Influence of Vehicular Frequency on Air Quality of Delhi, India

Abstract Vehicular traffic has registered a phenomenal growth in the last few decades on Delhi roads, their increasing number is a cause of concern for city planners and administrators as they not only deteriorated the quality of environment but has also affected the human health. In this context, we studied the influence of traffic i.e., vehicular frequency on air quality of Delhi. Five sites were selected in four cardinal directions i.e., North, South, East, West and Centre for which data of air pollutants were already available in public domain (DPCC online website). Vehicular frequencies were recorded for Light Motor Vehicle (LMV) and Heavy Motor Vehicle (HMV) for both weekdays and weekends. Correlative analysis were carried out to study the relationship between vehicular frequency and air pollutants. The study showed, East of Delhi had the highest traffic load followed by North, West, South and Centre. We found statistically significant positive correlation between dust pollution, PM10 (r = 0.8) and PM2.5 (r = 0.6) with vehicular frequency while negative association with ozone (r = –0.5). A weak positive correlation was found with NOx (r = 0.2) while weak negative correlation with SO2 (r = –0.3). The study revealed that vehicular exhaust and their movement contribute in deteriorating the air quality of Delhi. Our findings suggest promotion of usage of public transport along with implementation of BS-VI stage vehicles and development of vegetation filters along the roads with native tree species.