A Field Study to Characterize Human Emissions in Indoor Air
CHETHANI ATHUKORALA, Suresh Dhaniyala,
Clarkson University Abstract Number: 505
Working Group: Indoor Aerosols
AbstractIn light of the on-going COVID-19 pandemic, there has been an interest in understanding generation, transport, and fate of particles from human emissions. In indoor environment, human-based particle emissions are primarily from breathing and talking. Several research studies have established the characteristics of particle emissions from human activities under controlled lab conditions. Such lab tests use a limited range of air properties, speech phrases, etc. In the real-world, due to the diversity of human speech patterns, ventilation conditions, particle interaction with the surroundings, etc. the effective emission characteristics could be very different from that measured in the lab. To characterize real-world effective human emissions and their contribution to indoor particle transmission, we conducted an experimental study to monitor airborne particles in a highly used, large classroom for a period of 5 months. The temporal change in particle size distributions was determined from measurements made using an Ultra-High Sensitivity Aerosol Spectrometer (UHSAS; DMT, CO; size range: 70 nm – 0.5 μm) and an Aerodynamic Particle Sizer (APS; TSI, MN; size range 0.5 μm – 20 μm). Spatial variation in the concentration of measurements were taken from a network of low-cost optical sensors deployed throughout the room. The measurements were made over a period spanning a change in masking policy from required to optional. Combining the measurement data with an indoor flux-balance model, we obtain one of the first data sets of real-world human emission characteristics that can constrain future efforts to model indoor transmission of airborne diseases.