Delhi's air quality improves slightly due to higher wind speed

A day after Diwali, the air quality in Delhi and surrounding areas turned “hazardous" on November 5 as people burst firecrackers on the festival of lights in a blatant disregard to the government's ban on it amid a sharp increase in fumes from farm fires. The overall air quality index in the national capital was 617 in the morning and entered the ‘hazardous’ category, reported CNN_News18 citing data from System of Air Quality and Weather Forecasting and Research (SAFAR).(Image: Reuters)

The air quality in the national capital improved slightly on November 6 due to higher wind speed. According to Central Pollution Control Board's (CPCB) Sameer app, the city's air quality index (AQI) stood at 449 in the severe category at 8 am on Saturday. It was 462 on Friday.

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'.

A day after Diwali, the air quality in Delhi and surrounding areas turned “hazardous" on November 5 as people burst firecrackers on the festival of lights in a blatant disregard to the government's ban on it amid a sharp increase in fumes from farm fires.

The overall air quality index in the national capital was 617 in the morning and entered the ‘hazardous’ category, reported CNN_News18 citing data from System of Air Quality and Weather Forecasting and Research (SAFAR).

On the day of Diwali, the city's air quality index, which stood at 382 at 4 pm, entered the severe zone around 8 pm as low temperature and wind speed allowed the accumulation of pollutants. The neighbouring cities of Faridabad (424), Ghaziabad (442), Gurgaon (423) and Noida (431) also recorded 'severe' air quality with cracker bursting peaking after 9 pm.

According to the Central Pollution Control Board (CPCB), the 24-hour average PM2.5 concentration in Delhi-NCR rose from 243 micrograms per cubic meter at 6 pm to 263 micrograms per cubic meter at 9 pm, more than four times the safe limit of 60 micrograms per cubic meter. The national capital's 24-hour average air quality index (AQI) stood at 382 on November 4, up from 314 on November 3. It was 303 on November 2 and 281 on November 1.

At around 3 am, the air quality at Janpath fell to the ‘hazardous’ category with PM2.5 at 655.07, as per the report.

People from several parts of the city and its suburbs complained of itchy throat and watery eyes, as a layer of smog, the first episode this season, lingered over the region. Residents of Lajpat Nagar in South Delhi, Burari in North Delhi, Paschim Vihar in West Delhi, and Shahdara in East Delhi reported incidents of firecracker bursting as early as 7 pm, despite the blanket ban in the national capital till January 1, 2022.

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 SAFAR model forecasts, stubble burning share may increase to 35 per cent on Friday and 40 per cent on Saturday with the wind direction changing to northwesterly.

Northwesterly winds carry smoke from farm fires in Punjab and Haryana towards the national capital. Relief is expected only from the evening of November 7 but AQI will fluctuate within the 'very poor' range, the air quality forecast agency said.

In 2020, the share of stubble burning in Delhi's pollution had peaked at 42 percent on November 5. In 2019, crop residue burning accounted for 44 percent of Delhi's PM2.5 pollution on November 1. The contribution of stubble burning in Delhi's PM2.5 concentration was 32 percent on Diwali day in 2020 as compared to 19 percent in 2019.

(With inputs from PTI)