Study of Vehicular Pollution during Odd-Even Days in Delhi

Abstract

The air pollution levels in Delhi are quite high and situation is worsening with continuous increase in number of vehicles in the city, ultimately affecting the health of residents of Delhi. To control the emissions due to vehicles, the government of Delhi, in January 2016 implemented odd-even scheme on Delhi roads for 15 days, i.e. from 1st to 15th January 2016. As per this scheme, on odd days, only vehicles having last digit as an odd number on their number plates will be permitted and vice versa, though few exemptions were also made. To study the impact of this scheme on pollution levels in Delhi, air quality data of concentration of air pollutants at various locations in Delhi have obtained from CPCB website, namely RK Puram, , Mandir Marg and Punjabi Bagh. Daily air quality index (AQI) of PM₁₀, PM_2.5, SO₂, NO₂, O₃ and NH₃ has been calculated at these locations. It is found that PM₁₀ and PM_2.5 are the main contributors to the degrading of air quality in Delhi. The results of air quality index for almost all locations revealed that the pollution levels were high during the implementation period of odd-even scheme as compared to December 2015. After 15 January, again there was some drop in pollution levels. The reason for high pollution levels, during those 15 days was found due to the meteorological conditions, mainly drop in daily temperature and low wind speeds as observed from IMD data for Delhi as compared to that of December 2015. Whereas after 15th Jan there was again a drop in daily average temperature but wind speed was high; this improved the conditions leading to better dispersion of pollutants and overall improvement in air quality.