Quantitative distribution of SVOC substances in a room during and after cleaning measures

Semi-volatile organic compounds (SVOC) in the indoor environment are nowadays receiving increased attention. They can occur in a multitude of products and materials, and their release into air is governed by many parameters. Due to the fact that it is both time-consuming and analytically difficult to measure the usually very low concentrations of SVOC in the field, modelling the fate of these substances has become quite popular. Measured data, especially from realistic environments, is still very scarce. In this study, five different SVOC substances were introduced into two test rooms (one reference room, one intervention room). A wall paint (doped with 3 substances) and pre-cleaned house dust (doped with 2 SVOC substances) were used as sources. The indoor air concentrations of all five substances were monitored over a period of 180 days. After an equilibration phase of 80 days, interventions (air cleaning, vacuum cleaning) were performed in one of the rooms, and the effect on air concentrations was monitored. The interventions included short-term operation of an air purifier and continuous operation over 50 hours. During operation of the air purifier, the air concentration of the target substances in the room was found to be reduced by approximately 50%. Following deactivation of the purifier, however, the concentration swiftly returned to its initial value. This is a strong indication of an evaporation controlled process. The effect of vacuum cleaning on air concentrations was negligible, and even the successive removal of the doped dust in the intervention room during the experiment did not result in a significant decrease of the SVOC concentration compared to the reference room.