Analyses on influencing factors of airborne VOCS pollution in taxi cabins

Due to the long time in vehicular cabins, people have high exposure to the airborne volatile organic compounds (VOCS), which will lead to negative effects on human health. In order to analyze the influencing factors of in-car VOCS pollution concentrations, 38 taxis were investigated on the static and closed conditions. The interior air of taxis was collected through activated Tenax adsorption tubes, and the air samples were analyzed with thermally desorbed gas chromatograph. The average concentrations of in-car benzene, toluene, ethylbenzene, xylenes, styrene, butyl acetate, undecane, and total VOCS (TVOC) were 82.7, 212.3, 74.7, 182.3, 24.7, 33.5, 61.3, and 1,441.7 mu g/m(3), respectively. Furthermore, the VOCS and TVOC concentrations increase with the rise of in-car temperature and relative humidity, and decrease with the increase of car age and total mileage. In addition, the VOCS and TVOC concentrations are higher in vehicles with small cabins than in ones with big cabins, and change with different sampling sites and various vehicular grades. Finally, according to the multiple linear regression analysis and hierarchical cluster analysis, car age is the most important factor influencing airborne VOCS and TVOC pollution concentrations in vehicular cabins, followed by interior temperature and total mileage.