading enzymes that are highly oxidative, non-specific and are able to transform a wide range of herbicides. Besides that, this group of fungi can grow on agricultural waste substrates. Influence of these herbicides on soil microbial ecosystem and interactions of plants and pathogenic white rot fungi modulate disease development in plant hosts.

Matched MeSH terms: Pesticides
Proteomics as a tool for tapping potential of entomopathogens as microbial insecticides

Harith Fadzilah N, Abdul-Ghani I, Hassan M

Arch Insect Biochem Physiol, 2019 Jan;100(1):e21520.
PMID: 30426561 DOI: 10.1002/arch.21520

Biopesticides are collective pest control harnessing the knowledge of the target pest and its natural enemies that minimize the risks of synthetic pesticides. A subset of biopesticides; bioinsecticides, are specifically used in controlling insect pests. Entomopathogens (EPMs) are micro-organisms sought after as subject for bioinsecticide development. However, lack of understanding of EPM mechanism of toxicity and pathogenicity slowed the progress of bioinsecticide development. Proteomics is a useful tool in elucidating the interaction of entomopathogenic fungi, entomopathogenic bacteria, and entomopathogenic virus with their target host. Collectively, proteomics shed light onto insect host response to EPM infection, mechanism of action of EPM's toxic proteins and secondary metabolites besides characterizing secreted and membrane-bound proteins of EPM that more precisely describe relevant proteins for host recognition and mediating pathogenesis. However, proteomics requires optimized protein extraction methods to maximize the number of proteins for analysis and availability of organism's genome for a more precise protein identification.

Matched MeSH terms: Pesticides
Biological Control of Diamondback Moth, Plutella xylostella (L.),Using Parasitoids and Bacteria: A Review

Idris A.B., Norhayati Abdul Mukti

Sains Malaysiana, 1997;26.

Resistance of diamondback moth (DBM), Plutella xylostela (L), to coventional pesticides and concerns about environmental quality have lead to increased worldwide efforts to develop viable biocontrol methods for DBM. The success of using parasitoids, especially larval parasitoids like Diadegma, Cotesia and Microplitis species for controlling DBM have been reported in several countries. These larval parasitoids of DBM are commonly found in the field. Diadegma semiclausum (=eucerophaga) Hellen is the major parasitoid of DBM in Europe and Asia, while Diadegma insulare (Cresson) are predominates in the Americas. To date, the bacterium, Bacillus thuringiensis Berliner subspecies kurstaki, has been the most widely used DBM pathogen. Although it is environment friendly pesticides, its effectiveness always vary with weather, field location and frequency of application per season. These are the main factors that contribute to the slow acceptance of B.thuringiensis by the cabbage growers worldwide. Because of this many studies have been done to improve its efficacay and persistence in the field. This paper provides an overview of the current status of these agents for use in controlling DBM and suggest research that is needed to improve the usefulness of these biocontrol agents and to maximize their impact on the DBM management in the future.
Ketahanan rama-rama belakang-intan (diamondback moth), Plutella xylostella (L.), kepada semua racun-racun perosak yang biasa digunakan untuk mengawalnya dan keprihatinan terhadap kualiti alam sekitar telah menyebabkan bertambahnya usaha mencari beberapa kaedah kawalan biologi rama-rama ini di seluruh dunia. Kejayaan menggunakan parasitoids, terutamanya parasitoid larva seperti spesies Diadegma, Cotesia dan Microplitis bagi kawalan serangga ini telah dilaporkan oleh beberapa negara. Parasitoid-parasitoid larva ini mudah didapati di lapangan. Diadegma semiclausum (=eucerophaga) Hellen adalah merupakan parasitoid utama di Eropah dan Asia, sementara Diadegma insulare (Cresson) predominen di benua America. Sehingga kini, bakteria Bacillus thuringiensis Berliner subspesies kurstaki, adalah sejenis patogen serangga yang digunakan secara meluas untuk mengawal rama-rama tersebut. Walaupun B. thuringiensis adalah sejenis racun makhluk perosak yang tidak mencemari alam sekitar, tahap keberkesanan tindakannya adalah kerap berubah-ubah mengikut perubahan cuaca, lokasi lapangan dan kekerapan penggunaannya. Ini adalah merupakan faktor-faktor penting yang menyebabkan kelambatan penerimaannya oleh penanam-penanam kobis di merata dunia. Oleh sebab inilah banyak kajian telah dan sedang dijalankan bagi memperbaiki tahap keberkesanan dan persistentnya di lapangan. Kertas ini disedia bagi memperihalkan status penggunaan kedua-dua jenis agen kawalan biologi disamping mengesyurkan penyelidikan yang perlu dibuat untuk mempertingkatkan kegunaan dan memaksimumkan dampaknya dalam pengurusan rama-rama ini masa akan datang.

Matched MeSH terms: Pesticides
Equilibrium, kinetic and thermodynamic study of pesticides removal from water using novel glucamine-calix[4]arene functionalized magnetic graphene oxide

Nodeh HR, Kamboh MA, Wan Ibrahim WA, Jume BH, Sereshti H, Sanagi MM

Environ Sci Process Impacts, 2019 Apr 17;21(4):714-726.
PMID: 30869668 DOI: 10.1039/c8em00530c

A novel nanocomposite of MGO-NGC, composed of magnetic Fe3O4 nanoparticles (M), graphene oxide (GO), and N-methyl-d-glucamine functionalized calix[4]arene (NGC), was synthesized and applied as an effective adsorbent for the removal of two selected pesticides, namely hexaconazole and chlorpyrifos from water samples. The adsorbent was characterized by FTIR, SEM, EDX, TEM, and XRD. The main parameters affecting the adsorption process such as adsorbent dosage, pH of sample solution, salt effect, pesticide concentration, and adsorption time were investigated. The data from kinetic studies fitted well to the pseudo-second order kinetic model with R2 > 0.99. Among the isotherm models of Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich, the Langmuir isotherm fitted well to the adsorption process and demonstrated the monolayer adsorption pattern of the pesticides. Moreover, high adsorption capacities of 78.74 and 93.46 mg g-1 were obtained for chlorpyrifos and hexaconazole, respectively. Thermodynamic and free energy data indicated the physisorption mechanism for the adsorption process. The new adsorbent can be employed as an efficient, environment friendly, and highly reusable alternative for the removal of chlorinated pesticides from aqueous media.

Matched MeSH terms: Pesticides
Multimedia environmental fate and transport model of dichlorodiphenyltrichloroethane (DDT): case study sayong river watershed, Johor, Malaysia

Ghani Z, Anuar A, Majid Z, Yoneda M

Sains Malaysiana, 2017;46:2383-2392.

This study describes the development of a multimedia environmental fate and transport model of dichlorodiphenyltrichloroethane (DDT) at Sungai Sayong watershed. Based on the latest estimated DDT emission, the DDT concentrations in air, soil, water and sediment as well as the transfer processes were simulated under the equilibrium and steady-state assumption. Model predictions suggested that soil and sediment was the dominant sink of DDT. The results showed that the model predicted was generally good agreement with field data. Compared with degradation reaction, advection outflow was more important processes occurred in the model. Sensitivities of the model estimates to input parameters were tested. The result showed that vapour pressure (Ps) and organic carbon water partition coefficient (KOC) were the most influential parameters for the model output. The model output-concentrations of DDT in multimedia environment is very important as it can be used in future for human exposure and risk assessment of organochlorine pesticides (OCPs) at Sungai Sayong Basin.

Matched MeSH terms: Pesticides
Fulltext Pesticide application, dermal exposure risk and factors influenced distribution on different body parts among agriculture workers

Nurulain M, Syed Ismail S, Emilia Z, Vivien H

Malaysian Journal of Public Health Medicine, 2017;17 Special(1):123-132.

Agriculture sector accounts significant numbers of injuries and fatalities in the workplace particularly related to pesticide management. Among three main pathways of pesticide exposure, dermal contact is the most common route, which exposure usually occurs during pesticide mixing/loading, application, harvesting and other farming activities. This review aims to present and discuss several vital components of pesticide dermal exposure among agriculture workers, as well as pesticide application in agriculture sector in Malaysia involving different commodity agriculture sub-sectors. Pesticide exposure was discussed from perspective of three pesticide management activities (i.e. preparation, application and cleaning) that contribute to the risk of exposure through three routes (i.e. emission, deposition, transfer). Moreover, this paper also discussed pesticide dermal exposure risk assessment methods which can be defined into exposure assessment and effect assessment. The exposure rate was affected by various factors such as application equipment, application rate and duration, type of pesticide formulation, pesticide management stage, usage of personal protective equipment, training and aptitude of the applicator as well as environmental factors (i.e. temperature, humidity, wind speed and direction). The factors mention earlier have been used to explain the exposure distribution over different parts of the body and support the fact that pesticide type was not a major factor in total exposure.

Matched MeSH terms: Pesticides

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