Wildfires are widely known to increase atmospheric pollutant concentrations, deteriorating air quality. However, several studies have reported that wildfires can also reduce the concentrations of certain gaseous species. This study investigated the impacts of smoke plumes from wildfires that occurred in late July 2014 in Siberia, Russia, on downwind gaseous pollutants such as carbon monoxide (CO), nitrogen oxides (NOx), volatile organic compounds (VOCs), and ozone (O3). The Community Multi-scale Air Quality model was employed for air quality simulations, and wildfire emissions were obtained from the Fire INventory from the National Center for Atmospheric Research. Wildfire-induced CO, VOCs, and O3 were transported to Northeast China (NEC), the Yellow Sea (YS), and the Korean Peninsula (KP), resulting in elevated pollutant levels in these downwind regions. Interestingly, despite the transport of plumes, surface-level NOx concentrations over NEC, YS, and KP even decreased. Such reductions were not evident near the Siberian source areas but became apparent after the plumes reached the NEC region. In these regions, NO was removed through reactions with wildfire-induced VOCs (84.54 %) and NO3 radicals (13.18 %), while NO2 was primarily depleted by O3 (90.08 %) or converted into organic nitrates via reactions with VOCs (9.92 %). We found that the observed reductions in NOx concentrations were attributable to anthropogenic sources, as the reduction patterns varied depending on the level of anthropogenic NOx emissions in the sensitivity experiments. These results suggest that wildfire-driven NOx concentration changes in downwind regions cannot be fully explained by wildfire emissions alone. This study underscores the importance of accurately characterizing anthropogenic emission sources in regions affected by smoke plume transport to predict changes in gaseous pollutant concentrations following wildfire events. We expect that this study will enhance future wildfire-related research by improving the prediction of the spatial distribution and atmospheric behavior of gaseous pollutants.