Volatile organic compounds in school buildings with indoor air quality problems

摘要

Indoor air quality (IAQ) has an important contribution to health. Thus, understanding the significance of different factors influencing IAQ and human comfort is of great importance. Volatile organic compounds (VOCs) are often measured as a significant part of IAQ investigations when IAQ is experienced unsatisfactory. The aim of our study was to measure VOC concentrations in four Finnish comprehensive school buildings built or renovated between 2005 and 2009. They were located in the Helsinki Metropolitan area and had mechanical supply and extract ventilation system. Surface materials were plastic floorings and painted walls. Classrooms were furnished with modern school furniture. Occupants had reported significant symptoms or discomfort but no specific cause had been found. VOC sampling (24 samples) and analysis were carried out in six classrooms per school according to the ISO standard 16000-6:2011. Air samples were taken from the central area of an empty, closed classroom in the main working zone at a height of 1.5m. TVOC (total volatile organic compounds) concentrations varied from <10 to 40 pg/m3 (averages per school 12, 9, 8 and 12 pg/m3, respectively). Single VOC concentrations varied from 2 pg/m3 and existing in more than one classroom of all schools were detected: 2-ethyl-l-hexanol, decanal, nonanal, decamethylcyclopentasiloxane, toluene and acetone. Typical sources of the detected VOCs are e.g. different cleaning agents and human cosmetics. In conclusion, measurements showed that the variety and quantity of VOCs was remarkably minor even in the indoor air of schools with reported prolonged IAQ problems.