Experimental investigation and modelling of human-walking-induced particle resuspension

Abstract

Long-term exposure to airborne particulate matter (PM) indoors can cause adverse health effects to the occupants. Such exposure can be influenced by human-walking-induced particle resuspension (HWIPR). Several factors affecting HWIPR were investigated experimentally. The resuspension rates during walking were calculated based on the mass balance model, and the power law was applied to fit the resuspension rate data. The resuspension rate was further normalized for investigating the effects of various factors on HWIPR. It was found that the normalized resuspension rate of PM10 was about 2.5 times that of PM2.5 for both carpet and wood polyvinyl chloride (PVC). The normalized resuspension rate from carpet was about twice as much as the rates from wood PVC and four times that from vinyl. For both carpet and vinyl, the resuspension rates under the low relative humidity (RH) (41%) were three times that under the medium RH (63%) and 3.5 times that under the high RH (82%). The experimental results suggest that the addition of the mechanical mechanism is critical for HWIPR. Based on the power law relationship, an airborne particle concentration model was developed for HWIPR. The modelled concentration profiles were consistent with the experimentally determined particle concentrations associated with HWIPR. The proposed airborne particle concentration model provides a new way of predicting human exposure to airborne particles due to HWIPR.