• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.5
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• pp.462-473
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• 2010

Inductions of hybrids and reciprocal hybrids between Oryzias dancena and O. javanicus (ODJ and OJD) were conducted and backcross hybrids between female O. dancena and male ODJ were also produced for biological and cytogenetic analysis. Embryonic development of ODJ and OJD were compared with those of their parents. Developmental time was fastest in O. dancena and ODJ, followed by O. javanicus and OJD. Oryzias dancena hatched 11 days (d) after fertilization, ODJ at 13 d, O. javanicus at 14 d and OJD at 15 d. The abnormality of external morphology rate in ODJ was 10.6%; however, OJD showed a high degree of abnormality, over 90%. The proportion of males was 90.0% and 31.3% for ODJ and OJD, respectively. Cytogenetic analysis was conducted to obtain basic information for genetic identification of O. dancena, O. javanicus and their hybrids. The karyotypes of all experimental groups showed 2n=48 chromosomes and the fundamental number (FN) was 48. The first pair carried secondary constrictions near the centromeric regions. Erythrocyte area and volume were $9.8\;{\pm}\;0.5\;{\mu}m^2$ and $18.2\;{\pm}\;1.0\;{\mu}m^3$, respectively, for O. dancena, $8.3\;{\pm}\;0.5\;{\mu}m^2$ and $15.8\;{\pm}\;1.5\;{\mu}m^3$ in O. javanicus, and $18.3\;{\pm}\;0.5\;{\mu}m^2$ and $15.7\;{\pm}\;1.3\;{\mu}m^3$ in ODJ. Erythrocyte area and volume in ODJ were similar to those of O. javanicus. In backcross hybrids between female O. dancena and male ODJ, all embryos failed to develop and died in the late gastrula stage.

• Korean Journal of Environmental Agriculture
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• v.42 no.2
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• pp.131-138
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• 2023

The biological half-life and dissipation rate of azoxystrobin in crown daisy were calculated to establish the pre-harvest residue limits (PHRLs). The pesticide residues were calculated after washing with five different processes to propose an effective process in the household and conducted a risk assessment to confirm dietary safety. Azoxystrobin was sprayed according to the critical good agricultural practices (cGAP) in two different field trials, and the samples were harvested 7 times. The limit of quantitation was 0.02 mg/kg, and the mean recoveries of azoxystrobin were within the range of 70~120% with below 20% coefficient variation at the concentration of 0.02 and 0.2 mg/kg . The biological half-lives were 7.4 and 4.7 days, and the dissipation rate constants were 0.0872 and 0.1217 in fields 1 and 2, respectively. The average removal rates were 58.13~78.13% by the different washing processes, and there were significant differences between the washing processes (one-way ANOVA analysis and post-hoc Duncan test, p-value<0.05). The residues of azoxystrobin in crown daisy were safe levels from farm to fork after application with the critical good agricultural practice (cGAP) registered in Korea.

• Toxicological Research
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• v.17
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• pp.25-35
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• 2001

In 1990, Tolerable Daily Intake (TDI) of 10 pg TCDD/kg/day for dioxins based on carcinogenicity and reproductive toxicity was determined by WHO/EURO, that resulted in the establishment of TDIs in other countries. In Japan, Ministry of Health and Welfare and Environment Agency, respectively established the TDI of 10 pg TCDD/kg/day and Health Risk Assessment Index of 5 pg TCDD/kg/day in 1996. Accumulation of new scientific data, especially by molecular toxicology since 1990, resulted in the reevaluation of TDI by WHO-ECEH and IPCS in May, 1998. At this meeting, it was stressed that \circled1 toxic effects of dioxin is mediated through Ah-receptor in both animals and humans, \circled2 use of ebody burdeni concept is better than the use of traditional NOAEL/UF approach, \circled3 inclusion of coplanar PCBs in the TDI by the use of new WHO-TEF. LOAELs (0.16~200 ng TCDD/kg/day) obtained from reproductive toxicity and immunotoxicity in rats, and neurobehavioral toxicity and induction of endometriosis in rhesus monkeys are calculated to be the body burden of 10~50 ng TCDD/kg that is 14~37 pg TEQ/kg/day as human daily intake. Finally TDI of 1~4 pg TEQ/kg/day was established by applying the UF of 10. In Japan, reproductive toxicity and immunotoxicity in rats were used to obtain LOAELs (100~200 ng TCDD/kg/day). Finally TDI of 4 pg TEQ/kg/day was established in June 1999 by applying the UF of 10 to human daily intake of 43.6 pg TEQ/kg/day which corresponds to the body burden of 86 ng TCDD/kg.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.25-39
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• 2003

Risk and exposure assessment for subsurface environment is very important for both aspects of health and environmental protection as well as making decision of remedial goal for engineering activities. Exposure due to hazardous chemicals in the subsurface environment is essential to assess risk lev121 to individual person, especially from soil and groundwater environmental media. In this paper, the status of soil and groundwater contamination is presented to discuss on the problem for environmental risk assessment. The methodologies of fate and exposure models are also discussed by conducting the case studies of exposure assessment for heavy metals, organic compounds, and dioxin compounds. In addition, the structure of exposure models and available data for model calculation are examined to make clear more realistic exposure scenarios and the application to the practical environmental issues. Three kinds of advanced remediation techniques for soil and groundwater contamination are described in this paper, The most practical method for VOCs is the bio-remediation technique in which biological process due to consortium of microorganisms can be applied. For more effective remediation of soil contaminated by heavy metals we have adopted the soil flushing technique and clean-up system using electro-kinetic method. We have also developed the advanced techniques of geo-melting method for soil contaminated by DXNs and PCB compounds. These techniques are planed to introduce and to apply for a lot of contaminated sites in Japan.

• Health Policy and Management
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• v.17 no.3
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• pp.87-105
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• 2007

The purpose of this study was to analyze whether nonemergency, isolated coronary artery bypass graft (CABG) surgery for high- or low-risk patients biases the assessment of the risk-adjusted mortality rates of hospitals. This study used 2002 National Health Insurance claims data for tertiary hospitals in Korea. The study sample consisted of 1,959 patients from 23 tertiary hospitals. The risk-adjustment model used the patients' biological, admission, and comorbidity data identified in the claims. The subjects were classified into high- and low-risk groups based on predicted surgical risk. The crude mortality rates and risk-adjusted mortality rates for low-risk, high-risk, and all patients in a hospital were compared based on the rank and the four intervals defined by quartile. Also, the crude mortality rates of the three groups were compared with their 95% confidence intervals of predicted mortality rates. The C-statistic (0.83) and Hosmer-Lemeshow test ($X^2$=11.47, p=0.18) indicated that the risk-adjustment model performed well. Presenting crude mortality rates with their 95% confidence intervals of predicted rates showed higher agreements among the three groups than using the rank or intervals of mortality rates defined by quartile in the hospital performance assessment. The crude mortality rates for the low-risk patients in 21 of the 23 hospitals were located on the same side of their 95% confidence intervals compared to that for all patients. High-risk patients and all patients differed at only one hospital. In conclusion, the impact of risk selection by hospital on the assessment results was the smallest when comparing the crude inpatient mortality rates of CABG patients with the 95% confidence intervals of predicted mortality rates. Given the increasing importance of quality improvements in Korean health policy, it will be necessary to use the appropriate method of releasing the hospital performance data to the public to minimize any unwanted impact such as risk-based hospital selection.

• Applied Biological Chemistry
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• v.47 no.1
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• pp.1-16
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• 2004

The purpose of this paper is to review the occurrence, analytical methods and reduction methods of aflatoxins in foods. Aflatoxins are produced by the secondary metabolism of various fungal species and have the highest toxicity among mycotoxins. Due to their toxicity including carcinogenic activity, aflatoxins affect not only the health of humans ana animals but also the economics of agriculture and food. As a food-importing country, because aflatoxins could contaminate raw commodities and foodstuffs, there should be inspection on the exposure and the regulation of risk assessment as a food safety measure. In addition, studies on rapid analytical methods and reduction of toxicity by various processes for aflatoxins should be carried out in conjunction with those of the risk assessment of aflatoxins.

• Journal of Environmental Health Sciences
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• v.40 no.3
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• pp.187-203
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• 2014

Objectives: As the demand to deal with pathogens in domestic research institutions has expanded and biological accidents have increased, the need for systematic biosafety management in infectious disease laboratories has grown. According to international standards, risk assessment (RA) is required for biosafety management. However, RA criteria have not been clearly established in Korea, so to this end I have attempted to determine RA criteria meeting international levels Methods: In order to provide RA criteria for application, I analyzed the RA criteria in use in the U.S., Europe and at international organizations. In order to ensure the public nature of the RA criteria, I constructed the research model through modified management consulting methodology reflecting the model of Radnor and O'Mahoney. Results: According to the results of the study, existing laboratory biosafety regulations were comparable to domestic laboratory safety laws. Existing laboratory biosafety standards that are designed around risk factors were found to be insufficient. An RA case to be carried out in infectious disease laboratories at the National Institute of Health of KCDC was identified. Conclusion: To establish a systematic risk management system meeting international standards, it was necessary first to harmonize the systems of national and international standards. In addition, in order to provide specific biosafety management on-site, I recognized a need for methodology and planning strategies to discover biosafety management so that it can be carried out as required through the RA of individual laboratories.

• Environmental Analysis Health and Toxicology
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• v.23 no.4
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• pp.231-245
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• 2008

Various methods for detecting changes in response behaviors of indicator specimens are presented for monitoring effects of toxic treatments. The movement patterns of individuals are quantitatively characterized by statistical (i.e., ANOVA, multivariate analysis) and computational (i.e., fractal dimension, Fourier transform) methods. Extraction of information in complex behavioral data is further illustrated by techniques in ecological informatics. Multi-Layer Perceptron and Self-Organizing Map are applied for detection and patterning of response behaviors of indicator specimens. The recent techniques of Wavelet analysis and line detection by Recurrent Self-Organizing Map are additionally discussed as an efficient tool for checking time-series movement data. Behavioral monitoring could be established as new methodology in integrative ecological assessment, tilling the gap between large-scale (e.g., community structure) and small-scale (e.g., molecular response) measurements.

• Journal of Environmental Health Sciences
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• v.49 no.2
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• pp.108-117
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• 2023

Background: When particles are absorbed into the human body, they penetrate deep into the lungs and interact with the tissues of the body. Heavy metals in PM_2.5 can cause various diseases. The main source of PM_2.5 emissions in South Korea's atmosphere has been surveyed to be places of business. Objectives: The concentration of heavy metals in PM_2.5 near the Ulsan Industrial Complex was measured and a health risk assessment was performed for residents near the industrial complex for exposure to heavy metals in PM_2.5. Methods: Concentrations of heavy metals in PM_2.5 were measured at four measurement sites (Ulsan, Mipo, Onsan, Maegok) near the industrial complexes. Heavy metals were analyzed according to the Air Pollution Monitoring Network Installation and Operation Guidelines presented by the National Institute of Environmental Research. Among them, only five substances (Mn, Ni, As, Cd, Cr⁶⁺) were targeted. The risk assessment was conducted on inhalation exposure for five age groups, and the excess cancer risk and hazard quotient were calculated. Results: In the risk assessment of exposure to heavy metals in PM_2.5, As, Cd, and Cr⁶⁺ exceeded the risk tolerance standard of 10^-6 for carcinogenic hazards. The highest hazard levels were observed in Onsan and Mipo industrial complexes. In the case of non-carcinogenic hazards, Mn was identified as exceeding the hazard tolerance of 1, and it showed the highest hazard in the Ulsan Industrial Complex. Conclusions: This study presented a detailed health risk from exposure to heavy metals in PM_2.5 by industrial complexes located in Ulsan among five age groups. It is expected to be utilized as the basis for preparing damage control and industrial emission reduction measures against PM_2.5 exposure at the Ulsan Industrial Complex.

• Korean Journal of Plant Resources
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• v.32 no.5
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• pp.543-558
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• 2019

This study was carried out to apply the taxonomic characters to identify and to provide the habitat circumstances for forty one un-introduced environmentally harmful plants in the Korea which have been designated by Ministry of Environment in 2016. We investigated the dried plant specimen from several herbaria and performed field habitat survey in western coast area of United States including California, Oregon and Washington. We suggest the first result for ecological risk discussion, weed risk assessment, taxonomic characters and classification keys for 8 species with the related species - Carduus acanthoides L. (Asteraceae), Carduus tenuiflorus W. Curtis (Asteraceae), Onopordum acanthium L. (Asteraceae), Chromolaena odorata (L.) R.M. King & H. Rob. (Asteraceae), Hydrocotyle ranunculoides L.f. (Apiaceae), Oenanthe pimpinelloides L. (Apiaceae), Ehrharta erecta Lam. (Poaceae), and Paspalum conjugatum P.J. Bergius (Poaceae).