Abstract: The combined light source and air purifier unit includes a body (11) and a centrifugal fan (12) with rearwardly facing blades (20) run at low speed and mounted by the body with its axis upright and a central intake (17) through which air containing contaminants is drawn from a target zone (80) below the unit. A light source (14) mounted within a peripheral projecting skirt (75) is located radially outside the intake (17) of the centrifugal fan (12) so as not to obstruct the flow of intake air. A filter (13) extends circumferentially around the fan (12) and an air discharge (60) includes a smoothly curved flow deflecting means (62) provided by the body (11) to deflect air flowing outwardly from the fan in an upwards direction at about 45° or less to the vertical.