Investigation of NOx and related secondary pollutants at Anand Vihar, one of the most polluted area of Delhi

Abstract

This research investigates the influence of meteorological parameters on NOx concentrations, particularly NO2, and related secondary & primary pollutants at the Anand Vihar interstate bus terminal in Delhi. Statistical analysis of long-term data (2016–2021) examines seasonal, weekly, and daily variations in NOx and other pollutants. Temperature and relative humidity show a significant impact on NO2 levels. Seasonal patterns reveal lower concentrations during the monsoon season and higher concentrations in winter and post-monsoon periods, except for ozone. The year 2018 stands out as the most polluted for NO2. Vehicular activities directly influence pollution, evident through reduced NO2 and benzene levels during the COVID-19 lockdown. The Planetary Boundary Layer (PBL) height plays a critical role, with lower PBL heights associated with increased NO2 concentrations. Electric Vehicles (EVs) have a positive effect on reducing NO2 pollution. Comparison with a less transportation-impacted site highlights higher NO2 concentrations in areas with heavy vehicular traffic, emphasizing the need for pollution control measures and sustainable transportation. Correlation and regression analyses confirm the interdependence between PM and NO emissions, underscoring the significance of addressing vehicular emissions for effective pollution mitigation. This study provides valuable insights into the intricate relationship between meteorological parameters, vehicular emissions, and NOx concentrations.