• 한국물환경학회지
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• 제20권5호
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• pp.494-499
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• 2004

Growth in population and urbanization has progressively increased the loadings of pollutants from non-point sources as well as point sources. Therefore, it is necessary to manage both point and non-point sources contaminations for protecting water environment and improving water quality. This study investigated the characteristics of pollutant release over a wide range of rainfall intensities as a requisite to control road runoff that accounts for the largest portion of non-point source contamination in urban areas. Samples of runoff rainwater collected from real road surfaces were analyzed for physicochemical parameters such as pH, suspended solids, and heavy metals. A experimental model road ($30cm{\times}30cm$) was also used to evaluate wash-off properties of pollutants deposited on the surface as functions of time and rainfall intensity. Analysis of runoff samples on rain events showed that the pollutant wash-off patterns for heavy metal and suspended solids were similar. This implies that the particles in rainwater adsorb heavy metals. Experiments using the model road made of impervious asphalt demonstrate a strong first flush phenomenon. At high rainfall intensity, approximately 80% of total pollutants were released within 15 min. The pollutant wash-off rates rapidly increase from 9 mm/hr to 12 mm/hr of rainfall intensity and decrease over 12 mm/hr of rainfall intensity.

• Food Science and Biotechnology
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• 제15권1호
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• pp.152-157
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• 2006

Enterobacter sakazakii, designated as an unique microbial species in 1980, may cause bacteremia, necrotizing enterocolitis and infant meningitis. The distribution and the thermostability of E. sakazakii in unprocessed ready-to-eat (RTE) agricultural products of 252 and in 25 powdered infant formulas (PIF) were analyzed. Eighty one, 50, 43, and 47% of brown rice, pumpkin, potato, and carrot samples, respectively, had aerobic plate counts (ARC) in the range of 5 log CFU/g or more. Almost all the other products sampled had APC of approximately 2 log CFU/g. Fifty three, 75, 67, and 68% of banana, pumpkin, soybean, and carrot had Enterobacteriaceae counts approximating 3 log CFU/g. Sixty six percent of the brown rice tested had Enterobacteriaceae counts approximating 5-6 log CFU/g. E. sakazakii was isolated from 3/25(12%), 4/23(17%), 1/24(4%), and 1/27(4%) of PIF, brown rice, laver, and tomato samples, respectively. D-values were 3.52-4.79 min at 60 and $D_{60}-values$ were similar as the isolates reported. Thermal inactivation of four thermovariant E. sakazakii strains during the rehydration of PIF with hot water were investigated. At $50^{\circ}C$, the levels of E. sakazakii decreased one log CFU/g for 4-6 min and thereafter the levels remained stable for 20 min. At $60^{\circ}C$, inactivation by about 2 log CFU/g occurred for 20 min. Therefore, the unprocessed agricultural products might be a source of contamination for PIF when used as an ingredient after drying and pulverization. Rehydration of PIF for infant feeding with a water temperature of $60^{\circ}C$ rather than $50^{\circ}C$, as recommended by the manufacturers, may be helpful in the reduction of potential E. sakazakii risk.

• Journal of Radiation Protection and Research
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• 제41권4호
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• pp.418-423
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• 2016

Background: This work was to get information about $^{90}Sr$ contamination of the environment by using soil and moss from selected areas in Jeju Island, Korea. Materials and Methods: The activities of $^{90}Sr$ in soil and moss samples were investigated at nine locations of Jeju island, Korea. The soil samples have been collected at 4 sites of Jeju island during June to August of 2013, analyzed for vertical distribution of $^{90}Sr$ activities. The moss samples have been collected at 5 sites of Jeju island during November of 2011 to June of 2012, and analyzed for radioactive $^{90}Sr$. Results and Discussion: The $^{90}Sr$ vertical concentrations in the investigated soil samples were 2.77 to $18.24Bq{\cdot}kg^{-1}$ in eastern part, 1.69 to $18.27Bq{\cdot}kg^{-1}$ in northern part, 3.76 to $13.46Bq{\cdot}kg^{-1}$ in the western part and 1.09 to $8.70Bq{\cdot}kg^{-1}$ in the southern part of the Mt. Halla in Jeju island, respectively. Activities of $^{90}Sr$ show the highest value at the surface soil and decrease with depth. The activity concentration measured was in the range of 79.6 to $363Bq{\cdot}kg^{-1}$ -dry moss. Conclusion: This material is expected to be basis reference for survey of environmental radioactivity in Jeju Island.

• 대한의생명과학회지
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• 제29권2호
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• pp.81-87
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• 2023

Pan-Enterovirus (Pan-EV) infects millions of children and infants worldwide every year. As severe infections have recently been reported, the need for monitoring has consequently intensified. Pan-EV is a categorical name for waterborne enteroviruses belonging to the Picornaviridae family, and includes a wide range of pathogens including Coxsackievirus (CoxV), Echovirus (EcoV) and Enterovirus (EV). In this study, we proposed an optimal RT-nested PCR method for diagnosis of various types of Pan-EV in an aquatic environment and developed a positive control. Considering detection sensitivity, specific reaction, and final identification, one condition capable of amplifying 478 bp among the four candidates in the 1^st round PCR (RT-PCR) and one condition in the 2^nd round PCR (nested PCR) were selected. Through the detection of nucleic acids extracted from 123 groundwater samples and the detection sensitivity test based on artificial spiking in the sample, the methods are optimal for non-disinfected water samples such as groundwater. We developed a positive control for Pan-EV detection that can be amplified to different sizes under the two conditions. Accuracy could be further improved by testing for contamination from the control group. The method proposed in this study and the positive control developed are expected to be used in monitoring Pan-EV in aquatic environments including groundwater through future research using more samples.

• 한국지반신소재학회논문집
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• 제23권1호
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• pp.1-7
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• 2024

본 연구에서는 지중 내 오염물질(TPH, Phenol)의 확산 방지를 위해 오염 발생시에만 선택적으로 차수성능을 발현하는 차수재를 제조하고자 하였다. 선택적차수재의 구성물질로는 주문진규사, 벤토나이트, 폴리올레핀 엘라스토머, 스필하운드 마린을 사용하였으며, 본 연구에서는 구성물질들의 활용가능성을 평가하기 위해 기초 특성 및 환경유해성을 확인하였으며 오염물질과의 접촉 24시간 후 변화되는 투수특성을 비교하여 차수재로서 사용가능성을 확인하였다. 각 구성물질의 pH는 일반 지하수 pH 범위와 유사하였으며 독성특성 및 유해물질 용출가능성 분석결과 기준치 이하의 함량을 보여 환경유해성은 없다고 판단되었다. 또한 오염물질 접촉 전‧후 투수계수를 비교하였을 때, 접촉 전 α × 10^-3cm/sec 내외의 투수계수가 오염물질과 접촉 이후 α × 10^-6cm/sec로 감소된 결과를 보여 차수재의 비오염 상황에서는 투수성과 오염발생시 차수성능 발현을 확인할 수 있었다.

• Journal of Preventive Medicine and Public Health
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• 제7권1호
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• pp.101-105
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• 1974

A study was carried out for the purpose of grasping the status of bacteriological contamination of the public wells in Iri city, during the period from 1 to 15 August, 1974. Coliform groups were detected by membrane filter method and physical conditions of the wells were checked. As results of this study, following conclusion were obtained. 1. The households which used the piped water occupied 70.8 per cent (11,907 households) out of total householdsir Iri city. 2. Temperature of the well water was 38 out of 50 samples (72.0%) with 12.1 to $16.0^{\circ}C$ and 9 wells with 10.1 to $12.0^{\circ}C$. 3. The pH values range of the well water was 6.0 to 7.9, 11 cases or 22,0 per cent less than 6.5 and 8 cases or 16.0 per cent more than 7.5. 4. The residual chlorine was found at 15 samples (30.0%) contained 0.1 to 0.5ppm, 9 samples (18.0%), 0.6 to 1.0 ppm after 24 houres of chlorination. 5. Coliform groups were found at 49 out of 50 samples (98.0%) before chlorination when 100ml well waters was tested by membrane filter technique and 15 wells(30.0%) were potable for drinking within 24 houres after chlorination. 6. Coliform groups positves were 23 out of 26 samples (88.5%) with no residual chlorine, 12 out of 16 samples (80.0%) with 0.1 to 0.5ppm and none out of 9 with 0.6 to 1.0ppm.

• Toxicological Research
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• 제33권4호
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• pp.291-297
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• 2017

This study was performed to investigate the dose-response relationship between average daily cadmium dose (ADCD) from rice and the occurrence of urinary cadmium (U-Cd) in individuals eating that rice. This was a retrospective cohort designed to compare populations from two areas with different levels of cadmium contamination. Five-hundred and sixty-seven participants aged 18 years or older were interviewed to estimate their rice intake, and were assessed for U-Cd. The sources of consumed rice were sampled for cadmium measurement, from which the ADCD was estimated. Binary logistic regression was used to examine the association between ADCD and U-Cd (cut-off point at $2{\mu}g/g$ creatinine), and a correlation between them was established. The lowest estimate was $ADCD=0.5{\mu}g/kg\;bw/day$ [odds ratio (OR) = 1.71; with a 95% confidence interval (CI) 1.02-2.87]. For comparison, the relationship in the contaminated area is expressed by $ADCD=0.7{\mu}g/kg\;bw/day$, OR = 1.84; [95 % CI, 1.06-3.19], while no relationship was found in the non-contaminated area, meaning that the highest level at which this relationship does not exist is $ADCD=0.6{\mu}g/kg\;bw/day$ [95% CI, 0.99-2.95]. Rice, as a main staple food, is the most likely source of dietary cadmium. Abstaining from or limiting rice consumption, therefore, will increase the likelihood of maintaining U-Cd within the normal range. As the recommended maximum ADCD is not to exceed $0.6{\mu}g/kg\;bw/day$, the consumption of rice grown in cadmium-contaminated areas should not be more than 246.8 g/day. However, the exclusion of many edible plants grown in the contaminated area from the analysis might result in an estimated ADCD that does not reflect the true level of cadmium exposure among local people.

• Genomics & Informatics
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• 제19권3호
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• pp.31.1-31.9
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• 2021

Leptospirosis is a zoonotic disease caused by spirochetes from the genus Leptospira. In Thailand, Leptospira interrogans is a major cause of leptospirosis. Leptospirosis patients present with a wide range of clinical manifestations from asymptomatic, mild infections to severe illness involving organ failure. For better understanding the difference between Leptospira isolates causing mild and severe leptospirosis, illumina sequencing was used to sequence genomic DNA in both serotypes. DNA of Leptospira isolated from two patients, one with mild and another with severe symptoms, were included in this study. The paired-end reads were removed adapters and trimmed with Q30 score using Trimmomatic. Trimmed reads were constructed to contigs and scaffolds using SPAdes. Cross-contamination of scaffolds was evaluated by ContEst16s. Prokka tool for bacterial annotation was used to annotate sequences from both Leptospira isolates. Predicted amino acid sequences from Prokka were searched in EggNOG and David gene ontology database to characterize gene ontology. In addition, Leptospira from mild and severe patients, that passed the criteria e-value < 10e^-5 from blastP against virulence factor database, were used to analyze with Venn diagram. From this study, we found 13 and 12 genes that were unique in the isolates from mild and severe patients, respectively. The 12 genes in the severe isolate might be virulence factor genes that affect disease severity. However, these genes should be validated in further study.

• 한국물환경학회지
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• 제25권2호
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• pp.205-211
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• 2009

In this study, the membrane filter method was compared to the MPN method for the analysis of total coliforms from raw water using raw test waters and controls including 6 standard strains of coliforms, and the various factors were analyzed on the detection of general and fecal origin coliforms. The range of error rate for the detection of 5 standard strains using the membrane filter and the MPN methods was 0 to 6% and 45 to 133%, respectively. The error rate of the membrane filter method was lower than that of the MPN method. The membrane filter method (m-Endo) showed 10% (11 out of 111) of difference for the detection sensitivity of coliforms isolated from raw water compared to the MPN method (BGLB). The membrane filter method was less affected by the factors including temperature, turbidity, charcoals of powder form, contamination, and reverse pressure. In conclusion, the membrane filter method is a better method for the analysis of total coliforms from raw water than the MPN method, considering the accuracy of detection and the tolerance to various experimental factors.

• 항공우주정책ㆍ법학회지
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• 제27권1호
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• pp.103-122
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• 2012

오늘날 우주과학과 기술의 급격한 발달로 선진국을 비롯한 국제사회에서는 우주활동을 통한 다양한 서비스와 이익을 제공되는 반면, 각종 우주물체의 충돌과 폐기물 증가 등으로 인해 인류의 활동과 우주환경 보존면에서 피해발생 가능성이 높아지고 있다. 우주활동으로 인한 사고 및 위험으로부터 피해를 입은 자에게 정당하고 충분한 배상을 해주기 위해 현재의 국제법 질서를 형성하고 있는 우주조약과 우주책임협약의 내용을 먼저 검토하고, 이를 토대로 배상의 핵심적인 요건이 되고 있는 손해의 개념과 범위를 제시하였다. 손해의 개념은 육체적 침해만이 아니라 정신적 사회적 안녕의 침해가 포함된다고 보아야 할 것이다. 따라서 고통을 수반하는 정신적 침해도 당연히 손해의 범주에 포함된다고 할 수 있을 것이다. 따라서 책임협약상 인적 손해로는 사망은 물론 우주활동의 결과로 희생자들이 입은 육체적, 정신적 손해에 대해 직접손해이던 간접손해이던 배상할 의무가 있다. 이 근거에 의해 실제로 피해 배상을 청구할 때 그 피해자는 사고가 일어나지 않았던 상태로 회복하는 것이 최선의 보상이라는 개념과 연결된다고 볼 수 있다. 아울러, 환경오염의 배상 가능성, 위성자료 전송과 관련된 문제, 손해발생의 장소 등과 같은 문제들에 대한 논의를 시도하였다. 또한, 우주법재판소와 지역적 협력 기구를 설립하는 방안을 제안한다.