• 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).

• 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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• 2003.05b
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• pp.249-250
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• 2003

다이옥신류의 주된 생성원인은 쓰레기 소각장에서의 배출가스에 기인한다고 알려져 있다.$^{1,3,4)}$ 그 밖에 농약제조, pulp 제조과정에서 부산물로 생성되기도 하고, 자동차배가스도 다이옥신의 생성원인 중에 하나이다. Miyabara$^{5)}$ 등은 일본내 자동차 배출가스 입자중 다이옥신류의 농도는 4.2-242 pg I-TEQ/g이였으며, 일본에서 배출하는 다이옥신류의 약 0.3%에 달한다고 추정하였다. 도로변 퇴적물 둥에서의 다이옥신 농도는 자동차 배출가스 등으로부터 직ㆍ간접으로 많은 영향을 받고 있으며, 이들이 비산할 경우 운전자의 호흡기를 통해 건강에 직접적으로 영향을 미칠 수 있다.$^{2)}$ (중략)

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1999.10a
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• pp.65-68
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• 1999

A plasma melting system to vitrify ny ash from MSW(Municipal Solid Waste) incinerator has been operated in SHI(Samsung Heavy Industries) since 1996. Waste feeding rate was 200kg/hr. with maximum working power of 500㎾. Because of high melting temperature of fly ash, bottom ash was used as an additive to decrease melting temperature. Data analysis for discharged slag shows volume reduction up to 30% and no leaching of heavy metals such as Pb, Cd, Cr which were an obstacle for landfill and recycle. Atmospheric pollution gas like nitrogen oxides, carbon monoxide, and PCDD/PCDF were restrained below the regulatory limit.

• Analytical Science and Technology
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• v.18 no.5
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• pp.419-424
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• 2005

In recent years, dioxins which were designated as persistent organic pollutants and endocrine disrupters are treated as substance of environmental pollution and studied about human health risk assessment, emission pollutants estimation, analytical methods and so on. It is easy that dioxins are accumulated to soil because of the atmosphere circulation of burning up the waste. This is the comparative studies on the distribution relationship of dioxin isomers in exhausted gas of industrial waste and urban waste incinerators, ambient air and soil. A basis of PCDDs and PCDFs based on OCDD was drawn up to the curve and they correspond to dioxin isomers in exhausted gas of industrial waste and urban waste incinerators and ambient air. On comparing these results, It was found that the ambient air and exhausted gas of industrial waste incinerators were very similar in curve and ratio. Consequently, environmental by exposed dioxin depends on the exhausted gas of industrial waste incinerators than urban waste incinerators. In case of soil, even though we can not completely rule out the possibility of pollution source bring on pesticide and other factors, and naturally biological dissociations, the curve shape is very similar to exhausted gas of industrial waste incinerators and ambient air. So, we inform here that it was mainly caused by these environmental factors.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.3
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• pp.316-322
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• 2005

In this study, the concentration of 17 dioxin congeners in the soil samples near a waste incinerator with respect to distance from incinerator and wind directions were investigated. The effect of PCB source was investigated using the cluster analysis method. The total concentration and I-TEQ concentration of dioxin ranged from 31.065 to 7,257.499 pg/g(dry weight) and from 0.099 to 35.191 pg I-TEQ/g(dry weight.), respectively. There was a weak correlation(not statistically significant) observed between soil concentration and wind direction, and the distance from the incinerator. The reason may be due to the presence of the local combustion sources other than the target incinerator. The fraction of PCDFs and PCDDs was also examined to study the effect of incinerator. The fraction of PCDFs was decreased with the distance from the incinerator. The influence of target incinerator was found within a 500-meter radius. The high concentration in the for site was due to small incinerators and the use of agricultural chemicals such as PCP. To investigate the relationship between soil near the incinerator and the sources, the cluster analysis was conducted using the congener pattern. As a result soil samples were divided into four groups and were qualitatively estimated the influence of sources such as incinerator and PCP by comparing the congener pattern of each roups. It was thought that a cluster analysis was a useful statistical method for the source estimation of dioxin.

• Analytical Science and Technology
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• v.15 no.3
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• pp.270-286
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• 2002

The human adipose and milk samples analyzed in this study were collected at hospitals in Seoul, Masan and Jinju. The mean values of International Dioxin Toxic Equivalents (I-TEQ) of PCDDs and PCDFs in human adipose samples from the three regions were calculated as 9 pg I-TEQ/g(0.2 ~ 30 pg TEQ/g, lipid weight basis) and 8 pg I-TEQ/g (0.8 ~ 25 pg TEQ/g), respectively. The residue levels of PCDDs-TEQ and PCDFs-TEQ in human milk collected from Masan were 13 pg I-TEQ/g (lipid wt.) and 4.8 pg I-TEQ/g, respectively. On the whole, the contamination levels of these compounds in the Korean population were lower than those in the other countries. Based on the analytical data and assuming a daily intake consumption of 800 mL milk with 3% fat, the average daily intake of PCDDs/DFs via human milk for a baby weighing 5 Kg could be calculated. The daily intake of PCDDs/DFs via breast-feeding was estimated to be 39 pg/kg body weight/day for 2,3,7,8-TeCDD and 86 pg/kg/day for TEQ. These levels are far above all virtually safe dose(VSD) or tolerable daily intake(TDI) values proposed by health authorities in various countries, ranging from 0.001(US EPA) to 4 pg/kag/day (WHO).

• 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.

• 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 the Korean Chemical Society
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• v.43 no.3
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• pp.286-293
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• 1999

A comnprehensive process which combines chemical with thermal treatment by controlled counterflow oxidation has been developed for disposal of PCBs in transformer oil. PCBs which not completely removed by chemical treatment, after being filtered with appropriate adsorbent during the oil circulations, was thermally treated. Destruction efficiencies of better than 99.99% was obtained, with no measurable formation of PCDDs (polychlorinated dibenzo-p-dioxins) or PCDFs (polychlorinated dibenzofurans). The combination also permits high recovery of oil and inorganic supports from scrap power transformers. The process is environmentally benign, easy to use and less capital intensive than other available technologies.