• Journal of Environmental Impact Assessment
• /
• v.28 no.5
• /
• pp.440-456
• /
• 2019

The controversy of the risk perception related to particulate matters becomes significant. Therefore, in order to understand the nature of the particulate matters, we gathered articles and comments in on-line community related to bicycling which is affected by exposure of the particulate matters. As a result, firstly, the government - led particulate matter policy was strengthened and segmented every period, butthe risk perception related to particulate matters in the bicycle community has become active and serious. Second, as a result of analyzing the perception change of outdoor activities related to particulate matters, bicycle users in community showed a tendency of outdoor activity depending on the degree of particulate matters ratherthan the weather. In addition, the level of the risk perception related to particulate matters has been moved from fears of serious threat in daily life and health, combined with the disregard of domestic particulate matter levels or mask performance. Ultimately, these risk perception related to particulate matters have led some of the bicycling that were mainly enjoyed outdoors to the indoor space. However, in comparison with outdoor bicycling enjoyed by various factors such as scenery, people, and weather, the monotonous indoor bicycling was converted into another type of indoor exercise such as fitness and yoga. In summary, it was derived from mistrust of excessive information or policy provided by the government or local governments. It is considered that environmental policy should be implemented after discussion of risk communication that can reduce the gap between public anxiety and concern so as to cope with the risk perception related to particulate matters. Therefore,this study should be provided as an academic basis for the effective communication direction when decision makers establish the policy related to particulate matters.

• Fashion & Textile Research Journal
• /
• v.16 no.1
• /
• pp.167-174
• /
• 2014

The physical properties of textile materials and thermal physiological responses of the human subjects were evaluated with 4 different types of the army combat uniforms including US, German, Korean and general uniforms for this study. 8 male adults were used as the human subjects and the tests were done in the environmental chamber that was $25{\pm}0.1^{\circ}C$ of temperature, $65{\pm}5%$ of relative humidity and below 0.3 m/sec of air velocity. The test protocol consisted the rest period for 20 min., the exercise period for 20 min., the rest period for 20 min., the exercise period under wind condition for 20 min., and the recovery period for 20 min. The human subjects walked with 4.5 km/hr for 10 min., ran 7.5 km/hr for 10 min. during the first exercise period and walked and ran with the same speeds under 3.5 m/sec of the air velocity that simulated outdoor condition during the second exercise period. The test results of the study were as follows; The wind condition affected the skin and microclimate temperature of the human subjects lower compared to without wind condition, but had insignificant effect on the humidity control. The low air permeability of Korean uniform caused blocking the elimination of the humidity from the body and the regulation of body temperature. However, Korean uniforms could be the excellent one with the designs considering the ventilation of the uniforms and the textile fabrics with better air permeability.

• Journal of Korean Society for Atmospheric Environment
• /
• v.27 no.5
• /
• pp.569-579
• /
• 2011

This study evaluated the indoor air quality of 26 government offices located in Seoul. The pollutant samples were taken from Jan. 13th to Jan. 29th and Feb. 20th to Feb. 23rd, 2010 in the offices. The target indoor pollutants for this study were $PM_{10}$, formaldehyde, carbon monoxide, carbon dioxide, total bacteria counts, total volatile organic compounds, radon, nitrogen dioxide, ozone, and asbestos which were controlled by the indoor air quality law for the multiple-use facilities management. The results of this study showed that some pollutants of the 38.5% offices exceeded the standards of the air quality guideline. The correlation analysis of the same pollutants between indoor and outdoor represented that $NO_2$ (r=0.629, p<0.05) and $O_3$ (r=0.459, p<0.01) were significant, however, $PM_{10}$ and CO were not. The correlation analysis between different pollutants showed that CO and TVOC (total volatile organic compounds: r=0.724; p<0.01), CO and $NO_2$ (r=0.674; p<0.01), HCHO and humidity (r=0.605; p<0.01), $CO_2$ and TVOC (r=0.534; p<0.01), TBC (total bacteria counts) and Asbestos (r=0.520; p<0.01) were significant. The energy-saving system of government buildings in winter caused under-ventilated and poor air quality. This study suggests that the concentrations of radon and $CO_2$ should be used as an indicator for monitoring indoor air quality and maintaining effective ventilations.

• Journal of Preventive Medicine and Public Health
• /
• v.39 no.4
• /
• pp.309-316
• /
• 2006

Objectives: Korean epidemiological studies have used reduced samples according to the subject's characteristics, such as the health services provided, the historical note with asthma, and age, to examine the acute effect of air pollution on asthma using the Korean National Health Insurance records. However, there have been few studies on whether the effects shown in these reduced samples are different from those of all samples. This study compared the effects of air pollution on asthma attacks in three reduced samples with those of entire samples. Methods: The air pollution data for $PM_{10},\;CO,\;SO_2,\;NO_2,\;and\;O_3$, and weather conditions including temperature, relative humidity, and air pressure in Seoul, 2002, were obtained from outdoor monitoring stations in Seoul. The emergency hospital visits with an asthma attack in Seoul, 2002 were extracted from the Korean National Health Insurance records. From these, the reduced samples were created by health service, historical notes with asthma, and age. A case-crossover design was adopted and the acute effects of air pollution on asthma were estimated after adjusting for weather, time trend, and seasonality. The model was applied to each reduced sample and the entire sample. Results: With respect to the health service, the effects on outpatients were similar to those for the total sample but were different for inpatients. These similar effect sizes were also observed in the reduced samples according to the historical note with asthma and age. The relative risks of $PM_{10},\;CO,\;SO_2,\;NO_2,\;and\;O_3$, among the reduced and entire samples were 1.03, 1.04-1.05, 1.02-1.03, 1.04-1.06, and 1.10-1.17, respectively. Conclusions: There was no clear evidence to show a difference between the reduced samples and the entire samples.

• Journal of the Korea Society of Computer and Information
• /
• v.24 no.11
• /
• pp.171-178
• /
• 2019

In this paper, we proposed a plan for a indoor air quality management in elderly care hospital by measuring the indoor air quality level of elderly care hospital and conducting a survey the workers' awareness of indoor air quality. The measurement items were Temperature, Humidity, CO2, CO, PM10, VOC and were taken on April 26, 2019. The survey found that the lower the satisfaction level with indoor air quality, the better outdoor air quality and odor items were analyzed to be the lowest among the indoor environmental factors. When the satisfaction level of indoor air quality is high, the satisfaction level of indoor environment factor is high. The result of the multiple response analysis was "lack of ventilation" and the regression analysis was the lower the "relevance of indoor air quality" category. To provide the best indoor air quality environment for elderly care hospital workers the installation of additional ventilation equipment to remove odors, the increase in the number of natural ventilation and the designation of regular ventilation personnel will be necessary. By establishing such a plan, it is possible to provide indoor air quality environment to provide the best services for elderly care hospital workers.

• Clean Technology
• /
• v.26 no.1
• /
• pp.13-21
• /
• 2020

Air pollutants in a subway are complexly caused by outdoor factors such as ventilating opening and indoor factors such as the movement of passengers on the subway. According to recent research results, most of the air pollutants generated in subway tunnels and stations are caused by indoor variables such as train movement. To control air pollutants such as particulate matter (PM), a prevention facility such as the electrostatic precipitator (EP) or bag filter collector was required in a subway station. In particular, the PM removed by the EP must be kept clean continuously to manage PM effectively. Therefore, a nano-bubbling washing system was developed in this study to clean a contaminated collecting plate in an EP at the main subway tunnel in Seoul. Removal efficiency compared with normal water and nano-bubbling water was likewise studied. As a result, the washing efficiency of collective PM increased in accordance with the increasing of injection pressure, with nano bubbling washing being 130.8% higher than tap water. According to increase in washing times, the maximum washing efficiency was 143.1% higher than tap water, but suitable washing times were less than 3 times. According to the results of the washing efficiency by variation of residence time, it was confirmed that the maximum residence time of nano-bubble water was maintained within 5 minutes.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.26 no.3
• /
• pp.324-333
• /
• 2016

Objectives: We aimed to compare the sampling performance of different flow-based impactor samplers for collecting fungal spores and bacteria and to explore the association of the level of bioaerosols with activity patterns of occupants in daycare center settings. Methods: For comparison of sampling performance, two different flow-based samplers (greater than 100 L/min or not) were selected; a low flow-based sampler (one-stage Andersen sampler) and two high flow-based samplers (DUO SAS SUPER 360 sampler, BUCK bio-culture sampler). We collected airborne mold and bacteria in 30 daycare centers with various levels of contaminated air. Three repeat samplings per each sampler were performed. Mold and bacteria were grown for 96 hours at $25{\pm}1^{\circ}C$ and 48 hours at $35{\pm}1^{\circ}C$, respectively. The Andersen and SAS samplers were used for investigating the association between the level of bioaerosols and the activity patterns of occupants in daycares. Particular matters 10($PM_{10}$), temperature, and relative humidity were monitored as well. Samplings were carried out with one-hour interval from 9 to 5 O'clock. For statistical comparisons, Kruskal-Wallis test, Wilcoxon's signed rank test, and multiple regression analysis were carried out. Results: The airborne level of molds by the low flow-based sampler were significantly higher than that of high flow-based samplers (indoor, P=0.037; outdoor, P=0.041). However, no statistical difference was observed in the airborne level of bacteria by each sampler. Also the level of bioaerosols varied by the time, particularly with different activity patterns in daycare centers. The higher level of mold and bacteria were observed in play time in indoor. Similarly, the concentrations of $PM_{10}$ were significantly associated with the level of bioaerosols (P<0.05). Conclusions: Our findings indicate that the flow rate of sampler, rather than total air volume, could be able to affect the results of sampling. Also, the level of airborne mold and bacteria vary behavior patterns of occupants in indoor of daycare settings. Therefore, different samplers with other flow rate may be selected for mold or bacteria sampling, and activity patterns should be considered for bioaerosol sampling as well.

• Nutrition Research and Practice
• /
• v.9 no.2
• /
• pp.158-164
• /
• 2015

BACKGROUND/OBJECTIVES: Vitamin D deficiency is common in hemodialysis patients. The aim of this study was to identify whether or not sun exposure and dietary vitamin D intake have effects on serum 25-hydroxyvitamin D (25(OH)D) status in hemodialysis (HD) patients. The objective was to identify the main determinants of serum vitamin D status in the study subjects. SUBJECTS/METHODS: A cross-sectional study of 47 HD patients (19 males and 28 females) was performed. We assessed serum 25(OH)D and $1,25(OH)_2D$ levels between August and September 2012 and analyzed the prevalence of vitamin D deficiency in HD patients. To evaluate the determinants of serum 25(OH)D levels, we surveyed dietary vitamin D intake, degree of sun exposure, and outdoor activities. To compare biological variables, serum 25(OH)D was stratified as below 15 ng/ml or above 15 ng/ml. RESULTS: Mean 25(OH)D and $1,25(OH)_2D$ levels were $13.5{\pm}5.8ng/ml$ and $20.6{\pm}11.8pg/ml$, respectively. The proportions of serum 25(OH)D deficiency (< 15 ng/ml), insufficiency (15-< 30 ng/ml), and sufficiency (${\geq}30ng/ml$) in subjects were 72.4%, 23.4%, and 4.3%, respectively. Prevalence of vitamin D deficiency in female patients was 78.6%, whereas that in males was 63.2% (P = 0.046). Vitamin D intake and sun exposure time were not significantly different between the two stratified serum 25(OH)D levels. Dietary intake of vitamin D did not contribute to increased serum 25(OH)D levels in HD patients. The main effective factors affecting serum 25(OH)D status were found to be the sun exposure and active outdoor exercise. CONCLUSIONS: Hypovitaminosis D is common in HD patients and is higher in females than in males. Sun exposure is the most important determinant of serum 25(OH)D status in HD patients.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.24 no.4
• /
• pp.453-461
• /
• 2014

Objective: Based on the fact that fine particles are more likely to produce negative influences on the health of occupants as well as the quality of indoor air compared to coarse particles, it is critical to determine concentrations of aerosol particles with different sizes. Thus, this study focused on the size distribution and concentrations of aerosol particles in university buildings. Method: Aerosol particles in indoor air were collected from four areas: corridors in buildings(In-CO), lecture rooms(In-RO), laboratories(In-LR), and a cafeteria(In-RE). Samples were also collected from outside for comparison between the concentrations of indoor and outdoor particles. For the collection of the samples, an eight stage non-viable cascade impactor was used. Result: The average concentration of $PM_{10}$ in the samples collected from indoor areas was $34.65-91.08{\mu}g/m^3$,and the average for $PM_{2.5}$ was $22.65-60.40{\mu}g/m^3$. The concentrations of the aerosol particles in the corridors, lecture rooms, and laboratories were relatively higher than the concentrations collected from other areas. Furthermore, in terms of mass median aerodynamic diameter(MMAD), the corridors and lecture rooms had higher numbers due to their characteristics, showing $2.36{\mu}m$ and $2.11{\mu}m$, respectively. Laboratories running an electrolysis experiment showed $1.58{\mu}m$, and the cafeteria with regular maintenance and ventilation had $1.96{\mu}m$. Conclusion: The results showed that the $PM_{10}$ concentrations of all samples did not exceed indoor air quality standards. However, the $PM_{2.5}$ concentration was over the standard and, in particular, the concentration of fine particles collected from the laboratories was relatively higher, which could be an issue for the occupants. Therefore, it is important to improve the quality of the indoor air in university buildings.

• Asian-Australasian Journal of Animal Sciences
• /
• v.30 no.5
• /
• pp.749-754
• /
• 2017

Objective: The objective of the present study was to investigate the effects of farrowing month (FM), parity and sex on the growth performance of Berkshire swine raised in alternative production systems. Methods: A total of 40 farrowing records from 27 sows and 1,258 body weight (BW) records from 274 piglets collected over a two-year period were used for the analysis. The BWs were recorded at birth, weaning (28 d), 56, 84, 112, and 140 days. Any BW not recorded on schedule was recalculated to conform the days of age among corresponding BW records, using growth curves drawn with polynomial functions whose power was determined by the number of existing observations for each individual. Results: The mean parity (${\pm}$standard deviation) of the sows was $3.42{\pm}2.14$. The sows that farrowed in June had the lowest number of total born with an average of $6.25{\pm}2.22$ piglets per sow. However, the lowest average number of piglets weaned at day 28 was found in sows that farrowed in May, as well as the highest number recorded for the stillborn piglets with an average of 2.67 piglets per sow. Moreover, the smallest increase in weight from birth to weaning occurred in piglets that were farrowed in May, which also corresponds with the average daily gain (ADG) of 0.29 kg and the last recorded weight measurement on day 140 of $41.69{\pm}1.45kg$. Contrastingly, the highest growth rate was found among pigs farrowed in June, with the largest increase in weight of 7.55 kg from birth to weaning, the highest ADG of 0.51 kg from birth to 140 day of age and the highest BW of $74.70{\pm}1.86kg$ recorded on day 140. Conclusion: Pigs farrowed in June also had the least number of piglets that died between birth and weaning. The zone of thermal comfort found in sows reared in indoor confinement systems did not improve the reproductive performance of the sows reared in an outdoor, alternative production system, while the growth performance of the piglets was improved when the ambient temperature was consistently hot or consistently cold.