• 한국수산과학회지
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• 제36권3호
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• pp.225-229
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• 2003

Plant ash and soil drainage, derived by frequent mountain fires during winter, might cause biological contamination to seaweeds at seashore and river mouse area. To thalli of Ulva pertusa, maximum non-lethal concentration(MNLC), lethal concentration 50 $(LC_{50})$ and minimum lethal concentration (MLC) of pine needle ash were shown as 60, 350 and 550 mg/mL, respectively. The yellow loess and granite sand did not damage at concentrations of 20 and 200 mg/mL, respectively To thalli of Porphyra yezoensis, the MNLC, LC5O, MLC of pine needle ash were shown as 0.08, 0.4 and 1.0 mg/mL, respectively. Effects of yellow loess and granite sand were approximately 1/2 and 1/10 of the ash. To thalli of Undaria pinnatifida, the pine needle ash, yellow loess and granite sand did not damage at the concentration range of 20 to 40 mg/mL. Change of pigments $(chlorophyll\;\alpha,\;lutein,\;\beta-carotene,\;phycoerthrin)$ was also determined at the MNLC, $LC-{50}$ and MLC of pine needle ash. Among three seaweeds tested, P. yezoensis produced the most 2.7-fold of lutein and 2.3-fold of $\beta-carotene$ at $LC-{50}$ of the ash. Thus the P. yezoensis, appeared as a sensitive indicator, could be used as one of test organisms for determination of the biological effect of pollutants contaminated in marine environment.

• 한국지하수토양환경학회지:지하수토양환경
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• 제17권6호
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• pp.69-81
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• 2012

Diverse geostatistical tools such as kriging have been used to estimate the volume and spatial coverage of contaminated soil needed for remediation. However, many approaches frequently yield estimation errors, due to inherent geostatistical uncertainties. Such errors may yield over- or under-estimation of the amounts of polluted soils, which cause an over-estimation of remediation cost as well as an incomplete clean-up of a contaminated land. Therefore, it is very important to use a better estimation tool considering uncertainties arising from incomplete field investigation (i.e., contamination survey) and mathematical spatial estimation. In the current work, as better estimation tools we propose stochastic simulation approaches which allow the remediation volume to be assessed more accurately along with uncertainty estimation. To test the efficiency of proposed methods, heavy metals (esp., Pb) contaminated soil of a shooting range area was selected. In addition, we suggest a quantitative method to delineate the confident interval of estimated volume (and spatial extent) of polluted soil based on the spatial aspect of uncertainty. The methods proposed in this work can improve a better decision making on soil remediation.

• Nuclear Engineering and Technology
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• 제54권8호
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• pp.2792-2800
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• 2022

In the core of the WWR-K reactor, a long-term irradiation of tristructural isotopic (TRISO)-coated fuel particles (CFPs) with a UO₂ kernel was carried out under high-temperature gas-cooled reactor (HTGR)-like operating conditions. The temperature of this TRISO fuel during irradiation varied in the range of 950-1100 ℃. A fission per initial metal atom (FIMA) of uranium burnup of 9.9% was reached. The release of gaseous fission products was measured in-pile. The release-to-birth ratio (R/B) for the fission product isotopes was calculated. Aspects of fuel safety while achieving deep fuel burnup are important and relevant, including maintaining the integrity of the fuel coatings. The main mechanisms of fuel failure are kernel migration, silicon carbide corrosion by palladium, and gas pressure increase inside the CFP. The formation of gaseous fission products and carbon monoxide leads to an increase in the internal pressure in the CFP, which is a dominant failure mechanism of the coatings under this level of burnup. Irradiated fuel compacts were subjected to electric dissociation to isolate the CFPs from the fuel compacts. In addition, nondestructive methods, such as X-ray radiography and gamma spectrometry, were used. The predicted R/B ratio was evaluated using the fission gas release model developed in the high-temperature test reactor (HTTR) project. In the model, both the through-coatings of failed CFPs and as-fabricated uranium contamination were assumed to be sources of the fission gas. The obtained R/B ratio for gaseous fission products allows the finalization and validation of the model for the release of fission products from the CFPs and fuel compacts. The success of the integrity of TRISO fuel irradiated at approximately 9.9% FIMA was demonstrated. A low fuel failure fraction and R/B ratios indicated good performance and reliability of the studied TRISO fuel.

• 한국식생활문화학회지
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• 제9권3호
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• pp.289-301
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• 1994

The purpose of this study was to investigate housewives' perception, interest and consumption of organic food, and to identify the variables influencing on them. The sample was selected from 411 housewives living in Seoul from 1st of September to 20th of September in 1993. Used statistical methods were frequency, percentage, mean, Cronbach's ${\alpha}$, factor analys, ANOVA, Duncan's multiple range test, t-test, correlation, regression analysis and Path analysis. The major results are as follows: 1) Housewives' perception degree of organic food in its variety, easy availability and contribution to health was relatively high level, but price level, reliability and packing condition was somewhat low level. Out of housewives' many images of organic food, taste health care, quality and necessity factors can be implicated. 2) Housewives' interest degree of organic food is somewhat high level 3) Housewives' consumption degree of organic food was relatively low level and was affected by their perception of oraganic food. 4) Frequency to use seasonings was the major independent variable which influenced to housewives' perception degree of organic food, while recognition on enviornmental contamination was the major independent variable which influenced to their interest degree of organic food, and their total perception on organic food was the major independent variable which influenced to their consumption degree of oragnic food. Therefore, it is considered that their total perception to it can decide the demand of organic food 5) Housewives' perception and interest degree of it was the major intervening variable which influenced to their consumption degree of oragnic food.

• 지질공학
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• 제29권2호
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• pp.113-122
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• 2019

본 연구에서는 도로터널 건설시 감소하는 지하수위 저하의 범위와 이로 인한 인근 계곡 소하천의 영향을 평가하기 위한 유동해석 및 터널공사 시 오탁수 배출에 의한 인근 수원의 오염여부를 평가하기 위한 오염물 이동 해석을 수행하였다. 터널굴착 공기인 30개월 동안 하강하는 지하수의 저하량은 최대 27 m로 나타났고 터널중심에서 50 m 이내에서 가장 큰 것으로 확인되었다. 또한 이로 인한 지하수의 유동이 터널 내로 유입되는 형상으로 보여주고 있으며 터널반경 200 m까지는 적지만 수위저하의 영향이 나타났다. 터널에서 배출되는 오탁수 배출의 영향을 검토하기 위한 오염물 이동 수치모델링 결과 터널종단부에서 발생하는 탁수의 거동범위는 최대 120 m내외이며 이로 인한 소하천의 오염 위험은 크지 않을 것으로 평가되었다.

• Nuclear Engineering and Technology
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• 제55권8호
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• pp.2802-2811
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• 2023

In a first-of-its-kind study, terrestrial radionuclide concentrations were measured in 35 topsoil samples from the outskirts of Dhaka using HPGe gamma-ray spectrometry to assess the radiological consequences of such a vast number of brick kilns on the plant workers, general as well as dwelling environment. The range of activity concentrations of ²²⁶Ra, ²³²Th, and ⁴⁰K is found at 19 ± 3.04 to 38 ± 4.94, 39 ± 5.85 to 57 ± 7.41, and (430 ± 51.60 to 570 ± 68.40) Bq/kg, respectively. ²³²Th and ⁴⁰K concentrations were higher than the global averages. Bottom ash deposition in lowlands, fly ash buildup in soils, and the fallout of micro-particles are all probable causes of the elevated radioactivity levels. ¹³⁷Cs was found in the sample, which indicates the migration of ¹³⁷Cs from nuclear accidents or nuclear fallout, or the contamination of feed coal. Although the effective dose received by the general public was below the recommended dose limit but, most estimates of hazard parameters surpass their respective population weighted global averages, indicating that brick kiln workers and nearby residents are not safe due to prolonged exposures to terrestrial radiation. In addition, the soil around sampling sites is found to be unsuitable for agricultural purposes.

• 한국환경보건학회지
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• 제35권4호
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• pp.334-342
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• 2009

Perfluorinated compounds (PFCs) have a wide range of domestic and industrial applications, but they are persistent in the environment. Perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS) are among the metabolites of PFCs and occur at high concentration in the environment. Korea is the largest importer of PFC compounds in the world, therefore, the accumulation of these compounds is possible. In this study, the concentrations of PFOS and PFOA were determined in water samples taken from sewage treatment plants (STPs) and the Han River in Seoul, Korea. After extraction with a HLB cartridge, PFCs in the samples were analyzed by HPLC with an ion trap mass spectrometry in electrospray negative mode. Limits of detection was between 1 and 1.6 ng/l. The result showed that the concentrations of PFOS and PFOA in effluent and influent of the four STPs in Seoul were 60~570 ng/l, and not detected (nd)~254 ng/l, respectively. The levels of PFOS and PFOA were higher in the effluents which passed through the treatment process than in influent water samples which was against expectation. The concentration of PFOA and PFOS in the Han River was 60~570 ng/l and nd~254 ng/l, respectively. PFOA was detected in every sample, but PFOS was only detected in the downstreams of the Han River. This result indicates that there is comprehensive contamination of PFCs in the aquatic environment in Korea.

• 한국수산과학회지
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• 제46권5호
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• pp.626-637
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• 2013

We measured the grain size, ignition loss (IL), chemical oxygen demand (COD), acid volatile sulfide (AVS) and trace metals (Al, Fe, Cu, Pb, Zn, Cd, Cr, Mn, Hg, and As) of intertidal surface sediment collected from 11 islands (62 stations) in the southern region of Jeollanam Province. The objective of this research was to evaluate the organic matter and trace metals contaminations of sediments from coastal island tidal flats. Surface sediment texture was characterized as follows: mud, sandy silt, muddy sand, and slightly gravelly sand facies. The finer sediments are mainly dominated in the northern part of each island. The concentrations of IL, COD, AVS and some trace metals (Al, Fe, Zn, Cr, Cu, and Hg) were higher in the northwestern part of Wan Island and the area between Gogeum and Sinji Islands, and were associated with relatively finer sediment, as compared to other locations. The concentrations of Mn, Pb, Cd, and As were higher in the northwestern and southeastern parts of Geoguem and Pyungil Islands, but were not correlated with mean grain size. Based on sediment quality guidelines (SQGs), the concentrations of trace metals were lower than the values of effect range low (ERL), used in United States, and threshold effects level (TEL), used in Korea, with exception of As. Similarly, the intertidal sediments were moderately contaminated with As, based on the the enrichment factor (EF) and the geoaccumulation index ($I_{geo}$). The high concentration of As in intertidal sediments from this study region may be due to the input of naturally or artificially contaminated submarine groundwater, contaminated waste from seaweed aquaculture operations and/or land-based seaweed processing facilities. Further studies are needed to identify the sources of As in this study region, and to determine the effects of As contamination on coastal ecosystem.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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• pp.131-137
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• 2006

This study was investigated the contents of heavy metals in plants at Dalcheun mine area, in order to offer basic data for phytoremedation on soil contamination by heavy metals. As the results of this study, the contents of Ni, As, Cd in plants were the highest at the west area of Dalcheun mine area. But the content of Zn was similar in all of Dalcheun mine area. For the herbaceous plants, the contents of heavy metals were higher in plants which were included in Gramineae and Compositae than any other families. And then the contents of Ni, Zn, Cd in root were higher $1.4{\sim}1.8$ times than stem, especially the content of As was higher 4 times. For the trees, the contents of heavy metals were usually high in Zanthoxylum piperitum, Pine tree, Chestnut tree, Quercus acutissima and Lindera obtusiloba. The contents of heavy metals with parts of tree were almost same range. All experimental result, we paid attention on two conclusions. First, the contents of heavy metals in herbs was higher than in trees. And second, if there were some spices that the content of heavy metal in leave were higher than in root, they could accumulate that kind of heavy metal. Therefore, It is above 2 times which the content of heavy metal in the leave is higher than in the root about herbs, that kind of plants was regarded as a accumulation species. According as the heavy metals, accumulation species were selected. We think that the accumulation species are able to absorb the heavy metals from the soil, they will make use of phytoremedation on contaminated soil by heavy metals.

• 동아시아식생활학회지
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• 제23권2호
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• pp.153-170
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• 2013

This study examined awareness and information acquisition behavior regarding food hygiene and safety of university students to improve safe dietary practices and to get basic information to develop educational materials for food safety. It was conducted among 276 university students of Qingdao University and Liaocheng University in Shandong province, China through a self-administered questionnaire. Data were analyzed by SPSS Windows V.19.0. To describe characteristics of the respondents, frequency distributions were used. In addition, t test, one-way analysis of variance and Duncan's multiple range tests were conducted. The results were as follows: The respondents were generally interested in food hygiene and safety. However, the level of awareness regarding the food hygiene and safety system in China was not high. Almost forty-five percent of the respondents did not think that foods produced and distributed in China were safe. For the reasons for their distrust, most of the students replied that they did not trust the safety 'because of distrust for hygiene of the food process', followed by 'because of distrust for food distribution' and 'because of excess or illegal use of food additives on food process'. The respondents answered for the concern level toward food hygiene and safety foodborne disease threatened food safety the most, followed by heavy metal contamination and endocrine disruptors. The respondents acquired most information from electronic media including TV and radio. Most of the students wanted to participate in food hygiene and safety education. Finally, when they found hazardous or foreign materials in food the most frequent reaction was 'paying attention in the next purchase', followed by 'notifying others', and 'letting it go this time but never buying that product in the future'.