Worst Nov for Delhi’s air: 11 ‘severe’ pollution days
On Saturday, the average air quality index again rose to severe levels (402) for the 11th day this month, breaking the record of 10 dangerous air days in November 2016, CPCB data showed.
November has been the cruellest month this year in Delhi, with 11 days showing severely polluted air on the monitors of Central Pollution Control Board (CPCB), the highest since detailed records have been maintained by the pollution watchdog, with three days for the month still to go.
On Saturday, the average air quality index again rose to severe levels (402) for the 11th day this month, breaking the record of 10 dangerous air days in November 2016, CPCB data showed. The alarming situation in 2016 had led to the administration declaring an air emergency and putting in place the Graded Response Action Plan (Grap) in the National Capital Region (NCR), following directions of the Supreme Court.
In 2020, Delhi saw nine severe days in November, and seven in 2019, historical data showed. In 2018, five severe air quality days were seen in Delhi, while this number was seven in 2017.
Delhi has not seen a single day of moderate air quality this November.
The air has been this poor likely because of the late withdrawal of monsoon and a delay in the burning of farm residue in north Indian states, experts said. The number of farm fires usually drops around the middle of the month, but has only just subsided this year.
“We saw a slow start to the stubble fires this season. Usually by November, the farm fires in Punjab and Haryana start declining. But this time, in October there weren’t many fires, but by first week of November it started increasing,” said Anumita Roychowdhury, executive director of research and advocacy at Centre for Science and Environment, a non-profit.
The pollution peak, however, is largely because of local pollutants in Delhi-NCR, she pointed out.
“Currently, the stubble fire share in Delhi’s PM2.5 levels [ultra fine particulate matter] is only about 2-6%, which means that the severe pollution levels that we are seeing now is a result of local pollution in all of Delhi-NCR,” she said.
PM 2.5, or particulate matter less than 2.5 micrometres, can enter deep into the lungs and bloodstream, and cause serious health problems.
“We need targeted action against local pollution sources, and measures will have to be implemented with greater vigour by agencies,” Roychowdhury said.
While the number of severe air days was higher this year, the spells of continuous severe AQI days that last for over two days were for shorter durations, but were more recurrent.
Delhi saw its first severe spell from November 5, a day after Diwali, to November 7. The next spell, which also lasted three days, continued from November 11 till November 13. The capital city and its neighbouring areas saw another severe air spell that started on November 25, and with Saturday’s AQI recording of 402, continued again for three days.
Air pollution will continue to be dangerously high at least till November 29, the India Meteorological Department has predicted.
Along with stubble fires, the local weather this month was also unfavourable for dispersal of pollutants, explained VK Soni, head of the weather bureau's environment and research centre. Delhi this month saw several days when slow and calm winds were recorded, he said.
“While November generally is a bad month for pollution, this time we also saw slow and calm winds on many days,” Soni said. “The forecast says that improvement is unlikely before November 29-30. The pollution levels are likely to remain in the upper end of very poor category.”
Delhi government spokespersons did not respond to requests seeking comment.
A senior Delhi Pollution Control Committee (DPCC) official said, “Keeping in mind the dangerous rise in pollution levels, we ordered a ban on construction in Delhi and this ban was later also put in place by the Commission for Air Quality Management (CAQM). We also banned the entry of trucks carrying non-essential items into Delhi and also ordered the closure of schools.”
HT approached officials in the Union environment ministry and CAQM for comment on whether new measures will be taken to reduce severe air pollution levels, but they declined to comment and said measures are already being taken and that the Supreme Court was informed.