• Journal of Environmental Health Sciences
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• v.30 no.2
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• pp.98-103
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• 2004

To evaluate the quality of drinking water and contamination sources in a rural community, this study was carried out on the summer of 2003 at Shin-Dong Myun, Chun-Cheon, Gang-Won province. Seventy three drinking water samples were collected from three different types of water supply systems. Sources of contamination were identified and the public perception of water quality area were evaluated. The findings of this study are as follows; Drinking water was mainly obtained from Local Water and Simple Piped Water Supply Systems, and pollution sources varied over the study area. Most of residents (＞63%) were satisfied with the quality of drinking water and could not identify any contamination sources. Corresponding to this perception, measured water quality parameters generally met the Drinking Water Quality Standards (＞64%). However, approximately 35.6% of samples exceeded the regulation for Nㅒ$_3$$^{-}$$_{-}$N, coliform, and general bacteria. The water quality was significantly different among the three water supply systems, and between the potentially contaminated areas and the rest of the areas (p＜0.05). In the potentially contaminated areas, the levels of coliform and general bacteria contamination were significantly higher than the rest of the areas (p＜0.05). The coliform and general bacteria values of Simple Piped Water were significantly higher than Own Piped Water＇s, and the NO$_3$$^{-}$$_{-}$N values of Own Piped Water were significantly higher than those of water＇s (p＜0.05). Based on this study, NO$_3$$^{-}$$_{-}$N, coliform, and general bacteria were identified as a major problem of drinking water. To regularly manage drinking water supply systems, to identify contamination sources, and to add drainage systems are required in the study area.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.3
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• pp.431-441
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• 2006

This study investigated the physiological characteristics of biofilm microorganisms formed onto the different drinking water distribution pipe surfaces. The simulated drinking water distribution pipe system which had several PVC, STS 304, and GS coupons was operated at flow velocity of 0.08 m/sec (Re 1,950) and 0.28 m/sec (Re 7,300), respectively. At velocity of 0.08 m/sec, the number of viable heterotrophic bacteria in the biofilm over the 3 months of operation averaged $3.3{\times}10^4$, $8.7{\times}10^4$, and $7.2{\times}10^3CFU/cm^2$ for PVC, STS, and GS surfaces, respectively. The number of attached heterotrophic bacteria averaged $1.4{\times}10^3$, $5.6{\times}10^2$, and $6.5{\times}10^2CFU/cm^2$ on PVC, STS, and GS surfaces at the system with relatively high flow velocity of 0.28m/sec. The changes of physiological profile of biofilm-forming microorganisms were characterized by community-level assay that utilized the Biolog GN microplates. Biofilms that formed on different pipe surfaces displayed distinctive patterns of community-level physiological profile (CLPP), which reflected the metabolic preference for different carbon sources and/or the utilization of these carbon sources to varying degrees. The CLPP patterns have shown that the metabolic potential of a biofilm community was different depending on the pipe material. The effect of the pipe material was also characterized differently by operation condition such as flow rate. At flow velocity of 0.08 m/sec, the metabolic potential of biofilm microorganisms on GS surface showed lower levels than PVC and STS biofilms. For biofilms on pipe material surfaces exposed to water flowing at 0.28 m/sec, the metabolic potential was in order of PVC>GS>STS. Generally, the levels of the bacterial biofilm's metabolic potentials were shown to be notably higher on pipe surfaces exposed to water at 0.08 m/sec when compared to those on pipe surfaces exposed to water at 0.28 m/sec.

• Journal of Microbiology and Biotechnology
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• v.23 no.12
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• pp.1774-1778
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• 2013

Methylotrophs within biological activated carbon (BAC) systems have not received attention although they are a valuable biological resource for degradation of organic pollutants. In this study, methylotrophic populations were monitored for four consecutive seasons in BAC of an actual drinking water plant, using ribosomal tag pyrosequencing. Methylotrophs constituted up to 5.6% of the bacterial community, and the methanotrophs Methylosoma and Methylobacter were most abundant. Community comparison showed that the temperature was an important factor affecting community composition, since it had an impact on the growth of particular methylotrophic genera. These results demonstrated that BAC possesses a substantial methylotrophic activity and harbors the relevant microbes.

• Journal of Environmental Health Sciences
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• v.20 no.1
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• pp.54-61
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• 1994

This study was carried out to investigate the degree of contamination in private-drinking water supply (PDWS) and simple-piped water supply (SPWS), and to compare of water quality between them for 3 years from 1990 to 1992. The results of the study were as follows: 1. Private-drinking water supply (PDWS) (1) Field-Site (ㄱ) The items which were very significantly over the criteria (p<0.01), were temp., pH, NO-N, standard plate count (S.P.C.) and Coliform. (ㄴ) No. of households which were over the criteria, were 11.2~51.7% in temp., pH, NH$_3$-N and NO$_2$-N, and 83.1~93.3% in NO-N, S.P.C. and Coliform. (2) Moutain-Site (ㄱ) The items which were over the criteria, were NO$_2$-N (p<0.05), S.P.C. (p<0.01) and Coliform (p<0.01). (ㄴ) No. of households which were over the criteria, were 33.6 ~ 75.6% in NO$_2$-N, S.P.C. and Coliform. (3) No. of households which were fit to the criteria of all items, were 9.0% in field-site and 14.1% in mountain-site. 2. Simple-piped water supply (SPWS) (1) The items which were very significantly over the critera (p<0.01), were standard plate count (S.P.C.) and Coliform. (2) The water qualities of adjacent and remote samples were better than those of source samples. (3) Residual chloride was not detected in any sample. In conclusion, rural community requires to be continually performed the policy of safety drinking water supply, and to be devised an epoch-making counterplan for the level-up of simple-piped water supply (SPWS), espically on the method of disinfection.

• Korean Journal of Environmental Biology
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• v.18 no.1
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• pp.53-61
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• 2000

In order to characterize the genetic diversity of bacterial community in groundwater, samples were collected from used for drinking water and polluted with heavy metal wastewater in Seoul city and natural cave of Kangwondo. The DNA was amplified with 165 rDNA-based primers by use of the PCR, and then analysed ARDRA (amplified ribosomal DNA restriction analysis). Restriction endonuclease analysis patterns of amplified 165 rDNA in drinking water and wastewater relatively showed high genetic diversity in situ and drinking groundwater. The number of DNA fragments varied with in situ and drinking water. This method of ARDRA of bacterial communities in groundwater could be used for a quick assessment of genotypic changes between different locations reflecting different environmental conditions and the diversity reflected pollution of groundwater (natural cave water>drinking water>waste water, as in order of grade). [Genetic diversity, Groundwater, 165 rDNA, PCR, ARDRA].

• Korean Journal of Health Education and Promotion
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• v.27 no.4
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• pp.113-121
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• 2010

Objectives: The study sought to identify the perception of schoolchildren's parents concerning an approval on the expansion implementation of community water fluoridation program in Gimhae, Korea. Methods: Questionnaires were distributed to schoolchildren's parents in Gimhae in 2008. Responses were collected from 1,703 parents. The standard questionnaire of Ministry of Health and Welfare was used and items were socioeconomic variables, water used for drinking and cooking, awareness on the fluoridation program and approval on the expansion implementation of fluoridation program at the region of Myeongdong water plant. Significance was analyzed by chi-square test and multiple logistic analysis. Results: Of parents, 1.9% used plain tap water and 39.8% used boiled tap water for drinking and 50.0% used tap water for cooking. 58.0% of parents were aware of fluoridation program with 27.1% being aware of the implementation of the program in Gimhae. 74.5% approved the expansion implementation of the program to the region of Myeong-dong water plant. Significant variables associated to approving the expansion implementation of program were age, gender, residence period in Gimhae, occupation and awareness of the program. Conclusion: The expansion implementation of fluoridation program in Gimhae is desirable for caries prevention because of the majority of schoolchildren's parents' approval.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.6
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• pp.767-777
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• 2012

Annular Biofilm Reactor (ABR) equipped with coupons of three different pipe materials (STS 304, PVC, PE) was used to generate drinking water biofilm samples. The level of assimilable organic carbon (AOC) during the sample generation period was $37.3{\mu}g/L$, and this level did not seem to be low enough to limit the formation of biofilm in this study. Terminal-restriction fragment length polymorphism (T-RFLP) analyses determined T-RF profile as early as 3 h of exposure on PVC coupons. Average surface roughness ($R_a$) measured by atomic force microscopic analyses was 125.7 nm for PVC, and this value was higher than for STS (71.6 nm) and PE (74.0 nm). However, biofilm formation was faster on STS (6 h) than on PE (12 h), which indicated that surface roughness might not be the only factor that controlled the initiation of biofilm development. Upon detection of the T-RF peaks, richness (S) and diversity indices such as Shannon (H) and Simpson (1/D) demonstrated a rather slow increase until 48 h followed by rapid increase regardless of the pipe materials. Differences of microbial community structures among the biofilm samples were determined based on the cluster analysis using Jaccard coefficients (Sj). Biofilm communities could be divided into two distinct groups according to the exposure time regardless of the pipe materials. First group contained a young (< 48 h) biofilm samples (10 out of 11) but second group contained a mature (${\geq}$ 48 h) samples (11 out of 14). Results suggested that, due to the complexity of biofilm, the targeting of the first group of cluster was crucial for optimizing the management of drinking water distribution systems and controlling microbial growth.

• Korean Journal of Clinical Laboratory Science
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• v.46 no.1
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• pp.17-21
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• 2014

The prevalence of hepatitis A virus (HAV) in a certain community reflects that community's living standard and hygienic condition. The seroprevalence rate of IgG anti-HAV has been changing with regions and times. In this study, we aimed to study the difference of seroprevalence of IgG anti-HAV according to sex, age and type of drinking water, and to know the vaccination rate and seroconversion rate for vaccinated subjects in Busan. A total of 644 samples were analyzed. The overall seroprevalence rate of IgG anti-HAV was 35.4% (228/644). There was no significant difference in sex (male 39.8%, female 32.7) (p>0.05). According to age, seroprevalence rate of anti-HAV were 55.0% in subjects aged 5~9 years old, 47.8% in 10~14 years old, decreced to 10.6% in 15~19 years old, 1.0% in 20~24 years old, 0.0% in 25~29 years old and increced with advacing ages ; 14.7% in 30~34 years old, 39.4% in 35~39 years old, 67.3% in 40~44 years old, 94.1% in 45~49 years old, 100.0% over 50 years (p<0.001). The seroprevalence of IgG anti-HAV was no statistical difference according to the types of drinking water (p>0.05). The vaccinated subject was 42 case only in below 25 years old. The seroconversion rate after vaccination was 88.1%.

• Journal of Preventive Medicine and Public Health
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• v.22 no.4 s.28
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• pp.454-465
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• 1989

In a small island community with a population of less than 100 residents, nine persons died and five experienced severe illnesses during the period from November 1986 to May 1988. Their initial symptoms were sore throat and fever. Renal failure and hepatitis developed within one week after the onset. Oral mucosal ulcer developed in some cases. After one week, progressive respiratory failure and dyspnea developed evidently and severe respiratory distress and hypoxia preceded those fatal cases. Chest X-ray findings revealed bilateral diffuse multiple cystic lesion with occasional multiple large emphysematous bullae. Based on these features paraquat poisoning was diagnosed and route of poisoning was investigated. In three sources of drinking water, trace amount of paraquat was detected in November 1988, six months after the incidence of recent fatal case. In November 1988, soybean sauces and soybean pastes from 12 households were found contaminated with high concentration of paraquat, the cause could not be identified. The possibility of the contamination of drinking water as the cause of this mass poisoning has been suggested.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.6
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• pp.723-734
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• 2010

With a belief of high water quality production and less chemical usage, membrane technology including Microfiltration (MF), Ultrafiltration (UF), and Nanofiltration(NF) is being employed more and more in drinking water treatment process. However, due to higher energy consumption of UF and NF, MF is normally used for drinking water treatment especially in a plant of large scale. In this investigation, performance ofsand filtration and membrane filtration was compared regarding removal of various water quality parameters, such as TOC, DOC, KMnO4 consumption, THMFP, and HAAFP. Two lines of pilot plant have been operated, one of which line is a traditional advanced water treatment process which includes sedimentation, sand filtration, ozonation, and activated carbon, and the other line is an alternative treatment process which includes sedimentation with inclined plate, MF membrane, ozonation, and activated carbon. For the first about 4months of period, MF filtration showed similar or little bit higher performance than sand filtration. However, after about 4month later, sand filtration showed much higher performance in removing all parameters monitored in the investigation. It was found that sand filtration is a better option than MF filtration as far as microbial community is fully activated in sand filter bed.