• Journal of Korean Neurosurgical Society
• /
• 제60권4호
• /
• pp.481-483
• /
• 2017

Sphingomonas paucimobilis (S. paucimobilis) is a gram negative bacillus. It has existed in soil, drinking water and plants. It has been isolated from distilled water tanks, respirators, and hemodialysis devices at the hospital setting. Patients with chronic disorders or immune suppression may be susceptible to infections with it. This microorganism has also been reported to infect healthy persons. Both nosocomial and community-acquired infections have been reported. So far, a variety of infections have been reported, including sepsis, septic pulmonary embolism, septic arthritis, peritonitis, and endophthalmitis. Only 2 cases of meningitis have been reported so far in the literature. So far, no previous reports of culture proliferation have been reported in patients with external ventricular drains, as was the case in our patient. Therefore, our case is the first to have S. paucimobilis proliferation in cerebrospinal fluid culture during intensive care unit stay for an external ventricular drain.

• International journal of advanced smart convergence
• /
• 제11권4호
• /
• pp.240-246
• /
• 2022

In order to measure the respiratory rate, one of the major vital signs, many devices have been developed and related studies have been conducted. In particular, as the number of wearers of respirators increases in the COVID-19 pandemic situation, studies have been conducted to measure the respiratory rate of the wearer by attaching an electronic sensor to the respirator, but most of them are cases in which an air flow sensor or a microphone sensor is used. In this study, we design and develop a system that measures the respiratory rate of the wearer using an air pressure sensor in a respirator. Air pressure sensors are inexpensive and consume less power than the other sensors. In addition, since the amount of data required for calculation is small and the algorithm is simple, it is suitable for small-scale and low-power processing devices such as Arduino. We developed an algorithm to measure the respiratory rate of a respirator wearer by analysing air pressure change patterns. In addition, variables that can affect air pressure changes were selected, and experimental scenarios were designed according to the variables. According to the designed scenario, we collected air pressure data while the respirator wearer was breathing. The performance of the developed system was evaluated using the collected data.

• 한국산업보건학회지
• /
• 제34권1호
• /
• pp.1-7
• /
• 2024

Objectives: The study was performed to investigate characteristics of hazardous factors regarding chemical(liquid lime) tank dredging workers by case survey. Methods: Field data such as working condition, MSDS and respirators applied to chemical tank dredging work were analyzed and the work environmental factors of noise and indoor air quality were measured to compare existing data with actual work situations. Results: No health hazards to workers due to working conditions were confirmed during dredging work inside the chemical storage tank. All air quality measurement data during dredging work satisfied the management standards, and there were no by-products. During dredging work, there was a significant change in noise depending on the type of work, but considering the noise reduction rate(NRR) of the earplugs worn by workers, there was no actual health hazard due to noise exposure. Conclusions: A fit test for respirator and the expiration date of the safety helmet should be observed to ensure an appropriate level of safety and health for dredging workers in the chemical storage tank.

• International Journal of Internet, Broadcasting and Communication
• /
• 제16권2호
• /
• pp.255-266
• /
• 2024

The purpose is to evaluate evacuation safety by simulating the toxic effects of hydrogen fluoride leaks in areas surrounding national industrial complexes and to suggest alternatives for areas that do not satisfy evacuation safety. For human casualties caused by hydrogen fluoride leakage accidents, Available Safe Egress Time (ASET) is calculated by the toxic effects quantified with the Areal Locations of Hazardous Atmospheres (ALOHA), an off-site consequence assessment program. The Required Safe Egress Time (RSET) is calculated through Pathfinder, an evacuation simulation program. Evacuation safety is assessed by comparing ASET and RSET. The ALOHA program was used to evaluate the time to reach AEGL-2 concentration in 12 scenarios. The Pathfinder program was used to assess the total evacuation time of the high school among specific fire-fighting objects. Of the 12 accident scenarios, ASET was larger than RSET in the worst-case scenarios 1 and 9. For the remaining 10 accident scenarios, the ASET is smaller than the RSET, so we found that evacuation safety is not guaranteed, and countermeasures are required. Since evacuation safety is not satisfactory, we proposed to set up an evacuation area equipped with positive pressure equipment and air respirators inside specific fire-fighting objects such as the high school.

• 한국산업보건학회지
• /
• 제10권1호
• /
• pp.170-178
• /
• 2000

Most of manufacturers try to produce the most efficient filter for respirators with the lowest breathing resistance. Filter performance depends on low penetration, i.e., high efficiency (%), and low pressure drop ($mmH_2O$). This study was performed to evaluate performance of respirator filters by quality factor ($q_F$) and suggest the direction for improvement of respirator filters of good quality in Korea. Two mechanical filters, S and K made in Korea, three filtering facepieces, S made in China, C made in Korea and M made in USA, which were widely used in the workplace, were selected and tested efficiency and pressure drop in accordance with flow rate, using with Automated Filter Tester Model 8110 (TSI, USA). The best quality factor within the same respirator filter categories was $0.0672cm^{-1}\;H_2O$ for mechanical filter S, $0.0698cm^{-1}\;H_2O$ for filtering facepiece M at flow rate of 32Lpm. Mechanical filter S would be the best suitable during heavy work since qulity factors decrease less sharply than any others as increased flow rates. It was necessary for mechanical filter S to lower pressure drop without increasing efficiency, but mechanical filter K should be increased efficiency and decreased pressure drop. While filtering facepiece M had the best quality performance of three ones, Sand C should get much higher efficiency and lower pressure for better performance.

• 한국안전학회지
• /
• 제35권3호
• /
• pp.105-115
• /
• 2020

This study compares the difference of fit factors (FF) and visual acuity according to masks and eyeglasses preferences for 54 participants. We the precautions and behaviors of discomfort when wearing masks of eyewear wearers. Contact lens discomfort and priority action of complaints was investigated Glasses fitting factors is Optical Center Height(OH), Vertex Distance(VD) and Pantoscopic Angle(PA). We measured those factors and expressed by the ratio of standard point and change point. Quantitative fit factor was measured by Portacount Pro+ 8038. Also, we selected to 6 exercises among 8 exercises OSHA QNFT (Quantitative Fit testing) protocol to measure the fit factors. The pass/ fail criterion of FF was set at 100. Visual acuity(VA) test chart is developed by Chunsuk Han was used, Descriptive statistics was performed. Descriptive statistics(SAS ver 9.2), it is used geometric means, Wilcoxon analysis(P=0.05) When wearing the mask preferentially, fit factor(FF) was high according to the step of glasses fitting parameter. on the other hand, when the glasses first choice, the visual acuity(VA) was high. there was no significant difference. In the case of fit factor (FF), mask first choice/ glasses first choice is OH (p=0.671/ p=0.332), VD (p=0.602/ p=0.571) and PA (p=0.549/ p=0.607). Visual acuity (VA), mask first choice/ glasses first choice is OH (p=0.753/ p=0.386), VD (p=0.815/ p=0.557) and PA (p=0.856/ p=0.562). The workers of workplace and office chose glasses but occupational health workers and students chose mask. In case of discomforts, it was suggested to remove the mask and tolerate discomforts. The main discomforts and usual action of lens were dryness, hyperemia, foreign body sensation, ophthalmodynia, decreased vision and glasses wearing. Therefore, it is necessary to develop a mask wearing method education program considering glasses fitting and develop a hybrid model that minimizes inconvenience when wearing glasses and a mask at the same time.

• 한국산업보건학회지
• /
• 제11권1호
• /
• pp.70-77
• /
• 2001

This study was conducted to identify the current status of occupational safety and health by checklist and to evaluate the airborne exposure to chemicals and to provide the appropriate recommendation for safety and health of laundries. A total of 20 laundries located in tile Gyungi district area were surveyed from July 20 to September 15, 2000. The prevalence of laundries having a stove and gas range were found to be 25 % and 55 %, respectively. Smoking is not allowed in 60 % of the laundries. Only 10 % of dry-cleaners were isolated. Ventilation systems in laundries had not been annually inspected. Most of the workers didn't put on respirators, MSDS were not available, and storage bottles did not contain warning labels. The bulk samples of dry cleaning agent include many chemicals that are not controlled by the MOL in Korea. The detected airborne organic solvents in the laundries were benzene, toluene, p-xylene, m-xylene, o-xylene, perchloroethylene, and 2-butoxy ethanol. The airborne concentrations of organic solvents were much less than the occupational exposure limits proposed by the Ministry of Labor(MOL) in Korea. But the concentrations of benzene exceeded the TLV of ACGIH. This study showed that the current status of occupational safety and health was not appropriate for workers in laundries. It is recommended that laundry workers should be educated for the treatment and storage of hazardous organic solvents to improve the occupational safety and health of the working environment as well as MSDS usage. Also, extended research and survey for the organic solvents that are not controlled by the MOL has to be conducted.

• 한국산업보건학회지
• /
• 제11권1호
• /
• pp.42-47
• /
• 2001

The purpose of this study was to investigate for filtration efficiency of several dust masks, comparing with filtration efficiency certified by KOSHA(Korea Occupational Safety & Health Agency), and to require of the right use of protective respirators. Using a welding fume generator and chamber, several dust masks, which were widely used in the workplaces in korea, were tested for their filtering efficiency for stainless steel arc welding fume. The filtration efficiency testing system consisted of a welding fume generator, a chamber and a filtration unit. The filtration unit was made of a mask which was inserted into the sampling cassette and another sampling cassette, which contained mixed cellulose ester filter paper. These two cassettes were connected with tubing. Stainless steel arc welding fume generator was delivered into an chamber. The welding fume in the chamber was passed into the filtration unit with flow rate of 30 liter/min. The welding fume filtration efficiency was evaluated by gravimetric measurement. Metal concentrations in the welding fume before and after filtration were measured with inductive coupling plasma analyzer. Following results were obtained: Filtration efficiency of welding fume for common hygienic mask was 63.82% and the average efficiencies for A, B, C, D, E, F and G masks were 94.62%, 96.58%, 83.20%, 82.76%, 77.25%, 86.55% and 93.22%, respectively. Our results indicate that dust masks used widely in the welding workplaces in korea are not proper for protecting worker's health and then the use of fume mask should be required.

• Carbon letters
• /
• 제13권2호
• /
• pp.109-114
• /
• 2012

A nuclear, biological, chemical (NBC) canister was indigenously developed using active carbon impregnated with ammoniacal salts of copper (II), chromium (VI) and silver (I), and high efficiency particulate aerosol filter media. The NBC canister was evaluated against carbon tetra chloride ($CCl_4$) vapours, which were used as a simulant for persistent chemical warfare agents under dynamic conditions for testing breakthrough times of canisters of gas masks in the National Approval Test of Respirators. The effects of $CCl_4$ concentration, test flow rate, temperature, and relative humidity (RH) on the breakthrough time of the NBC canister against $CCl_4$ vapour were also studied. The impregnated carbon that filled the NBC canister was characterized for surface area and pore volume by $N_2$ adsorption-desorption isotherm at liquid nitrogen temperature. The study clearly indicated that the NBC canister provides adequate protection against $CCl_4$ vapours. The breakthrough time decreased with the increase of the $CCl_4$ concentration and flow rate. The variation in temperature and RH did not significantly affect the breakthrough behaviour of the NBC canister at high vapour concentration of $CCl_4$, whereas the breakthrough time of the NBC canister was reduced by an increase of RH at low $CCl_4$ vapour concentration.

• 한국화재소방학회논문지
• /
• 제18권3호
• /
• pp.95-102
• /
• 2004

본 논문은 국내에서 소방관이 사용하고 있는 공기호흡기용 압축공기를 분석하였으며, 공기호흡기를 착용하는 진압대원 및 구조대원을 대상으로 공기호흡기 사용실태에 대한 설문을 받아 분석함으로서 문제점을 파악하고, 국내 및 선진 외국의 압축공기에 기준을 비교ㆍ검토하였다. 설문조사 결과 전체 응답자의 약 75% 이상이 공기호흡기를 착용 후 간단한 이상증상이 있었으며, 이상증상을 호소한 사람들은 '페스꺼움' 과 '두통'을 가장 많이 호소하였다. 한편, 관리적인 측면에서는 콤프레서 필터의 유지ㆍ관리가 잘 안되고 있었다. 현재 국내에서 소방대원이 사용하고 있는 공기호흡기 호흡용 압축공기는 공업용 공기와 별다를 바없이 사용되고 있었으나, 유럽, 캐나다 및 미국과 같은 선진국의 경우 소방관이 착용하는 공기호흡기 호흡용 압축공기의 조성에 대한 별도의 규정이 있다. 국내에서 사용 중인 압축공기를 공기분석기를 이용하여 성분분석을 행한 결과 모든 시료에 있어서 수분의 함량은 국제적인 기준에 못미치는 것으로 나타났다.