• The Journal of Korean Society for School & Community Health Education
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• v.2 no.1
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• pp.31-40
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• 2001

A study of fluoride effects on teeth of school children was conducted in order to determine the usefulness of fluoride for preventing dental caries. Nine hundred and thirty six(936) elementary school children were selected from Chongju where children drank fluoridated water. Eight hundred and thirty six(836) from Seoul where children applied fluoride topically, and eight hundred and three(803) from Kumi where the children drank non fluoridated water(control). DMFs of school children were compared by the sources of fluoride. This study was conducted from May 1, through June 15, 2000. The results are summarized as follows; 1. The DMF rate of male school children topically applying fluoride was 51.4%, that of female children was 56.1%, and that of both males and females was 54.0%, The DMF rate of male children of control group was 72.4%, that of females was 77.5% and that of both males and females was 74.8%. 2. The DMF rate of male children drinking fluoridated tap water was 56.1%, that of females was 54.1%, and that of both males and females was 55.5%. The rates of control group were 72.4% for males, 77.5% for females and 74.8% for male and female children respectively. 3. The difference of DMF rates between the group of children who drank fluoridated water and applied fluoride topically, and control group was statistically significant. 4. The difference of DMF rates between the children who drank fluoridated water and the children who applied fluoride topically were not statistically significant. 5. The difference of DMFT rates between 5th graders who applied fluoride topically and the 5th graders of control group was not statistically significant. However, the difference of DMFT rates of the 6th graders who applied fluoride topically and the same graders of control group were statistically significant. The difference of DMF rates between 5th and 6th graders who drank fluoridated tap water and the same graders of control group was statistically significant. 6. The difference of DMFT rates between children drinking fluoridated tap water and children applying fluoride topically was statistically significant.

• Journal of Korean Society on Water Environment
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• v.27 no.2
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• pp.200-209
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• 2011

The purpose of the study is to optimally manage sewage treatment plant with analysis of phosphorus contribution and improvement of water quality contributing rate in the effect of inflowing point of effluent and Pal-Dang lake after reducing T-P discharge from large scale public sewage treatment plant at upstream of Pal-Dang lake. Also, this study, for enforcement of T-P in effluent, plans optimal management of effluent T-P through examining propriety of environmental, technological, and economical aspect such as water quality standard of domestic and foreign T-P and related policy. In regarding optimal management of T-P discharged from public sewage treatment plant located in upstream of Pal-Dang lake, the study drew following conclusions. With the optimal management of public sewage treatment plant, it showed that a pollution level became higher in the order of Sumgang E in South-Han river, C in Dalcheon, B1 B2, A in North-Han river, and J in Kyungancheon, and it is required reduction of T-P first. The highest value in analysis of benefit-costs from sewage treatment plant in the selected research area was Kyungan B, and the others are with the order of Jojong A, Bokha A, Kyungan A, and Yanghwa A. With result of this study, all 14 areas are required more enforced phosphorus treatment. The study resulted that the most top priority areas were Hangang F, Sumgang B, and Gyungan A, top priority areas were Bokha A, Dalcheon B, and Cheongmi A, priority areas were Hangang E, Heukcheon A, Gyungan B, and Jojong A, and potential areas were Sumgang A, Yanghwa A, Dalcheon A, and Hangang D. It seems to be appropriate to apply 0.2 mg/L of T-P treatment for water supply source reservation, 0.5 mg/L for the other areas by locally, and 0.2~0.5 mg/L for biological nitrogen phosphorus treatment method and 0.5~1 mg/L for Conventional Activated Sludge by technologically. Also, it may be appropriate to apply 0.2 mg/L for the most top priority area(I), 0.3 mg/L for the top priority area(II), 0.4 mg/L for priority area(III), and 0.5 mg/L for potential area(IV) by the separation of priority area.

• Journal of Korea Water Resources Association
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• v.30 no.4
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• pp.367-377
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• 1997

In order to set public policy to overcome 'water crises' on both quantity and quality of water, we looked into the national-economic role of Korea water utility by two approaches. First, we examined the relationship between water consumption and economic growth during 1978-94, a period of rapid increase in water consumption caused by prompt industrialization and urbanization. The price and income elasticities of aggregate and sectoral demand for water were estimated. Second, we developed a static input-output(I-O) framework for analysing water issues in the short run. In addition, we discussed two topics in its application: i) sectoral failure(shortage) costs by supply-driven I-O model, ii) Leontief price model's sectoral pervasive effects of price due to rise in water rate. In conclusion, we found that investments to water sector and water shortage has a big influence on the standard of living and industrial production. Also we found that raising water rate to encourage conservation or to create investment funds decreases demand for water significantly but has a small influence on overall price levels.

• Journal of Korean Society on Water Environment
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• v.39 no.3
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• pp.231-239
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• 2023

Public sewage treatment facilities are a necessary infrastructure for public health that treat sewage generated in cities and basin living areas and discharge it into rivers or seas. Recently, the role of public sewage treatment is receiving attention as a place of use of wastewater-based epidemiology (WBE), which analyzes human specific metabolic emissions or biomarkers present in sewage to investigate the environment to which the population is exposed in the water drain. WBE is mainly applied to investigate legal and water-law drug use or to predict and analyze the lifestyle of local residents. WBE has also been applied to predict and analyze the degree of infectious diseases that are prevalent worldwide, such as COVID-19. Since sewage flowing into public sewage treatment facilities includes living information of the population living in the drainage area, it is easy to collect basic data to predict the confirmation and spread of infectious diseases. Therefore, it is necessary to establish a new role of public sewage treatment facilities as an infrastructure necessary for WBE that can obtain information on the confirmation and spread of infectious diseases other than the traditional role of public sewage treatment. In South Korea, the sewerage supply rate is about 95.5% and the number of public sewage treatment facility is 4,209. This means that the infrastructure of sewerage is fully established. However, to successfully drive for WBE , research on monitoring and big-data analysis is needed.

• Journal of dental hygiene science
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• v.6 no.2
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• pp.133-138
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• 2006

To find out influence of water fluoridation program on the economic benefit effect, this study analyzed comparatively dental treatment indicators obtained from dental clinics at Sangdang-gu in Chenongju City, fluoridated community and Manan-gu in Anyang City, non-fluoridated community, from January 1, 2003 to the end of June, and the results are as follows: 1. If water fluoridation program is carried out in Anyang, non-fluoridated community, the number of treatment from caries and disease of tissues around dental pulp and root apex from age 6 to 18 for the first half of year 2003 is expected to decrease by 1,272, 636 for low estimation, and 1,908 for high estimation. And the treatment cost is expected to decrease by 40,888,000 Wons, 20,444,000 Wons for low estimation, and 61,333,000 Wons for high estimation. 2. Assuming that water fluoridation program is spread to all over the country, the number of treatment per year is expected to decrease by 2,492,018, 1,246,009 for low estimation, and 3,738,027 for high estimation. And the treatment cost is expected to decrease by 80,105,075,000 Wons, 40,052,537,000 Wons for low estimation and 120, 157,612,000 Wons for high estimation respectively. 3. For Yeong-un water supply management office which has 48,925 water supply personnel, the benefit/cost rate was 2.9 times, and for Jibuk water supply management office which has 239,751 water supply personnel, the benefit/cost rate was 9.0 times. As the water supply personnel increased, the cost increase of water fluoridation program was little and as the scale got large, the economic effect was very large. Improving national oral health is thought to be associated with expense retrenchment of oral health insurance financial. So it may need to extend using tap water to all the area of the country and additionally establish confidence through an active public relations and education of water fluoridation program.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.565-570
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• 2001

Annually, Taiwan generates approximately 2 million tons of inorganic wastes in the form of sludge, fly ash and slug. To increase the added value of waste and maintain the increasingly insufficient supply of natural gravel, large public construction projects account for this large demand each year. future architectural trends are leading towards high-rise buildings. In light of the above, Center for Environmental, Safety and Health Technology Development, Industrial Technology Research Institute has developed the technology of manufacturing cold-bonding, sintering and bloating types of lightweight aggregates with a specific gravity ranging between 0.7~1.7, water absorption rate < 30%. The lightweight aggregate verified by physical property tests can be used as a substitute for the natural aggregate, which generally appears in replacing gravel in concrete, soundproofing and heat insulation materials. Doing so would not only moderate waste disposal problems, but also achieve the goal of resource recovery.

• Korean Journal of Mineralogy and Petrology
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• v.33 no.3
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• pp.233-242
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• 2020

As studies and developments of nano-material increase, the release of the nano-sized material to water environment increase. Especially, silver nanoparticles have been found as dissolved and particulate state since nano-silver particle have been intensively used in industrial and our living environment due to the anti-bacterial effect of the nano-particles. The silver nano-particles and silver ion gives adverse effect on ecology and US-EPA set a secondary drinking water standards as 0.1 mg/L. Current study focused on the analysis of silver in groundwater, small scale water supply systems in Gyeongbook area. The results have been compared with the secondary drinking water standards and discussed at the point of characteristics of the local area and purpose of use of the water sample. Among the total of 298 samples, 2 samples exceed the secondary drinking water standards of EPA, 0.64% rate. Community drinking water and simplified water service showed relatively high detection rate and groundwater gave relatively higher concentration of silver indicating anthropogenic source and natural source could contribute simultaneously on groundwater.

• Journal of Environmental Health Sciences
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• v.17 no.1
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• pp.136-162
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• 1991

This thesis is a study on the change and the process of the development of the hygiene administration during the period of modernization of our nation which promoted by the open door policy of our country chiefly under the pressure of the foreign countries. During that period Korea had reorganized the old political system radically and introduced the western medical system. Through the close study of literature concerning the system of the hygiene administration, the laws of health and hygiene, the environmental sanitation organizations and their practical activities the author obtained the conclusions as following 1. The government passed around 40 laws of health and hygiene from the time when the bureau of hygiene was founded in 1894 to the annex of Korea to Japan. Most of the laws were believed to be established by the enforecement of Japanese government. When the epidemics were prevailing, a decree for the prevention of the epidemics was proclaimed by the Japanese president of the headquarters of national police. It is shown well that the sovereignty of Korea had been deprived. 2. After the armex of Korea to Japan, the hygiene police and the general police belonging to the bureau of national police shared the tasks of health and hygiene. This was a temporary system which had existed just during the colonial period. As for the water-supply which is the most important facility among the various environmental hygiene facilities, the rate of supply was remarkably high in Japanese rather than in Korean. 3. During the period of American military administration, it is notable that the division of hygiene in the bureau of national police was replaced by the bureau of hygiene. This period is regarded as the turning point when hygiene administration was operated by means of education along with the introuction of American system of public health. 4. Ever since the foundation of the republic government, the laws of health and hygiene which had been established during the colonial period have been put into operation without rriuch change except several regulations concerning food.

• Journal of agricultural medicine and community health
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• v.9 no.1
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• pp.56-66
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• 1984

Giardia lamblia is a pathogenic flagellate causing intestinal disorders such as diarrhea, abdominal pain and malabsorption of nutrients. Giardia is mainly infected by the ingestion of contaminated foods per os. Craun (1979) has recently reported that mass infection of this flagellate through the contaminated water supply systems is one of public health hazards. Also, so-called traveller's diarrhea is sometimes caused by Giardia infection (CDC, U.S.A., 1971). However, a few epidemiological studies figuring out the mode of infection or control measures of Giardia infection has been done so far in Korea. The present study was aimed to know the prevalence of Giardia infection in several Korean populations, detectability of this flagellate in water systems and the viability of the cysts against sewages and disinfectants applying to drinking water. In the present study, 388 stool specimens from orphanage children in Chun-joo, Chung-joo, On-yang and Chun-an areas and 538 stool specimens from inhabitants in Woo-do, In-chon, and Chun-joo were examined by formalin-ether concentration technique to detect out Giardia cysts. On the other hand, water samples from 14 sites of Han River and its tributaries were collected in May through July, 1984. Fifty liter of water sample in each sampling site was then filtered through water filtering system deviced by U.S. Environmental Proutection Agency and the sediments rinsed out from the thread rolls, a part of water filtering system, were examined to detect out the Giardia cysts. In order to observe the viability of Giardia cysts in the sewage samples, the cysts were treated in it at $4^{\circ}C$ or $25^{\circ}C$ for 7 through 28 days. For this purpose, the cysts were also exposed to various concentrations of disinfectants such as chlorine, iodine and ozone gas for proper time intervals. After treatment, the viability test of the Giardia cysts were carried out by method of Rice and Schaefer (1981) with minor modification. The results obtained in this study were as follows : 1) The detection rates of G lamblia cysts in the stool specimens were 18.3% in orphans and 4.3% in general examinees. 2) The prevalences of Giardia Infection were higher in the young age groups than in-adults. The highest positive rate was 18.4% in the age group less than 10. 3) Of 14 water specimens sampled from Han River system and its tributaries around the Seoul area, the Giardia cysts were detected from 4 samples, and no cyst was found in the water supply systems. 4) The cysts treated in the sewage survived for 28 days at $4^{\circ}C$ and for 13 days at $25^{\circ}C$. 5) The cysts were completely destroyed within 60 minutes by exposure to 8 mg/l of residual chlorine at 4g and within 30 minutes by exposure to the same concentration of chlorine at $25^{\circ}C$. 6) The cysts were all dead when exposed to 1 mg/1 of iodine for 60 minutes at $4^{\circ}C$ or $25^{\circ}C$. 7) The cysts were destroyed after 10 minute exposure in 0.15 mg to 0.25mg of residual ozone gas per liter. Summarizing the above results, it is considered that Giardia infection is regarded as water-borne disease and the cysts are able to be controlled by the application with the disinfectants in the water supply systems.

• Journal of Soil and Groundwater Environment
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• v.17 no.2
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• pp.37-46
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• 2012

This study was conducted to identify groundwater recharge and discharge amounts of a representative urban-rural composite area located in Yongin city, Kyounggi-do, Korea. Groundwater recharge would be affected by mainly two processes in the study area: rainfall and leakage from public water pipelines including water-supply and sewage system. Groundwater recharge rate was estimated to be 13.5% by applying annual groundwater level data from two National Groundwater Monitoring Stations to the master regression curve method. Subsequently, the recharge amounts were determined to be $13,253{\times}10^3m^3/yr$. Leakage amounts from water-supply and sewage system were estimated to be $3,218{\times}10^3$ and $5,696{\times}10^3m^3/yr$, respectively. On the whole, a total of the recharge amounts was $22,167{\times}10^3m^3/yr$, of which 60% covers rainfall recharge and 40% pipeline leakage. Groundwater discharge occurred through three processes in the composite area: baseflow, well pumping, and discharge from urban infrastructure including groundwater infiltration into sewage pipeline and artificial extraction of groundwater to protect underground facilities from submergence. Discharge amounts by baseflow flowing to the Kiheung agricultural reservoir and well pumping were estimated to be $382{\times}10^3$ and $1,323{\times}10^3m^3/yr$, respectively. Occurrence of groundwater infiltration into sewage pipeline was rarely identified. Groundwater extraction amounts from the Bundang subway line as an underground facility were identified as $714{\times}10^3m^3/yr$. Overall, a total of the discharge amounts was determined to be $2,419{\times}10^3m^3/yr$, which was contributed by 29% of artificial discharge. Even though groundwater budget of the composite area was identified to be a surplus, it should be managed for a sound groundwater environment by changing deteriorated pipelines and controlling artificial discharge amounts.