Aerosol particles of respirable size are exhaled when individuals breathe, speak and sing and can transmit respiratory pathogens between infected and susceptible individuals. The COVID-19 pandemic has brought into focus the need to improve the quantification of the particle number and mass exhalation rates as one route to provide estimates of viral shedding and the potential risk of transmission of viruses. Most previous studies have reported the number and mass concentrations of aerosol particles in an exhaled plume. We provide a robust assessment of the absolute particle number and mass exhalation rates from measurements of minute ventilation using a non-invasive Vyntus Hans Rudolf mask kit with straps housing a rotating vane spirometer along with measurements of the exhaled particle number concentrations and size distributions. Specifically, we report comparisons of the number and mass exhalation rates for children (12–14 years old) and adults (19–72 years old) when breathing, speaking and singing, which indicate that child and adult cohorts generate similar amounts of aerosol when performing the same activity. Mass exhalation rates are typically 0.002–0.02 ng s
−1
from breathing, 0.07–0.2 ng s
−1
from speaking (at 70–80 dBA) and 0.1–0.7 ng s
−1
from singing (at 70–80 dBA). The aerosol exhalation rate increases with increasing sound volume for both children and adults when both speaking and singing.
<p>The importance of bio-aerosols across the earth system has been known for some time. With the unfortunate situation arising from the COVID19 pandemic, attention has turned to appropriate detection technologies that could be used to better understand the contribution of aerosols generated from the lung in various settings. In this project, the wideband Integrated Bioaerosol Sensor (WIBS-NEO) was deployed in a zero-background clinical environment which permitted the aerosols measured to be directly ascribed to specific vocalisations undertaken. The fluorescent signatures of expelled aerosol from a variety of human participants were captured during individual speech and language therapy activities (speaking, humming, sustained phonation, fricatives, projection, and tongue trills). In this presentation we present the varying fluorescent signatures and particle morphologies.</p><p>Furthermore, millions across the UK have now adopted face coverings into their day to day lives with one of the most widely adopted and commonplace being the disposable surgical face mask. Yet, questions still remain as to what types of vocalisations produce the most aerosols and the efficacy of the face mask in reducing transmission. To supplement this, measurements with the WIBS-NEO were conducted where participants did not wear a mask, and then subsequently repeated wearing a surgical mask. The fluorescent intensity, concentration (cm<sup>3</sup>), size (um), and asphericity were then compared for each activity with and without a mask.</p><p>&#160;</p><p><strong>WIBS-NEO information:</strong></p><p>https://www.dropletmeasurement.com/product/wideband-integrated-bioaerosol-sensor/</p><p><strong>Example paper using the WIBS:</strong></p><p>E.Toprak and M. Schnaiter, <em>Atmos. Chem. Phys.</em>, 2013, <strong>13</strong>, 225&#8211;243.</p><p>&#160;</p>
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