Application Of Chlorpyrifos Research Articles

Longitudinal assessment of occupational exposures to the organophosphorous insecticides chlorpyrifos and profenofos in Egyptian cotton field workers.

Chlorpyrifos (CPF) and profenofos (PFF) are organophosphorus (OP) insecticides that are applied seasonally in Egypt to cotton fields. Urinary trichloro-2-pyridinol (TCPy), a specific CPF metabolite, and 4-bromo-2-chlorophenol (BCP), a specific PFF metabolite, are biomarkers of exposure, while inhibition of blood butyrylcholinesterase (BChE) and acetylcholinesterase (AChE) activities are effect biomarkers that may be associated with neurotoxicity. Urinary TCPy and BCP and blood BChE and AChE activities were measured in 37 adult Egyptian Ministry of Agriculture workers during and after 9-17 consecutive days of CPF application followed by an application of PFF (9-11 days), and a second CPF application (5 days) in 2008. During the OP applications, urinary TCPy and BCP levels were significantly higher than baseline levels, remained elevated following the application periods, and were associated with an exposure related inhibition of blood BChE and AChE. Analysis of blood AChE levels before and after the PFF application period suggests that individual workers with peak BCP levels greater than 1000 μg/g creatinine exhibited further inhibition of blood AChE with PFF application, demonstrating that PFF exposure had a negative impact on AChE activity in this highly exposed worker population. While large interindividual differences in exposure were observed throughout this longitudinal study (peak urinary BCP and peak TCPy levels for individuals ranging from 13.4 to 8052 and 16.4 to 30,107 μg/g creatinine, respectively), these urinary biomarkers were highly correlated within workers (r=0.75, p<0.001). This suggests that the relative exposures to CPF and PFF were highly correlated for a given worker. The variable exposures between job classification and work site suggest that job title and work location should not be used as the sole basis for categorizing OP exposures when assessing neurobehavioral and other health outcomes in Egyptian cotton field workers. Together, these findings will be important in educating the Egyptian insecticide application workers in order to encourage the development and implementation of work practices and personal protective equipment to reduce their exposure to CPF and PFF.

Potential Dermal Exposure and Risk Assessment for Applicators of Chlorothalonil and Chlorpyrifos in Cucumber Greenhouses in China

ABSTRACTOccupational exposure to pesticides has not been conducted in depth so far in China. The potential dermal exposure and risk assessment were conducted for applicators through application with a knapsack power sprayer in cucumber greenhouses. The spray suspension was prepared with 75% chlorothalonil WP and 48% chlorpyrifos EC. The dermal patch method was applied to assess the potential dermal exposure (PDE) of applicators during application. The average total PDE on the whole body of applicators during application of chlorothalonil and chlorpyrifos was 83.2 mL h−1 and 85.1 mL h−1, respectively. The most exposed part of the body was arms, especially the right arm. For risk assessment, the margin of safety (MOS) was calculated from the PDE. The MOS values were 0.1 and 0.2 for application of chlorothalonil and chlorpyrifos, respectively, both less than 1, which indicated low possibility of health risk.

Neurodevelopmental disorders and prenatal residential proximity to agricultural pesticides: the CHARGE study.

Background: Gestational exposure to several common agricultural pesticides can induce developmental neurotoxicity in humans, and has been associated with developmental delay and autism.Objectives: We evaluated whether residential proximity to agricultural pesticides during pregnancy is associated with autism spectrum disorders (ASD) or developmental delay (DD) in the Childhood Autism Risks from Genetics and Environment (CHARGE) study.Methods: The CHARGE study is a population-based case–control study of ASD, DD, and typical development. For 970 participants, commercial pesticide application data from the California Pesticide Use Report (1997–2008) were linked to the addresses during pregnancy. Pounds of active ingredient applied for organophophates, organochlorines, pyrethroids, and carbamates were aggregated within 1.25-km, 1.5-km, and 1.75-km buffer distances from the home. Multinomial logistic regression was used to estimate the odds ratio (OR) of exposure comparing confirmed cases of ASD (n = 486) or DD (n = 168) with typically developing referents (n = 316).Results: Approximately one-third of CHARGE study mothers lived, during pregnancy, within 1.5 km (just under 1 mile) of an agricultural pesticide application. Proximity to organophosphates at some point during gestation was associated with a 60% increased risk for ASD, higher for third-trimester exposures (OR = 2.0; 95% CI: 1.1, 3.6), and second-trimester chlorpyrifos applications (OR = 3.3; 95% CI: 1.5, 7.4). Children of mothers residing near pyrethroid insecticide applications just before conception or during third trimester were at greater risk for both ASD and DD, with ORs ranging from 1.7 to 2.3. Risk for DD was increased in those near carbamate applications, but no specific vulnerable period was identified.Conclusions: This study of ASD strengthens the evidence linking neurodevelopmental disorders with gestational pesticide exposures, particularly organophosphates, and provides novel results of ASD and DD associations with, respectively, pyrethroids and carbamates.Citation: Shelton JF, Geraghty EM, Tancredi DJ, Delwiche LD, Schmidt RJ, Ritz B, Hansen RL, Hertz-Picciotto I. 2014. Neurodevelopmental disorders and prenatal residential proximity to agricultural pesticides: the CHARGE study. Environ Health Perspect 122:1103–1109; http://dx.doi.org/10.1289/ehp.1307044

Soil bacterial and fungal community successions under the stress of chlorpyrifos application and molecular characterization of chlorpyrifos-degrading isolates using ERIC-PCR

Chlorpyrifos is a widely used insecticide in recent years, and it will produce adverse effects on soil when applied on crops or mixed with soil. In this study, nested polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE) were combined to explore the bacterial and fungal community successions in soil treated with 5 and 20 mg/kg of chlorpyrifos. Furthermore, isolates capable of efficiently decomposing chlorpyrifos were molecular-typed using enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR). Under the experimental conditions, degradation of chlorpyrifos in soil was interpreted with the first-order kinetics, and the half-lives of chlorpyrifos at 5 and 20 mg/kg doses were calculated to be 8.25 and 8.29 d, respectively. DGGE fingerprint and principal component analysis (PCA) indicated that the composition of the fungal community was obviously changed with the chlorpyrifos treatment, and that samples of chlorpyrifos treatment were significantly separated from those of the control from the beginning to the end. While for the bacterial community, chlorpyrifos-treated soil samples were apparently different in the first 30 d and recovered to a similar level of the control up until 60 d, and the distance in the PCA between the chlorpyrifos-treated samples and the control was getting shorter through time and was finally clustered into one group. Together, our results demonstrated that the application of chlorpyrifos could affect the fungal community structure in a quick and lasting way, while only affecting the bacterial community in a temporary way. Finally, nine typical ERIC types of chlorpyrifos-degrading isolates were screened.

Alterations in Plasma and Tissue Acetylcholinesterase Activity Following Repeated Oral Exposure of Chlorpyrifos Alone and in Conjunction with Fluoride in Wistar Rats

Concurrent exposures of more than one environmental contaminants are commonly encountered by human beings and animals. This study investigated the effect of chlorpyrifos alone and in conjunction with fluoride on plasma and tissue acetylcholinesterase (AChE) activity in wistar rats. Fluoride at 1 or 10 ppm in drinking water produced significant (P < 0.05) inhibition of AChE activity in a dose dependant manner and inhibition was maximum in brain (26.39 %) and least in heart (10.23 %). Similarly repeated oral administration of chlorpyrifos at 1 or 10 mg/kg produced a significant dose dependant inhibition of AChE activity (P < 0.05) which was observed maximum in brain (28.93 %) and least in heart (12.86 %). Co-exposure of chlorpyrifos and fluoride at higher doses produces more pronounced inhibition as compared to chlorpyrifos or fluoride exposed groups. Co-exposure produces maximum inhibition in erythrocyte (37.54 %) and least in plasma (18.26 %) of exposed animals as compared to control group. Observations from the present study suggested that co-exposure of fluoride and chlorpyrifos produces more pronounced inhibition of AChE than the individual exposure of either toxicant. Therefore the applications of chlorpyrifos as a pesticide should be reduced in areas where fluoride level in soil or ground water is high to avoid AChE inhibition.

Behavior of pyrimethanil, pyraclostrobin, boscalid, cypermethrin and chlorpyrifos residues on raspberry fruit and leaves of Laszka variety

The purpose of the research conducted was to investigate and evaluate the behavior of pyrimethanil, pyraclostrobin, boscalid, cypermethrin and chlorpyrifos, the active ingredients of selected fungicides and insecticides, on ripe fruit and in fully developed leaves of raspberry of the Laszka variety. The field trial was carried out in the period of one month starting from the first fruit picking. The results obtained indicated that residue levels on the day of the first crop picking did not even approximate the corresponding EU-MRLs (http://ec.europa.eu/sanco_pesticides). Individual substances in raspberry fruits and leaves disappeared at a similar rate. As a result of chlorpyrifos application to the soil, its residue in fruits and leaves occurred for the whole period of fruit bearing, though in fruit they dropped successively. To produce raspberries with residues below or equal to 0.01 μg g−1, the application of pesticides should be stopped at least 2–3 weeks before the first crop picking, and on condition that an appropriate preparation (active in low doses) is applied to the last treatments.

Study on the Degradation of Chlorpyrifos by Immobilized &lt;i&gt;Bacillus&lt;/i&gt;

Pesticide pollutions have become increasingly severe. Especially the extensive production and application of chlorpyrifos have resulted in the environmental pollution and ecological damage. The employment of the immobilized microorganism degradation of chlorpyrifos in soil is a kind of effective technology without secondary pollution. The best ratio of immobilized carrier has been determined by comparison among different carriers for chlorpyrifos degradation. Based upon the adoption of Bacillus LLBD4, pH value, temperature and initial concentration of chlorpyrifos were studied in this experiment. The results showed that the combination of 10% of PVC, 1% of activated carbon and 0.5% sodium alginate can be served as the best carrier, furthermore, chlorpyrifos degradation efficiency reached the peak when the pH was set to 7.0, the initial concentration of chlorpyrifos was 100 mg·L-1at 30°C, reaching about 83%.

Degradation of chlorpyrifos in humid tropical soils

The insecticide chlorpyrifos is extensively used in the humid tropics for insect control on crops and soils. Chlorpyrifos degradation and mineralization was studied under laboratory conditions to characterize the critical factors controlling the degradation and mineralization in three humid tropical soils from Malaysia. The degradation was fastest in moist soils (t1/2 53.3–77.0 days), compared to dry (t1/2 49.5–120 days) and wet soils (t1/2 63.0–124 days). Degradation increased markedly with temperature with activation energies of 29.0–76.5 kJ mol−1. Abiotic degradation which is important for chlorpyrifos degradation in sub-soils containing less soil microbial populations resulted in t½ of 173–257 days. Higher chlorpyrifos dosages (5-fold) which are often applied in the tropics due to severe insects infestations caused degradation and mineralization rates to decrease by 2-fold. The mineralization rates were more sensitive to the chlorpyrifos application rates reflecting that degradation of metabolites is rate limiting and the toxic effects of some of the metabolites produced. Despite that chlorpyrifos is frequently used and often in larger amounts on tropical soils compared with temperate soils, higher temperature, moderate moisture and high activity of soil microorganisms will stimulate degradation and mineralization.

Aerial, ground and chemigation spray deposition on corn for the control of spodoptera frugiperda (lepidoptera: noctuidae)

Pesticides can be applied by aircraft, ground-sprayers or sprinkler irrigation. However, selecting the best option is complicated by the limited number of studies comparing these techniques. Thus, the objective of this work was to study the chlorpyrifos insecticide deposition applied by aircraft (30 L ha-1), tractor-mounted sprayer (200 L ha-1) and chemigation (70,000 L ha-1) for the control of Spodoptera frugiperda (J.E. Smith) in two corn (Zea mays L.) populations (70,000 and 100,000 plants ha-1). Active ingredient residue on the corn plant leaves was evaluated by gas chromatography, immediately and ten days after the treatments. Armyworm numbers in each plot and control were also evaluated. The experiment was set up in randomized blocks with four replications. Aerial and ground applications of chlorpyrifos led to greater active ingredient deposition in the leaves than chemigation. Neither plant population (70,000 and 100,000 plants ha-1) affected the insecticide deposition in the corn leaves. S. frugiperda control was similar for all three application methods. Chemigation, however, resulted in less deposition on the plants and consequently in a greater insecticide loss to the soil, which should be considered in environmental impact.

Longitudinal assessment of chlorpyrifos exposure and effect biomarkers in adolescent Egyptian agricultural workers

Chlorpyrifos (CPF) is applied seasonally in Egypt by adolescent agricultural workers and the extent of occupational exposure and the potential for environmental CPF exposure in this population is poorly understood. Adolescent pesticide applicators (n=57; 12-21 years of age) and age-matched non-applicators (n=38) from the same villages were followed for 10 months in 2010, spanning pre-application through post-application. Eight urine and five blood samples were collected from participants within this time period. Blood acetylcholinesterase and butyrylcholinesterase (BChE; exposure/effect biomarker) and urine 3,5,6-trichloro-2-pyridinol (TCPy; exposure biomarker) were used to assess occupational CPF exposures in pesticide applicators and environmental exposures in non-applicators. Applicators demonstrated significantly higher TCPy concentration and BChE depression than non-applicators throughout CPF application. This difference persisted for 4-7 weeks after the cessation of agricultural spraying. However, both groups exhibited significantly elevated TCPy and depressed BChE, compared with their respective baseline. The peak TCPy levels during the spray season (95% confidence interval (CI)) for non-applicators and applicators reached 16.8 (9.87-28.5) and 137 (57.4-329) ug/g creatinine, respectively. BChE levels (95% CIs) during the spray were as follows: 1.47 (1.28-1.68) for non-applicators and 0.47 (0.24-0.94) U/ml for applicators. The longitudinal assessment of CPF biomarkers provided robust measures of exposure and effect throughout CPF application in adolescents and revealed significant exposures in both applicators and non-applicators. Biomarker data in the non-applicators, which mirrored that of the applicators, indicated that non-applicators received environmental CPF exposures. This suggests that similar exposures may occur in other residents of this region during periods of pesticide application.

Chlorpyrifos contamination of fresh water in a commercial vegetable cultivation area in Sri Lanka and factors affecting contamination

The study investigated the interrelationships among chlorpyrifos (CPF) concentrations in water resources, CPF application and rainfall during peak pesticide application period with usual rainfall pattern. Water samples were collected at three day intervals from groundwater and surface water resources at Marassana, a commercial vegetable cultivation area in the Kandy District, Sri Lanka, during a 5-month period. CPF application and rainfall data were also collected simultaneously. High performance liquid chromatography analyses revealed that the average CPF concentration in groundwater and surface water samples were 0.63 and 0.52 μg/L, respectively. The respective corresponding maximum values were 7.1 and 3.7 μg/L. Multiple linear regression analysis of the data established that 1 L of CPF 40 % (= 400 g/L concentration) applied in the catchments increased the CPF concentration in the groundwater and surface water by 0.65 μg/L and 0.120 μg/L, respectively; 1 mm of cumulative rainfall received increased the CPF concentration of surface water by 0.021 μg/L but did not affect the groundwater concentration significantly. Uncertainties in the model parameters analysed using Monte Carlo stochastic simulation established that there was an 88 % probability for the CPF concentration to remain positive in the surface water. Doi: http://dx.doi.org/10.4038/jnsfsr.v40i4.5047 J.Natn.Sci.Foundation Sri Lanka 2012 40 (4): 333-344

PON1 status does not influence cholinesterase activity in Egyptian agricultural workers exposed to chlorpyrifos

Animal studies have shown that paraoxonase 1 (PON1) genotype can influence susceptibility to the organophosphorus pesticide chlorpyrifos (CPF). However, Monte Carlo analysis suggests that PON1 genotype may not affect CPF-related toxicity at low exposure conditions in humans. The current study sought to determine the influence of PON1 genotype on the activity of blood cholinesterase as well as the effect of CPF exposure on serum PON1 in workers occupationally exposed to CPF. Saliva, blood and urine were collected from agricultural workers (n=120) from Egypt's Menoufia Governorate to determine PON1 genotype, blood cholinesterase activity, serum PON1 activity towards chlorpyrifos-oxon (CPOase) and paraoxon (POase), and urinary levels of the CPF metabolite 3,5,6-trichloro-2-pyridinol (TCPy). The PON1 55 (P≤0.05) but not the PON1 192 genotype had a significant effect on CPOase activity. However, both the PON1 55 (P≤0.05) and PON1 192 (P≤0.001) genotypes had a significant effect on POase activity. Workers had significantly inhibited AChE and BuChE after CPF application; however, neither CPOase activity nor POase activity was associated with ChE depression when adjusted for CPF exposure (as determined by urinary TCPy levels) and stratified by PON1 genotype. CPOase and POase activity were also generally unaffected by CPF exposure although there were alterations in activity within specific genotype groups. Together, these results suggest that workers retained the capacity to detoxify chlorpyrifos-oxon under the exposure conditions experienced by this study population regardless of PON1 genotype and activity and that effects of CPF exposure on PON1 activity are minimal.

Toxicity Persistence in Runoff Water and Soil in Experimental Soybean Plots Following Chlorpyrifos Application

Toxicity persistence in runoff water and soil was studied in experimental soybean plots in successive runoff events produced by an irrigation system. Three chlorpyrifos applications throughout the growing period were assayed. Runoff and soil toxicity to the amphipod Hyalella curvispina and the fish Cnesterodon decemmaculatus was assessed. Toxicity persistence to H. curvispina was shorter in the early and midseason applications (23-28 and 21-69days in runoff and soil, respectively) and longer in the late application (more than 140days). The same trend was observed for C. decemmaculatus: 13days for early and 56 for the late application.

Microbial Biomass and Carbon Mineralization in Agricultural Soils as Affected by Pesticide Addition

A laboratory study was conducted with four pesticides, viz. a fungicide (carbendazim), two insecticides (chlorpyrifos and cartap hydrochloride) and an herbicide (pretilachlor) applied to a sandy clay loam soil at a field rate to determine their effect on microbial biomass carbon (MBC) and carbon mineralization (C(min)). The MBC content of soil increased with time up to 30days in cartap hydrochloride as well as chlorpyrifos treated soil. Thereafter, it decreased and reached close to the initial level by 90th day. However, in carbendazim treated soil, the MBC showed a decreasing trend up to 45days and subsequently increased up to 90days. In pretilachlor treated soil, MBC increased through the first 15days, and thereafter decreased to the initial level. Application of carbendazim, chlorpyrifos and cartap hydrochloride decreased C(min) for the first 30days and then increased afterwards, while pretilachlor treated soil showed an increasing trend.

Compatibility of Mesorhizobium sp. Cicer with seed treatment of fungicide and insecticide in chickpea

This investigation was undertaken to study the compatibility of Mesorhizobium sp. Cicer with captan (fungicide) and chlorpyrifos (insecticide) for growth, symbiotic parameters and yield in chickpea. In an in vitro experiment, a significant reduction in the number of viable mesorhizobia was observed in Mesorhizobium sp. Cicer treated chickpea seeds at the recommended doses of captan (3 g kg−1 seed) and chlorpyrifos (10 ml kg−1 seed) after 4 h storage at 4°C, and further reduction was seen after 8–16 h contact with Mesorhizobium. The results showed that captan was more toxic than chlorpyrifos. In field experiments, improved growth and symbiotic parameters (plant height, dry weight of shoot, nodulation, leghaemoglobin content, chlorophyll content and nitrogen content) and a reduction in per cent damaged by termites and diseases were observed in the Mesorhizobium alone treatment compared with the uninoculated control. Grain yield was increased significantly in treatments with Mesorhizobium alone or in a mixture with fungicide and insecticide (captan and chlorpyrifos) compared with the control treatment. It is evident that chemically treated seeds should always be sown as soon as possible after inoculation. Recommended rates of captan and chlorpyrifos application with Mesorhizobium inoculant as a seed treatment was innocuous to chickpea–Mesorhizobium symbiosis.

Pyroxsulam and Chlorpyrifos Applied the Same Day Injures Wheat

Field experiments were conducted in northwestern Kansas for two years to determine the effect of chlorpyrifos application timing on winter wheat response to pyroxsulam applied postemergence. Pyroxsulam at 18.4 g ai/ha was applied in spring when wheat was 10 to 15 cm tall. Chlorpyrifos at 260 g ai/ha was applied 3 or 7 days before, and 3 or 7 days after pyroxsulam application. Also a treatment of pyroxsulam and chlorpyrifos applied on the same day was included. When pyroxsulam and chlorpyrifos were applied on the same day, wheat leaf injury was greatest at 7 days after herbicide treatment (DAHT) (16%) and 14 DAHT (10 to 18%). This was 2 to 10 times higher than the injury caused by pyroxsulam applied alone. Same day application of pyroxsulam and chlorpyrifos also reduced plant height by 8% at 21 DAHT and delayed 50% heading by one day compared to pyroxsulam alone. Chlorpyrifos applied 3 to 7 days before or after pyroxsulam application caused similar or slightly higher leaf injury and growth reduction compared to pyroxsulam alone. Grain yields were not adversely affected by any treatment. To avoid crop injury, at least a 3-day interval between pyroxsulam and chlorpyrifos applications is desirable.

Risk assessment of chlorpyrifos on rice and cabbage in China

Chlorpyrifos is a widely used organophosphorus insecticide in agricultural pest control. To understand the residue behavior of chlorpyrifos and to evaluate the dietary risk of chlorpyrifos residue in food in China, a number of residue studies were conducted on rice and cabbage. The supervised trial median residues (STMRs) for rice and cabbage were less than 0.010 and 0.227mgkg−1, respectively. Only 7.4% and 13.3% of acceptable daily intake (ADI) (0–0.01mgkg−1bw) of chlorpyrifos is occupied by dietary daily intake to the Chinese adult and children, respectively, due to the consumption of rice and cabbage. These results on risk assessment were consistent with that of JMPR. Incorporation of market survey residue data gave a 5-fold reduction in the estimated exposures to chlorpyrifos. Concerning the acute exposure, the national estimated short-term intake (NESTI) represents 0.077% and 10.6% for rice and cabbage, respectively, of the acute reference dose (ARfD) (0–0.1mgkg−1bw). The application of chlorpyrifos at the recommended dose on rice and cabbage is unlikely to pose any public health issues if it is applied according to the good agricultural practices (GAPs) established by each country.

Differential sensitivity of plasma carboxylesterase-null mice to parathion, chlorpyrifos and chlorpyrifos oxon, but not to diazinon, dichlorvos, diisopropylfluorophosphate, cresyl saligenin phosphate, cyclosarin thiocholine, tabun thiocholine, and carbofuran

Mouse blood contains four esterases that detoxify organophosphorus compounds: carboxylesterase, butyrylcholinesterase, acetylcholinesterase, and paraoxonase-1. In contrast human blood contains the latter three enzymes but not carboxylesterase. Organophosphorus compound toxicity is due to inhibition of acetylcholinesterase. Symptoms of intoxication appear after approximately 50% of the acetylcholinesterase is inhibited. However, complete inhibition of carboxylesterase and butyrylcholinesterase has no known effect on an animal’s well being. Paraoxonase hydrolyzes organophosphorus compounds and is not inhibited by them. Our goal was to determine the effect of plasma carboxylesterase deficiency on response to sublethal doses of 10 organophosphorus toxicants and one carbamate pesticide. Homozygous plasma carboxylesterase deficient ES1−/− mice and wild-type littermates were observed for toxic signs and changes in body temperature after treatment with a single sublethal dose of toxicant. Inhibition of plasma acetylcholinesterase, butyrylcholinesterase, and plasma carboxylesterase was measured. It was found that wild-type mice were protected from the toxicity of 12.5mg/kg parathion applied subcutaneously. However, both genotypes responded similarly to paraoxon, cresyl saligenin phosphate, diisopropylfluorophosphate, diazinon, dichlorvos, cyclosarin thiocholine, tabun thiocholine, and carbofuran. An unexpected result was the finding that transdermal application of chlorpyrifos at 100mg/kg and chlorpyrifos oxon at 14mg/kg was lethal to wild-type but not to ES1−/− mice, showing that with this organochlorine, the presence of carboxylesterase was harmful rather than protective. It was concluded that carboxylesterase in mouse plasma protects from high toxicity agents, but the amount of carboxylesterase in plasma is too low to protect from low toxicity compounds that require high doses to inhibit acetylcholinesterase.

Assessing the impact of chlorpyrifos on growth, photosynthetic pigments and yield in Vigna radiata L. at different phenological stages

The application of an insecticide is a common practice in the cultivation of mungbean (Vigna radiata L.). It therefore seems important to test the changes that are occurring in this food crop under chlorpyrifos treatments in order to identify the extent to which it tolerates the insecticide application thereby making it an economical food crop. 20 day old seedlings were exposed to different concentrations ranging from 0 to 1.5 mM of chlorpyrifos through foliar spray in the field condition. The seedlings were uprooted for analyses and observed at the preflowering (5 days after treatment, DAT), flowering (10 DAT) and post-flowering (20 DAT) stages for various morphological parameters such as plant height, number of branches, leaves per plant, total leaf area, plant biomass and photosynthetic pigments namely Chlorophyll (Chl) a, Chl b, Total Chl, and Carotenoid (Car) content. Yield attributing characters like number of pods plant-1, number of seeds pod-1 and weight of 100 seeds were analyzed from both control and treated plants after physiological maturity. All the growth parameters, pigments’ activity and yield parameters increased at 0.3 mM insecticidal treatment, when compared with control. Further increase in insecticide level had a negative impact upon all parameters studied. The data suggests that the application of chlorpyrifos at lower concentration may be a useful tool to increase the seed quality as well as quantity in mungbean plant, apart from their insecticidal properties. Key words: Chlorophyll, insecticide, mungbean, stress.

A comparison of neurotoxicity in cerebellum produced by dermal application of chlorpyrifos in young and adult mice

Chlorpyrifos (CPF), an organophosphate pesticide inhibits acetylcholinesterase (AChE) and causes neuromuscular incoordination among children and elderly. The objectives of the present study were to compare the neurotoxic effects of dermal application of CPF on the cerebellum in the parameters of glial fibrillary acidic protein (GFAP) expression in young and adult mice and to correlate with the changes in acetylcholinesterase levels. Male Balb/c mice, 150days old (adult) and 18days old (young) were dermally applied with ½ LD(50) of CPF over the tails for 14days. Serum AChE concentration was estimated and GFAP immunostaining was performed on sagittal paraffin sections through the vermis of cerebellum. Although reduced in both age-groups exposed to CPF, percentage of reduction in serum AChE was more in adult compared to the young. Under GFAP immunostaining, brown colour fibres and glial cells were observed in cerebellar cortex and medulla in both the experimental groups. The mean GFAP-positive glial cell count in cerebellar medulla per mm(2) of section was significantly (p<0.05) increased in adult mice exposed to CPF when compared with age-matched control. In conclusion, this study confirmed that dermal exposure of CPF was able to exert neurotoxic effect in both young and adult mice. However, the quantitative results revealed that adult mice showed more GFAP expression in cerebellum when compared with the young, when exposed to CPF.