Prevention and Control of Influenza during a Pandemic for All Healthcare Settings

Exposure to Particles Develped by the ANNEX F Working Group, 2008

Figure 2 illustrates the continuum of infectious agent exposure that may impact a susceptible host when touching an infected source or a contaminated environment.

Particles transferred from animate/inanimate objects are considered direct or indirect contact exposure.

Particles transferred through the air (e.g., Aerosols) are primarily considered:

  1. Droplet exposure if the particle size is:
    1. 50-100 µm – face to face range (≤ 2 metres)
    2. 10-50 µm – range from face to face to within the room (overlaps with Airborne – see 2.a. below)
  2. Airborne exposure if the particle size is:
    1. 10-50 µm – range from face to within the room (overlaps with Droplets see 1.b. above)
    2. < 10 µm – range from face to face to beyond the room

The overlapping region with particles from 10-50 µm may constitute either droplet or airborne exposure on the circumstances of the source, host and environment.

Return to Figure 2