Vertical variability of volatile organic compound (VOC) levels in ambient air of high-rise apartment buildings with and without occurrence of surface inversion

If there are potential vertical variations in ambient air pollution concentrations, these should be considered when evaluating the exposure of residents living in high-rise apartment buildings. Accordingly, the current study examined this assertion for VOC, while also assessing the potential influence of the atmospheric stability and sampling period on the exposure level of apartment residents. Thirty apartment buildings with 10 or more stories were surveyed in both winter and summer. The atmospheric stability and sampling period were both found to have a potential influence on the variation in the ambient concentrations according to the floor level in the high-rise apartment buildings. Consequently, the current findings emphasize the need to consider these factors in the vertical variation of urban air pollutants when evaluating the exposure of high-rise apartment residents. Moreover, the ambient concentrations of all the target compounds were significantly higher in the winter than in the summer for both the low and high floors. The proportions for the low floors were similar to those for the high floors, plus significant correlations between the target compounds were exhibited for both the low and high floors.