Gon Ok

Congener‐specific characterization and sources of polychlorinated dibenzo‐p‐dioxins, dibenzofurans and dioxin‐like polychlorinated biphenyls in marine sediments from industrialized bays of Korea

Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (DLPCBs) were determined in 122 coastal sediments from heavily industrialized areas in Korea. Toxic equivalent (TEQ) concentrations of PCDD and PCDF (PCDD/F) and DLPCB ranged from 0.44 to 38.5 pg/g dry weight and from 0.01 to 38.4 pg/ g dry weight, respectively. Overall PCDD/F and DLPCB concentrations were elevated in estuarine and inner bay locations close to industrial complexes, indicating that these contaminants derived from local discharges. Concentrations of PCDD/F measured in the present study were comparable to those in industrialized areas of other countries. Nonparametric multidimensional scaling ordination and congener-specific characterization showed that combustion processes occurring in industrial complexes, including the steel industry, are the major source of PCDD/Fs in Korean coastal waters. There were no significant correlations among PCDD/ Fs, DLPCBs, and total organic carbon; however, there was moderate correlation between PCDD/Fs and DLPCBs in some coastal bays, suggesting that these chemicals have similar sources and movements in these locations.

Monitoring of air pollution by polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans of pine needles in Korea.

The atmospheric contamination levels of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were evaluated from the analysis of pine needles in South Korea. Pine needles were collected from 30 sampling points at five main cities in South Korea (Busan, Daegu, Gwangju, Changwon and Jeju island). The highest concentrations of PCDDs/DFs (2.19-26.88 pg I-TEQ/g of dry weight) were measured at Busan. where is the city of the highest population density and traffic volume among five cities. The lowest concentration was detected at Jeju with 0.62 pg I-TEQ/g dry weight. suggesting Jeju could be an environmental background area in Korea. The dominant homologues of PCDDs/DFs in pine needles were the lower chlorine-substituted compounds such as tetra CDDs and CDFs, and the distribution ratios of PCDDs/DFs decreased with increase of the number of chlorine substituents. Homologue profiles of pine needle samples were similar to PCDDs/DFs profiles of the vapor phase in the ambient air, and thus the pine needles absorbed the vapor phase of PCDDs/DFs from air. Results suggested that pine needles could be used as an indicator of the atmospheric contamination for PCDDs/DFs in Korea.

Historical trends of PCDDs, PCDFs, dioxin-like PCBs and nonylphenols in dated sediment cores from a semi-enclosed bay in Korea: tracking the sources.

Two sediment cores, one at middle of the bay (core 1) and another at an outfall of a wastewater treatment plant (WWTP; core 2) were collected in Masan Bay, Korea, to investigate the historical records of contamination by polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (dl-PCBs), and nonylphenols (NPs). Vertical profiles of PCDD/Fs, dl-PCBs, and NPs in the two cores, dated using (210)Pb technique, were different but they had similar vertical profiles within the same core. The overall concentrations of these contaminants were greater in core 2 (0.05-110ng TEQkg(-1) dry wt for PCDD/Fs; 0.02-4.4ng TEQkg(-1) dry wt for dl-PCBs; 1.0-470microgkg(-1) dry wt for NPs) than in core 1 (0.72-8.0ng TEQkg(-1) dry wt for PCDD/Fs; 0.03-1.4ng TEQkg(-1) dry wt for dl-PCBs; 1.3-110microgkg(-1) dry wt for NPs). In particular, PCDD/F concentrations in core 2 were an order of magnitude greater than the concentrations in core 1. The highest concentrations of all target contaminants in cores1 and 2 were found at the surface layer (dated as 2005) and at 8-10cm ( approximately 2000), respectively. For sediment core 2, rapid changes in the concentrations and sources of target contaminants coincide with the establishment and operation of a WWTP; this suggested that discharges from WWTP contributed to contamination by PCDD/Fs, dl-PCBs and NPs in the bay. Analysis of data by non-parametric multidimensional scaling ordination showed that both the cores were influenced by different PCDD/F sources over time. Inventories and fluxes of PCDD/Fs, dl-PCBs, and NPs have rapidly increased since establishment of the WWTP, indicating that the discharge of WWTP is an important source of sediment contamination in aquatic environment.

Characteristics of PAHs, PCDD/Fs, PCBs and PBDEs in the Sediment of Lake Baikal, Russia

The levels of PAHs, PCDD/Fs, PCBs, and PBDEs in Lake Baikal were monitored for the first time using deep water sediment. The sediment samples were collected from 15 stations in four regions of Lake Baikal: Ol’khon Island (n = 8), the Angara River estuary (n = 2), the Selenga River delta (n = 2), and the Baikal pulp and paper mill (BPPM) (n = 3). The highest average concentrations of PCDD/Fs (20.24 pg/g d.w.) and PCBs (68.72 ng/g d.w.) were found at Ol’khon Island. The highest total PBDE concentrations were found at BPPM, with a mean concentration of 575.76 pg/g d.w. For PCBs, PCB-52, and PCB-69 were dominant, making up 11% of the total 209 PCB congeners. BDE-209 contributed 60% of PBDEs in Lake Baikal. According to the TPEQ concentration of PAHs, PAHs contributed the most to Lake Baikal contamination. The sources of contamination of PAHs, PCDDs, and PCBs in Lake Baikal are identified as combustion, runoff from the use of the pesticides (PCP) and insulating oil, specifically for PCBs. The source of PBDEs is assumed to be production, use and disposal of products containing PBDEs, in addition to atmospheric long-range transport and deposition.

Decomposition of chlorinated dioxins, odourous compounds and NOx from MSW incineraton plant by oxidizing catalyst

Abstract An experiment was carried out to decompose chlorinated dioxins (PCDDs, PCDFs) Chlorobenzenes, NOx and odourous compounds (H 2 S, CH 4 S, C 2 H 6 S 2 , C 8 H 8 , C 2 H 6 S, C 2 H 4 O, NH 3 ) simultaneously using a catalyst in the MSW incineration plant. The experiments were conducted at temperatures from 200°C to 400°C and from 3000h −1 to 6000h −1 at space velocity. A catalyst containing V 2 O 5 and WO 3 on the basis of TiO 2 is used, an oxidizing catalyst of the honeycomb type. The average decomposition efficiencis were 95%, 98%, 92% for PCDDs(4∼8CDDs), PCDFs(4∼8CDFs) and Chlorobenzenes(3∼6CLBs) at a reaction temperature of 350°C and a space velocity of 3000h −1 , more than 90% for NOx at a reactiont temperature of 300°C and more than 80% for odourous compounds at the reaction temperature of 300°C and a space velocity of 6000h −1 . All those compounds were decomposed successfully with increasing contact time and surface. The rate-determing step was the chemical reaction of catalyst surface.

Release of PAHs Through Runoff from the Gwangan Bridge to the Coast in Busan, Korea

This study was carried out from the Gwangan Bridge in Busan, Korea in order to examine the characteristics and the amount of PAHs in runoff from Gwangan Bridge, and the consequential PAH burdens in the ocean. The runoff samples were collected in particulate and dissolved phase, and the ambient air samples were collected in particulate and gaseous phase. In this study, 20 samples were collected from 10 different sites. The concentrations of 16 PAHs, in particulate road surface samples, ranged from 76.71 to 170.98 ng/g, and the dissolved road surface runoff samples ranged from 23.31 to 72.9 ng/L. In ambient air, the PAHs concentration in gaseous phase was higher than the samples in particulate phase. From these results, the amount of annual release of PAHs through runoff into the coast was calculated, and the Toxic Potency Equivalency Factors and Dioxin Toxic Equivalency Factors were applied. The annual release of total PAHs and the carcinogenic PAHs via runoff from Gwangan Bridge to the coast were 14.1 g/yr and 3.13 g/yr, respectively. The PAHs-TPEQ was 0.85 g/yr and the PAH-dioxin TEQ was 0.69 mg/yr.

Characteristics of Persistent of Hexachlorocyclohexane(HCH) in Ambient Air-Soil-Water-Sediment for a Emerging Persistent Organic Pollutants(POPs)

Abstract The purpose of the study was to analyze the persistence of HCH in atmosphere, soil, sediment and waterof the western and southern regions of Korea. The samples from the western region were collected from Anmyeon Island, and the samples from the southern region were collected from Kimhae and Busan. The concentration of HCH isomers in atmosphere showed the pattern of α-HCH>γ-HCH>s-HCH. The regions with high HCH concentration in the atmosphere are the regions that have been highly exposed to HCH used in the past, and the areas that have been influenced by the long range transport. The HCH that persists in the soil, water and sediment evaporates into the atmosphere, showing the characteristics of Air-Surface exchange. When the regional concentration distributions arecompared, the concentration of HCH was higher in the atmosphere of a plain and the cities near the plain, than the urban areas. In this study, the ratio of α/γ-HCH was used as an indicator for estimating the source of Technical HCH and Lindane. According to the result, the contribution of Lindane was high in Kimhae plain and Kimhae urban areas. However, in Busan, the contribution of Technical HCH was higher than Lindane. In case of Anmyeon Island, the western region of Korea had high contribution from Tehcnical HCH. In soil and sediment, s-HCH was dominant. In water, γ-HCH was dominant among other isomers. Such results are due to γ-HCH inLindane. Furthermore, the source of γ-HCH in urban areas is assumed to be the use of medicine, medical supplies and other living supplies. Based on the results of this study, the management of HCH, a newly list up emerging POPs, should be strengthened by further research on sources, fate, persistency, accumulation and exposures and etc. to the risk assessments.Key Words :HCH, POPs, Technical HCH, Lindane, α/γ-HCH ratio, Air-Surface exchange

Deposition flux of dioxin-like polychlorinated biphenyls(DLPCBs) in urban environment of Busan

Atmospheric bulk (wet and dry) samples were monthly collected in an urban environment (Daeyeon-dong) of Busan over a year, to assess the deposition flux and seasonality of dioxin-like polychlorinated biphenyls (DLPCBs) using stainless steel pots. Deposition fluxes of DLPCBs in bulk samples were determined using high resolution gas chromatography coupled to high resolution mass spectrometry (HRGC/HRMS). Particle deposition fluxes in the urban environment varied from 23 to 98 /year (mean 41 /year). DLPCB deposition fluxes in atmospheric bulk samples ranged from 0.09 to 0.77 ng-/year (mean 0.35 ng-/year). Seasonal atmospheric deposition fluxes of DLPCBs were high in winter and low in summer. Atmospheric deposition fluxes of particles and DLPCBs in this study were comparable to or slightly lower values than those of different locations in the world. Monthly DLPCB profiles in deposition bulk samples were similar over a year. Non-ortho PCBs were higher contributions to the total DLPCBs fluxes than mono-ortho PCBs. In particular, PCB 126 had the highest concentrartion (>75%) in all deposition samples, followed by PCB 169 and PCB 156. A highly positive correlation was found among the deposition fluxes of DLPCB species, suggesting the possibility of that the DLPCB contamination originated from one source. The deposition fluxes of DLPCBs were not significantly correlated with temperature and the amount of precipitation even though the summer season with the highest temperature and the largest amount of precipitation showed the lowest DLPCB deposition flux.

Estimation of polycyclic aromatic hydrocarbons emission from sewage sludge of sewerage treatment plants in Korea

Polycyclic aromatic hydrocarbons (PAHs) are an important group of organic contaminants present in sewage sludge, due to their persistence, toxic, bioaccumulative and long range transfer. These characters make themselves as Persistent Organic Pollutants(POPs) in Long Range Transboundary Air Pollutions convention(LRTAP) of Europe. A method of the gas chromatographicmass spectrometric (GCMS) determination of PAHs present in sewage sludge was developed and applied to analyzed samples from five sewerage treatment plants (SWTPs), having different treatment types. PAHs were extracted from freeze-dried samples by toluene 16 hours in a soxhlet extraction system. The sludge extracts were cleaned-up by an activated silica gel column chromatography. The sum of the 16 US Environmental Protection Agency PAHs sewage sludge samples varied from 2.44 to 4.82 /g. Concentration of emission carcinogen PAHs(PAHcarc), such as Benzo(a)anthracene, Benzo(b)f1uoranthene, Benzo(k)f1uoranthene, Benzo(a)pyrene, Dibenzo(a,h)anthracene and Indeno( 1,2,3-cd)pyrene ranged from 0.62 to 1.03 /g. The total amount of PAHs emission from sewage sludge in Korea was calculated as a top-down approach. PAHs and PAHcarc from sewage treatment plants had emitted to environment by several pathway. The highest amount of emission to the environment was remarked in the ocean dumping(PAHs and PAHcarc emissions were 1155.95 kg/year and 5040.32 kg/year, respectively).

Annual Variation and Gas/Particie Partitioning of PCDD/DFs of Ambient Air at Busan, Korea

This study aims to monitor the variation of concentration of PCDD/DFs between the gaseous phase-particulate phases in the ambient air of urban area in Korea. This monitoring is evaluated by using the Junge-Pankow model and the Koa absorption model with the application of the Octanol-air partition coefficient. In this study, the ambient air samples were analyzed according to each congener group of the PCDD/DFs by HRGC/HRMS, which have been investigated for the past 5 years. In the results, the annual variation in the concentration level of PCDD/DFs in TSP was increased from in 1998 to in 2002, and from 31 fg I-TEQ/ to 94 fg I-TEQ/ in the I-TEQ. In the case of PUF of gaseous phase sample, their variation was increased from in 1998 to in 2002, and in the I-TEQ from 12 fg I-TEQ/ to 17 fg I-TEQ/. The relative coefficient between the gas phase concentration of PCDD/DFs and the temperature was a value of 0.744; the contributive rate of the temperature to the gaseous phase concentration was 0.554. According to the results, the pattern of the coefficient of distribution based on log is similar to the ambient air of the urban areas.