The effects of wooden building materials on the indoor air quality of houses

Abstract

Exposure to indoor chemical air pollutants has a great impact on our health because we spend most of our time inside buildings. Pollutant exposure levels inside buildings are likely due to pollutants from both indoor and outdoor sources. As a natural, biological material, wood emits various organic chemical substances, mostly volatile organic compounds (VOCs), very volatile organic compounds (VVOCs) and formaldehyde. When such emissions occur in indoor spaces, concentrations of these substances are higher than concentrations outdoors. Consequently, the level of emissions from building materials is of relevance in relation to their possible health effects. The current work shows the measurements of the indoor air concentration in a passive, low-energy, wooden, light frame house. Concentrations of volatile organic compounds (VOC) and formaldehyde were measured and compared and with the current international regulations of air pollutants. Six measurements were taken throughout one year. An active sampling device was used on the site. The results of the measurements showed the changing concentrations of air pollutants. Concentrations of 180 components were determined according to standards ISO 16000-6:2004. During the field measurements we detected the presence of formaldehyde (34μg/m3), BTX (35.51μg/m3

), and some materials in the terpene family, limonene (64.7μg/m3

), and alpha-pinene

(297μg/m3 ), in the indoor air. The concentration of the detected TVOC (Total Volatile Organic Compounds) was 2150μg/m3 , which does not significantly differ from European average values. We determined the health risk of all measured substances according to the German standard using the Lowest Concentration of Interest (LCI) analysis. The conclusion of the present case study is that the total volatile organic compounds (TVOC) of the indoor air during the one-year measurements had been changed only slightly and they did not pose a health risk. The concentration of the TVOC was influenced by indoor temperature, indoor relative humidity and air exchange rate. Human activities and the furniture had the greatest impacts on the concentrations. The rate of the wooden clothing in each room had a great influence on the concentrations of alpha-pinene and 3-carene.