• Analytical Science and Technology
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• v.27 no.6
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• pp.347-351
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• 2014

This study determinated the polychlorinated dibenzo-${\rho}$-dioxins and dibenzofurans (PCDDs and DFs) in fly ash and bottom ash of industrial waste incinerators. Experimental results showed that average PCDDs and DFs concentrations in fly ash were 4.5063 and 13.004 ng-TEQ/g, and in bottom ash were 0.2367 and 0.0993 ng-TEQ/g, respectively. Predominant congener in TEQ of PCDDs/DFs from fly ash were 1,2,3,4,6,7,8-HpCDD, OCDD, 2,3,4,6,7,8-HxCDF, 2,3,4,7,8-PeCDF and in bottom ash were 1,2,3,7,8-PeCDD and 2,3,4,7,8-PeCDF.

• Molecular & Cellular Toxicology
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• v.2 no.3
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• pp.151-158
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• 2006

Khal was a synthetic congener of halocidin, a heterodimeric peptide consisting of 19 and 15 amino acid residues detected in Halocynthia aurantium. This compound was considered a candidate for the development of a novel peptide antibiotic. The genotoxicity of Khal was subjected to high throughput toxicity screening (HTTS) because they revealed strong antibacterial effects. Mouse lymphoma thymidine kinase ($tk^{+/-}$) gene assay (MOLY), single cell gel electrophoresis (Comet) assay and chromosomal aberration assay in mammalian cells and Ames reverse mutation assay in bacterial system were used as simplified, inexpensive, short-term in vitro screening tests in our laboratory. These compounds are not mutagenic in S. typhimurium TA98 and TA100 strains both in the presence and absence of metabolic activation. Before performing the comet assay, $IC_{20}$ of Khal was determined the concentration of $25.51\;{\mu}/mL\;and\;21.99\;{\mu}g/mL$ with and without S-9, respectively. In the comet assay, Khal was not induced DNA damage in mouse lymphoma cell line. Also, the mutation frequencies in the Khal-treated cultures were similar to the vehicle controls. It is suggests that Khal is non-mutagenic in MOLY assay. And no clastogenicity was observed in Khal-treated Chinese hamster lung cells. The results of this battery of assays indicate that Khal has no genotoxic potential in bacterial or mammalian cell systems. Therefore, we suggest that Khal, as the optimal candidates with both no genotoxic potential and antibacterial effects must be chosen.

• Analytical Science and Technology
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• v.13 no.6
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• pp.802-809
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• 2000

Concentrations of polychlorinated biphenyl congeners (PCBs) in samples collected from 43 kindss of water, 35 kinds of soil and 11 kinds of sediment in various place of Korea have been monitored using GC/MS/SIM analytical method. In our investigation, mean recoveries were $83.8{\pm}10.4%$ for water, $94.9{\pm}12.2%$ for soil and sediment samples and $80.2{\pm}8.7%$ for the spiked $^{13}C{_{12}}$-PCBs. Detection limits of PCBs for water, soil and sediment samples are 0.01 ng/ml and 0.05 ng/g. PCB congeners in water samples were not detected within quantitation limit, but trace amounts were detected in most of soil and sediment samples. The contamination level of PCBs in Korea was evaluated to be lower than in advanced countries like USA, Europe and Japan.

• Environmental Engineering Research
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• v.11 no.4
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• pp.217-231
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• 2006

The gas-phase formation of polychlorinated naphthalenes (PCNs) and dibenzofurans (PCDFs) was experimentally investigated by slow combustion of the three chlorophenols (CPs): 2-chlorophenol (2-CP), 3-chlorophenol (3-CP) and 4-chlorophenol (4-CP), in a laminar flow reactor over the range of 550 to $750^{\circ}C$ under oxidative condition. Contrary to the a priori hypothesis, different distributions of PCN isomers were produced from each CP. To explain the distributions of polychlorinated dibenzofuran (PCDF) and PCN congeners, a pathway is proposed that builds on published mechanisms of PCDF formation from chlorinated phenols and naphthalene formation from dihydrofulvalene. This pathway involves phenoxy radical coupling at unsubstituted ortho-carbon sites followed by CO elimination to produce dichloro-9, 10-dihydrofulvalene intermediates. Naphthalene products are formed by loss of H and/or Cl atoms and rearrangement. The degree of chlorination of naphthalene and dibenzofuran products decreased as temperature increased, and, on average, the naphthalene congeners were less chlorinated than the dibenzofuran congeners. PCDF isomers were found to be weakly dependent to temperature, suggesting that phenoxy radical coupling is a low activation energy process. Different PCN isomers, on the other hand, are formed by alternative fusion routes from the same phenoxy radical coupling intermediate. PCN isomer distributions were found to be more temperature sensitive, with selectivity to particular isomers decreasing with increasing temperature.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.8
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• pp.579-585
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• 2013

Persistent Organic Pollutants (POPs) are chemical substances which persist in the environment, bioaccumulate through the food web, and pose a risk of causing adverse effects to human health and the environment. POPs are thermally stable, highly lipophilic and water-insoluble compounds which can induce various toxic influences including immunotoxicty, carcinogenicity adverse effects on reproduction, development and endocrine fuctions. Polybrominated diphenyl ethers or PBDEs, are organobromine compounds that are used as flame retardant. Because of their toxicity and persistence, the industrial production of some PBDEs is restricted under the Stockholm Convention, a treaty to control and phase out major POPs. In this study, PBDEs was measured in various site of Sihwa industrial complex to investigate concentration distribution of POPs. The levels of PBDEs in house dust samples were 0.722~44.024 ng/g-dry. In PBDEs congener, BDE-209 was relatively higher in the all sites. The concentration of BDE-209 measured over 80.0% of total PBDEs. In various site, high molecular PBDEs homologues are measured higher than low molecular.

• YAKHAK HOEJI
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• v.46 no.4
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• pp.247-257
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• 2002

Persistent organochlorine pesticides and polychlorinated biphenyls (PCBs) have been used intensively in agriculture or industry for a long time. The occurrence of organochlorine pesticides and PCBs in the environment and subsequently in parts of the food chain, resulting in the intake of these compounds by man and animal. The measure of the levels of organochlorine pesticides and PCBs in tissues or blood of human populations are good markers in determining the extent of exposure and in the evaluating the hazards. So, most countriess have conducted initial monitoring programs to determine organochlorine pesticides and PCBs in human tissues. But a few report has been presented in Korea. In this study, $\alpha$-BHC, $\beta$-BHC, ${\gamma}$-BHC, $\delta$-BHC, p,p'-DDT, p,p'-DDD, p,p'-DDE, endrin, dieldein, aldrin and 7 marker PCBs (28, 52, 101, 118, 138, 153, 180) were determined in human blood, adipose tissue and liver tissues collected at autopsy of 10 men and 10 women, 13-79 year of age. Significant differences in the levels of organochlorine pesticides and PCBs between districts where they had lived were found in the following chemicals: total PCB in the blood : $\beta$-BHC, total BHC, p,p'-DDE and total DDT in the adipose tissue : p,p'-DDE, total DDT and PCB 118 in the liver. No significant difference was found in the levels of organochlorine pesticides and PCBs between sexes and ages. Though the levels of organochlorine pesticides and PCBs were relatively lower than that of other countries, we could know that organochlorine pesticides and PCBs have been widely distributed in Korean human body.

• Journal of Environmental Health Sciences
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• v.40 no.3
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• pp.215-224
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• 2014

Objective: This study was carried out in order to determine the depositional characteristics of pine needles, pine bark, and soil used as a passive air sampler (PAS) for atmospheric polybrominated diphenyl ethers (PBDEs). Methods: All three media were sampled from the same site. The PBDE concentrations were analyzed by HRGC/HRMS, and the lipid contents were measured using the gravimetric method by n-hexane extraction. Results: The total PBDE concentration was the highest in soil (22,274.57 pg/g dry), followed by pine bark (20,266.39 pg/g dry), and then pine needles (7,380.22 pg/g dry). Pine needles contained the highest lipid contents (21.31 mg/g dry), whereas soil (10.01 mg/g dry), and pine bark (4.85 mg/g dry) contained less. There were poor correlations between lipid content and total PBDE concentrations in the media ($R^2$=0.8216, p=0.2814). Congeners BDE 47, 99, 183, 196, 197, 206, 207 and 209 showed peak concentrations. Among these, BDE 206, 207, and 209 are highly brominated PBDEs that exist as particulates in ambient air. They accounted for 81.2% [69.2 (pine needles) - 89.0% (tree bark)] of the concentration and therefore are noted as the main congener of the total PBDEs. Conclusions: It can therefore be concluded that for reducing error by improper sampling, the same species of media should be recommended for use as a PAS for atmospheric PBDEs due to the differences in depositional characteristics.

• Journal of Environmental Science International
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• v.14 no.6
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• pp.583-596
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• 2005

Samples of water, soil, and sediment were taken from 10 streams of Andong city in Gyeongbuk province in October 2004. To assess the degree of environmental pollution for each stream site, the chemical analyses of pollutants such as T-N, T-P, COD, heavy metal, organophosphorous and organochlorine pesticides, and dioxin-like PCB congeners were implemented using the standard process tests or the U. S. EPA methods. In addition, biological assessment using insect immune biomarkers was conducted on the same environmental samples to complement the chemical assessment. Except Waya stream (T-N; 2.91 mg/L, T-P; 0.16 mg/L, COD; 14.0 mg/L) with above the environmental quality standards, the T-P and COD concentrations of 9 sites are relatively low. The contents of Pb and Cd in samples taken from each stream were much lower than environmental quality standards. However, in comparison with soil samples of other streams, several times higher concentrations of Pb and Cd were found in locations at Mi, Gilan, Yeonha, and Waya stream sites. Dementon-S-methyl, diazinon, parathion, and phenthoate compounds among organophosphorous pesticides were detected as concentrations of ppb levels, respectively, from soil samples collected in the vicinity of Gilan, Mi, Norim, and Waya stream. On the other hand, 16 organochlorine pesticides and 12 dioxin-like PCB congeners selected in this study were not found in all samples. In particular, considering significant disrupting effects of Waya stream's samples on insect immune capacity, this stream seems to be contaminated with investigated and/or univestigated pollutants in this study.

• Journal of Microbiology and Biotechnology
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• v.11 no.5
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• pp.763-771
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• 2001

Biphenyl dioxygenase (BPDO), which catalyzes the first step in the bacterial degradation of biphenyl and polychlorinated biphenyls, was characterized in Pseudomonas sp. B4. The bphA locus containing the four structural genes encoding BPDO were cloned and sequenced. A regulatory gene as well as a putative regulatory sequence were identified upstream of this locus. A transposase-like gene was found within a 1-kb region further upstream, thereby suggesting that the bphA locus may be carried on a transposable element. The three components of the BPDO enzyme have been separately overexpressed and purified from E. coli. The ferredoxin and terminal dioxygenase components showed biochemical properties comparable to those of two previously characterized BPDOs, whereas the ferredoxin reductase exhibited an unusually high lability. The substrate selectivity of BPDO was examined in vivo using resting cell assays performed with mixtures of selected polychlorinated biphenyls. The results indicated that para-substituted congeners were the preferred substrates. In vitro studies were carried out on a BPDO complex where the reductase from strain B4 we replaced by the more stable isoform from Comamonas testosteroni B-356. The BPDO enzyme had a specific activity of $0.26{\pm}0.02 {\mu}mol {min^-1}{mg^-1}\;of\;ISP_{BPH}$ with biphenyl as the substrate. The 2,3-, 4,4'-, and 2,4,4'-chlorobiphenyls were converted to single dihydrodiols, while 2,4'-dichlorobiphenyl gave rise to two dihydrodiols. The current data also indicated that 2,4,4'-trichlorobiphenyl was a better substrate than the 4,4'-dichlorinated congener.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.3
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• pp.208-216
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• 2009

This study was performed to investigate levels of POPs in soil by land use and identify congener profiles of PCBs, PCDD/Fs in soil in Korea. Heptachlor, Aldrin, Endrin, Mirex, Toxaphene were not found in all areas. The concentrations of Diedrin, Chlordane, ${\Sigma}$DDT, HCB in soil samples were in ranged from N.D. to 12.08 ${\mu}g$/kg, from N.D. to 16.08 ${\mu}g$/kg, from N.D. to 38.19 ${\mu}g$/kg and from N.D. to 1.32 ${\mu}g$/kg. In case of PCBs, concentration were in ranged from N.D. to 172.12 ${\mu}g$/kg, and PCBs contaminated area was higher than other areas. The concentrations of PCDD/Fs were in ranged from 0 to 6.68 pg I-TEQ/g. In addition, the ${\Sigma}$PCDFs concentration in the industry area soil was higher than ${\Sigma}$PCDDs.