병원내 공기 중 바이오에어로졸의 분포와 동정에 관한 연구

Abstract

[한글]

병원내 공기 중에 부유하는 바이오에어로졸의 분포와 동정을 하고자 450병상 규모의 종합병원을 선정하고 중앙로비, 중환자실, 일반외과병실, 병리검사실과 비교지점인 측정병원의 실외를 대상으로 미생물학적 요인과 물리적 환경요인을 조사하여 다음의 결과를 얻었다.

온도와 상대습도는 실외를 제외하고 오전, 오후 비슷하였으며 이산화탄소는 중앙로비에서 오전에 830ppm, 오후에 1,200ppm이었다. 악취지수는 중환자실에서 1,340ppm으로 가장 높았으며 세균의 형태를 조사한 결과 그람양성구균이 68.6%, 그람양성간균이 25.6%, 그람음성간균이 1.2%이었다. 세균을 동정 한 결과 catalase 양성이 78%, CNS(Coagulase negative staphylococcus)균이 75%를 차지하였다. 병원내 공기 중에 부유하는 미생물은 비병원성 포도상구균이 주로 발견되었으나 건강에 영향을 미치는 측정 장소별 병원성 균의 농도와 비율은 중앙로비 8.5 Colonies Forming Unit(CFU)/㎥(1.7%), 중환자실 9.0 CFU/㎥(2.9%), 일반외과병실 11.5 CFU/㎥(2.7%), 병리검사실이 7.0 CFU/㎥(2.0%)로 일반외과병실에서 병원성균이 가장 많이 검출되었으며 비교지점인 실외에서는 병원성균이 검출되지 않았다. 배양된 세균은 12속의 균이 분리되었고, 포도상구균속 626균주(50.4%), Micrococcus속 182균주(14.7%), Corynebacterium속이 164균주(13.2%)이었다. 장소별 세균의 농도는 중앙로비 515 CFU/㎥, 중환자실 353 CFU/㎥, 일반외과 병실 475 CFU/㎥, 병리검사실 362 CFU/㎥, 실외가 211 CFU/㎥로 중앙로비와 일반외과병실에서 세균의 농도가 가장 높았다. 배양된 진균을 관찰 한 결과 Cladosporium 31%, Penicillium 25%, Aspergillus가 17%이었다. 진균의 장소별 농도는 중앙로비 280 CFU/㎥, 일반외과병실 219 CFU/㎥, 병리검사실 235 CFU/㎥, 중환자실 180 CFU/㎥, 실외가 157 CFU/㎥으로 중앙로비의 경우 세균 농도와 진균농도가 동시에 높았다. 세균과 진균의 입자크기를 측정한 결과 세균은 1단계 (7㎛이상)와 5단계 (1.1-2.1㎛)에서 각각 23.3%와 24.5%로 비슷하게 높았고, 진균은 1단계에서 38.3%로 가장 높았다. 사람의 폐를 통하여 호흡성질환을 일으킬 수 있는 4㎛ 미만의 입자 크기인 3단계 (3.3㎛-4.7㎛)이하에서 세균이 61.2%, 진균이 44.7%를 차지하였으며 세균과 진균의 시간별 농도는 전반적으로 오전 보다 오후시간대에 모든 장소에서 높았다.

연구 결과를 종합하면 중앙로비와 일반외과병실에서 바이오에어로졸의 농도가 높았으며 대부분의 세균과 진균은 비병원성균이었다. 병원내 바이오에어로졸로 인한 공기감염을 감소시키기 위해서는 적절한 환기와 주기적으로 오염도를 조사하여 예방하는 적극적인 대책이 필요하다.

[영문]This study purposed to examine the distribution and identification of bio-aerosols floating in the air inside a general hospital with around 450 beds and investigated the biological and physical environmental indicator of the main lobby, the intensive care unit, general surgical rooms and the pathologic laboratory as well as of an outdoor of the hospital as a spot for comparison. The results of this study are as follows.

Temperature and relative humidity in the morning and in the afternoon were similar among the places except the outdoor. Carbon dioxide in the main lobby was 830ppm in the morning and 1,200ppm in the afternoon. Odor index was highest as 1,340ppm at the intensive care unit and, according to the morphological investigation of microbes, 68.6% were Gram-positive micrococci, 25.6% were Gram-positive bacilli and 1.2% were Gram-negative bacilli. According to identification microbes, 78%were Catalase-positive and 75% were Coagulase-negative staphylococci (CNS). Most microbes floating in the air inside the hospital were non-pathogenic staphylococci but the concentration (percentage)of pathogenic microbes that affect health was 8.5Colonies Forming Unit(CFU)/㎥(1.7%) at the main lobby, 9.0CFU/㎥(2.9%) at the intensive care unit, 11.5CFU/㎥(2.7%) at general surgical rooms and 7.0CFU/㎥(2.0%) at the pathologic laboratory. Thus pathogenic microbes were detected at the highest level at general surgical rooms and none at the outdoor. From cultivated microbes were of which626 strains (50.4%) were Staphylococcus, 182 (14.7%) were Micrococcus, and 164 (13.2%) were Corynebacterium. The concentration of bacteria by place was 515CFU/㎥ at the main lobby, 353CFU/㎥ at the intensive care unit, 475CFU/㎥ at general surgical rooms, 362CFU/㎥ at the pathologic laboratory, and 211CFU/㎥at the outdoor. Thus it was highest at the main lobby and general surgical rooms. According to observing cultivated fungi, 31% were Cladosporium, 25% were Penicillium and 17% were Aspergillus. The concentration of fungi by place was 280CFU/㎥ at the main lobby, 219CFU/㎥ at general surgical rooms, 235CFU/㎥ at the pathologic laboratory, 180CFU/㎥ at the intensive care unit and 157CFU/㎥ at the outdoor. Thus both the concentration of bacteria and that of fungi were high at the main lobby. According to measuring the particle size of bacteria and fungi, the distribution of bacteria by size was concentrated on Stage 1 (over 7㎛) and Stage 5 (1.1-2.1㎛) at similar levels as 23.3% and 24.5% respectively, and that of fungi was concentrated on Stage 1 (over 7㎛) at 38.3%. In addition, 61.2% of bacteria and 44.7% of fungi were Stage 3 (3.3㎛-4.7㎛) or smaller, and those below 4㎛ can cause respiratory diseases. The concentration of bacteria and fungi over time was generally high in the afternoon than in the morning at all places.

The concentration of bio-aerosols was high at the main lobby and general surgical rooms where environmental indicator were poor, and most bacteria and fungi was non-pathogenic microbes. In order to reduce airborne infections caused by bio-aerosols at hospitals, it is necessary to take active measures including appropriate ventilation, regular survey of pollution level and preventive actions.