• Journal of Korean Society for Atmospheric Environment
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• v.27 no.5
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• pp.603-613
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• 2011

The collection of $PM_{10}$ and $PM_{2.5}$ samples was made at Gosan site of Jeju Island. Their ionic compositions of both inorganic and organic phases were then analyzed to examine their acidification and neutralization characteristics in atmospheric aerosols. The mass concentrations of $PM_{10}$ and $PM_{2.5}$ at Gosan site were $37.6{\pm}20.1$ and $22.9{\pm}14.3{\mu}g/m^3$, respectively, showing the content ratio of $PM_{2.5}$ to $PM_{10}$ as 61.0%. In the evaluation of ionic balance, the correlation coefficients (r) between the sums of cationic and anionic equivalent concentrations were excellent with 0.982 ($PM_{10}$) and 0.991 ($PM_{2.5}$). The concentration ratios of $PM_{2.5}/PM_{10}$ derived for nss-$SO_4^{2-}$, $NO_3^-$, and $NH_4^+$ were 0.94, 0.56, and 1.02, respectively, indicating the relative dominance of fine fractions. The acidifying capacity of inorganic anions ($SO_4^{2-}$ and $NO_3^-$) in $PM_{10}$ and $PM_{2.5}$ were 96.5% and 97.3%, while those of organic anions ($HCOO^-$ and $CH_3COO^-$) in each fraction were 2.9% and 2.0%, respectively. On the other hand, the neutralizing capacity of $PM_{10}$ and $PM_{2.5}$ by $NH_3$ were 72.8% and 82.3%, while their $CaCO_3$ counter parts were 22.5% and 13.3%, respectively.

• Journal of the East Asian Society of Dietary Life
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• v.26 no.2
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• pp.109-116
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• 2016

The purposes of this study were to analyze the antioxidative effects and antimicrobial activity of Omija. Total phenol contents of Omija extracted with ethanol and water were $53.4{\pm}2.2tannic\;acid\;equivalent/mg$, and $47.9{\pm}2.1tannic\;acid\; equivalent/mg$, respectively. Total flavonoid contents of Omija extracted with ethanol and water were $16.3{\pm}1.1naringin\;equivalent/mg$, and $13.1{\pm}1.4naringin\;equivalent/mg$, respectively. Electron donating ability of ethanol extract ($1,000{\mu}g/mL$) of Omija was $5.1{\pm}0.4%$. This result was lower than the antioxidant vitamin (ascorbic acid: $96.4{\pm}0.6%$) and artificial antioxidant BHT ($70.0{\pm}0.5%$). Nitrite-scavenging abilities of Omija were lower than ascorbic acid and BHT. SOD-like activities of Omija extracts, natural antioxidant, and artificial antioxidant at 5 mg/mL were in the other of ascorbic acid ($99.0{\pm}0.5%$) > BHT ($72.6{\pm}0.5%$) > ethanol extract ($16.3{\pm}0.4%$) > water extract ($14.4{\pm}0.3%$). The order of OH radical scavenging activities of Omija extracts and natural antioxidant at 5 mg/mL was ascorbic acid ($98.9{\pm}0.6%$) > tocopherol ($85.4{\pm}0.6%$) > water extract ($59.1{\pm}0.5%$) > ethanol extract ($33.1{\pm}0.3%$). The results show that the antimicrobial effects of Omija could not be detected at both concentrations and extraction methods.

• Korean Journal of Environment and Ecology
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• v.31 no.1
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• pp.24-29
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• 2017

This study was conducted to identify nesting habits and breeding biology of barn swallow in Gwangju, Korea, for the breeding season 2012 to 2014. All nests were attached to vertical walls and roofs of buildings and situated at mean height $2.9{\pm}0.3m$ above ground with nest diameter $18.2{\pm}3.2cm$, nest depth $9.8{\pm}3.1cm$, nest cup diameter $11.2{\pm}1.5cm$ and nest cup depth $3.27{\pm}0.80cm$. Nests were attached to cemented walls (44.9%), wooden materials (23.1%), bricks (21.8%) and lighting (6.4%). The average clutch size was 4.5 and ranged 2~5. Mean egg length was $18.23{\pm}0.73mm$, breadth $13.11{\pm}0.25mm$, volume $1.60{\pm}0.11cm^3$, shape index $1.39{\pm}0.05$ and weight $1.69{\pm}0.15g$. Hatching and fledgling success rate were 89.1% and 84.5%. Main causes for reproductive failures were unhatched eggs, predation, nest destruction and desertion. These results are expected to be widely used as data for habitat preservation and species management of barn swallows.

• Environmental and Resource Economics Review
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• v.26 no.3
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• pp.417-449
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• 2017

The purpose of this study is to analyze the effect of local area concentration of particulate matter on life satisfaction, by matching subjective satisfaction in the Korea Labor & Income Panel Study data with daily data of $PM_{10}$ and $PM_{2.5}$. We find that the concentration of particulate matter has a significant negative effect on satisfaction. A $1{\mu}g/m^3$ increase in $PM_{10}$($PM_{2.5}$) leads to lower the probability of choosing 'satisfaction' by 0.042%p~0.091%p(0.034%p~0.153%p) and a 1% increase in annual income per household raises the probability of choosing 'satisfaction' by 0.16%p~0.18%p respectively. To estimate the monetary value of reducing $PM_{10}$ and $PM_{2.5}$, we calculate willingness-to-pay for mitigating air pollution, which represents the tradeoff between the reduction in particulate matter and income. We find that people on average are willing to pay \108,787($96)~209,519($186) for a $1{\mu}g/m^3$ reduction in $PM_{10}$ and to pay 89,345($79)~362,930($322) in $PM_{2.5}$. This amount corresponds to 0.26%~0.50%(0.22%~0.88%) of the average annual household income in South Korea.

• Journal of Environmental Health Sciences
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• v.30 no.2
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• pp.140-148
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• 2004

To evaluate the acute effects of fine particles on pulmonary function, a longitudinal study was conducted. This study was carried out for the schoolchildren (3rd and 6th grades) living in Beijing, China. Each child was provided with a mini-Wright peak flow meter and a preformatted health symptom diary for 40 days, and was trained on their proper use. Participants were instructed to perform the peak flow test three times in standing position, three times a day (9 am, 12 pm, and 8 pm), and to record all the readings along with the symptoms (cold, cough, and asthmatic symptoms) experienced on that day. Daily measurement of fine particles (PM$_{10}$ and PM$_{2.5}$) was obtained in the comer of the playground of the participating elementary school for the same period of this longitudinal study. The relationship between daily peak expiratory flow rate (PEFR) and fine particle levels was analyzed using a mixed linear regression models including gender, height, the presence of respiratory symptoms, and daily average temperature and relative humidity as extraneous variables. The total number of students participating in this longitudinal study was 87. The range of daily measured PEFR was 253-501$\ell$/min. In general, the PEFR measured in the morning was lower than the PEFR measured in the evening (or afternoon) on the same day. The daily mean concentrations of PM$_{10}$ and PM$_{2.5}$ over the study period were 180.2$\mu\textrm{g}$/㎥ and 103.2$\mu\textrm{g}$/㎥, respectively. The IQR (inter-quartile range) of PM$_{10}$ and PM$_{2.5}$ were 91.8$\mu\textrm{g}$/㎥ and 58.0$\mu\textrm{g}$/㎥. During the study period, the national ambient air quality standard of 150$\mu\textrm{g}$/㎥ (for PM$_{10}$) was exceeded in 23 days (57.5%). The analysis showed that an increase of 1$\mu\textrm{g}$/㎥ of PM$_{10}$ corresponded to 0.59$\mu\textrm{g}$/㎥ increment of PM$_{2.5}$. Daily mean PEFR was regressed with the 24-hour average PM$_{10}$ (or PM$_{2.5}$) levels, weather information such as air temperature and relative humidity, and individual characteristics including gender, height, and respiratory symptoms. The analysis showed that the increase of fine particle concentrations was negatively associated with the variability in PEFR. The IQR increments of PM$_{10}$ or PM$_{2.5}$ (at 1-day time lag) were also shown to be related with 1.54 $\ell$/min (95% Confidence intervals: 0.94-2.14) and 1.56$\ell$/min (95% CI: 0.95-2.16) decline in PEFR.R.ine in PEFR.ine in PEFR.

• The Korean Journal of Food And Nutrition
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• v.19 no.1
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• pp.70-78
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• 2006

This study was performed to investigate the effect of 12-week weight control program including nutrition education, diet therapy and regular exercise on body weight, obesity degree, BMI and blood lipid levels among middle aged obese women. The 31 middle aged obese women participated in the weight control program for 12-week. The body weight, body composition, blood lipid levels and food habit were measured before and after the weight control program. Changes in body weight after 12 week weight control program showed the slight reduction from $67.4{\pm}10.8kg\;to\;65.1{\pm}9.2kg$. Obesity degree and BMI were decreased from $128.4{\pm}19.1%,\;27.8{\pm}3.9\;to\;123.4{\pm}15.7%,\;26.8{\pm}3.0$, respectively. Waist-hip ratio was also decreased from $0.98{\pm}10.16\;to\;0.94{\pm}0.04$. LBM was also slightly reduced from $39.9{\pm}5.6kg\;to\;37.0{\pm}8.5kg$ with the reduction of body fat. The levels of systolic blood pressure, total cholesterol and triglyceride were slightly decreased, HDL-chol level was significantly increased from $43.1{\pm}14.1mg/dL\;to\;50.4{\pm}16.5mg/dL$. Waist-hip ratio was also slightly decreased after 12 weeks. Food habit score was significantly increased after nutriton education and personal counseling about their eating behaviors and nutritional status.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.10 no.4
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• pp.273-278
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• 2016

Responded threshold level in hearing screening depends on the noise level of test surroundings, physiological characteristics of hearing organs, excessive sound source exposures, and so on. The purpose of this study is to obtain the basic information of hearing threshold level at each frequencies in children with passed hearing screening. Subjects were 110 children, aged were from 3.3 to 16.3 ($9.01{\pm}2.52$), who were at private speech language pathological clinics and daycare centers. Methods of Hearing screening were tympanometry, acoustic reflex threshold, automated otoacoustic emission, and pure tone screening. The subjects were in normal criteria of hearing screening. The differences of hearing threshold among ages and frequencies were measured by means of repeated measures ANOVA. The mean of hearing thresholds level was observed $16{\pm}6.49$, $11.5{\pm}4.79$, $6.86{\pm}4.99$, $5.95{\pm}6.65$ dB HL in the right ear and $15.68{\pm}6.01$, $9.95{\pm}5.24$, $5.72{\pm}5.21$, $5.63{\pm}7.04$ dB HL in the left ear, in frequency of 500, 1,000, 2,000, 4,000 Hz respectively. There was a significant difference between 500 and 1,000, 2,000, 4,000 Hz (p=.000), between 1,000 and 2,000, 4,000 Hz (p=.000).

• 산업보건소식
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• no.48
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• pp.9-18
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• 1987

The results of this study which had been investigated to analyse heavy metal levels and to compare lead, cadmium, copper and zinc concentration in urine of children who lived around the industrial area and the agricultural area. Samples were collected and analyzed from September to December 1986 from 7-9 years old children living in Seoul (4 7 cases), lri ( 64 cases) industrial area and Chinan (56 cases) agricultural area. The summarized results were as follows: 1) The concentrations of lead were Seoul 28.7 $\pm$17.7 ug/l, lri 25.3 $\pm$7.5 ug/l and Chinan 19.3 $\pm$5.2 ug/l 2) The concentrations of cadmium were Seoul 1.5 $\pm$0.8 ug/l, Iri 1.4 $\pm$0.5 ug/l and chinan 0.9 $\pm$0.3 ug/l 3) The concentrations of copper were Seoul 12.8 $\pm$7.0 ug/l, Iri 10.5 $\pm$8.4 ug/l and Chinan 10.0 $\pm$4.5 ug/l 4) The concentrations of zinc were Seoul 383 $\pm$279 ug/l, Iri 329 $\pm$133 ug/l and Chinan 267 $\pm$181 ug/l 5) In lead, cadmium and zinc concentration of children, there were statistical difference between the industrial area and the agricultural area 6) There were no indicated significantly levels by the Sex

• Journal of Ginseng Research
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• v.20 no.3
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• pp.339-343
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• 1996

The effect of ginseng on the reactivity of penile corpus cavernosal smooth muscle strips of rabbits was investigated to support the clinical application of ginseng for the treatment of erectile dysfunction. New Zealand white rabbits were randomly divided into two groups, normal diet group (n=9) and ginseng saponin diet group (n=5). Then, each group was fed normal diet and Korean red ginseng saponin diet (50 mg/kg/day) for 10 weeks. We measured concentration dependent relaxation of corporal smooth muscle to acetylcholine (10-8 M to 10-4M) in organ chamber. The degree of relaxation was expressed as percentage of maximal relaxation obtained by papaverine (10-4M). Dose dependent relaxation of corpus cavernosal smooth muscle to acetylcholine, at the concentration of 10-8 M to 10-4M by half log increment, was 4.06$\pm$0.00, 4.30$\pm$1.30, 5.32$\pm$0.68, 11.64$\pm$1.74, 16.24$\pm$1.61, 23.33$\pm$ 2.29, 26.45$\pm$2.25, 30.43$\pm$2.40 and 33.41 $\pm$2.48 (%), respectively in normal diet group and 9. 83$\pm$4.15, 20.60$\pm$4.62, 24.1815.12, 35.75$\pm$5.71, 43.35$\pm$6.11, 51.30$\pm$6.22, 56.33$\pm$6.22, 54.30$\pm$4.17 and 51.98$\pm$3.92 (Vc), respectively in ginseng group. These data suggest that ginseng enhances ondothelium-dependent acetylcholine-induced relaxation of penile corpus cal.ernosal smooth muscle in rabbits.

• Journal of Preventive Medicine and Public Health
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• v.56 no.5
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• pp.449-457
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• 2023

Objectives: This study investigated the association between baseline exposures to particulate matter with a diameter <2.5 microns (PM_2.5) and subsequent temporal changes in PM_2.5 exposure with the incidence of type 2 diabetes among Royal Thai Army personnel. Methods: A retrospective cohort study was conducted using nationwide health check-up data from 21 325 Thai Army personnel between 2018 and 2021. Multilevel mixed-effects parametric survival statistics were utilized to analyze the relationship between baseline (i.e., PM_2.5-baseline) and subsequent changes (i.e., PM_2.5-change) in PM_2.5 exposure and the occurrence of type 2 diabetes. Hazard ratios (HRs) and 95% confidence intervals (CIs) were employed to assess this association while considering covariates. Results: There was a significant association between both PM_2.5 baseline and PM_2.5-change and the incidence of type 2 diabetes in a dose-response manner. Compared to quartile 1, the HRs for quartiles 2 to 4 of PM_2.5-baseline were 1.11 (95% CI, 0.74 to 1.65), 1.51 (95% CI, 1.00 to 2.28), and 1.77 (95% CI, 1.07 to 2.93), respectively. Similarly, the HRs for quartiles 2 to 4 of PM_2.5-change were 1.41 (95% CI, 1.14 to 1.75), 1.43 (95% CI, 1.13 to 1.81) and 2.40 (95% CI, 1.84 to 3.14), respectively. Conclusions: Our findings contribute to existing evidence regarding the association between short-term and long-term exposure to PM_2.5 and the incidence of diabetes among personnel in the Royal Thai Army.