• Journal of Wetlands Research
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• v.24 no.3
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• pp.204-212
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• 2022

The LID technique began to be applied in Korea after 2009, and LID facilities are installed and operated for rainwater management in business districts such as the Ministry of Environment, the Ministry of Land, Infrastructure and Transport, and LH Corporation, public institutions, commercial land, housing, parks, and schools. However, looking at domestic cases, the application cases and operation periods are insufficient compared to those outside the country, so appropriate design standards and measures for operation and maintenance are insufficient. In particular, LID facilities constructed using LID techniques need to maintain the environment inside LID facilities because hydrological and environmental effects are expressed by material circulation and energy flow. The LID facility is designed with the treatment capacity planned for the water circulation target, and the proper maintenance, vegetation, and soil conditions are periodically identified, and the efficiency is maintained as much as possible. In other words, the soil created in LID is a very important design element because LID facilities are expected to have effects such as water pollution reduction, flood reduction, water resource acquisition, and temperature reduction while increasing water storage and penetration capacity through water circulation construction. In order to maintain and manage the functions of LID facilities accurately, the current state of the facilities and the cycle of replacement and maintenance should be accurately known through various quantitative data such as soil contamination, snow removal effects, and vegetation criteria. This study was conducted to investigate the current status of LID facilities installed in Korea from 2009 to 2020, and analyze soil changes through the continuity and current status of LID facilities applied over the past 10 years after collecting soil samples from the soil layer. Through analysis of Saturn, organic matter, hardness, water contents, pH, electrical conductivity, and salt, some vegetation-type LID facilities more than 5 to 7 years after construction showed results corresponding to the lower grade of landscape design. Facilities below the lower level can be recognized as a point of time when maintenance is necessary in a state that may cause problems in soil permeability and vegetation growth. Accordingly, it was found that LID facilities should be managed through soil replacement and replacement.

• Korean Journal of Environment and Ecology
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• v.36 no.6
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• pp.566-574
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• 2022

Heavy metals are one of the dangerous pollutants that threaten urban biodiversity due to their accumulation over a long period without being decomposed in vivo. Accordingly, there is a need for biological monitoring to compare accumulation concentrations in living organisms according to the degree of heavy metal exposure to evaluate heavy metal contamination in the air in urban areas. This study aims to examine the possibility of using nesting materials as heavy metal monitoring samples and determine the effects of heavy metals on Paridae. We installed 54 artificial nest boxes in the research areas that included campus green spaces (14), urban forests (11), and urban parks (29) on a university campus in Cheonan City, Chungcheongnam Province. The birds' use rate of artificial nest boxes was 11/14 (78.57%) in campus green spaces, 8/11 (72.72%) in urban forests, and 6/29 (20.68%) in urban parks. Moss materials were collected from collected nests, and the heavy metal accumulation characteristics of each type of urban green space and the effects of heavy metals on the success of fledging of Paridae were compared through heavy metal analysis. The analysis showed that the average concentrations of zinc and lead were 228.08±209.62 ㎍/dry g and 17.67 ± 6.72 ㎍/dry g, respectively. There was no significant difference in zinc concentration for each type of urban green space (Kruskal-Wallis test, p-value=0.28), but lead concentration showed a significant difference (Kruskal-Wallis test, p<0.05^*). Of the 21 Paridae, nests analyzed for heavy metals, fledging of birds was observed in 11 nests (52.38%). Fledging of birds observed in each urban green space type was 7 campus green spaces (77.78%), 6 in urban forests (85.71%), and 1 in urban park (20%), mainly in urban forests and green spaces on campus. Heavy metal concentrations were compared to check the effect of heavy metal accumulation on the successful fledging of Paridae, but there was no statistically significant difference (Zn: W=44, p-value=0.74, Pb: t=0.64676, df =7.2422, p-value=0.54). This study is a basic study using the nesting materials of Paridae as heavy metal monitoring samples, and it is determined that it can be used as basic data for non-invasive biological monitoring.

• Korean Journal of Ecology and Environment
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• v.56 no.4
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• pp.430-439
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• 2023

UV and O₃ are materials used in the water treatment process, and many studies have been reported to remove organic matters, contaminants, and microorganisms. In this study, we were investigated effects of Chirnomidae (Chironomus flaviplumus, Chironomus riparius), which are contamination indicator species to exposure UV and O₃ for the survival rate, body color change and gene expression response. The survival rate of C. flaviplumus exposed to UV decreased to about 70% after 24 hours, and C. riparius about 50%. There was no change in the survival rate of C. flaviplumus exposed to O₃, and C. riparius decreased to 95% after 10 minutes of exposure, but there was no change during the subsequent exposure time. In addition, UV and O₃ exposure to the two species in body color faded in a time-dependent. In the HSP70 gene expression, C. riparius showed an increase in expression after UV exposure compared to the control group, and a significant difference was shown 12 hours after exposure (P<0.05). C. flaviplumus exposed to O₃ showed a relatively low expression compared to the control group, and showed a significant difference at 10 minutes and 1 hour after exposure (P<0.05). These results reported the ecotoxicological effects on Chironomidae according to UV and O₃ exposure. Therefore, the results of this study can be used as basic data to understand the effects of UV and O₃, which are disinfectants used in water treatment plants, on Chirnomidae entering plants.

• Korean journal of food and cookery science
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• v.23 no.5
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• pp.589-600
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• 2007

Recently, with the rapid expansion of the franchise restaurants, ensuring food safety has become essential for restaurant growth. Consequently, the need for food safety training and related material is in increasing demand. In this study, we identified potentially hazardous risk factors for ensuring food safety in restaurants through a food safety monitoring tool, and developed training materials for restaurant employees based on the results. The surveyed restaurants, consisting of 6 Korean restaurants and 1 Japanese restaurant were located in Seoul. Their average check was 15,500 won, ranging from 9,000 to 23,000 won. The range of their total space was 297.5 to $1322.4m^2$, and the amount of kitchen space per total area ranged from 4.4 to 30 percent. The mean score for food safety management performance was 57 out of 100 points, with a range of 51 to 73 points. For risk factor analysis, the most frequently cited sanitary violations involved the handwashing methods/handwashing facilities supplies (7.5%), receiving activities (7.5%), checking and recording of frozen/refrigerated foods temperature (0%), holding foods off the floor (0%), washing of fruits and vegetables (42%), planning and supervising facility cleaning and maintaining programs of facilities (50%), pest control (13%), and toilet equipped/cleaned (13%). Base on these results, the main points that were addressed in the hygiene training of restaurant employees included 4 principles and 8 concepts. The four principles consisted of personal hygiene, prevention of food contamination, time/temperature control, and refrigerator storage. The eight concepts included: (1) personal hygiene and cleanliness with proper handwashing, (2) approved food source and receiving management (3) refrigerator and freezer control, (4) storage management, (5) labeling, (6) prevention of food contamination, (7) cooking and reheating control, and (8) cleaning, sanitation, and plumbing control. Finally, a hygiene training manual and poster leaflets were developed as a food safety training materials for restaurants employees.

• Journal of Preventive Medicine and Public Health
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• v.3 no.1
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• pp.1-16
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• 1970

The present status of control measures for public health important helminthic infections in Korea was surveyed in 1969 and the following results were obtained. The activities of parasitic examination and Ascaris treatment for the positives which were done during 1966 to 1969 were brought in poor result and could not decrease the infection rate. It is needed to improve or strengthen the activities. The mass treatment activities for paragonimiasis and clonorchiasis in the areas which were designated by the Ministry of Health were carried out during 1965 to 1968 with no good results in decrease of estimated number of the patients. There were too many pharmaceutical companies where many kinds of anthelmintics were produced. It may be better to reduce the number of anthelmintics produced and control the quality. The human feces, the most important source of helminthic infections, was generally not treated in sanitary ways because of the poor sewerage system and no sewage treatment plant in urban areas and insanitary latrines in rural areas. The field soils of 170 specimens were collected from 34 areas out of 55 urban and tourist areas where night soil has been prohibited by a regulation to be used as a fertilizer, and examined for parasites contamination with the result of Ascaris egg detection in 44%. Some kinds of vegetables of 64 specimens each from the supply agents of parasite free vegetables and general markets were collected and examined for parasites contamination with the results of Ascaris egg detection in 25% and 36% respectively. The parasite control activities and the ability of parasitological examination techniques in the health centers of the country were not satisfactory. The budget of the Ministry of Health for the parasite control was very poor. The actual expenditure needed for cellophane thick smear technique was 8 Won per a specimen. As a principle the control of helminthic infections might be led toward breaking the chain of events in the life cycle of the prasites and eliminating environmental and host factors concerned with the infections, and the following methods nay be pointed out. 1) Mass treatment might be done to eliminate human reservoirs of an infection. 2) Animal reservoirs which are related with human infections night be eliminated. 3) The excretes of reservoirs, particularly human feces, should be treated in sanitary ways by the means of sanitary sewerage system and sewage treatment plant in urban areas and sanitary latrines such as waterborne latrine, aqua privy and pit latrine in rural areas. The increase of national economical development and prohibition of the habit of using night soils as a fertilizer might be very important factors to achieve the purpose. 4) The control of vehicles and intermediate hosts might be done by the means of prohibition of soil contamination with parasites, food sanitation, insect control and snail control. 5) The improvement of insanitary attitudes and bad habits which are related with parasitic infections night be done by the means of prohibition of habit of using night soils as a fertilizer, and improving eating habits and personal hygiene. 6) Chemoprophylactic measure and vaccination may be effective to prevent the infections or the development of a parasite to adult in the bodies when the bodies were invaded by parasites. Further studies and development of this kind of measures are needed.

• Journal of the Mineralogical Society of Korea
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• v.21 no.3
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• pp.227-237
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• 2008

Arsenic has recently become of the most serious environmental concerns, and the worldwide regulation of arsenic fur drinking water has been reinforced. Arsenic contaminated groundwater and soil have been frequently revealed as well, and arsenic contamination and its treatment and measures have been domestically raised as one of the most important environmental issues. Arsenic behavior in geo-environment is principally affected by oxides and clay minerals, and particularly iron (oxy)hydroxides have been well known to be most effective in controlling arsenic. Among a number of iron (oxy)hydroxides, for this reason, 2-line ferrihydrite was selected in this study to investigate its effect on arsenic behavior. Adsorption of 2-line ferrihydrite was characterized and compared between As(III) and As(V) which are known to be the most ubiquitous species among arsenic forms in natural environment. Two-line ferrihydrite synthesized in the lab as the adsorbent of arsenic had $10\sim200$ nm for diameter, $247m^{2}/g$ for specific surface area, and 8.2 for pH of zero charge, and those representative properties of 2-line ferrihydrite appeared to be greatly suitable to be used as adsorbent of arsenic. The experimental results on equilibrium adsorption indicate that As(III) showed much stronger adsorption affinity onto 2-line ferrihydrite than As(V). In addition, the maximum adsorptions of As(III) and As(V) were observed at pH 7.0 and 2.0, respectively. In particular, the adsorption of As(III) did not show any difference between pH conditions, except for pH 12.2. On the contrary, the As(V) adsorption was remarkably decreased with increase in pH. The results obtained from the detailed experiments investigating pH effect on arsenic adsorption show that As(III) adsorption increased up to pH 8.0 and dramatically decreased above pH 9.2. In case of As(V), its adsorption steadily decreased with increase in pH. The reason the adsorption characteristics became totally different depending on arsenic species is attributed to the fact that chemical speciation of arsenic and surface charge of 2-line ferrihydrite are significantly affected by pH, and it is speculated that those composite phenomena cause the difference in adsorption between As(III) and As(V). From the view point of adsorption kinetics, adsorption of arsenic species onto 2-line ferrihydrite was investigated to be mostly completed within the duration of 2 hours. Among the kinetic models proposed so for, power function and elovich model were evaluated to be the most suitable ones which can simulate adsorption kinetics of two kinds of arsenic species onto 2-line ferrihydrite.

• Journal of Korean Society of Forest Science
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• v.29 no.1
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• pp.20-53
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• 1976

For the purpose of detecting the capability of the trees to resist air pollution and of determining the tree species best suited for purification of polluted air, particularly with regard to $SO_2$ contamination, six following ornamental tree species were selected as experimental materials: i.e., Hibiscus syriacus L., Ginkgo biloba L., Forsythia koreana Nak., Syringa dilatata Nak., Larix leptolepis Gordon, and Pinus rigida Miller. The susceptiblities of the trees were observed and analyzed on the basis of area ratio of smoke injury spots to the total leaf area. The results of the experiments are as follows: I. The Susceptibilities to Sulfur Dioxide. (1) The decreasing order of tolerance to $SO_2$ by species was as follows: 1. Hibiscus syriacus 2. Ginkgo biloba, 3. Forsythia koreana, 4. Syringa dilatata, 5. Larix leptolepis, and 6. Pinus rigida. In general, Hibiscus syriacus and Ginkgo biloba can be grouped as the most resistant and Larix leptolepis and Pinus rigida as the least resistant and Forsythia koreana and Syringa dilatata as of intermediate resistance. (2) The sulfur content of the leaves treated by $SO_2$ increased in proportion to the increase of the concentration of the fumigation. The content in the coniferous species proved to be less than that of the broad-leaved species, but Ginkgo biloba proved to contain as much sulfur as broad-leaved species. (3) The earlier-stage leaves fumigated in June with the $SO_2$ concentration up-to-l-ppm showed that sulfur content increases in proportion to the increase of the concentration of the fumigation, but the difference between concentration was not so significant. (4) The later-stage leaves fumigated in October showed higher sulfur content than the earlier stage leaves, and a wider range of difference in sulfur content was detected among different concentrations. The limit of fumigation resulting in culmination of sulfur absoption in broad-leaved species, such as Syringa dilatata, Hibiscus syriacus, and Forsythia koreana proved to be around 0.6 ppm. (5) Due to the sprouting ability and the adventitious bud formation, the recovery from $SO_2$ fumigation was prominent in Hibiscus syriacus, Syringa dilatata, and Forsythia koreana. (6) The differences in the smoke spot color were recognized by species: namely, dirt-brown in Syringa dilatata, brilliant yellowish-brown in Pinus rigida and Ginkgo biloba, whitish-yellow in Hibiscus syriacus and reddish-brown in Forsythia koreana. (7) The leaf margins proved to be most susceptible, and the leaf bases of the mid-rib most tolerant. In both Ginkgo biloba and Larix leptolepis, the younger leaves were more resistant to $SO_2$ than the older ones. II. The ulfur Content of the Leaves of the Ornamental Trees Growing in the City of Seoul. (1) The sulfur contents in the leaves of the Seoul City ornamental trees showed a remarkably higher value than those of the leaves in the non-polluted areas. The sulfur content of the leaves in the non-polluted area proved to be in the following descending order: Salix pseudo-lasiogyne Leveille, Ginkgo biloba L., Alianthus altissima swingle, Platanus orientalis L., and Populus deltoides Marsh. (2) In respect to the sulfur contents in the leaves of the ornamental trees in the city of Seoul, the air pollution proved to be the worst in the areas of Seoul Railroad Station, the Ahyun Pass, and the Entrance to Ewha Womans University. The areas of Deogsu Palace, Gyeongbog Palace, Changdeog Palace, Changgyeong Park and the Hyehwa Intersection were least polluted, and the areas of the East Gate, the Ulchi Intersection and the Seodaemun Intersection are in the intermediate state.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.4
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• pp.351-358
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• 2008

Purpose: This study examined the recovery of the dentin-resin bonding strength, and the difference in the bonding strength after applying pH hemostatic agents at various pH. Materials and methods: Bosmin, Hemodent, Astregedent, and Visine were used as the hemostatic agents in this study. The Bosmin, Hemodent, and Astrigedent hemostatic agents are acidic, and the Visine hemostatic agent is neutral and is used as a decongestant. Ninety human molar teeth were used as the specimen. The teeth were sectioned using a diamond wheel until the dentin was exposed and wet ground by silica paper. The specimens were divided into two groups according to the hemostatic agent used. The specimens were then subdivided into 9 groups according to the application of re etching (R group) or rinsing only (N group). A commonly used resin bonding procedure was used in the control group. The resin bonding procedure was managed dentin using celluloid capsule. In addition, the shear bond strength was measured using an Instron. Results: In general, samples with the applied hemostatic agent, with the exception of Visine, had a slightly weak bond that was similar to the control group. In addition, the rinsing only (N) group had slightly weak bond that was similar to the re etching (R) group. Conclusion: The application of a hemostatic agent on the dentin surface does not affect the shear bond strength after application for a short time. In addition, rinsing only can recover the shear bond strength making other management procedures redundant, particularly re etching.

• Journal of Korean Society of Forest Science
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• v.90 no.4
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• pp.495-504
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• 2001

The objectives of this study were to understand the characteristics of Cd and Pb accumulation in various tissues of poplar species and the effects of ectomycorrhizal inoculation on the accumulation of above two heavy metals in the tissues. The mycelial inoculum of ectomycorrizal fungus, Pisolithus tinctorius was produced in peatmoss and vermiculite mixtures, and inoculated into potted soil with fresh cuttings of four species of Populus, P. alba ${\times}$ glandulosa (Pag). P. koreana ${\times}$ nigra var. italica (Pkn), P. nigra ${\times}$ maximowiczii(Pnm), and P. euramericana(Pe). The potted soils were added with 0, 30, and 80 ppm Cd, and 0, 50, and 300 ppm Pb. The cuttings were grown outdoors for about five months until the plants were harvested for measurement of growth, mycorrhizal infection, and metal contents in leaves, stems, and roots. The total dry weight of Pe treated with Cd and Pb was increased by mycorrhizal inoculation, while that of three other species was not affected by the inoculation. Cd was accumulated in the highest concentration in Pag and its concentration was increased by four times by mycorrhizal inoculation. The Pag accumulated Cd in the highest concentration in the leaves, while three other species accumulated Cd most in the roots. Pb was accumulated in the highest concentration in the roots of all the four species, while Pkn accumulated Pb in the leaves as much as in the roots. Without mycorrhizal inoculation Pe accumulated Pb most among the four species, while Pkn with mycorrhizal inoculation accumulated Pb two times more than in the same species without mycorrhizal inoculation. It was concluded that Pag was the most effective species among the four poplar species in Cd absorption from contaminated soil, and that Pe instead effectively absorbed Pb. Mycorrhizal inoculation increased the Cd accumulation in the tissues by four times in Pag and also increased Pb accumulation by two times in Pkn, with leaves being the major sites of metal accumulation. It may be possible to use these two poplar species in remedying the metal in the soil through the raking and removing the litter out of the contaminate site.

• Korean Journal of Microbiology
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• v.50 no.2
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• pp.101-107
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• 2014

Community-acquired antimicrobial resistant bacteria are an emerging problem world-wide. In Korea, resistant bacteria are more prevalent than in other industrialized countries. The aim of this study was to investigate the isolation frequency of methicillin-resistant staphylococci (MRS), Pseudomonas, and Enterobacteriaceae from surrounding environment (home, colleges, public transportation system and possessions) in Seoul, and to examine the level of drug resistance to 13 antimicrobial agents, which are in wide spread clinical use in Korea, as well as new agent, tigecycline in Enterobacteriaceae isolates. Of total 239 samples, 18 (7.5%) MRS, 10 (4.2%) Pseudomonas, and 30 (12.6%) Entarobacteriaceae were isolated. A total of 5 (2.1%) methicillin-resistant S. aureus (MRSA) were detected in home (2 samples), colleges (1 sample), and et cetera (2 sample). A total of 5 (2.1%) Escherichia coli were detected in in home (1 samples), public transportations (3 sample), and et cetera (1 sample). Resistance to cephalosporins, fluoroquinolones, carbapenems, ${\beta}$-lactams, tetracyclines, and aminoglycosides was found in 71.9%, 71.9%, 68.8%, 68.8%, 50.0%, and 25.0% of 32 Enterobacteriaceae isolates, respectively. Also, resistance rate to trimethoprim/sulfamethoxazole of the isolates was a 43.8%. Moreover, 59.4% of the isolates were resistant to new agent, tigecycline and resistance to all agents tested was observed in 3 isolates. Five E. coli isolates were resistant to most of the agents tested, but some of them were susceptible to ciprofloxacin and gentamicin. This study can serve as a data point for future comparisons of possible changes in antibiotic resistance levels in surrounding environment. And multilateral strategies for preventing the incidence and spread of antibiotic resistance are needed.