Guidelines for Environmental Infection Control in Health-Care Facilities
Already in 2003, in its “Guidelines for Environmental Infection Control in Health-Care Facilities (2003)”, CDC identified particles of 1 to 5 microns (1/1000 to 5/1000 millimetres) as potential means of airborne contamination. In reality, according to the same source these particles contain viable microorganisms; they are protected by a dry secretion layer; keep floating in the air for several hours and travel long distances.
Furthermore, these micro particles travel in a sunlight protected ambient and so it is not exposed to lethal Ultra Violet radiation.
We can ten conclude that it is critical to create negative pressure zones where contaminated patients are present. It is also critical to implement an adequate ventilation system with a high air recycling rate to lower the concentration of microscopic particles to reduce viral load.
Source: Centers for Disease Control and Prevention (CDC)