• Proceedings of the Korea Society of Environmental Biology Conference
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• 2005.12a
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• pp.22-35
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• 2005

내분비계 장애물질 (Endocrine Disruptors: EDs)이란 ‘내분비 기능에 변화를 일으켜, 생체 또는 그 자손의 건강에 위해한 영향을 미치는 외인성 물질’로서 세계야생생물보호기금 (World Wildife Fund: WWF)의 목록에는 67 여종, 일본 후생성에서는 142 여종의 물질을 내분비계 장애물질로 분류하고 있다. 이렇게 분류된 내분비계장애물질 가운데에는 많은 종류의 농약이 포함되어 있으며, 이들이 자연상태계에 미치는 영향에 대한 많은 보고가 있다. 양서류는 먹이연쇄의 중위포식자로 내분비계 장애물질의 순환 및 생채축적 회로에서 중요한 위치를 갖는다. 또한 농경지나 계류 등에 서식하며 산란하는 습성이 있다. 이러한 서식지는 농약 등에 노출받기 쉬우므로 환경오염평가 대상동물로 중요하다. 본 연구에서는 국내에서 사용되고 있는 제초제, 살충제 등이 양서류 발생에 미치는 영향을 평가하고, 이들 물질에 의한 노출을 평가할 수 있는 biomarker 유전자를 발굴하고자 하였다. 우리나라 전역에 많이 분포하는 무당개구리(Bombina orientalis)의 초기 배아발생 과정에서 이들 농약을 처리하였을 때, 물질의 종류에 따라 정도의 차이는 있으나 농도 의존적으로 배아 및 올챙이의 치사율이 높게 나타났다. 또한 농약은 배아 및 올챙이의 기형을 유발하였다. 기형의 종류는 농약에 따라 서로 상이한 형태로도 나타났으나, 특히 몸통휨 또는 꼬리휨등의 척추골 기형이 많이 나타났다. 환경 위해성 평가 biomarker 유전자로서 골격계 형성에 관여하는 Sox9 유전자를 선택하였다. 무당개구리에서 처음으로 Sox9 유전자를 동정하였으며, 농약을 처리한 실험군에서의 Sox9 유전자의 발현 양상은 대조군에 비하여 높게 나타났다. 본 연구결과 생태계에서 내분비계 장애물질의 위해성 평가를 위해 양서류 초기배아의 치사 및 기형의 정도를 관찰하는 방법이 유효할 것으로 사료된다. 또한 야생동물의 biomarker 유전자를 발굴과 이를 이용한 위해성 평가는 더욱 정밀한 평가법으로 유용할 것이다.

• Journal of Wetlands Research
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• v.19 no.2
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• pp.252-258
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• 2017

To determine the effects of small dam on benthic macro-invertebrate community, benthic macro-invertebrates were surveyed with both quantitative and qualitative collecting methods from 4 sites at a terraced interval (3.02 small dams per 100 m) and from 5 sites at a non-terraced interval (0.96 small dams per 100 m) in upper reach of Dorim stream, Seoul. The average water flow rate was higher at the non-terraced interval (0.149 m/s) than at the terraced interval (0.043 m/s). Diptera, which prefer slow water flow or lentic habitats, appeared more abundantly in the terraced interval (78.3%) than in the non-terraced interval (32.0%)(p<.05). Ephemeroptera, which prefer fast water flow or lotic habitats, appeared more abundantly in the non-terraced interval (14.1%) than in the terraced interval (4.5%)(p=.203). There was a difference in species distribution of Trichoptera in terraced and non-terraced intervals depending on preferred environment. In the terraced interval, the occupancy ratio of gathering-collector was 1.8 times higher than in the non-terraced interval (p<.05). In contrast, filtering-collector appeared to be about 4.4 times higher rate in the terraced interval (p=.124). The evenness indexes (J′) were found to be 0.41 and 0.77, respectively in terraced area and non-terraced intervals. KSI, evaluating biological water quality, showed an average of 4.0 and 2.4 respectively in terraced and non-terraced intervals. EPT/C index, indicating the balance of the community, showed an average of 0.1 and 0.7 respectively in terraced and non-terraced intervals. It suggests that we should make small dams in order to maintain biodiversity of benthic macro-invertebrates.

• Development and Reproduction
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• v.5 no.2
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• pp.107-114
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• 2001

The recent reports that endocrine disruptors(EDs) bring about abnormalities in reproductive organs and functions of invertebrates suggest that mammals be affected by the EDs. The present study examined the influence of 2-bromopropane(2-BP) by looking at the sexes of litters in mouse. The expression of sex-related genes during sex differentiation was also investigated in the fetus of mouse. The male and female mice were infused with 2-BP for 3 weeks before mating. The litters were sexed at the weaning time from the 4 different groups. The sex-related genes were identified by RT-PCR from the fetuses at gestation 10 days. The sequences of the genes were analysed by comparing to those of other animals. The mean numbers of litters survived by the weaning time were slightly reduced in the only group of both female and male mice treated with 2-BP. The female litters were greater than male litters in the only group of female treated with 2-BP. The other groups showed male litters greater than female litters. The sex-related genes, SRY, DAX1, SF1 , and AMH genes were identified and sequenced, showing 416, 466, 326, 389 base pairs, respectively. All of the genes had the homology of 89～90％ with rat and 81～92％ with human within the range of bases identified. They were expressed at the time of sex determination. Therefore, it appears that 2-BP somewhat affects the reproductive activity of adult mouse. Influence of 2-BP on the reproductive function is expected to be studied through the expression of the sex-related genes.

• Environmental Analysis Health and Toxicology
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• v.23 no.3
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• pp.179-186
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• 2008

내분비계 장애물질 중 에스트로겐성 특성을 지닌 것으로 알려진 bisphenol A에 폭로되었을 때에 나타나는 이상 증상과 selenoprotein N 결핍 증상은 유사성이 있는 것으로 관찰되었다. 이에 본 연구에서는 bisphenol A에 폭로된 생물체의 selenoprotein N 유전자 발현에 영향을 미치는지에 관해 연구하였다. 실험동물은 zebrafish (Danio rerio, wild type)의 수정란을 사용하였다. Zebrafish의 수정란은 서로 다른 농도의 bisphenol A (0.1, 1, 10 ppm)에 노출하였다. 각각의 폭로 환경에서 부화된 치어를 시료로 selenoprotein N 유전자 발현을 RT-PCR방법에 의해 알아보았다. 그 결과, bisphenol A는 척추이상과 심장이상이 나타나 selenoprotein N 이상시 나타나는 현상과 유사성을 보였다. Selenoprotein N 유전자 발현은 bisphenol A 폭로 농도가 높아짐에 따라 유전자 발현 농도가 낮아지는 것으로 관찰되었다. 특히 1 ppm 농도에서는 대조군이나 0.1 ppm 농도보다 catalase의 활성이 높게 나타나 특정 농도에서 bisphenol A에 의한 영향이 나타나는 것을 알 수 있었다.

• Clean Technology
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• v.18 no.1
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• pp.102-110
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• 2012

In this study, the production of bio-diesel from animal oil by esterification and trans-esterification was investigated. There were three different extraction methods for oil extraction from raw animal fat. Heterogeneous catalysts such as Amberlyst-15 and Amberlyst BD-20 and a homogeneous catalyst such as sulfuric acid were used for esterification. Among three catalysts, the removal efficiency of Free Fatty Acid (FFA) was the highest in sulfuric acid. Response surface method was carried out to find the optimal esterification condition of sulfuric acid and methanol. After the esterification under the optimal condition, this animal fat was used for the trans-esterification. Animal oil used for trans-esterification was below 1% of FFA content and 0.09% of water content. The catalysts for trans-esterification were KOH, NaOH and $NaOCH_3$. To investigate the effects of catalyst type and amount on trans-esterification, The amount of catalyst were changed with 0.3, 0.6 and 0.9 wt%. The molar ratio of methanol/oil was changed with 4, 6, 9 and 12. The amount of catalyst was fixed to 0.8 wt%. The KOH catalyst showed the highest FAME conversion for trans- esterification, and the optimal methanol/oil weight ratio was 6. In the experiments of various catalysts and methanol molar ratios, the highest content of FAME is 96%. However, this FAME content was below Korean bio-diesel standard which is 96.5% of FAME content. After distillation, FAME content increased to 98%.

• Journal of Food Hygiene and Safety
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• v.14 no.4
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• pp.408-414
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• 1999

A number of chemical released into the environment eliciting their effects by disrupting normal hormonal pathways. Endocrine disrupting compounds are present in the aquatic environment and pose potential health consequences to wildlife and humans. This review are designing fur xenobiotic estrogens based on induction of the egg-yolk precursor protein vitelloge-nin. In fish of aquatic environment, it may result in decrease fertility and egg production in females or lead to reduced gonad size or feminization of genetic male fish. It has been known that male fish exposed to estrogenic compounds show induced production of vitellogenin. Vitello-genin production is normally restricted to adult females, which have elevated estrogen levels during egg production. However, vitellogenin can be induced in males by Pollution of environmental endocrine disruptors. Consequently, the presence of vitellogenin in male fish can serve as an indicator of exposure of environmental endocrine disrupting compounds. In immature fish pol-luted at low levels of environmental endocrine disrupter, vitellogenin can serve as a reliable biomarker for exposure to endocrine disrupter. This review demonstrates the utility of vitellogenin as a biomarker fur exposure to estrogenin agents in auqatic environment.

• Korean Journal of Ecology and Environment
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• v.44 no.2
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• pp.103-112
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• 2011

Aquatic contamination by organic pollutants has been a suspected reason for rapid decrease of amphibian populations whose embryonic and larval stages are in an aquatic environment. Amphibian embryos can be a useful model to study the ecoctoxicologial impacts of aquatic pollutants. The obtained toxicological data are useful references for the management of aquatic pollutants in public health because amphibia share many developmental events with terrestrial vertebrates including humans. Safety guidelines for the toxicological effects of aquatic contaminants of chemicals identified as hazardous should be addressed at multiple endpoints. Alkylphenols have been widely-used in agricultural, industrial, and household activities; they contaminate and can persist in aquatic environments. Exposure to alkylphenols results in endocrine disruption in aquatic animals. In this review, we summarize the developmental toxicities of alkylphenols in amphibian embryos and larva according to the exposure route, chemical concentration, duration of exposure, and affected developmental stage together with mechanisms of toxicity and typical patterns of developmental abnormality. The merits of amphibian embryos as a toxicity test model for mid- to long-term exposure to aquatic pollutants are discussed proposed.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1136-1142
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• 2012

The roles of paddy fields are re-evaluated as an artificial wetland. Although 44% of total aquatic invertebrates in South Korea are observed in a rice paddy, information of their distribution and characteristics of habitat use is limited yet. This study was carried out to provide information and characterizing distribution of community of aquatic invertebrates using a rice paddy through the South Korea. Aquatic invertebrates were collected at 284 sites of a rice paddy in South Korea from June to August, 2005, 2006 and 2007. We grouped sampling sites according to its species and population of aquatic invertebrates using a non-metric multidimensional scaling (NMDS). Total 21 orders 60 families 114 species were collected from a rice paddy. Coleoptera (25%), Heteroptera (17%), Diptera (17%) and Odonata (12%) were observed. Aquatic invertebrates were classified into three groups (Group 1: Gangwon, Gyeonggi and Chungbuk; Group 2: Chungnam, Jeonbuk, Jeonnam and Jeju; Group 3: Gyeongbuk and Kyeongnam). In Group 1, Muljarus japonicas distributed mainly Gangwondo and Chungbuk. In Group 2, Sigara nigroventralis and S. substriata were mainly observed. In Group 3, higher density of Daphnia sp. and Chironomidae gen. spp. was found in the southern part of Korea.

• Korean Journal of Environmental Biology
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• v.27 no.4
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• pp.323-333
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• 2009

Parabens are alkyl esters of p-hydroxybenzoic acid, which are widely used in foods, cosmetics, and pharmaceutic products as preservatives. Absorbed parabens are metabolized fastly and excreted. Actually human body is exposed to complex mixture of parabens. Safety assessment at various toxicological end points revealed parabens have a little acute, subacute and chronic toxicities. Some reports have argued that as parabens have estrogenic activity, they are associated with the incidence of breast cancer through dermal absorption by cosmetics. There is an inference that antiandrogenic activity of parabens may give rise to a lesion of male reproductive system, but also there is an contrary. At cellular level, parabens may inhibit mitochondrial function of sperms and androgen production in testis, but also there is an contrary. Parabens seem to have little or no toxicity in embryonic development. Parabens can cause hemolysis, membrane permeability change in mitochondria and apoptosis, suggesting cellular toxicity of parabens. Parabens evoked endocrine disruption in several fish species and have toxic effect on small invertebrates and microbes. Therefore, the toxicity of parabens should be considered as a potentially toxic chemical in the freshwater environment. In conclusion, though parabens may be considered as a low toxic chemical, more definite data are required concerning the endocrine disrupting effect of parabens on human body and aquatic animals according to route and term of exposure as well as the residual concentration of parabens.

• Journal of Life Science
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• v.25 no.2
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• pp.151-157
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• 2015

Zebrafish (Danio rerio) has been more widely used to study pharmacology. Oxytectracycline (OTC) is a broad-spectrum antibiotic and works by interfering with the ability to produce essential proteins of bacteria. The aim of this study was to identify the effects of exposure to OTC on behavioral changes or endocrine response in zebrafish. The behavioral effects of exposure to OTC (50, 100 or 200 mg/l) were characterized in several novelty-based paradigms such as the novel tank or open field test in zebrafish. Moreover, to investigate effects of exposure to OTC on endocrine response, we measured whole-body cortisol level using cortisol ELISA kit. As results of novel tank test, duration in top and immobile duration were significantly increased by the exposure to OTC in a concentration-dependent manner (p<0.05). In addition, moving distance, highly mobile, velocity and zone transition were significantly decreased by the exposure to OTC in a concentration-dependent manner (p<0.05). As results of open field test, the exposure to OTC increased immobile duration significantly (p<0.05). However, moving distance, mobile duration and velocity were significantly decreased by the exposure to OTC in a concentration-dependent manner (p<0.05). Besides, the exposure to OTC elevated whole-body cortisol levels in zebrafish. These results suggest that the exposure to OTC may induce chemical stress in zebrafish.