The dust from asbestos can be an aerodynamic particle thatis carried in very low wind velocities. Settling time is dependent on many factors. Resuspension of particles into the breathing zone can occur with disturbances such as sweeping or vacuuming, thus wet pick-up methods and HEPA are recommended. This answer is as ambiguous as your question. Please provide more details.

It would be dust made airborne by the tearing up of backing of old sheet vinyl.