Abstract: An apparatus is provided for preventing the spread of air-borne contaminants in a defined space. The apparatus comprises an air flow outlet adjacent to or within the defined space, an air flow inlet adjacent to or within the defined space, and a conduit for transporting air from the air flow inlet to the air flow outlet. An air treatment module is provided within or adjacent the conduit for extracting air-borne contaminants from air transported from the air flow inlet to the air flow outlet. The air flow outlet deposits air into the defined space substantially evenly across an outlet area.