The present invention provides an apparatus 1 for the treatment of air comprising a low power corona discharge ozone generator 5,6 inside a chamber 9 having an inlet 2 and an outlet 7, and at least one air flow impeller 3 for inducing a flow of air through the chamber 9. The ozone generator 5,6 is formed and arranged for generating a restricted concentration of ozone, within an inactivating zone 10 contained within the chamber 9, through which the air flow is passed. The restricted concentration is sufficient to inactivate airborne pollutant material entrained in the air flow, yet decays sufficiently outside the inactivating zone so that the concentration of ozone in the cleaned air expelled from the apparatus 1 is at a physiologically acceptable level without the use of an ozone decomposition catalyzer.