• Journal of Korean Society on Water Environment
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• v.29 no.6
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• pp.842-846
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• 2013

In 2012, the Korean Ministry of Environment (MOE) added 3 new water quality standards for the protection of human health; specifically, regarding 1,4-dioxane, formaldehyde, and hexachlorobenzene. In this study, we assimilated the water quality standards of these 3 substances from other countries, with respect to surface water quality standards for human health protection and drinking water standards. We subsequently investigated how these standard values were derived. 1,4-Dioxane is managed as an environmental standard for human health in Japan, and as a drinking water quality standard in WHO, New Zealand, and Japan with respect to both carcinogenic and non-carcinogenic effects. In New York, the oncogenic effects of formaldehyde in drinking water intake is considered, whereas WHO, Australia, New Zealand, and Japan also assess the non-carcinogenic effects of formaldehyde when setting their standards. USEPA and New York have a water quality standard for human health protection with respect to hexachlorobenzene based on carcinogenic effects. This study focuses on deriving water quality standards for the 3 new substances, or obtaining baseline information to revise the values of existing substances in the future.

• The Korean Journal of Pesticide Science
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• v.4 no.4
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• pp.31-34
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• 2000

The contents of hexachlorobenzene (HCB), a hazardous impurity, in chlorothalonil were monitored through 1996 to 2000. The number of samples were 32 from three different sources. The contents determined by GLC/ECD were ranged from 0.0036% to 0.0330% with average content of 0.0219%. All the samples were recorded below 0.05%, which is the regulation standard of HCB in the technical. The total input of HCB in Korean agriculture was calculated to be approximately 77 kg a year.

• Fisheries and Aquatic Sciences
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• v.7 no.4
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• pp.215-218
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• 2004

Marine sediments and bivalves were sampled at 20 stations from coastal regions of Korea, to investigate the levels and patterns of some chlorobenzene isomers. Total chlorobenzenes were in the range of 0.32-3.55 ng/g dry weight in marine sediments and 0.26-0.84 ng/g wet weight in bivalves. Hexachlorobenzene levels in marine sediments and bivalves were lower thar or comparable to those levels of reported in other countries. Isomeric patterns of some chlorobenzenes in marine sediments and bivalves were slightly different. However, the pre-dominant isomer in marine sediments and bivalves was 1,2,4-trichlorobenzene. Hexachlorobenzene contribution to total concentrations was higher in sediments than in bivalves.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.5
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• pp.434-451
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• 2017

For this study, groundwater samples for 3 years from 2011 through 2013 were collected at 106 groundwater monitoring site in Korea. These groundwater samples were analyzed for 13 pesticides such as cabofuran, pentachlorobenzene, hexachlorobenzene, simazine, atrazine, lindane (gamma-HCH), alachlor, heptachlor, chlordane (total), endosulfan (1, 2), dieldrin, endrin, 4,4-DDT. The objectives of this study were to determine the detection frequency and their concentrations of 13 pesticides and evaluate the health risk level considering ingestion, inhalation, and skin contact using concentrations of 13 pesticides in groundwater samples. An analysis was used for the simultaneous determination for 13 pesticides using GC-MS. GC-MS was performed on HP-5ms, using helium ($1ml\;min^{-1}$) as carrier gas. The average recoveries of the pesticides were from 92.8% to 120.8%. The limits of detection (LODs) were between $0.004{\mu}g\;L^{-1}$ and $0.118{\mu}g\;L^{-1}$ and the limits of quantification (LOQs) were between $0.012{\mu}g\;L^{-1}$ and $0.354{\mu}g\;L^{-1}$. 106 groundwater wells were selected. 54 wells were from well to monitor background groundwater quality and 52 wells were from well to monitor groundwater quality in industrial or contamination source area. Eight pesticides including pentachlorobenzene, lindane (Gamma-HCH), heptachlor, chlordane (total), Endosulfan (1, 2), dieldrin, endrin, and 4,4-DDT were not detected in groundwater samples. The detection frequency for hexachlorobenzene, alachlor, carbofuran and simazine was 23.4%, 11.4%, 7.3%, and 1.0%, respectively. Atrazine was detected once in 2011. The average concentrations were $0.00423{\mu}g\;L^{-1}$ for carbofuran, $0.000243{\mu}g\;L^{-1}$ for alachlor, $0.00015{\mu}g\;L^{-1}$ for simazine, and $0.00001{\mu}g\;L^{-1}$ for hexachlorobenzene. The detection frequency of hexachlorobenzene was high, but the average concentration was low. In the contaminated groundwater, the detection frequency for hexachlorobenzene, alachlor, carbofuran, simazine and atrazine was 26.1%, 21.3%, 7.1%, 1.9% and 0.3%, respectively. In the uncontaminated groundwater, detection frequency for hexachlorobenzene, carbofuran and alachlor were 20.2%, 7.5%, and 1.9% respectively. Simazine and atrazine were not detected at uncontaminated groundwater wells. According to the purpose of groundwater use, atrazine was detected for agricultural groundwater use. Hexachlorobenzene showed high detection frequency at agricultural groundwater use area where the animal feeding area and golf course area were located. Alachlor showed more than 50% detection frequency at cropping area, pollution concern river area, and golf course area. Atrazine was detected in agricultural water use area. By land use, the maximum detection frequency of alachlor was found near an orchard. For human risk assessment, the cancer risk for the 5 pesticides was between $10^{-7}$ and $10^{-10}$, while the non-cancer risk (HQ value) was between $10^{-4}$ and $10^{-6}$. For conclusion, these monitoring study needs to continue because of the possibility of groundwater contamination based on various purpose of groundwater use.

• Journal of Electrochemical Science and Technology
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• v.12 no.3
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• pp.317-322
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• 2021

Silicon (Si) has been considered as a promising anode material because of its abundant reserves in nature, low lithium ion (Li⁺) intercalation/de-intercalation potential (below 0.5 V vs. Li/Li⁺) and high theoretical capacity of 4200 mA h/g. In this paper, we prepared a silicon-based (Si-based) anode material containing a small amount of silicon carbide by using magnesiothermic coreduction of silica and hexachlorobenzene. Because of good conductivity of silicon carbide, the cycle performance of the silicon-based anode materials containing few silicon carbide is greatly improved compared with pure silicon. The raw materials were formulated according to a silicon-carbon molar ratio of 10:0, 10:1, 10:2 and 10:3, and the obtained products were purified and tested for their electrochemical properties. After 1000 cycles, the specific capacities of the materials with silicon-carbon molar ratios of 10:0, 10:1, 10:2 and 10:3 were still up to 412.3 mA h/g, 970.3 mA h/g, 875.0 mA h/g and 788.6 mA h/g, respectively. Although most of the added carbon reacted with silicon to form silicon carbide, because of the good conductivity of silicon carbide, the cycle performance of silicon-based anode materials was significantly better than that of pure silicon.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.10a
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• pp.237-238
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• 2000

최근 산업사회의 발전에 따라 수계 오염문제가 심각하게 대두되고 있다. 따라서 이들 오염물질에 대한 모니터링을 위한 방법들이 강구되고 있으며, 이 중에서 어류 간의 cytochrome P450 호소계는 지방친화성 물질의 오염상태를 평가할 수 있는 물질로 알려지고 있다(Payne et al., 1987). PCBs(Polychlorinated biphenyls)와 HCB(Hexachlorobenzene)는 유기염소계 화합물로서 환경중에 널리 분포하고 있으며, 이중 PCBs는 신경계, 면역계 및 내분비계 등 생체내에 미치는 영향이 크므로 내분비장애물질(endocrine disruptor)로 분류되고 있고, HCB는 독성이 강한 화합물로서 주로 농업에서 fungicide로서 사용되어 왔으며. 다양한 산업 연소과정의 부산물로 발생되고 있다. (중략)

• Journal of Soil and Groundwater Environment
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• v.18 no.1
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• pp.67-77
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• 2013

To improve the energy efficiency of conventional thermal treatment, soil remediation with microwave has been studied. In this study, the remediation efficiency of contaminated soil with semi-volatile organic contaminants were evaluated with microwave oven and several additives such as water, formic acid, iron powder, sodium hydroxide (NaOH) solution, and activated carbon. For the experiment, loamy sand and sandy loam collected from Imjin river flood plain were intentionally contaminated with hexachlorobenzene and phenanthrene, respectively. The contaminated soils were treated with microwave facility and the mass removals of organic contaminants from soils were evaluated. Among additives that were added to increase the remediation efficiency, activated carbon and NaOH solution were more effective than water, iron powder, and formic acid. When 10 g of hexachlorobenzene (142.4 mg/kg-soil) or phenanthrene (2,138.8 mg/kg-soil) contaminated soil that mixed with 0.5 g iron powder, 0.5 g activated carbon and 1 ml 6.25 M NaOH solution were treated with microwave for 3 minutes, more than 95% of contaminants were removed. The degradation of hexachlorobenzene during microwave treatments with additives was confirmed by the detection of pentachlorobenzene and tetrachlorobenzene. Naphthalene and phenol were also detected as degradation products of phenanthrene during microwave treatment with additives. The results showed that adding a suitable amount of additives for microwave treatments fairly increased the efficiency of removing semi-volatile soil organic contaminants.

• Journal of Environmental Science International
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• v.14 no.2
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• pp.121-128
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• 2005

Hexachlorobenzene (HCB) was analyzed in various marine organisms of Korea. HCB was detected in all organism samples with residual concentrations from 0.51 to 222 pg/g wet weight. HCB residue was the highest content in crustacean, and followed by bivalves, fish, cephalopods and gastropods. The residues were comparable to or lower than those in marine organisms of other countries. Daily dietary intake of HCB from seafood was estimated to be 13.4 pg/kg body weight/day. The relative contribution of taxonomic group to the total dietary intake of HCB were in the order of crustaceans $(40.1\%)$, bivalves $(34.2\%)$, fish $(23.1\%)$, cephalopods $(2.22\%)$, and gastropods $(0.38\%)$. Daily dietary intake of HCB expressed as toxic equivalent (TEQ) value was estimated to be $1.34\times10^{-3}pg$ TEQ/kg body weight/day. This value did not exceed tolerable daily intake (TDI) proposed by the WHO, the UK toxicity committee and the KFDA. Cancer risk and target hazard quotient (THQ) due to the consumption of the marine organism in Korean adult population were evaluated using the exposure equation of food ingestion. This result suggests that dietary intake of HCB by the consumption of Korean seafood seems to be safe for human health with negligible cancer and non-cancer risks so far.

• Journal of Wetlands Research
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• v.9 no.1
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• pp.107-114
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• 2007

This study aimed to investigate the hexachlorobenzene (HCB) dechlorinating ability of sediment microbes collected from a natural canal receiving secondary effluents from an industrial estate and nearby factories. Nine sites along the stream and one in the estuary in the Gulf of Thailand into which the canal spills were specified and sampling for sediment and water. Preliminary analysis of the sediments showed that the first four sites nearest to the discharging location were contaminated by HCB within the range of 0.18 to 1.25 ppm. Apart from that, 1,3,5-trichlorobenzene which has never been commercially produced or used in any manufacturing processes except for the transformation from higher chlorinated benzene was also identified in the range of 0.16 to 0.24 ppm. This suggested a possibility of sporadically HCB contamination in this stream. Of more important, people in the community along this canal earn their living by coastal fishery; hence, posing a risk of spreading HCB and its less chlorinated congeners via food chain from caught marine creatures to human. As a result, there is an urgent need to understand the behavior of HCB dechlorination in this stream sediment which can lead to a clean-up action in the future. Serum bottles with sediment slurries (sediment to water ratio of 1:1 (v/v) and filtered to remove particles larger than 0.7 mm) from each site were inoculated with 2 mg/l of HCB, kept anaerobically in the dark at room temperature without any nourishment, and analyzed for HCB and its less-chlorinated congeners every 6 days. Total chemical oxygen demand, suspended solids, and volatile suspended solids were in the range of 21,492-73,584, 158,100-518,100 and 6,000-32,700 mg/l, respectively. It was found that all sediment slurries began to dechlorinate HCB in 12 to 30 days and the HCB was completely removed within 42 to 60 days or so. On the other hand, there was no HCB dechlorination occurred in the controlled set which was sterilized by autoclaving prior to the addition of HCB. This implies that the HCB transformation was solely due to microorganisms' activities. HCB was dechlorinated principally via pentachlolobenzene to 1,2,3,5-tetrachlorobenzene and terminated at 1,3,5-trichlorobenzene which is the major pathway as reported by many researchers. Dichlorobenzene has not been detected in any samples within the dechlorination period of 60 days. The results indicate that the microbial matrix in the sediment of this stream has an outstanding capability to dechlorinate HCB. Existing substrates and nutrients which mainly sorbed onto the solid phase and the typical temperature in Thailand were sufficient and suitable to promote the activities of these HCB-dechlorinating microbes.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.10a
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• pp.264-265
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• 2000

수계환경의 오염 실상을 파악하기 위해서 어류의 혈액화학적 변화는 수중의 오염물질에 의해서 그 구성이 변동되므로, 수계환경의 오염수준을 감시하는 유용한 수단으로 활용되고 있다(Khattak and Hafeez, 1996). PCBs(Polychlorinated biphenyls)는 열에 안전하고 전기 절연성이 좋은 특성을 가지고 있어 1929년부터 미국의 Monsanto사에서 Arochlor란 이름으로 시판되어 상업적으로 이용되기 시작하였다(Hutzinger. et al., 1986). (중략)