• 한국환경과학회지
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• 제20권11호
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• pp.1383-1394
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• 2011

Environmental impacts of suspended solids (SS) released in coastal area by dredging, reclamation and construction can cause serious damages to coastal habitats and benthic organisms. Acute toxicity tests (4-7 days) were conducted to identify the relationship between SS concentration and mortality of three marine benthic species; benthic copepod (Tigriopus japonicus) adult, Pacific abalone (Haliotis discus hannai) spat, and olive flounder (Paralichthys olivaceus) fry. Benthic copepod was the most sensitive to SS followed by olive flounder fry and Pacific abalone spat, with an $LC_{50}$ (lethal concentration of 50% mortality) value of 61.0 mg/L and LOEC (lowest observed effective concentration) value of 31.3 mg/L for benthic copepod. LOEC and 7 day-$LC_{50}$ for Pacific abalone spat were 500.0 mg/L and 1887.7 mg/L, and those for olive flounder fry were 125.0 mg/L and 156.9 mg/L, respectively. The tolerance limits of the test species to SS revealed the various concentration ranges of SS, which reflects the physiology and ecology of the test species. These results are very valuable for the determination of SS concentration of effluents released into the coastal area by dredging, reclamation and construction etc. Also, sharp increase of SS can cause long-term damages to the benthic and sessile fauna by blanketing of benthic substratum. These experimental procedures for marine bioassay and acute toxicity results can be a useful guideline for practical management planning of SS discharge into coastal area.

• 한국환경생태학회지
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• 제26권5호
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• pp.675-681
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• 2012

국내에 서식하는 개구리의 배아를 이용하여 화학물질의 독성평가에 대한 가능성을 파악하기 위해 FETAX(Frog Embryo Teratogenesis Assay-Xenopus) 기법에 따라 청개구리(Hyla japonica)의 배아를 배양하면서 $Cu^{2+}$과 Tebuconazole의 효과를 probit 분석법으로 조사하였다. 그 결과, $Cu^{2+}$과 Tebuconazole의 농도에 의존하여 유생의 체장 길이는 감소하고 치사율과 기형율은 증가하였으며 $Cu^{2+}$과 Tebuconazole의 teratogenic concentration($EC_{50}$)은 각각 0.05, 5.0mg/L을 나타내었고 embryo lethal concentrations($LC_{50}$)은 0.16, 39.1mg/L을 나타내었다. Teratogenic index($TI=LC_{50}/EC_{50}$)는 $Cu^{2+}$의 경우 3.0, Tebuconazole의 경우 7.7을 나타내어 청개구리 배아 발달에 최기형성 물질로 작용함을 알 수 있었다. 이상의 결과들로 보아 $Cu^{2+}$과 Tebuconazole 모두 낮은 농도에서 청개구리 배아의 발달에 민감하게 반응하였으며 다량의 배아 확보가 가능하였고 배양이 용이하였으며 치사율, 기형율, 성장률, 기형양상 등이 기존의 연구들과 비교하였을 때 유사한 결과를 나타내어 청개구리 배아를 활용한 시험기법은 화학물질 및 환경오염물질의 독성검정에 활용할 수 있을 것으로 판단된다.

• 한국수산과학회지
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• 제46권6호
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• pp.923-929
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• 2013

Black seabream juveniles Acanthopagrus schlegelii held at $20^{\circ}C$ were exposed to formalin at concentrations of 50 to 400 ppm, and tolerance values were determined by calculating median lethal concentration values (LC50) through probit analysis. The 12-, 24, 48, 72- and 96-h LC50 values for formalin were 297, 233, 171, 162 and 157 ppm, respectively. The histological effects of formalin on gill and liver tissues in this fish were determined. No histological effects were observed in the control group. The intensity of cell damage increased with the concentration of, and duration of exposure to, formalin. Hyperplasia, separation and epithelial necrosis, epithelial lifting, lamellar synechiae and collapsed lamellae were observed in gill tissues exposed to formalin. Hepatic lesions in liver tissues of fishes exposed to formalin were characterized by cloudy swelling of hepatocytes, necrosis, cytoplasmic vacuolization, deposition of pigments, spongiosis hepatis, nuclear hypertrophy, dilation of sinusoids and bile stagnation. The LC50 values and histological results obtained in this study will aid in designing treatment regimens to minimize toxic side effects and increase efficacy.

• 한국양식학회지
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• 제11권2호
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• pp.223-230
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• 1998

This study was carried out for the purpose of developing environmental friendly and effective chemical treatment method for the disease control in the land-based flounder culture which is industrially popular in the coastal area in Korean. The chemicals such as flounder, Paralichthys olivaceus and their effects on the fish based on the 24hr-$LC_{50}$, $LT_{50}$, 24-hour survival rate at each experimental concentration, recovery rate of the survived individual from chemical treatment, and the histological change of the gill after chemical treatment were investigated and analyzed. The 24hr-$LC_{50}$ was 321.65 ppm for formalin, 419.62 ppm for chlorine dioxide, and 395.97 ppm for hydrogen peroxide, respectively. The $LT_{50}$ was 15-hour for formalin, 17-hour for chlorine dioxide and 24-hour for hydrogen peroxide, respectively. Fishes exposed to the experimental concentration of three chemicals were quickly susceptible in the order of formalin, chlorine dioxide and hydrogen peroxide with a trend of shorter half lethal time at higher concentration. Initial survival rate of the flounder soon after chemical treatment was the highest in the hydrogen peroxide treatment compared with the other two chemicals. The histological damage by the hydrogen peroxide treatment was negligible compared with the other two chemicals. Accordingly, hydrogen peroxide treatment showed the lowest toxicity compared with the other two chemicals to the experimental fishes.

• 환경생물
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• 제28권2호
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• pp.64-68
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• 2010

본 실험은 구리가 흰줄숲모기, Aedes albopictus의 발생에 미치는 생물학적 영향을 조사하기 위하여 수행하였다. 흰줄숲모기 3령, 4령 유충을 각각 다른 농도의 구리 용액(0.0, 2.5, 25.0, 50.0 ppm)에서 24시간, 48시간 처리한 후 치사농도를 결정하고, 사육용액(tap water)으로 옮겨 사육하여, 유충의 용화율, 성충의 날개길이를 측정한 결과는 다음과 같다. 50% 치사농도($LC_{50}$)는 4령 유충 24시간 처리군에서 35.65 ppm으로 나타나 다른 처리군에 비해 가장 저항성을 지닌 것으로 나타났다(Table 1). 유충의 용화율은 고농도 48시간 처리군에서 낮게 나타났으며 특히 3령 유충 48시간 처리 군에서 14% (암컷 9%, 수컷 5%)로 가장 낮았다. 또한 우화 후 성충의 날개 길이는 처리 농도가 증가하고 긴 처리 시간이(48시간) 감소하는 것으로 나타났다. 이러한 실험 결과들은 흰줄 숲모기의 각 발생단계에 구리를 처리한 결과 처리 농도 및 처리 시간에 따라 치사량, 용화율, 날개길이 등에 많은 변화를 나타내었는데 이는 중금속이 곤충의 유충발육과 변태에 영향을 끼치며, 이와 수반되는 물질대사에 도 영향을 미치는 것으로 여겨진다.

• Journal of Microbiology
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• 제44권1호
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• pp.77-82
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• 2006

The tea looper caterpillar, Ectropis obliqua, is one of the major pests of tea bushes. E. obliqua single-nucleocapsid nucleopolyhedrovirus (EcobSNPV) has been used as a commercial pesticide for biocontrol of this insect. However only limited genetic analysis for this important virus has been done up to now. EcobSNPV was characterized in this study. Electron microscopy analysis of the occlusion body showed polyhedra of 0.7 to $1.7\;{\mu}m$ in diameter containing a single nucleocapsid per envelope of the virion. A 15.5 kb genomic fragment containing EcoRI-L, EcoRI-N and HindIII-F fragments, was sequenced. Analysis of the sequence revealed that the fragment contained eleven potential open reading frames (ORFs): lef-1, egt, 38.7k, rrl, polyhedrin, orfl629, pk-1, hoar and homologues to Spodoptera exigua multicapsid NPV (SeMNPV) ORFs 15, 28, and 29. Gene arrangement and phylogeny analysis suggest that EcobSNPV is closely related to the previously described Group II NPV. Bioassays on lethal concentration $(LC_{50}\;and\;LC_{90})$ and lethal time $(LT_{50}\;and\;LT({90})$ were conducted to test the susceptibility of E. obliqua larvae to the virus.

• Journal of Veterinary Science
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• 제25권1호
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• pp.5.1-5.10
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• 2024

Background: External parasites, particularly ticks and fleas, are among the most common problems affecting dogs. Chemical medicines are commonly used to prevent and eliminate such external parasites, but their improper use can cause adverse reactions, and the toxins they contain may remain in the environment. Objectives: The objective of this study was to investigate the in vitro efficacy of Zanthoxylum limonella, citronella, clove, peppermint, and ginger essential oils against dog ticks and fleas and to test the sensitivity of dogs' skin to these essential oils. Methods: The five essential oils were tested for in vitro efficacy against ticks and fleas, and the two most effective essential oils were then tested on the dogs' skin. Results: The results revealed that these five essential oils at 16% concentrations effectively inhibited the spawning of female engorged ticks. In addition, all five essential oils had a strong ability to kill tick larvae at concentrations of 2% upward. Furthermore, 4% concentrations of the five essential oils quickly eliminated fleas, especially clove oil, which killed 100% of fleas within 1 h. A 50%, 90%, and 99% lethal concentration (LC₅₀, LC₉₀, and LC₉₉) for the essential oils on tick larvae in 24 h were found to be low values. LC₅₀, LC₉₀, and LC₉₉ for the essential oils on flea in 1 h was lowest values. Clove oil at 16% concentration was the most satisfactory essential oil for application on dogs' skin, with a low percentage of adverse effects. Conclusions: This study confirmed the effectiveness of essential oils for practical use as tick and flea repellents and eliminators. Essential-oil-based pharmaceutical can replace chemical pesticides and provide benefits for both consumers and the environment.

• 한국해양생명과학회지
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• 제7권2호
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• pp.129-138
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• 2022

붕어(무게 42.4±9.0 g, 길이 15.0±1.0 cm)를 96시간 동안 0, 5, 10, 20, 40 및 80 mg Zn²⁺/l의 수인성 아연에 노출시켰다. 수인성 아연에 노출된 붕어의 96시간 반수치사농도(LC₅₀)는 51.58 mg Zn²⁺/l였다. 혈액학적 지표에서 48시간에 40 mg Zn²⁺/l 농도에서 RBC 수치가 유의하게 감소한 반면, 헤마토크릿은 아연 노출에 의해 유의하게 증가하였다. MCV (µl)와 MCH (pg)는 40 mg Zn²⁺/l 농도에서 48시간에 유의하게 증가하였다. 칼슘, 마그네슘, 포도당, 콜레스테롤, 총 단백질 및 ALT와 같은 혈장 성분은 아연 노출에 의해 크게 변화되었다. 본 연구의 결과는 붕어에 대한 아연 노출이 독성으로서 혈액학적 매개변수 및 혈장 성분의 유의한 생리학적 변화를 유발함을 시사한다.

• 한국수산과학회지
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• 제27권5호
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• pp.529-534
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• 1994

해역에 오염을 일으킬 것으로 예상되는 Micropollutants로서 크롬, 구리, 아연, 수은, 카드뮴 및 LAS를 택하여 서해안의 대표적인 유용 어종인 조피볼락, 넙치 및 숭어에 대한 급성독성실험을 행한 결과 다음과 같은 결론을 얻었다. 1. 각종 중금속이나 LAS에 대한 넙치, 숭어, 조피볼락의 내성은 일정한 경향이 없었으나 기수성 어류인 숭어가 대체로 약하였고 독성물질 중 수은과 LAS의 독성이 특히 강하였다. 2. 크롬의 어종별 96hr-LC50은 8.4mg/l, 숭어1.14mg/l, 조피볼락 26.65mg/l으로 조피볼락이 타어종에 비해 내성이 훨씬 강하였다. 3. 구리의 어종별 96hr-LC50은 넙치 16.1mg/l, 숭어 2.32mg/l, 조피볼락 0.18mg/l으로 조피볼락의 내성이 타어종에 비해 매우 낮았으며 특히 조피볼락의 MATC는 $0.053{\sim}0.0053mg/l$으로 서해 연안역의 $92{\sim}93$년도 농도가 $0.003{\sim}0.012mg/l$인 점으로 보아 구리 오염에 주의할 필요가 있음을 알 수 있었다. 4. 아연의 어종별 96hr-LC50은 넙치 5.2mg/l, 숭어 13.75mg/l, 조피볼락 6.95mg/l으로 나타났다. 5. 수은의 어종별 96hr-LC50은 넙치 0.28mg/l, 숭어 0.1mg/l, 조피볼락 0.01mg/l으로 조피볼락이 타어종에 비해 내성 낮았으며, 특히 조피볼락의 MATC는 $0.0007{\sim}0.007mg/l$으로 $92{\sim}93$년도의 서해 연안역의 수은 농도가 $0.001{\sim}0.005mg/l$인 점을 고려하여 볼 때 수은 오염에 주의할 필요가 있음을 알 수 있었다. 6. 카드뮴의 어종별 96hr-LC50은 넙치 28.4mg/l, 숭어 2.55mg/l, 조피볼락 28.7mg/l으로 나타났다. 7. LAS의 96hr-LC50은 0.79mg/l이었고, 숭어에 대한 96hr-LC50은 0.06mg/l, 조피볼락 1.08mg/l으로 기수성 어류인 숭어의 내성이 매우 낮은 점이 특이하였다.

• 한국안전학회지
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• 제21권6호
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• pp.38-45
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• 2006

Polymeric floorings mainly consisted of PVC are easily decomposed by many kinds of hot environmental factors, then generate hazardous asphyxiate gases and/or toxic gases etc. Therefore the mechanism of decomposition and quantitative toxic indices of products are very important for preventing safety and health disasters, especially in case of confined area. So we have investigated decomposition kinetics, numbers of process involved, toxicity indices of product and so on, using DSC, TGA, FT-IR and Pyrolyzer-GC/MS. The thermal decomposition process of polymeric floorings can be mainly divided by dehydrochlorinated reaction and polyene decomposition step, and activation energies of those are approximately $53.93{\sim}62.42kcal/mol$. Especially lethal concentration($LC_{50}$), fractional effective dose (FED) are calculated by measuring the amount of decomposition product. The values on $LC_{50}$ of sample G are ranged $2,003{\sim}2,019(mg/m^{3})$ in case of sample K and H are $1,877,\;1,998(g/m^{3})$ respectively. Even if the results are estimated by calculation method without animal test and/or clinical demonstration, these values could be very useful data for occupational health, hygiene and safety control.