An investigation of formaldehyde concentration in residences and the development of a model for the prediction of its emission rates

Abstract

Indoor air pollution caused by formaldehyde associated with building materials imposes a variety of acute and chronic adverse effects on people's health. The aim of this research is to investigate the concentrations of formaldehyde in residences and develop emission rate prediction model in residential buildings. On-site measurements including the indoor and outdoor concentrations of formaldehyde and CO2 were carried out in 42 urban residences in Chongqing. The people occupancy schedule in different functional rooms was obtained by observing the change in CO2 concentration. A robust model for the estimation of formaldehyde emission rates using CO2 as the tracer gas; associated with a Monte-Carlo simulation of occupant activities and the characteristics of residences; has been developed. It is revealed that the mean indoor formaldehyde concentration was 30.12 μg/m3, which was slightly higher than the outdoor concentration of 27.80 μg/m3. The emission rates of 61.82 ± 52.39 and 49.69 ± 42.13μg/h/m2 (mean ± SD) during the daytime and nighttime, respectively with a daily average of 57.20 ± 48.79μg/h/m2. The significant contribution to indoor formaldehyde concentration was from indoor sources. Indoor formaldehyde source control is suggested to be an efficient way to control the indoor concentration.