• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.05a
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• pp.195-195
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• 2003

It is well known that diesel exhaust particulate matter contains mutagenic PAHs, such as benzo[${\alpha}$]pyrene, benz[${\alpha}$]anthracene, chrysene, etc. Therefore it is suspected that these chemicals act on estrogen receptor and reveal endocrine-disrupting effects. Recent attention has focused on causative chemicals of endocrine-disrupting effects. We examined the estrogenic activity of respirable diesel exhaust particulate matter derived from diesel powered vehicle. PM2.5 diesel exhaust of vehicle was collected using a high volume sampler equipped with a cascade impactor. Diesel exhaust samples were fractionated according to EPA methods. The presence of estrogenic and antiestrogenic chemicals in PM 2.5 diesel exhaust was determined using E-screen assay. To quantitatively assess the estrogenic and antiestrogenic activities in diesel exhaust particulate matter, estradiol equivalent concentration (bio-EEQ) was calculated by comparing the concentration response curve of the sample with those of the estrogen calibration curve. Weak estrogenic activities and strong antiestrogenic activities were detected in the crude extract and moderately polar fractions. Higher antiestrogenic potency was observed with higher EROD activities in aliphatic and aromatic compounds fraction. In conclusion, estrogenic/antiestrogenic-like activities were present in diesel exhaust particulate matter. However, the health consequences of this observation was unknown, the presence of these activities may contribute to and exacerbate adverse health effect evoked by diesel exhaust particulate matter.

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.4
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• pp.267-273
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• 2008

The purpose of this study is to investigate the distributive property of organic pollutants in effluents of argo/industrial wastewater treatment plants in Jeonnam using simultaneous analysis method of 310 chemicals. The numerous organic pollutants were detected in four sampling sites and the major chemicals were pesticides, CH type chemicals such as polycyclic compounds, CHO type chemicals such as phthalates, and CHO(N) type chemical such as aromatic amines. Moreover, 17 kinds of endocrine disrupters which include diethylptbalate were detected in each sampling sites. TU (Toxic unit) indicated cytotoxicity of samples using XTT assay, it appeared highly at A point(27.2) and D point(24.4). Also, the results from the correlation between total concentration of pollutants and TU did not correspond to the results of chemical and biological analysis.

• The Korean Journal of Pesticide Science
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• v.12 no.3
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• pp.295-301
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• 2008

Phenylformamidines are well known as insecticides for their specific activity against the insects. It has now been established that they show insecticidal activity as agonists on the octopamine receptor which is located in the synapse membrane. In this study we tried to test the effect of fluorine substituted aromatic formamidines and 1,3,5-triazapenta-1,4-dienes. Among the compounds, 2h, 2k, 21, 3g, 3h, 3k showed good activity against mite and aphid and 4f and 4g showed high activity against mite.

• Microbiology and Biotechnology Letters
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• v.37 no.3
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• pp.243-247
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• 2009

The usage of ethanol (EtOH)-blended gasoline (gasohol), has been increasing in recent years. EtOH has influence on the distribution and biodegradation of aromatic compounds such as BTEX (benzene (B), toluene (T), ethylbenzene (B), and xylene (X)) that are gasoline compositions. In this study, the effect of EtOH on the aerobic biodegradation of B, T and E was investigated using a BTEX and EtOH-degrading bacterium, Rhodococcus sp. EH831. The degradation rates of B in the conditions of 1:1, 1:4, and 1:0.25 mixtures with EtOH (B:EtOH, mol:mol) were ranged from $3.82{\pm}0.20$ to $5.00{\pm}0.37{\mu}mol{\cdot}g-dry$ cell wight $(DCW)^{-1}{\cdot}h^{-1}$. The degradation rate of T was the fastest in the 1:0.25 mixture ($6.63{\pm}0.06{\mu}mol{\cdot}g-DCW^{-1}{\cdot}h^{-1}$), and it was the lowest in the 1:4 mixture ($4.41{\pm}0.04{\mu}mol{\cdot}DCW^{-1}{\cdot}h^{-1}$). The degradation rates of E were increased with increasing the addition amount of EtOH: The degradation rate of E was the highest in the 1:4 mixture ($1.60{\pm}0.03{\mu}mol{\cdot}g-DCW^{-1}{\cdot}h^{-1}$), and the rates were $1.42{\pm}0.06$, $1.30{\pm}0.01$, and $1.01{\pm}0.30{\mu}mol{\cdot}g-DCW^{-1}{\cdot}h^{-1}$ in the 1:1, 1:0.25, 1.0 mixtures, respectively. In conclusion, the biodegradation of B, T, E by Rhodococcus sp. EH831 was not significantly inhibited by the co-existence of EtOH.

• Journal of Environmental Science International
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• v.16 no.4
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• pp.415-423
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• 2007

This study assessed the characteristic of BTEX (Benzene, Toluene, Ethylbenzene, Xylene) concentration ratios of industrial emission sources and the neighborhoods of industrial area, fuel such as gasoline, light oil, LPG, and similar gasoline, and ambient air in Daegu. The BTEX in aromatic compounds was the most abundant VOC in Daegu. The BTEX ratios were (0.2:2.6:1.0:1.8) for the neighborhoods of industrial area, (2.6:11.3:1.0:1.2) for residential area, (2.2:11.0:1.0:1.6) for commercial area, (1.0:14.9:1.0:1.3) for industrial area, and (0.2:2.6:1.0:1.8) for the neighborhoods of industrial area. Average BTEX ratios in Daegu were B/T ratio (0.1), B/EB ratio (1.5), B/X ratio (1.1), T/EB ratio (12.6), T/X ratio (10), EB/X ratio (0.7), Expecially, B/T ratio in Daegu was similar as the other cities, Bangkok, Manila, and Hongkong. Comparing other cities with B/T ratio, the main sources of VOC were vehicular exhaust and emission of industrial facilities. Furthermore, BTEX correlation were evaluated at the emission sources and regional areas. Results showed that correlation coefficient values of emission sources, fuels and neighborhood of industry were significant magnitude above 0.65(p<0.01). Also, there showed highly significant correlations among BTEX. Calculated correlation coefficients of ambient air sampling sites were $0.61{\sim}0.954$ for commercial /residential area and $0.613{\sim}0.998$ for industrial area. However, they showed different correlation between commercial/residental area and industrial area. It implied that the emission sources were different from each area.

• Journal of Forest and Environmental Science
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• v.33 no.2
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• pp.113-121
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• 2017

In flight particulate matter particularly emissions generated by incomplete combustion processes has become a subject of global concern due to the health problems and environmental impacts associated with them. This has compelled most countries to set standards for coarse and fine particles due to their conspicuous impacts on environment and public health. This contribution therefore explores forest fire emissions and how its particulates affects air quality, damage to vegetation, water bodies and biological functions as architects for lung diseases and other degenerative illnesses such as oxidative stress and aging. Soot was collected from simulated forest fire using a clean glass surface and carefully transferred into amber vials for analysis. Volatile components of soot were collected over 10 mL dichloromethane and analyzed using a QTOF Premier-Water Corp Liquid Chromatography hyphenated to a mass selective detector (MSD), and Gas Chromatograph coupled to a mass spectrometer (GC-MS). To characterize the size and surface morphology of soot, a scanning electron microscope (SEM) was used. The characterization of molecular volatiles from simulated forest fire emissions revealed long chain compounds including octadec-9-enoic acid, octadec-6-enoic acid, cyclotetracosane, cyclotetradecane, and a few aromatic hydrocarbons (benzene and naphthalene). Special classes of organics (dibenzo-p-dioxin and 2H-benzopyran) were also detected as minor products. Dibenzo-p-dioxin for instance in chlorinated form is one of the deadliest environmental organic toxins. The average particulate size of emissions using SEM was found to be $11.51{\pm}4.91{\mu}m$. This study has shown that most of the emissions from simulated forest fire fall within $PM_{10}$ particulate size. The molecular by-products of forest fire and particulate emissions may be toxic to both human and natural ecosystems, and are possible precursors for various respiratory ailments and cancers. The burning of a forest by natural disasters or man-made fires results in the destruction of natural habitats and serious air pollution.

• BMB Reports
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• v.35 no.4
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• pp.432-436
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• 2002

Pseudomonas sp. S-47 is capable of degrading catechol and 4-chlorocatechol via the meta-cleavage pathway. XyITE products catalyze the dioxygenation of the aromatics. The sylT of the strain S-47 is located just upstream of the xylE gene. XylT of the strain S-47 is located just upstream of the xylE gene. XyIT is typical chloroplast-type ferredoxin, which is characterized by 4 cystein residues that are located at positions 41, 46, 49, and 81. The chloroplast-type ferredoxin of Pseudomonas sp. S-47 exhibited a 98% identity with that of P. putida mt-2(TOL plasmid) in the amino acid sequence, but only about a 40 to 60% identity with the corresponding enzymes from other organisms. We constructed two recombinant plasmids (pRES1 containing xylTE and pRES101 containing xylE without xylT) in order to examine the function of XyIT for the reactivation of the catechol 2,3-dioxygenase (XyIE) that is oxidized with hydrogen peroxide was recovered in the catechol 2,3-dioxygenase (C23O) activity about 4 mimutes after incubation, but the pRES101 showed no recovery. That means that the typical chloroplast-type ferredoxin (XyIT) of Pseudomonas sp. S-47 is involved in the reactivation of the oxidized C23O in the dioxygenolytic cleavage of aromatic compounds.

• Journal of the Korean Chemical Society
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• v.24 no.4
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• pp.280-287
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• 1980

The interactions of chemical carcinogens, such as polycyclic aromatic hydrocarbons, dimethylaminoazobenzene (DAB) and its derivatives and heterocyclic compounds with tissue components, especially with deoxyribonucleic acid (DNA), were examined by means of simple Huckel method. Assuming that the formations of a loose molecular complex between the carcinogens and the tissue components are the first step of chemical carcinogenesis, the most proble orientation between the chemical carcinogens and adenine-thymine (A=T) pair or guanine-cytosine $(G\equivC)$ pair is determined. It has been found that, in the case of the formation of molecular complex between chemical carcinogens and A=T pair, the two atoms of K-region of the carcinogens and the atom of L-region in the proximity of their K-region are combined correspondingly with C-l' carbon atom in the sugar that is attached to thymine, N-1 nitrogen atom and C-5 carbon atom in the thymine part of A=T pair, while, in the case of that between the carcinogens and $G\equivC$ pair, the above three atoms of the carcinogens are combined correspondingly with C-8 carbon atom, N-9 nitrogen atom and N-3 nitrogen atom in the guanine part of $G\equivC$ pair.

• Journal of Korean Society on Water Environment
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• v.24 no.6
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• pp.682-689
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• 2008

The purpose of this study was to find out the variation between molecular size distribution (MSD) of natural organic matter (NOM) in raw waters after different water treatment processes like conventional process (coagulation, flocculation, filtration) followed by advanced oxidation process (ozonation, GAC adsorption). The MSD of NOM of Suji pilot plant were determined by Liquid Chromatography-Organic Carbon Detection (LC-OCD) which is a kine of high-performance size-exclusion chromatography (HPSEC) with nondispersive infrared (NDIR) detector and $UV_{254}$ detector. Five distinct fractions were generally separated from water samples with the Toyopearl HW-50S column, using 28 mmol phosphate buffer at pH 6.58 as an eluent. Large and intermediate humic fractions were the most dominant fractions in surface water. High molecular weight (HMW) matter was clearly easier to remove in coagulation and clarification than low molecular weight (LMW) matter. Water treatment processes removed the two largest fractions almost completely shifting the MSD towards smaller molecular size in DW. No more distinct variation of MSD was observed by ozone process after sand filtration but the SUVA value were obviously reduced during increase of the ozone doses. UVD results and HS-Diagram demonstrate that ozone induce not the variation of molecular size of humic substance but change the bond structure from aromatic rings or double bonds to single bond. Granular activated carbon (GAC) filtration removed 8~9% of organic compounds and showed better adsorption property for small MSD than large one.

• International Journal of Safety
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• v.4 no.1
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• pp.14-17
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• 2005

Recycled polyol was obtained by glycolysis of MDI-based Polyurethane(PU) rigid foam. The chemical structure of the recycled pclyol was confirmed by GC(gas chromatography) and 1H-NMR. The recycled polyol throughout the glycolysis contained liquid polyol and methylenedianiline(MDA). MDA which could cause liver cancer is carcinogenic material. TWA(Time Weighted Average.) amount for MDA in MSDS(Material Safety Data Sheets) was confined less than 0.1 ppm. The melting temperature of MDA is $92^{\circ}C$, and boiling temperature is $398^{\circ}C$. During the gylcolysis most of MDA was dissolved in liquid polyol. The probability that MDA diffuses into the atmosphere is low but there could be an absorption of MDA into skin. Furthermore because MDA is amine compound, recycled polyol which contained MDA had a difficulty in reaction control of polyurethane. Therefore reduction of MDA amount was needed strongly. In this study the elimination of MDA were performed through deamination of the recycled polyol by glycidyl ether compounds. As glycolysis was proceeded, the amount of MDA was 9.8 wt % at early stage and increased up to 14.0 wt % after 8 hours reaction. It was found that 2-Ethylhexyl glycidyl ether which contains aliphatic moiety was very effective compound for eliminating the primary aromatic amine compound :md the optimal mole ratio of 2-ethylhexyl glycidyl ether to MAD was 3. The final polyol after deamination by 2-ethylhexyl glycidyl ether has an appropriate viscosity(less than 500 centi poise) for polyurethane reaction.