Air quality assessment in schools - quantification of volatile organic compounds

Indoor air quality is an important issue with major consequences on occupants' health as nowadays more time is spend inside buildings. Volatile organic compounds (VOCs) are important air pollutants because of their major variety and complexity. Their main composition is carbon and hydrogen associated to halogens, oxygen, phosphorus, silicon or nitrogen. They are characterized by evaporating at room temperature due to their weak intermolecular forces. To evaluate the concentration and potential effects in children, an evaluation of VOCs was carried out in three schools of the region of Viseu. In each school, two classrooms were selected and two measurement periods were defined. The quantification of VOCs was done according to OSHAs' methods. It was used an active sampling method to collect the samples in carbon tubes that afterwards were treated with CS2 solvent. The quantification was done by gas chromatography with a mass detector. Air temperature, relative humidity and CO2 concentration were also monitored. Concerning these parameters, CO2 showed concentrations above the threshold value. The most common VOC detected in the classrooms was Limonene, however in concentrations bellow the usual range inside buildings. In some classrooms, Toluene and Tetradecane were also quantified, with concentrations above 0.6 mg/m(3), which is the protection threshold for total VOCs indoors.