The present application provides for air treatment systems for treating air input into a transportation enclosure via at least one input. The air treatment systems include at least two filters that increase in ASHRAE 52.2 Standard MERV parameters in the direction of the flow of air. The filter positioned furthest downstream is at least a parameter 8 MERV ASHRAE Standard 52.2 filter. The air treatment systems include at least one ultraviolet (UV) light emitting device, and UV light reflective material. UV light emitted from the at least one UV light emitting device irradiates at least a portion of the plurality of filters. The plurality of filters, at least one ultraviolet (UV) light emitting device, and UV light reflective material provide a dose of UV light of at least 20 J/m2 to the air input into the transportation enclosure via the at least one input.
