Investigation of indoor air quality in a residence using natural materials

Indoor air quality (IAQ) in a house using building materials with low chemical emission wasinvestigated for 8 months. Indoor air concentration, emission rate of aldehydes and VOCsfrom floor and wall, air change rate, temperature and relative humidity were measured toevaluate the IAQ of the house. Air change rate was measured by two methods. Indoor airconcentration and emission rate from building materials were measured at differentconstruction phases (before and after completion) and after being occupied. A questionnairewas used to examine the influence of lifestyle on IAQ. The values of emission rate offoundation materials were larger than that of interior materials. Formaldehyde concentrationswere under 100 g/m3 (the largest value was 52 g/m3), which is below the guideline ofWHO and Japanese Ministry, but TVOC concentrations measured after 3 months occupancywere above 1000 g/m3. Major chemical substances in this house were different from thosemeasured in conventional houses.