• Analytical Science and Technology
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• v.15 no.2
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• pp.142-148
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• 2002

They were analyzed that the levels of PCDDs/PCDFs in mackerel, walleye pollack, croaken and cuttlefish, which were mainly consumed in Korea, by high resolution gas chromatography/high resolution mass spectrometr (HRGC/HRMS). The samples measured in this study had been bought 3 sets of each fish from different 5 cities, Seoul, Chunchon, Daejon, Kwangju and Pusan. The TEQ level of PCDDs in mackerel (0.032 pgTEQ/g) was the highest. The TEQ level of PCDFs in walleye pollack (0.010 pgTEQ/g) was the lowest. The level of PCDDs was higher than PCDFs in fish.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.6
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• pp.599-605
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• 2005

The characteristics of PCDD/Fs were studied when accumulating on 1 to 4 year old pine needles that were used as passive samplers of atmospheric POPs. The rate of concentration increase was linear in lower(tetra- through hexa-) chlorinated PCDD/Fs, but higher (hepta- and octa-) chlorinated homologue concentrations did not increase with needle age. The lower were in gas phase and the higher in particles. Photodegradation rates of PCDDs on pine needles were similar to PCDFs, higher chlorinated PCDD/Fs tend to photolyze quickly. Therefore it is recommended that the younger needles should be collected to avoid errors from the depositional accumulation rates and photodegradation, and that, when comparing local concentrations of PCDD/Fs, needles of same age should be collected to reduce the errors.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.5
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• pp.511-521
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• 2006

Homologue and isomer patterns of polychlorinated dibenzo-p-dioxins(PCDDs) and polychlorinated dibenzofurans(PCDFs) congeners formed from phenols in the gas-phase at $600{\sim}700^{\circ}C$ and via particle-mediated reactions at $400^{\circ}C$ were studied in an isothermal flow reactor. A mixture of 20 phenols in relative concentrations found in a municipal waste incinerator(MWI) stack gas was used for this study. PCDDs and PCDFs homologue and isomer patterns obtained from the phenol. From the phenol experiments, gas-phase formation at $600{\sim}700^{\circ}C$ favors PCDFs formation whereas particle-mediated formation at $400^{\circ}C$ favors PCDDs formation. DD and DF were most abundant homologue groups, PCDDs and PCDFs homologue fraction decreased with increasing number of chlorine substituents. PCDDs and PCDFs homologue and isomer fractions were almost constant from gas-phase formation and particle-mediated formation. Unsubstituted phenol, which was present in high concentration, played a significant role in the formation of PCDD/Fs congeners under both sets of experimental conditions.

• Analytical Science and Technology
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• v.14 no.6
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• pp.504-509
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• 2001

The concentrations and TEQ levels of PCDFs/PCDDs in human aipose tissue and first breast milk were analyzed by high resolution gas chromatography/high resolution mass spectrometry. The human adipose tissue samples measured in this study have been collected at hospital in Seoul. The total concentration and TEQ level of PCDFs were showed 5.812 pg/g and 1.485 pgTEQ/g. The total concentration and TEQ level of PCDDs were showed 26.648 pg/g and 1.176 pgTEQ/g, respectively. This paper also reported dioxin levels in 20 breast milks of Korean mothers from hospital in Seoul National University. Total concentration and TEQ levels of PCDFs were showed 7.019 pg/mL and 0.177 pgTEQ/mL, respectively. Total concentrations and TEQ levels of PCDDs were showed 14.224 pg/mL and 0.693 pgTEQ/mL, respectively. According to the contribution of dioxin congeners in samples, PCDDs was higher than PCDFs. And OCDD had the highest concentration.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.4
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• pp.294-299
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• 2009

To investigate the pollution levels and behavior of PCDD/Fs in ambient air, gaseous and particulate phase concentrations were measured at Cheongju city in 2008. The samples were collected at 3 sites (industrial, residential/commercial and rural region) by season (winter, spring and summer). The concentrations and TEQ concentrations of PCDD/DFs ranged from 0.73 to 2.43 pg/$m^3$ and from 0.007 to 0.122 pg TEQ/$m^3$, respectively. These levels were similar or lower than that of other domestic researches (from n.d. to 2.149 pg TEQ/$m^3$). The concentration of PCDD/Fs in particulate phase (from 54% to 98% against total concentration) were higher than that of gas phase. As a results of comparison of congener patterns and statistical analysis, PCDD/Fs was mainly influenced by a combustion process in ambient air, Cheongju city.

• Environmental Analysis Health and Toxicology
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• v.14 no.1_2
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• pp.65-73
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• 1999

Dioxins refer to a family of chemicals comprising 75 polychlorinated dibenzo-p-dioxin (PCDD) and 135 polychlorinated dibenzo-p-furan (PCDF) congeners, which may cause skin disorder, human immune system disruption, birth defects, severe hormonal imbalance, and cancer. The effects of exposure of dioxin-like compounds such as PCBs are mediated by binding to the aryl hydrocarbon receptor (AHR), which is a ligand-activated transcription factor. To grasp physicochemical factors affecting human toxicity of dioxins, six geometrical and topological indices, eleven thermodynamic variables, and quantum mechanical descriptors including ESP (electrostatic potential) were analyzed using QSAR and semi-empirical AM1 method. Planar dioxins with high lipophilicity and large surface tension show the probability that negative electrostatic potential in the lateral oxygen may make hydrogen bonding with DNA bases to be a carcinogen.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1999.10a
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• pp.225-228
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• 1999

The formation of dioxin (term used here to refer to both polychlorinated dibenzo-p-dioxins, PCDDS, and dibenzofurans, PCBFs) in combustion processes is of concern because of the extreme toxicities of some of these compounds and because of their resistance to degradation in the environment. The number and location of chlorine substituents differentiate dioxin homologues and isomers, respectively. There are a total of 75 PCDD congeners and 135 PCDF congeners.(omitted)

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2005.05a
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• pp.298-300
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• 2005

다이옥신 29종을 분석한 결과 PCDD/PCDFs는 검출빈도가 3/4(붕어), 0/4(황소개구리)였으며, co-PCBs는 검출빈도가 4/4(붕어), 3/4(황소개구리)를 나타내었다.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.5
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• pp.346-351
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• 2009

To investigate concentration and characteristics of dioxins in soil at Cheongju city, total 28 soil samples were collected. The total and I-TEQ concentration of 17 PCDDs/DFs ranged from 2.30 to 630.40 pg/g dry weight and from 0.002 to 9.79 pg I-TEQ/g dry weight with averages of 55.42 pg/g and 1.13 pg I-TEQ/g, respectively. These levels are very lower than those of around various incinerators in Korea (from n.d. to 153.23 with average value of 7.36 I-TEQ/g). The correlation between total concentration and TEQ concentration showed significant with 99% confidence interval (p-value < 0.001). The TEQ concentration as land use was high as follows; industrial area> green area> residential and commercial area> farm land. In terms of congener distribution, OCDD which is highly detected in general soil samples, was predominant and showed various fraction (from 23 to 100%). The ratios of PCDF concentration against to PCDD concentration varied as samples (from 0.1 to 2.4).

• Analytical Science and Technology
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• v.24 no.6
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• pp.484-492
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• 2011

Bioaccumulation status and distribution characteristics of PCDDs, PCDFs and DL-PCBs in cruian carp collected from the four representative sites of major river systems in Korea were investigated. The recovery rates of PCDDs and PCDFs ranged from 50.6% to 88.3%, and those of DL-PCBs ranged from 52.3% to 93.2%. The mean, median and concentration range of ${\sum}$dioxins, which represents the total concentratons of PCDDs, PCDFs and DL-PCBs accumulated in the muscle of crucian carp, were 0.39, 0.14 and 0.047-1.0 pg TEQ/g wet wt., respectively. DL-PCBs were detected above the detection limit from all the samples, whereas PCDDs and PCDFs were detected from limited crucian samples. The relative contribution of DL-PCBs to ${\sum}$dioxins was remarkably larger than those for PCDDs and PCDFs. The percent contribution was 83.6% for DL-PCBs, and followed by 12.7% and 3.7% for PCDFs and PCDDs, respectively.