Dust is a part of the Atmos Aspect, which is made by combining Heat and Land.
This is an active fysa. Dust allows users to sense decay within 100 meters (109 yards). They can manipulate particles, including dust and sand, within 10 meters (11 yards). Lastly, they can accelerate or pause the decay of an already decaying object while they are nearby.
You must have already learned either Heat or Land in order to learn this ability.