In China, nitrogen dioxide (NO2) has emerged as a major pollutant in the atmosphereAtmosphere due to rising urbanizationUrbanization and industrialization. The present study (1) from 2015 to 2020 in China distinguished long-term NO2 ascribed health metric; (2) evaluate NO2 concentration trends; (3) comparison of NO2 levels before and at the time of COVID-19COVID-19 pandemic. The research utilizes data from national air quality monitoring networks and health impact assessments to elucidate the trends and impacts of NO2 pollution. Results indicate a general decline in NO2 concentrations across the majority of Chinese cities, reflecting the effects of governmental pollution controlPollution control measures. Notably, a substantial reduction in NO2 levels was observed at the time of COVID-19 situation, ascribed to the strict lockdowns and significant depletion in vehicular and industrial activities imposed by the Chinese government. This temporary improvement in air quality during the pandemic underscores the potential effectiveness of stringent pollution control measures and provides a unique natural experiment for evaluating such interventions. Additionally, the study reveals spatial disparities in NO2 concentration reductions, with some regions experiencing more pronounced declines than others, highlighting the need for region-specific strategies. By providing a detailed analysis of NO2 pollution trends and health impacts over a significant period, the research glimpses to the understanding of urban air quality dynamics in China and informs the development of more effective environmental and public health policies. Furthermore, advancements in AIArtificial Intelligence (AI) and ML techniques can be instrumental in enhancing the monitoring and analysis of NO2 pollution. These technologies enable accurate predictions of pollution trends, real-time detection of emissionEmission hotspots, and effective modelling of health impacts, aiding in the formulation of targeted and data-driven environmental policies.