• 한국산업보건학회지
• /
• 제15권1호
• /
• pp.71-81
• /
• 2005

The purposes of this study was to collect, analyze, and describe the MF exposure levels from subways in Korea and to measure and evaluate the MF levels generated from electric appliances used at general homes. The target subway lines were Seoul Metropolitan Line 1 to Line 8, Bundang Line, Incheon Line, Daegu Line, Gwangju Line, and Busan Line 1 and Line 2. We measured at each station in those subway lines and, all the train types (pantograph-equipped, motor-equipped, and common), and platform types(facing and isolating) were investigated by the distance(80, 200, 400 cm) from the train on 19 targeted subway lines using 3 magnetic field measuring devices (EMDEXII, Enertech Co.) during the survey from January till October, 2004. On the other hand, the levels of the 60Hz magnetic fields generated from 14 items of home electric appliances such as electric blankets, hair dryers, electric razors, etc. were measured at 10 general homes using 5 EMDEXII meters with a sampling interval of 1.5 second by the distance(surface, 30, 50, 100, 300cm ) from the target electric appliances. The survey results in the whole subway lines examined in this study were as follows; Seoul Metropolitan Line 4 using AC(alternating current) power source showed the highest mean value of $2.85{\mu}T$, followed by Seoul Metropolitan Line 1 running between Seoul and Incheon using AC($2.78{\mu}T$), Seoul Metropolitan Line 1 between Seoul and Uijongbu using AC($2.73{\mu}T$), Bundang Line using AC($1.79{\mu}T$), Seoul Metropolitan Line 1 connected from Yongsan using AC($1.67{\mu}T$), Seoul Metropolitan Line 1 between Seoul and Suwon using AC($0.79{\mu}T$), and so on. In general, the intensity of the magnetic field in the subway systems in Korea was significantly higher when using AC($2.14{\pm}0.91{\mu}T$) than when using DC($0.29{\pm}0.44{\mu}T$) power source. Among the home electric appliances examined, microwave ovens showed the highest mean value of $7.69{\mu}T$, followed by hair dryers($6.47{\mu}T$), vacuum cleaners($5.27{\mu}T$), televisions ($2.26{\mu}T$), electric blankets($1.38{\mu}T$), personal computers ($0.81{\mu}T$), and so on. Two items of electric appliances showed the excess value of $0.2{\mu}T$ at the distance of 30cm in the MF exposure level; electric razors $1.58{\pm}2.13{\mu}T$ and vacuum cleaners $0.48{\pm}0.44{\mu}T$. As a whole, this study showed a tendency that the shift of the MF levels according to the increase of distance from the electric appliances was lower than those of the results surveyed in UK and USA. As a result, this study is expected to suggest meaningful data for the future study in exposure assessment of magnetic fields and for the establishment of guidelines for subways and electric appliances in Korea. More detailed and large scaled exposure assessment studies should be performed continuously to get the various and useful information on health risk assessment of MFs in Korea.

• 한국치위생학회지
• /
• 제11권5호
• /
• pp.685-693
• /
• 2011

Objectives : Five years have passed since the departments of dental hygiene with four-year term released their graduates. It is necessary to investigate concordance between desired career and current job and job satisfaction in dental hygienists according to graduation term. Accordingly, a survey on concordance between desired career and current job and job satisfaction in dental hygienists according to graduation term was conducted to obtain a basis necessary for providing right job consciousness to students of departments of dental hygiene. Methods : Of departments of dental hygiene nationwide, a total of four departments consisting of two departments with 3-year term and two departments with 4-year term were randomly selected. Of 683 graduates for 2006-10 of the selected departments, 163 graduates who agreed to participate in this study through telephone and e-mail were chosen as subjects. The data of 159 graduates were analyzed except for 4 graduates who did not respond to job satisfaction. The questionnaire consisted of a total of 17 questions: 5 general questions such as graduation term, and current job and salary, 2 questions for desired career at the time of entrance and graduation, and 10 questions for the satisfaction of current job and working environments. Concordance between the desired career at the time of entrance and graduation and current job was calculated using Kappa-value. A cross analysis was conducted to investigate job satisfaction according to general features and graduation term. A statistical significance was examined using $X^2$-test (p<0.05). Results : The Kappa-value for concordance between the desired career at the time of graduation and the current job was 0.288, showing slightly low concordance. In particular, the Kappa-value was 0.089 in the graduates of departments of dental hygiene with 3-year term, which showed significantly low concordance. The job satisfaction of the graduates was 49.1%, which was higher in the graduates with 4-year term than in the graduates with 3-year term, but was statistically insignificant (p>0.05). The detailed job satisfaction was all higher in the graduates with 4-year term than in the graduates with 3-year term except for distance to a working place, but a statistical significance was only found in working place recognition and regional status (p<0.05 ). Conclusions : This study showed differences in concordance between desired career and current job and job satisfaction between the graduates of departments of dental hygiene with 3-year term and the graduates of departments of dental hygiene with 4-year term. Therefore, the curriculum of department of dental hygiene is required to be more specifically applied in accordance with graduation term. In addition, a further study is required to develop specialized curriculums in accordance with graduation term.

• 한국전통조경학회지
• /
• 제29권2호
• /
• pp.118-129
• /
• 2011

본 연구는 일제강점기에 조영된 용산 총독관저와 그 정원에 관한 연구이다. 네오바로크풍의 건물과 정원이 계획되었는데, 이때 작성된 설계도면은 기존과는 달리 정원에 관한 다양한 정보를 포함하고 있다. 이러한 용산 총독관저 정원설계도면의 해석과 신문기사 관련 문헌을 통한 분석으로 도출한 조경사적 가치는 다음과 같다. 첫째, 용산 총독관저 정원이 근대시기에 조영된 최초의 서양식 정원으로서의 가능성이다. 건물과 함께 정원이 1909년에 완성되어 1911년 조영된 덕수궁 석조전 정원보다 시기적으로 앞선다. 둘째, 당시 근대건축과 함께 도입된 정원 양식과 정원 구성요소를 알 수 있다. 건물의 중심과 정원 진입부의 기념비가 연결된 중심축을 기준으로 정원구성요소가 배치되었는데, 시각적 중심이 되는 비스타(Vista)를 이루는 기념비, 바로크 정원에서 보이는 화단 형태, 축과 대칭으로 배치된 수공간, 화단 형태와 축을 강조한 배식 패턴이 이에 해당한다. 셋째, 서양정원문화의 전파이다. 서양식 문화인 가든파티 형식의 원유회가 열렸으며, 관저에서는 저녁시간대에 만찬과 의전 행사를 진행하였다. 넷째, 근대 조경도면으로의 사료적 가치이다. 도입 수종과 배식 패턴을 구분한 최초의 근대 조경도면으로 기존의 간략한 수목 심벌 또는 화단 형태의 표기에서 진일보한 표현이다. 부차적으로 지형 변형을 위한 현재 표고와 계획고, 수경요소의 배관, 상세 단면 등이 표기되어 있다. 향후 근대조경의 실질적인 분석을 위해서 새로운 사료의 발굴과 분석으로 근대조경에 대한 연구의 폭이 확대되길 바라는 바이다.

• Journal of Preventive Medicine and Public Health
• /
• 제49권4호
• /
• pp.205-219
• /
• 2016

Objectives: No children-specified review and meta-analysis paper about the short-term effect of fine particulate matter ($PM_{2.5}$) on hospital admissions and emergency department visits for asthma has been published. We calculated more precise pooled effect estimates on this topic and evaluated the variation in effect size according to the differences in study characteristics not considered in previous studies. Methods: Two authors each independently searched PubMed and EMBASE for relevant studies in March, 2016. We conducted random effect meta-analyses and mixed-effect meta-regression analyses using retrieved summary effect estimates and 95% confidence intervals (CIs) and some characteristics of selected studies. The Egger's test and funnel plot were used to check publication bias. All analyses were done using R version 3.1.3. Results: We ultimately retrieved 26 time-series and case-crossover design studies about the short-term effect of $PM_{2.5}$ on children's hospital admissions and emergency department visits for asthma. In the primary meta-analysis, children's hospital admissions and emergency department visits for asthma were positively associated with a short-term $10{\mu}g/m^3$ increase in $PM_{2.5}$ (relative risk, 1.048; 95% CI, 1.028 to 1.067; $I^2=95.7%$). We also found different effect coefficients by region; the value in Asia was estimated to be lower than in North America or Europe. Conclusions: We strengthened the evidence on the short-term effect of $PM_{2.5}$ on children's hospital admissions and emergency department visits for asthma. Further studies from other regions outside North America and Europe regions are needed for more generalizable evidence.

• 한국조리학회지
• /
• 제19권1호
• /
• pp.179-188
• /
• 2013

본 연구는 고아미로 만든 약과의 품질특성을 알아보고자 하였다. 밀가루에 고아미를 비율별로 첨가하여(100, 80:20, 60:40, 40:60, 20:80, 100) 약과를 만들고 집청전 후 무게, 경도, 수분 함량, 색도, 관능검사를 실시하였다(약과 반죽 14g: 12mm 몰드에 성형, 구운 온도: $160^{\circ}C$, 20Min., 집청: $60^{\circ}C$, 30Min.). 밀가루로 만든 약과의 집청전후의 무게가 가장 가벼웠고, 고아미의 첨가량이 증가할수록 약과의 무게가 유의적으로 무거웠다. 약과의 부피는 밀가루약과의 부피가 가장 컸고 고아미의 첨가량이 증가할수록 약과의 부피가 유의적으로 작아졌다. 수분 함량은 고아미 100%로만 만든 약과가 가장 컸다. 약과의 경도는 고아미를 첨가한 약과가 높았고, 씹힘성은 경도가 가장 낮은 밀가루로 만든 약과인 대조군이 가장 낮았고, 부착성과 탄력성, 검성과 응집성은 유의적인 차이를 보이지 않았다. 약과의 명도는 고아미의 첨가량이 증가할수록 낮아졌고, 적색도와 황색도는 고아미의 첨가량이 증가할수록 높아졌다. 고아미약과의 관능검사 결과 밀가루와 고아미가 비율별로 섞인 약과보다 오히려 밀가루만으로 만든 대조군이나 고아미만으로 만든 약과의 선호가 높았다. 또한 고아미 첨가량이 증가할수록 약과의 단맛이 강하고 촉촉하여 높게 선호되었다. 따라서 본 연구결과 밀가루를 대신하여 고아미쌀 만으로도 촉촉하고 팽화율이 비교적 높은 품질이 좋은 약과의 개발이 가능함을 알 수 있었다.

• 한국산업보건학회지
• /
• 제16권4호
• /
• pp.324-333
• /
• 2006

This study was designed to investigate the effect of bone demineralization and tibia lead on blood lead in retired lead workers. Two hundred thirty five(126 females and 109 males) retired lead workers who worked in 4 different lead factories and 101 non-occupationally lead exposed subjects(51 females and 51 males) were recruited from March 2004 to October 2004. Bone mineral density(BMD) was measured at left calcaneous bone area by broadband ultrasound attenuation(BUA) method with QUS-2(Metra Biosystems Inc, USA). The BUA value transformed into T-score by WHO standard conversion criteria. Tibia bone lead was measured for skeletal bone lead with K-xray fluorescence(K-XRF) and blood lead was analyzed with flameless atomic spectrophotometer. Hemoglobin, hematocrit, serum calcium and iron were also analyzed. In addition, information for smoking and drinking status and basic personal data such as age, gender and lead exposure were also collected using questionnaire inquiry. Blood lead was correlated with tibia lead (r=0.664) and these two variables were negatively correlated with BMD in bivariate analysis. BMD showed significant main effect on the change of blood lead independent to tibia lead without any effect modification of age or gender; the one T-score unit decrease of mineral bone density made $0.43{\mu}g/dl$ increase of blood lead. On the other hand, tibia lead showed effect modification with gender on blood lead; the slope of tibia lead on blood lead in male was steeper than in female and crossed at around zero of tibia lead. In the multiple regression analysis of blood lead and tibia lead on BMD after adjustment of related covariates, only blood lead showed statistically significant effect on BMD. This study confirmed that BMD and blood lead were significantly associated. To verify the causal association of BMD on blood lead and vice versa, further longitudinal studies are needed.

• 한국산업보건학회지
• /
• 제17권1호
• /
• pp.43-52
• /
• 2007

This study was designed to investigate the difference of airborne lead concentration by type of lead industries and type of lead exposure and to evaluate their association with lead biomarkers of lead workers in 11 lead using industries. Total of 182 lead workers (male: 167, female: 15) from 11 lead industries were participated for this study from March, 2004 to August, 2005. Airborne lead concentration were measured by representative personal sampling of workers in each unit workplace and applied same concentration value to the workers in the same unit workplace who did not measure their airborne lead with personal air sampling. Tibia lead, blood lead, zinc protoporphyrin in whole blood, ${\delta}$-aminolevulinic acid in urine, hemoglobin and hematocrit were selected as study variables of indices of lead exposure. Information about type of lead exposure (fume or non-fume other), age, work duration, smoking & drinking habit were also collected. Significant differences were seen in the means of zinc protoporphyrin, blood lead and tibia lead in lead workers by different airborne lead concentration in workplace. While blood lead and tibia lead in lead workers were significantly higher in secondary smelting than other types of lead industries, zinc protoporphyrin, ${\delta}$-aminolevulinic acid in urine and airborne lead concentration were significantly higher in litharge manufacturing. While the mean blood lead was significantly higher in the lead workers working in fume type unit workplace than those of non-fume lead workers, the mean airborne lead concentration of fume workers was significantly lower than non-fume lead workers. In the multiple regression analysis of airborne lead concentration and the type of lead exposure on tibia lead and lead exposure indices after adjustment of related covariates, airborne lead concentration was statistically significantly associated with blood lead and tibia lead, but the type of lead exposure was only associated with blood lead. To verify the causal association of airborne lead concentration on blood lead and tibia lead, further studies are needed.

• 한국환경보건학회지
• /
• 제37권6호
• /
• pp.450-459
• /
• 2011

Objectives: Biomarkers in urine are important in assessing exposures to environmental or occupational chemicals and for evaluateing renal function by exposure from these chemicals. Spot urine samples are needed to adjust the concentration of these biomarkers for variations in urine dilution. This study was conducted to evaluate the suitability of adjusting the urinary concentration of cadmium (uCd) and arsenic (uAs) by specific gravity (SG) and urine creatinine (uCr). Methods: We measured the concentrations of blood cadmium (bCd), uCd, uAs, uCr, SG and N-acetyl-${\beta}$-D-glucosaminidase (NAG) activity, which is a sensitive marker of tubular damage by low dose Cd exposure, in spot urine samples collected from 536 individuals. The value of uCd, uAs and NAG were adjusted by SG and uCr. Results: The uCr levels were affected by gender (p < 0.01) and muscle mass (p < 0.01), while SG levels were affected by gender (p < 0.05). Unadjusted uCd and uAs were correlated with SG (uCd: r = 0.365, p < 0.01; uAs: r = 0.488, p < 0.01), uCr (uCd: r = 0.399, p < 0.01; uAs: r = 0.484, p < 0.01). uCd and uAs adjusted by SG were still correlated with SG (uCd: r = 0.360, p < 0.01, uAs: r = 0.483, p < 0.01). uCd and uAs adjusted by uCr and modified uCr ($M_{Cr}$) led to a significant negative correlation with uCr (uCd: r = -0.367, p < 0.01; uAs: r = -0.319, p < 0.01) and $M_{Cr}$ (uCd: r = -0.292, p < 0.01; uAs: r = -0.206, p < 0.01). However, uCd and uAs adjusted by conventional SG ($C_{SG}$) were disappeared from these urinary dilution effects (uCd: r = -0.081; uAs: r = 0.077). Conclusions: $C_{SG}$ adjustment appears to be more appropriate for variations in cadmium and arsenic in spot urine.

• 한국산업보건학회지
• /
• 제11권1호
• /
• pp.34-41
• /
• 2001

Passive samplers have been used for personal, indoor, and outdoor air monitoring of VOCs at ppb concentrations in community and office environments. The path length of modified passive sampler was shortened, so it was intended to increase an uptake rate. The performance of the modified 3M 3500 organic vapor monitor(OVM) as a tool for assessing exposures to toxic air pollutants in nonoccupational community environments was evaluated using combined controlled test atmospheres of six selected target volatile organic compounds(VOCs): benzene, methyl tert-butyl ether(MTBE), chloroform, 1,4-dichlorobenzene, tetrachloroethylene, and toluene. The experiments were conducted by exposing the dosimeters to concentrations of $50{\sim}100{\mu}g/m^3$ on six face velocity(0.00, 0.02, 0.06, 0.12, 0.20, 0.30 m/sec) for 24 hours. If the uptake rate was increased, that means that we could use the passive sampler more effectively. The uptake rates were increased linearly according to reduce the path length. Although the diffusion path length was shortened, the change of uptake rate was within ${\pm}25%$ of theoretical value, indicating that the modified passive sampler(TM) can be effectively used over the range of concentrations and environmental conditions tested with a 24-h sampling period if the face velocities were over 0.12 m/s for 6 components of VOCs. But when the face velocities were less than 0.12 m/s, uptake rates were reduced more than expected values. So, the passive sampler with the shortened path length should be used at indoor or outdoor environment where the face velocity should be over about 0.10 m/s. If the path length was shortened more, the uptake rate was more effected by starvation.

• 한국산업보건학회지
• /
• 제3권1호
• /
• pp.22-36
• /
• 1993

This study was conducted to evaluate the charcoal tube sampling method for carbon disulfide in the air. Breakthrough was investigated according to flow rate, sampling time and air volume. Also the storage stability by storage method and time was investigated. The results are summarized as follows. 1. The samples stored at room temperature($28.2^{\circ}C$), refrigerator($3.8^{\circ}C$) and freezer($-15.6^{\circ}C$) were analyzed every week to five weeks. At one week storage at room temperature, 3.5% of $CS_2$ in the front section of the charcoal tube migrated into the back section and 57.7% at five weeks. The amount of $CS_2$ in the back section of the charcoal increased continuously by storage time. Migration of $CS_2$ was slow at refrigerator, and stopped occur at freezer. Recovery rate $CS_2$ was 52-82% at room temperature and 92-101% at refrigerator, based on the amount at freezer as a reference value. Thus loss was observed at room temperature. 2. When 6-48 L of fresh air were passed through tubes with spiked amounts of 0.379 and 0.759mg sample, the amounts of $CS_2$ in the back section of charcoal were 5.7-132.4 and 0-92% of the amount in the front section, respectively. The total recovery rates of$CS_2$ from 0.379 and 0.759mg spiked sample were 35.7-101.0% and 9l.3-100.1%, respectively. $CS_2$ loss was observed in 0.379mg spiked sample, but not in 0.759mg spiked sample. In the spiked samples, the amount of $CS_2$ in the back section of charcoal was not affected by flow rate when the air volume was controlled. The amount of $CS_2$ in the back section of charcoal increased over sampling time. And the faster the flow rate, the more the migration amount when the sampling time was the same. 3. A known concentration, 10 ppm of $CS_2$, was produced in a 200 L Tedlar bag. When the air volume was 24, 36, 48 L, breakthrough was 5.8, 16.9, 47.4%, respectively. The sampling flow rate of 0.05, 0.1, 0.2 Lpm did not change the breakthrough rate. Breakthrough increased over sampling time. And the faster the flow rate, the more the breakthrough, when the sampling time was the same.