• Fisheries and Aquatic Sciences
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• v.10 no.2
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• pp.93-101
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• 2007

Concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were determined in marine sediments from Mokpo coastal water of Korea. Total and toxic equivalent (TEQ) concentrations of PCDD/Fs ranged from 19.4 to 175pg/g dry weight and ranged from 0.195 to 2.87 pg WHO-TEQ/g dry weight, respectively. These PCDD/F concentrations were below the safety sediment value (20 pg TEQ/g dry weight) of chronic toxicity. A highly significant correlation between the concentrations of PCDD/Fs and total organic carbon (TOC) in marine sediments was observed. Overall PCDD/F concentrations in the sediments were elevated in rivers and at inner locations close to harbors, indicating that these contaminants derived from local discharges of human activities. PCDD/F concentrations measured in our study were lower than those in several industrialized areas in Korea. Nonparametric multidimensional scaling (MDS) ordination showed that combustion processes from industrial complexes are the major source of PCDD/Fs in Mokpo coastal water.

• Journal of Applied Biological Chemistry
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• v.55 no.4
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• pp.253-261
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• 2012

Dioxin contamination on agroproducts is one of the most important issue in food safety. Herein, we measured concentration of 17 dioxins polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) and 14 dioxin like-polychlorinated biphenyls (DL-PCBs) in the main grain (rice and barley) that were produced in Korea. The 36 rice samples were collected from rice processing complex at eight provinces, and the average concentrations of each province were ranged from 2.98 pg/g wet weight (w.w) to 4.98 pg/g w.w. as total PCDD/Fs and DL-PCBs. The seven barley samples were collected from Jeon-nam and Jeon-buk provinces, and their average total concentrations of PCDD/Fs and DL-PCBs were 3.00 pg/g w.w. and 3.24 pg/g w.w. respectively. The residual amounts and toxic equivalent (TEQ) of DL-PCBs in rice and barley were higher than PCDD/Fs. The average total TEQ of rice and barley were 0.0056 pg-TEQ/g and 0.0092 pg-TEQ/g on lower bound estimation respectively. Estimated daily intake of dioxins from rice and barley were calculated 1.03 pg-TEQ/day/person and 0.0534 pg-TEQ/day/person respectively. These were estimated 0.46% and 0.03% of Korean TDI based on 55 kg body weight.

• Fisheries and Aquatic Sciences
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• v.4 no.2
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• pp.51-57
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• 2001

Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) were measured in sediment samples from 19 stations in the coastal areas of Korea from February to July 2000. PCDDs and PCDFs were detected in all sediment samples. The concentrations of these con­taminants ranged from 18.2 to 804.0 pg/g dry weight and I-TEQ concentrations varied from 0.1 to 5.5 pg/g dry weight. Examination of homologue groups showed that octachlorinated dibenzo-p-dioxin (OCDD) was predominant congener in Korean coast. This pattern was similar to homologue profiles of marine sediments in which the main source of PCDDs/DFs was derived from the atmospheric deposition of particulate matters generated from various industrial activities. Grain size and total organic carbon (TOC) distribution are one of the important factors governing PCDDs/DFs concentration in this study.

• Journal of Environmental Science International
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• v.16 no.1
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• pp.9-19
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• 2007

Comparing predicted PCDF isomer patterns with those obtained from a municipal waste incinerator assessed the role of two-phenol condensation pathways in the formation of PCDFs. Complete PCDF homologue and isomer distributions were obtained from a Fluidized Bed Incinerator (FBI). Two-phenol condensation model, dependent only on the distributions of phenols, was developed to predict the PCDF congeners produced from phenol precursors. R-squared values from linear correlations are presented for the dichlorinated through hexa-chlorinated isomer distributions between measured and predicted. They range from 0.00: to 0.1 far the di-chlorinated through hexa-chlorinated isomer sets. Agreement between predicted and measured PCDF isomer distributions was very poor for all homologues. Two-phenol condensation pathways are not likely to be the pre-dominant pathways in the formation of PCDF in a FBI. However, dibenzofuran (DF) is likely to be produced from a condensation of two phenols. This work demonstrates the use of PCDF homologue and isomer patterns for testing PCDF formation mechanism from two-phenol condensation pathways in municipal waste incinerators.

• Mass Spectrometry Letters
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• v.2 no.1
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• pp.12-15
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• 2011

The Korean government has regulated emission of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in waste water of manufacturing facilities producing chlorinated compounds since 2009. As this regulation is expected to be reinforced in 2013 to 50 pg I-TEQ/L, a large sample volume is required for the analysis of trace amounts of PCDD/Fs in waste water. Liquid-liquid extraction (LLE) is used to extract PCDD/Fs from aqueous samples; however, its low efficiency makes it inadequate for analyzing large sample volumes. Herein, we present a disk-type solid-phase extraction (SPE) method for the analysis of dioxin at a part per quadrillion level in waste water. This SPE system contains airtight glass covers with a decompression pump, which enables continuous semi-automated extraction. Small (0.5 L) and large (7 L) samples were extracted using LLE and SPE methods, respectively. The method detection limits (MDLs) were 0.001.0.25 and 0.015.4.1 pg I-TEQ/L for the SPE and LLE methods, respectively. The concentrations of detected congeners with both methods were similar. However, the concentrations of several congeners that were not detected with the LLE method were quantified using the SPE method.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2001.05a
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• pp.137-137
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• 2001

It is it well known fact that the most relevant toxic emissions such as polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-1ike polychlorinated biphenyls (PCBs) are produced from incinerators. Induction of cytochrome P450IA1 catalyzed 7-ethoxyresorufin 0-deethylase (EROD) activity in mammalian cell culture (EROD-microbioassay) is a selective and sensitive parameter used for the quantification of dioxin-like compounds. (omitted)

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.10a
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• pp.9-9
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• 2003

There are growing concerns about human health effects of dioxin and dioxin like compounds such as polychlorinated dibenzo-p-dioxins (PCDDS), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs), Earlier studies recognized that 2,3,7,8-tetrachloro dibenzo-p-dioxin (TCDD) and structually related dioxin like compounds invoke a number of common toxic responses that are mediated through a high-affinity cytosolic receptor protein, the AhR. Based on studies that Indicate th pivotal role of AhR in mediating most, if not all, of the dioxin toxicity, TCDD equivalency factor (TEF) approach was developed. This approach allowed the expression of toxic potential of a complex mixture as one integrated parameter, the toxic equivalency (TEQ) value.

• Bulletin of the Korean Chemical Society
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• v.23 no.6
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• pp.817-824
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• 2002

Granular activated carbon(GAC) is highly effective in removing organic compounds which are resistant to biological disintegration in wastewater treatment. However, GAC has reached its full adsorptive capacity, GAC needs to be regenerated before it can be used for a further adsorption cycle. Countercurrent oxidative reaction (COR) technique has been developed and evaluated for the regeneration of spent GAC. Various parameters such as flame temperature, the loss of carbon, destruction and removal efficiency (DRE) of organic compounds, surface area, surface structure, adsorptive capacity, etc. were examined to determine the performance of COR. The results of these tests showed that adosorptive capacity of regenerated GAC was completely recovered, the loss of carbon was controllable, flame temperature was high enough to insure complete destruction and removal $(\geq99.9999%)$ of specific organics of interest, polychlorinated biphenyls (PCBs), that are thermally stable, and on formation of toxic byproducts such as polychlorinated dibenzo-p-dioxins (PCDDs) or polychlorinated dibenzofurans (PCDFs) were detected during the regeneration process. The COR technique is environmentally benign, easy to use and less copital intensive than other available regeneration technologies.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.207-208
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• 2001

1990년 이후 생활폐기물보다 사업장 폐기물이 많아지면서 총 폐기물 발생량은 점차 증가하고 있는 상황이다. 날로 증가하는 폐기물을 국내 실정상 매립처리하는 것은 한계가 있으므로, 효율적인 감량화 정책으로 폐기물 발생량을 저감하고, 소각에 의한 처리가 요구된다. 그러나 폐기물 소각처리는 소각 재와 유해가스를 배출하기 때문에 많은 문제점이 있다. 특히 인체에 맹독성인 다이옥신류(polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans:PCDD/Fs)가 배출되면서 현재 사회적 문제로 크게 부각되고 있기 때문에 소각시 다이옥신을 처리할 수 있는 장치의 개발이 필요하다. (중략)

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.11b
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• pp.145-145
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• 2002

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is a prototype and the most potent chemical of the polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (dioxins). A variety of studies on the toxic effects of dioxin and related compounds have been conducted internationally since 1990.(omitted)