Modeling The Indoor Particulate Concentrations Of Outdoor Origin

Increasing epidemiological studies have reported that particulate air pollution is associated with increased morbidity and mortality even at the generally low levels of air pollution. However, the biological mechanisms have not been understood, i.e. the exact compounds and/or particle size ranges responsible for the health effects have not yet been determined. The indoor environment becomes the most significant exposure potential for particles for two primary reasons. First, people spend most of their time indoors-typically 90%. Second, numerous researches have identified that indoor particulate concentrations of outdoor origin are estimated to be on the same order as outdoor concentrations. Therefore, it is believed that ambient PM indoors has significant effects on human health.Ambient particulate pollution, especially traffic emissions, coal combustion and building-sites dust dispersion, has been paid much attention to by governments and institutes. The public concerns on IAQ are rapidly increasing for its significant role in people's daily life. However, few researches are on indoor particulate pollution, especially the effects of outdoor particulate matter on IAQ.This paper has done a systematic study on this issue. Firstly, it reviewed and analyzed existing research, home and abroad, on indoor particulate pollution of outdoor origin, then pointed out the existing problem and scheduled the methods and content of this research. Later on, it introduced the effects of PM on human health and related standards in several countries. Based on aerodynamic science and experiments results interested, a semi-empirical size-resolved model for predicting the outdoor particulate size distribution indoors was built. The indoor particulate number, area and volume distribution of outdoor origin in five representative building scenarios were then illustrated. The effects of the length, height of building cracks and the pressure difference on the indoor particulate size distribution were analyzed. At last, a simple dynamic model was developed to predict the indoor particulate concentration variation. The effects of several factors including filtration, ventilation and deposition on the indoor concentrations were analyzed and appropriate control strategies were put forward.