Current and potential approaches on assessing airflow and particle dispersion in healthcare facilities: a systematic review

Abstract

An indoor environment in a hospital building requires a high indoor air quality (IAQ) to overcome patients' risks of getting wound infections without interrupting the recovery process. However, several problems arose in obtaining a satisfactory IAQ, such as poor ventilation design strategies, insufficient air exchange, improper medical equipment placement and high door opening frequency. This paper presents an overview of various methods used for assessing the IAQ in hospital facilities, especially in an operating room, isolation room, anteroom, postoperative room, inpatient room and dentistry room. This review shows that both experimental and numerical methods demonstrated their advantages in the IAQ assessment. It was revealed that both airflow and particle tracking models could result in different particle dispersion predictions. The model selection should depend on the compatibility of the simulated result with the experimental measurement data. The primary and secondary forces affecting the characteristics of particle dispersion were also discussed in detail. The main contributing forces to the trajectory characteristics of a particle could be attributed to the gravitational force and drag force regardless of particle size. Meanwhile, the additional forces could be considered when there involves temperature gradient, intense light source, submicron particle, etc. The particle size concerned in a healthcare facility should be less than 20 μm as this particle size range showed a closer relationship with the virus load and a higher tendency to remain airborne. Also, further research opportunities that reflect a more realistic approach and improvement in the current assessment approach were proposed.

Keywords: Airflow distribution; Healthcare facilities; Healthcare-associated infection; Numerical simulation; Onsite investigation; Particle dispersion.

Fig. 1

Onsite sampling of a particulate matter (Tan et al. 2022c), b microbial counts (Tan et al. 2022c), c airflow volume (Kamar et al. 2020) and d room pressure difference (Kamar et al. 2020)

Fig. 2

Simplified human manikins and furnishings in a an operating room (Sadrizadeh and Holmberg 2015); b a six-bed isolation room (Hang et al. 2014); c a two-bed ward (Qian et al. 2008); d a single-bed isolation room (Shih et al. 2007); e a single-bed ward (Yin et al. 2011)

Fig. 3

Scanning electron micrograph of skin scales a nearly to be detached from the skin surfaces; b sampled from the air (Clark and de Calcina-Goff 2009)