• Korean journal of applied entomology
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• v.36 no.1
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• pp.105-110
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• 1997

Mixture study of bifenthrin and prothiofos was conducted to control insecticide resistant diamondback moth (DBM), Plutella xylostella, which had shown 581, 18, 19, 11 fold resistance to fenvalerate, cypermethrin, furathiocarb, and prothiofos in Chinju strain, respectively and 38 and 9 fold resistance to fenvalerate and furathiocarb in Seosang strain, respectively. Optimal mixture ratios of bifenthrin and prothiofos was selected against Seosang strain of DBM by leaf dipping method in laboratory and by field test. Maximum co-toxicity coefficient by dipping method was shown at a ratio of 1:50 mixture of bifenthrin 1EC and prothiofos 50EC in active ingredient(a.i.) by 243.2 and then suddenly decreased. The mixed formulation from the dipping test was examined at the cabbage field of Seosang, Hamyang. Although insecticides were reduced to half, control efficacy was similar to farmer's conventional method. In addition, the mixture combination was also more effective against Chinju DBM population which had very high level of resistance to several representative insecticides. Mixture methods of insecticides will be effective countermeasures to the resistance problem of pests.

• The Korean Journal of Pesticide Science
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• v.15 no.1
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• pp.48-54
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• 2011

Risk assessments of pesticides detected in six major rivers during peak season were estimated for algae, Daphnia, and fish using hazard quotient (HQ) indexes. The eight pesticides (isoprothiolane, hexaconazole, diazinon, chlorpyrifos, prothiofos, alachlor, butachlor, molinate) were detected within the range of 0.027~12.871 ${\mu}g/L$. Detection frequency of isoprothiolate was estimated to be high at 67.5%, and those of the others varied from 15.0 to 37.5%, Hazard Quotients (HQ) indexes varied by freshwater organisms (algae, Daphnia, and fish). Overall, the ecological risk probability due to exposure of pesticides detected in major rivers did not reveal based on HQ indexes below 1.0. Particularly, butachlor and molinate for algae, chlorpyrifos, diazinon, prothiofos for Daphnia, and chlorpyrifos for fish acted as dominant contributors in increasing the ecological risk in six major rivers. This implied that integrated ecological risk assessment is required using various biological species, reflecting toxicity sensitivity. This study may provide the essential data in establishing the priority for pesticides management in major rivers, Korea.

• Journal of Food Hygiene and Safety
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• v.17 no.2
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• pp.87-93
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• 2002

The removal of three pesticides which were residued in chinese cabbage was investigated during making process of Kimchi. When chinese cabbage was washed by water, the removal rates of three pesticides were 62.0%, 54.8% and 61.1% for pirimiphos-methyl, chlorpyrifos and prothiofos, respectively. Pesticides remaining in chinese cabbage after washing by water were also removed from 22.4% to 23.8% by salting. During the fermentation of kimchi for 24 days at 4。C, the pH was lowered 4.5 from 5.8 and the residual amount of pesticides was decreased by 51.4% to 69.4% for three Pesticides remaining after washing and salting On the other hand, when Kimchi was fermented under various temperature for 11 days, the residual amount of chlorpyrifos was decreased up to 29.2%, 45.0% and 77.3% of initial concentration at 4, 10 and 20 。C, respectively. The residual amount of chlorpyrifos in Kimchi was decreased up to 16.3% by heating at 100 。C for 6.5 minutes.

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2004.05a
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• pp.166-166
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• 2004

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2003.10a
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• pp.165-165
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• 2003

• Journal of the Korean Society for Marine Environment & Energy
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• v.5 no.1
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• pp.38-50
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• 2002

To study the distribution of organophosphorus pesticides which are extensively used for agriculture in Korea. Surface sea water samples were taken from 2 coastal areas during July and :;eptember of 1999 and sediment samples were collected from Kyeonggi bay in July of 1999. These samples were analyzed using a Gas Chromatography/Nitrogen Phosphorus Detector(GC/NPD). In coastal waters of the study areas IBP was commonly found the most compound. Traces of Diazinon, DDVP, Ethoprouhos and Chlorpyrifos were also encountered. Concentration of the other major organophosphorus pesticides(Disulfoton, Parathion Methyl, Fenchlorfos, Prothiofos, EDDP) were generally be below the detection limit of the employed analytical method. Tn sediment of the study areas Chlorpyrifos w3s found the most compound. Temporal and geographical distribution of individual organophosphorus pesticides is likely to be affected by types of agricultural practices in the watershed.

• The Korean Journal of Pesticide Science
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• v.8 no.3
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• pp.189-197
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• 2004

Alpine and sloped-land in Gangwondo, Korea is the most important land type for cultivation of Chinese cabbage. However, farmers in these regions have major problems with insect pests, weeds and disease. Over use or inappropriate use of agrochemicals occurs frequently. No intensive study of pesticide contamination in this area has been done. The work presented in this paper addresses this deficiency. We measured pesticide residues within soil and water samples using multiresidue analysis. Samples were collected bimonthly from April to October, 2002 at three sites with to sampling spots. At the three sites, Pyeongchang, Jeongseon and Taebaeck, pesticides most frequently detected (>30% of samples) in soil samples were endosulfan, fluazinam, diniconazole, alachlor, prothiofos and dimethomorph. The amount of pesticide residues in the soils was ranged from 0.004 to $0.412\;mg\;kg^{-1}$ in these samples. Non-registered pesticides were also detected in these samples, indicating illegal use of pesticides. No pesticide were detected in the water samples collected from those sites. The results showed that pesticide residues might be dependant on physiochemical properties of pesticides, application history and soil properties. This study provides basic data for appropriate pesticide use on alpine and sloped-land in Korea.

• Korean Journal of Food Science and Technology
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• v.44 no.5
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• pp.628-633
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• 2012

This study investigated the washing efficiency of electrolyzed water for the removal of microorganisms and pesticide residues from Chinese cabbage. Initial total bacteria and coliform counts were 6.64 and 3.56 log cfu/g respectively. After washing, total bacteria count of tap water (TW) were 5.97 log cfu/g and low alkaline electrolyzed water (LAlEW) and strong acidic electrolyzed water (SAcEW) were 1.63-4.67 log cfu/g. Especially SAcEW-100 was found to the most effective method of washing the cabbages. After washing, the coliform count was dramatically reduced. The removal rate of pesticide residues by NaClO treatment (36.93-50.13%) was greater than that of TW treatment (32.28-38.46%). The removal rate of LAlEW-100 and SAcEW-100 was 63.79 and 78.30% respectively, and was higher than those of TW and NaClO treatments. The vitamin C content of the Chinese cabbages after all treatments did not differ significantly. Consequentially, the electrolyzed water was found to be effective to remove bacteria and pesticide residues from Chinese cabbage without affecting quality.

• Korean journal of applied entomology
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• v.32 no.3
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• pp.323-329
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• 1993

These studies were conducted to evaluate the five comparative test methods for detecting chemical resistance and to investigate resistant level of field populations of diamondback moth (Plutella xylostella L.). Leaf disc method was practically rocomrnendable because of its rapidity and low CV(l1.4%). Topical application method was a precise replicabiliLy(CV=8.00/0) but it was time consuming and difficult in mampulation. The other 3 methods showed higher CV ranging from 14.9% to 21.4%. Based on $LC_{50}$ values by topical application method, field populations of diamondback moth collected from 4 different regions, Kwangju, Kimhae, Jeju, and Inje to prothiofos showed from 3.3 to 61.1 times higher resistance than the susceptible strain, whereas to cypermethrin, Lhey were from 7.5 to 141.7 times higher than the susceptible. To cartap hydrochloride, they showed from 10.5- to 33.3-fold resistant levels as high as the susceptible. Finally, based on $LC_{50}$ values to Bacillus thuringiensis by leaf disc technique, the resistant levels of the field populations were from 1.9 Lo 8.1 times as compared to the susceptible.

• The Korean Journal of Pesticide Science
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• v.16 no.2
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• pp.85-97
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• 2012

The monitoring of pesticide residues was performed on 33 fruit commodities collected in Gyeonggi-do, Korea from 2006 to 2010. Pesticide residues were detected in 431 samples (16.8%) of total 2,558 samples and violated in 12 samples (0.5%). Annual detection rate showed 6.9%~19.4% with the rate of violation of 0.3%~0.9%. Twenty three samples (69.7%) of 33 commodities were detected and 4 samples (12.1%) were violated. Eight pesticides (EPN, dicofol, carbaryl, procymidone, methidathion, prothiofos, fenitrothion and phenthoate) were violated and 62 pesticides were detected. Chloropyrifos was detected most frequently. The rate of detection and violation of citrus fruits in fruits showed the highest level. Organophosphorus pesticides (35%) and insecticide (57%) were detected most frequently. The hazard index (%ADI) of chronic dietary risk assessment by deterministic approach showed that the lower limit value and upper limit value for the whole population were 0.0000~0.7526 and 0.0000~1.3237 respectively. For the only consumer group, the lower limit value and upper limit value were 0.0006~9.7801 and 0.0058~15.9258 respectively. Therefore the hazard index for the whole population and the only consumer group were evaluated as a safe level.