A comprehensive indoor air quality study of public transport buses spanning thirteen months of data collection involving the monitoring and measurement of multiple indoor gaseous pollutants and ultra-fine particulates was conducted in Toledo, OH. Variation of all the pollutants studied were dependent on the route traveled, and additionally carbon dioxide was also found to be greatly dependent on passenger ridership. The most prominent increase in the pollutant concentrations were seen during the morning pullout and in periods of highest traffic around 9 am. The indoor pollutant concentrations were found to be within the error range in both the bio-diesel (B20) and ultra low sulfur diesel (ULSD) buses suggesting minimal effect of fuel on the indoor air. The air quality regression models developed using a combination of vehicular, traffic, and meteorological variables explain approximately 68-81% of the hourly indoor pollutant concentrations.
Abstract