Assessing the Influence of Hydration Levels on Respiratory Aerosol Production

Mahender Singh Rawat, Dinushani Senarathna, Byron D. Erath, Sumona Mondal, Sarah K. Sirsat, ANDREA FERRO, Clarkson University

     Abstract Number: 446
     Working Group: Indoor Aerosols

Abstract
Reported emission rates of respiratory aerosols from speaking, shouting, singing, coughing, and breathing vary widely in the literature. Several factors, such as loudness, frequency, and age, have been shown to affect respiratory particle emissions rates. However, these factors alone are not sufficient to predict emission rates. Previous work has shown dehydration reduces saliva and respiratory tract lining fluid production and changes the rheology of these fluids. Hence, it is hypothesized that hydration levels influence respiratory aerosol production. This is evaluated by measuring respiratory aerosol emissions from participants in both well-hydrated and dehydrated conditions. Participants were asked to phonate into a funnel connected to an aerodynamic particle sizer (APS) to determine the aerosol emission rate and size distribution. To measure the expiratory flow rate, participants were asked to phonate the same vocal sequences into a Vyntus Hans Rudolf mask kit connected to a spirometer (iWorx TA Model 220). The participants performed several vocal exercises, in random order, including the open vowel /a/, forced breathing, and running speech. The preliminary results showed that the hydrated participants emitted 35% more particles by number than the dehydrated participants during the vocal exercises. Our initial findings are consistent with the hypothesis that participants who are well-hydrated tend to have higher aerosol emission rates compared to when they are dehydrated.