• Journal of the Korean GEO-environmental Society
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• v.16 no.8
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• pp.21-35
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• 2015

Electrical resistivity survey (2D and 3D) were employed for detection of possible weak zone of core zones of three central core earth-rockfill dams in Korea. In the 2D results, the core zones is lower resistivity zone with less than $50{\sim}400ohm{\cdot}m$, and the basement is relatively higher resistivity zone with over $1,000ohm{\cdot}m$. In the 3D results, especially, the weak zone with under $100ohm{\cdot}m$ was detected spatial distribution area in the dam. We also drilled boreholes to collect soil samples of core zones of each dam. Water was not used during boring, because water for rotary wash boring could cause structural damages in earth dams. We found that the soil samples of core zones from all of the boreholes correspond to CL (USCS), but we also found that the fluidized or water-saturated soil samples were found in lower resistivity zones. Therefore, the electrical resistivity survey and drilling method without water are a quick and efficient method for structural-health evaluation which is detection of possible weak zones in earth core rockfill dams.

• Journal of environmental and Sanitary engineering
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• v.10 no.1
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• pp.66-75
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• 1995

This survey is executed about the water quality and improvement measure of Imjin- river. The results are summarized as follows; 1 ) Ammonia nitrogen concentration in tap water was two times higher than drinking water standard. 2) The concentration of BOD in textile wastewater was 235ppm which is higher than wastewater distribution standard and leather wastewater showed high nitrogen concentration. 3) Water quality of the Imjin- river upstream was not in problem but that of Shin- stream showed somewhat high concentration in BOD, COD, and ammonia nitrogen. Especially the detected Cynide compound on the lower of Shin- stream implied seriously polluted condition. 4) The heavy metal in soil of the river bed was not detected but iron, zinc was detected to high concentration. 5) It Is urgently suggested to build more municipal sewage and sanitary treatment plants, and run dredging and river bed rearrangement project. 6) The Construction of the wastewater treatment complexes of relevant industries shall be propelled as soon as possible.

• Journal of Ocean Engineering and Technology
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• v.5 no.1
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• pp.35-44
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• 1991

This study was carried out for the purpose of pre-estimating long-term settlement under condition of actual field soil's property, in case of building up industrial sites on the marine deposit silty clay located at West Coast in Korea. This study analyzed Hyperbolic Method, Square Root Time Method and Exponential Function Method with utilization of measured survey values of settlement in In-Cheon Namdong Industrial Sites. In the future, for the continuos utilization, it seemed to be needed that further the survey values of fields should be accurartely measured for the analysis of more accurate pre-estimate about long-term settlement. Among the prediction methods of settlement Hyperbolic Method seemed to be the best fitting method for measured data. The settlement equations were derived from above three methods, for long-term settlements.

• Journal of Korea Association of Health Promotion
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• v.1 no.1
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• pp.34-37
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• 2003

The NGO program of "intestinal parasite Control among primary Schoolchildren of Lao PDR", supported by KOICA and implemented by KAHP, has started in 1999 and will be executed until 2004. Under cooperation of the LAo Ministry of Health, WHO, Korean Embassy and KOCIA, for the last 4 years, KHIP has conducted parasitological survey throughout the country, supply of medical equipment and anti-helminthics and treatment of positive people. The results of the survey is as below : A total of 29,846 stool specimens were collected from primary schoolchildren from May 2000 to June 2002 and examined once with the cellphone thick smear. By species, the rate for Ascaris lumbricoides was 34.9%, hookworm 19.1%, Trichuris trihiura 25.8%, Opisthorchis iverrini 10.9%, Taenia spp. 0.6% and Hymenolepis spp. 0.1%. The northern mountainous regions showed a higher prevalence of soil-transmitted helminths. The regions along the Mekong River such as Khammuane, Saravane or Svannakhet Province showed a higher prevalence of fish-borne parasites.

• Journal of Environmental Science International
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• v.31 no.9
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• pp.757-766
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• 2022

This study is to examine how well the hydrologic model reproduces the dam collapse. To do this, A hydrologic model FLO-2D is being operated to reproduce dam collapse with rainfall data and surface data in a small dam. In order to examine the performance of the model, the simulation was compared and reviewed with the data collected through the field survey. The results show that it takes about 2 hours to reach 1 km downstream. Inundation areas are about 188,640 m2 by the simulation and the difference from the field investigation is about 6.1%. Ten representative points were selected from the areas where the simulation and the field survey did not match. The discrepancy is less than about 0.08 m and does not appear to be significant. This study will present basic information on disaster preparedness operation and planning to minimize damage caused by sudden collapse of agricultural soil dams in the future.

• Journal of Soil and Groundwater Environment
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• v.20 no.6
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• pp.73-84
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• 2015

Nine plant species were selected through vegetation survey at three military shooting ranges at northern Gyeonggi Province. Plants were germinated in normal soil and three seedlings were transplanted to a bottom sealed pot containing sandy loam soils contaminated with either RDX (291 mg/kg) or TNT (207 mg/kg). Planted, blank (without plant), and control (without explosive compound) pots were grown in triplicate at a green house for 134 days. During cultivation, transplanted plants exhibited chlorosis and necrosis in flower and leaf by explosive toxicity and stress. Only three plants, Wild soybean, Amur silver grass, Reed canary grass, survived in TNT treated pot, while seven plant species except for field penny cress and jimson weed, thrived in RDX treated pot. Appreciable amount of TNT (61.6~241.2 mg/g-D.W.) was detected only in plant roots. Up to 763.3 mg/g-D.W. along with 4-amino-2,6-dinitrotoluene, an intermediate of TNT, accumulated in the root of wild soybean. In addition, azoxy compounds, abiotic intermediates of TNT, were detected in TNT treated soils. RDX absorbed average 1,839.95 mg/kg in shoot and 204.83 mg/kg in root. Most of TNT in plant was accumulated in underground part whereas RDX was localized in aerial part. Material balance calculation showed that more than 95% of the initial TNT was removed in the planted pots whereas only 60% was removed in the blank pot. The amount of RDX removed from soil was in the order of Amur Silver Grass (51%) > Chickweed (43%) > Evening primrose (38%). Based on the results of pot cultures, Amur silver grass and Reed canary grass are selected as tolerant remedial plants for explosive toxicity.

• Journal of Environmental Health Sciences
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• v.48 no.4
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• pp.227-235
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• 2022

Background: Abandoned metal mines are classified as vulnerable areas with the highest level of soil contamination among risk regions. People living near abandoned metal mines are at increased risk of exposure to toxic metals. Objectives: This study aimed to evaluate the correlation between soil contamination levels in areas around abandoned metal mine and the blood lead levels of local residents. Moreover, we assess the possibility of using soil contamination levels as a predictive indicator for human exposure level. Methods: Data from the Survey of Residents around Abandoned Metal Mines (2013~2017, n=4,421) and Investigation of Soil Pollution in Abandoned Metal Mines (2000~2011) were used. A random coefficient model was conducted for estimation of the lower level (micro data) of the local resident unit and the upper level (macro data) of the abandoned metal mine unit. Through a fitted model, the variation of blood lead levels among abandoned metal mines was confirmed and the effect of the operationally defined soil contamination level was estimated. Results: Among the total variation in blood lead levels, the variation between abandoned mines was 18.6%, and the variation determined by the upper-level factors such as soil contamination and water contamination was 8.1%, which was statistically significant respectively. There was also a statistically significant difference in the least square mean of blood lead concentration according to the level of soil contamination (p=0.047, low: 2.32 ㎍/dL, middle: 2.38 ㎍/dL, high: 2.59 ㎍/dL). Conclusions: The blood lead concentration of residents living near abandoned metal mines was significantly correlated with the level of soil contamination. Therefore, in biomonitoring for vulnerable areas, operationally defined soil contamination can be used as a predictor for human exposure level to hazardous substances and discrimination of high-risk abandoned metal mines.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.3
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• pp.347-352
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• 2010

There is a lack of survey standard for cross-to-nature small stream. In this research, we analyzed cross sectional survey data of Sanggachun stream, calculated variant quantity of soil, and suggested a survey interval. Descriptive analysis of cross sectional survey data shows the trend of stabilization; mean interval of survey is 14.91m(min: 7.0m, max: 39m), mean cross sectional variances are $0.82m^2$(min: $-3.80m^2$, max: $8.11m^2$) in 2004, $0.24m^2$ (min: $-5.25m^2$, max: $8.55m^2$) in 2005. Calculating results of variance quantity based on data of 65 cross sections show similar trends in 15m, 30m, 45m, 60m but different with results of 75m, 90m with Post-Hoc Test in statistical verification. We suggested standard cross sectional survey length of cross section for natural style small stream as 50m based on fitting results of standard variation of erosion and cumulation quantity by survey interval.

• Journal of Food Hygiene and Safety
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• v.31 no.6
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• pp.414-419
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• 2016

The aims of this study were to investigate microbial contamination levels and to survey sanitation management between Good Agricultural Practices (GAP) and non-GAP farms of lettuce and cucumber. The samples (lettuce, cucumber, soil, agricultural water, gloves, and packing plastic bag) were tested to analyze sanitary indicator bacteria (total aerobic bacteria, coliforms and Escherichia coli) and major pathogenic bacteria (Staphylococcus aureus, Bacillus cereus). In the lettuce farms, the contamination levels of total aerobic bacteria and coliforms in GAP farms were little lower than non-GAP farms or similar. Staphylococcus aureus and Bacillus cereus in soil and agricultural water of GAP farms were detected at higher levels than non-GAP farms in soil and agricultural water. In the case of cucumber farms, levels of total bacteria and Bacillus cereus in soil and total bacteria and coliform in gloves of GAP farms were higher than those of non-GAP farms, and other bacteria contamination levels in collected samples were similar. These results indicate that agricultural products produced from GAP farm still exhibited potential microbial risks. According to the field survey, a sanitation management in GAP farms was insufficient. These results could be useful as basic data to suggestion of plan for preventing microbial contamination and to improvement of GAP certification.

• Journal of Korea Soil Environment Society
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• v.1 no.1
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• pp.29-38
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• 1996

Among many geophysical prospecting methods, GPR(Ground Penetration Radar) and electrical resistivity method have been applied to a open waste dumping landfill for measuring of the site area and depth. The surveying was limited to a boarder of the site and inside area because of the field situation. The data of GPR were recorded by 50MHz antenna, and dipole array was used for electrical resistivity survey in the same survey line for the integrated interpretation. The result of GPR clearly indicated the horizontal boarder of site. However, the data of GPR did not have enough to measure the depth of site clearly. The electrical resistivity method may show the effective information by integrated interpreation. These results coincided with results of the boring test. Therefore, a combination of GPR and electrical resistivity is a good method for surveying of suspective open waste dumping landfill area and it's depth.