• The Korean Journal of Physiology and Pharmacology
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• v.9 no.1
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• pp.9-15
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• 2005

We attempted to analyze the mechanism of polychlorinated biphenyl (PCB)-induced neurotoxicity and identify the target molecules in the neuronal cells for PCBs.Since the developing neuron is particularly sensitive to PCB-induced neurotoxicity, we isolated cerebellar granule cells derived from 7-day old Sprague Dawley (SD) rats and grew cells in culture for additional 7 days to mimic PND-14 conditions. Only non-coplanar PCBs at a high dose showed a significant increase of total protein kinase C (PKC) activity at phobol 12,13-dibutyrate ([$^3M$]PDBu) binding assay, indicating that non-coplanar PCBs are more neuroactive than coplanar PCBs in neuronal cells. PKC isozymes were immunoblotted with the selected monoclonal antibodies. PKC-${\alpha}$, ${\delta}$, and ε were activated with non-coplanar PCB exposure. Receptor for activated C kinase-1 (RACK-1), anchoring protein for activated PKC, was more induced with exposure to coplanar PCBs than non-coplanar PCBs. Reverse transcription PCR (RT-PCR) analysis showed induction of neurogranin (RC-3) and growth associated protein-43 (GAP-43) mRNA with non-coplanar PCBs. The results indicate that these factors may be useful biomarkers for differentiating non-coplanar PCBs from coplanar PCBs. The present study demonstrated that non-coplanar PCBs are more neuroactive congeners than coplanar PCBs.

• Environmental Analysis Health and Toxicology
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• v.22 no.3
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• pp.279-285
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• 2007

The present study attempted to analyze the mechanism of PCB-induced neurotoxicity with respect to the PKC signaling. Since the developing neuron is particularly sensitive to PCB-induced neurotoxicity, we isolated cerebellar granule cells derived from 7-day old SD rats and grew cells in culture for additional 7 days to mimic PND-14 conditions. Only non-coplanar PCBs at a high dose showed a significant increase of total PKC activity at $[^3H]PDBu$ binding assay, indicating that non-coplanar PCBs are more neuroactive than coplanar PCBs in neuronal cells. PKC isoforms were immunoblotted with respective monoclonal antibodies. PKC-alpha and-epsilon were activated with non-coplanar PCB exposure. The result suggests that coplanar PCBs have a PKC pathway different from non-coplanar PCBs. Activation of PKC with exposure was dampened with treatment of high molecular weight of chitosan. Chilean (M.W. > 1,000 kDa) inhibited the total activity of PKC induced by the non-coplanar PCBs. Translocation of PKC isoforms was also inhibited by the high molecular weight of chitosan. The study demonstrated that non-coplanar PCBs are more potent neurotoxic congeners than coplanar PCBs and the alteration of PKC activities by PCB exposure can be blocked with the treatment of chitosan. The results suggest a potential use of chitosan as a means of nutritional intervention to prevent the harmful effects of pollutant-derived diseases.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.6
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• pp.734-743
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• 2007

Polyurethane foam-disk passive air samplers (PAS) were deployed in a southern area of Korea for three months. The target compounds were 12 coplanar polychlorinated biphenyls (PCBs). The congener profiles measured in this study were the same as those in ambient air and emission gas from the incinerator. A gradient of the total PCBs in different regions (industrial>residential>rural) was observed, suggesting the industrial complex may be an important source of coplanar PCBs. In general, only gas-phase compounds are mainly sequestrated by PAS. In order to estimate the concentration of particle-phase PCBs, a gas/particle partition model was used. A combined result (gas+particle-phase PCBs) was compared with previous results, indicating that the level of coplanar PCBs in our study area is comparable to those in other urban sites in the world. The validation of this method for estimating the total concentration is required through additional backup studies.

• Journal of the Korean Chemical Society
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• v.41 no.5
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• pp.239-245
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• 1997

The sorption kinetic was studied to evaluate feasibility of removing PCBs from mineral oil with activated carbon. Adsorption efficiency for Aroclor 1242 which is composed of lower chlorinated PCB formulations was $\geq$ 95%, whereas the adsorption efficiency for Aroclor 1260 having higher chlorinated constituents was considerably lower with the efficiency falling to 75%. The observed difference in the adsorption efficiency is attributed to the geometry of PCBs with non-planar and coplanar structure. The concentration of coplanar PCBs is appreciably higher in Aroclor 1242. Since toxicity is primarily associated with coplanar congeners, the preferential adsorption of coplanar congeners by activated carbon accounts for the fact that toxicity reduction can be achieved through this process. The efficiency of process was assessed in terms of Toxicity Equivalence Factor (TEF).

• Toxicological Research
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• v.22 no.1
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• pp.23-30
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• 2006

Among poly aromatic hydrocarbons, dioxin and PCBs are the most controversial environmental pollutants in our modern life. These pollutants are known as human carcinogens, and liver is the most sensitive target in animal cancer models. Specific aims of the study were focused on the mechanism of carcinogenesis in hepatocytes and the structure-activity relation among these diverse environmental chemicals. Because key mechanisms of dioxin-induced carcinogenesis in human epithelial cell model are the alteration of signal transduction pathway and PKC isoforms, the alteration of the signal transduction pathways and other factors associated with carcinogenesis were studied. Rat hepatocytes cultured under the sandwich protocols were exposed with the various concentration of dioxins and PCBs, and signal transduction pathway, protein kinase C isoforms, oxidant stress, and apoptotic nuclei were evaluated. Since it is important to understand the structure-activity relation among these chemicals to properly assess the carcinogenic potentials, the study analyzed the parameters associated with carcinogenic processes, based on their structural characteristics. In addition, signal transduction pathways and PKC isoforms involved in inhibition of UV-induced apoptosis were also analyzed to elaborate the tumor promotion mechanism of these chemicals. Induction of apoptosis by UV irradiation was optimal at $60\;J/m^2$ in primary hepatocyte in culture. Compared to non coplanar PCBs such as PCB 114 and PCB 153, coplanar PCBs such as PCB 77 and PCB126 showed a stronger inhibition of apoptosis induced by UV irradiation. Production of reactive oxygen species (ROS) was more stimulated by non-coplanar PCBs than coplanar PCBs with the most potent induction of ROS by chlorinated non-coplanar PCB. As compared to the level of induction by PCB126, non-coplanar PCB153 showed a higher increase of intracellular concentrations. Besides the alteration of intracellular calcium concentration, translocation of PKC from cytosolic fraction to membrane fraction was clearly observed upon the exposure of non-coplanar PCB. Taken together, the present study demonstrated that there is a potent structure-activity relationship among PCB congeners and the mechanism of PAH-induced carcinogenesis is structure-specific. The study suggested that more diverse pathways of PAH-induced carcinogenesis should be taken into account beyond the boundary of Ah receptor dogma to assess the health impact of PAH with more accuracy.

• Korean Journal of Environmental Biology
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• v.26 no.4
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• pp.330-342
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• 2008

A comprehensive quality survey for PCDDs/PCDFs and coplanar PCBs as well as heavy metals (Cu, Zn, Cd and Pb) in sediments has been investigated in August 2006, Korea. Monitoring was undertaken at five streams representing different surrounding environments throughout Juwang and Gapyeong streams (reference sites), Jungrang stream (dense population site), Ansan stream (mixed small population and industrial site), and Siheung stream (heavy industrial site). The levels of heavy metal in samples were found to be significantly higher in sediment from Siheung stream compared to those of other stream sites. The heavy metal concentrations (dry weight basis) in sediment from Siheung stream were as follows; Cd (3.7 ${\mu}g$/g), Pb (1,295 ${\mu}g$/g), Cu (713.4 ${\mu}g$/g) and Zn (358.1 ${\mu}g$/g). Among 12 coplanar PCBs and 17 PCDDs/PCDFs selected as target compounds in this study, PCB (IUPAC no. 118) and OCDD were the most abundant congeners found in all sediment samples, followed by 1,2,3,4,6,7,8-HpCDD, OCDF and 1,2,3,4,6,7,8HpCDF as well as PCB (IUPAC no. 105). These results were shown to be in the same trend as the sediment samples of other countries. The levels of PCDDs/PCDFs/coplanar PCBs in sediment samples were expressed as concentrations and WHO- TEQ values. The PCDDs/PCDFs/coplanar PCBs concentrations and their WHO-TEQ values in sediment from Siheung stream were remarkably high. The levels detected were 788.16 pg/g and 36.080 pg WHO-TEQ/g dry weight for PCDDs/ PCDFs and 314 pg/g and 0.4189 pg WHO-TEQ/g dry weight for coplanar PCBs, respectively, beyond the safety level of sediment value 20 pg WHO-TEQ/g. Sediment samples of the five streams were also monitored by sensitive biomarkers using insect immune responses: hemocyte-spreading behavior and immune-associated enzyme activities of phospholipase A$_2$ (PLA$_2$) and phenoloxidase. Organic extracts of Siheung and Jungrang sediments significantly interfered with the hemocytespreading behavior, whereas those of Ansan, Gapyeong, and Juwang did not. These organic extracts did not inhibit the PLA$_2$ and phenoloxidase activities. However, phenoloxidase was highly susceptible to exposure to aqueous extracts in all site sediments. In comparison, PLA$_2$ activities of the hemocytes were significantly inhibited only by aqueous extracts of Siheung, Jungrang, and Gapyeong sediments, but not by those of Ansan and Juwang. Despite some disparity between bioand chemical monitoring results, the biomarkers can be recommended as a device warning the contamination of biohazard environmental chemicals because of a fast and inexpensive detection method.

• Analytical Science and Technology
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• v.15 no.5
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• pp.466-474
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• 2002

The analytical method of 14 kinds of coplanar - PCBs was established and applied the soil sample. The three kinds of extraction solvents (toluene, acetone: n-hexane, dichloromethane) were selected to apply the soil sample. The silica gel, florisil and alumina column cleanup also performed to compare the elution recovery. The average recovery of selected solvents in soil A, B and C was surveyed the 84.25%, 56.09% and 44.69% for toluene, 52.56%, 81.42% and 58.53% for acetone : n - hexane and 55.94%, 71.33% and 61.05% for dichloromethane. The average recovery is represented 49.99% for silica gel (n - hexane 100 mL), 69.65% for florisil (6% ether/n - hexane 100 mL), and 65.23% for alumina (2% DCM : n - hexane 100 mL, 50% DCM: n-hexane 150 mL). In silica gel (n - hexane) and florisil (6% ether : n - hexane) cleanup, the 14 kinds of coplanar PCBs eluted until 40 mL. In the silica gel and florisil columns cleanup, the amounts of elution solvent can be reduced from these results, but the researcher has to confirm the elution amounts before performing the experiments. In alumina cleanup process, the result was obtained to the 100 mL of elution solvents (2% DCM: n-hexane 100 mL and 50% DCM: n-hexane 40 mL), therefore the change of elution solvent is necessary to develop the simple procedure.

• Analytical Science and Technology
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• v.16 no.4
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• pp.309-319
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• 2003

This study was performed to describe analysis method of 209 PCB congeners in ambient air samples. The samples were collected by high volume air sampler in Chonju city. Extracted samples were cleaned by silicagel cleanup modified with sulfuric acid and activated carbon cleanup processing. The cleaned samples were analyzed by high resolution gas chromatography and high resolution mass spectrometry (HRGC/HRMS) with DB-5 column (60 m, 0.25 mm i.d., 0.25 m film thickness) to analyze the 209 kinds of PCB congeners. PCBs levels of air samples were detected to the range between 0.003 and $0.163pg-TEQ/m^3$. The PCBs congener of 162 kinds were detected in samples analysed using DB-5 column and 37 kinds peaks were overlapped with congeners more than one. It is difficult to isolate PCB 118/106 and PCB 105/127 in coplanar PCB, so it is likely to overestimate the concentration.. The distribution of coplanar-PCB congeners in origin source samples (Kanechlor and exhaust gas from incinerator) was compared with that in air samples, and PCB 81, PCB 77, PCB 126, and PCB 169 were higher in incinerator samples.

• Analytical Science and Technology
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• v.16 no.1
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• pp.48-58
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• 2003

The effects of physico-chemical properties of soils on PCBs analysis in Korea was studied Three kinds of extraction solvents(toluene, acetone:hexane, dichloromethane) was selected to apply three different soils. The silicagel, florisil and alumina column cleanup also performed to compare the elution patterns, and three different methods (EPA, Japan, Proposed method in this study) of 62 PCBs also compared the individual peaks recoveries. The solvent average recovery was surveyed the order of toluene, acetone:hexane, dichloromethane as 77.94%, 58.59%, 54.20% for soil A, 53.65%, 80.32%, 68.27% for soil B and 44.52%, 60.35%, 56.36% for soil C, respectively. The average recovery was depended on the soil characters. The highest recoveries of each soil were obtained the toluene for soil A, acetone:hexane for soil B and C. However, the coplanar PCBs was obtained the highest recovery with dichloromethane. Thus, to select the solvent for the analysis of PCBs in solid, the selected compounds have to consider to get good result. The silicagel, florisil, alumina I and alumina II column cleanup process were surveyed the range of 38.73%~98.26%, and the higher chlorinated compounds was obtained the lower recovery compared to the low chlorinated compounds, generally. This results are also consistent with the coplanar PCBs isomers. The compared results of three different countries were obtained the 37.15% for USA, 45.92% for Japan and 44.46% for proposed method in this study.

• Journal of Environmental Science International
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• v.17 no.3
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• pp.287-296
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• 2008

A comprehensive quality survey for heavy metals, organophosphorous and organochlorine residual pesticides, and coplanar PCBs in samples such as water, sediments and soils as well as spiders has been implemented. The samples were undertaken at nine stream sites and their vicinity in August 2006, representing different surrounding environments. The levels of PCBs were expressed as concentrations and WHO-TEFs. Among 12 coplanar PCBs as target compounds in this study, 2,3', 4,4', 5-PentaCB (IUPAC # 118) was the congener with the highest concentration. The total concentrations and TEF values of coplanar PCBs in Siheung stream sediment (heavy industrial complex site located in Ansan city) were 3915.50 pg/g and 0.8366 pg-TEQ/g on a dry weight basis, respectively. Such levels were around 40 times higher compared to sediment from Gapyung stream (green site located in the upper of Myunggi mountain). It is probably due to the direct input of PCBs trom PCBs treatment materials. Organophosphorous (EPN, dementon-s-methyl, diazinon, parathion, and phenthoate) and organochlorine (alpha-BHC, aldrin, 4,4'-DDT, 4,4'-DDE, endosulfan alpha and etc.) pesticides were not detected above 5 ppb of detection limits. The concentrations of Cu and Cd in water and sediment samples from Siheung stream were 44.11 and $0.17ug/m\ell$ and $713.42{\mu}g/g$ and $3.73{\mu}g/g$, respectively, which contained $20\sim40$ times higher concentrations than those from Gapyung stream. In addition to the water and sediment samples, the levels of heavy metals in spider from designated sampling sites were also determined. Heavy metals in spider collected near Siheung stream was appeared to be equivalent and/or a little higher levels with respect to other spiders. Furthermore, the ratio of relative heavy metals (Cu, Cd, and Pb) in spider from each stream site showed a correlation as similar as that of heavy metals in soil samples.