small particles of moisture (e.g., spatter) that may be generated when a person coughs or sneezes or when water is converted to a fine mist by an aerator or shower head. Intermediate in size between drops and droplet nuclei, these particles, although they may still contain infectious microorganisms, tend to quickly settle out from the air so that any risk of disease transmission is generally limited to persons in close proximity to the droplet source.

Particles consisting of dried mucus in which microorganisms are embedded.

tiny drops of water.