Volatile organic compound concentrations in newly built apartment buildings during pre- and post-occupancy stages

Abstract

This study provides updated concentrations of 30 selected volatile organic compounds (VOCs) of indoor and outdoor air in new residential buildings before and after inhabitants moved in. During both the pre- and post-occupancy stages, toluene was the most abundant indoor VOC and, unlike other target VOCs, the indoor concentrations of six chlorinated compounds did not differ significantly from the outdoor concentrations, indicating the absence of any significant indoor source(s). The indoor concentrations of certain VOCs were significantly higher for the one-month post-occupancy stage than the pre-occupancy stage, which was likely attributable to emissions from furiture and household products used by inhabitants after moving in, as well as building finishing materials. The indoor concentrations of individual (excluding naphthalene and six chlorinated VOCs) and total VOCs revealed a decreasing tendency over the 2-y follow-up period. Moreover, there was an initial rapid decrease in indoor VOC concentrations followed by a somewhat slower decrease over the 2-y follow-up period, reflecting a multi-exponential decay model for VOCs. The measured indoor VOC concentrations and their matched measurement times were well fit to exponential models. During the pre-occupancy stage, aromatic hydrocarbons exhibited the highest emission rate. In contrast, terpenes showed the highest emission rate during the post-occupancy stages. The levels of VOCs determined in this study are necessary for establishment of effective VOC control strategies in new residential buildings and linking exposure to the health risk posed to inhabitants.