AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA
Abstract View
Effects of Walking Factors on Particle Resuspension via Human Walking
Kyung Sul, Yilin Tian, ANDREA R. FERRO, Clarkson University
Abstract Number: 510 Working Group: Indoor Aerosols
Abstract Resuspension from human walking is known to be a significant source of particles in indoor air. Previous studies have found that there is large person-to-person variability in resuspension rate estimates determined from human participants. However, it is not fully understood how various factors affect particle resuspension. In this study, three walking factors are tested and their effects on resuspension fraction are analyzed. The factors tested are rotational speed of a foot of the device (zero (stomping), slow, medium, and fast rotational walking), pressure beneath the foot on the flooring (low and high), and type of flooring (vinyl and carpet). A mechanical foot apparatus is used as a standardized resuspension mechanism. The apparatus mimics human walking and repeats the same gait cycle with controlling electric actuators. The flooring is seeded with the ultrafine Arizona Test Dust (ATD) and stored in a chamber with controlled temperature and relative humidity for one day. The apparatus resuspends settled particle on the flooring. Size-resolved indoor particle concentrations in the chamber housing the apparatus are measured by an optical particle counter semi-continuously. A mass balance approach is used to calculate resuspension fractions for each condition using a full factorial experimental design. The effects of each factor and two factor interactions are analyzed. The tested factors contribute to the observed person-to-person variability and the strength of the effects depends on the flooring type.