Post-Diwali air quality better than 2021 in several cities, shows CPCB data

Delhi air quality 'very poor' the day after; improvement over previous years

This Diwali has brought a whiff of optimism. A smaller share of Indian cities had poor air quality after Diwali than in 2021.

Around 39 per cent of cities recorded poor air quality or worse on the day after Diwali, compared to 55 per cent in 2021, shows an analysis of data from the Central Pollution Control Board (CPCB).

Air quality in 73 cities fell in “poor”, “very poor” or “severe” categories the day after Diwali in 2021, out of 133 cities for which data is available. This figure dropped to 66 cities out of 171 in 2022. Many have moved out of worse categories into “poor”.

Air quality in Delhi and cities around was “very poor” on Tuesday afternoon, as data showed that the pollution had improved from the past few years but was still “very unhealthy”.

Delhi’s air quality index (AQI) was 317 at 12.30 pm and 303 at 4 pm on Tuesday, according to CPCB data. This places it in the “very poor” category. It had been in the “severe” category last year. Other cities that recorded “very poor” air quality were Bulandshahr with an index value of 331, followed by Dharuhera (318), Jodhpur (337), and Kurukshetra (301). Delhi’s neighbouring cities of Ghaziabad (270), Noida (305), Gurugram (307) and Faridabad (305) reported “poor” to “very poor” air quality — pollution levels that are “unhealthy” and “very unhealthy”.

An AQI between zero and 50 is considered “good”, 51 and 100 “satisfactory”, 101 and 200 “moderate”, 201 and 300 “poor”, 301 and 400 “very poor”, and 401 and 500 “severe”.

According to the CPCB, Delhi's AQI on Diwali on Monday was the best in four years and the second best in seven years for a festival date. The air quality plunged at night when firecrackers were set off in several parts of the national capital despite a ban.

Delhi’s AQI reached 365 at midnight for a “very poor” tag, according to data from the state-run System of Air Quality and Weather Forecasting and Research.

Delhi recorded an AQI of 382 on Diwali last year. The AQI was 414 in 2020, 337 in 2019, 281 in 2018, 319 in 2017, and 431 in 2016, according to CPCB.

The concentration of poisonous PM2.5 particulate matter was 15 times more than safe limits in the 24-hour period starting Monday, according to data from the Delhi Pollution Control Committee. PM2.5 is small enough to permeate deep into the lungs, enter the bloodstream, and can cause severe respiratory diseases, including lung cancer.

As many as 201 calls about fires were received in Delhi during Diwali, Atul Garg, director of Delhi Fire Service, told the media. “Post-midnight till 6 am today (Tuesday), we received 63 more fire calls. It was an overall peaceful Diwali,” Garg said.

On Tuesday, the Municipal Corporation of Delhi began pollution control measures by sprinkling water in several places in the capital.

Stubble burning — one source of pollution in northern India — is increasing in farms. According to the Indian Agricultural Research Institute’s real-time monitoring, 7,842 fires were recorded in six paddy-growing states — Punjab, Haryana, Uttar Pradesh, Rajasthan, Madhya Pradesh and Delhi — between September 15 and October 25, as against 8,762 cases recorded during the same period last year.

On Monday, Punjab reported the season’s most stubble burning cases (1,019) on a single day.

According to IQAir data, India ranks fifth out of 117 countries in terms of air pollution. Only three countries met the World Health Organization (WHO) guidelines on air quality in 2021. The five worst performers — Bangladesh, Chad, Pakistan, Tajikistan and India — exceeded the WHO level by over 10 times.