Air quality in Delhi dives even as paddy harvesting season comes to an end

Centre’s air quality panel says the overlap of Deepavali with peak harvesting activity led to drop in city’s air quality; experts say more financially viable options could further reduce farm fire cases

Air pollution in the Capital on Thursday was over 13 times the permissible limit set by the World Health Organization (WHO), according to official data. The city’s air quality, which had improved over the past few days owing to spells of rain and strong winds, worsened over the day even as the contribution of stubble burning to Delhi’s air pollution was minimal with the paddy harvesting season (September 15-November 30) coming to an end.

The Centre’s air quality panel — Commission for Air Quality Management in NCR and Adjoining Areas (CAQM) — said the number of farm fire incidents this year during the paddy harvest season fell in Punjab and Haryana by 27% and 37%, respectively.

Punjab has recorded a drop in such incidents for the third straight year and Haryana for the second consecutive year, as per the CAQM data.

The air quality panel gave several reasons for the continued drop in the cases of crop residue burning. These include the formulation of district-specific action plans, intensified monitoring at the level of the Chief Secretary, Deputy Commissioners, and other officers concerned, and the availability of machines to utilise paddy straw for industrial purposes.

Vinay Kumar Sehgal, Principal Scientist at the Indian Agricultural Research Institute (IARI), said they expect the trend of the decline in farm fire cases to hold in the future as well. He added that the practice of using stubble for various industries is also rising. “However, to reach almost zero stubble-burning incidents, we have to come up with more economically viable options for farmers, industries, and entrepreneurs,” Mr. Sehgal added.

Mix of factors

The daily average air quality in Delhi was at its best during the 11 months from January to November this year compared to the corresponding period during the past six years, barring the pandemic-affected year of 2020, the CAQM said.

However, it added that in November, “The peak of the paddy harvesting activity in Punjab and Haryana coincided with the festival of Deepavali this year, further aggravating the air pollution scenario in Delhi/NCR.”

Poisonous particles

The concentration of poisonous pollutant PM2.5 in the city on Thursday was over 13 times the WHO’s permissible limit.

The contribution of stubble burning to PM2.5 in Delhi on Wednesday was only 2.1%, compared to a high of 35.4% earlier this month, according to Ministry of Earth Sciences data. It is estimated to be 2.4% on Thursday.

The air quality index (AQI) of the national capital slipped into the ‘severe’ category by Thursday evening from the upper end of the ‘very poor’ category in the morning. The AQI is likely to be ‘very poor’ for the next two days, according to official data.

‘Severe’ category air affects healthy people and “seriously impacts those with existing diseases”, according to the Central Pollution Control Board (CPCB).

Delhi’s overall 24-hour average AQI was 398 (‘very poor’) at 4 p.m. on Thursday and increased to 401 (‘severe’) by 10 p.m. on Thursday, as per the CPCB’s data. A higher value of AQI means an increase in air pollution. An AQI reading between 301 and 400 is considered ‘very poor’ and between 401 and 450 ‘severe’.