• Korean Journal of Ecology and Environment
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• v.50 no.4
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• pp.374-380
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• 2017

Pine wilt disease (PWD) is one of the hazardous pine tree diseases in whole world. In Korea, PWD has been spreading since it was first observed in Busan in 1988. Dispersion of PWD is mainly mediated by its vectors such as Japanese pine sawyer. In this study, we characterized environmental condition including meteorological factors, geographical factors, and land use factors influencing on the occurrence of PWD. The occurrence data of PWD were collected at 153 sites where were the initial occurrence sites of PWD in local government regions such as city, Gun, or Gu scale. We used Akaike Information Criterion (AIC) to evaluate the relative importance of environmental variables on the discrimination of occurrence or absence of PWD. The results showed that altitude, slope, and distance to road were the most influential factors on the occurrence of PWD, followed by distance to building. Finally, our study presented that human activities highly influenced on the long term dispersal of PWD.

• Journal of Environmental Science International
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• v.14 no.1
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• pp.9-14
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• 2005

This study evaluated the hazard caused by $NO_{2}$, an oxidant generated in the process of welding. We com­pared hematological and biochemical parameters in workers who chronically inhale $NO_{2}$ and office workers not exposed to $NO_{2}$. $NO_{2}$ exposure affected the hematological and biochemical parameters. Increasing $NO_{2}$ concen­trationincreased the number of leukocytes, while decreasing the number of erythrocytes. Blood urea nitrogen, cre­atinine, uric acid, and lactate dehydrogenase were increased, while total protein and triglycerides were decreased. The mean concentration of $NO_{x}(NO_{2}^{-}/NO_{3}^{-})$ in the serum of welders and the control group was $35.97{\pm}2.85\;and\;55.40{\pm}5.81\;{\mu}mol/L,$ respectively. The difference was significant (p < 0.05), although $NO_{2}^{-}$ was not detected in the serum.

• Fire Protection Technology
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• s.10
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• pp.19-26
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• 1991

This reoprt intended to apprehend the principle for combustible phenomena in the environments and the prediction of its hazard in the virtual fire. So we first explained the basic machanism for the combustion, and discovered the tendency of the conbustion in the condition of the environmental factors(Humidity, Wind, Temperature) by means of some sxperiments about the wood as example.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.2 no.2
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• pp.9-23
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• 1999

Pusan's reputation as the nation's most crowded city in terms of population density is attributable to its huge mountains which allow only small portion of residential area to its large population. Rapid increase of urban population on limited amount of land had naturally led its developments efforts to mountainous area giving rise to the concern of potential landslide. This study on urban Pusan and "Landslide Hazard Map" thereof is prepared in an attempt to avoid disasters created by landslide and also as a reference for city planners. The Map shows that the area covering 38% to 43% of urban Pusan has the potential for landslide. The study also shows that various civil works involving massive land excavation had been more direct cause of landslides in Pusan than such traditional factors as locations, ground slopes, rock types and topography of the area concerned.

• Journal of The Korean Society of Agricultural Engineers
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• v.49 no.3
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• pp.63-68
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• 2007

The LRA(Logistic Regression Analysis) conducts a quantitative analysis by collecting a lot of samples and the AHP(Analytic Hierarchy Program) makes use of expert decision influenced by subjective judgment to a certain degree. This study is to suggest a combination method in mapping landslide hazard by giving equal weight for the result of LRA and AHP. Topographic factors(slope, aspect, elevation), soil dram, soil depth and land use were adopted to classify landslide hazard areas. The three methods(LRA, AHP, the combined approach) was applied to a $520km^2$ region located in the middle of South Korea which have occurred 39 landslides during 1999 and 2003. The suggested method showed 58.9% matching rate for the real landslide sites comparing with the classified areas of high-risk landslide While LRA and AHP Showed 46.1% and 48.7% matching rates respectively. Further studies are recommended to find the optimal combining weight of LRA and AHP with more landslide data.

• The Journal of Engineering Geology
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• v.19 no.3
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• pp.295-306
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• 2009

The risk assessment of groundwater and soil in Sasang industrial complex in Busan Metropolitan City was carried out in order to estimate risks to human health and the environment. The carcinogenic risk (CR) of receptors to soil and air was not identified. However, the CRs for TCE and PCE were 6.7E-6 and 1.0E-5, respectively. Hazard quotient (HQ) and hazard index (HI) did not appear through air exposure pathways. Yet the HQ and HI of soil were 3.4E-5 and 5E-5, respectively, and lower than the critical value (1.0). On the contrary, HQ and HI with respect to groundwater were calculated as 0.7 (not hazardous) and 1.4 (hazardous). The constituent reduction factor (CRF) for TCE in the study area was determined as 2.5, and thus remediation work is demanded. As a result of sensitivity analysis for 18 exposure factors, eight exposure factors (life time of carcinogens, age, body weight, exposure duration, exposure frequency, dermal exposure frequency, water ingestion rate, and soil ingestion rate) varied with the variation of risk.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.14
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• pp.6105-6109
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• 2015

Background: Colorectal cancer (CRC) is one of the most common cancers worldwide. This study aimed to investigate the risk factors for colorectal cancer in the Thai population. Materials and Methods: A cohort study was carried out in Khon Kaen, Thailand, including 71 cases of histologically confirmed CRC patients among 19,861 participants, aged 30-69 years, who were recruited for a cohort study during the period 1990-2001. Participants were followed-up until 31 December, 2013. To identify factors associated with the incidence of colorectal cancer, hazard ratios were evaluated using Cox proportional hazard regression. Results: No environmental variables could be shown to be significantly related to the risk of CRC. Although in our sample, CRC was more prevalent among males, ex-smokers, and those who drank alcohol beverages ${\geq}50gram/day$, but we could not demonstrate significantly associations (HRmale= 1.67, 95% CI, 0.80-3.49, HR ex-smokers = 1.34, 95% CI, 0.52-3.46, and HRalc ${\geq}50=1.08$, 95% CI, 0.43-2.71). Individuals within the sample with a family history of cancer, working hour >8 hours per day, and current-smokers appeared to have decrease risk of CRC, but again these relationship could not be shown to be significantly associated (HRfam cancer= 0.96, 95% CI, 0.85-1.09, HRwork>8= 0.84, 95% CI, 0.36-1.93, and HRcurrent-smoker = 0.51, 95% CI, 0.18-1.38). Conclusions: We found no evidence of environmental factors effecting the risk of CRC. There is a need for further research to determine why factors identified risk in other populations appear to not be associated with CRC risk in Thais.

• Journal of environmental and Sanitary engineering
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• v.14 no.4
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• pp.41-49
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• 1999

The water treatment by was performed to remove VOC and organic substances in the multi-stage ozone contactor. Ozone is mainly utilized to change the chemical structures of organic substance, of which finally has the purpose to degrad them. The removal efficiency of VOC has 20~60% at the ozone concentration of 3 ppm, in case of trichloroethylene, its efficiency is reduced by 85% at the ozone contact time of 8 min. Design factors such as the number of stage, ozone concentration, zone contact time are determined for optimal treatment in the multi-stage contactor.

• Journal of Environmental Health Sciences
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• v.44 no.4
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• pp.340-347
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• 2018

Objectives: This study was performed to determine environmental hazard factors and provide more eco-friendly child activity spaces within children's playgrounds installed in Gyeonggi-do Province. Methods: Basic (XRF) and precise (ICP, UV) inspections were conducted. The test items examined were heavy metals and parasite eggs. As a sampling point, painted finish materials (180), synthetic rubber (50), and sand (50) were selected. Results: The total excess rate of heavy metals in the XRF was found to be 7.4% (17/230 points). In a comparison between the basic and precise inspections with 17 excess points, the concentration deviation between the two tests was found to be from 0.01 to 7.7 times, resulting in a large difference. Furthermore, all the excess samples were dual samples. However, the contribution rates of Pb and $Cr^{6+}$ to combined concentration were found to be 85.1 and 14.9% for basic inspection and 91.9 and 8.1% for precise inspections, so there is a similar tendency between the two tests. The excess rate of parasite eggs in sand was expressed at 6%. The excess rate of heavy metals in synthetic rubber was found to be 0%. Conclusion: The reliability of the XRF is low. However, considering the contribution rate of Pb and $Cr^{6+}$ between the two tests, it is likely to be applicable for screening. Dual samples provided high concentrations and excess samples and care should be taken when managing them.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.2
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• pp.211-218
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• 1993

Landslides, failure of slope stability by natural or artificial factors, occur loss of life and properties. Recently, statistical methods and field measurements are used to a study for prediction of landslide harzard area, but there are so many difficulties to find the occurence system because of its complexity. In this study, authors choose the model area where occured landslides to predict the landslide hazard. Authors made a database of ground height to compare the each topography by scale of 1 : 25,000, 1 : 10,000, 1 : 5,000 and 1 : 1,200. Authors predict to landslide hazard area by the weight of ground height data and slope angle data. Finally, authors could know the possibility of prediction to find the landslide hazard partly.