• Journal of agricultural medicine and community health
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• v.36 no.4
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• pp.218-226
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• 2011

Objectives: Paraquat (PQ) is a widely used ionic pesticide that is fatal when ingested accidentally or for suicidal purposes. It is thought that chronic exposure of PQ is related with the development of Parkinson's disease, but epidemiological studies have not yet confirmed that theory. This study attempted to estimate the possibility of environmental PQ exposure through soil and water. Materials and Methods: We analyzed the amount of decomposed PQ solution in wet soil after exposure to ultraviolet light. An artificial rainfall condition was simulated over soil sprayed with PQ to measure the amount of eluted PQ. In addition, PQ was diluted in water from three differently rated rivers and the changes in PQ concentration were measured after ultraviolet exposure over one month. High performance liquid chromatography/ultra violet detection was used to analyze the concentrations of PQ. Results: In the method we used, the recovery rate of PQ showed a precision rate less than 5%, an accuracy greater than 88%, and the calibration equation was y=5538.8x-440.01($R^2$=0.9985). There were no significant differences in the concentrations of PQ obtained from the three specimens over a 1-week period. From the PQ-sprayed soil, the artificial rainfall conditions showed no PQ elution over a 1-month period, and there was no significant differences in PQ concentrations according to ultraviolet exposure among the three samples. Conclusions: PQ remains well adsorbed naturally in soil. However, it may still exist in an integrated state for a long time in the hydrosphere, so the possibility of PQ exposure through drinking water cannot be disqualified.

• Journal of Nutrition and Health
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• v.44 no.5
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• pp.443-452
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• 2011

The characteristics of pesticide residues were examined in 18,069 samples from 91 vegetable commodities collected in Seoul from 2007 to 2009, and the vegetable dietary intakes of Seoulites were estimated using the Korea National Health and Nutrition examination survey data from 2008. The hazard index was calculated using vegetable pesticide residues and dietary vegetable intake by Seoulites. Detection rates for pesticide residues in vegetables were 11.2 % in 2007, 8.6 % in 2008, and 12.0 % in 2009. Excess rate of Maximum Residue Limits tended to decline from 4.6 % in 2007, to 2.8 % in 2008, and 2.1 % in 2009.Daily vegetable intake for Seoulites was 288.12 ${\pm}$ 214.8 g, and vegetable intake by males was more than that of females (p < 0.001). The hazard index was the highest at $2.76{\times}10^{-2}$ in 2007, and the lowest at $1.69{\times}10^{-2}$ in 2009. The risks caused by multiple pesticides in vegetables were very low and vegetable intake was safe considering the hazard index values.

• The Korean Journal of Pesticide Science
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• v.19 no.3
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• pp.230-240
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• 2015

An IOM sampler equipped with glass fiber filter has been recently utilized instead of solid adsorbent, which was used to measure the inhalation exposure of agricultural operator to pesticides. The aim of this study is to validate the efficacy of an IOM sampler by measuring the trapping efficiency and breakthrough using kresoxim-methyl water-dispersible granule and fenthion emulsifiable concentrate. On LC-MS/ MS, minimum detection level was 12.5 pg and method limit of detection was 5.0 ng/mL. Good linearity ($R^2$ > 0.999) for matrix matched standards was obtained. Recoveries of pesticides from glass fiber filter were 102-109% (kresoxim-methyl) and 97-104% (fenthion) while those from XAD-2 resin were 94-98% (kresoxim methyl) and 93-100% (fenthion). Trapping efficiency test was performed with personal air pumps and IOM sampler (glass fiber filter) connected with solid adsorbent (XAD-2 resin) with two types of formulation (solid and liquid) which were diluted by standard rate and sprayed to IOM sampler. Those pesticides were trapped only in glass fiber filter without any breakthrough to solid adsorbent. After spiking of pesticides to glass fiber filter, breakthrough test was carried out with IOM sampler (glass fiber filter) which was connected with solid adsorbent. As a results, 87-101% of kresoxim-methyl and 96-105% of fenthion remained in spiked glass fiber filter, however, no pesticides were detected in second glass fiber filter and solid adsorbent. In conclusion, IOM sampler which equipped with glass fiber filter can be applied widely for pesticide inhalation exposure study since it has good trapping efficiency and adsorption capacity, regardless of the solid or liquid formulation.

• Journal of Preventive Medicine and Public Health
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• v.32 no.3
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• pp.347-354
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• 1999

Objective: This paper examines the possible toxicity to immune system in farmers chronically exposed to pesticides. Methods : We compared 43 male farmers exposed to pesticides with 29 male residents who had neither past nor current pesticides exposure. The selected variables for studying immunotoxicity were WBC, CD3, CD4, CD8, CD19, CD56, IgG, IgA, IgM, and IL-2. As part of the baseline questionnaires for the immunotoxicity, subjects were asked about kinds of farming, posticides exposure and medical history. Results : None of the variables for studying immunotoxicity showed statistically significant difference between the two groups. Although the results were not statistically significant, CD4 and the CD4/CD8 ratio decreased and CD8 increased. These effects showed a dose response change with exposure level. In the exposed group, the values of CD3, CD4, CD4/CD8 and CD19 decreased and those of the CD8 and CD56 increased compared to the non-exposed group. Also there was higher prevalence of self-reported disease in the exposed group compared to the non-exposed group. Conclusions: Although statistically significant differences in indices of immunotoxicity in farmers exposed to pesticides were not shown, the results suggest that pesticides may decrease immune function. More advanced test methods for immunotoxicity need to be developed and tested in larger population to detect immunotoxic effects of pesticides.

• Food Science of Animal Resources
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• v.41 no.6
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• pp.1022-1035
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• 2021

This study estimated the effect of exposure to propiconazole through implementation and residues in finishing pigs. We analyzed the expression of fibrosis-related genes and performed histological analysis of the blood, liver, kidney, muscle, ileum, and fat tissues. The animals were exposed for 28 d to different concentrations of propiconazole (0.09, 0.44, 0.88, 4.41, and 8.82 mg/kg bw/d). Quantitative, gene expression, and histological analyses in tissues were performed using liquid chromatography mass spectrometry, real-time PCR, and Masson's trichrome staining, respectively. Final body weight did not differ among groups. However, genes involved in fibrosis were significantly differentially regulated in response to propiconazole concentrations. Glucose, alanine aminotransferase, and total bilirubin levels were significantly increased compared with those in the control group, while alkaline phosphatase level was decreased (p<0.05) after exposure to propiconazole. The residue limits of propiconazole were increased in the finishing phase at 4.41 and 8.82 mg/kg bw/d. The liver, kidney, and ileum showed blue staining after propiconazole treatment, confirmed by Masson's trichrome staining. In conclusion, these findings suggest that propiconazole exposure disturbs the expression of fibrosis-related genes. This study on dietary propiconazole in pigs can provide a basis for determining maximum residue limits and a better understanding of metabolism in pigs and meat products.

• Korean Journal of Environmental Agriculture
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• v.41 no.3
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• pp.153-157
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• 2022

BACKGROUND: The residue dissipation pattern of pesticides for agricultural products during the pre-harvest period after the final application is important to prevent the maximum residue limit (MRL) violations in domestic and export markets. The MRL violations of carbendazim are observed more often in chamnamul by pesticide residue management surveys by the Ministry of Food and Drug Safety. The residue level at the pre-harvest interval (PHI) and the residue dissipation constant from the critical good agricultural practice (cGAP) trials could be estimated to meet the MRL and pose a health risk to consumers. METHODS AND RESULTS: Chamnamuls were harvested at 0, 1, 3, 5, 7, 10, and 14 days after application of carbendazim in accordance with critical GAP. The residue analysis in chamnanul was performed by HPLC-DAD with the C₁₈ column. The limit of quantitation of carbendazim was 0.04 mg/kg, and the recoveries were 74.4 - 95.8% at the two spiked levels (LOQ and 10LOQ) of carbendazim. The dissipation rates in chamnamul were calculated from the residues at the sampling days by statistical method at a 95% confidence level. The biological half-lives of residual carbendazim in the field trials 1 and 2 were 4.9 and 4.4 days, respectively. CONCLUSION(S): In this dissipation study, the residue concentrations at the recommended PHI were higher than the established MRL in Korea. Therefore, the MRL is proposed based on the residue data sets from the trials conducted at the same cGAP and the dietary exposure assessment.

• The Research Journal of the Costume Culture
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• v.7 no.3
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• pp.142-153
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• 1999

The objective of this study was to analysis the pesticide chemical-using of farm workers and working clothes for diminishing the possible damage by their improper chemicals usages. For the data Questionairs were collected 340 from the farm families of the 3 different districts in Yeoju, Kyonggido, and also inquired of the persons in charge of the chemicals and of the laundry in each family. Among the replies, 233 was classified as useful, and analyzed the frequency, the percentage and correlation. The results were as follows : 1. 64.3% of the farmers were using the chemicals for 5∼20 years, of whom 33.6% experienced stopping of chemicals-using for health. 2. The applicators experienced poisoning symptoms such as habitual fatigue, hadache, dizziness, chest discomfort, eye irritation, skin irritation, blurred vision, vomiting, nausea etc. after chemical work. 3. 74.7% answered they did not obtained educational information for the care of chemicals contaminated clothes. 69.1% said they need to obtain educational information about safety awareness of agricultural chemicals.

• Korean journal of applied entomology
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• v.31 no.3
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• pp.289-303
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• 1992

Investigation of the environmental impact of widespread pesticide use has revealed a virtue/vice relationship. Although many pesticides perform their function and disappear without harm to the environment, others persist beyond their useful purpose and cause direct of indirect hazard to man, domestic animals and wildlife. Concurrently, many pests have rapidly adjusted to chemical control practices through changes in behavior that avoid exposure to pesticides of throuth genetic selection for populations resistant to the toxicants. The prospect of losing control over insect herbivores and desease vectors and returning to the days of global hunger and disease is unthinkable. Fortunately, from basic studies of insect and plant biology many opportunities for the development of safe, selective and environmentally pacific strategies for insect pest management are being realized.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.500-510
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• 1996

A Direct injection -mixing total -flow -control sprayer was developed and evaluated . The system provided precise application rates and minimized operator exposure to chemicals as well as providing a possibility for recycling container so f unused chemicals that can causes environmental contamination. Chemicals were metered and injected proportionally to the diluent flow rate to provide constant concentrations. The main diluent flow was varied in response to changes in travel speed. Experimental variables of the sprayer were the control interval, the sensitivity of flow regulating valve, the tolerance of control object and the sensitivity of the injection pump system. The optimal performance of the flow control system was with an average response time of 8.5 sec at an absolute steady state of error of 0.067 L/min (0.8% of flow rate). The average response time of the injection rate was -0.53 sec and the coefficient of variation (CV) of concentration was 3.2%.

• Journal of Environmental Health Sciences
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• v.26 no.2
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• pp.49-58
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• 2000

The present study was performed to investigate photodegradation rate constants and degradation products of phosphamidon and profenofos by the USEPA method. The two pesticides were very stable in 16 days exposure of sunlight from September 3 to 22, 1999 and humic acid had no sensitizing effect on the photolysis of each pesticide in sunlight. In the UV irradiation test, phosphamidon was rapidly degraded as increasing UV intensity. In case of UV irradiation with TiO2 and with TiO2 powder amount, degradation of profenofos showed no significant difference with UV irradiation. Photodegradation rate of profenofos was slower than that of phosphamidon. In order to identify photolysis products, the extracts of degradation products were analyzed by GC/MS. The mass spectra of photolysis products of phosphamidon were at m/z 153 and 149, those of the profenofos were at m/z 208 and 240, respectively. It was suggested that the photolysis products of phosphamidon were 0, 0-dimethyl phosphate(DMP) and N, N-diethylchloroacetamide, those of profenofos were 4-bromo-2-chlorophenol and 0-ethyl-S-propyl phosphate.