• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.10a
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• pp.57-69
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• 2003

It is well known that many pesticides possess hormonal activity, and affect the developments of wildlife and mammals including human. Currently, pyrethroid insecticides are in worldwide use to control in and outdoor pests, providing potential far environmental exposure. Hormonal activities of these pyrethroid insecticides, however, have been little studied, and the developmental effects of them were no reported. Therefore, we firstly examined the potential estrogenic activities of some pyrethroid insecticides (permethrin, cypermethrin, tetramethrin, deltamethrin, sumithrin, fenvalerate and bioallethrin) by immature rat uterotrophic assay, luciferase reporter gene assay and Calbindin-D$\sub$9k/ (CaBP-9k) gene expression assay. Uterine wet weights were increased by permethrin and the permethrin-induced weights were inhibited by ICI 182780 in the uterolrophic assay. On the other hand tetramethrin significantly reduced uterine and vaginal wet weights, and also inhibited the E2-induced weight increases at all doses tested. Cypermethrin and sumithrin had a tendency to increase uterine weights, although not statistically significant. Permethrin and cypermethrin dose-dependently increased the luciferase activity in reporter gene assay. Northern blot analysis showed that permethrin induced CaBP-9k mRNA expression whereas tetramethrin inhibted. Subsequent studies were conducted to investigate the possible developmental effects of four pyrethroid insecricides (permethrin, cypermethrin, sumithrin and teramethrin). Either diethlbestrol (DES) or 17${\beta}$ -estradiol (E2) was used as a reference control in this study. Pyrethroid insecticides were administered to Sprague Dawley rats via subcutaneous injection at 6 to 18 days of gestation or 1 to 5 days after birth. In utero treatment of permethrin (10mg/kg/day) in female rat resulted in significant increases in uterine and ovarian weights while significant decreases in serum E2 concentration, uterine and ovarian ER${\alpha}$ mRNA levels. Sumithrin and permethrin led to acceleration in vaginal opening of female rat, while delay in preputial separation of male after neonatal treatment. Anogenital distances of PND 18 were significantly reduced in sumthrin-treated, and permerhrin-treated male rats after neonatal treatment. All the pyrethroid insecticides tested caused significant increases in uterine weights on PND 18, while significant reductions in the first diestrus phase when neonataly treated. In addition, exposure to pyrethroids in neonatal period led to significant reduction in relative brain weight in female rat on PND 18, but its weight was recovered in diestrus phase. In summary, Our experimental data demonstrate the possibilities of developmental effects of pyrethroid insecticides via estrogenic or antiestrogenic activity.

• Toxicological Research
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• v.31 no.4
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• pp.331-337
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• 2015

Synthetic pyrethroids (SPs) are the most common pesticides which are recently used for indoor pest control. The widespread use of SPs has resulted in the increased exposure to wild animals and humans. Recently, some SPs are suspected as endocrine disrupting chemicals (EDCs) and have been assessed for their potential estrogenicity by adopting various analyzing assays. In this study, we examined the estrogenic effects of lambda-cyhalothrin (LC) and cypermethrin (CP), the most commonly used pesticides in Korea, using BG-1 ovarian cancer cells expressing estrogen receptors (ERs). To evaluate the estrogenic activities of two SPs, LC and CP, we employed MTT assay and reverse-transcription polymerase chain reaction (RT-PCR) in LC or CP treated BG-1 ovarian cancer cells. In MTT assay, LC ($10^{-6}M$) and CP ($10^{-5}M$) significantly induced the growth of BG-1 cancer cells. LC or CP-induced cell growth was antagonized by addition of ICI 182,720 ($10^{-8}M$), an ER antagonist, suggesting that this effect appears to be mediated by an ER-dependent manner. Moreover, RT-PCR results showed that transcriptional level of cyclin D1, a cell cycle-regulating gene, was significantly up-regulated by LC and CP, while these effects were reversed by co-treatment of ICI 182,780. However, p21, a cyclin D-ckd-4 inhibitor gene, was not altered by LC or CP. Moreover, $ER{\alpha}$ expression was not significantly changed by LC and CP, while down-regulated by E2. Finally, in xenografted mouse model transplanted with human BG-1 ovarian cancer cells, E2 significantly increased the tumor volume compare to a negative control, but LC did not. Taken together, these results suggest that LC and CP may possess estrogenic potentials by stimulating the growth of BG-1 ovarian cancer cells via partially ER signaling pathway associated with cell cycle as did E2, but this estrogenic effect was not found in in vivo mouse model.

• Korean journal of applied entomology
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• v.48 no.3
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• pp.301-310
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• 2009

For the comparing of mortality of the resistance and susceptible population of Myzus persicae, etofenprox was treated in the recommended concentration of 200ppm. Mortalities of resistance population were 16.7 and 36.7%, and susceptible population were 86.7 and 86.7% after 24 and 48 hours treatment, respectively. For the detect of cross resistance to other pyrethroids, 6 pyrethroids were examined. Mortalities of susceptible and resistance populations were 90 and 31% to deltamethrin, 92 and 23% to lambda cyhalothrin, 81 and 14% to cypermethrin, 70 and 20% to $\alpha$-cypermethrin, 29 and 28% to fenpropathrin, 84 and 29% to fenvalerate, respectively. It was showed that resistance populations were generally resistive to other pyrethroids. On the other hands, for recognized ecological characteristic of M. persicae susceptible and resistance populations life table was tested on the pepper leaves in the petri dish and on the plant in the pot. This results were showed that intrinsic rate of increase ($r_m$), net reproduction number ($R_0$) and generation time in day ($T_c$) were significantly different between two population in both tested. However, life span and reproduction period were slightly different between them. Otherwise, feeding behaviors were tested using EPG technique with non- and treated etofenprox. First potential drop time of susceptible and resistance population was 73.5 and 257.9 sec with non-treated and 93.3 and 1076.2 sec after treated, respectively. Electrical probing signals were 8.2 and 48.8 times with susceptible and resistance individuals after treated etofenprox, respectively. It was supposed that the resistance is more probings than susceptible population. After treated, total feeding time have more 6,728.9 sec on resistance than 965.5 sec on susceptible population. So, total non penetration time of susceptible population was 3,000 sec longer than resistance population.

• Journal of Environmental Health Sciences
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• v.27 no.1
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• pp.88-92
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• 2001

The simultaneous analytical method for 37 residual pesticides was developed by a gas chromatography with $^{63}$ Ni electron capture detector. Pesticides added in soybean sample were extracted with 70% acetone in water and methylene chloride in oder, and then cleaned up via open-column apparatus packed with florisil and alumina N. The Ultra-2 fused capillary column was used to separate the products. The resolution between the last isomeric peak of cypermethrin (56.398 min) and the first isomeric peak of flucythrinate (56.421 min) was not satisfactory and the last isomeric peak of fenvalerate(58.783 min) and the first isomeric peak of fluvalinate(58.835 min) was overlapped. Except for $\alpha$-BHC, dichlofluanid, captan, and captafol, most recoveries were showed over 70%.

• Korean Journal of Environmental Agriculture
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• v.21 no.2
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• pp.90-95
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• 2002

A study was carried out to optimize the cleanup step using a solid-phase extraction (SPE) cartridge, $SupelClean^{TM}$ Florisil, for multiresidue analysis of 16 pesticides in cucumber matrix. Eluting efficiencies of two solvent systems including acetone/n-hexane and ethyl acetate/n-hexane mixtures were critically evaluated by recoveries of target anaytes from the SPE Florisil column. Based on the recovery as a measure of eluting efficiency, an acetone/n-hexane (20/80,v/v) mixture provided more than 80% recovery for 15 pesticides except bifenthrin. In case of ethyl acetate/n-hexane, 14 pesticides showed recoveries higher than 75% while those far alachlor and bifenthrin were less than 30%.

• Food Science and Biotechnology
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• v.15 no.1
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• pp.57-62
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• 2006

Six organophosphorus, one organochlorine, and three synthetic pyrethroid pesticides were analyzed for their residues during washing and hot-air drying of red peppers conducted in the production of powder. The residue ratio in organophosphorus pesticides was 33% in chlorpyrifos, 31 % in diazinon, 50% in methidathion, 80% in EPN, 28% in fenitrothion, and 60% in profenofos. The ratio in pyrethroids was 109% in cypermethrin, 102% in deltamethrin, and 106% in fenvalerate. That in organochlorine was 56% in ${\alpha}$-endosulfan and 90% in ${\beta}$-endosulfan. The results were greatly different between organophosphorus and pyrethroid pesticides. UV irradiation along with hot-air drying brought about a remarkable reduction of the residues, up to 70% as compared with hot-air drying only. The removal effect was most remarkable in pyrethroids, which are hardly removed by hot-air drying. The color of the pepper was not changed during UV irradiation. The use of oxidizing agents such as hydrogen peroxide or chlorine dioxide during washing did not show a remarkable removal of residues. The residue ratio was not affected whether the pesticide is contaminated artificially or naturally.

• Korean journal of applied entomology
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• v.46 no.3
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• pp.415-423
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• 2007

For the development of integrated pest management system by harmonizing biological and chemical control, some experiments were carried out to select low toxic pesticides and to evaluate residual toxicity to natural enemies. Leaf dipping method and body dipping method were set up for evaluating toxicity to minute pirate bug, Orius strigicollis adult. We had tested 52 kinds of pesticides (33 insecticides, 19 fungicides) commonly used to control greenhouse insects, mites, and disease pests to natural enemies at the recommended concentration. Fourteen insecticides by body dipping method, 12 insecticides by leaf dipping method and 19 fungicides were selected as low toxic pesticides to O. strigicollis adult. After insecticide spraying at recommending dose on the sweet pepper plant, we examined residual effect of insecticides by introducing natural enemies on different days. Safety interval for introduction of O. strigicollis adult was established according to residual toxicity of pesticides. Safety insecticides at one day after treatment were pyraclofos, methomyl, thiodicarb, esfenvalerate bifenthrin, alpha-cypermethrin, etofenprox, fenvalerate, imidacloprid, acetamiprid, abamectin, emamectin benzoate, spinosad, indoxacarb. However, residual toxicity of nee-nicotinoids last up to 21 days to O. strigicollis adults.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.2
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• pp.197-202
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• 2005

The effects of feeding Brassica vegetable market wastes on intake, body weight changes and pesticide/insecticide residues in products of goats were evaluated in two experiments. In the first experiment (Exp. 1) 16 goats (Bach Thao, 9 to 10 kg, 3 months old, 9 males and 7 females) were fed four diets with leaves either from cabbage (Brassica oleracea var. capitata), cauliflower (Brassica oleracea var. botrytis) or Chinese cabbage (Brassica campestris subsp. pekinensis) with 30% of Para grass. The control group was fed 100% Para grass. All diets contained soybean waste as a supplement and the experiment lasted for 136 days. In the second experiment (Exp. 2) 24 goats (Bach Thao, 12 to 14 kg, all males) were assigned to three treatments in a completely randomised block design based on initial body weight. The goats were fed cabbage waste supplemented with 200 g or 100 g DM (dry matter) of concentrate. Para grass with 100 g DM concentrate supplementation was used as a control group. The experiment lasted for 90 days and at the end of the study, 12 goats were slaughtered for pesticide/insecticide analysis. Due to low DM content (5.3 and 3.7%, respectively) feed intakes of cabbage and Chinese cabbage groups were lower than those of other groups in the experiment. The highest feed intake and body weight gain was obtained when the goats were fed cauliflower (529 g DM/day and 87.5 g/day, respectively). In Exp. 2 total intake of cabbage and concentrate was similar (484 g and 453 g DM/day) whether the goats were fed 100 or 200 g concentrate/day but lower than that of Para grass and concentrate probably due to the low DM content of the cabbage (5.9%). Crude protein intake (79 g to 86 g/day) and body weight gain (70 g to 88 g/day) was not significantly different between treatments. Adding concentrate consequently resulted in higher DM intake than in Exp. 1 but did not result in any higher growth rate. Three of the pesticide/insecticide residues tested were found in cabbage, Alpha-Cypermethrin, Bassa-Fenobucarb and Dimethoate with levels of 0.175, 0.074 and 0.028 mg/kg fresh cabbage respectively. Weight of livers from goats fed cabbage was about 90 g higher than from goats fed Para grass but no pesticide/herbicide residues were found in meat or liver.

• Journal of Dairy Science and Biotechnology
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• v.33 no.1
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• pp.27-34
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• 2015

The aim of this study was to optimize a simple, fast, and economic analytical method for the simultaneous determination of various pesticides (aldrin, p,p'-DDT, o,p'-DDT, p,p'-DDE, ${\alpha}$-endosulfan, ${\beta}$-endosulfan, dieldrin, heptachlor, permethrin, chlordane, deltamethrin, diazinon, bifenthrin, methoprene, propargite, fenpropathrin, cypermethrin, fenvalerate, and fenpropathrin) in milk by using dispersive solid phase extraction (SPE). In this study, two different extraction methods (low temperature cleanup and liquid-liquid partitioning), which were followed by a cleanup process based on dispersive-SPE, were evaluated and compared for the 19 pesticides. The results for all the pesticides were determined by gas chromatography mass spectrometry (GC/MS) with selected-ion monitoring mode, and the matrix effect of the method was evaluated. Comparison of these approaches yielded higher and more consistent recoveries of most pesticides at fortification levels of $1{\mu}g/mL$ using low-temperature fat precipitation, followed by cleanup process based on dispersive-SPE with PSA and C18 as sorbents, than other preparation process. The relative standard deviation was <20 % and the combination of this method were very effective for the cleanup.

• 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.