Volatile Organic Compounds in Patients' Breath during Conversation

ABSTRACT

Purpose: The protracted coronavirus disease (COVID-19) pandemic has caused an unprecedented global health, social, economic, and psychological crisis. COVID-19 is transmitted via droplets, which include volatile organic compounds (VOCs) emitted by COVID-19 carriers. As a result, medical healthcare workers interacting with COVID-19 patients are at a high risk of infection. In this study, we measured the concentration of total VOCs (TVOCs) in the droplets of patients during conversations. Method(s) Thirty patients aged 20-88 years were enrolled in this study. The amounts of VOCs, formaldehyde (HCHO), and carbon dioxide (CO2) as surrogate parameters for the patient's droplets were measured at a distance of 1 m from the patients under the following conditions 1) no conversation with a mask on, 2) conversation with a mask on, 3) conversation without a mask on, and 4) no conversation without a mask on. Result(s) The average concentrations of TVOCs (mg/m3 ), HCHO (mg/m3 ), and CO2 (ppm) were all the lowest before the masked conversation (1.79 +/- 1.72, 0.25 +/- 0.25, 1193 +/- 516), increased during the masked conversation (1.99 +/- 1.87, 0.29 +/- 0.24, 1288 +/- 555), were the highest during the unmasked conversation (3.10 +/- 1.86, 0.45 +/- 0.28, 1705 +/- 729), and decreased to baseline after the unmasked conversation (1.89 +/- 1.88, 0.26 +/- 0.27, 1191 +/- 518, respectively). Variations in TVOC and HCHO concentrations were positively correlated with patient age (TVOC r = 0.42, p = 0.019 and HCHO r = 0.47, p = 0.008). Conclusion(s) Wearing a mask reduced the VOC concentrations measured during conversations more than when a mask was not worn. Therefore, wearing a mask can reduce the emission of airborne droplet-derived VOCs and thereby reduce the risk of transmission of unknown patient-derived infections. Clinical Trial Registration no The Clinical Trial Registration no (UMIN000039595).Copyright © 2023 Ito et al.