호흡기보호구의 밀착계수와 안면구조의 관계

한돈희,Han, Don-Hee 대한예방의학회 1998 Journal of Preventive Medicine and Public Health Vol.31 No.3

In many developed countries, for example, USA, respirator fit testing is required before entering specific work environment to ensure that the respirator worn satisfies a minimum of fit and that the user knows when the respirator fits properly. Unfortunately because we have not fit test regulation in Korea, a lot of workers wearing respirators may be potentially exposed to hazards. This study was conducted to evaluate the fitting performance for respirators and correlation fit factors with facial dimensions of wearers. 110 subjects (70 males, 40 females) were fit tested for three quarter masks, i.e., two domestic-made Mask 2, and Y and one foreign-made Mask T using PortaCount 8020. A facial dimension survey of the same subjects was conducted to develop a facial dimension grids fer correlation fit factors with facial dimension parameters. A facial dimension grid was developed on the basis of face length and lip length for quarter masks. The results obtained were as follows : 1 Fit factors of Mask T were much higher than those of Masks Z, and Y. 2. Males were fitted more properly than females. 3. Male in box 'f' of grid would be adequately fitted Mask Y and male in box 'b', 'e', 'f', 'h' of grid would be sufficiently fitted Mask T. Female in box 'h' of grid may have a good fitting performance for both Mask Y, and T. But subjects in all boxes of grid would be inadequately fitted Mask Z.

환기가 불량한 실내공간에서, 담배연기에 의한 CO, $CO_2$, TVOC 및 에어로졸의 변화

한돈희,박수진,류지혜,Han Don-Hee,Park Soo-Jin,Ryu Ji-Hye 한국환경보건학회 2006 한국환경보건학회지 Vol.32 No.2

Number of aerosol, CO, $CO_2$ and TVOC after one-, two-, three-cigarettes smoking were monitored with time every 10 minute for 180 minutes in the seminar room (volume $51.1m^3$) when poorly-ventilated. IAQ monitor (IAQRAE, model PGM-5210) and PortCount (TSI, model 8020) were used for monitoring. Aerosol was decreased with exponential decay equation and it was estimated that number of aerosol would be long suspended (one cigarette 75/cc. two cigarettes 66/cc, three cigarettes 141/cc by 8hrs after smoking). While CO was also decreased with exponential or linear decay equation and correlated with number of aerosol strongly, TVOC and $CO_2$ were increased with linear equation in accordance with time lag. Most of TVOC and $CO_2$ were above standard levels of Korean Indoor Air Quality (Ministry of Environment) without regarding number of cigarettes. When naturally ventilated, all of CO, $CO_2$ and TVOC concentrations were dramatically decreased below standard levels of Korean Indoor Air Quality.

실험실습용 국소배기 기초실험장치의 개발

한돈희,박민규,Han, Don-Hee,Park, Min-Kyu 한국환경보건학회 2005 한국환경보건학회지 Vol.31 No.5

To enhance educational effect for exhaust ventilation system, more instructive educational engineering such as experimental system should be needed. This study was performed to 1) manufacture the basic experimental system for local exhaust ventilation, 2) experiment with this system and 3) develop methodology of exhaust ventilation education. With this system, three pressures (static pressure(SP), velocity pressure(VP) and total pressure(TP)) were measured and illustrated and the graphic shapes agreed to theoretical ones relatively. Entry loss factor ($F_h$) of each hood was found to be different with hood shape, duct velocity and flow rate. This result implies that precise $F_h$ should be determined case by case and a industrial hygienist should not be dependent on the existing values. Pressure loss using velocity pressure method and characteristics of air movement near hoods using fume were grasped with this system. But larger system should be recommended to produce more precise experimental results.

방진마스크의 안면부 누설률에 관한 연구

한돈희,Han Don-Hee 한국환경보건학회 2004 한국환경보건학회지 Vol.30 No.5

Korean certification regulation for particulate filtering respirators requires inward leakage (IL) test as European Standards (EN) and the standard levels of regulation are the same as those of EN. This study was conducted to evaluate particulate filtering respirators being commercially used in the market by using IL and assess the characteristics of IL. The study began with discussing the concept of IL, comparison of IL with fit test, and IL measurement method. Three brands of half masks and 10 brands of filtering facepieces (two top class, four 1st class and four 2nd class), total 13 brands respirators, and 10 test panels (subjects) who were classified in 9 facial grids in accordance with face length and lip length, were selected for IL test. IL tests were conducted in the laboratory of 3M Innovation Center which was established by EN standard. As expected ILs of half masks were lower than those of filtering facepiece mask. ILs of half masks and some filtering facepieces were significantly different in manufacturers. ILs of 1st class filtering facepieces were found to be much more than those of 2nd class and thus the result would cause wearers to get confused to select a mask. Four of six brands being no compliance with standards were thought that they should be tested again for certification because of a lot of differences from standards. There were no significant differences among ILs of five exercises. In 6 out of 13 brands lognormal distribution of ILs may be a better fit distribution and in 7 brands both lognormal and normal distributions were rejected. The result indicates that geometric mean may be better than arithmetic mean to establish standard.

사고대비물질 개인보호구 선정에 관한 연구(1):: 물질유해성 및 작업위해성 분석

한돈희(Don-Hee Han),정상태(Sang-Tae Chung),김종일(Jong-Il Kim),조용성(Yong-Sung Cho),이청수(Chung-Soo Lee) 한국환경보건학회 2016 한국환경보건학회지 Vol.42 No.6

Objectives: According to the new Chemical Control Act from the Korean Ministry of Environment (2014- 259), workers handling hazardous chemicals should wear personal protective equipment (PPE). However the act simply states in basic phrases that every worker handling one or more of the 69 listed chemicals should wear PPE and does not consider the unique hazard characteristics of chemicals and work types. The main purpose of this study is to provide basic data to revise the act to suit particular work processes and situations. Methods: The hazard rank of the substances was classified based on hazardous characteristics such as LC50 and vapor pressure using matrix analysis. The workplace exposure risk of the substances was also determined through a matrix analysis based on the previously determined hazard ranks and the demands of manual handling together with the likelihood of accident frequency of the operation combined with the exposure of workers during spill accidents. Results: To meet the demands for developing subsequent guidelines for the risk-based application of PPE in hazardous workplaces, this study sorted the 69 listed chemicals into five hazardous categories based on their LC50 and vapor pressures, and also assigned exposure categories according to exposure vulnerability for various types of work which are frequently performed throughout the life cycle of the chemicals. Conclusion: In the next study, an exposure risk matrix will be produced using the hazard rank of chemicals and workplace exposure risk, and then PPE will be selected to suit the categories of the exposure risk matrix.

물의 경도가 흰쥐의 신장, 간에서 중금속 축적에 미치는 영향

한돈희(Don Hee Han) 한국환경보건학회 1988 한국환경보건학회지 Vol.14 No.2

It has been suggested that calcium is on1y one of many metals that compete with toxic metals in the body. Therefore, this study was carried out to determine the influence of water hardness on accumulation of heavy metals in rats. The seventy-five rats were divided into control and case groups. Case group was subdivided into four subgroups in proportiOll to the concentration of water hardness respectively, such as, 0, 250, 500, 1000ppm. Control group was fed on only deionized water, but case groups were fed on hard water with ionized heavy metals (Cd 150mg + Pb 300mg + Cu 300mg/l) for 20, 40, 60 days. The concentrations of cadmium, lead and copper were measured by atomic absorption spectrophotometry (perkin Elmer 2380) in livers and kidneys. πle results of the study are summarized as followíng; 1. The concentration of cadmium accumu1ation showed the tendency of decrease in proportion to water hardness in both livers and kidneys of rats having been fed for only 60 days, respectívely. 2. In only livers of rats having been fed for 60 days, essentíal metal, copper had the tendency of decrease according as hardness ín water. 3. 1t was impossible to compare case wíth control about the tendency of lead accumulatíon because there was no difference between the two in livers and kidneys respectively.

보건용 마스크의 분진포집효율, 흡기저항 및 CO₂ 농도

한돈희(Don-Hee Han),김일순(Il Soon Kim) 한국환경보건학회 2020 한국환경보건학회지 Vol.46 No.1

Objectives: To identify the degree of physical burden, a determination was undertaken of dust collection efficiency, inhalation pressure, and CO2 concentration related to health masks certified by the Ministry of Food and Drug Safety (MFDS). Methods: Twenty health masks were purchased on the market. Dust collection efficiency and inhalation pressure were determined in the same manner as in MFDS certification testing, respectively using TSI Model 8130 (TSI, U.S.) and ART Plus (Korea). CO2 concentrations for 20 subjects using a CO2 analyzer (G100, G150, Geotechnical Instrument Ltd., UK) were measured with a similar method as a total inward leakage test. In addition to CO2 levels, dead space volumes in the masks was determined for predicting concentrations of CO2 in inhalation air. Results: Most of the dust collection efficiencies found for the 20 masks were far higher than the standard. Four KF94s met KF99 and four KF80s even met KF94. Most inhalation pressures were also much lower than the standard, with many almost one-half of the standard. The mean and standard deviation of CO2 concentration in the mask were 2.9±0.44%. Considering dead volume, the prediction for CO2 concentration in the inhalation air was 4,395±1,266 ppm. Conclusions: For healthy men and women, the dust collection efficiency and inhalation pressure of health masks were not at a level that would affect their health. Although CO2 levels in the inhalation air were predicted not to affect health, research on the physiological effects of health masks on Koreans is needed for more precise research.

모발중 Pb,Cu 함량에 관한 폭로군 및 비 폭로군 연구

한돈희(Don Hee Han) 한국환경보건학회 1987 한국환경보건학회지 Vol.13 No.2

For the purpose of evaluating metal content in human hair, the auther carried out the comparat:lve study of 55 samples of exposed residents surrounding lead & copper smelter and 55 samp1f:s of non.exposed. Hair samples were stingent1y washed before analysis for lead and copper by atomi<: absorption spectroscopy. The resu1ts obtained were as follows; 1. Hair s없nples of exposed residents contained more lead than non-exposed but showed no signiflcance statistically (P>O.05). 2. Also copper in the hair of exposed residents showed more content than non-exposed but no significance statistic외ly (p>O.05). 3. Lead and copper in the hair of exposed residents revealed a high degrçe of correlation (r= 0.8442, p<O.005). 4. Lead did not accumulate in hair with age in two group residents and copper in the hair of non-exposed residents maintained in al1 age. 5. The content of lead and copper in the hair of two group residents showed very considerable variation from individual to individua1.

Leq, Lr, TNI 평가법에 의한 부산시 주요 상가변의 소음도 분석

한돈희(Don Hee Han) 한국환경보건학회 1990 한국환경보건학회지 Vol.16 No.1

To evaluate the degree of traffic noise at the main shopping districts, 30 sites, in Pusan and produce the basic data of traffic noise counterplan, this research was conducted. Noise rating methods utilized were Leq( equivalent continuous sound level), Lr (rating sound level) and TNI(traffic noise index). As the results, all sites passed beyond Korean Environmental Noise Standard 70 dB(A) in Leq and 46.7% sites fell under ‘widespread complaints’step, 40.0% ‘threat of com. munity action’step, 13.3% ‘vigorous community action’step by Lr ratings, and 30.0% sites were over acceptable TNI criteria of 74. Therefore, traffic noise at Pusan shopping districts was very severe.

작업장에서 사용 가능한 방독마스크 정화통 교체주기 프로그램의 개발(1) -폐정화통을 이용한 파과시간 예측 실험

한돈희 ( Don Hee Han ),이상영 ( Sang Young Lee ) 한국산업위생학회 2008 한국산업보건학회지 Vol.18 No.3

Many researches for service-life of chemical cartridges of respirators have been performed in many countries. On the result of these researches a few softwares programs were eventually developed to be used. In spite of that, it is difficult to apply these researches and softwares practically in the work spot because of too many factors that influence on service-life of chemical cartridges. This study was the first of two conducted for the purpose of developing program for estimating exchange period or service-life of chemical cartridges available feasibly in the workplaces. Collecting plan of cartridges discarded after use is in principle that three cartridges from three workers at a time, three steps of 1/2 exchange time due to smelling, just routine exchange time and 1.2 to 1.3 expanded time of routine exchange, total nine cartridges are collected in the same job site. 33 cartridges for organic vapor were collected in paint spray process of ship yard and paint factory, and 6 cartridges for acid were collected in plating process. These cartridges were analysed the remaining breakthrough time in 3M Innovation Center. Challenge vapor and breakthrough concentration were complied with Korean regulation for chemical cartridge respirators. Estimated breakthrough time was determined from previously used time plus breakthrough time for the remaining. Exchange period of cartridge would be the shortest time among three estimated breakthrough times. On the result breakthrough time for organic vapor was found to be relatively easily estimated, but that for acid aerosol or vapor was difficult to be confident. Even though this method was difficult to be precisely predicted exchange period of cartridge, it could be an alternative program practically available in the job site.