Fluctuation of Nighttime Ground Level Ozone Due to Artificial Light

Ultraviolet (UV) radiation creates ground-level ozone (O3) during the day and is subsequently eliminated by nitrogen oxides at night. However, excessive artificial light use, those results in light pollution, may interfere with the chemistry of ground-level O3 at night by supplying enough energy to start that creation. Therefore, this study aims to identify the effect of artificial light on nighttime ground-level ozone production. Minute average O3 and NO2 concentrations with light illumination were measured in two study sites at the USM School of Civil Engineering and its Main Campus. Results of this study suggested that in low-light illumination conditions, no conversions between NO2 to O3 were governed due to low-light energy that was unable to break NO2 bonds. Thus, there are no changes in O3 concentration trends in the School of Civil Engineering. However, in high-light illumination conditions such as in USM Main Campus, O3 fluctuated negatively with NO2 concentrations, and potential conversions were governed.