Day after Diwali, air quality in Delhi plunged to the severe category with Particulate Matter (PM) 2.5 recorded 1,798 µgm-3, 180 times higher to its safer limit which is 60 µgm-3 as prescribed World Health Organisation ( WHO ) for India.
The overall Air Quality Index ( AQI ) on Sunday settled at 418 µgm-3 at 20:00 hrs under severe category.
This was reported by Central Pollution Control Board ( CPCB ) and System of Air Quality and Weather Forecasting And Research ( SAFAR ), Ministry of Earth Sciences ( MoES ).
According to the agency’s air quality index or AQI, any reading above 100 on a scale of 500 is progressively unsafe for health.
At 08:00 hrs the AQI in Delhi was at 467, indicating severe conditions that pose a risk of respiratory problems. The AQI further deteriorated, standing at 490 at 17:00 hrs.
While the pollution control board uses 24-hour average data, the Ministry of Earth Sciences’ SAFAR, or System of Air Quality and Weather Forecasting And Research, reports real-time figures.
According to SAFAR observatory, the stubble burning contribution was only four percent lowest of the season. “The overall air quality of Delhi is in the Severe category as of today morning as predicted even under zero predicted local load scenario.” “However, the magnitude of PM2.5 within the severe category is found to be more than predicted tend to suggest that significant local additional emissions (probably firecracker related) during yesterday night on already build up stubble fire-related pollutant concentrations lead to such scenario where hourly average concentrations touched more than 1000ug/m3 at midnight on the intervening night of Saturday,”
Citing MeT factors playing crucial role impacting air quality, SAFAR said, boundary layer winds picked up and changed its direction to easterly now which is not favorable for stubble fire-related intrusion.”
“Effective Stubble fire counts (with sufficient potential) estimated from SAFAR-multi-satellite products are significantly reduced to around 350 on Saturday nightin contrast to around 2586,on Friday night.”