Abstract
Compared to passenger cars, there have been fewer studies on the on-board environment of large buses and fewer studies on infection control and air quality. The analysis of odors emitted from the air conditioning equipment and atmosphere of large buses has been difficult because it requires multifaceted studies that include factors directly related to passenger safety, such as micro-organisms and aerosols. This study describes the process and results of evaluating the odor of air collected from the air conditioning vents of buses using sensory evaluation and instrumental analysis. Odor sensory test and instrumental analysis combining odor-sniffing gas chromatograph: thermal desorption (TD), gas chromatograph time-of-flight mass spectrometer (GC-TOFMS) and sniffing with odor intensity device (OID) were used. The results showed that sniffing inside the bus was unsuitable for sensory evaluation due to the large influence of the panel's body odor, and that this influence could be reduced by collecting odor samples in a bag and sniffing them outside the bus. We then found odor substances that were thought to emanate from human body and bus interior materials by sniffing ourselves with OID. As a result, this screening method with TD-GC-OID-TOFMS enabled the detection and estimation of the substances and sources that have an impact on the odor inside of buses.
