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Particle resuspension due to human foot tapping (the landing phase of the foot during the gait cycle) was experimentally studied in a 25 cm (W) × 25 cm (H) × 50 (L) experimental chamber. The foot tapping was modelled using a free rotation toward the floor of a wooden rectangular plate (8 cm (W) × 22 cm (L)). Flooring included ceramic tile, hardwood, PVC tile, vinyl, and two different linoleum samples were utilized. Particle resuspension source strengths were estimated using the mass balance equation. Source strength (emission rates in number of particles per time) ranged from 4 particles/s to 0.05 particles/s. For 0.5–0.65 µm particles, the source strengths in the case of the ceramic tile are 2.5 times greater than those of the PVC tile and eight times greater than those of linoleum flooring. The results show that particles source strengths increase with flooring hardness. However, flooring roughness shows no significant influence on particle resuspension.

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Indoor air quality has become a major concern in recent years due to the adverse effects of poor air quality, caused by the presence of several sources of pollutants, on the building occupants’ health. Particle resuspension has been identified as a major indoor particle matter (PM) source in indoor environments. The present work investigated the human walking-induced PM resuspension in a full-scale laboratory experimental chamber. The PM mass concentration was monitored using a Miniwras Grimm counter. The floor of the test chamber was covered with a tufted synthetic carpet and uniformly loaded with neutralized alumina dust. Using the mass-based balance equation and the well-mixed condition hypothesis, resuspension rates were estimated after 10 min of walking activity. Results show that human walking significantly increases the indoor PM10, PM2.5, PM1, and PM0.1 concentrations. The average estimated PM10, PM2.5, PM1, and PM0.1 resuspension rates were (2.5 ± 0.6) × 10 −1 h −1 , (1.9 ± 0.5) × 10 −2 h −1 , (6.5 ± 0.3) × 10 −3 h −1 , and (4.3 ± 0.3) × 10 −3 h −1 , respectively.

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Human-walking-induced particle resuspension in indoor environments is believed to be an important source of particulate matter. Aerodynamic disturbance generated by the human foot during a gait cycle are the main driver for particle detachment and dispersion in the room. In this work, the hot-wire anemometry technique was employed to investigate the airflow generated by one phase of the human gait cycle: the foot tapping. This phase was simulated by a mechanical simulator that consists of a wooden rectangular 25 × 8 × 1.2 cm plate, and a servomotor that allows downward and upward rotations of the plate with a constant velocity. A correction procedure based on the hot-wire velocity measurements and the analytical solution of Falkner–Skan has been derived to correct the hot-wire readings in the near-wall region. Results show a sharp increase of airflow velocity in front of the simulator after the simulator rotation. Transverse hot-wire measurements downstream of the simulator show that the profile of the maximal velocities reaches a peak at a distance y = 8 × 10−3 m from the wall. The expulsed air from the volume under the simulator propagates downstream from the foot to reach near zero velocity values at 0.15 m away from the top of the simulator.