• Particle and aerosol research
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• v.12 no.3
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• pp.95-102
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• 2016

Controlling exposures to occupational hazards is important for protecting workers. Certified facepiece respirators are recommended when engineering controls do not adequately prevent exposures to airborne nanomaterials. The objective of this study is to carry out the experimental performance test to investigate the fractional efficiencies of the filter media for two grades of facepiece respirators. Experimental performance evaluations were carried out for the test NaCl particles and silver nanoparticles. For media of respirator filter, the penetration of NaCl particles was less than 5% and the most penetrating particle size occurred at about 40 nm. For silver nanoparticles, the most penetrating particle size was about 20nm with higher efficiency than those of NaCl particles. Charge characteristics of airborne nanoparticles is important because the media of respirator filter is made by the electret filter media.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.30 no.2
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• pp.109-123
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• 2020

Objectives: The aims of this study were to review the standards and key components of the standards for disposable masks in Korea, the US, EU, Japan, and China and to evaluate the appropriateness of disposable masks during a virus pandemic. Methods: We reviewed the standards in the above countries and compared their key elements for each standard. For the second purpose, systemic paper gathering using key words like 'mask', 'respirator' 'virus', and 'coronavirus' in the PubMed search engine was performed. Fifty-three papers were selected and reviewed in regard to the appropriateness of test protocols with sodium chloride(NaCl) particles for virus filtration and the effectiveness against viruses. Results: The standards for masks are largely divided into two categories: US standards and EU standards. In Korea, the Ministry of Employment and Labor adapted the EU standards for workers and the Health Masks adopted the Ministry of Employment and Labor standards by the Ministry of Food and Drug Safety. Regarding airborne viral infections, WHO emphasizes only droplet infection, while many studies have shown that small particles enter the air through coughing or sneezing, which increases the possibility of airborne infection. Compared to other particles, various factors such as airborne viability and the ability to replicate the virus in the body are further involved in the virus's airborne infection rate. Airborne infection is classified into absolute air infection, preferential air infection, and opportunistic air infection. The NaCl-certified N95 mask showed good filtration efficiency against viruses and NaCl particles were proved to be a surrogate material for viruses. From this, KF94 is also expected to be effective in blocking viruses. Conclusion: The N95 test method could be used as a surrogate test method for virus filtration. N95-class masks have been found to effectively block viral infections in the air. However, surgical or medical masks are only partially effective against airborne virus infection though they could effectively block large droplet infection. However, most studies considered in this study targeted N95 in foreign countries and studies on masks actually used in Korea are very limited, so studies on microorganisms and reuse on domestic masks should be conducted in the future.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.2
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• pp.247-264
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• 2023

Objectives: The study was to examine the features of three-dimensional(3D) face dimensions and to develop fit test panels for the labor population using respirators in South Korea. Methods: This study was part of the first-year work of a two-year-project conducted at Occupational Safety and Health Research Institute in 2021. After 3D head dimensions data were collected from Size Korea Center managing Sixth Size Korea databases, 3D face dimensions DB for the South Korean labor population was established for 21 items of face dimensions in line with the ISO/TS 16976-2 and KS A ISO 15535. With the South Korean labor population 3D face dimensions DB, in accordance with the ISO/TS 16976-2, the descriptive statistics of 3D face dimensions were calculated and two fit test panels were developed. Results: A total of 2,752 subjects were finally determined and they were 52.9% for male, 41.2% for the highest age-group of 15-29, and residents in the capital area. Mean and standard deviation were obtained for each of the 21 3D face dimensions items for the South Korean labor population. Among the items, male and female face widths were 137.6±5.7 mm, 133.2±5.0 mm, respectively. Male and female face lengths were 116.6±7.0 mm, 107.8±6.8 mm, respectively. Two new South Korean fit test panels, a bivariate test panel and a principal component analysis test panel, were developed using the 3D face dimensions DB as well. Conclusions: Using the 3D face dimensions DB, the mean and standard deviation were featured for each of the 21 items and also the two fit test panels were newly developed in the study. It is suggested that the study outputs should be utilized practically and effectively in selection, use, and management of respirators at work, expecting that respiratory protection can be furthermore improved for respirator users including labor population across the country.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.3
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• pp.177-183
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• 2013

Objectives: 본 연구는 호흡보호구의 밀착도의 척도인 밀착계수 (FF)를 이용하여마스크에 마스크 커버를 씌웠을 때 호흡보호구의 밀착에 어떠한 영향을 미치는지 평가하고자 하였다. Methods: 3개 회사의 호흡보호구 (1개 1/4형, 2개 반면형)를 선정하여25의 피검자 (남자 16, 여자 9)에게 마스크 커버를 씌우지 않은 마스크와 씌운 마스크를 착용하게 하고 정량적인 밀착도 검사 (QNFT)를 실시하여 밀착계수 (FF)를 측정하였다. 동일한 조건에서 각 피검자에게 3번의 QNFT를 실시였으므로 한 마스크 당 씌운 것 75회, 씌우지 않은 것 75회, 150회를 시행하여 비교하였고 3개 마스크에 총 450회를 시행하였다. Results: 마스크 A (반면형)는 예상과는 다르게 마스크 커버가 있는 경우가 없는 경우보다 FF값이 더 높게 나왔으며 (p<0.05), 마스크 B (1/4형)와 마스크 C (반면형)은 마스크 커버가 없는 경우가 있는 경우보다 FF가 높게 나왔다. 마스크 B는 마스크 커버와 관계없이 FF가 너무 낮아 밀착에 문제가 있다고 판단되었으며 반대로 마스크 C는 마스크 커버에 영향을 받았으나 FF가 매우 높게 나와 밀착에는 큰 문제가 없다고 판단되었다. Conclusions: 본 연구 결과는 마스크에 자신의 마스크 커버를 씌울 경우 밀착에 큰 영향은 없는 것으로 나타났으나 FF만 가지고 실험했기 때문에 제한적이며 실제 작업현장에서 밀착도에 영향을 주지 않는지를 결정하기 위해서는 작업장보호계수 (WPF)를 이용한 보다 많은 연구가 필요하다.

• Journal of the Korea Safety Management & Science
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• v.15 no.4
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• pp.97-103
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• 2013

The purpose of this study was to verify the change in temperature humidity perspiration of fire suit when applying phased intensive exercises to fire fighter wearing fire suit. For this study, three male fire fighters took basic physical test and performed 10 minute phased intensive exercises -exercise intensity I (30%VO2max), exercise intensity II (45%VO2max), exercise intensity III (60%VO2max) based on maximum oxygen consumption (VO2max)- wearing fire suit (helmet, boots, air respirator) in treadmill and took a rest. The result of study shows that the temperature in the suit elevated during stabilization period after each exercise intensity, humidity elevated as exercise intensity increased, perspiration elevated as exercise intensity increased. This study indirectly ascertained the fire suit's physiological change in fire fighters during field activities.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.23 no.4
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• pp.402-410
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• 2016

Purpose: Personal protective equipment (PPE) is critical to protect healthcare workers from pandemic outbreaks. This study was designed to identify nurses' knowledge, attitude and perceptions on PPE. Methods: Data were collected from 154 nurses working at a tertiary general hospital, where positively diagnosed and suspected patients were accepted and admitted during the Middle East Respiratory Syndrome Coronavirus outbreak in 2015. The PPE tool consists of 20 items for knowledge, and 5 each for attitudes and perceptions. Results: Overall, knowledge for PPE was higher than moderate (76.95/100), but there was a lack for items related to powered air purifying respirator (PAPR). For attitudes, willingness to work in pandemic outbreaks was the most positive (4.04/5.00). Goggles and PAPR were perceived as the most uncomfortable barriers to work. There was no correlation between knowledge, attitude and perceptions, despite a strong positive correlation between attitude and perceptions. PPE training was identified as a factor to improve knowledge and attitudes on PPE. Conclusion: To respond to pandemic influenza, nurses need to expand their knowledge on PPE up to Level C, and be updated through regular training. Study findings suggest that repetitive studies targeting nurses and other healthcare workers at various hospital settings are necessary.

• Fire Science and Engineering
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• v.30 no.2
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• pp.87-91
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• 2016

Recently, it has been increasing an incidence of heart diseases which is a causative factor in sudden death as Korean population structure has been changing to an aging society. There is growing needs for A portable ventilator which automatically be operated by the pressure of the supplied oxygen and has been spread worldwide. So, we would like to present test methods in accordance with the performance requirements which are important for components of a respirator and a portable ventilator itself. And also would like to find the most suitable condition of internal pressure reduction for the performance requirements according to the changing conditions of internal pressure reduction setting of a portable ventilator.

• Archives of Plastic Surgery
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• v.45 no.4
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• pp.375-378
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• 2018

In this report, we present a case of successful treatment of a bowel fistula in the open abdomen by perforator flaps and an aponeurosis plug. A 70-year-old man underwent total gastrectomy and developed anastomotic leakage and dehiscence of the abdominal wound a week later. He was dependent upon extracorporeal membrane oxygenation, continuous hemodiafiltration, and a respirator. Bowel fluids contaminated the open abdomen. Two months after the gastric operation, a plastic surgery team, in consultation with general surgeons, performed perforator flaps on both sides and constructed, as it were, a bridge of skin sealing the orifice of the fistula. The aponeurosis of the external oblique muscle was elevated with the flap to be used as a plug. The perforators of the flaps were identified on preoperative and intraoperative ultrasonography. This modality allowed us to locate the perforators precisely and to evaluate the perforators by assessing their diameters and performing a waveform analysis. The contamination decreased dramatically afterwards. The bare areas were gradually covered by skin grafts. The fistula was closed completely 18 days after the perforator flap. An ultrasound-guided perforator flap with an aponeurosis plug can be an option for patients suffering from an open abdomen with a bowel fistula.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.9 no.2
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• pp.79-89
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• 1999

A quantitative fit test, condensation nuclei counting (Portacount 8025, TSI), was performed concurrently with a banana oil (isoamyl acetate: IAA) qualitative fit test (MSA) to evaluate reliability on IAA QLFT and correlation between two methods. One brands of quarter mask (3M model 7500 medium) was prepared for QLFT with HEPA filter and gas & vapor removing media, i.e., combination cartridge. 110 subjects (65 male, 45 female) were fit tested QNFT and QLFT each three times. For a wearer combination having a FF<10, as determined by CNC QNFT, the point es timate (${\beta}$-error) of the probability of that combination not being rejected by the banana oil QLFT was found to be 0.0 with 95% confidence that this statistic is not expected to exceed 0.15. For a wearer combination having a FF<100, as determined by CNC QNFT, the point estimate of the probability of that combination not being rejected by the banana oil QLFT was found to be 0.07 with 95% confidence that this statistic is not expected to exceed 0.13. The uncertainty associated with each estimate, however, is large due to the small number of study subjects with inadequately fitting respirators.

• Journal of Chest Surgery
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• v.24 no.7
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• pp.693-700
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• 1991

A rare case of the association of distal aortopulmonary septal defect, aortic origin of the right pulmonary artery, intact ventricular septum, patent ductus arteriosus and interrupted aortic isthmus in a 40-day-old infant is reported. The infant was suffered from two operations with an interval of nine days. At the first operation a 10mm polytetrafluoroethylene prosthesis was inserted instead of the interrupted aortic isthmus and ductus was ligated via the left posterolateral thoracotomy. But the patient could not be weaned from the respirator because of large amount of left-to-right shunt. So the total correction was subsequently performed after an interval of nine days. At the second operation, tunneling of the right pulmonary artery to the main pulmonary artery through the aortopulmonary septal defect was performed using the Dacron patch via a longitudinal transaortic approach and a separate autologous pericardial patch was applied to the longitudinally incised margins of the anterior wall of the ascending aorta. The second postoperative course was relatively uneventful except some respiratory distress and nutritional problems. Now he is at 6 months of age and thrives well without any symptom. Because the success of the surgical repair of this complex anomalies depends upon the accurate diagnosis and meticulous design of each step of procedure prior to operation these problems are also discussed.