• Agrochemical news magazine
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• v.23 no.4 s.177
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• pp.6-9
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• 2002

• Life and Agrochemicals
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• v.30 no.1 s.244
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• pp.34-35
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• 2009

• The Bimonthly Magazine for Agrochemicals and Plant Protection
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• v.2 no.12
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• pp.28-34
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• 1981

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.231-231
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• 1996

Paraquat(1.1'-dimethyl-4,4'-bipyridinium ion, PQ)는 전세계적으로 가장 많이 사용되고 있는 농약으로 자살 또는 실수로 마시는 경우 예외없이 폐독성으로 사망하게 된다. 하지만 아직까지 임상에 사용되어지고 있는 효과적인 독성 경감제는 전무한 실정이다. 현재까지 밝혀진 paraquat의 주된 독성기전은 NADPH Cytochrome P$_{450}$ reductase에 의해 산화,환원 반응을 거치는 동안 free radical을 생성하여 세포막에 지질과산화를 일으켜서 세포막의 기능상실과 cell death를 일으킨다고 보고되고 있다. 따라서 본 연구에서는 항산화작용이 뛰어난 아미노산인 taurine(TA)의 radical scarvenging 효과에 의한 PQ 독성경감효과를 in vivo에서 검색하였고, in vitro에서 TA의 PQ 독성경감 mechanism을 밝히고자 하였다. in vivo에서 PQ의 간독성(s-GOT,s-GPT), 신장독성(BUN, Creatinine), 폐 및 전신독성(ALP, MDA, G-6-phosphatase)의 정도를 혈액 및 조직균질액 중에서 검색함으로써 TA의 독성억제효과를 측정하였다.

• The Korean Journal of Pesticide Science
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• v.17 no.4
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• pp.343-349
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• 2013

Environment-friendly agro-materials tend to be preferred to chemical insecticides recently. For this reason, many studies are conducted to develop environment-friendly insecticides containing natural materials. The purpose of this study was to assess ecotoxicity for pepper extract and cassia oil (11.5+46%, A), pepper extract and cassia oil (23+34%, B), and pepper extract and lavender oil (40+10%, C). They are expected to prevent from pests especially diamondback moth, and can be used for agro-materials. Their formulation was emusifiable concentration (EC). Target species used to assess acute toxicity were aquatic invertebrate (Daphina magna), fish (Cyprinus carpio), honeybee (Apis mellifera L.) and earthworm (Eisenia fetida). The $EC_{50}$ value of A, B, and C to aquatic invertebrate were 0.46, 1.9, 0.25 mg $L^{-1}$ respectively and these values were moderately toxic according to standard of USEPA. In case of acute toxicity test to fish, the $LC_{50}$ of A, B, and C were 1.9, 2.9, 3.8 mg $L^{-1}$ respectively. A was category II in acute toxicity of fish and not acceptable to evaluation criteria of environment-friendly agro-materials. B and C were category III and acceptable. Acute contact and oral toxicity test to honeybee were conducted and the $LD_{50}$ of A, B, and C were > 100 ${\mu}g$ a.i. $bee^{-1}$ in both of tests. It indicated they were low toxic to honeybee. In case of acute toxicity test to earthworm, $LC_{50}$ of A, B, and C were 695, 988, and 564 mg $kg^{-1}$. In conclusion, pepper extract+cassia oil 57% EC and pepper extract+lavender oil 50% EC were expected to be used for environment-friendly insecticide materials with low risk against ecosystem and contribute to developing environment-friendly agro-materials.

• The Korean Journal of Pesticide Science
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• v.3 no.1
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• pp.57-65
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• 1999

The midge Chironomus riparius is a member of widespread dipteran insect which has been used for sediment toxicity test. The 2nd-3rd larvae Chironomus riparius were exposed to $^{14}C$-lambda-cyhalothrin in laboratory water only system(A) and sediment-water system(B) at $20{\pm}2^{\circ}C$. The concentration was nominally in the range of 0.16 to $20{\mu}g/{\ell}$ and 62.5 to 8000 ${\mu}g/kg$, respectively. System(A) was prepared by applying the chemical to 250 ml water and introducing Chironomus riparius larvae into the system(day 0). System(B) was prepared by applying the chemical to the 25 g of soil and 250 ml water and shaking and rolling them for two hours. After allowing the system to settle for two days, Chironomus riparius larvae were introduced into the system. After 72 hours, the two systems were terminated and dead larvae were observed. The measurement of residue in water was conducted at the start(day 0) and the end of the study(day 3). The residue of $^{14}C$-lambda-cyhalothrin in water was accounted for approximately 65% of nominal concentration in system(A) and $0.2{\sim}0.4%$ in system) on 3 days. $LC_{50}$ was less than $0.156{\mu}g/{\ell}$ in system(A) and 889 ${\mu}g/kg$ in system(B), based on the nominally applied concentration.

• Analytical Science and Technology
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• v.24 no.6
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• pp.544-555
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• 2011

The acute toxicity in the rainbow trout (Oncorhynchus mykiss) was analyzed and predicted using quantitative structure-activity relationships (QSAR). The aquatic toxicity, 96h $LC_{50}$ (median lethal concentration) of 275 organic pesticides, was obtained from EU-funded project DEMETRA. Prediction models were derived from 558 2D molecular descriptors, calculated in PreADMET. The linear (multiple linear regression) and nonlinear (support vector machine and artificial neural network) learning methods were optimized by taking into account the statistical parameters between the experimental and predicted p$LC_{50}$. After preprocessing, population based forward selection were used to select the best subsets of descriptors in the learning methods including 5-fold cross-validation procedure. The support vector machine model was used as the best model ($R^2_{CV}$=0.677, RMSECV=0.887, MSECV=0.674) and also correctly classified 87% for the training set according to EU regulation criteria. The MLR model could describe the structural characteristics of toxic chemicals and interaction with lipid membrane of fish. All the developed models were validated by 5 fold cross-validation and Y-scrambling test.

• Korean Journal of Environmental Agriculture
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• v.6 no.1
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• pp.50-60
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• 1987

Sensitivity, expressed in the $96h-LC_{50}$ determined with continuous flow system, was compared for eight developmental stages of Oryzias latipes with butachlor, diazinon and fenitrothion. Significance of the laboratory determined $96h-LC_{50}$ in real field situation was evaluated for butachlor using outdoor model agrosystem. In the laboratory tests, the most sensitive stage was post-larva stage IV(7 days after hatching) with $96h-LC_{50}$ of 0.14, 1.4, and 1.6ppm for butachlor, diazinon and fenitrothion, respectively, whereas the least sensitive stage was early embryo stage(1 day after fertilization), and then the susceptibility was somewhat stable after 21days after hatching. In the model agrosystem test, the highest concentration of 0.53ppm of butachlor in water was obtained at the 2nd day after application. The stages IV and VIII showed mortality of over 50% at 96 hours after application. It is concluded that the conventional use of butachlor in the field would cause significant adverse effect on O. latipes. It is suggested that sensitivity test at the early life stages with fish is an important part of the ecotoxicological assessment of chemicals.

• The Korean Journal of Pesticide Science
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• v.12 no.3
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• pp.215-221
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• 2008

To assess the impact of molinate on freshwater aquatic organisms, acute and chronic toxicity studies for waterfleas were conducted. In acute toxicity studies for Daphnia magna, and Moina macrocopa, the 48-h $EC_{50}$ values were 11.4 and 8.3 mg/L respectively. And in reproduction toxicity studies for the same species, the NOEC's were 2.5 and 2.0 mg/L respectively. These results suggest that waterfleas have simillar sensitivity to molinate. On the other hand, the NOEC for 3-generation toxicity of moina macrocopa 0.16 mg/L, was much lower than those of acute values. This studies concludes that molinate has minimal risk to waterfleas in river.

• Journal of the Korean Applied Science and Technology
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• v.41 no.2
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• pp.484-497
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• 2024

Neonicotinoid pesticides, widely used worldwide as potent insecticides, have been found to have detrimental effects on the environment and living organisms due to their persistent residues. This study aimed to investigate the neonicotinoid pesticides, imidacloprid, and clothianidin, focusing on their impact on honey bee toxicity and foliar residue levels. Alfalfa was selected as control crop while bell peppers, and cucumbers were chosen as representative application crops, respectively. The investigation involved comparing the toxicity and foliar residue levels resulting from soil and foliar treatments, with a focus on identifying potential shortcomings in conventional foliar residue toxicity testing methods. Imidacloprid and clothianidin were applied to crops or soil at recommended rates and through irrigation. The honey bee mortality rate (RT₂₅) over time was determined, and pesticide residues on leaves were quantified using High-Performance Liquid Chromatography (HPLC). The results revealed that foliar treatment with imidacloprid on alfalfa resulted in an RT₂₅ of less than 1 day, with residues ranging from 1.07 to 19.27 mg/kg. In contrast, application on bell peppers showed RT₂₅ within 9 days, with residues ranging from 1.00 to 45.10 mg/kg. Clothianidin foliar treatment displayed RT₂₅ within 10 days on alfalfa, with residues between 0.61 and 2.57 mg/kg. On bell peppers, RT₂₅ was within 28 days, with residues ranging from 0.13 to 2.85 mg/kg. Soil treatment with imidacloprid and clothianidin in alfalfa exhibited minimal impact on honey bees and residues of 0.05 to 0.37 mg/kg. However, in applied crops, imidacloprid showed RT₂₅ within 28 days and residues ranging from 4.47 to 130.43 mg/kg, while clothianidin exhibited RT₂₅ within 35 days and residues between 5.96 and 42.32 mg/kg. In conclusion, when comparing honey bee toxicity and foliar residues among crops, application crops had a more significant impact on honey bee mortality and higher residue levels compared to control crops. Moreover, soil treatment for application crops resulted in higher RT₂₅ and residue levels compared to foliar treatment. Therefore, to ensure pesticide safety and environmental sustainability, diverse research approaches considering different crops and application methods are necessary for the safety assessment of imidacloprid and clothianidin.