The PM2.5 and PM10 concentrations touched 317 and 458 respectively, putting the city into ‘severe’ category on November 8
A day after Diwali, Delhi's air quality nosedived towards the ‘severe’ category as people violated Supreme Court’s time limit to burst firecrackers, the authorities said.
The PM2.5 (particles in the air with a diameter of less than 2.5 micrometres) and PM10 concentrations touched 317 and 458 respectively, putting the city into 'severe' category on the day, according to Centre-run System of Air Quality Forecasting and Research (SAFAR).
The air quality began dipping on the night of the festival and worsened the next day. The Air Quality Index (AQI) was hovering above 1,000 mark in some areas in Delhi National Capital Region on November 8, according to Delhi Pollution Control Committee (DPCC).
At Patparganj of Delhi NCR, the PM10 concentration reached 1680 µg/m3 at 10.35 am, while PM2.5 touched 1405 µg/m3. At Anand Vihar, the PM10 AQI was 1184 µg/m3 while PM2.5 was 904 µg/m3, DPCC data showed.
The later hours showed a slight improvement in the quality of air in the NCR. However, it continued to be in the 'very poor' to 'severe' zone in most parts of the region.
As per the available data, the air quality started deteriorating rapidly from 7 pm on November 7. The AQI was 281 at 7 pm. It rose to 291 at 8 pm and further deteriorated to 294 at 9 pm and 296 at 10 pm, according to the Central Pollution Control Board (CPCB).
The overall AQI was recorded at 302 at 11 pm, which fell in the very poor category, as per CPCB.
The Supreme Court had allowed bursting of firecrackers from 8 pm to 10 pm only on Diwali and other festivals. It had also allowed manufacture and sale of only "green crackers", which have a low light and sound emission and less harmful chemicals.
The court had asked the police to ensure that banned firecrackers were not sold and said in case of any violation, the station house officer (SHO) of the police station concerned would be held personally liable and it would amount to committing contempt of the court.But despite the apex court order, there were reports of its violation from many areas long after 10 pm.