An apparatus for removing contaminants from air, including nitrogen oxides, carbon monoxide, carbon dioxide, and sulphur dioxide. In one of the chambers of a multi-chambered enclosure, polluted inlet air is exposed to one or more first light sources emitting light at wavelengths less than or equal to 242.3 nm to cause dissociation of contaminant molecules, creating ozone plus remaining atoms. The remaining atoms are largely filtered by activated charcoal filters having an appropriate thickness which is sized to achieve suitable dwell times, and which also serves as an oxygen rich medium permitting the ozone generated to undergo atomic rearrangement, whereby ozone molecules (O3) and atomic oxygen atoms (O) form oxygen molecules (O2). In another downstream chamber, the air flow is exposed to one or more second light sources emitting light at wavelengths greater than 242.3 nm but less than 280 nm, causing conversion of remaining ozone into oxygen molecules.