• Journal of Environmental Science International
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• v.21 no.4
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• pp.451-459
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• 2012

PCDDs(Polychlorinated dibenzo-$p$-dioxins) and PCDFs(polychlorinated dibenzofurans) are measured in soil of Yeungju and Sangju on North Gyeongbuk to investigate the risk assessment of dioxins. Dioxins are analyzed by HRGC/HRMS(high resolution gas chromatography - high resolution mass spectrometer). 2,3,7,8-T4CDD and 1,2,3,7,8-Pe5CDD in soil on Yeungju and Sangju are not detected. Also, 2,3,7,8-T4CDF is not detected in soil on Yeungju and Sangju. PCDDs and PCDFs in Yeungju soil are 1.957 pg/g and 0.294 pg/g, respectively. Total of dioxins in Yeungju soil are 2.251 pg/g. PCDDs and PCDFs in Sangju soil are 1.220 pg/g and 0.420 pg/g, respectively. Total of dioxins in Sangju soil are 1.640 pg/g. PCDDs and PCDFs in Yeungju soil are 0.0049 pg WHO-TEQ/g and 0.0123 pg WHO-TEQ/g, respectively. Total of dioxins with PCDDs and PCDFs in Yeungju soil are 0.0172 pg WHO-TEQ/g. PCDDs and PCDFs in Sangju soil are 0.0065 pg WHO-TEQ/g and 0.0213 pg WHO-TEQ/g, respectively. Total of dioxins with PCDDs and PCDFs in Sangju soil are 0.0278 pg WHO-TEQ/g. Amount for pg/g concentration unit of PCDDs is higher than amount of PCDFs in soil. But, WHO-TEQ of PCDFs is higher than WHO-TEQ of PCDDs in soil.

• 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.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.12
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• pp.1755-1762
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• 1998

In order to minimize emission of polychlorinated dibenzo dioxins and polychlorinated dibenzo furans (PCDD/PCDFs) from municipal solid waste incinerators, it is important to maintain optimized operating conditions along with the system modification/improvement. Operating conditions of MSW incinerator make very complicated influence on formation of PCDD/PCDFs in each unit apparatus. For revealing these influences, concentrations of PCDD/PCDFs are measured from the stack and from the fly ash, while monitoring the plant operating conditions. The effects are grouped into 3 main categories, combustion conditions, de Novo synthesis effects, and adsorption/destruction effects in the flue gas treatment system. Interpretation of the results showed that de Novo synthesis effect, reformation by metalic catalyst, especially Cu in fly ash in the temperature range of $250{\sim}500^{\circ}C$, is found to influence most dominantly on the concentration of PCDD/PCDFs. A plausible mathmatical model for predicting concentration of PCDD/PCDFs is proposed, and discussed.

• Journal of Environmental Health Sciences
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• v.33 no.1 s.94
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• pp.11-15
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• 2007

This study was performed to evaluate the congeners of polychlorinated dibenzo-p-dioxins(PCDDS) and polychlorinated dibenzofurans(PCDFs) in Korean foods among children in Korea, in comparison with the findings in their mothers. The PCDDs and PCDFs intakes of 24-h diet duplicates were estimated from the previous Korean reports. In Korean children and their mothers of this study, major sources of lipid intake were plant-based foods(62% for children, 66% for their mothers). The women took 34% of lipid from animal sources, among which meats were leading sources of animal lipids(30%). Fish and shellfish were accounted for 4% in total lipid intake. Daily intake of PCDDs and PCDFs in the children md their mothers were 0.002-3.188 and 0.002-2.717 pg WHO-TEQ/day in animal sources and ND-0.283 and ND-0.296 pg WHO-TEQ/day in plant sources, respectively. PCDDs/PCDFs intake from animal origin was the major exposure source for both children and their mothers in Korea. Among the 17 PCDD/Fs congeners, 2,3,4,7,8-pentachlorodibenzofuran was assumed to be the effective exposure marker for diet intake.

• Analytical Science and Technology
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• v.17 no.4
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• pp.295-301
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• 2004

In this study, static and dynamic solvent extractions are compared for more efficient extraction of polychlorinated dibenzofurans (PCDFs) from fly ash. Static solvent extraction rather than dynamic extraction showed a higher recovery of PCDFs, which was adsorbed strongly with fly ash. The effects of parameters, such as temperature, toluene-isopropyl alcohol mixture, static and dynamic time flow rate, and solvent volume on the extraction were investigated and the variations in average recoveries of PCDFs were explained. In both extractions, temperature was an effective parameter because the higher temperature gave the higher recoveries. In dynamic solvent extraction, dynamic time was more effective than flow rate and solvent volume for the extraction of PCDFs from fly ash. Multi-layer column chromatography on neutral and acidic silica gel with n-hexane was used for cleaning up the extracts. The quantification of the PCDFs extracted was performed using HPLC-UV.

• Analytical Science and Technology
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• v.20 no.1
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• pp.10-16
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• 2007

This research was designed to investigate the formations of hazardous air pollutants in the MSWs pyrolysis-gasification-melting process. In this survey, PCDDs/PCDFs (polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofuran) were investigated in the two facilities (A and B facilities). In A facility, the PCDDs/DFs concentrations were 0.88, 2.29, 0.16 ng I-TEQ/$m^3$ respectively on the secondary incinerator, boiler and stack. In B facility, the PCDDs/PCDFs concentrations were 0.22, 0.05 ng I-TEQ/$m^3$ respectively on the pyrolysis-gasification-melting furnace and stack. The concentrations of PCDDs/PCDFs increased due to resynthesis during cooling process in the both facilities. High concentrations of PCDDs/PCDFs isomers were founded as 2, 3, 4, 7, 8-PeCDF, 2, 3, 4, 6, 7, 8-HxCDF and 1, 2, 3, 6, 7, 8-HxCDF orderly in A facility, and 2, 3, 4, 7, 8-PeCDF, 1, 2, 3, 7, 8-PeCDD and 2, 3, 4, 6, 7, 8-HxCDF orderly in B facility.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.7
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• pp.1345-1355
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• 2000

The main route of exposure of the human population to polychlorinated dibenzop-dioxins(PCDDs) and polychlorinated dibenzofurans(PCDFs) is through the diet. However in Korea, there are few studies on PCDDs/PCDFs levels in environmental samples and foods. The purpose of this study is to analyze concentration of PCDDs/PCDFs in Korean retail foods and to estimate dietary daily intake of them. 9 samples from animal food and 10 samples from plant food were analysed for PCDDs/PCDFs. Concentrations of PCDDs/PCDFs ranged from 0.02(milk) to 5.39(anchovy)pg/g. TEQ levels appeared in order of fish/shellfish, meat, vegetable, cereal, fruit and milk, and these values ranged from 0.0008 to 0.3153pgTEQ/g. The daily intake of PCDDs/PCDFs via food was calculated to be about 37.7pgTEQ/day and these values are equivalent to 0.75 pgTEQ/kg b.w./day, under consideration of 50kg for body weight. The daily intake of PCDDs/PCDFs via food was lower than that in other countries. From these results, it is important to note that fish/shellfish intake is one of the main sources of PCDDs/PCDFs exposure in Korea.

• 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.13 no.6
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• pp.789-801
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• 2000

This analysis was conducted for PCDDs/PCDFs in sediment by isotope dilution HRGC/HRMS method. From the result, the mean recovery of surrogate standard was in the range of 70.1-80.8%. Among the distribution of 2, 3, 7, 8-substituted isomers, the concentration of OCDD represented almost 40.6-78.5% of total concentration and that of OCDF showed 6.6-14.7% and 1, 2, 3, 4, 6, 7, 8-HpCDD showed 5.1-7.7%. The portion of PCDDs represented 62.4-86.9% of total PCDDs/PCDFs. In the TEQ concentration 1, 2, 3, 4, 7, 8-PeCDF concentration represented 22.7-35.6 % of total TEQ concentration.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.6
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• pp.842-850
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• 2006

The role of chlorination reactions in the formation of polychlorinated dibenzofurans (PCDFs) in a municipal waste incinerator was assessed using a chlorination model for predicting PCDF isomer distributions. Complete distributions of PCDF congeners were obtained from a stoker-type municipal waste incinerator operated under 13 test conditions. Samples were collected from the flue gas prior to the gas cleaning system. While total PCDF yields varied by a factor of five to six, the distributions of congeners were similar. A chlorination model, dependent only on the observed distribution of monochlorinated isomers, was developed to predict the distributions of poly-chlorinated isomers formed by chlorination of dibenzofuran (DF). Agreement between predicted and measured PCDF isomer distributions was high for all homologues, supporting the hypothesis that DF chlorination can play an important role in the formation of PCDF byproducts.