Systems and methods for reducing airborne contaminants are provided. An air treatment system may include an opening and a filter assembly, a fan coupled to a sanitizing chamber, and an exhaust portion configured to release airflow that has passed through the sanitizing chamber. The fan may be configured to generate an airflow of filtered air through the sanitizing chamber, and the sanitizing chamber may include at least one bend having a total bend angle of at least 90 degrees and at least one straight channel with an array of ultraviolet (UV) light emitting diodes (LEDs) configured to irradiate the airflow with UV radiation. A ratio of a total length of the sanitizing chamber to a cross-sectional area of the sanitizing chamber may be at least 25.