It is generally accepted that human skin is a source of bacterial dispersal and the most common cause of infection in sensitive indoor surgical environments such as operating rooms (ORs). Airborne particles carrying microorganisms are dispersed from the whole body, but with different release rates. Previous studies show that particle dispersal was occurring mainly from the lower part of the body, especially from the perineal area. Whether the release position influences particle distribution in the surgical area has not been well known.

In this paper, two different particle launch positions, one from the head and neck and one from the perineum region and feet, were compared. Computational fluid dynamics (CFD) technique was employed to solve the governing equations for airflow and particle distribution.

The results indicate that particles released from the lower part of the body might easily rise by buoyancy forces. Several vortices generated by the main OR ventilation system may also bring particles from the lower part of the OR to the surgical area and increase the risk of infection.