• Journal of Advanced Marine Engineering and Technology
• /
• 제35권8호
• /
• pp.1124-1131
• /
• 2011

본 연구는 기계식 환기장치에 의한 선박 선실 내의 환경오염물질 확산특성을 파악한 것으로, 연구성과는 다음과 같다. 오염발생 선실 내에서는 오염발생 35분 경과 후 오염물질이 대부분 제거되었고, 신선외기 도입율 변화에 따른 영향은 무시할 수 있었다. 오염원 선실에 인접한 선실의 오염물질 제거시간은 65분~100분 정도로 신선외기 도입율에 따라 차이가 발생했다. 상부 데크에 오염원 선실이 있는 경우가 하부 데크에 오염원 선실이 있는 경우에 비해, 오염농도는 10배 정도 높지만, 대표 공간 중 오염된 공간의 수는 오히려 1/2에 불과했다. 그러나 전체공간을 대상으로 한 평가에서는, 상부 데크에서 오염물질이 발생한 경우에는 Upper 데크 이상 상부 데크 내 공간의 50% 이상이 평가기준 0.001%, 0.01%, 0.1% 일 때 오염될 것으로 예측되었고, 하부 데크에서 오염물질이 발생하는 경우에는 하부 데크를 중심으로 오염공간이 많지만 오염판단기준 0.01%일 때에는 Shelter 데크 이상의 상부 데크에서도 오염선실이 나타났다. 한편, 신선외기 도입량 변화에 따른 오염농도 및 오염공간 비율을 분석한 결과 설계용량 대비 75% 이상의 외기가 도입될 때 선실 내 오염수준이 낮아지는 것으로 평가되었다.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제29권3호
• /
• pp.14-22
• /
• 2024

This study established risk-based fluoride soil contamination standards according to the Korean Soil Contaminant Risk Assessment Guidelines (SRAG). Ten exposure scenarios were evaluated, broadly categorized into Scenario 1, which used the default parameters from the current SRAG, and Scenario 2, which used the latest exposure factors and bio-concentration factors. Fluoride soil standards corresponding to a total hazard index (HI) of 1.0 were determined for each scenario. For children in agricultural areas, the derived risk-based soil fluoride standard was 70 mg/kg for Scenario 1 and 27 mg/kg for Scenario 2. In industrial areas, the risk-based fluoride soil standard was 2200 mg/kg in Scenario 1 and 2300 mg/kg in Scenario 2. This study clearly demonstrated that the crop ingestion exposure pathway exerted predominent influence on the estimated human health risk standards. Additionally, using the Added Risk Approach and considering soil background concentrations, the total fluoride soil standards for residential areas ranged from 232 mg/kg to 444 mg/kg, while the standards for industrial areas ranged from 2405 mg/kg to 2674 mg/kg.

• 한국환경보건학회지
• /
• 제32권2호
• /
• pp.186-191
• /
• 2006

Metal contamination of medicinal herbs is of growing concern because of their potential adverse health effects. In this study, metal exposures were estimated and their potential health risks were preliminarily evaluated using available data including metal contamination levels and consumption estimates of herbal medicine in Korea. Consumption and contamination data of 34 medicinal herbs abundantly used in Oriental medicine in Korea were used in this study. Lead, mercury, arsenic, cadmium, cobalt, and chrome were identified as contaminants of potential health concerns. Even based on a conservative exposure scenario, i.e., consuming 5 times more herbal medicine with 95th percentile contamination levels, health risks associated with herbal medicine consumption were estimated to be minuscule. Herbal consumption was 0.3% of the provisional tolerable daily intake levels recommended by Joint Expert Committee on Food Additives (JECFA) of WHO/FAO. However, it should be noted that there are several important assumptions and uncertainties associated with this evaluation: This study was conducted for only 34 types of medicinal herbs of which consumption and metal contamination data were available. In addition, there are no reliable herbal medicine consumption data among Korean population. The pattern and amount of herbal (medicine) consumption in Korea need to be investigated in order to conduct more refined risk assessment associated with metal contamination in medicinal herbs.

• 한국시스템다이내믹스연구
• /
• 제6권1호
• /
• pp.125-145
• /
• 2005

The Sihwaho Project got off to a bad start, which led to a series of mishaps and an imbalance of the whole project. The purpose of this study is to select the case of Sihwaho as a research subject, clean up the contamination caused by the ill planned project, develop suitable measures to stabilize the lake environment, and find the implications of similar development projects. For this, the authorshave conducted three simulations after studying the structural reasons for the failure of the Sihwaho Policy by identifying cause and effect relationships, pre-testing a number of policy measures for the current lake project, and presenting measures for solving the contamination problem at the lake. The simulations have shown us that filling the lake with seawater is inadequate to solve the problem and that we also have to make efforts to reduce the volume of wastes to the lake as well. The authorshave also analyzed the degree of difference between the simulation and survey results for scenario 1, in which we have studied how much seawater can reduce the contamination of the Sihwaho Lake without the effort to reduce the volume of wastes into the lake. The survey showed that most citizens and employees of the Ministry of Environment did not think it would be serious as the simulation results pointed out, and the employees of the Ministry of Environment were more optimistic about the situation than the public.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제23권1호
• /
• pp.54-62
• /
• 2018

This paper is aimed at source tracking of soil heavy metal contamination at a site established by reusing construction wastes. The soil heavy metal concentration at the study site peaked at a depth range of 5-10 m. Column studies were conducted to investigate the possibility of the contamination scenario of infiltration of stormwater carrying heavy metals of ground origin followed by selective heavy metal accumulation at the 5-10 m depth range. Almost all amount of lead, zinc, cadmium, and nickel introduced to the columns each packed with 0-5 m or 5-10 m field soil were accumulated in the column. The very poor heavy metal mobility in spite of the weak association of the heavy metals with the soil (characterized by a sequential extraction procedure) can be attributed to the high pH (10-11) of the construction wastes. From the results, the heavy metal contamination of the subsurface soil by an external heavy metal source was determined to be very unlikely at the study site. The column study applied in the current study is expected to be a useful methodology to present direct evidence of the contaminant source tracking at soil contamination sites.

• Journal of Radiation Protection and Research
• /
• 제40권4호
• /
• pp.231-243
• /
• 2015

Four different paddy soils collected around the Gyeongju nuclear site were treated with $^{99}TcO_4{^-}$ solution under the assumption of two contrasting contamination scenarios. Scenario I (SN-I) is for a pre-transplanting deposition of $^{99}Tc$ followed by plowing, whereas SN-II is for its deposition onto the water surface shortly after transplanting. Rice plants were grown in lysimeters in a greenhouse. Plant uptake of $^{99}Tc$ was quantified with the $TF_{area}$ ($m^2{\cdot}kg^{-1}-dry$). The SN-II $TF_{area}$ values for straws and brown rice, having been generally higher than the SN-I values, were within the ranges of $6.9{\times}10^{-3}{\sim}4.1{\times}10^{-2}$ and $5.2{\times}10^{-6}{\sim}7.3{\times}10^{-5}$, respectively. Sorption onto clay seems to have decreased $^{99}Tc$ uptake in SN-I, whereas it may have had an insignificant effect in SN-II. A phenomenon characteristic of submerged paddy soil, i.e., the development of a thin oxic surface layer may have greatly affected the rice uptake of SN-II $^{99}Tc$. The surface-water concentrations of $^{99}Tc$ were much higher in SN-II than in SN-I. For the percolating water, however, the opposite was generally true. At most 1.3% of the applied $^{99}Tc$ were leached through such percolation. The use of empirical deposition time-dependent $TF_{area}$ values was considered desirable in assessing the radiological impact of a growing-season deposition of $^{99}Tc$ onto paddy fields.

• 천문학회보
• /
• 제38권2호
• /
• pp.78.1-78.1
• /
• 2013

The hierarchical model of galaxy formation predicts that galaxy halos contain merger relics in the form of long stellar stream. Thus, tidal substructure of stars around globular clusters, such as tidal tails, could be an essential evidence of the merging scenario in the formation of the Galaxy. From April 2010 to December 2012, we obtained $45^{\prime}{\times}45^{\prime}$ wide-field JHKs near-infrared photometric imaging data for about 20 globular clusters in the Milky Way, and examined the stellar density distribution around globular clusters. Here, we introduce the preliminary results of stellar spatial distributions and radial surface density profiles of four globular clusters. In order to minimize the field star contamination and identify the cluster's member candidates stars, we used a statistical filtering algorithm and gave weights on the CMDs of globular clusters. In two-dimensional stellar density maps, we could found tidal stripping structures for some globular clusters. The orientation of tidal substructure seems to associate with the effects of dynamical interactions with the Galaxy and cluster's orbit. Indeed, the radial surface density profile accurately describes this stripping structures as a break in the slope of profile. The observational results could give us further observational evidence of merging scenario of the formation of the Galaxy.

• Journal of Radiation Protection and Research
• /
• 제35권1호
• /
• pp.6-11
• /
• 2010

Embodying the safety of radioactive waste disposal requires the relevant safety criteria and the corresponding stylized methods to demonstrate its compliance with the criteria. This paper proposes a conceptual model of risk-based safety evaluation for integrating complex potential radiation exposure situations in radioactive waste disposal. For demonstrating compliance with a risk constraint, the approach deals with important exposure scenarios from the viewpoint of the receptor to estimate the resulting risk. For respective exposure situations, it considers the occurrence probabilities of the relevant exposure scenarios as their probability of giving rise to doses to estimate the total risk to a representative person by aggregating the respective risks. In this model, an exposure scenario is simply constructed with three components:radionuclide release, radionuclide migration and environment contamination, and interaction between the contaminated media and the receptor. A set of exposure scenarios and the representative person are established from reasonable combinations of the components, based on a balance of their occurrence probabilities and the consequences. In addition, the probability of an exposure scenario is estimated on the assumption that the initiating external factors influence release mechanisms and transport pathways, and its effect on the interaction between the environment and the receptor may be covered in terms of the representative person. This integrated approach enables a systematic risk assessment for complex exposure situations of radioactive waste disposal and facilitates the evaluation of compliance with risk constraints.

• Journal of Microbiology and Biotechnology
• /
• 제20권2호
• /
• pp.229-237
• /
• 2010

Recently, many cases related to viral gastroenteritis outbreaks have been reported all over the world. Noroviruses are found to be leading as the major cause of outbreaks of acute gastroenteritis. Patients with acute gastroenteritis are normally found to be positive with norovirus when the stools and vomit are analyzed. This paper reviews various activities and previous reports that describe norovirus contamination in various food matrixes and the relationship between food handlers. Lately, a numbers of norovirus outbreaks have been reported that are involved with fresh produce (such as vegetables, fruits), shellfish, and prepared food. Food produce processed by infected food handlers may therefore become easily contaminated. In addition, foods that required much handling and had been eaten without heat treatment gave the high risk for getting foodborne illnesses. The standard method for detection of norovirus has already been available for stool samples. However, only a few methods for detection of norovirus in food samples have been developed until now.

• 지질공학
• /
• 제32권4호
• /
• pp.437-448
• /
• 2022

위해성 평가란 위험 물질에 대해 인체 건강에 대한 위협을 계산하는 것으로 발암성 평가와 비발암성 평가로 나뉜다. 본 연구는 경남 한 농촌 지역의 비소 오염 지하수를 생활용수, 음용수로 사용할 경우 인체에 미치는 영향을 평가하였다. 연구를 위해 국가지하수정보센터의 지하수 수질 자료를 이용하였다. 자료에 따르면 연구지역인 농촌 지역의 지하수는 평균 비소 농도가 16.27 ㎍/L로 세계보건기구가 제시한 비소 농도(10 ㎍/L)보다 높게 나타난다. 이에 따라 건강 위해가 있을 것이라고 판단하여 미국환경청에서 제시한 방법을 이용하여 위해성 평가를 수행하였다. 세 가지 노출 시나리오(생활용으로 이용하는 시나리오 1과 음용으로 이용하지만 사용량이 다른 시나리오 2와 3)를 작성하여 비소 노출에 대한 경우를 통해 위해성을 계산하였다. 시나리오 1에서의 HQ의 중앙값은 0.77, CR의 중앙값은 0.013을 보이며 시나리오 2에서는 HQ의 중앙값은 0.08, CR의 중앙값은 3.69 × 10^-5로 나타났다. 시나리오 3은 HQ의 중앙값은 0.11, CR은 4.82 × 10^-5였다. 인체에 잠재적 위험성이 가장 높게 나타난 것은 시나리오 1로 나타났다. 지하수 내의 비소 기원을 자세히 밝힐 필요가 있으며 지하수 이용 시 정화할 수 있는 대책 마련이 필요하다.