• The Journal of Korean Society for School & Community Health Education
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• v.25 no.1
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• pp.17-28
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• 2024

Background & Objectives: This study aimed to examine the relationship between subjective health perception and health behaviors among adolescents, utilizing raw data from the 8th Korea National Health and Nutrition Examination Survey (2019-2021) while distinguishing between genders. Methods: The study employed data from the 8th Korea National Health and Nutrition Examination Survey (2019-2020), recruiting students from 1st to 3rd grades in middle and high schools nationwide. Through population stratification, sample distribution, and sampling stages, a final sample of 1,065 adolescents aged 12 to 18 years was selected. The collected data were analyzed using SPSS 28.0 (IBM Corp., Armonk, NY, USA) at a significance level of .05. Results: Regarding the general characteristics of the subjects, no statistically significant differences were observed among male students based on school, family structure, and income. However, among female students, a significant difference in subjective health perception was noted, with higher perception among high school students compared to middle school students (p=.001). Significant differences in health behaviors were identified based on family structure for male adolescents, where those living with both parents exhibited more health-promoting behaviors than single-parent adolescents (p=.011). However, no significant difference was observed among female adolescents. In terms of health behaviors related to gender, regular exercise was found to significantly impact subjective health perception in male adolescents (p=.013), while breakfast habits were identified as significant influencers for female adolescents (p<.001). Conclusions: This study revealed gender differences in subjective health perception and health behaviors among adolescents. Based on these findings, there is a perceived need for the development of health promotion programs tailored to the unique needs of male and female adolescents.

• Journal of Environmental Health Sciences
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• v.50 no.2
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• pp.83-92
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• 2024

Background: In this study, we investigate the rapid increase in environmental odors and notable rise in civil complaints near Dorim Stream in the Gwanak-gu area of Seoul. Objectives: This study aims to identify the causal compounds responsible for environmental odors in the Dorim Stream and investigate the structural characteristics of the stream that influence odor generation. Methods: The research methodology involved setting up 41 sampling points, selecting panels for direct sensory evaluation to assess odor intensity, measuring dissolved oxygen and hydrogen sulfide concentrations, and using all-in-one low-temperature desorption gas chromatography (ATD-GC) and thermal desorption-gas chromatography-mass spectrometry (TD-GC/MS) analysis to identify odor-causing compounds. Results: The evaluation of Dorim Stream revealed that in areas with complete meandering, there were lower dissolved oxygen levels (4.5±2.67 mg/L) and higher odor intensity (4.0±0.92), while in partially meandering sections, higher dissolved oxygen levels (7.8±1.15 mg/L) and lower odor intensity (2.8±1.06) were observed. Hydrogen sulfide levels measured with sensors increased with higher temperatures, especially in the afternoon hours (12:00~14:00). Acetaldehyde was the dominant odor compound detected in both the Bonglim Bridge (0.4 ppm) area and Guro Bridge area (0.867 ppm), with concentrations more than twice as high near Guro Bridge. Odor-causing compounds identified by TD-GC/MS indicated a pungent, sulfurous odor in the Guro Bridge area and a musty odor in the Bonglim Bridge area. Conclusions: This study categorizes and analyzes the sources of odor in Dorim Stream in Seoul based on meandering patterns and the distribution of sewage facilities, highlighting the potential odor issues associated with combined sewage systems and sewer junctions and suggesting policy improvements.

• Korean Journal of Environmental Biology
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• v.41 no.4
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• pp.720-734
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• 2023

To understand the spatiotemporal distribution pattern of zooplankton and the environmental factors influencing zooplankton abundance in Gomso Bay, major harvesting area of Manila clam (Venerupis philippinarum) in South Korea, zooplankton sampling was conducted four times in autumn (October 2022), winter (January 2023), early spring (March 2023), and spring (May 2023). Among the environmental factors of Gomso Bay, water temperature, chlorophyll a concentration (Chl-a), dissolved oxygen (DO), and pH observed different patterns, while salinity and suspended particulate matter(SPM) showed no significant statistical differences between the survey periods. The zooplankton in Gomso Bay occurred 33, 29, 27, and 29 taxonomic groups during each respective survey period. In October 2022 and May 2023, arthropod plankton were dominated, while in January and March 2023, protozoa were primarily dominant. Among the Arthropods, copepods including Acartia hongi, Paracalanus parvus s. l., Corycaeus spp., and Oithona spp. commonly found along Korean coastal areas of the Yellow Sea, were dominated. Cluster analysis based on zooplankton abundance indicated a single community (stable condition) in each season, attributed to low dissimilarity distances, while three distinct clusters (autumn, winter-early spring, spring) between seasons indicated a highly seasonal environment in Gomso Bay.

• Geophysics and Geophysical Exploration
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• v.27 no.3
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• pp.181-195
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• 2024

This tutorial explains that the static effect in the magnetotelluric (MT) survey is a physical phenomenon caused by charges accumulated on the boundaries of subsurface inhomogeneities. To facilitate understanding of the physical phenomenon, differences between static induction and charge accumulation on the boundary are explained and analyzed with help of schematic illustrations. Subsequently, from the electromagnetic (EM) integral equation formulation, it is clearly shown that the secondary electric field due to charges accumulated on the interface in the presence of the primary field appears as the static effect. Therefore, except in the cases of the layered earth or a two-dimensional earth with transverse magnetic (TM) mode excitation, the static effect always exists in MT responses and further, it is not 'static' but rather frequency dependent. Despite the fact that the static effect is a secondary electric field due to inhomogeneity, inevitable under-sampling in the frequency and spatial domains prevent the effect from being handled properly in numerical inversion. Therefore, considering the practical aspects of the MT survey, which cannot be a continuous measurement covering the entire survey area over a wide frequency band, a three-dimensional (3-D) inversion incorporating the static shift as a constraint with the Gaussian distribution is introduced. To enhance understanding of the integral equation EM modeling, the formulation of the 3-D integral equation and mathematical analyses of the Green tensor and scattering current are described in detail in the Appendix.

• Journal of Korean society of Dental Hygiene
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• v.8 no.2
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• pp.39-51
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• 2008

The research was conducted to 100 child patients selected by random sampling, which got a Dentocult-SM test in the first visit and then was being continuously managed, out of child patients of a pediatric clinic located in Gyeonggi-do. The period of there search is one year from June 2007 to May 2008, Using Dentocult-SM test, we analyzed the correlation between the distribution of dental plaque, a streptococcus mutans in saliva and condition of dental caries cavity in the teeth of child patients, then we measured the distribution of a streptococcusmutans. According to SM score, we applied incremental oral heath care for child patients to clinical and obtained the following results, 1. In terms of the age of child patients in research, the number of 3 years old patients was 29(lst ranked), the number of 2 years old patients was 28(2nd ranked). 2. The result of SM score showed that female child patients(52.0%) was higher than male ones in negative, male child patients(52.0%) was higher than female ones in mild, female child patients(68.2%) was higher than male ones in moderate, male child patients(57.1%) was higher than female ones in severe. 3. At the first visit, the SM score showed statistically remarkable difference between dt and dmft. We can also confirm the average of severe is the highest. 4. At the second visit, the SM score showed statistically remarkable difference among dt, ft, and dmft index We can also confirm the average of severe is the highest. 5. At the third visit, The SM score showed statistically remarkable difference among dt, ft, and dmft index We can also confirm the average of severe is the highest. 6. The comparison of dmft index differences to SM score showed statistically no remarkable difference in incremental oral heath care for negative and mild, In addition to that, we can confirm that the incremental oral heath care makes statistically remarkable differences in moderate and severe. 7. The comparison of dt index differences to SM score showed statistically no remarkable difference in incremental oral heath care for negative, mild, and moderate, In addition to that, we can con firm that the incremental oral heath care makes statistically remarkable differences in severe. 8. The comparison of mt index differences to SM score showed statistically no remarkable difference in incremental oral heath care for mild and moderate, In addition to that, we can confirm that the incremental oral heath care makes statistically remarkable differences m severe. 9. The comparison of ft index differences to SM score showed statistically no remarkable difference in incremental oral heath care for mild, In addition to that, we can confirm that the incremental oral heath care makes statistically remarkable differences in negative, moderate, and severe. 10. According to the comparison of dmft index to the age, the 4 years old patients showed the highest number(5.50 in the first visit and 6,08 in the second one). In the third visit, the 6 years old patients showed the highest number(7.00). By the above results, we can find that the incremental oral heath care by SM score makes the results of oral care better. Therefore, the improvement or maintenance in oral health of child patients needs continuing personal oral health management and regular systematic management focused on prevention by the specialist.

• Journal of the Korean earth science society
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• v.25 no.6
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• pp.428-442
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• 2004

Dustfall samples were collected by the modified American dust jar (bulk type) at 5 sampling sites in the Nakdong river area from lune 2002 to May 2003. Nineteen chemical species (Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Si, V, Zn, $Cl^-$, $NO_3^-$, $SO_4^{2-}$, and $NH_4^+$) were analyzed via the combination of ICP/AES, AAS, IC and UV. The purposes of this study were to qualitatively evaluate the chemical composition of dustfalls by examining their regional and seasonal distribution patterns. Computation of the enrichment factor showed that well-defined anthropogenic sources, particularly in Pb were found in the order Gamjeondong (industrial area), Wondong, Silla University, Samrangiin and Mulgum. The seasonal mean of soil contribution showed its highest value (16.3%) during the winter with an annual mean of 11.2%. The concentration ratio of [$SO_4^{2-}/NO_3^-$] was found to be highest (5.12) during the winter, while the lowest ratio value (3.30) was seen during the all. fall, Also regional equivalent ratios of [$SO_4^{2-}/NO_3^-$] were found in the order: Silla University (6.78), Gamjeondong (4.98), Mulgum (3.95), Wondong (3.85), and Samrangjin (2.87). Seasonal distribution of water soluble components for total dustfall were found in the order: spring (71.6%), summer (61.2%), fall (49.2%) and winter (48.6%) with a mean ratio of 57.6%. Regional contribution of sea salts of water soluble ions were found in the order: Silla university (34.5%), Gamjeondong (28.3%), Wondong (17.3%), Samrangiin (17.2%) and Mulgum (13.8%), the total mean contribution rate was 22.1%. As for the chemical composition of dustftll on the lower Nakdong river, there is a decreased influence of sea salt and artificial anthropogenic sources and increased influence of soil particle inland. Also, the total amount of deposition on the lower Nakdong river has decreased, with the river's surface serving as a confounding factor in resuspending dusts.

• Korean Journal of Ecology and Environment
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• v.52 no.4
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• pp.324-332
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• 2019

In this study, the possibility of a follow-up study on environmental pollution in domestic freshwater was identified by analyzing fish otoliths using Laser ablation-inductively coupled mass spectrometry (LA-ICP/MS). Fish otolith are known to be affected by the environment in which fish live. As a result, research on this subject is active in many countries; however, this is not the case in Korea. Therefore, in this study, the possibility of tracing environmental pollution using fish otoliths was identified by analyzing the components of metal elements used as indicators for environmental pollution. For the component analysis of metallic elements LA-ICP/MS, which can shorten analysis time by reducing the pretreatment process, was used. Sampling was conducted by dividing the research and the background area and carp, a freshwater species, was selected as the experimental fish species subject. Based on the established LA-ICP/MS conditions, the concentration of the metallic elements in the fish otoliths collected in the research area was 2202.9 mg kg^-1, 2.03 times higher than the 1,086.3 mg kg^-1 in the background area. All elements except for Li and U, were found to be higher in the research area than in the background area. Compared with the sediment measuring net analysis data, the distribution tendency of Zn, Pb, and Cu in sediment metal element concentrations in the two regions and distribution of metal element concentration in fish otoliths were similarly shown. These results confirm that fish otoliths can be used to track environmental pollutants, such as in sediments.

• Economic and Environmental Geology
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• v.36 no.2
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• pp.89-101
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• 2003

River deposits and farmland soils were analyzed to investigate the pollution level of heavy metals in the vicinity of the Goro abandoned Zn-mine. Surface (0-40 cm) and subsurface (40-100 cm) soils were collected around a main river located at the lower part of the Goro mine, and analyzed by ICP-MS for Cd, Cu, Pb, Zn and Cr after 0. 1N HCI extraction and by AAS for As after IN HCI extraction. Concentrations of cadmium and lead at the surface river deposits close to the mine were over the Soil Pollution Warning Limit (SPWL), and 43% of sample sites (6 of 14 samples) were over SPWL for As suggesting that river deposits were broadly contaminated by arsenic. Results from farmland soil analysis showed that surface soils were contaminated by heavy metals, while only arsenic was over SPWL at 50% of sampling sites. Main pollution mechanism around the Goro mine was the discharge of mine tailing and waste rocks from the storage site to the river and to adjacent farmland during flood season. Pollution Grades for sample locations were prescribed by the Law of Soil Environmental Preservation, suggesting that the pollution level of heavy metals around the Goro mine was serious, and the remediation operation fur arsenic and the isolation of mine tailing and waste rocks from river and farmland should be activated to protect further contamination. The area needed to clean up was estimated from pollution distribution data and the remediation methods such as a soil washing method and a soil improvement method were considered as the further remediation operation for arsenic contaminated soils and river deposits around the Goro abandoned mine.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.1
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• pp.35-45
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• 2002

Seasonal quantitative van Veen grab sampling was conducted to characterize the composition and structure of the benthic polychaete community inhabiting the shellfish farming ground of a coastal bay system of Jiniu Bay (Korea). A total of 132 polychaete species were identified and the polychaetes accounted for about $80\%$ of overall abundance of benthic animals. There was little significant seasonal difference in densities (abundances) of polychaetes, Maximum biomass was obseued in summer (August) and minimum value was recorded in winter (February) and spring (May). Conversely, diversity and richness were lowest in summer, indicating a seasonal variability in the polychaetous community structure, The cluster analysis indicated that such a seasonal variability resulted mainly from the appearance of a few small, r-selected opportunists in spring and the tubiculous species of the family Maldanidae in summer. On the other hand, several indicator species for the organically enriched environments such as Capitelia capitata, Notoniashs Jatericeus and hmbrineris sp. showed high densities during all the study period. Density and biomass of univariate measures of community structure were significantly lower in the arkshell-farming ground of the southern area than in the non-farming sites of the bay, A similar general tendency was also found in the spatial distributions of species diversity and richness. Principal component analysis revealed the existence of different groups of benthic assemblages between the arkshell-farming ground and non-farming sites, The lack of colonization of r-selected opportunists and/or tubiculous species in the former ground seemed to contribute to the spatial differences in the composition and structure of the polychaetous communities. Although finer granulometric composition and high sulfide concentration in sediments of the arkshell-farming ground and low salinity in the northern area were likely to account for parts of the differences, other environmental variables observed were unlikely. The spatial distribution of polychaetes in Jiniu Bay may be rather closely related to the sedimentary disturbance by selection of shells for harvesting in spring.

• Journal of Korean Society on Water Environment
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• v.34 no.2
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• pp.183-201
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• 2018

The tolerance of Korean benthic macroinvertebrates to organic pollution has been analyzed since the early 1990s. However, considering the fact that there have been related studies carried out in some European countries since the early 20th century, the history of the research in Korea is very short and there is still much knowledge to supplement. We revised the saprobic valency, the saprobic value and the indicator weight value of 190 benthic macroinvertebrates taxa through the data of water quality and individual abundance collected from 7,086 sampling units in Korea from 2008 to 2014. The individual abundance of Uracanthella (Ephemeroptera) as a representative, one of the most common and abundant taxa in Korea, showed a typical lognormal distribution to 5-day biochemical oxygen demand (BOD5) concentration, and a normal distribution to the class interval of BOD5 concentration according to saprobic series. The value combining the mean individual abundance and the relative frequency of occurrence was a more efficient indicator value than that of each property alone. Benthic Macroinertebrates Index (BMI) was newly proposed as a modification of the saprobic index of Zelinka and Marvan (1961). BMI showed extremely significant correlation (determination coefficient $r^2$ > 0.6, n = 569 sites) with the concentration of BOD5, and the coefficient was a little higher than those of the previous indices. Until now, there has been very little research on the assessment of biological integrity of benthic macroinvertebrates community in Korea. While continuing researches into improve the reliability of BMI, it is necessary to develop multimetric indices for evaluating the integrity, including the composition of species and functional guilds, and the richness and diversity of the community.