Characteristics of exposure and health risk air pollutants in public buses in Korea.

Abstract

The objective of this study was to estimate the concentrations of indoor air pollutants in unregulated public transport means in Korea and to determine the factors affecting the air quality as well as to assess the harmful effects of indoor air pollutants on the health of passengers. The correlation between particulate matter (PM10) and number of passengers on intra-city buses, express buses, town shuttle buses, or rural buses was insignificant whether it was during rush hours or non-rush hours. In regard to PM10 on express buses, there was no case where the standard limit was exceeded during the winter and summer seasons. In winter, however, the average concentration of PM10 increased by the travel distance. In regard to CO2, there was a statistically significant correlation (p < 0.05) between CO2 concentrations and the number of passengers, owing to human respiration. Unlike the case of PM10, there was a difference between rush hours and non-rush hours. Regarding volatile organic compounds (VOCs) and aldehydes, the values were high among recently manufactured vehicles regardless of bus types. The standard limit was exceeded during the summer season, which seemed to be related to the temperature and humidity in both indoor and outdoor. The results of this study indicate that the excess mortality resulting from PM10 was as high as the safety margin during both non-rush hours and rush hours among all unregulated public transportation means. The excess cancer risk and non-cancer risk of VOCs and aldehydes were as high as the safety margin during both non-rush hours and rush hours.