This study investigates the indoor air quality conditions of the total of 52 buses depend on seasons, time and others. We evaluated the CO₂and PM10, the controlled parameters in express buses by Ministry of Environment and VOCs and HCHO, the non-controlled parameters. The CO₂concentration during peak commute times was 38.5% in summer and 15.4% in autumn, which are higher than the normal. But, PM10 concentration was influenced by the outside air not number of passengers. The concentration of VOCs were not related with other parameters such as number of passengers, seasons, and driving time. And then, the formaldehyde concentration was not related with seasons as it showed little difference between summer and autumn.

Abstract
 1. 서 론
 2. 연구방법
  2.1 연구대상 및 조사기간
  2.2 대중교통 차량별 시료 측정 방법
 3. 결과 및 고찰
  3.1 규제물질
  3.2 미규제 물질
 4. 결 론
 References

• 안선민(평택대학교 생활 및 산업 환경 R&D센터) | Sun-Min An (Life & Industry Environmental R&D Center in Pyeongtaek University)
• 이정훈(평택대학교 생활 및 산업 환경 R&D센터) | Jeong-Hun Lee (Life & Industry Environmental R&D Center in Pyeongtaek University)
• 윤승욱((주)푸른환경산업연구소R&D센터) | Seung-Wook Yoon (R&D Center, Green Environment Industrial Institute)
• 김호현(평택대학교 생활 및 산업 환경 R&D센터, 평택대학교 ICT융합학부 ICT환경융합전공) | Ho-Hyun Kim (Life & Industry Environmental R&D Center in Pyeongtaek University, Department of Information, Communication and Technology Convergence, ICT Environment Convergence, Pyeongtaek University) Corresponding author