Delhi Pollution: Not Stubble Burning, Vehicular Emissions Emerge As Top Cause, Says Report
Within Delhi’s local contribution, vehicles are the dominant primary source, accounting for nearly half of all local emissions.
The fingers that pointed to farm fires and stubble burning for being the primary contributor to Delhi's hazardous air quality may have to shift directions.
A study conducted by Centre for Science and Environment or CSE highlighted that the average levels of fine inhalable airborne particles also known as PM2.5 did not go down after the stubble burning ended. On the contrary, the levels intensified in December.
"The study compares the "early winter" months of October and November—a period heavily influenced by farm fires—with the "post-farm fire" period of December, when the impact of stubble burning becomes negligible and finds that the post-stubble burning phase has experienced intense, widespread smog across the NCR – more severe than the stubble burning period", the study stated.
It also offered a reality check on Delhi's air health and said that the problem is more complex than it appears. Between Dec. 1 and Dec. 15, Delhi accounted for only 35% of the PM2.5, while 65% originated from neighboring NCR districts and regions further away.
"The smog is a combination of local emissions, regional inflows, and secondary aerosol formation, requiring coordinated airshed-level action alongside aggressive control of local sources", the study stated.
Rise of these levels was sharpest in Noida, which saw a 38% increase followed by Ballabgarh with 32% increase; Baghpat with 31% rise and finally, Delhi with a 29% increase.
However, the primary cause for the high levels of PM2.5 in Delhi was attributed to vehicular emissions by the analysis, which is based on e real time data available from the current working air quality monitoring stations in the NCR.
"Within Delhi’s local contribution, vehicles are the dominant primary source, accounting for nearly half of all local emissions", the study outlined.
To calculate the contribution of farm stubble fire smoke to Delhi’s air quality the study sourced estimates from the Ministry of Earth Science’s System of Air Quality and Weather Forecasting and Research or SAFAR.
