Urban Air Quality Responses to Reduced Anthropogenic Activities during Lockdown Periods in Lucknow, India

Air pollution remains a major environmental and public health concern in rapidly urbanising Indian cities. Lucknow, the capital of Uttar Pradesh, has experienced persistently poor air quality due to increasing population, vehicular density and urban activities. This study examines air quality levels before, during and after lockdown periods, focusing on changes associated with reduced anthropogenic activities rather than the COVID-19 pandemic itself. Secondary data on PM₁₀, PM₂.₅, NO₂, SO₂ and Air Quality Index (AQI) were obtained from the Uttar Pradesh Pollution Control Board for the period 2019–2025. Results show that during the lockdown period, mean PM₁₀ and PM₂.₅ concentrations declined from approximately 190–260 µg/m³ to 135 µg/m³ and 60–80 µg/m³ to 45 µg/m³, respectively, though values still exceeded the WHO Air Quality Guidelines (2021). Post-lockdown periods recorded sharp increases, particularly in NO₂, reflecting renewed traffic and urban activity. The findings indicate that observed air-quality improvements were temporary and closely linked to reduced human activities, highlighting the need for sustained emission-control strategies.