• Journal of Environmental Science International
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• v.19 no.12
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• pp.1343-1354
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• 2010

The purpose of the study was to analyze the persistence of HCH in atmosphere, soil, sediment and water of 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 $\alpha$-HCH>$\gamma$-HCH>$\beta$-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 are compared, 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 $\alpha/\beta$-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, $\beta$-HCH was dominant. In water, $\gamma$-HCH was dominant among other isomers. Such results are due to $\gamma$-HCH inLindane. Furthermore, the source of $\gamma$-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.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.3
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• pp.183-192
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• 2002

Concentrations of $\alpha$- and ${\gamma}$-hexachlorocyclohexane (HCH) were measured in ambient air samples at a two week intervals between July 1999 and February 2000 at Ansung, Kyonggi province. Their concentration levels averaged at 78 ($\alpha$-HCH) and 18 pg/m$^3$(${\gamma}$-HCH). Although the use of HCHs was ceased in South Korea since 1979, their residues are still present in air even after nearly 20 years. Given the composition of the two main HCH pesticide formulation (technical HCH antral lindane), the $\alpha$/${\gamma}$-HCH ratio in air is a useful indicator on the regional scale. The moderately low $\alpha$/${\gamma}$-HCH ration in this study indicates previous usage of both technical HCH and lindane. The relationship of temperature with gas-phase partial pressures was also examined using the Clausius-Clapeyron equation. Slopes generated by linear regression analysis between partial pressure (In P) and 1/T were considerably steep thor HCHs. It is thus suggested that their concentrations are controlled by re-volatilization processes from surfaces in the local surroundings of the sampling site.

• The Transactions of the Korea Information Processing Society
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• v.1 no.1
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• pp.105-113
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• 1994

This paper introduces the Parallel Advanced Loosely coupled Multiprocessor (PALM) architecture, which is based on HCH(m,p), where m is number of links per a communication processor (CP) and p is the number of application processors (APs) connected to the CP. communication links between a pair of CPs and/or between a CP and an AP, are made of dual-Port RAMs, which provide fast and reliable word-parallel communication between processors. Among the wide spectrum of HCH networks, HCH(m,2) is also known to be a cost optimal topology, such that HCH(m,2) consists of the largest number of APs retaining the minimal number of CPs and communication links. We also implement a testbed based on HCH(2,2). The experiment result shows that the small communication/computation ratio of the PALM system would realize fine-grain parallelism on message-passing MIMD systems.

• Journal of Microbiology and Biotechnology
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• v.21 no.8
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• pp.858-860
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• 2011

Production of biosurfactant can be substantially increased by the addition of precursors like vegetable oils, petroleum products, and other water-insoluble substances. Pseudomonas Ptm+ strain produces biosurfactant in the presence of hexachlorocyclohexane (HCH), which specifically emulsifies HCH, a recalcitrant organochlorine pesticide. Addition of previously produced crude biosurfactant by the same organism as a precursor instead of HCH increased production of biosurfactants with a decrease in the total fermentation time from 32 to 24 h. The main objective of this paper was to find alternatives for HCH as an inducer.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.157-158
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• 2001

Hexachlorocyclohexane(HCH, 또한 benzene hexachioride(BHC)라고도 부름)은 세계 도처에서 발견되는 주요 난분해성 유기염소계 화합물들(persistent organochlorine compounds)중 하나이며, 또한 환경중 거동 및 영향들과 관련하여 가장 많이 연구되어진 살충제중 하나이다(Li et al., 1996). Technical HCH mixture($\alpha$-, $\beta$-, ${\gamma}$-, $\delta$- 및 $\varepsilon$-HCH 이성질체들의 혼합물)와 technical lindane(거의 단일의 ${\gamma}$-HCH 이성질체로 구성)은 농업, 산림 및 위생 방면에 다양한 목적을 위해 1940년말 이래로 많은 양이 사용되어져 왔다(Li et al., 1996; Breivik et al., 1999). (중략)

• Analytical Science and Technology
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• v.23 no.2
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• pp.128-137
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• 2010

The purpose of this study is to set up the analytical method of new persistent organic pollutants (POPs) such as chlordecone, endosulfan, ${\alpha}$-HCH, ${\beta}$-HCH, ${\gamma}$-HCH. The analytical methods for these compounds listed as new POPs by the Stockholm Convention need to be newly established. Therefore, we proposed the analytical method for 5 organic chlorinated pesticides (OCPs) and then applied the analytical method to environmental samples. To do this, the pre-treatment such as florisil and activated carbon cleanup process in the Korean official method for classic POPs had been reviewed. All of compounds except chlordecone were pre-treated simultaneously with reviewed cleanup process and detected by GC/MS and HRGC/HRMS respectively. There is a problem that chlordecone could not get a high sensitivity by GC analysis, but in this study GC/MS method was proposed.

• The Korean Journal of Pesticide Science
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• v.15 no.4
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• pp.502-506
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• 2011

Most countries have the legislation and regulation for POPs control in food. In here, we studied the quantitative analysis of 24 organochlorine POPs (${\alpha}$-HCH 1, ${\beta}$-HCH 2, ${\gamma}$-HCH 3, ${\delta}$-HCH 4, trans-chlrodane 5, 2,4'-DDE 6, ${\alpha}$-endosulfan 7, cis-chlordane 8, 2,4'-DDD 9, endrin 10, ${\beta}$-endosulfan 11, 2,4'-DDT 12, endosulfan sulfate 13, HCB 14, aldrin 15, trans-nonachlor 16, 4,4'-DDE 17, dieldrin 18, 4,4'-DDD 19, cis-nonachlor 20, 4,4'-DDT 21, heptachlor 22, heptachlor epoxide 23 and mirex 24) with GC-ECD. The retention time of analytes were ranged between 19.18 min and 34.69 min, and their peak intervals were over 0.05 min at least. LOQs were ranged 0.003 ~ 0.033 ng/g, and their recovery rates were showed 60.9 ~ 120.8% on the 0.1 ng/g concentration of 24 organochlorine POPs. All tested 30 sundried salts were collected on Korean retailed market, and any analyte was not found in all the samples on LOQ levels.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.2
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• pp.221-226
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• 1985

This investigation was undertaken to clarify the effects of consecutive application of insecticide (Hexachlorocyclohexane: HCH, 10 ppm each year) and fungicide (Tetrachloroisophthalonitrile: TPN, 40 ppm each year) on changes of the composition of soil bacterial flora in the experimental plots treated with each pesticide for two years. For these purposes, the isolating of bacterial cells growing on albumin agar plate was carried out with non-treated, HCH-treated and TPN-treated soil. And these isolated strains were grouping in accordance with the first diagnostic table of Cowan & Steel based on the morphological and physiological characteristics of bacterial cells. The mortality rate of bacteria was 30% in control, 44% in HCH and 51% in TPN plot respectively, in the process of obtaining pure culture. This suggests that the application of HCH or TPN enriched the fastidious bacteria in soil. The proportion of Gram-negative strains to the total isolates was 37% in control, 37% in HCH and 75% in TPN plot respectively. This means that the application of TPN enriched Gram-negative strains in soil. And the application of TPN increased the number of Gram-negative, nonspore-forming strains, and meanwhile decreased the number of spore-forming strains. In the results, the application of HCH or TPN changed considerably the composition of soil bacterial flora. And the influences of HCH and TPH on changes of the composition of soil bacterial flora were not equal each to each.

• Molecules and Cells
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• v.40 no.12
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• pp.976-985
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• 2017

Iron is an essential divalent ion for aerobic life. Life has evolved to maintain iron homeostasis for normal cellular and physiological functions and therefore imbalances in iron levels exert a wide range of consequences. Responses to iron dysregulation in blood development, however, remain elusive. Here, we found that iron homeostasis is critical for differentiation of Drosophila blood cells in the larval hematopoietic organ, called the lymph gland. Supplementation of an iron chelator, bathophenanthroline disulfate (BPS) results in an excessive differentiation of the crystal cell in the lymph gland. This phenotype is recapitulated by loss of Fer1HCH in the intestine, indicating that reduced levels of systemic iron enhances crystal cell differentiation. Detailed analysis of Fer1HCH-tagged-GFP revealed that Fer1HCH is also expressed in the hematopoietic systems. Lastly, blocking Fer1HCH expression in the mature blood cells showed marked increase in the blood differentiation of both crystal cells and plasmatocytes. Thus, our work suggests a relevance of systemic and local iron homeostasis in blood differentiation, prompting further investigation of molecular mechanisms underlying iron regulation and cell fate determination in the hematopoietic system.

• Environmental Analysis Health and Toxicology
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• v.22 no.2 s.57
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• pp.177-184
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• 2007

Gaseous organochlorine pesticides (OCPs : heptachlor epoxide, p, p'-DDE, ${\gamma}-HCH,\;{\alpha}-chlordane,\;{\gamma}-chlordane$ and trans-nonachlor) concentration was measured using PUF high volume sampler from June, 2000 to June, 2002 in the semi-rural atmosphere. The OCPs concentration in atmosphere, which is estimated by the slope (m) of Clausius-Clapeyron equation and phase-transition energy $({\Delta}H)$, was influenced by revolatilization from environmental matrix (soil, water and tree leaves) and a long range transportation of air mass. But the former affected OCPs concentration more than the latter. The degradation rate constants (k) of OCPs calculated using multiple regression analysis and revised standard temperature method were in good agreement each other. The value of k of ${\gamma}-HCH$ was very low as -0.0007, but the range of k of other components were $-0.00l8{\sim}-0.0038$. The half-life $({\tau})$ which was calculated by k of ${\gamma}-HCH$ was 2.6 years-the longest one, but that of heptachlor epoxide was in 0.5 year-the shortest one. $({\tau})\;of\;{\alpha}-chlordane,\;{\gamma}-chlordane$ and trans-nonachlor in technical chlordane was 1.0, 1.1 and 0.7 year respectively.