• Title/Summary/Keyword: Lethal concentration

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Antimicrobial Activity of Quercus mongolica Leaf Ethanol Extract and Organic Acids against Food-borne microorganisms (식중독균에 대한 신갈나무 잎 추출물과 유기산의 항균효과)

  • Kong, Young-Jun;Park, Boo-Kil;Oh, Deog-Hwan
    • Korean Journal of Food Science and Technology
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    • v.33 no.2
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    • pp.178-183
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    • 2001
  • This study was conducted to determine the optimal extraction condition of temperatures and kinds of extraction solvent, and antimicrobial activity of ethanol extract of Quercus mongolica leaf and organic acid against foodborne microorganisms. The antimicrobial activity of ethanol extract at $60^{\circ}C$ for 6 hour against foodborne microorganisms was stronger than those at $30^{\circ}C\;and\;90^{\circ}C$. Also, the ethanol extract showed stronger antimicrobial activity than those of water and methanol extract. The minimal inhibitory concentrations of the ethanol extract of Quercus mongolica leaf against B. cereus and L. monocytogenes, was $62.5{\sim}125\;{\mu}g/mL$ but, the minimal inhibitory concentration was $250\;{\mu}g/mL$ against S. typhimurium and P. aeruginosa and over $500\;{\mu}g/mL$ against E. coli O157:H7, respectively. The minimal inhibitory concentrations of the lactic, citric, acetic acid and the ethanol extract of Quercus mongolica leaf against B. cereus and L. monocytogenes was 2500, 5000, 1250 and $125\;{\mu}g/mL$, respectively. The combined effect of each organic acid and the ethanol extract against B. cereus was not observed but, synergistic effect was observed against L. monocytogenes. In the meantime, when the ethanol extract was combined with each organic acid at sub-lethal concentration, the combination did not increase the inhibitory effect of the most active single compound alone against E. coli O157:H7, respectively.

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Effects of Heavy Metals on Mortality and Metabolite Changes in Mosquitoes, Culex pipiens pallens (Diptera: Culicidae) (중금속이 빨간집모기(Culex pipiens)의 치사율과 대사물질의 변화에 미치는 영향)

  • Lee, Su Mi;Shin, Byung Sik
    • Korean Journal of Environmental Biology
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    • v.36 no.4
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    • pp.694-700
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    • 2018
  • To investigate the effect of heavy metals (Cu, Cd, Hg, Pb, Zn) on mosquito Culex pipiens, 50% lethal concentration ($LC_{50}$) concentration, total lipid content, lipid content composition, and total protein content were measured. The results showed that the Hg $LC_{50}$ was $0.45mg\;kg^{-1}$ and the Hg toxicity was higher than the other metals. The results also showed that cadmium (Cd) significantly retarded the growth of mosquito larvae among the tested heavy metals. Six types of lipid bands were isolated from mosquito samples exposed to heavy metals, and five of them were identified (phospholipid, cholesterol, fatty acid, triglyceride, and cholesterol ester). The total lipid content of all treatments decreased compared to the control. In addition, the protein content of the control group ($0.51mg\;ind.^{-1}$) was higher than that of the treated group, and the protein content of the larvae treated with Hg and Cd was very low. In conclusion, heavy metals not only lower the survival rate of mosquitoes, but also affect the protein content and lipids in the mosquito's body, thereby causing growth inhibition. These results indicate that heavy metal contamination will affect the size of mosquito population by inhibiting the survival and growth of mosquitoes, and it is expected that it can be used to measure the degree of contamination using mosquito through subsequent studies.

Bio Toxicity Assessment and Kinetic Model of 6 Heavy Metals Using Luminous Bacteria (발광미생물을 이용한 중금속 6종의 생물독성 평가 및 모델링)

  • Kim, Ilho;Lee, Jaiyeop
    • Journal of the Korean Society of Urban Environment
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    • v.18 no.4
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    • pp.547-555
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    • 2018
  • In addition to North America and Europe, Korea is also responding to the toxic damage caused by the production and distribution of chemicals. Methods for assessing bio-toxicity of harmful substances have been widely introduced, but it is required of quantitative and speedy information for modeling. For 6 heavy metals, as zinc, copper, chrome, cadmium, mercury and lead, bio-toxicity assessment and kinetics model were constructed using Vibrio fischeri which is widely used luminous bacteria. The degree of luminescence activity and the toxicity of heavy metals were relative limunescence unit, RLU measured as by using a photomultiplier embedded device. The toxicity was assessed by the concentration levels giving under 20% lethality and lethal concentration, $EC_{50}$. In the results, the toxicity order were followed from mercury, lead, copper, chrome, zinc and cadmium. $EC_{{50},{\infty}}$ obtained by trends of $EC_{50}$ by time follows had highly linear agreement with main parameters of bio-toxicity modelling. The average error rates of the reproduced lethality obtained from DAM and TDM model on the basis of body residue, were 10.2% for mercury, lead, copper, chrome and 20.0 for the all 6 methals.

Toxic Effects on Lethal Concentration 50%, Heamatological Parameters and Plasma Components of Crucian carp, Carassius carassius by Acute Waterborne Nickel Exposure (수인성 니켈 급성 노출이 붕어, Carassius carassius의 반수치사농도, 혈액학적 성상 및 혈장 성분에 미치는 독성 영향)

  • Chang-Hoon, Joo;A-Hyun, Jo;Su-Min, Hong;Ji-Ho, Jeong;Yun-A, Ryu;Seock-Won, Jo;Jae-Hee, Song;Jun-Hwan, Kim
    • Journal of Marine Life Science
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    • v.7 no.2
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    • pp.102-112
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    • 2022
  • Crucian carp, Carassius carassius (Weight 39.7±3.1 g, Length 14.8±0.5 cm) were exposed to waterborne nickel at 0, 10, 20, 40, 80 and 160 mg Ni2+/l. The lethal concentration 50 (LC50) of C. carassius exposed to waterborne nickel was 117.69 mg Ni2+/l. In hematological parameters, RBC counts was significantly increased at 48 hours, whereas a significant decrease was observed at 96 hours. The MCV and MCH were significantly increased in the concentration of 80 mg Ni2+/l at 96 hours. The plasma components such as calcium, magnesium, glucose, cholesterol, total protein, AST, ALT and ALP were significantly changed by waterbonre nickel exposure. The results of this study suggest that the nickel exposure to C. carassius affects the survival rates, hematological parameters and plasma components as toxicity

Compound Effect of Persistent Organic Pollutants on the Mortality of Marine Copepods (유기오염물질의 복합독성이 요각류 사망률에 미치는 영향)

  • Kang, Jung-Hoon;Kim, Woong-Seo
    • Ocean and Polar Research
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    • v.28 no.1
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    • pp.45-56
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    • 2006
  • This study investigated primarily the toxic effects of bis(tributyltin)oxide (TBT) and DDT (Dichlorodiphenyltrichloroethane) on the mortality of adult Acartia omorii and barnacle nauplii as well as the hatching rate of A. omorii. Subsequently, compound effects of TBT and DDT on the mortality of immature copepods were tested in order to assess whether or not synergistic influence existed in the mixture of sublethal concentration of two pollutants. Mortality of adult A. omorii increased as exposure concentration of DDT increased in the range of from 0.0001 to 1ppm. Egg hatching rate of the copepod showed no distinctive difference in the range between 0.1 and 10ppm, while barnacle nauplii showed abnormal motility of their appendages in the range of 0.0001 to 1 ppm. Mortality of adult A. omorii increased as TBT concentration increased within the range of 1 and 10 ppb, whereas egg hatching rate of the copepod showed no linear response to the same exposure range. Moreover, copepod nauplii were almost motionless even though copepod eggs hatched under the exposure condition of TBT $(0{\sim}10 ppb)$ and DDT $(0{\sim}10 ppm)$, respectively, suggesting that the nauplii are hard to develop into adult stage. On the basis of the sublethal concentration less than the 24-h $LC_{50}$, 0.001 ppm (DDT) and 2 ppb (TBT) were selected to confirm the compound effects of two pollutants on the mortality of immature copepods. Mortality of immature copepods under the condition of mixture of the two pollutants was higher than that in the single exposure condition. This result seems to indicate that synergistic effects of sublethal toxicants can make a more hazardous effect on the survival of immature copepods even though the concentration of single toxicant is not lethal to copepods in the marine environment.

Ecotoxicological Effects of the Increased Suspended Solids on Marine Benthic Organisms (부유물질증가에 따른 저서성 해양생물의 독성평가에 관한 연구)

  • Yoon, Sung-Jin;Park, Gyung-Soo
    • Journal of Environmental Science International
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    • v.20 no.11
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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.

A Study on the Behavior Change of Zebrafish For Toxicity Evaluation of Residual Psychoactive Medication in Wastewater Treatment Plant Effluent (하수처리시설 방류수 내 잔류 향정신성 의약품의 독성평가를 위한 zebrafish의 행동성 변화 연구)

  • Yoon, Hyojik;Kim, Minjae;Kim, Jongrack;Kim, Sungpyo
    • Journal of Korean Society on Water Environment
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    • v.35 no.6
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    • pp.574-579
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    • 2019
  • As interest in health issues increases, it is imperative to ensure good water quality from wastewater treatment plant effluent to preserve environmental health. In particular, currently there is a lack of water ecosystem risk assessment on pharmaceutical substances remaining in effluent. In this study, antidepressant escitalopram (ESC), antiepileptic carbamazepine (CBZ) and lead, which impact the behavior of aquatic organisms, were used to test their impact on the potential behavior of zebrafish. Zebrafish have been widely used in toxicological assessment studies due to the ease of handlinggenerically and genetically. It was possible to observe changes in the growth of organisms through monitoring the embryos' cognitive and behavior assessment. In this study, the embryo lethal dose test showed that the lethal concentration of ESC and CBZ was at 10 ppb, which is below the water quality criterion (100 ppb), increased by 32.5 % and 40 %, respectively. In the cognitive test, it was found that the cognitive ability function decreased by 22 % and 17% for ESC(500 ppb) and CBZ(1,000 ppb) respectively relative to control. Based on these results, it is necessary to initiate efforts to remove these trace pollutants from sewage treatment facilities to protect the health of aquatic organisms.

Acute Toxicity of Chlorine Dioxide (ClO2) to Juvenile Black Seabream Acanthopagrus schlegelii and Red Seabream Pagrus major (감성돔(Acanthopagrus schlegelii) 및 참돔(Pagrus major) 치어에 대한 이산화염소(ClO2)의 급성 독성)

  • Lee, Ock;Seo, Junhyuk;Seo, Hyoungwon;Jang, Dahee;Lee, Jaeman;Choi, TaeGun;Park, Jeonghwan
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.53 no.3
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    • pp.451-455
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    • 2020
  • This study evaluated acute toxicity of chlorine dioxide (ClO2 ) to juveniles of black seabream Acanthopagrus schlegelii (19.4±2.3 g, 10.7±0.4 cm) and red seabream Pagrus major (74.9±8.2 g, 15.9±1.0 cm). Thirty juveniles for each species were exposed to target ClO2 concentrations of 0, 0.05, 0.1, 0.125, 0.15, 0.2, 0.3, 0.4, and 0.5 mg/L in triplicate for eight days. Half lethal concentrations for 96 hours were found at 0.14 and 0.24 mg ClO2/L for black seabream and red seabream, respectively. Red seabream larger than black seabream in body weight appears to be more resistance to chlorine dioxide. However, regardless of species or size, specific loading rates of chlorine dioxide to total fish weight (daily feeding amount of ClO2/total fish weight) were similar, showing 1.3 and 1.1 g ClO2/kg fish·day-1 for black seabream and red seabream.

Physiological Genetic Studies on the Erects of Methyl methanesulfonate in Drosophila melanogaster (Drosophila melanogaster에 있어서 Methyl methane sulfonate의 영향에 대한 생리유전학적 연구)

  • 최혜영;최영현
    • Journal of Environmental Science International
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    • v.6 no.1
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    • pp.45-52
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    • 1997
  • Methyl methanesulfonate (MMS) was fed to Drosophila melnogaster in order to investigate its toxic capability at developmental and adult stages, and the hereditary effect of toxicity and the potency for induction of sex-linked lethal mutation during the slyer-matogenesis by the means of an attached-X method. In the control group, the egg to adult viability of D. melnogaster was 95.2%, while 3. 5mM and 5.0mM treated groups were 90.0% and 84.1%, respectively. In the case of their progenies (Fl), the viability was 96.9% in the control group, while 3.5mM and 5.0mM treated groups were 54.5% and 1.6%, respectively. Therefore, these differences between two generations show significant physiological toxic effects in the next generation. In the parental generation, the developmental time was calculated 11.05 days in the control group, 12.43 days In 3.5%mM treated group, and 13.23 days in 5.0mM. In the case of Fl it was estimated 10.35 days in the control group, and 11.43 days In 3.5mM treated group. Compared with the control groups In two generations, the developmental time generally delayed as the dose of MMS increased. As to the sex-ratio, there was no differences between the control and MMS treated groups. The toxic values of adult stage showed which increased the frequency of mortality with MMS concentrations. The mortality at 120hr In the control group was 1.67% and it in 0.5mM MMS treated group 3.33%. In 2.5mM MMS treated group, it was 33.3% at 72hr, and it 95% at 120hr The increase of the morality was shown from 72hr in 4.0mM treated group which was 100% at 96hr. There was the concentration-dependent induction of sex-linked lethal mutation during the spermatogenesis by means of an attached-X method, MMS had more pronounced effect in sperm and spermaid stages in D. melnogaster.

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Influence of Heavy Metals, Ammonia, and Organotin Compounds on the Survival of Arkshell Clams, Scapharca broughtonii (중금속, 암모니아, 유기주석화합물이 피조개 (Scapharca broughtonii) 의 생존에 미치는 영향)

  • Kim, Chan-Kook;Kim, Dong-Hoon;Lee, Jung-Suk;Lee, Kyu-Tae
    • The Korean Journal of Malacology
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    • v.20 no.1
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    • pp.93-105
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    • 2004
  • Arkshell clams, Scapharca broughtonii, are economically important edible bivalves and widely cultivated in the Southern coast of Korea. Recently, the production of S. broughtonii has been dramatically decreased and various reasons including chemical pollution were suspected to be related to the production declines. However, it remains unknown whether the chemical pollution levels of the surrounding environments were high enough for the biological and ecological disturbance for the population of S. broughtonii, because no systematic toxicological study using S. broughtonii has been conducted previously. In the present study, we exposed arkshell clams, S. broughtonii to various waterborne pollutants including heavy metals (Cd, Cu and Hg), ammonia and organotins (tributyltin and triphenyltin) to determine the effect concentrations of these pollutants for the survival of S. broughtonii for 20 days. The median lethal concentrations ($LC_50$) of S. broughtonii were 2.1 mg/l for Cd, 0.065 mg/l for Cu, 0.40 mg/l for Hg, 79.4 mg/l for total ammonia (1.9 mg/l for unionized ammonia), 0.5 ${\mu}$g/l for TBT, and 14${\mu}$g/l for TPhT. Lethal toxicity of the most pollutants increased with both exposure duration and concentration. The toxicity of TBT was greatest for S. broughtonii, followed by TPhT > Cu > Hg > Cd > ammonia. The sensitivities of S. broughtonii to heavy metals and TBT were comparable to those of other aquatic organisms, but they were relatively tolerable to ammonia. The environmental concentrations of the tested pollutants were compared with the effect concentrations of those for the survival of S. broughtonii to assess the potential risks of the pollutants in the field conditions.

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