B형 간염 전파관련요인에 관한 역학적 연구

오민화,Oh, Min-Hwa 대한예방의학회 1984 Journal of Preventive Medicine and Public Health Vol.17 No.1

An attempt to confirm the associations of some selected risk factors of HBV infection and measure their risks, a cross-sectional study with 1,209 urban office workers was carried out. For the study, a simple questionnaire which contained several questions on personal experience and behaviors on several known selected risk factors of HBV infection was applied to each subject, and the Hepatitis B virus surface antigen and its antibody were checked by RPHA and PHA method, respectively. Risk factors chosen for this study were experience of blood transfusion and personal contact variables, such as frequencies of eating-out, drinking after office hours, going to tea room, sharing cigarettes, etc. The results obtained were as follows: 1. The proportion of HBsAg positive was 10.6%, and total HVB infected including the Anti-HBs positive cases without vaccination was 44.2%. Both were higher in male than in female. 2. Frequent personal contact through glasses and dishes in eating-outs and drinkings turned out not to be a significant risk factor of Hepatitis B surface antigenecity. 3. Frequent visits to tea room was a significant risk factor of HBV infection which combined HBsAg positive cases and Anti-HBs cases who had not received HBV vaccination. The odds ratio was 1.56 4. Blood transfusion was not a significant risk factor of both HBsAg positive and total HBV infection. In summary, indirect oral contacts through eating-outs and drinkings was not significant risk factor in Korea at least between adults. Blood transfusion is no more major source of HBV infection in Korea probably because the adquate screening test of HBsAg for the blood donors is being made.

흰쥐규폐증에서 기관지 폐포 세척액내 세포변화

임영 ( Young Lim ),윤임중 ( Im Goung Yun ),오민화 ( Min Hwa Oh ) 대한결핵 및 호흡기학회 1991 Tuberculosis and Respiratory Diseases Vol.38 No.2

암모니아 가스 폭로후에 발생한 폐 섬유화증 1예

임현우,임영,윤임중,오민화 大韓産業醫學會 1991 대한직업환경의학회지 Vol.3 No.2

Ammonia is highly water soluble and causes injury primarily to the mucous membranes and the upper respiratory tract. Patients who survive the initial exposure to ammonia can develop tracheobronchitis, bronchoconstriction, and mucous hypersecretion. Most of the affected persons well recover, but some of them may suffer from the progressive findings such as bronchiectasis, bronchiolitis obliterans and rarely pulmonary fibrosis. We experienced bronchiectasis and bronchiolitis obliterans in a worker (34 yr, male) following ammonia burns on the respiratory tract. This case was exposed to anhydrous ammonia fumes for several minutes by bursting of ammonia pipe-line in the cold storage room of a refrigerator boat. Thereafter, he was admitted by severe dyspnea and ocular damage at a hospital in the vicinity. Intubation and mechanical ventilation were applied to him under the impression of adult respiratory distress syndrome. After 193 days of accident, he was transfered from the hospital to us, and complained of intermittent hemoptysis, recurrent bronchial infectious symptoms, massive pyogenic sputum, hoarseness, and dyspnea. The severe bronchiectatic change was confirmed in both lung field by bronchogram, however, bronchiolitis obliterans was also suspected by bronchoscopy with transbronchial lung biopsy and lung perfusion scan. So we report a case of severe bronchiectatic change and bronchiolitis obliterans after exposure to ammonia gas.

양안 근점거리의 분포형

구정완,오민화,이승한 가톨릭대학산업의학센타 산업의학연구소 1991 韓國의 産業醫學 Vol.30 No.2

Near point distance for both eyes of 71 healthy subjects. who no special eye conditions, were measured in order to clarify their distribution form and to select a measure that is suited to continuous observation of visual fatigue of VDT workers. The results were as follows: 1. Near point distance for both eyes(appear. disappear) followed normal distribution only after natural log-transformation(Shapiro-Wilk test). 2. The variance and the coefficient of variation of near point distance(appear) were 0.04 and 4.13, respectively, while they were 0.08 and 6.30 in near point distance(disappear). The findings suggested that near point distance(appear) could be a preferable measure to near point distance(disappear)in the sequential monitoring of visual fatigue. 3. The mean near point distance(appear, disappear)for both eyes of study subjects were 138,82 mm in the age4 group of 20-29 years and were 156,97 mm in the age group of 30-39 years. respectively.

광물성 섬유의 수산이온기 생성이 흰쥐 폐포대식세포의 세포독성과 적혈구 세포막의 지질과산화에 미치는 영향

김경아,윤임중,김지홍,장황신,오민화,임영,박정일 大韓産業醫學會 1997 대한직업환경의학회지 Vol.9 No.3

There is some evidence suggesting that the mechanism of pulmonary toxicity of natural fibrous silicate, asbestos, is related to the generation of oxygen-based free radical. Especially the hydroxyl radical(·OH) is believed to be the most reactive one. ·OH is a potent toxic oxidant, ·OH is which means highly cytotoxic, genotoxic and carcinogenic. Nevertheless there has been no previous report about ·OH generation from man-made mineral fibers except asbestos. In this paper we tested the hypothesis that both cytotoxicity of alveolar macrophage and lipid peroxidation of erythrocytes are associated with ·OH production by mineral fibers in vitro. The results were as follows: 1. ·OH production in vitro was progressively increased by the concentration dependent pattern with the same mineral fiber. The production of ·OH in vitro by man-made mineral fiber was markedly decreased compared with that of natural mineral fiber except rock wool. 2. Lipid peroxidation of mineral fiber-exposed erythrocyte suspension was significantly increased compared with that of phosphate-buffered saline(PBS) control group. Lipid peroxidation in amosite and chrysotile group was larger than that of other mineral fibers. 3. There was a significantly positive correlation between ·OH production in vitro and lipid peroxidation of mineral fiber-exposed erythrocyte. 4. All of mineral fibers were related to the cytotoxicity of alveolar macrophage in concentration-dependent fashion. Chrysotile and amosite were more cytotoxic than crocidolite. Among man-made mineral fibers, ceramic fiber was the most cytotoxic to alveolar macrophage. The viability of alveolar macrophage exposed to asbestos was markedly decreased compared with that of man-made mineral fiver at the same concentration. 5. There was the significant negative correlation between the production of .OH and the viability of alveolar macrophages. From these results, we can conclude that the production of ·OH in vitro was strongly correlated with the cytotoxicity of alveolar macrophage and the lipid peroxidation in mineral fiber-exposed erythrocyte. And we documented that man-made mineral fiber could generate .OH in vitro less than asbestos.

청력측정시 헤드폰 Audiocup부착 여부에 따른 청력수준의 차이

오민화,피영규,이원철,박정일,구정완 카톨릭대학 산업의학 센타 산업의학연구소 1997 韓國의 産業醫學 Vol.36 No.2

This study was conducted to evaluate hearing thresholds according to wearing audiocups. The subjects were composed of white-collar workers of a non-noise- exposed population for general health examination and healthy person for multiphasic health examination in hospital of university. Using self-recording questionnaire method, general characteristics, past or present noisy job, past illness history, past military service, present upper respiratory tract infection and taking ototoxic drug use were obtained. Then they were examined otoscopic test and audiometry of 1,000㎐ and 4,000㎐ in the soundproof booth The collected data excluded factors influencing hearing were analysed to wearing audiocups for 186 subjects on 20-59 years of age and some major results are as follow: 1. Hearing thresholds of group with audiocups were slightly decreased than that of group without audiocups in all years of age for 1000㎐. 2. Hearing thresholds of group with audiocups were significantly decreased than that of group without audiocuos in 20-29, 40-49 years of age for 4000㎐. In 30-39, 50-59years of age, it was not signigicant differences between two groups due to small number of subjects. In conclusion, it suggests that the audiometry wearing audiocups are more accurate because these are the most applicable to excess noise problem in testing areas. There-fore, that will reduce numbers of persons who should take the close examination and prevent the worker from wasting work times and also reduce costs of examination.

이명의 유병률 및 이명유무에 따른 청력역치수준

이원철,최병철,오민화,박정일,김현욱,구정완 大韓産業醫學會 1999 대한직업환경의학회지 Vol.11 No.3

Objectives: In order to establish prevalence and characteristics of tinnitus and hearing thresholes according to tinnitus, this study was carried out. Methods: Nine hundred and thirty two subjects, undergone human dock or general health check-up and been in college, were surveyed to the questionnaire on the general characteristics, past medical histories, life styles, subjective symptoms about hearing, taking ototoxic drugs and were conducted on the hearing thresholds by pure tone audiometry. Results: Of the total population, 98 reported tinnitus, giving an overall prevalence of 10.5%, prevalence of tinnitus in the subjects with the factors influencing hearing thresholds were 17.4%, prevalence without the factors influencing hearing thresholds were 7.5%. Frequency of tinnitus of the total population was the highest in 'once per several months' (39.6%) and followed by 'once per several days'(29.7%), 'all day long' (16.5%) and 'several times per day' (14.3%). Complaint site of tinnitus was 41.8% in left ear or right ear, 39.6% in both ear and 18.7% in head. The 13.6% of the total subjects complained sleep disturbance. Hearing thresholds in the subjects without the factors influencing hearing thresholds tended to increase or decrease in 20 and 30 years old according to tinnitus, but those with tinnitus tended to increase more than those without tinnitus in 40 and 50 years old. Conclusions: Results also provide evidence that reports of tinnitus at the time of annual audiometric testing may be useful in identifying workers at greater risk for developing significant shifts in hearing thresholds. Awareness of the possible occurrence of tinnitus may encourage workers to cooperate more actively in a company hearing conservation programme.