Effect of Barrier on Spatial Distribution of Simulated Respiratory Particles in a Room
MARIAH GNEGY, Chase Gohlke, Linsey Marr,
Virginia Tech Abstract Number: 97
Working Group: Bioaerosols
AbstractIn response to the COVID-19 pandemic, the CDC issued workplace guidelines to protect workers when social distancing (≥ 6 feet) is not feasible; a hazard control recommendation is to install physical barriers. In the absence of other control measures, barriers may not provide adequate protection to individuals within that space due to altered airflow induced by the barrier. The objective of this study was to quantify the impact of the barrier on the spatial distribution of different sized particles released from a nebulizer that simulated respiratory emissions produced by speaking. We constructed 108 passive sampling locations in a room and nebulized fluorescent particles of relevant sizes both with and without a barrier (located 18 inches from the nebulizer outlet) to observe the differences in particle distributions. We counted the number of particles deposited on slides at the sampling locations. The presence of a barrier resulted in a significant increase in the number of 0.5 µm particles on the side of the barrier where the nebulizer was located; there was also a significant increase of 0.5 µm particles on the sides of the barrier, indicating that the air that moved around the barrier transported these particles. At distances of 14 and 19 feet from the nebulizer, the barrier resulted in a higher number of 0.5 µm particles, implying that the barrier can lead to increased exposure for those situated far away from a barrier. There were no observable differences in the distribution of 6-µm particles within the room with vs. without the barrier. Lastly, 10 and 20 µm particles were too large to be influenced by the barrier. These results imply in the absence of other control measures, barriers may not serve as adequate protection to others in the room, depending on their location relative to the barrier.