This study examines the effects of surrounding outdoor environmental characteristics in multi-use public facilities that are used by the susceptible population, on the concentration and distribution of indoor airborne bacteria. For this study, areas were divided into ‘factory area,’ ‘city area,’ and ‘forest area.’ The research was conducted from October 2017 to April 2018, and the selected target facilities were daycare centers, hospitals, postpartum care centers, and nursing homes for the elderly. In order to measure airborne bacteria, indoor air samples were collected using a six-stage viable particulate cascade impactor, and airborne bacteria samples were collected using MCE (Mixed cellulose esters) filters. Moreover, the outdoor airborne bacteria concentration was also measured to determine the concentration ratio (I/O ratio) of the total indoor airborne bacteria and total outdoor airborne bacteria concentrations. The results showed that the total outdoor airborne bacteria concentration was highest in the city area, with 74.2 ± 60.0 CFU/m3, and the lowest in the factory area, with 45.9 ± 35.8 CFU/m3. Furthermore, the distribution of the total outdoor airborne bacteria concentrations significantly differed across each surrounding environment (p < 0.05). On the other hand, no statistically significant difference in total indoor airborne bacteria concentrations, according to surrounding environments, was observed (p > 0.05). These findings suggest that the concentration of outdoor airborne bacteria differs across surrounding environments, unlike that of the indoor airborne bacteria.

Abstract
1. 서 론
2. 연구 방법
    2.1 조사대상 시설 선정
    2.2 시설별 부유세균 측정
    2.3 DNA추출
    2.4 PCR 증폭반응 및 종분석
    2.5 통계분석
3. 연구결과 및 고찰
    3.1 시설 유형별 군집 다양성 분석
    3.2 시설 유형별 실내/외 세균 군집 다양성 분석
    3.3 주변 환경 특성별 군집 다양성 분석
    3.4 주변 환경 특성별 실내/외 군집 다양성 분석
    3.5 주변 환경특성에 따른 실내외 총 부유세균 농도
4. 결 론
References

• 조은민(서경대학교 이공대학 화학생명공학과) | Eun-Min Cho (Department of Chemical and Biological Engineering, Seokyeong University)
• 이정섭(국립환경과학원 생활환경연구과) | Jung Sub Lee (Environmental Health Research Division, Environmental Health Research Department, National Institute of Environmental Research, Ministry of Environment)
• 조용민(서경대학교 이공대학 화학생명공학과) | Yong Min Cho (Department of Chemical and Biological Engineering, Seokyeong University)
• 이철민(서경대학교 이공대학 화학생명공학과) | Cheol Min Lee (Department of Chemical and Biological Engineering, Seokyeong University) Corresponding author