Intake Fraction Associated with Indoor Particle Sources: Effects of Source Location and Ventilation Conditions
Donghyun Rim, YESEUL EOM,
Pennsylvania State University Abstract Number: 113
Working Group: Aerosol Exposure
AbstractHuman exposure to indoor aerosols varies with source location and ventilation conditions. Several studies have revealed that indoor airflow and ventilation conditions have notable effects on human exposure. However, there are few studies quantitatively evaluating how human exposure to indoor aerosols varies with source location and ventilation conditions. The objective of this study is to (1) investigate the relationship between intake fraction and ventilation conditions; (2) evaluate the indoor particle concentration distribution in the micro-environment surrounding a human body depending on the source location. Computational fluid dynamics (CFD) simulation was conducted to predict the particulate pollutant transport around a human body in a ventilated room. We investigated transport aerosols of two sizes : (1) 1.0 µm particles, which fall in the fine particle range; and (2) 10 µm particles, which represent respirable coarse particles. Intake fraction around human body was evaluated under two ventilation conditions: (1) mixing and (2) displacement ventilation. The results showed that particle concentration in the breathing zone widely varies with source location and ventilation conditions. Relative to the mixing ventilation, the intake fraction for the displacement ventilation increased notably for particles released from the face region. For the source released from the floor region, spatiotemporal particle concentration gradients were pronounced when particle size was 1 µm with displacement ventilation. The results of this study provide the relationship between ventilation conditions and indoor exposure relative to the concentrations in the breathing zone under representative indoor ventilation conditions.