Monitoring of seasonal vegetables for pesticide residues

Dietary Predictors of Urinary Biomarkers of Pyrethroids in the General Population - A Scoping Review

BACKGROUND

Pyrethroid pesticides are ubiquitous environmental contaminants, contributing to chronic and potentially harmful exposure among the general population. Although studies have measured pesticide residues on agricultural products, the link between food intake and concentrations of pyrethroid biomarkers in urine remains unclear.

OBJECTIVE

This scoping review aims to analyze peer-reviewed publications investigating dietary predictors of pyrethroid exposure through urinary biomarkers. We assess existing evidence, identify research gaps, and highlight current limitations.

METHODS

We conducted a comprehensive search using PubMed and Google Scholar. Eligible studies examined associations between diets, food items or dietary components, and measured urinary pyrethroid biomarkers. No geographical restriction was applied to our search. Results were summarized in themes referring to study characteristics, relevant outcomes, biomarker measurement, dietary assessment and statistical analyses.

RESULTS

We identified 20 relevant articles. Most studies presented evidence on associations between the consumption of organic diets or food items and reduced concentrations of 3-phenobenzoic acid metabolites in urine. There was less evidence for diet affecting other pyrethroid-specific biomarkers. Dietary assessment methodologies and recall periods varied, as did the number and timing of urine collections. Many studies did not control for potential alternative pyrethroid sources, exposure to other pesticides, or demographic and socioeconomic characteristics.

CONCLUSION

Researchers should consider standardized dietary assessment, chemical analyses of foods consumed, adequate recall time, and food preparation methods. Consistency in biomarker measurement, including urine collection time and corrections for specific gravity or creatinine, is needed. Ensuring the validity of such studies also requires larger samples and appropriate control for confounders.

Dissipation and risk assessment of fluopyram and trifloxystrobin on onion by GC-MS/MS

The dissipation and risk assessment studies on fluopyram, trifloxystrobin and their metabolites were carried out on onion under field conditions after two treatments of fluopyram 250 g/L + trifloxystrobin 250 g/L SC @ 150 and 300 g a.i. ha^-1. The onion bulb samples were collected at 0, 3, 7, 14, and 21 days after second spray to study the pattern of dissipation using QuEChERS methodology for processing and analysis on GC-MS/MS. The total initial residues of fluopyram (fluopyram + fluopyram benzamide) in immature onion bulb were 2.14 and 4.93 mg kg^-1, at single and double dose, respectively. The residues of 0.02 and 0.06 mg kg^-1 persisted in the mature onion bulb collected at the harvest (30 days after treatment). The total initial residues of trifloxystrobin (trifloxystrobin + CGA 321113) in immature onion bulb were 0.65 and 1.97 mg kg^-1, at single and double dose, respectively, which reached < LOQ and 0.06 mg kg^-1 at the respective doses at the harvest time. Dissipation of fluopyram followed second-order kinetics with DT₅₀ values of 1.83 and 1.74 days, whereas trifloxystrobin followed first-order kinetics with DT₅₀ values of 4.73 and 4.78 days, at single and double dose respectively. Risk assessment in terms of hazard quotient was done to estimate the risk that can occur due to application of this combination pesticide. It was observed that even the spray at the double recommended dose could not have dietary risks on the consumers.

Antioxidant mediated protective effect of Bridelia tomentosa leaf extract against carbofuran induced oxidative hepatic toxicity

•

Bridelia tomentosa is a traditional medicinal plant that is used against colitis, traumatic injury, diarrhea, and diabetes.

•

Gallic acid, Tannic acid, salicylic acid, and naringin were isolated from the leaf of B. tomentosa for the first time.

•

B. tomentosa extract amended serum biochemical markers, MDA levels, and improved the levels of hepatic antioxidant enzymes.

•

Phenolic and flavonoid compounds of the B. tomentosa can be used as nutraceuticals for treating oxidative hepatic ailments.

Bridelia tomentosa (B. tomentosa) is a traditional medicinal plant for treating diverse ailments. Hence, we designed our study to scrutinize the protective effect of the methanol extract of B. tomentosa leaf (BTL) against carbofuran-induced oxidative stress-mediated hepato-toxicity in Sprague-Dawley rats for the first time, along with the identification and quantification of phenolic acids and flavonoids by high-performance liquid chromatography (HPLC) and evaluation of antioxidant and antiradical activities of this extract. HPLC analysis confirmed the existence of tannic acid, gallic acid, salicylic acid, and naringin in B. tomentosa leaf extract which showed in-vitro antioxidant potentialities with DPPH, nitric oxide, hydrogen peroxide, and hydroxyl radical scavenging properties. Co-administration of B. tomentosa leaf extract with carbofuran showed dose-dependent significant protective effects of hepatic toxicity on serum markers such as alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, γ-glutamyl-transferase, lactate dehydrogenase, total bilirubin, total protein, albumin, globulin, lipid profile, urea, uric acid, and creatinine. Carbofuran intoxication also revealed an upsurge in malondialdehyde (MDA) and a decline in cellular endogenous antioxidant enzyme levels in rats compared with the control group. However, B. tomentosa leaf extract co-treatment increased the levels of hepatic antioxidant enzymes, such as superoxide dismutase, catalase, and glutathione peroxidase, and amended the MDA level. Similarly, histopathological evaluation further assured that BTL could keep the hepatocyte from carbofuran-induced damage. Therefore, all of our findings may conclude that the phenolic acids and flavonoids of B. tomentosa leaf extract are responsible to neutralize the toxic free radical-mediated oxidative hepatic damages.

Monitoring of pesticide residues from fish feed, fish and vegetables in Bangladesh by GC-MS using the QuEChERS method

The use of pesticides in agricultural sectors is rising due to the growing demand for food in the world, but the presence of pesticide residues in agricultural commodities has become a major health concern for consumers and is associated with problems of food safety. Thus, the present study determined pesticide residues (17 organochlorine, 5 pyrethroid and 3 organophosphate) in 77 fish feed, 112 fish and 135 vegetables samples (total of 324) from the different locations in Bangladesh, using quick easy cheap effective rugged and safe (QuEChERS) extraction followed by gas chromatography-mass spectrometry (GC-MS) analysis. The 77 fish feed samples analyzed with this method appeared to be free of pyrethroid pesticide residues. Organochlorine pesticide residues aldrin (0.03 ± 0.01 mg/kg) and pyrethroid pesticide residues permethrin (0.08 ± 0.01 mg/kg) were detected in fish samples of catla (Catla catla) from Rajshahi Durgapur and bata (Labeo bata) from Satkhira Kaligonj, respectively. Among 135 vegetable samples (country bean, green chili, tomato, eggplants and red amaranth), 27.4% were found positive for organophosphate pesticide residues of which 89.2% exceeded maximum residue limits (MRLs) set by the Codex Alimentarius Commission. The study revealed that few fish (catla and bata) but the majority of vegetable samples tested positive for pesticide residues exceeding MRLs. Finally, the study suggests that an effective management strategy is needed for strict regulation and regular monitoring of pesticides in fish feed, fish and vegetables to make aware the farmers and consumers about the harmful effect of pesticides on human health.

Pesticide residue levels in vegetables and surface waters at the Central Rift Valley (CRV) of Ethiopia

Seven pesticides, profenofos, metalaxyl, λ-cyhalothrin, 4,4'-DDT, 4,4'-DDE, and α- and β-endosulfan, were determined in vegetables (tomato, onion) from 20 locations and surface waters from 12 locations in the Central Rift Valley (CRV) of Ethiopia. Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) and solid phase extraction (SPE) methods were used for the vegetables and water, respectively. In 2.5% of the tomato samples, profenofos was detected above European maximum residue limits (MRLs), in 12.5% of the samples metalaxyl, and in 2.5% α- and β-endosulfan. In 5% of the onion samples, profenofos was detected above European MRLs, in 7.5% of the onion samples metalaxyl, and in 5% λ-cyhalothrin. In surface water, profenofos was detected at the highest concentration of 2300 μg/L in the Bulbula River, 890 μg/L near the agricultural land north of Lake Ziway (ANLZ-1), 1700 μg/L in the floriculture effluent (FE-1), and 900 μg/L in tap water at the Batu Drinking Water (BDW) supply. These results show that the levels of pesticides are in several cases substantially elevated, and emphasize the need of regular pesticide monitoring programs for surface waters and vegetables in the Ethiopian CRV.

Deregulation of hepatic lipid metabolism associated with insulin resistance in rats subjected to chronic monocrotophos exposure

In our previous study, we demonstrated the potential of monocrotophos (MCP), an organophosphorus insecticide (OPI), to induce glucose intolerance, insulin resistance (IR), and dyslipidemia with hyperinsulinemia in rats after chronic exposure. As hyperinsulinemia is likely to exert an impact on hepatic lipid metabolism, we carried out this study to establish the effect of chronic MCP exposure (0.9 and 1.8 mg/kg/day for 180 days) on hepatic lipid metabolism in rats. The state of IR induced by MCP in rats was associated with an increase in the liver lipid content (triglyceride and cholesterol) and expression levels of sterol regulatory element-binding proteins, PPARγ, acetyl-CoA carboxylase, and fatty acid synthase in the liver. Similarly, activities of key enzymes (acetyl-COA carboxylase, fatty acid synthase, lipin 1, malic enzyme, glucose-6-phosphate dehydrogenase, and glycerol-3-phosphate dehydrogenase), which regulate lipogenesis, were enhanced in livers of pesticide-treated rats. A strong correlation was observed between insulin levels, hepatic lipid content, and plasma lipid profile in treated rats. Our study suggests that long-term exposure to OPIs not only has a propensity to induce a state of hyperinsulinemic IR, but it is also associated with augmented hepatic lipogenesis, which may explain dyslipidemia induced by chronic exposure to MCP.

Pesticide Residues in Eggplant Fruit from Khartoum State, Sudan

BACKGROUND

Eggplant is a popular food item in Sudan, however pesticides are heavily used.

OBJECTIVE

To investigate the presence of pesticide residues in fresh eggplants in Khartoum State, Sudan.

METHODS

Eggplant fruit samples from three different regions in Khartoum State (central vegetable market, east Nile farms, and west Nile farms) were analyzed for residues of commonly used pesticides. Pesticide residues were analyzed by gas chromatography coupled with mass spectrometry and results were expressed in μg/kg fruit.

RESULTS

Out of the 11 active ingredients analyzed, residues were identified for four pesticides (imidacloprid, dimethoate, endosulfan (α and β isomers) and 2, 4-D). Levels of omethoate, diazinon, malathion, chlorpyrifos, atrazine, and pendimethalin were below the detection limits.

CONCLUSIONS

Residues of four insecticides out of the 11 analyzed (imidacloprid, dimethoate, endosulfan (α, β isomers), and 2, 4-D) were detected in the current study. The health implications of these violative levels should be regularly observed along with strict enforcement of laws and regulations coupled with agricultural extension interventions.

COMPETING INTERESTS

The authors declare no competing financial interests.

Health risk assessment of pesticide residues in fruits and vegetables from farms and markets of Western Indian Himalayan region

The extensive use of pesticides in agriculture has become a very common practice in developing countries like India. Consequently, the increased concentration of residues of these hazardous pesticides in fruits and vegetables is manifested. The study aimed to assess the health hazards associated with the presence of pesticide residues in fruits and vegetables sampled from farms and markets of Kinnaur district of Himachal Pradesh (India). Residues of predominant pesticides used in the region, belonging to the group of organophosphates, pyrethroid and phthalimide, were analysed using gas chromatograph quadrupole mass spectrometer (GC-MS/MS). The pesticide extraction from the matrix was done following the modified QuEChERS method. Results indicated varying concentrations of pesticide residue in market and farm samples with farm samples more contaminated than market samples. Chronic health hazards prediction indicated that organophosphorus groups (methyl parathion and triazophos) posed health risk to children in the study area.

Assessing and Reporting Household Chemicals as a Novel Tool to Mitigate Pesticide Residues in Spinach (Spinacia oleracea)

Non-selective use of pesticide to increase productivity leaves residues on crops. These pesticides after consumption have a detrimental effect on human health and their intake can lead to various diseases such as kidney damage, neurological disorders, cardiovascular diseases, circulatory and reproductive problems. The recent study was designed to assess the effects of household processing treatments such as acidic solutions (acidic acid and citric acid), alkaline solutions (sodium chloride and sodium carbonate) and biological solutions (radish, ginger, garlic, and lemon extracts) were evaluated for their efficiency for removal of pesticides in spinach by gas chromatography with electron capture detector (GC-ECD). The results showed that pesticide residues were sharply reduced when spinach was exposed to washing treatments. The results showed that the greatest reduction of deltamethrin, cypermethrin, chlorpyrifos and endosulfan with 10% acetic acid was (79.68 ± 0.81%), (89.99 ± 0.12%), (94.21 ± 0.02%) and (70.32 ± 0.25%), respectively of tested washing solutions. The acidic solutions were more effective than alkaline and biological extracts in the removal of pesticide residues. The average reduction in various washing solutions ranged from 10.21 to 79.68%, 22.60 to 89.48%, 22.95 to 94-21% and 11.24–70.32% for the removal of deltamethrin, cypermethrin, chlorpyrifos, and endosulfan, respectively.

Differences in the uptake and bioconcentration of dichlorodiphenyltrichloroethane by eight vegetable cultivars and their health risk assessments

Dichlorodiphenyltrichloroethane (DDT) is not easily degraded in soils, which will pose a threat to human health. We investigated the differences of eight vegetables' capacity to take up DDT, removing DDT from soil, and tolerating DDT (monitoring the responses of growth, root morphology and photosynthesis of vegetables to DDT). These vegetables included Chinese mustard (two genotypes, B.jf and B,jm), napa cabbage (two genotypes, B.coz and B.coc) and Bok choy (four genotypes, B.cz, B.cq, B.cs and B.chg). The results demonstrated that 5 mg kg^-1 DDT did not display significant effects on the growth of most vegetables in this study. As compared to the control, 5 mg kg^-1 DDT significantly increased the shoot and root biomass, the fine root numbers, and the fine root ratio for the genotype of B.chg. However, 5 mg kg^-1 DDT exposure showed a negative effect on the shoot growth of two genotypes of napa cabbage. In general, 5 mg kg^-1 DDT did not significantly affect the photosynthesis and root morphology of most vegetables in this study. Consuming these vegetables had a low non-cancer health risk, but showed a high cancer health risk. In addition, among the eight vegetables, B.chg accumulated less DDT in the edible parts and had low values of HR_non-cancer and HR_cancer for consuming these vegetables containing DDT. Planting these vegetables might promote the degradation of DDT reducing its residual amount in soil.

First report on organochlorine pesticides in water in a highly productive agro-industrial basin of the Central Valley, Chile

The Ñuble River flows through an agricultural area in the central zone of Chile in which different types of fruits are grown. The objective of this study was to identify the levels and source of organochlorine pesticides (OCPs) in the surface waters of the Ñuble River. Surface water samples were collected at 10 sampling points and analyzed for 19 organochlorine pesticides during the dry (spring-summer) and wet (autumn-winter) periods of 2013 and 2014. The results revealed that concentrations of total OCPs in surface waters ranged from 0.12 to 26.28 ng/l. Endosulfan and lindane were the main OCPs in the water. The maximum OCP levels were found in the dry period, while significantly lower concentrations were recorded in the wet period. This indicates that patterns of OCPs have varied in the last 10 years as this study found low concentrations of DDT and metabolites but significantly increased concentrations of α-endosulfan. Given the fact that OCPs were withdrawn from agricultural used many years ago, their presence indicates that they may be still in use clandestinely. Findings of significant concentrations of endosulfan and lindane in this study lead to the conclusion that the chemical fallow practices contribute to runoff into the river and surface water infiltration into groundwater. Because no studies have previously measured OCP levels in agricultural basins in Chile, this study is an important contribution to the knowledge of organochlorine contaminants present in surface water in Chile.

Evaluation of various soaking agents as a novel tool for pesticide residues mitigation from cauliflower (Brassica oleracea var. botrytis)

The increasing use of pesticides for boosting the yield of agricultural crops also impart toxic residues which ultimately extend to numerous physiological disorders upon consumption. The present study was designed as an effort to assess the reduction potential of various chemical solutions and to minimize the pesticide residues in cauliflower (Brassica oleracea var. botrytis). The samples were soaked in various solutions along with tap water to mitigate pesticide residues. Afterwards, the extracted supernatant was passed through column containing anhydrous sodium sulfate trailed by activated carbon for clean-up. Eluents were first evaporated and then completely dried under gentle stream of Nitrogen. Finally, the residues were determined using gas chromatography equipped with electron capture detector (GC-ECD). Results revealed the highest reduction of endosulfan, bifenthrin and cypermethrin residues with acetic acid (10 %) was 1.133 ± 0.007 (41 %), 0.870 ± 0.022 (60 %) and 0.403 ± 0.003 (75 %), respectively among the tested solutions. However, simple tap water treatment also resulted in 0.990 ± 0.02 (12 %), 1.323 ± 0.015 (14 %) and 1.274 ± 0.002 (21 %) elimination of endosulfan, bifenthrin and cypermethrin residues, respectively. Moreover, among various solutions, acetic acid depicted maximum reduction potential followed by citric acid, hydrogen peroxide, sodium chloride and sodium carbonate solutions. The percent reduction by various solutions ranged from 12 to 41, 14 to 60 and 21 to 75 % for the elimination of endosulfan, bifenthrin and cypermethrin residues, respectively.

Curcumin Mediated Attenuation of Carbofuran Induced Oxidative Stress in Rat Brain

The indiscriminate use of carbofuran to improve crop productivity causes adverse effects in nontargets including mammalian systems. The objective of this study was to evaluate carbofuran induced oxidative stress in rat brain stem and its attenuation by curcumin, a herbal product. Out of 6 groups of rats, 2 groups received two different doses of carbofuran, that is, 15 and 30% of LD₅₀, respectively, for 30 days. Out of these, 2 groups receiving same doses of carbofuran were pretreated with curcumin (100 mg/kg body weight). The levels of antioxidants, TBARS, GSH, SOD, catalase, and GST were determined in rat brain stem. The 2 remaining groups served as placebo and curcumin treated, respectively. The data suggested that carbofuran at different doses caused significant alterations in the levels of TBARS and GSH in dose dependent manner. The TBARS and GSH contents were elevated. The activities of SOD, catalase, and GST were significantly inhibited at both doses of carbofuran. The ratio of P/A was also found to be sharply increased. The pretreatment of curcumin exhibited significant protection from carbofuran induced toxicity. The results suggested that carbofuran at sublethal doses was able to induce oxidative stress in rat brain which could be attenuated by curcumin.

Occurrence and spatial distribution of pesticide residues in butter and ghee (clarified butter fat) in Punjab (India)

The present study was undertaken to monitor organochlorine, organophosphate, and synthetic pyrethroid pesticide residues in butter (n = 55) and ghee (n = 56) samples collected from three different regions of Punjab. The estimation of pesticide residues was done by multiple residue analytical technique using gas chromatography equipped with GC-ECD and GC-FTD. The confirmation of residues was done on gas chromatography mass spectrometry in both selective ion monitoring (SIM) and scan mode. Results indicated the presence of hexacholorocyclohexane (HCH) and p,p' DDE as predominant contaminant in both butter and ghee. Residues of HCH were detected in 25 and 23% samples of butter and ghee, respectively, while residues of p,p' DDE were recorded in 29 and 25% of butter and ghee samples, respectively. None of the butter and ghee sample violated the MRL values of 200 ng g(-1) for HCH and 1250 ng g(-1) for dichorodiphenyl tricholorethane (DDT). The presence of endosulfan, cypermethrin, fenvalerate, deltamethrin, and chlorpyrifos were observed in a few butter and ghee samples at traces. The spatial variation for comparative occurrence of pesticide residues indicated higher levels in the south-western region of Punjab. Additionally, the temporal variation indicated the significant reduction of HCH and DDT levels in butter and ghee in Punjab.

A novel pilin subunit from Xenorhabdus nematophila, an insect pathogen, confers pest resistance in tobacco and tomato

KEY MESSAGE

Overexpression of insecticidal pilin subunit from Xenorhabdus nematophila protects transgenic tobacco and tomato plants against Helicoverpa armigera. Xenorhabdus nematophila is a pathogenic bacterium producing toxins that kill the larval host. Previously, we characterized a pilin subunit of X. nematophila which was found to be a pore-forming toxin and cytotoxic to the larval hemocytes of Helicoverpa armigera by causing agglutination and lysis of the cells. In the present study, we report the efficacy of the insecticidal pilin subunit expressed in transgenic tobacco and tomato plants for control against H. armigera. A 537 bp mrxA gene encoding the 17 kDa insecticidal pilin subunit was transferred into the genome of tobacco and tomato, respectively, via Agrobacterium-mediated transformation. The stable integration of the 537 bp mrxA gene in the transgenic plants was confirmed by Southern blot analysis and expression of mrxA gene was confirmed by RT-PCR and Western blot analyses. The transgenic plants appeared healthy and phenotypically normal but proved toxic to the insects in insect bioassays, showing 100% insect mortality and reduced damage of the transgenic plants. Based on these observations, it is suggested that pilin subunit can be used as a potential candidate for control of H. armigera and may open new strategies for pest control in agricultural plants.

Health risk assessment of organochlorine pesticide exposure through dietary intake of vegetables grown in the periurban sites of Delhi, India

The study investigated the levels of organochlorine pesticides (OCPs) in different types of vegetables grown in periurban area of National Capital Region (NCR), India. Vegetable sampling was carried out in winter and summer season of 2012. A total of 20 different OCPs were determined using gas chromatography (GC) assembled with electron capture detector (ECD). Obtained results showed that average levels of ∑(20)OCP ranged from 83.8 ± 25.5 ng g(-1) in smooth gourd to 222.4 ± 90.0 ng g(-1) in cauliflower. The mean concentrations of different OCPs were observed in order of ∑HCH > ∑CHLs > drins > ∑endosulfan > ∑DDT in all vegetables except in brinjal and smooth gourd. Most of the OCP residues recorded in vegetable samples exceeded the maximum residue levels (MRLs) set by international and national regulatory agencies. Health risk assessment suggests that daily dietary OCP exposure via vegetable consumption was higher for children (mean value 4.25E-05) than adults (mean value 2.19E-05). The hazard quotient (HQ) and lifetime cancer risk (LCR) estimated from dietary exposure of these vegetables were above the acceptable limit and can be considered as a serious concern for Delhi population.

Organophosphorus insecticide, monocrotophos, possesses the propensity to induce insulin resistance in rats on chronic exposure

BACKGROUND

Our earlier studies had shown that monocrotophos (MCP), an organophosphorus insecticide (OPI), has the propensity to augment the secondary complications associated with type-1 diabetes. The present study investigates whether rats exposed for prolonged periods to monocrotophos would develop insulin resistance mediated by alteration in glucose homeostasis.

METHODS

Male rats were administered sublethal doses of monocrotophos daily for 180 days. Interim blood samples were collected to measure alteration in blood glucose and lipid profile. Rats were also subjected to glucose and insulin tolerance test and fasting blood glucose and insulin levels were measured to calculate insulin resistance by HOMA-IR method. After 180 days, the rats were also evaluated for pancreatic histology and activities of hepatic gluconeogenetic enzymes.

RESULTS

Monocrotophos elicited a gradual and sustained increase in blood glucose and insulin resistance in rats with concomitant glucose intolerance and reduced insulin sensitivity. MCP exposure was also associated with increase in weights of key white adipose pads, activities of gluconeogenesis enzymes and increase in pancreatic islet diameter, all of which led to hyperglycemia, hyperinsulinemia and dyslipidaemia.

CONCLUSION

Long-term exposure of rats to MCP resulted in glucose intolerance with hyperinsulinemia, a hallmark of insulin resistance. Our data suggest that chronic exposure to low doses of monocrotophos, might lead to development of insulin resistance by altering lipid profile and glucose homeostasis.

Sublethal toxicity of commercial formulations of deltamethrin and permethrin on selected biochemical constituents and enzyme activities in liver and muscle tissues of Anabas testudineus

The freshwater fish Anabas testudineus was exposed for 21 days to two commercial formulations of synthetic pyrethroids deltamethrin and permethrin at sublethal concentrations of 0.007 and 0.0007 mg L(-1), and 0.093 and 0.0093 mg L(-1), that represented 10% and 1%, respectively, of the 96 h LC50 of these two pesticides for this fish. The glycogen, protein and lactic acid contents, along with succinate dehydrogenase (SDH), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) enzyme activities in liver and muscle tissues of control and pesticide-exposed fish were estimated. When compared with those of control fish, significant depletion of glycogen content was observed in liver, and that of protein in muscle tissue of fish treated with both the pesticides at their higher as well as lower concentrations. Lactic acid reduction was significant only in fish muscle treated with deltamethrin. SDH level was reduced significantly in both liver and muscle tissues except in fish exposed to 0.0093 mg L(-1) permethrin. AST level was reduced significantly in liver and muscle tissues and ALT in muscle tissue of deltamethrin treated fish only. It is concluded that deltamethrin, a type-II pyrethroid, is more toxic to fish than the type-I pyrethroid permethrin and is capable of rendering toxicity at a dose as low as 1% of its LC50 value.

Determination of carbamate and organophosphorus pesticides in vegetable samples and the efficiency of gamma-radiation in their removal

In the present study, the residual pesticide levels were determined in eggplants (Solanum melongena) (n = 16), purchased from four different markets in Dhaka, Bangladesh. The carbamate and organophosphorus pesticide residual levels were determined by high performance liquid chromatography (HPLC), and the efficiency of gamma radiation on pesticide removal in three different types of vegetables was also studied. Many (50%) of the samples contained pesticides, and three samples had residual levels above the maximum residue levels determined by the World Health Organisation. Three carbamates (carbaryl, carbofuran, and pirimicarb) and six organophosphates (phenthoate, diazinon, parathion, dimethoate, phosphamidon, and pirimiphos-methyl) were detected in eggplant samples; the highest carbofuran level detected was 1.86 mg/kg, while phenthoate was detected at 0.311 mg/kg. Gamma radiation decreased pesticide levels proportionately with increasing radiation doses. Diazinon, chlorpyrifos, and phosphamidon were reduced by 40–48%, 35–43%, and 30–45%, respectively, when a radiation strength of 0.5 kGy was utilized. However, when the radiation dose was increased to 1.0 kGy, the levels of the pesticides were reduced to 85–90%, 80–91%, and 90–95%, respectively. In summary, our study revealed that pesticide residues are present at high amounts in vegetable samples and that gamma radiation at 1.0 kGy can remove 80–95% of some pesticides.

Assessment of dietary intakes of nineteen pesticide residues among five socioeconomic sections of Hyderabad--a total diet study approach

Total diet study approach was used to assess the dietary intakes of pesticide residues among the select population in Hyderabad. When assessed by a food frequency questionnaire, it was found that the food intakes varied among five socioeconomic sections (SES). Therefore, we intended to compare the intakes of pesticide residues through these foods among the five SES. A total of 195 foods from different markets were collected and analyzed for 19 pesticides. The residues were analyzed with a gas chromatograph and were confirmed with mass spectrometry. About 51 % of the samples were detected with one or more residues. Thirteen out of the 19 residues were present in levels above detection limits in various concentrations. The median concentrations of the residues in all the samples tested, ranged from 0.00010 to 0.33 mg/kg. Highest median concentration was for β-HCH in water samples. Exposures to all the residues were below the respective ADIs at both mean and 95th percentile levels of food intakes with highest estimated dietary intakes (EDIs) of β-HCH in both the cases. The EDIs of β-HCH were the highest among all the residues at both the intake levels among all the SES. The EDIs of β-HCH were significantly higher in lower SES than higher SES possibly due to the consumption of rice cooked in water contaminated with β-HCH. EDIs for other residues did not differ significantly among the five SES.

Effect of fruit and vegetable processing on reduction of synthetic pyrethroid residues

In this review, we emphasize that the advantages associated with applying pesticides to enhance agricultural productivity must be weighed against the possible health hazards arising from the appearance of toxic pesticide residues in food. First and foremost, pesticides should be handled and applied in compliance with good agricultural practices to minimize environmental or food commodity contamination.In developing countries, good agricultural practices are not fully abided by.When vegetables are produced in such countries, pesticides are applied or prospectively applied at each growth stage of the crop. Hence, contamination of vegetables and other food commodities occur. It is well known that processing of food derived from pesticide treated crop commodities can serve to reduce residues that reach consumers. Food safety can therefore partially be enhanced by employing suitable food processing techniques and appropriate storage periods, even in developing countries. Even common and simple household processing techniques for certain foods acquire significance as means to reduce the intake of harmful pesticide food residues.Pesticide residue levels in post-harvest raw agricultural commodities (RAC) are affected by the storage, handling and the processing steps they pass through, while being prepared for human consumption. The review of cogent literature presented in this article demonstrated differences among the pyrethroid insecticide residues present on or in foods, depending on how the RAC from which they came were processed for consumption. Peeling vegetables or fruit reduced pyrethroid residues the most (60-100% ), and juicing was nearly as effective in reducing residues (70-100% ). The least reduction occurred for foodstuffs that were only washed with tap water (I 0-70% ). Washing RACs with saline water and detergent was more effective(34-60%) in reducing residues than was simple washing under tap water. Freezing is also effective in reducing residue levels and achieved reductions between 24% and 94%. Cooking of food products eliminated 75-98% of the pesticide residues present, so was also relatively effective. When foods were cooked in oils, however,reductions in pesticide residues were less (45%).

Pesticide residues in human breast milk: risk assessment for infants from Punjab, India

Punjab state in India is an agrarian society, where agriculture is the lifeline of farming community. To keep pace with increasing demands of food for growing population the indiscriminate use of pesticides has led to the contamination of environment and food commodities in this region. Analysis of human breast milk samples (n=53) for pesticide residues revealed the presence of β-, γ-HCH, p,p' DDD, p,p' DDE, p,p' DDT and endrin with mean concentration of 97.9, 101.7, 239.8, 1574.1, 100.3 and 90.7 ng g(-1) lipid wt., respectively. In addition, occurrence of β-endosulfan, endosulfan sulphate, cypermethrin and chlorpyrifos in this study have also been reported for the first time in human breast milk in Punjab, India. With increase in parity, HCH and DDT residue burden in donor's milk decreased. Although levels of HCH and DDT residues in breast milk samples have decreased significantly, yet estimated daily intake values for DDT are higher than the FAO/WHO permissible tolerable daily intake values for few infants.

Occurrence of insecticide residues in selected crops and natural resources

Pesticide residue monitoring was taken up at Kothapally and Enkepally villages of Ranga Reddy district, Andhra Pradesh in food crops (rice, maize, pigeonpea), vegetables (tomato and brinjal), cotton besides soil and water during 2008-2009 seasons. Of the 80 food crop and cotton samples, only two rice grain samples (3 %) showed beta endosulfan residues and two (3 %) out of 80 soil samples of food crops and cotton showed alpha and beta endosulfan residues. Out of 75 tomato samples, 26 (35 %) were contaminated and 4 % had residues above maximum residue limit (MRLs). Out of the 50 soil samples from tomato fields, 13 (26 %) contained residues. Among the 80 brinjal samples, 46 (56 %) contained residues and 4 % of samples had residues above MRLs. Only 13 % of the soil samples from brinjal fields were contaminated. Water samples found free from residues. In general the incidence of residues was below MRL in food crops.

Monitoring of pesticide residues in market basket samples of vegetable from Lucknow City, India: QuEChERS method

The study was conducted on 20 vegetables including leafy, root, modified stem, and fruity vegetables like bitter gourd, jack fruit, french-bean, onion, colocassia, pointed gourd, capsicum, spinach, potato, fenugreek seeds, carrot, radish, cucumber, beetroot, brinjal, cauliflower, cabbage, tomato, okra, and bottle gourd. Forty-eight pesticides including 13 organochlorines (OCs), 17 organophosphates (OPs), 10 synthetic pyrethriods (SPs), and eight herbicides (H) pesticides were analyzed. A total number of 60 samples, each in triplicates, were analyzed using Quick, Easy, Cheap, Effective, Rugged, and Safe method. The quantification was done by GC-ECD/NPD. The recovery varies from 70.22% to 96.32% with relative standard deviation (RSD) of 15%. However the limit of detection ranged from 0.001-0.009 mg kg(-1)for OCs, SPs, OPs, and H, respectively. Twenty-three pesticides were detected from total 48 analyzed pesticides in the samples with the range of 0.005-12.35 mg kg(-1). The detected pesticides were: Σ-HCH, Dicofol, Σ-Endosulfan, Fenpropathrin, Permethrin-II, β-cyfluthrin-II, Fenvalerate-I, Dichlorvos, Dimethoate, Diazinon, Malathion, Chlorofenvinfos, Anilophos, and Dimethachlor. In some vegetables like radish, cucumber, cauliflower, cabbage, and okra, the detected pesticides (Σ-HCH, Permethrin-II, Dichlorvos, and Chlorofenvinfos) were above maximum residues limit (MRL) (PFA 1954). However, in other vegetables the level of pesticide residues was either below detection limit or MRL.

Monitoring of pesticide residues in vegetarian diet

Samples (28) of complete vegetarian diet consumed from morning till night i.e. tea, milk, breakfast, lunch, snacks, dinner, sweet dish etc. were collected from homes, hostels and hotels periodically from Hisar and analysed for detecting the residues of organochlorine, synthetic pyrethriod, organophosphate and carbamate insecticides. The estimation was carried out by using multi-residue analytical technique employing gas chromatograph (GC)-electron capture detector and GC-nitrogen phosphorous detector systems equipped with capillary columns. The whole diet sample was macerated in a mixer grinder and a representative sample in duplicate was analyzed for residues keeping the average daily diet of an adult to be 1,300 g. On comparing the data, it was found that actual daily intake (microgram/person/day) of lindane in two and endosulfan in four samples exceeded the acceptable daily intake. Residues of other pesticides in all the diet samples were lower than the acceptable daily intake (ADI) of the respective pesticides. The study concluded that although all the diet samples were found contaminated with one or the other pesticide, the actual daily intake of only a few pesticides was higher than their respective ADI. More extensive study covering other localities of Haryana has been suggested to know the overall scenario of contamination of vegetarian diet.

Carbofuran-Induced Oxidative Stress in Mammalian Brain

Chronic exposure to carbofuran, a carbamate pesticide, via oral administration has been reported to generate reactive oxygen species (ROS) in rat brain. However, information regarding the effect of short-term intraperitoneal (i.p.) carbofuran intoxication on oxidative stress is lacking. In the present study, the effect of carbofuran on oxidative indices in brain of Wistar rats has been determined by exposing the animals to three subacute concentrations (0.2, 0.4 and 0.8 mg/kg body weight) equivalent to 10, 20, and 40%, respectively, of its LD50 (i.p.) for 24 h. Rat liver has been used as a positive control. The results demonstrated that carbofuran treatment at the 3 concentrations tested caused significant increase in lipid peroxidation (LPO) by 12.50, 34.38, and 59.38%, respectively. The increased oxidative stress at same pesticide concentrations significantly induced activities of antioxidant enzymes such as superoxide dismutase (SOD) and catalase in rat brain; the impact on catalase being more marked only at high-pesticide doses (0.4 and 0.8 mg/kg body weight). Carbofuran also caused reduction in protein content of rat tissues tested. Rat brain was more severely affected by carbofuran than liver. The results clearly demonstrated that i.p. administration of carbofuran accelerated oxidative stress in rat brain in a dose-dependent manner.

Determination of phoxim residues in eggs by using high-performance liquid chromatography diode array detection after treatment of stocked housing facilities for the poultry red mite (Dermanyssus gallinae)

The poultry red mite Dermanyssus gallinae is the most important ectoparasite of poultry in several European countries. Phoxim is a well-known antiparasitic agent in wide use. Initial studies indicated that this compound could successfully be applied to eliminate D. gallinae in egg-laying birds and in henhouses by treating the cages and the equipment with it. In order to investigate whether phoxim residues are present in eggs from laying hens, we developed a selective and sensitive high-performance liquid chromatography method employing a simple water/acetonitrile gradient system. The amount of phoxim was determined by UV detection at 281 nm, and the presence of the residue was confirmed by diode array detection. The eggs were homogenized for sample pretreatment and extracted with acetonitrile and partitioned with n-hexane. The acetonitrile extract was further purified with silica gel column chromatography. Recovery rates (performed at the 5-120 microg kg(-1) level) were in the range of 86.0-92.1% with relative standard deviations between 3.1% and 16.3%. Based on a signal to noise ratio of 3, the limit of detection of the assay was approximately 2 microg kg(-1). The day-to-day variation in the concentration of phoxim in four contaminated eggs (5.7-51.6 microg kg(-1)) was generally less than 20%. The decision limit (CCalpha) and the detection capability (CCbeta) were 62.0 and 68.7 microg kg(-1), respectively. The applicability of the method was demonstrated in eggs from three clinical trials and from a field study. In these investigations, all animals were kept in conventional battery cages. No sample was found containing more than the maximum residue level of 60 microg kg(-1) for phoxim in eggs as given in Annex I of Council Regulation (EEC) No. 2377/90.

Monitoring of pesticide residues in fruits

Fruit samples of ber, grapes and guava analysed for pesticide residues employing multiresidue analysis by gas liquid chromatography equipped with ECD and NPD detectors and capillary columns showed contamination with organochlorine, synthetic pyrethroid and organophosphate insecticides. Among organochlorines, HCH, DDT and endosulfan were detected in almost all the samples. Residues of HCH and DDT were maximum in ber followed by grapes and guava where as of endosulfan were maximum in guava followed by grapes and ber. All the fruit samples showed the presence of residues with one or the other group of pesticides. Residues of none of the pesticides exceeded the MRL values in any sample. On the basis of these studies, it is suggested that monitoring studies should be extended to other fruits grown in different agro climatic regions which may serve as basis for future policy in chemical use.

Characterization of the Thermal Decomposition and Polymerization of Arprocarb Using Pyrolysis-GC-MS

Arprocarb is a carbamate type insecticide used to control cockroaches, flies, mosquitoes, and is a lawn and turf insect growth regulator. In order to evaluate the effects of the thermal behavior of arprocarb on its bioactivity or the environment, its thermal decomposition and polymerization were characterized using pyrolysis-GC-MS (Py-GC-MS). Arprocarb was pyrolysed at 450 degrees C, 600 degrees C, 750 degrees C, and 900 degrees C, respectively. In all 71 components were determined. It was found that arprocarb was obviously decomposed when the temperature was lower (450 approximately 750 degrees qC), and a large number of mono- and polycyclic aromatic hydrocarbons (PAHs) were produced at higher temperatures (750 approximately 900 degrees C). Furthermore, the variety of the representative compounds versus the temperature was reported. The research results can provide useful information for the understanding of the thermal behavior of arprocarb.

Carbofuran-induced neurochemical and neurobehavioral alterations in rats: attenuation by N-acetylcysteine

Carbofuran, a widely used carbamate pesticide, has been reported to cause neurotoxicity. However, the underlying mechanisms involved in carbofuran neurotoxicity are not well understood. The present study was envisaged to investigate the possible role of oxidative stress in carbofuran neurotoxicity and to evaluate the protective effects of N-acetylcysteine (NAC). Acetylcholinesterase activity was significantly inhibited in all the regions of brain after carbofuran exposure (1 mg/kg body weight, orally, for 28 days). NAC, on the other hand, was found to partially restore the activity of acetylcholinesterase in carbofuran treated animals. Carbofuran exposure resulted in increased lipid peroxidation (LPO) in brain regions accompanied by decreased levels of glutathione. NAC administration to the carbofuran exposed animals lowered LPO along with partial repletion in glutathione levels. Concomitantly, the activities of superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase were significantly decreased after carbofuran exposure, while no significant change in the activity of glutathione-S-transferase was observed. NAC treatment to carbofuran treated rats resulted in protective effect on the activities of these enzymes. Marked impairment in the motor function was seen following carbofuran exposure, which is evident by significant decrease in the retention time of the rats on rotating rods. Cognitive deficits were also seen after carbofuran exposure as indicated by the significant decrease in active avoidance response. NAC treatment significantly improved the carbofuran-induced neurobehavioral deficits. The results clearly demonstrate that carbofuran exerts its neurotoxic effects by accentuating oxidative stress and suggest neuroprotective role of NAC in carbofuran neurotoxicity.

Monitoring of organochlorine pesticide residues in summer and winter vegetables from Agra, India - a case study

Analysis of summer and winter vegetable samples during 2002-2003 for pesticidal contamination was carried out on Gas Chromatograph-Electron Capture Detector with capillary columns. The contamination levels of winter vegetables (average concentration of 4.57, 6.80 and 5.47 ppb respectively for Lindane, Endosulphan and DDT) were found to be slightly higher than the summer vegetables (average concentration of 4.47, 3.14 and 2.82 ppb respectively for Lindane, Endosulphan and DDT). The concentration of these organochlorine pesticides in summer and winter vegetables were well below the established tolerances but continuous consumption of such vegetables even with moderate contamination level can accumulate in the receptor's body and may lead to chronic effects that could be fatal.

Risk assessment through dietary intake of total diet contaminated with pesticide residues in Punjab, India, 1999-2002

Forty-six samples each of vegetarian and nonvegetarian total diet consumed from March 1999 to December 2002 by male subjects in the age group of 19-24 years were analyzed to assess their risk through dietary intake with respect to pesticide residues. The results revealed low dietary intake of levels of Sigma-dichlorodiphenyltrichloroethane (DDT) and which were almost comparable to levels reported in developed countries. The results are indicative of contamination of total diet with pesticide residues despite a ban on the use of DDT and restricted use of lindane in agriculture only. Predominance of lindane residues indicates that liquid milk was a main contributory source as it comprises almost 21% to the total diet consumed per day. Concerted efforts by regulatory authorities and emphasis on judicious use of agrochemicals in pest control are required to decrease the burden of these chemicals in food stuffs to levels safe for dietary intake.

Monitoring of butter and ghee (clarified butter fat) for pesticidal contamination from cotton belt of Haryana, India

Butter (45) and ghee (55) samples were collected from rural and urban areas of cotton growing belt of Haryana and analysed for detecting the residues of organochlorine, synthetic pyrethroid and organophosphate insecticides. The estimation was carried out by using multi residue analytical technique employing GC-ECD and GC-NPD systems equipped with capillary columns. Butter samples were comparatively more contaminated (97%) than ghee (94%), showing more contamination with organochlorine insecticides from urban samples. About 11% samples of butter showed endosulfan residues above MRL value and 2% samples had residues of synthetic pyrethroids and organophosphates each above their respective MRL values. In ghee, residues of HCH & DDT both and of endosulfan exceeded the MRL values in 5 and 20% samples, respectively. Among organophosphates, only chlorpyriphos was detected with 9% samples showing its residue above MRL value. Irrespective of contamination levels, residues above the MRL values were more in ghee. More extensive study covering other agricultural regions/zones of Haryana has been suggested to know the overall scenario of contamination of milk products.

Mammalian Voltage-Gated Calcium Channels Are Potently Blocked by the Pyrethroid Insecticide Allethrin

Pyrethroids are commonly used insecticides for both household and agricultural applications. It is generally reported that voltage-gated sodium channels are the primary target for toxicity of these chemicals to humans. The phylogenetic and structural relatedness between sodium channels and voltage-gated calcium (Ca) channels prompted us to examine the effects of the type 1 pyrethroid allethrin on the three major classes of mammalian calcium channels exogenously expressed in human embryonic kidney 293 cells. We report that all classes of mammalian calcium channels are targets for allethrin at concentrations very similar to those reported for interaction with sodium channels. Allethrin caused blockade with IC(50) values of 7.0 microM for T-type alpha(1G) (Ca(v)3.1), 6.8 microM for L-type alpha(1C) (Ca(v)1.2), and 6.7 microM for P/Q-type alpha(1A) (Ca(v)2.1) channels. Mechanistically, the blockade of calcium channels was found to be significantly different than the prolonged opening of mammalian sodium channels caused by pyrethroids. In all calcium channel subtypes tested, allethrin caused a significant acceleration of the inactivation kinetics and a hyperpolarizing shift in the voltage dependence of inactivation. The high-voltage-activated P/Q- and L-type channels showed a frequency of stimulation-dependent increase in block by allethrin, whereas the low-voltage-activated alpha(1G) subtype did not. Allethrin did not significantly modify the deactivation kinetics or current-voltage relationships of any of the calcium channel types. Our study indicates that calcium channels are another primary target for allethrin and suggests that blockade of different types of calcium channels may underlie some of the chronic effects of low-level pyrethroid poisoning.

Competitive degradation and detoxification of carbamate insecticides by membrane anodic Fenton treatment

The competitive degradation of six carbamate insecticides by membrane anodic Fenton treatment (AFT), a new Fenton treatment technology, was carried out in this study. The carbamates studied were dioxacarb, carbaryl, fenobucarb, promecarb, bendiocarb, and carbofuran. The results indicate that AFT can effectively degrade these insecticides in both single component and multicomponent systems. The carbamates compete for hydroxyl radicals, and their kinetics obey the previously developed AFT kinetic model quite well. Hydroxyl radical reaction rate constants were obtained, and they decrease in the following order: dioxacarb approximately carbaryl > fenobucarb > promecarb > bendiocarb > carbofuran. The AFT is shown to have higher treatment efficiency at higher temperature. Degradation products of the carbamates were determined by gas chromatography/mass spectrometry, and it appears that degradation can be initiated by hydroxyl radical attack at different sites in the molecule, depending on the individual structure of the compound. Substituted phenols are the commonly seen degradation products. The AFT treatment can efficiently remove the chemical oxygen demand of the carbamate mixture, significantly increasing the biodegradability. Earthworm studies show that the AFT is also an effective detoxification process.