The AIRMEX study - VOC measurements in public buildings and schools/kindergartens in eleven European cities: Statistical analysis of the data

Indoor and outdoor air concentrations as well as personal exposure concentrations of volatile organic compounds (VOCs) have been measured during 2003-2008 in public buildings, schools, kindergartens and private homes in eleven cities over Europe covering geographic areas in north, central and south Europe during different seasons within the frame of the AIRMEX (European Indoor Air Monitoring and Exposure assessment) study. A database is presented containing the results for 23 VOCs based upon approximately 1000 samples taken from 182 different working environments (offices, classrooms, waiting halls) in public buildings, schools and kindergartens, from 103 private homeplaces and from adult volunteers (148 samples). The statistical analysis of the data demonstrated that sources in the indoor environment are prevailing for most of the investigated VOCs with indoor/outdoor (I/O) concentration ratios following the order: hexanal approximate to D-limonene >> formaldehyde > acetone > 1-butoxy-2-propanol > acetaldehyde > propanal > 1-butanol > n-undecane > methylcyclohexane > ndodecane. For aromatic hydrocarbons the main impact was shown to be penetration from outdoor air as indicated by I/O ratios near one and is characterised by significantly higher indoor as well as outdoor concentrations in the south of Europe with respect to the north. For the terpenes, the lowest indoor concentrations were measured during the warm season, which may be explained by higher ventilation rates and reactions with ozone penetrated from outdoor air. (C) 2011 Elsevier Ltd. All rights reserved.