Assessment of fate of respiratory droplets and effectiveness of different air cleaners during outpatient consultation

Abstract

Outpatient departments are open daily to receive patients for consultation. Physicians face a potential risk of infection when diagnosing patients with respiratory infections. This study investigated the fate of droplets exhaled by patient speaking during consultation in a hospital consulting room (CR) using numerical simulations. The accuracy of the numerical methods was verified by on-site bioaerosol dispersion experimental data. Three relative positions (RPs) with various distances between the physician and the patient were considered according to diagnostic needs. Further, the effectiveness of four types of air cleaners was explored. The results showed that the RP significantly affected the fate of the overall droplets in the CR. More than 60 % of the deposited droplets were on floors and tables. In the RP 3 case (0.6 m physician-patient distance), the physician inhaled 11.1 and 13.1 times more viral copies than in the RP 1 and RP 2 cases (1.2 m), respectively. For the droplets deposited on physician's surfaces, they were 8.1 and 5.4 times higher, respectively. The results also showed that regardless of RP, the ceiling-mounted AC was the most effective among the four types of ACs in reducing the droplet number in the CR and virus dose inhaled by the physician.