Spatial variation of VOCs and inorganic pollutants in a university building

Özet

Indoor concentrations of 34 volatile organic compounds (VOCs), sulfur dioxide (SO2), nitrogen dioxide(NO2) and ozone (O3) were measured at 32 sampling points in classes, offices and hallways of theEnvironmental Engineering Department (ENVE) in the Middle East Technical University (METU) inAnkara. Outdoor samples were also collected around the department during the sampling campaigns.Two passive sampling campaigns, one in summer and the other one in winter, were conducted. Indoorconcentrations of most pollutants were higher than their outdoor concentrations owing to the presenceof indoor sources. The notable exception to this general pattern is O3. The average indoor/outdoorconcentration ratio (I/O) was 10.9 in winter and 3.7 in summer. For most of the VOCs, the winter concentrations were higher than their summer concentrations due to more effective ventilation of thebuilding and variation of emissions during summer months. Compounds with higher concentrations inthe summer samples were the ones that were strongly affected by solvent evaporation in laboratories.