• Microbiology and Biotechnology Letters
• /
• v.36 no.4
• /
• pp.336-342
• /
• 2008

The effect of methyl tert-butyl ether (MTBE) and its metabolites like tert-butyl alcohol (TBA), and formaldehyde (FA) on microbial activity and diversity in tidal mud flat was studied. MTBE, TBA, and FA with different concentrations were added into microcosms containing tidal mud samples, and placed at room temperature for 30 days. Then the physico-chemical properties such as pH, moisture contents and organic matter contents in the microcosms were measured. In addition, the total viable cell number and dehydrogenase activity were measured. Bacterial communities in the microcosms were monitored using a 16S rRNA-PCR-DGGE (Denaturing gradient gel electrophoresis) fingerprinting method. As a result, the exposure concentrations of MTBE and its metabolites showed no correlation with the physico-chemical factors (P>0.05). Dehydrogenase activity and total viable cell number were decreased with increasing MTBE, TBA and FA concentrations (P<0.05). The toxic effect was higher the following order: FA > MTBE > TBA. Dominant species in the microcosms contaminated with MTBE and its metabolites were Sphingobacteria, Flavobacteria, delta-proteobacteria, gamma-proteobacteria. The diversity of bacterial community was not significantly influenced by MTBE and its metabolites.

• Korean Journal of Environmental Biology
• /
• v.20 no.2
• /
• pp.158-164
• /
• 2002

Some of synthetic chemicals can net as an endocrine disrupting substance in higher animals. Dioxins, DDT, PCBs and bisphenol A (BPA) are classified into endocrine disruptors and aye under a strict control in many countries. This research was designed to compare the clastogenic effects of BPA to those of ionizng radiation to establish the relaltive effectiveness of BPA by means of Tradescantia micronucleus assay. For the uptake of the BPA through the stems, groups of fresh cuttings of Tradescantia BNL 4430 weve placed in BPA solutions of 0 to 4 $\mu$M for 6 hours under continuous aeration. The other groups of the cuttings were irradiated with 0 to 0.5 Gy of gamma- rays. The frequencies of micronucleus showed a positive dose- response relationship in the range of 0 to 0.5 Gy, and a clear concentration-response relationship in the experimental range of BPA concentrations. By comparing the two experimental results, it is possible to estimate the BPA concentration and its equivalent radiation dose for a fixed value of MCN frequency. BPA of $ll.8\mu{M}$ can give rise to 53.3 MCN/100 tetrads, which is the same frequency induced by 25 cGy of gamma- rays. It is of biological importance that clinical symptoms start to develop after a whole body exposure to radiation higher than 25 cGy. The results indicate that the pollen mother cells are an excellent biological end- point for toxicity test of suspected endocrine disrupting chemicals such as bisphenol A, cotylphenol and nonylphenol.

• Korean Journal of Environmental Biology
• /
• v.20 no.2
• /
• pp.136-145
• /
• 2002

A laboratory microcosm experiment was conducted to evaluate a major metal uptake route as well as chronic toxic effects of the clam, Macoma balthica exposed to Ag and Cu contaminated sediments. Twenty five clams were exposed to the sediments contaminated with four levels of Ag $Ag(0.01-0.87\mu{mol}\;g^{-1})$ and $Cu(0.75-5.55\mu{mol\;g^{-1})$ for 90 days. AVS (acid volatile sulfide) concentration in the sediments, considered as major factor controlling metal geochemistry and bioavailability, was manipulated to evaluate its effects on Ag and Cu bioaccumulation in M. balthica. Following 90-d exposure, the tissue Ag and Cu in M. balthica increased linearly with the Ag and Cu concentrations in sediments extracted with 1 N HCI (SEM, simultaneously extracted metals with AVS). The bioaccumulation of Ag and Cu in M. balthica was little influenced by difference in [SEM] - [AVS] values, suggesting a minor contribution of pore water metals to bioaccumulation. Tissue Ag and Cu concentrations directly influenced on the clearance rate and glycogen content of the clams. The clams with highest tissue Ag $(1.0\pm{0.2}\mu{mol}\;g^{-1})$ and Cu concentrations $(2.7\pm{0.3}\;\mu{mol}\;g^{-1})$ had only 18-43% of clearance of the clams exposed to uncontaminated sediments. Similarly, glycogen content of the exposed clams had a inverse relationship with tissue Ag and Cu concentrations. These results suggest that M. balthica exposed to Ag and Cu contaminated sediments accumulates metals largely by ingestion of contaminated sediments and can display chronic effects as reduced clearance rate and glycogen content.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.19 no.6
• /
• pp.87-100
• /
• 2016

This research was performed for the purpose of providing useful and base data and preservation strategy of growth characteristics of Rhododendron micranthum. From the result of research, wild growth area of Rhododendron micranthum was discovered near steep forest road on 695~901m in altitude above sea level of Baekdu-daegan National Arboretum. Vegetation colony structure of Site I was resulted in Pinus densiflora(tree stratum M.I.P.=45.3%) is dominants, Betula schmidtii(arborescent M.I.P.=9.8%) is second dominant, and Site III resulted in Pinus densiflora(tree stratum M.I.P.=30.5%) is dominants, Betula schmidtii(arborescent M.I.P.=10.3%) is second dominant. Site II resulted in Betula schmidtii(arborescent M.I.P.=30.4%) is dominants and Pinus densiflora tree(tree stratum M.I.P.=8.3%) is second dominants. For herbs, it was researched that the rate of one year herb of chrysanthemum family(10), rice family(3), sedge(2) was higher than near forest area. Among Species diversity index, that of Shannon was in range of 0.7348~1.1090. After comparing this with similar area, this value was relatively low. Dominance analysis result was analyzed that various groups are evenly distributed. Monthly highest average temperature is $23.9^{\circ}$ in Site A and Site B, and monthly lowest average temperature is $-4.5^{\circ}C$ in Site I and $-4.7^{\circ}C$ in Site II. Monthly maximum average humidity is 85.6% in Site I and 83.2% in Site II. Monthly minimum average humidity is 60.9% in Site I and 60.8% in Site II and it showed that these 2 area are located far away but have similar temperature and humidity characteristic and climate environment is similar. It was analyzed that humidity is high with the result of annual average humidity is over 60%. In growth characteristic, it showed that doubt damage of Stephanitis pyrioides, exposure of roots, peeled bark was discovered and supplement on this is urgent.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.24 no.4
• /
• pp.39-48
• /
• 2016

An information management system for a solid waste landfill site was developed, in this study, to optimize the operation and management of solid waste landfill in real time in addition to provide the information of landfill status to the landfill operator, public official concerned and local residents. The landfill information management system is composed of two systems (Solid waste landfill history management system and landfill operation and performance management system). The solid waste landfill history management system based on automated RFID/LPR system allows landfill operators to provide information of waste collection vehicles and received waste. In addition, the system aids in the identification of 3-dimensional (3D) position for landfilled solid wastes. Using the landfill operation and performance management system based on 3D laser scanner delivers information about landfill volume, settlement, landfill density, and current landfill capacity to landfill operators in real time, resulting in optimum space utilization. Ultimately, this system would dramatically reduce exposure of landfill operators to hazardous materials and improve the productivity of landfill operations.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.12
• /
• pp.4809-4813
• /
• 2014

Endocrine-disrupting chemicals (EDCs) have been reported to interfere with estrogen signaling. Exposure to these chemicals decreases the immune response and causes a wide range of diseases in animals and humans. Recently, many studies showed that licorice (Glycyrrhiza glabra) root extract (LRE) commonly called "gamcho" in Korea exhibits antioxidative, chemoprotective, and detoxifying properties. This study aimed to investigate the mechanism of action of LRE and to determine if and how LRE can alleviate the toxicity of EDCs. LRE was prepared by vacuum evaporation and freeze-drying after homogenization of licorice root powder that was soaked in 80% ethanol for 72 h. We used 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) as a representative EDC, which is known to induce tumors or cancers; MCF-7 breast cancer cells, used as a tumor model, were treated with TCDD and various concentrations of LRE (0, 50, 100, 200, $400{\mu}g/mL$) for 24, 48, and 72 h. As a result, TCDD stimulated MCF-7 cell proliferation, but LRE significantly inhibited TCDD-induced MCF-7 cell proliferation in a dose- and time-dependent manner. The expression of TCDD toxicity-related genes, i.e., aryl hydrocarbon receptor (AhR), AhR nuclear translocator, and cytochrome P450 1A1, was also down-regulated by LRE in a dose-dependent manner. Analysis of cell cycle distribution after treatment of MCF-7 cells with TCDD showed that LRE inhibited the proliferation of MCF-7 cells via G2/M phase arrest. Reverse transcription-polymerase chain reaction and Western blot analysis also revealed that LRE dose-dependently increased the expression of the tumor suppressor genes p53 and p27 and down-regulated the expression of cell cycle-related genes. These data suggest that LRE can mitigate the tumorigenic effects of TCDD in breast cancer cells by suppression of AhR expression and cell cycle arrest. Thus, LRE can be used as a potential toxicity-alleviating agent against EDC-mediated diseases.

• Journal of Korean Society of Environmental Engineers
• /
• v.34 no.12
• /
• pp.828-834
• /
• 2012

The ecotoxicity detection device for preliminary test (Test jig) was manufactured to develop the biological early warning system using Vibrio fischeri. In this study, the ecotoxicity detection charateristics of the Test jig was investigated for 6 heavy metals (Cr, Zn, Pb, Cd, Cu and Hg). It was observed that relative luminescence unit (RLU) of Vibrio fischeri constantly decreased by the concentrations of the tested heavy metals. In contrast with other heavy metals, RLUs of Pb and Hg constantly decreased even at low concentrations. RLU of Hg drastically decreased when its concentration increased from 0.13 mg/L to 0.25 mg/L. $EC_{50}$ values of Cr, Zn, Pb and Cd gradually decreased with exposure time, whereas there was no significant change in $EC_{50}$ values of Cu and Hg with time. On the other hand, $EC_{50}$ values between the Test jig and Reference device were compared to evaluate the ecotoxicity detection performance of the Test jig. No big difference was found in $EC_{50}$ vlaues between the two devices, indicating that the Test jig could be applied as the ecotoxicity detection device for heavy metals.

• Environmental Analysis Health and Toxicology
• /
• v.24 no.2
• /
• pp.119-125
• /
• 2009

This study was carried out to investigate the toxic effect of WSF (water soluble fraction) in crude oil on the hatch, survival rate, abnormality and physiological activity of fertilized eggs and early larvae in Paralicthys olivaceus. The time required in hatching the fertilized eggs exposure to crude oil was 50.8${\sim}$53.2 hours both in control group and experimental group, showing no significant difference(p>0.05). The hatching rate in the control group was more than 80% in 1.9 ${\mu}g/mL$ WSF concentration, but hatching rate was less than 55.7% in below of 3.9 ${\mu}g/mL$ WSF concentration, showing significant difference (p<0.05). The survival rate on the 3rd day of early larval stage was 61.96% with 1.9 ${\mu}g/mL$ WSF, 11.1% with 3.9 ${\mu}g/mL$ WSF, and they all died with other concentration levels. The oxygen consumption rate in experimental groups was lower than control group. The heart rate (no./min) was 47.4${\sim}$52.8 before hatching and there was no significant difference between control group and experimental group, but heart rate reduced with the decrease of WSF concentration after hatching. The abnormality was 1.1% in the control group whereas 36.7% with 3.9${\mu}g/mL$ WSF, and abnormality was mostly comprised of incomplete spinal formation and spinal curvature. The results of this study suggest that even low concentration to WSF affects the early development of the flounder, Paralicthys olivaceus.

• Applied Biological Chemistry
• /
• v.27 no.1
• /
• pp.34-39
• /
• 1984

Environmental effects of light. temperature, and pH of culture media on mycelial growth and fruit-body formation of Flammulina velutipes in synthetic media were investigated. Illumination inhibited mycelial growth, but illumination during the latter part of vegetative growth induced primordia formation. The optimum light intensity and exposure time were $100{\sim}1000$ lux and $4{\sim}8$ hours per day, respectively. High intensity of light was injurous, and in darkness primordia developed into very poor fruit-bodies. The optimum temperature was $25^{\circ}C for mycelial growth and $15^{\circ}C$ for fruit-body formation. The optimum pH range for mycelial growth was found to be from 5.0 to 7.0 and for fruit-body formation from 5.0 to 6.0. In low temperature treatments, a temperature of $15^{\circ}C$ was more effective than $5^{\circ}C\;or\;10^{\circ}C$, it took about 12 hours for primordium formation, but at $5^{\circ}C\;or\;10^{\circ}C$ about 48 hours. The most excellent fruit-body formation were produced from the mycelium growth for 7 to 10 days.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.7
• /
• pp.2745-2749
• /
• 2015

Objective: To study the PLCE1 gene rs2274223 polymorphism with regard to esophageal cancer and its interaction with diet, lifestyle, psychological and environmental factors in Southwest Shandong province. Materials and Methods: A case series study (case-case) was conducted. Questionnaire data were collected and 3 ml-5ml venous blood was drawn for DNA extraction among the qualified research subjects. PLCE1 gene polymorphism was detected after PCR amplification of DNA. SPSS 13.0 software was used for statistical analysis of the data. Results: The three genotypes A/A, A/G and G/G PLCE1 gene rs2274223 was 31, 16 and 4 cases, accounting for 60.8%, 31.4%, 0.08% respectively. The difference of three genotypes (AA/GA/GG) proportion between negative and positive family history of patients was statistically significant, ${\chi}^2=6.213$, p=0.045. There was no statistically significant relationship between PLCE1 gene rs2274223 polymorphism and smoking, drinking, ${\chi}^2=0.119$, p=0.998, and ${\chi}^2=1.727$, p=0.786. There was no linkage of the three rs2274223 PLCE1 gene genotypes (AA/GA/GG) proportion with eating fried, pickled, hot, mildew, overnight, smoked, excitant food, eat speed, salt taste or not (p>0.05). or with living environment pollution and nine risk factors of occupational exposure (p>0.05). There was no statistically significant difference in TS scores between different genotype of rs2274223 PLCE1 gene. Conclusions: The PLCE1 rs2274223 polymorphism has a relationship with family history of esophageal cancer, but does not have any significant association with age, gender, smoking, alcohol drinking, food hygiene, eating habits, living around the environment and occupation in cases.