• 한국실내디자인학회논문집
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• 제25권1호
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• pp.132-141
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• 2016

For those with disabilities, the residential area is the primary place to adapt the disabilities. Since the quality of the area gives a critical impact on their quality of life, it is essential to finding the measures to create the residential environment that supports their independence. In this regard, this study aimed to compare and analyze the interior elements of the houses that hinder the independence of the physically handicapped in the rural and urban areas, and conducted a survey on a total of 80 physically challenged in Seoul and Yeongwol (40 for each area). As a result, the respondents answered that the houses where they are currently living are hindering their independence regardless of area, and there were regional differences in the level of inconvenience with the size of living room, size of utility room, location of room, lighting and heating environment, ventilation system, deteriorated wallpapers and finishing materials, threshold and floor level difference and humidity control. This study has significance by providing the realistic measures to improve the housing environment of the physically challenged living in the rural and urban areas to be customized to them to increase their quality of life.

• Geosystem Engineering
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• 제21권5호
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• pp.282-290
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• 2018

The onset of extreme fire behaviour in a mine drift with longitudinal ventilation was analysed. A fire in a mine drift with continuous fuel load, involving several separate fires may lead to flames tilted horizontally and filling up the entire cross section. This will lead to earlier ignition, higher fire growth rate, higher fire spread rate and a severe fire behaviour. The focus has been on what changes take place at the onset and signs of the impending phenomenon. It was found that the fire gas temperature at the ceiling level provided a poor indicator. At the downstream far-field region of the fire, the sudden temperature increase at the lowest levels of the cross section and the sudden increase in flow velocities would provide signs of extreme fire behaviour. The corresponding full-scale heat release rates of the experiments at the onset of extreme fire behaviour were found to be very high for mining applications but not necessarily for tunnel fires. The heat release rate threshold for a mine drift with smaller cross-sectional dimensions would decrease considerably, increasing the likelihood of occurrence. The distance between the fuel items will play an important role during the initiation of horizontal flames.

• 한국농공학회논문집
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• 제57권6호
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• pp.35-46
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• 2015

Improvement in domestic poultry production has a positive effect on the export competitiveness of the poultry industry. However, overproduction and enlargement of facilities to assure a supply increase a stocking density which make a poor environment in the broiler house. In particular, an intensive rearing environment is vulnerable to dust control that causes respiratory diseases, such as asthma, bronchitis, etc., to farmers and broilers. However, monitoring data and research for environment control are not adequate, and there are no air quality regulations in broiler houses in Korea. In this study, TSP, PM10, inhalable dust and respirable dust concentration were monitored according to season, age of broiler and broiler's activities. Air quality assessment was also performed in accordance with the threshold limit value by Donham et al. (2000). The TSP concentrations were 77.5 %, 219.7 % higher and PM10 concentrations were 121.2 %, 303.8 % higher when change of season and winter respectively than summer. There were significantly different concentrations according to season and age of broiler. Inhalable and respirable dust concentration were also clearly different according to the season and age of broiler. A high dust concentration was observed, specifically exceeding the threshold limit by 119 % in the winter. In the case of the broiler's motion was activity according to worker's access into the broiler house, concentration level was 769.6 % higher than broiler's motion was stable and exceeded the threshold limit. These results suggest that the worker should put on protective equipment to protect there's respiratory health in the broiler house.

• Journal of Preventive Medicine and Public Health
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• 제38권2호
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• pp.141-146
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• 2005

Objectives: Particulate contaminants, such as total and respirable dusts, can harm the health of farm workers via several routes. The principal aims of this field study were to determine the concentrations and emissions of particulate contaminants: total and respirable dusts, in the different types of swine houses used in Korea, and allow objective comparison between Korea and the other countries in terms of swine housing types. Methods: The swine houses investigated in this research were selected with respect to three criteria: the manure removal system, ventilation mode and growth stage of pigs. Measurements of total and respirable dust concentrations and emissions in the swine houses were carried out on 5 housing types at 15 different farm sites per housing type. The swine houses investigated were randomly selected from farms situated within the central districts in Korea: province of Kyung-gi, Chung-buk and Chung-nam. Results: The total and respirable dust concentrations in the swine houses averaged $1.88\;and\;0.64mg/m^3$, ranging from $0.53\;to\;4.37mg/m^3$ and from $0.18\;to\;1.68mg/m^3$, respectively. The highest concentrations of total and respirable dusts were found in the swine houses with deep-litter bed systems: $2.94mg/m^3\;and\;1.14 mg/m^3$, while the lowest concentrations were found in the naturally ventilated buildings with slats: $0.83mg/m^3\;and\;0.24mg/m^3$, respectively (p<0.05). All the swine houses investigated did not exceed the threshold limit values (TLVs) for total ($10mg/m^3$) and respirable ($2.5mg/m^3$) dusts. The mean emissions of total and respirable dusts, per pig (75 kg in terms of live weight) and area ($m^2$), from the swine houses were 97.33 and 9.55 mg/h/pig and $37.14\;and\;12.83mg/h/m^2$, respectively. The swine houses with deep-litter bed systems showed the highest emissions of total and respirable dusts (p<0.05). However, the emissions of total and respirable dusts from the other swine houses were not significantly different (p>0.05). Conclusion: The concentrations and emissions of total and respirable dusts were relatively higher in the swine houses managed with deep-litter bed systems and ventilated naturally of the different swine housing types tested. In further research, more farms than the number used in this research should be investigated, which will present objective and accurate data on the concentrations and emissions of total and respirable dusts in Korean swine houses. In addition, personal sampling should be performed to objectively assess the exposure level of farm workers to particulate contaminants.

• Tuberculosis and Respiratory Diseases
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• 제42권5호
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• pp.737-743
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• 1995

연구배경: 기계호흡을 하고 있는 환자에서 폐렴은 흔히 일어나는 병원 감염이며 사망률도 높은 것으로 알려져 있으나 임상적인 폐렴 진단 기준이나 일반적으로 시행하는 객담의 정성배양법은 폐렴 진단에 오류가 많기 때문에 PSB를 이용한 정량배양법이 진단에 이용되고 있으나, PSB를 쉽게 이용할 수 없는 경우가 있어 비교적 용이하게 이용할 수 있는 EA의 정량배양의 진단적 가치에 대하여 연구하였다. 방법: 72시간 이상 기계호흡을 하고 있는 환자중 임상적으로 폐렴이 의심되는 환자 10명과, 대조군 5명을 대상으로 EA와 PSB를 이용하여 추출한 객담을 정량 배양하였다. 결과: EA와 PSB의 정량배양에서 폐렴의 진단 기준을 각각 $10^5cfu/ml$, $10^3cfu/ml$으로 정할때 PSB에서 민감도 70%, 특이도 80%, 양성예측치 88%, 음정예측치 57%, 정확도 73%, EA에서 민감도 70%, 특이도 60%, 양성예측치 78%, 음성예측치 50%, 정확도 67%였다. 결론: 저자들의 조사결과 기계호흡을 하는 환자의 폐렴진단에서 객담의 정량배양시 cut-off point를 EA에서 $10^5cfu/ml$ 이상 배양된 경우로 정할때, 민감도 70%, 특이도 60%, 양성예측도 78%로서 특이도가 EA 보다 높은 PSB를 대치하지는 못하지만 기관지 내시경을 사용할 수 없는 환자에서 유용하리라고 추측되나 더 많은 연구가 필요하리라 사료된다.

• 한국농공학회논문집
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• 제60권2호
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• pp.75-84
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• 2018

Thermal stress of livestock has been issued due to recent climate change trends and this causes reproductive disorders, decreased feed consumption, immunosuppression, and increased mortality of animals. Concept of THI has been widely used to quantitatively evaluate the degree of thermal stress for animals, however use of this concept is restricted for animals living in the enclosed facilities such as mechanically ventilated broiler houses. In this study, time-based internal energy flow and variation trends of temperature and humidity were analyzed based on BES technique. Local weather data, insulation characteristics of building materials, heat and moisture generation rate from broilers according to age, algorithm of ventilation operation were adopted for boundary condition of the model to accurately compute THI values inside the mechanically ventilated broiler house. From the BES computation, excess frequency of THI threshold in Jeju city was highest on the assumption that air conditioning equipments were not installed. When general raising density ($39kg\;m^{-2}$) was adopted, total 2,191 hours were exceeded. Excess hours of THI threshold were strongly related to the cumulative air temperature ($R^2=0.87$).

• 한국산업보건학회지
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• 제24권4호
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• pp.462-470
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• 2014

Objectives: The purpose of this study was to evaluate quartz concentrations in airborne respirable dust and particle size-related quartz concentrations. Methods: Respirable dust samples were collected using a 10 mm Dorr-Oliver nylon cyclone equipped with a 37 mm, $5{\mu}m$ pore size PVC filter. Dust samples were collected with a Marple's personal cascade impactor from stone grinding operations in five stone-related business located in the Gyeongsangbuk-do area. Results: The geometric mean of quartz concentration in the respirable dust was $0.170mg/m^3$, and the rate of exceeding the Korean Occupational Exposure Limit(KOEL) was 93.3%. The quartz concentration by particle size shows that it was the highest($0.115mg/m^3$) in stage 5($3.50-6.00{\mu}m$), which corresponds with the size of respirable particle. The smaller the particle sizes were, the higher quartz the content became. The mass fractions of inhalable, thoracic, and respirable dust were 72.1%, 36.0%, and 14.4%. Conclusions: The rate of the quartz concentration in respirable dust from stone grinding operations exceeding the American Conference of Governmental Industrial Hygienists Threshold Limit Values was 100%, which means proper work environmental management is required through regular working environmental measurements. Given that the stone grinding operations had a higher small size dust concentrations, there is a need to reduce respirable dust, such as through wet operation and local exhaust ventilation.

• Environmental Analysis Health and Toxicology
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• 제31권
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• pp.11.1-11.6
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• 2016

Objectives A hazard assessment of di(2-ethylhexyl) phthalate (DEHP), a commonly used workplace chemical, was conducted in order to protect the occupational health of workers. A literature review, consisting of both domestic and international references, examined the chemical management system, working environment, level of exposure, and possible associated risks. This information may be utilized in the future to determine appropriate exposure levels in working environments. Methods Hazard assessment was performed using chemical hazard information obtained from international agencies, such as Organization for Economic Cooperation and Development-generated Screening Information Data Set and International Program on Chemical Safety. Information was obtained from surveys conducted by the Minister of Employment and Labor ("Survey on the work environment") and by the Ministry of Environment ("Survey on the circulation amount of chemicals"). Risk was determined according to exposure in workplaces and chemical hazard. Results In 229 workplaces over the country, 831 tons of DEHP have been used as plasticizers, insecticides, and ink solvent. Calculated 50% lethal dose values ranged from 14.2 to 50 g/kg, as determined via acute toxicity testing in rodents. Chronic carcinogenicity tests revealed cases of lung and liver degeneration, shrinkage of the testes, and liver cancer. The no-observed-adverse-effect level and the lowest-observed-adverse-effect level were determined to be 28.9 g/kg and 146.6 g/kg, respectively. The working environment assessment revealed the maximum exposure level to be $0.990mg/m^3$, as compared to the threshold exposure level of $5mg/m^3$. The relative risk of chronic toxicity and reproductive toxicity were 0.264 and 0.330, respectively, while the risk of carcinogenicity was 1.3, which is higher than the accepted safety value of one. Conclusions DEHP was identified as a carcinogen, and may be dangerous even at concentrations lower than the occupational exposure limit. Therefore, we suggest management of working environments, with exposure levels below $5mg/m^3$ and all workers utilizing local exhaust ventilation and respiratory protection when handling DEHP.

• Preventive Nutrition and Food Science
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• 제14권3호
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• pp.173-178
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• 2009

This study was conducted to determine if supplementation with a compound composed of caffeine (50 mg), capsaicin (75 mg), sesamine (30 mg), L-carnitine (300 mg), banaba (50 mg) and lotus (10 mg) enhanced human autonomic nervous activities (ANS) associated with thermogenic sympathetic activity and fat utilization. Ten healthy college males (21.2$\pm$1.0 yr) volunteered for this experiment. Autonomic nervous activities associated with energy metabolism were examined at 30 min intervals for a total of 120-min while at rest and every 5-min during exercise at 50% of the ventilation threshold before and after intake of the compound or placebo with 100 ml of water for 10 days. In addition, heart rate variability power spectral analysis was used to assess human autonomic nervous activities. The results indicated that there were no significant differences in heart rate during rest and exercise among trials. Furthermore, the autonomic nervous activity tended to increase after 10-days of consumption of the test compounds during the experimental period, but the differences did not reach statistical significance. However, before and after the compound test trial there was a significantly higher respiratory gas exchange ratio (rest 0: 0.83$\pm$0.01 vs. rest 3: 0.89$\pm$0.02, p<0.05), carbohydrate oxidation (CHO) rate (rest 0: 44.57$\pm$5.83 vs. rest 2: 63.86$\pm$5.91%, p<0.05) and a lower fat oxidation rate (rest 0: 55.43$\pm$5.83 vs. rest 2: 36.14$\pm$5.91%, p<0.05. In conclusion, the results of the present study suggested that the compound composed of caffeine, capsaicin, sesamine, L-carnitine, banaba and lotus components that was evaluated in this study did not induce a significant increase in human autonomic nervous activities or lipolysis, even though the individual components have been reported to induce increased fat oxidation.

• 한국산업보건학회지
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• 제16권3호
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• pp.193-201
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• 2006

This study was performed to investigate employee exposures to waste anesthetic gases, such as enflurane and sevoflurane in operating rooms of general surgical, children's and dental clinics of a large hospital located in Seoul and to analyze factors affecting the concentrations of waste anesthetic gases. The results of the study are summarized below. 1. Based on results of personal and area samples for airborne enflurane, all of the employees investigated in this study were exposed to airborne enflurane concentrations below the ACGIH-threshold limit value (TLV) of 75 ppm. 2. However, based on results of personal samples for sevoflurane, employees of two (2) out of eleven (11) operating rooms were exposed to sevoflurane concentrations in excess of the NIOSH recommended exposure limit (REL) of 2 ppm. A similar trend was found in the area samples. 3. To investigate the source of sevoflurane emissions, airborne sevoflurane concentrations were measured on an anesthesia machine, a drug cabinet and a desk. It was indicated that the geometric means were 0.93 ppm, 0.83 ppm and 0.72 ppm, respectively. 4. Factors affecting waste anesthetic gas concentrations were the age of anesthesia machine, the volume of operating room and the extent of ventilation (p<0.05). 5. It is recommended that the use of anesthesia equipments be properly controlled, the operating room be well ventilated, and the airborne concentrations of anesthetic gases be continuously monitored.