• Environmental Engineering Research
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• 제23권4호
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• pp.354-363
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• 2018

We examined the levels of brominated flame-retardants (BFRs) including polybrominateddiphenyl ethers (PBDEs), tetrabromobisphenol-A (TBBPA), hexabromocyclododecane (HBCD), and phthalates in indoor dusts in residential houses in Korea, and their distribution patterns depending on building characteristics. Mean concentrations of phthalate esters ($1,825{\mu}g\;g^{-1}$) were significantly higher than that of BFRs (PBDE: $1,332ng\;g^{-1}$, HBCDs: $459ng\;g^{-1}$, and TBBPA: $213ng\;g^{-1}$), indicating more frequent use of phthalate-containing products such as PVC flooring in the Korean houses. PVC flooring house was associated with higher concentrations of DEHP (p = 0.001) and BBP (p = 0.012), indicating that exposure to phthalate was higher in the PVC flooring house. Building age was significantly related with levels of PBDEs especially BDE-47 (p = 0.062), BDE-203 (p = 0.007), DEHP (p = 0.004), and BBP (p = 0.070), respectively, indicating that older buildings can produce higher amounts of PBDEs and phthalates. Our study can provide important information on the sources of BFRs and phthalates in residential houses in Korea.

• 한국환경과학회지
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• 제24권5호
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• pp.699-708
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• 2015

This study was performed to identify the state of the exposure and characteristics of pollutants by each process at 4 casting sites located in Gyeongsang-do from April to November 2013. The concentrations of methanol, crystallized silica glass, formaldehyde and phenol were analyzed by different process - casting process, molding process, core process, and shakeout & finishing process. The highest concentration of methanol was found in casting and molding process, whereas the highest concentration of crystalline quartz(Silica) was observed in core process. The most oxidized steel dusts and the highest concentration of fume were found in shakeout & finishing process. As a result of this study, those labors working at the casting site were found to be constantly exposed to various forms of hazardous chemicals; therefore, it is considered that this is the time to manage and plan how to reduce them. In addition, it is required to thoroughly manage the local exhauster, and improve the process and working environment to reduce various forms of hazardous chemicals.

• 대한안전경영과학회지
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• 제15권3호
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• pp.1-6
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• 2013

This study was conducted to compare the value of the working environment measurement with the expected exposure value drawn by using a program, thereby going to investigate whether it is available to the risk assessment of domestic workplace. We used the ECETOC TRA program which is one of the exposure predictive models. Four kinds of substances were measured in two workplace which was exposed to organic solvents and one kind of substance was measured in three workplace which was exposed to dusts and then an exposure assessment of chemical risk factors was conducted. The result value of the working environment measurement, solid substance exceeded standard in one site, and it was found that the other solid and liquid substances were within the standard. The value of the exposure assessment program showd the same result; it was higher than the value of the working environment measurement, suggesting that due to its nature, the exposure assessment program is run only on the worst situation. Therefore, it was found that when the exposure assesment program is used, variables should be substituted only after accurately assessing the workplace and it is a good idea to assess the risk beforehand with the exposure assessment program in the case of the workplace which employs no more than 5 people and where it is hard to assess the working environment.

• 한국환경보건학회지
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• 제43권1호
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• pp.71-76
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• 2017

Objectives: This study aimed to assess the environmental factors that affect particulate matters (PM10) and to compare with outdoor PM10 concentrations in an underground subway stations. Methods: The PM10 level was determined from May 2013 to September 2013 in the Seoul subway stations in four lines. PM mini-vol portable sampler sampler was used to collect PM10 for 6 hrs. Arithmetic means of PM10 concentrations with standard deviation (SD) were calculated. Paired t-test was used to compare the differences between indoor PM10 and outdoor PM10 concentrations with correlation analysis which was used to identify the association between indoor PM10 concentrations and environmental factors. Results: There were no different PM10 concentrations significantly between line 1, 2, 3 and 4 in an underground subway stations. Passenger number was positively associated with PM10 concentration while construction year was negatively associated with PM10 concentrations. Indoor PM10 concentrations were significantly higher than those in outdoor PM10 concentrations. PM10 concentrations were higher in the stations which were constructed before 1990s rather than the stations constructed after 1990s. Conclusion: PM10 levels in the underground subway stations varied greatly depending on the construction year. Therefore, it might need to be more careful management to the stations which constructed in before 1990s.

• Journal of Ecology and Environment
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• 제34권2호
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• pp.149-156
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• 2011

Phenological variables derived from remote sensing are useful in determining the seasonal cycles of ecosystems in a changing climate. Satellite remote sensing imagery is useful for the spatial continuous monitoring of vegetation phenology across broad regions; however, its applications are substantially constrained by atmospheric disturbances such as clouds, dusts, and aerosols. By way of contrast, a tower-based ground remote sensing approach at the canopy level can provide continuous information on canopy phenology at finer spatial and temporal scales, regardless of atmospheric conditions. In this study, a tower-based ground remote sensing system, called the "Phenological Eyes Network (PEN)", which was installed at the Gwangneung Deciduous KoFlux (GDK) flux tower site in Korea was introduced, and daily phenological progressions at the canopy level were assessed using ratios of red, green, and blue (RGB) spectral reflectances obtained by the PEN system. The PEN system at the GDK site consists of an automatic-capturing digital fisheye camera and a hemi-spherical spectroradiometer, and monitors stand canopy phenology on an hourly basis. RGB data analyses conducted between late March and early December in 2009 revealed that the 2G_RB (i.e., 2G - R - B) index was lower than the G/R (i.e., G divided by R) index during the off-growing season, owing to the effects of surface reflectance, including soil and snow effects. The results of comparisons between the daily PEN-obtained RGB ratios and daily moderate-resolution imaging spectroradiometer (MODIS)-driven vegetation indices demonstrate that ground remote sensing data, including the PEN data, can help to improve cloud-contaminated satellite remote sensing imagery.

• 한국대기환경학회지
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• 제28권3호
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• pp.282-293
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• 2012

This study aimed to show the chemical characteristics of $PM_{10}$ and $PM_{2.5}$ during Asian dust (AD) events and high PM episodes observed in Seoul. Time-resolved chemical composition of $PM_{10}$ or $PM_{2.5}$ was monitored in 1 hour interval using ambient ion monitor, semi-continuous carbon monitor, and on-line XRF spectrometer at Seoul intensive monitoring site in 2009. Considering that AD events were classified into three different cases according to the source area and pathway, the concentrations of ammonium-sulfate and trace metal components were relatively high when the AD were occurred in Gobi and inner-mongolia and transported across the Bohai bay. In addition, the influence of alkaline dust, which carried from saline land located in the northeastern China, was observed when the AD was originated from Gobi, inner-mongolia, and Manchuria. Except AD events, the high PM episodes observed in Seoul were impacted by various anthropogenic sources such as biomass burning, motor vehicle, oil combustion and road dust.

• 한국대기환경학회지
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• 제22권1호
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• pp.35-41
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• 2006

The steel foundries with electric arc furnaces handling metal scraps have recently gained an attention as a potential source of dusts. The present study focuses on the analysis of dust emissions and removals during furnace charging and melting processes by commercial CFD software named FLUENT. A body fitted grid system consisting of 880,000 meshes was first generated by Gambit for the electric arc furnace with the capacity of 60 ton/cycle and then FLUENT was invoked to solve the corresponding NavierStokers equation for the momentum, temperature and dust concentration. The entire processes from metal charging to metal melting were simulated to investigate the unsteady behaviors of fluid flows and dust concentrations. The model simulation results showed that as the top of the electric arc furnace opened for metal charging, hot plumes bursted out from the furnace rose strongly by buoyance and escaped mostly through the main hood. Therefore, the capacity of main hoods determined the vent efficiency in the metal charging process. As the furnace was closed after the metal charging and the metal melting processes was followed, the hot flow stream stretching from the furnace to the main hood was dissipated fast and the flow from the inlet of the bottom of the left hand side to the main and monitoring hoods constituted the main stream. And there was only a slow flow in the right hand side of the furnace. Therefore, the dust concentrations were calculated higher in the left hand side of the furnace, which was consistent with observations.

• 식물병연구
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• 제21권1호
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• pp.40-43
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• 2015

콩에 발생하는 불마름병은 주로 엽맥을 따라 병징이 형성되며, 이러한 병징의 형성에 대한 원인을 밝히고자 광학현미경 및 주사전자현미경으로 표면을 관찰하였다. 광학현미경 관찰에 의한 조직의 차이는 볼 수 없었으나 주사전자현미경으로 표면 관찰시, 잎 뒷면 미세한 엽모가 잎표면에 존재하였으며 엽맥 주위로는 엽모가 관찰되지 않았다. 세균은 엽맥 주위 엽모가 없는 부분에 주로 부착되어 있었고, 엽모가 있는 부분에서 세균은 관찰되지 않았다. 또한 잎에 불마름병균을 접종 후 표면 미생물을 배양시 엽맥주위에서 주로 세균이 검출되어 엽모의 존재가 불마름병균의 부착을 방해하여 엽맥주변으로 병징이 발현된 것으로 판단된다.

• 한국대기환경학회지
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• 제5권1호
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• pp.68-78
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• 1989

The heavy metal of suspended particulates with human health has long been studied in environmental interest concerned. This study was intended to identify harmful heavy metals of the ambient air borne dusts which were related with the respirable sizes in the aerodynamics. Two sampling sites were selected comparatively; one was in the Shinchon area, which is the commercial district with heavy traffic and the other site was in the Bulgwang area which is residential area. The supended particulates were sampled by high volume air sample with 6 cascade impactor stages. The heavy metals in terms of As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, V and Zn were determined by stomic absorption spectrometry or inductively coupled plasma emission spectrometry. The samples weretaken bimothly for seven consecutive days from May 1987 to March 1988. The annual average concentration of the respirable suspended dust of which diameter is less than 10$\mum$ was 152.59 $\mug/m^3$ of the Shinchon air samples; the respirable dust was equivalent to approximately 85% of the total suspended particulates. The annual average concentration of the respirable suspended dust of the Bulgwang air samples was 112.56 $\mug/m^3$; that was approximately 86% of the total suspended particulates. The concentration of heavy metals was investigated in relation to the particle size. The concentration of Cr, Fe, Mn and V were tended to be much more in the coarse particles than in the fine particles. Cd and Pb in the fine particles were more than in the coarse particles. In the partial correlation coefficients; in the Shinchon area, high correlations among Fe, Se and Mn were determined; it is assumed that those sources would be originated from coal, gasolineand diesel. In Bulgwang area, would be high correlation among Fe, Se, Hg and Mn considered to be originated from coal, Bunker-C and heavy oil as well. From the above results, the hazardous heavy merals in air should be measured and controlled in originally their sources.

• 화약ㆍ발파
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• 제30권1호
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• pp.17-28
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• 2012

도심지에서의 구조물 해체공사는 소음, 진동 및 분진을 발생시켜 주변에 불편을 끼치는 경우가 많아 다양한 제어방안이 고안되어 사용되고 있다. 그 중에서 화약을 이용해 순간적으로 구조물을 붕괴, 전도시키는 발파해체공법은 시공 중 먼지, 소음 등으로 주변피해를 최소화시키고, 공사기간을 단축해 공사비도 절감되며, 작업자에 대한 안전의 확보가 가능한 친환경적인 공법으로 시공사례가 증가하고 있다. 한편, 도심지에 위치한 구 성남시청 구조물은 기둥과 보로 이루어진 철근콘크리트 라멘구조로 여러 개의 높이가 다른 건물들이 연결통로를 통해 서로 이어져 있는 복합구조물로써 공기단축과 주변 주민에 대한 피해를 최소화하고자 발파해체공법을 적용하여 시공하였다.