• The Korean Journal of Pesticide Science
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• v.14 no.1
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• pp.10-15
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• 2010

Most pesticides are poorly soluble in water and must be dissolved in a solvent carrier before being added to the test medium on aquatic toxicity test. The concentration of solvent is critical to the success of a test. This study were conducted to recommend possible organic solvents which have good solubility for pesticides and low toxicity to Korean native water flea to establish new standard toxicity test methods using Korean native water flea for ecological risk assessment of pesticide. Four Korean freshwater cladocerans, Daphnia obtusa, Daphnia sp., Moina macrocopa and Simocephalus vetulus were exposed to 10 different organic solvents during 48 hours to evaluate their toxic response to solvents. Ethyl acetate was the most toxic to cladocerans tested. Although ethyl ether was the least toxic to cladocerans tested, it may not adequate as possible solvent in aquatic toxicity test due to high volatility and low water solubility. In conclusion, acetone, methanol, ethanol and acetonitrile which has low toxicity as well as good water solubility are recommended as optimal organic solvent to use in aquatic toxicity tests with Korean native cladocerans tested.

• Toxicological Research
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• v.24 no.3
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• pp.161-167
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• 2008

Recently, arsenic-toxicity has become the major focus of strenuous assessment and dynamic research from the academy and regulatory agency. To elucidate the cause and the mechanism underlying the serious adverse health effects from chronic ingestion of arsenic-contaminated drinking water, numerous studies have been directed on the investigation of arsenic-toxicity using various in vitro as well as in vivo systems. Neverthless, some questions for arsenic effects remain unexplained, reflecting the contribution of unknown factors to the manifestation of arsenic-toxicity. Interestingly, very recent studies on arsenic metabolites have discovered that trivalent methylated arsenicals show stronger cytotoxic and genotoxic potentials than inorganic arsenic or pentavalent metabolites, arguing that these metabolites could play a key role in arsenic-associated disorders. In this review, recent progress and literatures are summarized on the metabolism of trivalent methylated metabolites and their toxicity on body systems including cardiovascular system in an effort to provide an insight into the future research on arsenic-associated disorders.

• Herbal Formula Science
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• v.19 no.2
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• pp.93-108
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• 2011

Objectives : Angelica sinensis has been used extensively in Korean traditional medicine. Although thorough clinical trials are lacking, Various pharmacological actions for Angelica sinensis has been identified newly using animal models. In addition, it was reported that reactive intermediates, potentially causing toxic effects, was isolated from components in Angelica sinensis. In this article, it was purposed for explanation and introduction of new studies for Angelica sinensis. in terms of Pharmacological action and Toxicity. Methods : New studies for Angelica sinensis were reviewed and summarized in terms of pharmacological action and toxicity. Results and Conclusions : Angelica sinensis and its components including phthalide, phthalide dimers, polysaccharides, polyacetylenes, ligustilide와 butylidenephthalide as well as organic acid showed a variety of pharmacological actions on uterine, cardiovascular system and immune system. In addition, it was identified that three components of such as ligustilide, caffeic acid and safrole was biotransformed to reactive intermediates causing possibly toxicity.

• Journal of Life Science
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• v.25 no.12
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• pp.1458-1469
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• 2015

Many organic solvent-tolerant bacteria have been isolated from all environments such as soil, waste-water, even deep sea after first isolation report of organic solvent-tolerant bacterium. Most organic solvent- tolerant isolates have been determined to be Gram-negative bacteria, because Gram-negative bacteria have inherent tolerance property toward hostile organic solvents more than Gram-positive bacteria. The mechanisms of organic solvent tolerance have been elucidated extensively using mainly organic solvent-tolerant Gram-negative bacteria. The solvent-tolerance mechanisms in Gram-positive bacteria can be found in comparatively recent research. Organic solvents exhibited different toxicity depending on the solvent, and the tolerance levels of organic solvent-tolerant bacteria toward organic solvents were also highly changeable among species and strains. Therefore, organic solvent-tolerant bacteria could coped with solvent toxicity and adapted to solvent stress through the multifactorial and multigenic adaptative strategies. They could be survived even in the hyper concentrations of organic solvents by mechanisms which include: changes in cell morphology and cell behaviour, cell surface modifications, cell membrane adaptations, solvent excretion pumps, chaperones and anti-oxidative response. The aim of this work is to review the representative solvent tolerant bacteria and the adaptative and tolerance strategies toward organic solvents in organic solvent-tolerant bacteria, and their potential industrial and environmental impact.

• The Korean Journal of Pesticide Science
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• v.4 no.4
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• pp.48-55
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• 2000

This study examined how does farm producers and urban consumers recognize the toxicity of pesticides application to agricultural production. The survey was carried out with quesuonnaires, and found tile fellowing results. The 60% of the total respondents in urban residents acknowledged that it is necessary for farming to apply pesticides. Nevertheless, they think that pesticides application have excessively been done more than necessary, and they would cause the problem of agrochemical-residual in agricultural products. They preferred to the crops produced by organic-farming. But they do not believe that the organic crops are pure one that pesticides are not applied at all. They thought that pesticides remained in the crops and they cause a chronic toxicity and cancer, though their degree of causing cancer would not be high. The other hand, farmers among the total respondents expressed that pesticides are absolutely needed to farming. However, about half of the total farmers' respondents did not follow the recommended guide line for proper use of pesticides and applied its double amount of the recommended dose. The most of farmers thought that the applied pesticides would be persisted into the crops. The 69 % of the total respondents did not know that crops over MRL(Maximum Residue Limit) of pesticides must be discarded and tile farmer who distributed the crops over MRL of pesticides have to pay some kind of penalty.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.11
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• pp.1087-1094
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• 2008

Diazinon is a phosphorothiate insecticide widely used in the world including Korea. This study investigates the feasibility of photolysis and photocatalysis processes for the degradation of diazinon in water. Both photolysis and photocatalysis reactiosn were effective in degrdading diazinon, however lower TOC removals were achieved. In case of photocatalysis, approximately 40% of nitrogen from diazinon was recovered as NO$_3^-$, and less than 5% of phosphorus as PO$_4{^{3-}}$. However, the sulfur in diazinon molecule was completely recovered to SO$_4{^{2-}}$ from photocatalysis reaction, and the recovery from photolysis was 50%, indicating that P=S bond easily breaks first during photolysis and photocatalysis. The poor recoveries of ionic byproducts and TOC from photolysis and photocatalysis indicate the presence of other organic intermediates during reactions. The formation of organic intermediates were identified during reactions using GC/MS and LC/MS/MS, and the main degradation products were diazoxon, and 2-isopropyl-4-methyl-6-hydroxypyrimidine (IMP), respectively. Finally, the acute 48-hr toxicity test using Daphnia magna were employed to measure the toxicity reduction during photocatalysis of degradation. The results showed that the toxicity increased until 180 min of the photocatalysis reaction (from EC$_{50}$ (%) of 69.6 to 13.2%), however, acute toxicity completely disappeared (>100%) after 360 min. The toxicity results showed that the intermediates from photocatalysis such as diazoxon were more toxic than diazinon itself, however these intermediates can be degraded or mineralized with further reaction.

• Proceedings of the Korean Society of Soil Zoology Conference
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• 2005.09a
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• pp.25-25
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• 2005

• Journal of the Korean Society of Tobacco Science
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• v.12 no.2
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• pp.85-90
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• 1990

Pot experiment was conducted to find out the effect of decomposing degree of rice straw on growth characteristics of flue-cured tobacco, NC82. Tobacco growth was hindered by fresh straw of rice application. Generally, it was known that if organic matter of high Carbon/Nitrogen ratio had applied in soil, there was temporary nitrogen deficiency in plant caused by soil microorganism utilized nitrogen contained organic matter. In pot experiment, it was supposed that tobacco growth hindered by fresh straw of rice application was not nitrogen deficiency by soil microorganism, but gas toxicity by fresh straw of rice application.

• YAKHAK HOEJI
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• v.31 no.4
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• pp.236-251
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• 1987

The chemistry, antimicrobial properties, organic soil resistance, toxicity, corrosivity and chemical stability of stabilized alkaline 2%, glutaraldehyde solution(SGS) are discussed. SGS retains the maximum antimicrobial activity of alkaline glutaraldehyde solutions and the chemical stability here to fore observed only with acidic glutaraldehyde solutions. These improvements, along with the inherent resistance of glutaradehyde to neutralization by organic soil, allow SGS to be continuously used for 14 days in situations of high dilution, or 28 days in situations of low dilution.

• Molecular & Cellular Toxicology
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• v.3 no.2
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• pp.113-118
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• 2007

Chlorobenzenes due to their acute toxicity and the capability of bioaccumulating are of great health and environmental concern. Especially, 1, 2-dichlorobenzene (CAS No. 95-50-1) is used for organic synthesis, dye manufacture, as a solvent and for other applications in chemical industry. Adverse effects of 1, 2-dichlorobenzene includes increases in liver and kidney weights and hepatotoxicity. In this study, we evaluated the genetic toxicity of 1, 2-dichlorobenzene with more advanced methods, in vitro mouse lymphoma assay $tk^{+/-}$ gene assay (MLA) and in vitro mouse supravital micronucleus (MN) assay. 1, 2-Dichlorobenzene appeared the significantly positive results and the induction of large mutant colonies only in the presence of metabolic activation system with MLA. But in vitro testing of 1, 2-dichlorobenzene yielded negative results with supravital MN assay. These results suggest that 1, 2-dichlorobenzene may play a mutagen rather than clastogen in vitro mammalian system.