Concentrations of volatile organic compounds in the passenger side and theback seat of automobiles

The in-vehicle volatile organic compound (VOC) concentrations during commut es have previously been measured in only one single interior sampling locat ion, considering a sample collected in the single interior location as repr esentative of overall VOC concentrations within an automobile. The present study evaluated if the potential differences in VOC concentrations occur in the automobiles' interior during idling and commuting under different driv ing conditions associated with the use of air cleaning devices (ACDs) and i nterior fan. The experiments were conducted under the low ventilation condi tion with the windows and the vent closed and the fan off. The difference o f VOC concentrations between passenger side and back seat during idling was small. The variability of VOC concentrations with location inside automobi les while commuting was not significant at p<0.05, regardless of the use of ACDs and/or the interior fan, while inter-vehicle variability was signific ant at p<0.05. In addition, currently available ACDs equipped with activate d carbon filters in Korea were ineffective at removing VOCs from the interi or of automobiles. The concentrations of the two lightest ones of the targe t compounds, benzene and toluene, were significantly higher inside two vehi cles than in the roadway air at p<0.05, while the in-vehicle and roadway co ncentrations of the other target compounds did not differ significantly at p<0.05 for both vehicles. The concentrations of all target VOCs, except ben zene, were significantly higher (p<0.05) in the interior of older car than of newer car. Median in-vehicle concentrations of benzene, toluene, ethylbe nzene, p-xylene, m-xylene, and o-xylene were 38.3, 107, 9.2, 7.8, 16.9, and 10.7 mu g/m(3), respectively.