Simple Holistic Method of Quantifying Local Versus Trans-boundary Air Pollution in NCR-Delhi

This study reports a simple holistic approach to quantifying controllable and uncontrollable particulate load in Delhi-NCR. The concentration of carbonaceous aerosols was measured during a peculiar combination of days that included a major festival, a nationwide public holiday, a weekend, and a couple of working days during September–October 2017. The OC/EC ratio, which serves as an important diagnostic tool for source identification, varied between 1.35 and 1.60 with a mean value of 1.52 indicating fossil fuel combustion as the major source of both OC and EC in the region. The observed trend in AOD values was found to be similar to that in the concentrations of carbonaceous aerosols. An interesting observation was made during the study period wherein all the carbonaceous fractions exhibited a remarkable dip on the public holiday, which was also a non-working weekday. According to our method, around 31.40% of carbonaceous aerosols are emitted from local vehicles and industries (controllable), while the rest 68.60% are emitted from domestic activities and transboundary sources along with windblown resuspensions (uncontrollable). Based on our results, we propose a remedial ‘Work from Home’ policy over the ‘Odd–Even Scheme’ for an observable reduction in particulate load in Delhi-NCR.